In 1975 I began to be interested in the study of the active principles of African medicinal plants and searched for relevant literature. At the time I was particularly interested in receiving more information on West African plants as we were developing experimental work in collaboration with the Chemistry Department of the Nigerian University of Nsukka and I became aware of the great difficulty in finding fairly reliable documentation even on some of the best-known traditional herbal remedies.

Factors which may account for this are that the local uses were very numerous and often differed from one tribe, village or healer to another. Also, not only did superstition play an important part (often both magical purposes and empirical beliefs were attributed to the plants) but purgatives, diuretics and emetics were often used to chase the evil influences the people did not understand.

The patient work of some distinguished scholars working in the field in Africa provided an important contribution to our acquisition of knowledge on the traditional uses but only a few publications gave a more selective view on the subject. Among these one of the most relevant to me was the book of Dr Bep Oliver (Oliver-Bever), Medicinal Plants in Nigeria. She selected uses which were confirmed by the use of the same plants as cures by primitive populations in other parts of the world with similar climate, and also those which were likely to have real therapeutic value from a consideration of the then known chemical and pharmacological information.