Biological screening of Viola betonicifolia Smith whole plant

Abstract

Crude methanolic extract as well as subsequent solvent fractions of Viola betonicifolia (VB) whole plant were tested for various in-vitro biological activities, including nematicidal, antioxidant, larvecidal, phytotoxic and cytotoxic. All extracts were also tested for their total flavonoid and phenolic contents. A dose dependent effect was observed against both nematodes. Ethyl acetate fraction was highly effective against Meloidogyne incognita , followed by chloroform and methanolic extract while the highest mortality of Meloidogyne javanica was observed against ethyl acetate followed by chloroform and methanolic extract with 45, 43 and 31% mortality, respectively. The antioxidant activity was tested using 1, 1-diphenyl 1-2-picryl-hydrazyl (DPPH) scavenging and reducing power assay for all extracts. The chloroform fraction showed highly significant antioxidant activity followed by ethyl acetate and methanolic extract. The maximum larvecidal effect against Aedes aegypti was observed for chloroform fraction followed by ethyl acetate fraction. In case of phytotoxic activity, butanol fraction was most effective followed by ethyl acetate fraction. Significant results were found by aqueous fraction with LC 50 46 µg/ml and chloroform with LC 50 56 µg/m against brine shrimp. Phytochemical studies indicated that ethyl acetate fraction was rich of flavonoid and phenolic contents followed by chloroform and methanolic extract. It was concluded that the ethyl acetate and chloroform fractions are the most significant sources of antihelmintic, antioxidant, larvecidal, phytotoxic and cytotoxic compounds.