Bioactive components and anti-photoaging activity of Aspergillus oryzae fermented rice bran extract

Rice bran, as the main byproduct of rice processing, has a promising industrial application prospect due to its various bioactive components. In this study, Aspergillus oryzae was applied for solid-state fermentation of rice bran to prepare an extract with potential anti-photoaging properties. The differential compounds between unfermented and fermented rice bran extracts were analyzed by Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (LCMS-QTOF) and the anti-photoaging activity was evaluated based on a model of UVB-induced human immortalized keratinocytes (HaCaT) photoaging. A total of 448 different bioactive components, divided into 17 categories, were identified. The content of sinapic acid, tricin, 3-coumaric acid, vanillic acid, ferulic acid and salicylic acid were significantly increased by 23.62, 19.14, 21.07, 14.27, 16.39 and 2.07 folds, respectively, after fermentation. Moreover, the fermented rice bran extract can effectively enhance the activity of antioxidant enzymes and decrease the levels of malondialdehyde (MDA), matrix metalloproteinase-1 (MMP-1) and interleukin-6 (IL-6) in UVB-induced photoaged HaCaT cells.