In vitro free radicals scavenging activity and antioxidant capacity of solid-state fermented wheat bran and its potential modulation of antioxidative molecular targets in chicken PBMC

ABSTRACT The purpose of this study was to demonstrate the in vitro free radical scavenging activity and antioxidant capacity in solid-state fermented wheat bran and its potential modulation of antioxidative molecular targets in chicken peripheral blood mononuclear cells (PBMC). After solid-state fermentation of wheat bran by white rot fungi for 12 d, the scavenging action of the fermented wheat bran extracts was 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and the free radicals increased significantly, approximately 1.5-fold. Trolox equivalent antioxidant capacity of 1 mg/mL fermented wheat bran extracts was increased from 100 to 150 mM trolox antioxidant capacity after 12 d of fermentation. Moreover, the extracts exhibited 50% of the chelating capacity observed for ferrous iron (Fe2+) after fermenting for 12 d. In vitro, and under the stimulus of fermented wheat bran, the antioxidant gene expression (GST, HO-1, Nrf2, and GCLC genes) of PBMC was more than double that of the PBS, ascorbic acid, and unfermented wheat bran. The expression of fermented wheat bran was the lowest for the NOX1 and ROMO1 genes. Solid-state wheat bran fermented by white rot fungi can increase the scavenging action of DPPH, the trolox equivalent antioxidant capacity, and the chelating capacity of ferrous iron; in addition, in vitro, it can regulate the expression of antioxidant molecular targets in chicken PBMC.

摘要：本研究旨在探究白腐真菌固态发酵麦麸的体外自由基清除活性与抗氧化能力，及其对鸡外周血单个核细胞（peripheral blood mononuclear cells, PBMC）抗氧化分子靶点的潜在调控作用。经白腐真菌对麦麸进行12天固态发酵后，发酵麦麸提取物对1,1-二苯基-2-苦基肼基（1,1-diphenyl-2-picrylhydrazyl, DPPH）自由基的清除活性显著增强，增幅约达1.5倍；1 mg/mL的发酵麦麸提取物的Trolox当量抗氧化能力在发酵12天后从100 mM提升至150 mM。此外，发酵12天后的提取物对亚铁离子（Fe2+）的螯合能力达到参照体系的50%。体外实验中，在发酵麦麸提取物的刺激下，鸡PBMC的抗氧化基因（谷胱甘肽S-转移酶（GST）、血红素氧合酶-1（HO-1）、核因子E2相关因子2（Nrf2）以及谷氨酸-半胱氨酸连接酶催化亚基（GCLC））的表达量分别为磷酸盐缓冲液（phosphate buffered saline, PBS）、抗坏血酸（ascorbic acid）及未发酵麦麸处理组的2倍以上；而发酵麦麸处理组中，烟酰胺腺嘌呤二核苷酸磷酸氧化酶1（NOX1）与活性氧调节因子1（ROMO1）的基因表达量最低。综上，经白腐真菌固态发酵的麦麸可提升其提取物对DPPH自由基的清除能力、Trolox当量抗氧化能力以及对亚铁离子的螯合能力，且该发酵产物在体外可调控鸡PBMC的抗氧化分子靶点基因表达。