Anti-oxidant and anti-inflammatory effects of rice bran and green tea fermentation mixture on lipopolysaccharideinduced RAW 264.7 macrophages
Purpose: To investigate the anti-inflammatory and anti-oxidant properties of an enzyme bath of Oryza sativa (rice bran) and Camellia sinensis O. Kuntz (green tea) fermented with Bacillus subtilis (OCB).
Methods: The anti-oxidant effects of OCB were assessed by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay and flow cytometry. The anti-inflammatory effects of OCB were assessed by a nitric oxide (NO) assay. Enzyme-linked immunosorbent assay and real-time polymerase chain reaction were used to quantify expression of pro-inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The major compounds of OCB were identified using high performance liquid chromatography (HPLC) analysis.
Results: OCB had no cytotoxic effect on LPS-stimulated macrophages or peripheral blood mononuclear cells up to 1 mg/mL. OCB displayed anti-oxidant effects comparable to those of ascorbic acid and reduced reactive oxygen species (ROS) levels in target cells. OCB treatment of LPSstimulated mavrophages decreased nitric oxide (NO), NO synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) and key pro-inflammatory cytokine expressions, suggesting that OCB acts as an anti-oxidant and anti-inflammatory agent by reducing ROS levels and inhibiting pro-inflammatory mediators. The main effector compounds in OCB were epicatechin gallate, cathechin, synigrin acid, epicathechin, epigallocatechin gallate, rutin, and isoquercetin, which are known anti-oxidants.
Conclusion: OCB fermentation product may be used as synergistic adjuvant therapy for inflammatory diseases.
Keywords: Rice bran, Green tea, Bacillus subtilis, Enzyme bath, Anti-oxidant, Anti-inflammation