Crude proteins from pigeon pea (Cajanus cajan (L.) Millsp) possess potent SOD-like activity and genoprotective effect against H2O2 in TK6 cells

Abstract

In the present study, we reported new investigations on antioxidant potential of biological proteins from pigeon pea (Cajanus cajan (L.) Millsp) seeds. The crude pigeon pea proteins (PPP) were obtained by extraction with PBS, NaCl and water. The PPP extracts were precipitated by ammonium sulfate [(NH4)2SO4] in various percentage. All fractions were investigated in their potential antioxidant activity of both enzymatic antioxidant-like activity and anti-oxidative cellular damage in TK6 human lymphoblasts. The protective effect of membrane damage was investigated by employing mitochondrial dehydrogenase (MDH) and lactate dehydrogenase (LDH) activity assays and the anti-oxidative DNA damage was assed using comet assay. Results revealed a potent superoxide dismutase (SOD) like activity in three protein fractions including P-II, N-II, and W-III. Their molecular weight distributions were located mainly in a range of 6 to 66 kDa. The highest inhibitory effect on mitochondrial and cell membrane damage was found in N-II fraction. Interestingly, the results from comet assay demonstrated the anti-oxidative DNA damage in H2O2-induced TK6 cells. This activity was indicated by a significant reduction in tail length (TL) damage parameter. According to our results obtained in this study, we conclude that proteins isolated from pigeon pea seeds possess anti-oxidative effects on H2O2-induced cellular damage. Key words: Pigeon pea, antioxidant-like activity, anti-oxidative activity, H2O2, comet assay.