LAUSR

Abstract Cadmium (Cd) has a remarkable property of generating oxidative stress. It upregulates the level of reactive oxygen species, which generates damage to lipids, proteins, and DNA The level of oxidative stress by Cd is observed by inhibitory effects of antioxidant enzymes such as catalase, superoxide dismutase, glutathione reductase, and glutathione peroxidase. Piperine is one of the plant-derived alkaloids isolated from Piper nigrum and Piper longum. It diminishes the level of oxidative damage by quenching the free radicals and reactive oxygen species and inhibiting the lipid peroxidation. It is well known to induce stress proteins, including metallothionein (MT), a metal-binding protein and heat shock protein (HSP70). In the present work, antioxidative effects of piperine have been studied against Cd-induced oxidative stress. We observed its ameliorative effects using various biomarkers, such as comet and lipid peroxidation (LPA) assays in cultured human peripheral blood lymphocytes from healthy individuals. Piperine at 35 and 50 µM concentrations significantly reduces the tail moment and peroxidation of lipids. We also explored the relationship of MT2A gene polymorphism on oxidative and antioxidative effects of Cd and piperine, respectively. At selected concentration, we observed a decrease in the mean value of tail moment and lipid peroxidation level. However, the overall effect was statistically nonsignificant (p > .05).