In vitro Antiplasmodial Actitvity of Aqueous and Ethanol Stem And Leaf Extracts of Senna Occidentalis (Coffee Senna)

Abstract

Development of resistance against the frontline anti-malarial drugs has created an alarming situation, which requires intensive drug recovery to develop new, more effective, affordable and accessible anti-malarial agents. Plants as Senna occidentalis produce a wide variety of phytochemical constituents, which are secondary metabolites and are used either directly or indirectly in the pharmaceutical industry. Phytochemical screening and antiplasmodial activity of the aqueous and ethanol extracts of S. occidentalis (L.) leaves and stems were studied in this work. The preliminary screening of the leaf extracts revealed the presence of alkaloids, saponins, cardiac glycosids, quinine, protein and amino acid, phenol, flavonoids and carbohydrate and showed absence of tannins. Likewise, stem extracts which shows absence of phenols in addition to tannins in the ethanol extract. These extracts were assayed at various concentration using double serial dilution (20mg/ml, 10mg/ml, 5mg/ml, 2.5mg/ml and 1.25mg/ml) for antiplasmodial effect after 24, 48 and 72hours respectively, and the activity of the extracts were obtained as percentage activity of the extracts after 72 hours of incubation period. The result of antiplasmodial activity revealed that both aqueous and ethanol stem and leaf extracts of the plant were effective against the malaria parasite. However, the aqueous stem extract showed greater activities than the ethanol extract. At extract concentration of 20mg/ml, both ethanol and aqueous extracts produced highest parasite clearance rate after 72 hours of incubation with percentage elimination of 77%. From these observations, S. occidentalis is likely to contain promising chemical compounds which can be utilized as an effective plant-based medicine for the treatment of malaria. Key words: Malaria, phytochemicals, antiplasmodial, parasite, aqueous, ethanol