Ethanolic Extract of Black Rice'Sembada Hitam' Bran Protects the Cytotoxic Effect of H2O2 on NIH3T3 Cells.

Oxidative stress which is triggered by endogenous and exogenous stressors such as oxygen metabolism in mitochondria, radiation, drugs, and pollutants, negatively affect biological systems. Various pathophysiological conditions and the life span of organisms were affected by such condition. Secondary metabolites found in natural ingredients such as black rice have high antioxidant activity that can prevent oxidative stress. This study aimed to examine potency of the ethanolic extract of black rice (Oryza sativa L. `Sembada Hitam') bran to protects H2O2-induced NIH3T3 cells. This research was focused to evaluate the potency of black rice bran's (BRB's) extract on cytotoxicity, apoptosis, and cell growth due to H2O2 induction. This study used a combination of H2O2 exposure at various concentrations (50, 100, 150, 200, and 300 pM) and BRB's extract at various concentrations (7.81; 15.63; 31.25; 62.5; 125; 250; 500; and 1000 pg/mL). Our results showed that BRB's extract at the concentration of 7.81 to 1000 pg/mL maintained NIH3T3 cells viability above 80% against 50 and 100 pM H2O2 exposure for 24 hours. These were in line with the apoptosis test results, which showed that the BRB's extract suppressed apoptosis, especially the combination of BRB and H2O2 exposure at 62.5 pg/mL and 100 pM; 62.5 pg/ mL and 200 pM, as well as 250 pg/mL and 100 pM, respectively. Moreover, the H2O2-induced NIH3T3 cells' growth was maintained up to the fifth day under the BRB's extract treatment. The result proved that pretreatment of BRB's extract at the concentration of 62.5 pg/mL is highly effective as an anti-apoptotic and increases cell proliferation up to the fifth day on H2O2- induced NIH3T3 cells. Collecting all the results together, we suggested that BRB's extract have a protective effect by maintaining NIH3T3 cell viability against H2O2 induction.