AN ANTIPLASMODIAL ACTIVITY OF LEAVES EXTRACTS OF CASSIA OBTUSIFOLIA AND HYPTIS SUAVEOLENS FROM GHANA

A number of the population in developing countries use herbs and herbal products to treat various diseases including malaria. However, most of them have not been evaluated for their efficacy and toxicity and their use is not standardized in some instances. Poly-herbal extracts may yield better treatment outcomes compared to extracts from a single plant due to the combined effects of bioactive compounds from the multiple sources. Cassia obtusifolia and Hyptis suaveolens are two plants commonly used in herbal preparations for treating malaria in Ghana. This study was to investigate Plasmodium falciparum asexual growth inhibitory activities of the individual and combined leaf extracts of the two plants. Leaves of the C. obtusifolia and H. suaveolens were extracted separately with methanol, ethanol and water. The six extracts, as well as in combination were evaluated in a dose-dependent manner for their antiplasmodial activities against the chloroquine-sensitive Plasmodium falciparum 3D7. Aqueous extract of C. obtusifolia, including the mixture of the two plants were highly active with mean IC₅₀ less than 4.0 µg/mL. Similarly, methanol extract of H. suaveolens and the mixture also had IC₅₀ below 4 µg/mL. Ethanol extracts of the mixture was correspondingly active with IC₅₀ less than 4.0 µg/ml. All the combined extracts inhibited parasite growth above 80% at concentration of 100.00 µg/mL. Our results showed good antiplasmodial activity of the two plants comparable to the standard drug, artesunate, and hence provides the basis for their continuous use as antimalarial therapy in Ghana, possibly in their combined form.