This study investigated the antioxidant and anti-inflammatory activities of -oryzanol rich extracts from\r\nThai glutinous purple rice bran. Five purple rice bran samples, PAH E-KAW, GAM PEUAK, NIAW DAM,\r\nGAM THOR and GAM BOUNG were obtained from local glutinous cultivars in Northern Thailand. The -\r\noryzanol rich extracts were prepared by soxhlet extraction and semi-purified by column\r\nchromatography. The extracts contained -oryzanol in the range of 1.23 to 9.14% w/w. The extracts\r\ncontaining more than 5% w/w of -oryzanol (PAH E-KAW, GAM THOR and GAM BOUNG) were selected\r\nfor investigation of antioxidant and anti-inflammatory activities; and first standardized by adding the\r\nequivalent amount of each extract to give 10% w/v -oryzanol. All of extracts exerted moderate ABTS+\r\nand superoxide anion scavenging activity. GAM BOUNG exhibited the highest ABTS+ scavenging\r\nactivity with VCEAC value of 201.3 1.84 mg L-ascorbic acid/ gram extract, TEAC value of 267.2 2.96\r\nmg Trolox/ gram extract and QEAC value of 137.4 3.41 mg Quercetin/ gram extract followed by PAH EKAW\r\nand GAM THOR, respectively. GAM BOUNG also showed the highest activity on superoxide anion\r\nscavenging at IC50 = 12.56 0.13 g/ml followed by GAM THOR and PAH E-KAW. Furthermore, GAM\r\nBOUNG exhibited a strong inhibition effect on linoleic acid peroxidation (IC50 = 36.79 2.97 g/ml).\r\nAdditionally, all of the extracts showed a strong anti-inflammatory activity through inhibitory effect on\r\nnitric oxide (NO) production in combined LPS-IFN--activated RAW 264.7 murine macrophage cells.\r\nGAM BOUNG exhibited the highest inhibitory effects on NO production (IC50 = 29.32 2.21 g/ml),\r\nwithout exerting cytotoxicity followed by GAM THOR and PAH E-KAW. These results indicate that -\r\noryzanol rich extracts from Thai glutinous purple rice bran are acting as a lipophilic radical scavenger\r\nbetter than a hydrophilic radical scavenger. Moreover, these extracts exert a potent anti-inflammatory\r\nactivity.
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