Cameroonian medicinal plants: a bioactivity versus ethnobotanical survey and chemotaxonomic classification

Abstract

Background: In Cameroon herbs are traditionally used to meet health care needs and plans are on the way to integrate traditional medicine in the health care system, even though the plans have not been put into action yet. The country however has a rich biodiversity, with ~8,620 plant species, some of which are commonly used in the treatment of several microbial infections and a range of diseases (malaria, trypanosomiasis, leishmaniasis, diabetes and tuberculosis).

Methods: Our survey consisted in collecting published data from the literature sources, mainly from PhD theses in Cameroonian university libraries and also using the author queries in major natural product and medicinal chemistry journals. The collected data includes plant sources, uses of plant material in traditional medicine, plant families, region of collection of plant material, isolated metabolites and type (e.g. flavonoid, terpenoid, etc.), measured biological activities of isolated compounds, and any comments on significance of isolated metabolites on the chemotaxonomic classification of the plant species. This data was compiled on a excel sheet and analysed.

Results: In this study, a literature survey led to the collection of data on 2,700 secondary metabolites, which have been previously isolated or derived from Cameroonian medicinal plants. This represents distinct phytochemicals derived from 312 plant species belonging to 67 plant families. The plant species are investigated in terms of chemical composition with respect to the various plant families. A correlation between the known biological activities of isolated compounds and the ethnobotanical uses of the plants is also attempted. Insight into future direction for natural product search within the Cameroonian forest and Savanna is provided.

Conclusions: It can be verified that a phytochemical search of active secondary metabolites, which is inspired by knowledge from the ethnobotanical uses of medicinal plants could be very vital in a drug discovery program from plant-derived bioactive compounds.

Figure 1

Cameroon (in brown) and its surrounding neighbours.

Figure 2

Bar chart showing the distribution of isolated compounds by plant family. Family names are indicated by the first four letters, e.g., Apoc = Apocynaceae.

Figure 3

Pie chart showing the distribution by compound types.

Figure 4

Chemical structures of taxonomic markers.

Figure 5

Chemical structures of bioactive metabolites I. Compounds 24 to 52.

Figure 6

Chemical structures of bioactive metabolites II. Compounds 53 to 79, 82 and 93.

Figure 7

Chemical structures of bioactive metabolites III. Compounds 80, 81, and 83 to 106.

Figure 8

Chemical structures of bioactive metabolites IV. Compounds 107 to 119.