Down-regulation of GST and CAT gene expression by methanolic extract of Nigella sativa seed in human peripheral blood mononuclear cells

The anti-oxidant effect of Nigella sativa (NS) on human Peripheral Blood Mononuclear Cells (PBMCs) on a PHA (phytohemagglutinin) and a non-PHA stimulated proliferation were tested using SYBR Green based Real Time PCR analysis for antioxidant enzyme’s gene expression [glutathione-stransferase (GST) and catalase (CAT)]. Cells isolated from human PBMCs were treated with methanolic extract of NS for 48 h in two separate environments (PHA and non-PHA stimulated). The results obtained indicate that extracts from NS had down regulation effect. GST was down regulated to 1 and 1.5 fold after exposure to 2.5 µg/L NS extract for 48 h in PHA stimulated cells compared to respective controls whereas it decreased to 4 and 2 fold at dose of 5 µg/L in non-PHA stimulated cells compared to respective controls. Similarly, CAT was down regulated to 2 and 6 fold after exposure to 2.5 µg/L NS extract for 48 h whereas, it decreased to 4 and 2 fold at dose of 5 µg/L in PHA and non-PHA stimulated cells compared to respective controls. This in-vitro study reveals the effects of NS plant extract on GST and CAT gene expression in human PBMCs.