Ethnobotany, Bioactivity and Variation Studies of Traditional Ghanaian Anti-Malarial Plants

Abstract

An investigation on traditional plants used in the treatment of malaria in Ghana was conducted. The study involved a collection of information from an indigenous group of people living in the Wechiau Community Hippopotamus Sanctuary Ghana about their knowledge on plant species used for the treatment of malaria. It also involved a study of the bioactivity and variations within selected plant species in the sanctuary. The investigation on the indigenous uses involved ethnobotanical interviews and field studies. Forty-one species of plants in 19 families were mentioned as used for the treatment of malaria in the sanctuary. Eight of the species of plants. namely. Afrraegle paniculata, Haemastostaphis bateri, indigofera pulchra, monathotaxis sp., Ozoroa insignis. strychnos innocua,strychnos spmosa and Xeroderris stuhlmanuii have not been previously investigated for their anti·malarial uses. The efficacy of four anti-malarial species. namely, Cassia sieberiana, Haematostaphis barteri, Mitragyna mermis and Pseudocedrela kotschyiand was determined by testing their extracts against several organisms including Plasmodium,bacteria, fungi and an insect pest. The methods of the bioassays included mic:rodilution technique for in vitro antiplasmodial assay. TLC agar-overlay diffusion for microbial bioassay and a binary choice assay for insect anti-feedant testing. The extracts were moderately active against Plasmodium and varied in their activity against the test organisms. From the stem and root barks of Haematostaphis barteri three Stilbene compounds were isolated for the first time from a member of the family Anacardiaceae.The identification of stilbenes was made through the use of NMR and APCI-MS expenmeruation. Variation study using data from a range of characters including morpholgy, anatomy of barks, ecology. distribution, Comparative phytochemistry and molecular (AFPL markers) were conducted to understand infraspecific taxonomy of tbe four species of plants and for their conservation in the sanctuary. Data obtained from the morpnomemc measurements, maceration, field ecologica1 methods, specimen computerisation, phytochemical methods such as HPLC and LC-MS and AFLP methodologjes were used for the variations analysis. The variations in the selected species were largely due to morphological and chemical variability. The variations in the species of plants were found to be due to plasticity of environmental factors and that the taxonomies of the four species are stable in the sanctuary