Médecine alternative et intégrative

In Vitro Sensitivity of Plasmodium falciparum Field Isolates to Methanolic and Aqueous Extracts of Cassia alata (Fabaceae)

Abstract

Wabo Poné Josué, Noumedem Anangmo Christelle Nadia, Komtangi Marie Claire, Yondo Jeannette and Mpoame Mbida

Objective: The aim of this study was to evaluate the in vitro activity of aqueous and methanolic extracts of Cassia alata leaves on the development of Plasmodium falciparum field isolates. Method: The Trager and Jensen method with slight modifications was used. For the culture, RPMI 1640 and Albumax were used to replace human serum. The extracts as well as the reference drug (chloroquine) were diluted using RPMI medium. The P. falciparum field isolates were incubated with 8 concentrations ranging from 128 to 1 μg/ml in a 96-well microplate and incubated for 48 h in a candle jar. RPMI and 1% DMSO were used as negative controls. Result: The extraction yields of C. alata were 7.96 and 13.23% for aqueous and methanolic extracts respectively. RPMI and DMSO didn’t have any harmful effect on the growth of P. falciparum. On the other hand, in the wells treated with extracts of C. alata leaves, inhibition of P. falciparum growth was registered with increasing concentrations of extracts. The inhibitory effect of the methanolic extract was stronger and we obtained the maximum mean inhibition rate of 100 ± 0.00% and 99.87 ± 0.62% at the concentrations 128 and 64 μg/ml respectively. As for the aqueous extract, it yielded a mean inhibitory rate of 99.2 ± 0.76% at the concentration of 128 μg/ml. Given the IC50 obtained that is 0.48 ± 0.02; 0.67 ± 0.11 and 0.77 ± 0.08 μg/ml for methanolic extract, aqueous extract and chloroquine respectively. The extracts of C. alata may be classified as active. This activity may be due to the presence of terpenes and tannins in the extracts.