According to the World Health Organization (WHO), 80% of the world's population uses medicinal plants in the treatment of diseases and, in African countries, this rate is much higher. In recent years, however, medicinal plants have represented a primary health source for the pharmaceutical industry. No less than 400 compounds derived from plants are currently used in the preparation of drugs, such as vincristine and vinblastine used in the treatment of cancer. Nigerians still depend largely on crude herbal remedies or traditional medicine. They also use wild plants for cosmetics and perfumery. Some of these herbal remedies have been observed to be effective in certain skin diseases.
The data were obtained from history questionnaires completed by patients at the Dermatology Clinic, Lagos State University Teaching Hospital (LASUTH), Ikeja, Lagos, Nigeria, and from oral interviews with vendors and prescribers of herbal preparations at major markets at Lagos and Ijebu-Ode in south-west Nigeria, between July 2004 and July 2006. Photographs of plants were taken at private residences at Lagos, Ibadan, and Ijebu-Ode in south-west Nigeria. A literature search was conducted on 38 of the plants. The data are presented in tabular form.
Sixty-five per cent of patients had applied some form of herbal remedy before attending our clinic. The reasons for consultation included relapses, unsustained relief, incomplete resolution, and post inflammatory hyperpigmentation. Lesions for which herbs were successfully applied included infantile eczema and seborrhoiec dermatitis, atopic eczema, impetigo, impetiginized eczema, tinea capitis, scabies, erythema multiforme, leg ulcers, localized vitiligo, and sexually transmitted diseases. Partial relief was achieved in dermatophytoses, ichthyosis, leprosy, and systemic lupus erythematosus (SLE). Some forms of alopecia, onychomycosis, and vitiligo, as well as allergic dermatoses, were not improved by herbal medicines. The preparation of the remedies was mostly by heating and boiling, infusion, and maceration. In most cases, mixtures of plants or other substances were used. The preparations were applied as poultices, ointments, baths, soaks and soaps, and oral fluids. The plants used included Adansonia digitata, Aframomum melegueta, Aloe species, Azadirachta indica, Cassia alata, Alstonia boonei, Ficus asperifolia, Cocos nucifera, Jatropha gossypyfolia, Ocimum gratissimum, Ricinus communis. A literature search on 38 of the plants used by herbal prescribers revealed the presence of established antimicrobial agents, immune modulating agents, antioxidants, other vitamins and minerals, volatile oils and emollients, and anti-inflammatory agents. Some of the plants may be contaminated by mycotoxins because of poor storage.
There appears to be clinical, scientific, and pharmacologic basis for the use of herbal preparations. Nigeria needs to provide effective coordination of the practice of herbal medicine to ensure safety, standardization, and preservation of the flora.