Okonogi Siriporn, Kaewpinta Adchareeya, Junmahasathien Taepin, Yotsawimonwat Songwut
Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University.
Research Center of Pharmaceutical Nanotechnology, Chiang Mai University.
Drug Discov Ther. 2018;12(4):206-213. doi: 10.5582/ddt.2018.01041.
The effects of variety and modification of rice on its antioxidant and anti-inflammatory activities were investigated. White rice varieties; Jasmine (JM) and Saohai (SH), and pigmented rice varieties; Doisket (DS) and Homnil (HN) were used. The modified rice samples were obtained from chemical modification using etherification reaction. The activities of the modified rice samples were compared with the ethanol extracts of the raw rice at the same rice concentration. Antioxidant activity was measured by the free radical scavenging activity tests and ferric reducing power assay. Results indicated that the ethanol extracts of raw rice had higher antioxidant activity than the modified rice. Among the raw rice tested, the pigmented rice showed higher antioxidant activity than white rice. Trolox equivalent antioxidant capacity values from free radical scavenging activity test were revealed that 50% ethanol extracts of HN and DS possessed the highest antioxidant activity. Ferric reducing power assay showed that 50% ethanol extracts of DS had the highest antioxidant activity. The anti-inflammatory activity was evaluated in vitro using a lipopolysaccharide-stimulated RAW264.7 macrophage cell model with enzyme-linked immunosorbent assay. Absolute ethanol extracts of HN reduced interleukin-6 secretion whereas that of DS suppressed interleukin-6 and tumor necrosis factor -α secretion. These results indicate that variety of rice, chemical modification, and extracting solvent were the factors that play an important role on antioxidant and anti-inflammatory activity. This study supports the potential use of the pigmented rice, especially DS, as a promising choice of a natural source because of its antioxidant and anti-inflammatory activities.
研究了水稻品种及其改性对其抗氧化和抗炎活性的影响。使用了白米品种茉莉香米（JM）和泰引9号（SH），以及有色米品种紫糯稻（DS）和Homnil（HN）。改性水稻样品通过醚化反应进行化学改性获得。在相同水稻浓度下，将改性水稻样品的活性与原稻的乙醇提取物进行比较。通过自由基清除活性测试和铁还原能力测定来测量抗氧化活性。结果表明，原稻的乙醇提取物比改性水稻具有更高的抗氧化活性。在所测试的原稻中，有色米比白米表现出更高的抗氧化活性。自由基清除活性测试的Trolox当量抗氧化能力值表明，HN和DS的50%乙醇提取物具有最高的抗氧化活性。铁还原能力测定表明，DS的50%乙醇提取物具有最高的抗氧化活性。使用脂多糖刺激的RAW264.7巨噬细胞模型通过酶联免疫吸附测定法在体外评估抗炎活性。HN的无水乙醇提取物减少白细胞介素-6的分泌，而DS的无水乙醇提取物抑制白细胞介素-6和肿瘤坏死因子-α的分泌。这些结果表明，水稻品种、化学改性和提取溶剂是对抗氧化和抗炎活性起重要作用的因素。这项研究支持将有色米，特别是DS，作为一种有前景的天然来源进行潜在应用，因为它具有抗氧化和抗炎活性。
