Evaluation on antioxidative capacity, nephroprotective effect, and DNA damage protection of mixed low potassium vegetables and fruits juice powder in HEK-293 cells

Background: An imbalance between free radical production and antioxidant defenses is one of the multifactorial natures contributing to many disorders. One of them is chronic kidney disease (CKD). The development of novel diets to slow progression or reduces complication of CKD are highly needed. Therefore, the objective of this study was to evaluate the in vitro antioxidative capacity and nephroprotective effect of a product, mixed low potassium vegetables and fruits juice powder (MJP) in HEK-293 cells. Methods: The produced MJP was determined for phenolics and flavonoids content. The antioxidative capacity was examined by DPPH, FRAP and ABTS assay. The cell viability to MJP and hydrogen peroxide (H2O2)-treated were determined by MTT assay. The intracellular antioxidative capacity was determined by co-treatment of MJP and H2O2-induced HEK-293 cell damage including reactive oxygen species (ROS) production, intracellular enzymes activities, and DNA damage protection. Results: The MJP at the concentration of 5 and 10 mg/ml showed positive effects on H2O2-induced HEK-293 cells protection and significantly increased cell viability. The ROS production measured by 2',7'-dichlorodihydrofluorescein diacetate (DCF) were increased in the H2O2 treatment approximately 2 times but significantly decreased in the MJP treatment. The result of intracellular enzymatic antioxidant markers, including superoxide dismutase (SOD) and catalase (CAT) activities were increased while the Malonaldehyde (MDA) level was attenuated in the co-treatment of MJP and H2O2-induced HEK293 cells compared with only H2O2-inducing. In the examination of the morphological change due to oxidative stress exhibited less nuclei fragment in the cell of MJP treatment. In addition, the isolated DNA was protected by MJP application. Conclusion: The produced MJP contains bioactive phenolic and flavonoid compounds. MJP possesses potential antioxidative capacity through the reducing H2O2-induced HEK-293 cells damage and increasing the intracellular antioxidant enzymes. In addition, the nephroprotective effects of MJP related to the antioxidant enzymes was involved in the free radical scavenging. Therefore, MJP could be a functional drink for individual limiting potassium and liquid uptake.