Rice Bran Extract

Arab, F., I. Alemzadeh, et al. Scientia iranica, 2011, 18(6), 1402-1406.

Rice bran contains abundant natural antioxidants which enable its use as a compound to neutralize free radicals. Researchers tested antioxidant properties in extracts from rice bran varieties Fajr and Tarem using methanol, ethanol, and ethyl acetate as solvents.
· Evaluation Methods
The order of antioxidant activity was evaluated by measuring the total phenolic content, antioxidant activity in the linoleic acid system, reducing power, and DPPH radical scavenging ability.
· Evaluation Results
At the concentration tested (50 mg/ml), the overall trend of DPPH scavenging activity was MeOH extract > EtOH extract > EtOAc extract (p<0.05). In addition, the reducing power of rice bran extracts increased with increasing concentration. The study also revealed the antioxidant effect of rice bran extracts through linoleic acid peroxidation.
The methanol extract from Fajr rice bran contained 3.31 mg gallic acid equivalents per gram of bran and showed 93.91% DPPH radical scavenging activity at 50 mg/ml with a linoleic acid peroxidation inhibition rate of 68.01% demonstrating its reducing capabilities. Based on these findings the methanol extract derived from rice bran demonstrates potential as a natural antioxidant.

Ha, Su Jeong, et al. Bioscience, Biotechnology, and Biochemistry, 2018, 82(2), 320-328.

The research examined how rice bran supplement (RBS) consumption might protect against UVB light-induced aging effects in vivo. Research revealed that RBS could serve as an active bioactive compound in nutraceuticals which works to reduce wrinkle development and water loss through the suppression of COX-2 and MMP-13 expression.
· Evaluation Methods
The study used the SKH-1 hairless mouse model to assess the RBS impact on UVB-induced photoaging by measuring COX-2 and MMP-13 expression levels along with MAPK pathway activity and epidermal thickening.
· Evaluation Results
The intake of RBS minimized the formation of wrinkles caused by UVB exposure while simultaneously stopping water loss and epidermal thickening in mouse skin. Studies using Western blot and immunohistochemistry demonstrated that serial UVB exposure led to higher levels of matrix metalloproteinase-13 (MMP-13) and cyclooxygenase-2 (COX-2) expression. RBS consumption led to inhibition of MMP-13 expression and COX-2 expression together with MAPK signaling pathway activation suppression.