DNA damage inhibitory effect and phytochemicals of fermented red brown rice extract

Abstract

ObjectiveTo determine the polyphenol compounds (phenolic and flavonoid compounds), antioxidant activity [1,1-diphenylpicryl-2-picrylhydrazyl (DPPH) radical scavenging activity] and DNA damage inhibitory effect of fermented local red brown rice. MethodsDNA nicking assay was employed to determine the antioxidant activity of the fermented rice extract. Phytochemical screening was completed using standard methods and DPPH radical assays were used to confirm the antioxidant properties of the extracts. ResultsAfter four days of fermentation, fermented red brown rice had more polyphenol compounds compared to unfermented counterpart. Fermented red brown rice showed greater antioxidant properties with EC50 value of DPPH radical scavenging of 43.00 mg extract/mL or 8 mg quercetin equivalent antioxidant activity. In addition, fermented rice extract showed DNA damage inhibitory effect to a certain extent. It protected DNA from reactive oxygen species; however, at high concentration it might induce reductive damage to DNA, whereas, unfermented red brown rice showed weak DNA damage inhibitory effect. ConclusionsFermented red brown rice could protect DNA from oxidative damage but might induce reductive damage to DNA at high concentrations.