Antioxidative Properties and Cytotoxic Activity against Colon Cancer Cell WiDr of Rhizopus oryzae and Rhizopus Oligosporus-Fermented Black Rice Bran Extract.

Black rice bran (BRB) was reported to have several bioactive compounds which can potentially as antioxidant and reduce the colon cancer incidence. Fermentation was reported to be able to increase bioavailability through deliberating the bioactive compounds from the cellular matrix. The aim of this study was to improve the bioavailability of BRB bioactive compounds which offer beneficial health properties as antiproliferative against colon cancer cell WiDr and confer antioxidant activity by fermentation. The study was conducted in 4 groups of different condition: non-fermented, the use of R. oryzae, R. oligosporus and combination of R. oryzae + R. oligosporus for fermentation starter, respectively. BRB fermentation was conducted in 72 and 96 hours. Each of fermented BRB (FBRB) was then extracted by using 70 % ethanol and methanol, respectively. Extracts derived from FBRB were evaluated for their availability of total phenolic content (TPC) by using total phenolic analysis, antioxidative activity by using DPPH and FRAP assay, and antiproliferative properties toward colon cancer WiDr by using MTT assay. The result of the se studies showed that an increased amount of TPC of the ethanolic and methanolic extract of FBRB when compared to non-fermented BRB (NFBRB).Consequently, DPPH and FRAP antioxidant capacity of FBRB was higher than that of NFBRB. The antiproliferative activity of FBRB against colon cancer cells, WiDr, was also shown to be higher activity than that of NFBRB (As shown on IC50 extract). This results indicated that BRB could optimally increase its antioxidant and antiproliferative activity by fermentation. [ABSTRACT FROM AUTHOR]