ABSTRACT
Aims: The present study was carried on the stem bark of Cassia arereh Del. Different extracts were prepared and were assessed for their in vitro larvicidal, antiplasmodial and cytotoxicity properties. Methodology: Larvicidal activity of the methanol extract was evaluated against 3rd instar larvae of Culex quinquefasciatus using method recommended by World Health Organization. The antimalarial activity of chloroform, ethyl acetate, methanol and aqueous extracts was assessed on the chloroquine-resistant strain W2 strain of Plasmodium falciparum by flow cytometry. Cytoxicity effect was assessed on two human cell lines K562S (by flow cytometry) and HepG2 (by MTT assay). Results: The larvicidal activities of different concentrations of C. arereh stem bark methanolic extract after 24 h of incubation revealed that the 1.0 g/L concentration gave the highest mortality (40.2%). lethal concentrations that killed 25% (LC25), 50% (LC50), 90% (LC90) and 95% (LC95) of larvae in 24 h were 4235, 8230, 16007, 29325 and 40680 ppm. The best antimalarial activities were detected in the chloroform extract with IC50 > 12.5 μg/ mL and cytotoxicity effect with IC50 > 12.5 μg/ mL on both K562S and HepG2 cell lines indicative of promising security index. Phytochemical screening indicated the presence of anthraquinones, flavanoids, terpenes, steroles and tannins. Conclusion: This result indicates that C. arereh stem bark could be a good source of bioactive ingredients.