Pro-oxidative effects of green tea polyphenols in Brugia malayi microfilariae: A mechanistic study

Abstract

The study investigated the redox mechanism of green tea extract's anti-microfilarial activity and therapeutic safety against Brugia malayi microfilariae and Human peripheral blood mononuclear cells (PBMCs), while measuring polyphenol content. One variant of green tea extract, showing higher polyphenols content and lower IC₅₀/IC₁₀₀ value, was selected for mechanistic study. Oxidative stress was assessed by estimation of reduced glutathione and protein carbonylation. The reversal of anti-filarial effect was assessed by the pre-treatment of green tea treated microfilariae with reduced glutathione (GSH). AO-EB staining, MTT assay, cytochrome c estimation and PARP assay were performed for detecting the apoptotic mechanism. Green tea extract's anti-microfilarial activity was reduced by polyphenol depletion, leading to increased protein carbonylation and decreased GSH levels in treated microfilariae compared to untreated control. Green tea extract, rich in polyphenols, induces oxidative stress and apoptosis through mitochondrial pathway involvement, reversing anti-microfilarial effects and promoting MTT reduction and cytochrome c release.