THE AFRICAN HERBAL INDUSTRY:
CONSTRAINTS AND CHALLENGES
By Ernest Rukangira
Director, Conserve Africa
Note:
This paper was prepared for
presentation at “The natural Products and
Cosmeceutcals 2001 conference”. It was published in “Erboristeria
Domani”, August 2001.
ABSTRACT
The majority of people in Africa use plant based
traditional medicines for their care. Demand for medicinal plants is increasing
in Africa as the population grows. The threat posed by over-exploitation of
medicinal plants has serious implications on
the survival of several plant species, many of which are faced with
extinction. The pharmaceutical potentials of African medicinal plants are
immense. But constraints and challenges exist at all levels. This paper
discusses these constraints and challenges in relation to conservation, science
and technology, use of medicinal plants at the local level, the domestic drug
production sector, marketing, safety and
efficacy requirements. Measures and
strategies for enhancing the development of a medicinal and aromatic plants
industry in Africa are suggested.
I. MEDICINAL PLANT USE IN
AFRICA
In all countries
of the world there exists traditional knowledge related to the health of humans
and animals. The importance of
traditional medicine as a source of primary health care was first officially
recognised by the World Health Organization (WHO) in the Primary Health Care
Declaration of Alma Ata (1978) and has been globally addressed since 1976 by
the Traditional Medicine Programme of the WHO. That Programme defined
traditional medicine as: “the sum total of all the knowledge and practices,
whether explicable or not, used in diagnosis, prevention and elimination of
physical, mental or social imbalance and relying exclusively on practical
experience and observation handed down from generation to generation, whether
verbally or in writing.”
In Africa,
traditional healers and remedies made from plants play an important role in the
health of millions of people. The relative ratios of traditional practitioners
and university-trained doctors in relation to the whole population in African
countries are revealing. In Ghana, for example, in Kwahu district, for every
traditional practitioner there are 224 people, compared to one university
trained doctor for nearly 21,000 people.
The same applies to Swaziland where the ratios are 110 people for every
traditional healer and 10,000 people for every university-trained doctor. It is estimated that the
number of traditional practitioners in Tanzania is 30 000 - 40 000 in
comparison to 600 medical doctors. In Malawi, there are 17 000 traditional
medical practitioners and only 35 conventional medical doctors in practice.
Relegated for a long time
to a marginal place in the health planning of developing countries, traditional
medicine or more appropriately, traditional systems of health care, have
undergone a major revival in the last twenty years. Every region has had, at
one time in its history, a form of traditional medicine.
We can therefore talk of
Chinese traditional medicine, Arabic traditional medicine or African
traditional medicine. This medicine is
traditional because it is deeply rooted in a specific socio-cultural context,
which varies from one community to another.
Each community has its own particular approach to health and disease
even at the level of ethno-pathogenic perceptions of diseases and therapeutic
behaviour. In this respect, we can argue
that there are as many traditional medicines as there are communities. This
gives traditional medicine its diverse and pluralist nature.
The World Health
Organisation (WHO) has described traditional medicine as one of the surest
means to achieve total health care coverage of the world's population. In spite
of the marginalisation of traditional medicine practised in the past, the
attention currently given by governments to widespread health care application
has given a new impetus to research, investment and design of programmes in
this field in several developing countries.
The demand by majority of the people in developing
countries for medicinal plants has been met by indiscriminate harvesting of
spontaneous flora including those in forests. As a result, many plant species
have become extinct and some are endangered. It is therefore necessary that
systematic cultivation of medicinal plants be introduced in order to conserve
biodiversity and protect threatened species. Systematic cultivation of these
plants could only be initiated if there is a continuous demand for the raw
materials.
As Africa's population
grows, demand for traditional medicines will increase, and pressure on
medicinal plant resources will become greater than ever. While loss of habitat
is the major factor contributing to the depletion of natural resources in
Africa, collection of wild plants for traditional medical use is extremely
detrimental to certain species.
Table 1: Medicinal plants
used by majority of the population and frequently cited by most traditional
healers in Tanzania
|
Plant Part
used Uses
|
|
|
|
1.
Cassis didymobotria L. Leaves Anemia,
Athlemintic, laxative
|
|
2.
Ficus stulhmanii Walp. Stem
bark Treats chronic
wounds
|
|
3.
Harrisonia abysinica Oliv. Roots Bilharzia,
chronic wounds
|
|
4.
Terminalia serica Burch. Roots Diarrhea,
vomiting, stomach problems
|
|
5.
Securidaca longipenduculata Roots Treats
infertility in both men and women
|
|
6.
Euphporbia quadrangularis pax Arial
parts General body
weakness
|
|
7. Entada abyssinica
Steud. Root
bark Chronic cough,
headache, stomach pains
|
|
8.
Albizia vesicolor Welw. Root
bark Anemia,
Athlemintic, sterility in women
|
|
9.
Strychino heterodoxa Gilg. Roots Inflammations and
fevers
|
|
10.
Gnidia kraussiana Tuber Constipation,
swollen stomach
|
Source: Nshimo
, 1888
Documentation of medicinal
use of African plants is becoming increasingly urgent because of the rapid loss
of the natural habitat for some of these plants due to anthropogenic
activities. The continent is estimated to have about 216,634,00 ha. of closed forest areas and with a calculated
annual loss of about 1% due to deforestation, many of the medicinal plants and
other genetic materials become extinct before they are even documented.
Majority of the plants found in Africa are endemic to that continent,
the Republic of Madagascar having the highest rate of
endemism (82%). Undoubtedly, medicinal plants
and the drugs derived from them constitute great economic and strategic value for the African continent.
Africa has a long
and impressive list of medicinal plants. Securidaca Longepedunculata is
a tropical plant found almost everywhere in Africa. The dried bark and root are
used in Tanzania as a purgative for nervous system disorders. One cup of its
root decoction is administered daily for two weeks. Throughout East Africa, the
plant's dried leaves are used for wounds and sores, coughs, venereal diseases
sand snakebite. In Malawi, the leaves are used for wounds, coughs, bilharzia,
venereal diseases, snakebite and headaches while in Nigeria they are used for
skin diseases. According to one pharmaceutical researcher, the root is used in
"Bechuanaland" and "Rhodesia" for malaria while the same
part of the plant is used for impotence in "Tanganyika". Meanwhile,
in Angola, the dried root is used as both a fish poison and (in botanical
testimony to the power of love) as an aphrodisiac. The same dried roots have
religious significance in Guinea-Bissau and are understood to have a
psychotropic effect. The root bark is used for epilepsy in Ghana.
Table 2.Plants that are
of common use in Africa and Madagascar; Source:
Safowora, 1996.
|
The Abrus precatorius L. (Leguminosae)
Acacia senegal (L.)Wild. (Mimosaceae)
Acokanthera ongiflora Stpf.
(Apocynaceae)
Adansonia digitata L. (Bombaceae)
Agave sisalana Perine, ex Engelm.
(Amaryllidaceae)
Ageratum conyzoides L. (Asteraceae)
Albizia anthelmintica A. Brongn.
(Mimosaceae)
Quelques plante médicinales communes
Allium sativum L. (Liliaceae)
Aloe ferox Mill. (Liliaceae)
Alstonia boonei de Wild. (Apocynaceae
)
Ammi visgana Lam. (Apiaceae)
Anchomanes difformis Engl. (Araceae)
Arachis hypogea L. (Lguminosae)
Aristolochia bracteata Retz.
(Aristolochiaceae)
Astralagus gumifer Labill. (Fabaceae)
Azadirachta indica A. Juss. (Meliaceae
)
Balanites aegyptiaca Del.
(Zygophyllaceae)
Boerhavia diffusa Engelm. & A.
Gray (Nyctaginaceae)
Borreria verticillata L.G.F.W. Mey (
Rubiaceae)
Calotropis procera Ait. F.
(Asclepiadaceae)
Carapa procera Ait.f. (Meliaceae)
Capsicum minimum Mill. (Solanaceae)
Carica papaya L. (Caricaceae)
Carum carvi L. (Apiaceae)
Cassia senna L. (Leguminosae)
Catharanthus roseus G. Don
(Apocynaceae)
Chenopodium ambrosioides L.
(Chenopodiaceae)
Chrysanthemum cinerariaefolium
Vis. (Compositae)
Cinchona succirubra Pavon. (Rubiaceae)
Cinnamomum zeylanicum Blume
(Lauraceae)
Centella coreaceae Nannfd. (Apiaceae)
Crinum jagus (Thoriper) Dandy
(Amaryllidaceae)
Cryptolepis sanguinolenta (Lindl)
Schtlr. (Periplocaceae)
Cymbopogon citratus Stapf (Graminae)
Datura stramonium L. (Solanaceae)
Euphorbia kamerunica pax
(Euphorbiaceae)
Funtumia elastica Stapf. (Apocynaceae)
Glinus lotoides L. (Mollugo hirta L.)
(aizoaceae)
Harrisomia abyssinica Oliv.
(Simarubaceae)
Heliotropum indicum L. (Boraginaceae)
Hyoscyamus muticus L. (Solanaceae)
Jatropha curcas L. (Euphorbiaceae)
Kalanchoe crenata (Andr.) Haw.
(Crassulaceae)
Lawsonia inermis L. (Lythraceae)
Mitragyna stipulosa (DC) O. Ktze
(Rubiaceae)
Momordica charantia L. (Cucurbitaceae)
Morinda lucida Benth. (Rubiaceae)
Moringa pterygosperma Gaertn.
(Moringaceae)
Nauclea latifolia Sm. (Rubiaceae)
Nicotiana tabacum L. ( Solanaceae)
Nymphaea lotus L. (Nymphaeaceae)
Ocimum gratissimum L. (Lamiaceae)
Olea europea L. (Oleaceae)
Parquetina nigrescens (Afz) Bulloch
(Periplocaceae)
Peganum harmala L. (Zygophyllaceae)
Pergularia daemia Choiv. (Asclepiadaceae)
Plumbago zeylanica L. (Plumbaginaceae)
Phytostigma venenosum Balf.
(Leguminosae)
Phytolacca dodecandra I. Herit.
(Phytolaccaceae)
Piper guinense C.D.C. (Piperaceae)
Rapanea melanophloeos Mez.
(Myrsinaceae)
Rauwolfia vomitoria Afz. (Apocynaceae)
Ricinus communis L.(Euphorbiaceae)
Securidaca longipedunculata Fresen.
(Polygalaceae)
Securinega virosa (Roxb. Ex Willd.)
Baill.
(Euphorbiaceae)
Solanum nigrum L. (Solanaceae)
Spondias mombin L. (Anacardiaceae)
Strophanthus Kombe Oliv. (Apocynaceae)
Strychnos nux-vomica L. (Loganiacee)
Syzygium aromaticum L. (Myrtaceae)
Terminalia glaucescens Planch. Ex
Benth.
(Combretaceae)
Thalictrum rhynchocarpum Q. Dillon A.
Rich
(Ranunculaceae)
Thea sinensis Camellia (L.) O. Kuntze
(Theaceae)
Theobroma cacao L. (Sterculiaceae)
Trema orientalis Blume (Ulmaceae)
Triclisia gilletii (De Willd.) Staner
(Menispermaceae)
Voacanga africana Stapf. (Apocynaceae)
Warburgia ugandensis Sprague
(Canellaceae)
Withania somnifera Dun. (Solanaceae)
Ximenia americana L. (Olacaceae)
Zanha golungensis Hiern (Sapindaceae)
Zanthoxylum (Fagara) Zanthoxyloides
Waterman
(Rutaceae)
Zingiber officinale Roscoe
(Zingiberaceae)
|
In Africa, parts of medicinal plants
can be seen at every market in urban and peri-urban centres these days.
Traditional healers are now becoming more professional and organised making it
easier to approach if only to seek information.
The market for indigenous medicinal plants will continue to grow to
absorb the products from the producers.
In
1996, TRAFFIC East/Southern Africa - the wildlife trade monitoring programme of
WWF and IUCN - initiated an 18-month review of trade in wildlife medicinal
resources in East and Southern Africa and Madagascar with the aim of
identifying species most in need of conservation, management and/or research.
This review also entailed collecting information about trade patterns, markets,
source areas and impacts of harvest. Relevant information was collected in 17
countries: Botswana, Eritrea, Ethiopia, Kenya, Lesotho, Madagascar, Malawi,
Mozambique, Namibia, Somalia, South Africa, Sudan, Swaziland, Tanzania, Uganda,
Zambia and Zimbabwe.
The study, published in
the September 1998 Species in Danger Report “Searching for a cure:
Conservation of medicinal wildlife resources in East and Southern Africa”,
identified 102 medicinal plant species and 29 medicinal animal species as
priorities for conservation and management action.
Plant species range from
the well-known afromontane tree Prunus africana, to the Sudanese
succulent Aloe Sinkatana, valued locally to treat a variety of ailments
including skin diseases, fever, constipation and inflamed colon. Species
regarded as common in some countries have also been identified as becoming
scarce in others, such as the Baobab (Adansonia digitata), which despite
its wide distribution is experiencing a decline in Eritrea and Sudan.
This study revealed that
use of wildlife medicinal resources in East and Southern Africa is largely for
traditional medicine while a few species are being exported. Traditional
medicine is the most widely used medical system in the region. Not only is
traditional medicine popular and accepted, but also in many areas it is the
only system available. Western medicine is costly and often inaccessible. The
vast majority of plants and animals used in traditional medicine, as well as
those exported from the region, are collected from the wild. Some plant species
are also cultivated on farms, for example as hedgerows but this supply is still
insufficient to meet growing demand. There are reports of increasing scarcity
for many of these wildlife medicinals, and this situation represents a concern
not only from the conservation point of view, but also because reduced
availability of wildlife medicinals will have a negative effect on the health
status of many people living in East and Southern Africa.
Table 3. TRAFFIC Evaluation of priority plant
species in the region
|
Species
|
Countries reporting
concern
|
Species
|
Countries
resporting
concern
|
|
ZINGIBERACEAE
|
|
SAPOTACEAE
|
|
|
Siphonochilus
aethiopicus
|
SW, ZA
|
Chrysophyllum
boivinianum
|
MG
|
|
AMARYLLIDACEAE
|
|
GUTTIFERAE
|
|
|
Boophone disticha
|
ZA
|
Psorospermum febrifugum
|
UG
|
|
Clivia miniata
|
ZA
|
MYRSINACEAE
|
|
|
ASPHODELACEAE
|
|
Rapanea melanophloeos
|
ZA
|
|
Aloe polyphylla
|
LE
|
CAPPARIDACEAE
|
|
|
Aloe sinkatana
|
SD
|
Boscia salicifolia
|
KE
|
|
Haworthia limifolia
|
ZA
|
B. senegalensis
|
SD
|
|
DRACAENEACEAE
|
|
Cadaba farinosa
|
TZ
|
|
Dracaena steudneri
|
ET
|
Capparis erythrocarpos
|
UG
|
|
HYACINTHHACEAE
|
|
SALVADORACEAE
|
|
|
Boweia volubilis
|
ZA
|
Salvadora persica
|
SD
|
|
Eucomis autumnalis
|
LE, ZA
|
PITTOSPORACEAE
|
|
|
Scilla natalensis
|
LE, ZA
|
Pittosporum mannii
|
UG
|
|
DIOSCOREACEAE
|
|
P. senacia
|
MG
|
|
Dioscorea dumetorum
|
TZ
|
P. virdiflorum
|
MG
|
|
ORCHIDACEAE
|
|
ANISOPHYLLEACEAE
|
|
|
Ansellia africana
|
MZ
|
Anisophyllea fallax
|
MG
|
|
Vanilla decaryena
|
MG
|
CRASSULACEAE
|
|
|
V.madagascariensis
|
MG
|
Kalanchoe integrifolia
|
MG
|
|
CUPRESSACEAE
|
|
ROSACEAE
|
|
|
Juniperus procera
|
ER
|
Hagenia abyssinica
|
ET
|
|
STANGERIACEAE
|
|
Prunus africana
|
KE, UG, MG
|
|
Stangeria eriopus
|
ZA
|
LEGUMINOSAE
|
|
|
CANELLACEAE
|
|
Acacia mellifera
|
TZ
|
|
Cinnamosma macrocarpa
|
MG
|
Acacia seyal
|
SD
|
|
Warburgia salutaris
|
MZ, ZA, ZW, SW
|
Aeschynomeme abyssinica
|
MW
|
|
W. stuhlmannii
|
KE
|
Albizia brevifolia
|
NA
|
|
W. ugandensis
|
KE, UG
|
Baudouinia rouxevillei
|
MG
|
|
LAURACEAE
|
|
Caesalpinia volkensii
|
KE
|
|
Cryptocarya aromatica
|
MG
|
Cassia abbreviata
|
MW
|
|
Ocatea bullata
|
ZA
|
Dalbergia
madagascariensis
|
MG
|
|
HYDNORACEAE
|
|
Delonix adansonioides
|
MG
|
|
Hydnora abyssinica
|
SD
|
Dolichos trinervatus
|
MW
|
|
MENISPERMACEAE
|
|
Elephantorrhiza
elephantina
|
ZW
|
|
Burasaia madascariensis
|
MG
|
E. goertzii
|
ZW
|
|
Jateorhiza bukobensis
|
MW
|
Erythrophleum
suaveolens
|
MW
|
|
PASSIFLORACEAE
|
|
Lanchocarpus bussei
|
UG
|
|
Adenia olaboensis
|
MG
|
Swartzia
madagascariensis
|
ZW
|
|
CUCURBITACEAE
|
|
PROTEACEAE
|
|
|
Kedrostis foetidissima
|
KE
|
Protea gaguedi
|
NA
|
|
Momordica balsamina
|
NA
|
GUNNERACEAE
|
|
|
DROSERACEAE
|
|
Gunnera perpensa
|
LE
|
|
Drosera
madagascariensis
|
MG
|
COMBRETACEAE
|
|
|
BOMBACACEAE
|
|
Terminalia brownii
|
SD
|
|
Adansonia digitata
|
SD, ER
|
CORNACEAE
|
|
|
MORACEAE
|
|
Curtisia dentata
|
ZA
|
|
Ficus pyrifolia
|
MG
|
CELASTRACEAE
|
|
|
Milicia excelsa
|
TZ
|
Apodostigma pallens
|
UG
|
|
EUPHORBIACEAE
|
|
Maytenus buchananii
|
UG
|
|
Acalypha fruticosa
|
TZ
|
M. senegalensis
|
UG
|
|
THYMELAEACEAE
|
|
RHAMNACEAE
|
|
|
Synaptolepis kirkii
|
ZA
|
Rhamnus prinoides
|
KE
|
POLYGALACEAE
|
|
ASCLEPIADACEAE
|
|
|
Securidaca
longipedunculata
|
UG, ET, KE
|
Asclepias glaucophyllus
|
ZW
|
|
SAPINDACEAE
|
|
Fockea angustifolia
|
NA
|
|
Zanha africana
|
KE
|
Solenostemma argel
|
SD
|
|
BURSERACEAE
|
|
BORAGINACEAE
|
|
|
Comniphora glaucesens
|
NA
|
Ehretia amoena
|
TZ
|
|
C. mollis
|
NA
|
LAMIACEAE
|
|
|
ANACARDIACEAE
|
|
Hoslundia opposita
|
UG
|
|
Rhus lancea
|
ZW
|
Plectranthu
pseudomarrubioides
|
KE
|
|
Rhus natalensis
|
UG
|
PEDALIACEAE
|
|
|
Rhus vulgaris
|
UG
|
Harpagophytum
procumbens
|
BW, NA
|
|
SIMAROUBACEAE
|
|
H. zeyheri
|
BW, NA
|
|
Balanites aegyptiaca
|
SD, ER
|
COMPOSITAE
|
|
|
MELIACEAE
|
|
Brachylaena ramiflora
|
MG
|
|
Khaya senegalensis
|
SD
|
Dicoma anomala
|
MW, LE
|
|
PTAEROXYLACEAE
|
|
Wedelia mossambicensis
|
TZ
|
|
Cedrelopsis grevei
|
MG
|
RUBIACEAE
|
|
|
RUTACEAE
|
|
Gardenia spatulifolia
|
NA
|
|
Haplophyllum
tuberculatum
|
SD
|
Rubia cordifolia
|
ZW
|
|
Harrisonia abyssinica
|
KE, TZ
|
Tarenna
madagascariensis
|
MG
|
|
Zanthoxylum chalybeum
|
KE, UG
|
|
|
|
Z. gillettii
|
KE
|
|
|
|
Z. usambarense
|
KE
|
|
|
|
UMBELLIFERAE
|
|
|
|
|
Alepidea amatymbica
|
ZW, LE, SW, ZA
|
|
|
|
Steganotaenia araliacea
|
KE, TZ, MW
|
|
|
|
GENTIANACEAE
|
|
|
|
|
Anthocleista
madagascariensis
|
MG
|
|
|
|
APOCYNACEAE
|
|
|
|
|
Cabucala erythrocarpa
|
MG
|
|
|
|
Cerbera venevifera
|
MG
|
|
|
|
Holarrhena pubescens
|
MW
|
|
|
|
Rauvolfia conferiflora
|
MG
|
|
|
|
R. oxyphylla
|
UG
|
|
|
|
R. vomitoria
|
UG
|
|
|
|
|
|
|
|
Source: Marshall, N.T. (1998).
Some of the
general constraints with regard to medicinal plants and traditional medicine
can be summarised as follows:
Some of the constraints
associated with the processing of medicinal plants which may result in reducing
their competitiveness in global markets and which have to be remedied are
(Tuley de Silva, 1997):
- Indiscriminate harvesting and poor
post-harvest treatment practices.
- Lack of research on the
development of high-yielding varieties, domestication etc.
- Poor agriculture and propagation
methods.
- Inefficient processing techniques
leading to low yields and poor quality products.
- Poor quality control procedures.
- High-energy losses during
processing.
- Lack of current good manufacturing
practices.
- Lack of R & D on product and
process development.
- Difficulties in marketing.
- Lack of trained personnel and
equipment.
- Lack of facilities to fabricate
equipment locally.
- Lack of access to latest
technological and market information
II. AFRICAN NATURAL
COSMETICS
Local peoples' perception
and attitude towards skin care/beauty
Skin care practice
in Africa is undertaken under several
different practices. Among the common practices are:
Skin care and beauty
Skin care for beauty reason
is common among females and particularly among urban dwellers. This is partly
so because skin care perception among rural communities is closely associated
with sexuality. The more a female cares for her skin, the more sexually active
she is presumed to be. In a rural society where marriage is strictly guarded,
skin care practices are at a low scale.
Skin care and individual
peace of mind
A number of persons
especially in urban areas undertake skin care practices for personal
satisfaction and peace of mind. Skin care products on the market are favoured
choices.
Skin care for newborn
baby care
A common practice for
skin care among newborn babies is associated with the perception that it
protects the new born from illness. Herbs that are used daily to bathe and soak
the newborn for 'skin care' may have relatively safe effects.
Skin care for secondary
purposes
It is interesting that
skin care in some communities is undertaken as a secondary activity. Cultural
practices that range from heaping/digging potatoes, beer /wine making while
using bare feet, to purposeful application of 'mud' during cultural rituals,
care for pregnant mothers and new born, are known to have positive impact on
skin appearance. Local techniques are therefore available that combine aspects
of skin care using specific mineral and plant extracts for skin care.
Challenges in skin care
in Africa
Demand for skin care
products for skin toning and rejuvenating damaged or aged skin is a new area of
concern in Africa. There has been a surge in skin care products to the extent
that misuse of skin care products has emerged. De-pigmentation of skin and
especially the face is a common problem especially among urban females. Partial
cause for this problem is inadequate public education and an inadequate
regulatory mechanism. Interests to refer to natural products for skin care is
therefore an emerging area. Strategic mechanisms to harness available natural
plant-based products for skin care and treatment is an urgent area to be
addressed. Coupled with that is the need for conservation of the commonly
harvested species.
Table 4. Some plants used as cosmetics in
Mozambique
Scientific name Family Use Part Used
|
|
|
|
1. Diurocaryum
zanguebarium Pedaliace Shampoo Leaves, stem
|
|
2. Sesanum
alatum Pedaliacea Shampoo Leaves
|
|
3. Albizia
versicolor
Leguminosae
Detergent Bark,
roots
|
|
4. Securidaca
longepediculata
Polygalaceae
Detergent Roots
|
|
5. Olax dissitiflora
Beauty Cream Stem's
powder
|
|
6. Euclea natalensis Ebenaceae Dentifrice Roots
|
|
7. Diospyros vellosa Ebenaceae Dentifrice Roots
|
|
8. Vepris lanceolata Rutaceae Aromatic Leaves
|
|
9. Zanthoxylon
capensis
Aromatic Leaves, bark
|
|
|
In Mauritius lay people
routinely use the following plants as cosmetics:
- Henna (Lawsonia inermis):
The juice extracted from the leaves of the plant is mixed with lemon juice
and applied to the hair as a conditioner and also as a natural dye. The
natural dye is also used to stain hands and feet in rituals and
celebrations.
- Curcuma (Curcuma longa)
roots. The juice extracted from the roots is used as a skin conditioner
and also to prevent skin infections. Curcuma forms part of hindu mariage
rituals.
Other plants commonly
used for dermatological problems or for the improving skin conditions include:
- Sarcostemma viminale (Asclepiadaceae): To remove
warts.
- Agave sisalana (Agavaceae), Centella asiatica
(Apiaceae), Ipomoea pes-caprae
(Convolvulaceae): Improves skin conditions and heals.
- Acacia concinna (Leguminosae), Cassytha
filiformis (Lauraceae), Jatropha curcas (Euphorbiaceae): Hair
loss.
- Aloe barbadensis (Liliaceae), Euphorbia
prostrata (Euphorbiaceae), Manihot esculenta (Euphorbiaceae):
Skin rash.
- Pongamia pinnata (Leguminosae), Plantago major,
P. lanceolata (Plantaginaceae), Danais fragrans (Rubiaceae), Gaertnera
psychotrioides (Rubiaceae), Mussaenda arcuata (Rubiaceae),
Wikstroemia indica (Thymelaceae): Skin lesions.
- Danais fragrans (Lam.) Pers. ( Rubiaceae) :
Cicatrising , treatment of skin
diseases
- Curcuma longa L. Zingiberaceae :
antiseptic
Some plants used as cosmetics in West Africa:
SAPOTACEAE
Vittelaria paradoxa
Gaertn.f.) ; Syn : Butyrospermum
parkii (G. Don) Kotshy)
LYTHRACEAE
Lawsonia inermis L
Centella asiatica (L.) Urban: cicatrising
BALSAMINACEAE:
Impatiens balsamina L. : insecticide ,
treatment of wounds.
CUCURBITACEAE
Luffa acutangula (L.) Roxb.
ERICACEAE
Agauria salicifolia (Lam.)Hook.f. ex Oliver var. salicifolia
Treatment of skin
diseases.
EUPHORBIACEAE
Acalypha indica L.
treatment of
dermatosis
LYTHRACEAE
Lawsonia inermis L : antimicrobial
MELASTOMATACEAE
Tristemma mauritianum J. F. Gmelin
(Syn.: Tristemma
virusanum Vent.) : Treatment of skin diseases
MELIACEAE
Turraea casimiriana Harms –skin diseases
MIMOSACEAE
Acacia concinna (Willd.) DC.
Skin protection,Insecticide
PAPILLIONACEAE
Desmodium triflorum (L.) DC. : dermatosis.
Pongamia pinnata (L.) Pierre: cicatrising,
insecticide
ANNONACEAE
Annona squamosa L. essential oil, perfumery
Xylopia aethiopia (Dunal) A. Rich.:
Essential oil, perfumery
APOCYNACEAE
Plumeria rubra
var.acutifolia
(Ait) Woods, essential oil, perfumery
ARECACEAE
Cocos nucifera L. Massage oil for skin and hair, washing milk
Elaies gunensis Jacq. Cleansing cream, body soap
BOMBACACEAE
Ceiba pentandra ( L) Gaertn.
Massage oil for skin, makeup remover, and tonic lotion
CAESALPINIACEAE
Cassia absus L.: Washing lotion
Cassia alata L.: shampooing
Cassia tora L. : Makeup remover
Daniella Oiliver (Rolfe) Hutch et
Dalz : Perfumery, hair care
Tamarindus indica L.:
Makeup remover
CACTACAE
Opuntia tuna Mill: Makeup remover
COCHLOSPERMACEAE
Cochlospermum tinctorium
A. Rich.
Makeup remover, tonic lotion
COMBRETACEAE
Anogeissus leiocarpus (DC) Guill. et Perr. :
Lotions
CONNARACEAE
Cnestis ferruginea DC. : Tonic lotions
CONVOLVULACEAE
Ipomea batatas (L) Lam: body cream
CUCURBITACEAE
Cucurbita citrullus L. : Body lotion, shampooing, and hair tonic
Cucurbita maxima Duchesne: hair lotion, body
lotion, shampooing
Cucurbita pepo L.: Body and hair lotion
Momordica balsamina L.: Body soap
CYPERACEAE
Cyperus articulatus L. Perfumery
Cyperus esculentus L. Body lotion and hair tonic
FABACEAE or PAPILLONNACEAE
Indigofera arrecta Hochst.ex.A. Rich: shampooing
LYTHRACEAE
Lawsonia inermis L.: shampooing, hair
tonic and perfumery
MALVACEAE
Hibuscus esculentus L: makeup remover, cream and lotion
Carapa procera D.C. Massage oil for skin and hair, hair lotion,
washing milk
MIMOSACEAE
Acacia nilotica var.
adansonii
(Gnill et Perr.) O. Ktze : tonic lotion
Albizzia lebbek Benth. Shampooing, make up remover, washing lotion
MORINGACEA
Moringa oleifera Lam.: body lotion,
washing milk, soap.
OLACACEAE
Ximenia americana L. washing milk
PAPAVERACEAE
Argemone mexicana L.: washing milk
PEDALIACEAE
Carathoteca sesamoides Endl. : Body soap
and lotion
Rogeria adenophylle J. Gay ex. Delike: body
soap, shampooing, and lotion and body milk
POACEAE
Vetiveria nigritana Stapf. : Perfumery
RUBIACEAE
Borreria verticillatta (L) G.F. W. Mey: makeup remover
Gardenia triacantha DC. : Tonic milk and lotion, shampooing
RUTACEAE
Afraegle paniculata (Shum et Thonn.)
Engl : massage oil for skin,
antiwrinkle milk and lotion
Fagara leprieurri (Gnill et Perr)
Engl. : Body and milk lotion,
after-shave
Fagara zanthoxyloides Lam: perfumery
SAPINDACEAE
Paulinnia pinnata L:
shampooing, milk and lotion tonic
SAPOTACEAE
Butyrospermum parkii (
G.Don ) Kotschy : massage oil for
skin and hair, cream, protection
against sun, emulsion after shave,
toothpaste
SOLANACEAE
Solanum aethiopicum L.:
body lotion and milk
STERCULIACEAE
Sterculi setigera Del: make up
remover
TAMARICACEAE
Tamarix gallica L. (de F.T.A): tonic milk and lotion
TILIACEAE
Corchorius olitorius L.: make remover
Grevia bicolor
Juss. : Body
milk and lotion, toothpaste
Grevia mollis Juss :
lotion
and milk makeup remover, body milk and lotion
VERBENACEAE
Vitex doniana Sweet: body and milk lotion,
toothpaste
Vitex madiensis
oliv : cream, cleansing milk, shampooing, tonic milk and
lotion
ZINGIBERACEAE
Costus afer. Ker : skin nourishing creams and milk
Balanites aegyptiaca (L.) Del: body soap, shampooing, body cleansing milks,
creams, and toothpaste
Tribulus terrestris
L. :
perfumery, hair lotion, antiwrinkle body lotion and milk ant wrinkle creams, cleansing creams
III.
CHALLENGES AND CONSTRAINTS ON AFRICAN
MEDICINAL PLANTS
Conservation and Cultivation
In order to sustain the
sensible utilisation of medicinal and aromatic plants, conservation has to be
kept as the central focus. In conducting
research and development activities, plant parts from which the extracts are
obtained have to be such that will not destroy the plant. Furthermore, the methods of harvesting the
desired plant parts should take cognisance of the conservation of the
plant. Ex situ cultivation of the
desired medicinal and aromatic plants would be necessary so as to obtain raw
plant materials grown under the same conditions of climate, ecology etc. The acquisition of large scales of land
required for ex situ cultivation from government agencies can be a serious
obstacle.
African medicinal plant
resources may be doomed to extinction by overexploitation resulting from
excessive commercialisation, habitat destruction and other natural and man made
destructive influences unless energetic conservation measures are taken to
ensure their continued availability. This can be done through the establishment
of medicinal plant gardens and farms.
The protection and
conservation of medicinal plants does not take high priority on the agenda for
natural resources management. Government
programmes give priority to agricultural and wildlife resources. This is mainly
due to the identified potential of such resources in contributing positively to
national development. On the other hand,
it could be that there is so much information about agricultural, forestry and
wildlife resources as compared to medicinal plants. This allows programmes to
be developed for those systems that are better understood. The area of
medicinal plants is left alone as a niche for traditional doctors.
Challenges in R & D
Research in chemistry and
bioactive components of medicinal plants of Africa has been ongoing for quite
some time, funded by multi-/ bi- lateral aid or non-governemental donor
organisations. A systematic and concerted approach to this activity has not
been maintained for want of sophisticated equipment and high-cost chemicals.
Much of the research has been mainly academic. The concept of applied research
in the industrial use of plants has not received much attention. Research in
support of industrial development should focus on related activities ranging
from the propagation of medicinal plants; appropriate processing technologies
to improve quality and yield, new formulations to new products and the
marketing of finished products.
The main problem facing
the use of traditional medicines is the proof requirement that the active
components contained in medicinal plants are useful, safe and effective. This
is highly required to assure the medical field and the public regarding the use
of medicinal plants as drug alternatives. The proofs of pharmacology activity
that are available at present are mostly based on empirical experience. The
scientific proof then becomes the most important thing in order to eliminate
the concern of using medicinal plants as drugs for alternative treatment.
Unfortunately, most African countries are not able to conduct research or
provide scientific proof of pharmacology. International collaboration is
important for African countries, as it would enhance the development of drugs
obtained from medicinal plants to their benefit.
Furthermore research and
training activities for traditional medicine has not received due support and
attention. As a result, the quantity and quality of safety and efficacy data
are far from sufficient to meet the demands of the use of traditional medicine
in the world.
Reasons for the lack of
research data involve not only policy problems, but also the research
methodology for evaluating traditional medicine. There is literature and data
on the research of traditional medicine in various countries, but all
scientists may not accept them. As the characteristics and application of traditional
medicine is quite different from western medicine, how to evaluate traditional
medicine and what kinds of academic research approaches and methods may be used
to evaluate the safety and efficacy of traditional medicine are new challenges
which have emerged in recent years.
The economies of most
African countries are subjected to immense and diverse pressures with varied
competing interests. Science and Technology is usually the sacrificial lamb in
view of the general notion that such investments do not yield immediate
tangible results. Generally, therefore, the funds allocated for research
equipment are indeed insignificant.
Process technology
Traditional herbal
medicines are produced by the practitioner him/herself who was able to identify
the correct plant species. As a result, there is no guarantee of the
authenticity and quantity of plant material used in the preparations. The
quality of traditional medicines so produced varies widely and may not even be
effective. Therefore, there is a need to select proper and appropriate
technologies for the industrial production of traditional medicines such that
the effectiveness of the preparation is ensured. Traditional methods used have
many disadvantages, which can be corrected by selecting suitable technologies
to make them more effective, stable, reproducible, controlled and in dosage
forms that can easily be transported. Hence the introduction of an appropriate,
simple and low-cost technology should be encouraged maintaining as much as
possible the labour-intensive nature of such activities, conservation of
biodiversity through small-scale production and preservation of cultural
knowledge.
Quality assurance
The control of the
quality of raw materials, finished products and of processes is an absolute
necessity if one is to produce goods for world markets and human consumption.
The quality requirements for medicinal plant preparation are stringent in terms
of content of active principles and toxic materials. Whereas the production of
traditional medicines for local use does not require such stringent standards,
what is produced will be a much more improved version of the already produced
medicines using traditional methods.
Quality has to be built into the whole process beginning from the
selection of propagation material to the final product reaching the consumer.
Human resource
development
Many African countries
have a core of trained personnel in the fields of chemistry, biology,
agriculture, pharmacology and pharmacy. They lack human resources in such
fields as chemical engineering and technology. This can be considered a major
constraint to industrial development.
Marketing
Marketing is an
insurmountable problem besetting the development of the plant-based industry in
African countries and marketability will be a crucial factor in determining the
failure or success of these industries. The market outlets can be for local use
or export. For local use, some products could reach the consumer directly while
others have to be either further processed or used as secondary components in
other industrial products. Hence user industries have to be promoted so that
locally produced extracts can be used to save foreign exchange needed for
importation of modern medicines. Substantial market promotion has to be
undertaken in order to penetrate the world market. There is need to initiate,
support and promote formulation and development of projects that are aiming at
value-added traditional medicinal plant products. Investment in supply and market development should be undertaken given
an assured market for indigenous medicinal products. New opportunities should
be investigated as demand grows and export opportunities investigated and
developed. Research should be carried out into the development of efficient
packaging and storage of plant medicines.
Value added products
Many
plants originating from Africa have become sources of important drugs. However, hardly any effort has been made
towards adding value to local natural products. By value-added processing,
communities in these countries would have earned more income and thereby become
more aware of the value of conserving the medicinal plants. Each medicinal and
aromatic plant that is used in abundance in local and export markets should be
thoroughly studied and continually monitored for composition of its
constituents. It is therefore of paramount importance to enhance Africa’s
capacity to do this.
Increasing local support
for R & D
Little
input is at the moment forthcoming from local sources for research and
development of medicinal and aromatic plants. Much of the meagre support is
obtained from external sources and it is therefore important that there should
be a matching fund from within. Majority of natural products chemists in Africa
are, in the main, limited to work without access to expertise for
identification of the constituents of medicinal and other plants of interest.
They are often forced to work in the absence of or with inadequate facilities,
particularly modern equipment as well as the manpower and technical resources
for maintaining them. Under such circumstances, researchers are forced to seek
the assistance of laboratories in developed countries. This situation coupled
with inadequate financial resources is a serious stumbling block to the
development of natural products research in the continent.
Patenting
The cost of patenting any
new drugs is relatively high for most African Scientists and institutions. In some cases, patent experts to advise on
the various processes are not available. Furthermore, it is also known that
plant materials cannot be patented in their native form. All those involved in
R & D of herbal medicines should take cognisance of patent right
requirements in their countries, Africa and the world. This is important in
view of the varied requirements of different Patent Licensing Offices. Although it is true that plant materials
cannot be patented in their natural form, efforts should be made to protect the
processes involved in the development of herbal medicine as well as the novel
uses of the product.
International Market
The various markets
available in the Western World for plant parts and extracts are not usually
available to institutions and companies in Africa. Also, the quality
requirements of standardised plant extracts are generally not met by most
researchers in Africa due to lack of personnel and inadequate facilities and
resources. Furthermore, the regular
supplies of plant raw materials in adequate quantities on long-term basis
cannot be guaranteed.
Pilot Plant
Many R&D institutions
and Universities in African countries do not have process facilities and are
therefore unable to pass on their R & D findings to the industry. Since
most African countries have not established pilot plants it is not possible to establish
the process technology required for upgrading the R&D findings to semi
industrial scale. Until the war in Rwanda, it was the only country known to
produce plant-derived drugs as a viable activity.
The establishment of a good
functional pilot plant needs a lot of investment. It is relatively expensive
for most institutions and researchers involved in R & D of herbal medicine
in Africa. Most entrepreneurs will not invest in phytomedicines vis-à-vis large-scale
production, commercialisation and marketing until such products have been
appropriately scaled up to pilot stage.
Lack of Basic Infrastructure
Infrastructural facilities
like water, electricity, telephone, transport, communication etc., which are
easily taken for granted in developed countries, are serious problems in
various parts of Africa. This situation hampers R&D activities to varying
degrees in different African Countries.
Political Environment
Civil unrest and change of
government, common in Africa, has affected progress in the industrialisation of
medicinal and aromatic plants in the continent.
The cases of Rwanda and Guinea have been cited as examples. The recent
civil war in Rwanda has seriously affected personnel and the productivity of
the model pilot extraction plant in Butare while political change in Guinea has
resulted in the closure of a company established to produce drugs from plants.
The political will of
governments to develop traditional medicine and medicinal plants is paramount.
Lack of government policy to develop medicinal plants industrially has been
advanced as the reason for inactivity in some countries. Appropriate
legislation and machinery to implement the provisions of the law are
responsibilities of the government. Registration of TMP, establishment of
curricular and laws to regulate traditional medicine practice all fall within
the premise of government.
Foreign investors also
consider the political situation in Africa, which they believe, is not
favourable for serious investment. As a result, the badly needed financial
resources for development of a traditional medicine industry remain a mirage.
Legislation
Despite its existence
over many centuries and its expansive use during the last decade, in most
African countries, traditional medicine, including herbal medicines, has not
yet been officially recognised, and the regulation and registration of herbal
medicines has not been well established.
Although, in most African
countries more than 80% of the population rely on traditional medicine for
their primary health care needs, the governments have not yet promulgated
edicts or decrees vis-à-vis regulation and recognition of the practice of
traditional medicine. Even in countries where there is an apparent recognition,
appropriate budgeting to facilitate the functioning of the Traditional Medicine
Board is usually inadequate or totally lacking.
In many countries in Africa,
the entire traditional medicine community seems to be operating outside the
framework of national legislation on the collection and trade in wild species.
There is also a large intra-African trade in medicinal plants, again almost
entirely outside the usual international trade controls. There is thus a need
for the formulation and development of national as well as regional policies
and legislation in terms of the trade and access to these resources if maximum
benefits are to be reaped in order for such policies to be successful.
Registration and property
rights
Many African countries do
not have procedures to register medicinal plant preparations although they are
widely used for the health care needs of majority of the people. The
regulations if any, are very stringent requiring the same standards expected of
modern medicines. WHO published guidelines for the assessment of herbal
medicines taking into account their long and extensive usage. These guidelines
should encourage developing countries to relax some of the current regulations
to be realistic in recognising the role of traditional medicines in the health
care delivery systems.
Access to information
Data on medicinal plants
is available in international journals and a number of databases. Many African
countries lack the resources to subscribe to research journals or acquire
access to these databases. In fact the data required by scientific personnel in
developing countries with respect to technologies and methods used for
processing and formulation of medicinal plants is not readily available in the
literature or in the databases as some of these are patent-protected.
IV. ACCESS AND BENEFIT
SHARING
The
Convention on Biological Diversity, has as one of its objectives, “the
conservation of biological diversity, the sustainable use of its components and
the fair and equitable sharing of the benefits arising out of the utilisation
of the genetic resource, including by appropriate transfer of relevant
technologies, and by appropriate funding”.
In recent years, many
examples of agreements on benefit sharing and access to genetic resources have
been developed. These are meant to ensure monetary and non-monetary benefits in
the short and long term to the source country and communities.
Table 6. Example of main benefits
obtained from bio prospecting (Source: FAO, 2000)
|
|
|||
|
|
Monetary benefits
|
Non-monetary benefits
|
Beneficiaries
|
|
Short-term
benefits
|
Employment in research
and development
|
Training in nursery,
agronomic techniques and sustainable sourcing strategies
|
Local communities
|
|
|
|
Training, capacity
building, infrastructure, equipment and supplies, scientific exchange, supply
of research results
|
National level
|
|
Long-term benefits
|
Potential alternative
income generating scheme, Village Development Fund (funded by potential
royalties) Potential royalties from commercial product
|
|
Local Communities
|
Short-term benefits, which are already
provided during the research and development (“prospection”) phase, are more
promising and realistic. These so-called “process” benefits include advance
payments, access fees provided in the form of lump sums or milestone payments.
Advance payments are often used to establish trust funds that can provide
immediate benefits to stakeholders. Short-term, non-monetary benefits include
capacity building, training, technology transfer, equipment, and infrastructure
and research collaboration.
Table 7. SOME IMPORTANT PLANT-BASED INGREDIENTS OF
MEDICAMENTS (Source: FAO, 2000)
Research undertakings and the commercial use
stemming from that research have always relied on
information
provided by local communities that, in many cases, have hardly benefited from
the research results. Any and all activities that seek to develop natural
products from these regions need to
incorporate
explicit reciprocal benefit programmes in early phases of their planning for
the people
and places from which the products come. TMP should be
given due recognition and support in the
development of herbal medicines. Local communities need to be convinced
about the purpose and willingness to share with them the future benefits of any
new phytomedicine under development, if it finally
scales through the clinical trial and registration processes. Training programmes
should be organised for TMP so as to
expose them to various ways of improving their formulations and practice
as well as their limitations.
V.CONCLUDING REMARKS:
In order for medicinal
plants to be accepted in the medical field as alternative drugs, pharmacology
research and the safety test of active ingredients have to be carried out.
Production of standardised phytomedicines requires specialised expertise and
pilot plant facility. Urgent action is needed for research that focuses on the
generation of baseline information on medicinal and aromatic plants and for
promoting value- added processing of herbal medicines from local materials for
local industries with simple dosage forms being standardised and packaged at
low cost using appropriate technology.
VI. APPENDICES
|
Box 2. Medicinal plants and patents in Zimbabwe
By Professor G. L.
Chavunduka
President: Zimbabwe national traditional healers
association (Zinatha)
More than 500 different
types of plants are used for medicinal purposes in Zimbabwe. Many people use
these traditional medicines every day. About 80% of the people in the country
use these plant medicines at some stage of their illness. There are about
50,000 registered traditional health practitioners in Zimbabwe. They derive
their income from harvesting, preparation and the sale of medicinal plants,
and they also attend to patients. Besides the 50,000 professional healers,
there are also hundreds of traders who derive much of their income from
selling indigenous medicinal plants at the various urban markets. The
medicinal plant industry, therefore, plays a critical role in empowering
large numbers of people. The traditional health sector is an important
segment of the Zimbabwean society in another way. It is estimated that around
4,000 tons of plant material with a value of Z$150m is used annually for
medical purposes.
But the country is slowly losing some of these valuable
medicinal plants and medical knowledge.
Besides the destruction of forests our traditional healers have been
victims of exploitation of their knowledge and medicines since the beginning
of this century. Exploitation of the knowledge and medicines of traditional
healers takes various forms. Many
academics interview traditional healers and publish the results of such
interviews without acknowledging the source of much of the information. Some
modern medical scientists also interview and even observe traditional healers
at work and then pass on the results of their investigations to established
pharmaceutical companies. Traditional healers are also aware that many agents
of foreign governments, pharmaceutical companies and research organizations
have been coming into the country to collect specimens from traditional
healers which they screen for specified biological activity at home then
isolate active compounds and apply for patents for these active compounds.
Traditional healers do not receive any form of compensation although a few
are known to have agreed to sell off their knowledge and resources for a few
hundred dollars. Thus, many medical scientists here and abroad seek access to
our traditional knowledge for the primary purpose of developing more
profitable products. Once healers share this information, they lose control
over that knowledge. Moreover, if the material is eventually patented,
monopoly patents can legally restrict access to this material.
The long-term
consequences of the present trend are clear, as listed below:
a.)
Thousands of traditional healers will
loose their major source of income, they will become unemployed,
b.)
Many medicinal plant traders will be
squeezed out of this indigenous market,
c.)
Many households will loose access to
their basic consumer good,
d.)
Biodiversity and health care will be
negatively impacted,
e.)
The declining supply of indigenous
medicinal plants will generate significant economic losses to the country.
Paper read at: National
Workshop on the Development of Sui-Generis Legislation on Intellectual
Property Rights (IPR) - Patents for Zimbabwe, Kadoma Ranch Motel Conference
Centre, 6-10 September, 1998
|
|
BOX 3. Benefit sharing Model: The case of
endod.
In Ethiopia, the berries of the African
soapberry (Phytolaccadodecandra) are used to make a natural soap. In 1964, an
Ethiopian researcher found that, in rivers where the women used endom (the
indigenous name for the soap) to wash their clothes, the zebra mussel (Biomphalaria)
seldom occurred. Apparently, endod was capable of killing the mussel. Since
the zebra mussel can act as a host to the parasite causing the human disease
bilharzia, the molluscicidal effect of endod was extremely useful to
indigenous Ethiopian communities.
Endod can be produced without highly
sophisticated technologies. The soapberry must be harvested- while still
unripe, dried in the shade and then ground to powder. About 300 million
people worldwide suffer from bilharzia, so a cheap alternative to synthetic
molluscicides seemed very attractive. The only synthetic product available
with similar toxicity and degradability characteristics was about 50 times as
expensive. However, the chemical industry did not show much interest in
producing endod. A product that can be produced that easily is not
commercially attractive to them, according to one of the researchers
involved. Obtaining funding for public-sector research and development also
proved difficult: donor agencies such as the World Health Organization (WHO)
target the bulk of their funds to research on AIDS and malaria.
In the end, a research
group at the University of Toledo, in the USA, picked up the research and
began investigating whether endod could be used to remove the zebra mussel
from the pipes of hydroelectric power plants. The University has now been
granted a United States patent on the use of endod. To get the patent, it
conducted one day of experimentation, then spent four months on legal and
scientific work to verify the initial evidence. Opponents to the claim argue
that the real work was done by Ethiopian scientists and, above all, by poor
Ethiopian communities. (Cited by Bunders et al (1996))
|
Source: M.S. SWAMINATHAN
Research Foundation CHENNAI, 1998
VI. REFERENCES
-
Cunningham, A.B. 1993. African Medicinal Plants: setting priorities at the interface between
conservation and primary health care.
Working paper 1. UNESCO, Paris.
-
Dagne,
D. 1998. Baseline chemical studies that aid in the development of essential oil
and
medicinal plant industry in Africa, Department of Chemistry, Addis Ababa
University, Addis
Ababa, Ethiopia
-
LeBeau,
D, 1998. Urban patients' utilisation of traditional medicine: upholding culture
and
Tradition, University of
Namibia, Sociology Department Windhoek, Namibia.
-
Marshall, N.T., 1998. Searching for a Cure: Conservation of Medicinal Wildlife Resources
in East and Southern Africa. TRAFFIC International.
-
Nshimo C. 1888. Utilization and conservation
of medicinal plants in Africa, Faculty
of Pharmacy, Muhimbili University College of Health Sciences, Dar es Salaam,
Tanzania.
-
Myles Mander,
1998. The marketing of indigenous medicinal plants in south Africa: a case
study
in Kwazulu-Natal, Institute of Natural
Resources, Natural Resource Management Programme,
South Africa.
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Wambebe C, 1998. Development and production of standardised
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