Antiplasmodial, antioxidant, antipyretic and cyto-toxic activities of hydroethanolic extract of Phyllanthus niruri (Linn), Sida acuta (Burm) and their combination

Abstract

The resistance of Plasmodium, to medications is hindering malaria eradication efforts. As a reason, the search for treatments has become  crucial. Therefore, this study aimed to explore the effectiveness of a malaria treatment recipe containing extracts from Phyllanthus niruri  Linn and Sida acuta Burm. The study evaluated antioxidant activity by phosphomolybdate reduction and the FRAP method; antimalarial  activity was assessed on Plasmodium falciparum field isolates in vitro; antipyretic activity using yeast induced hyperthermia and measured cytotoxicity with the MTS (3-(4,5-dimethylthiazol-2-yl) -5- (3- carboxymethoxyphenyl) -2- (4- sulfophenyl)-2H-tetrazolium) assay.  The P. niruri extract showed the best antioxidant activity with concentrations of 0.09 ± 0.00 mg AAE/g extract using the  phosphomolybdate reduction method and 267.17 ± 25.66 µmol Eq Fe2+/mg extract using the FRAP (Ferric Reducing Antioxidant Power)  method respectively. The different extracts and their combination demonstrated effects on P. falciparum fields with IC₅₀ (Concentration of the substance that inhibited 50% of parasites) values ranging between 0.19 to 2.68 µg/ml (IC₅₀ < 5 µg/mL). Additionally antipyretic  activity results indicated that the combined extracts had effects compared to paracetamol a common reference drug. The results, from  the cytotoxicity tests indicated that both extracts had a CC₅₀ (The cytotoxic concentration for 50%) above 100 µg/mL. It was found that all  plant extracts are non-toxic and when combined they exhibited intriguing biological effects.