Kangwan Napapan, Kongkarnka Sarawut, Pintha Komsak, Saenjum Chalermpong, Suttajit Maitree
Division of Physiology, School of Medical Sciences, University of Phayao, Phayao 56000, Thailand.
Department of Pathology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Biomedicines. 2023 Jan 18;11(2):265. doi: 10.3390/biomedicines11020265.
Inflammatory bowel disease (IBD) has become a global concern. Proanthocyanidin-rich red rice extract (PRRE) has been shown to suppress the inflammatory response in cellular cultures. However, the anti-colitis effect of PRRE has never been investigated in animals. This study aimed to examine the protective effect of the PRRE against dextran sulfate sodium (DSS)-induced colitis in mice. Male mice were orally administrated with PRRE of 50, 250 and 500 mg/kg/day for 21 days. Acute colitis was subsequently induced by administrated 2.5% DSS in drinking water for the final seven days. Sulfasalazine-treated mice were the positive group. All doses of PRRE and sulfasalazine significantly ameliorated DSS-induced severity of colitis, as indicated by decreasing daily activity index and restoring colon shortening. Treatments with PRRE, but not sulfasalazine, significantly reduced the histopathological index and infiltration of inflammatory cells. Furthermore, the PRRE treatments effectively improved mucous in colonic goblet cells using PAS staining, and suppressed the production of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 induced by DSS, while sulfasalazine reduced only IL-1β and IL-6. This study suggested that PRRE had a greater anti-colitis effect than sulfasalazine. Thus, PRRE has a potential anti-colitis effect, and should be developed in a clinical trial as a natural active pharmaceutical ingredient for IBD.
炎症性肠病（IBD）已成为全球关注的问题。富含原花青素的红米提取物（PRRE）已被证明在细胞培养中可抑制炎症反应。然而，PRRE对结肠炎的抗结肠炎作用从未在动物中进行过研究。本研究旨在探讨PRRE对葡聚糖硫酸钠（DSS）诱导的小鼠结肠炎的保护作用。雄性小鼠口服给予50、250和500mg/kg/天的PRRE，持续21天。随后在最后七天通过在饮用水中给予2.5% DSS诱导急性结肠炎。柳氮磺胺吡啶治疗的小鼠为阳性组。所有剂量的PRRE和柳氮磺胺吡啶均显著改善了DSS诱导的结肠炎严重程度，表现为每日活动指数降低和结肠缩短恢复。PRRE治疗可显著降低组织病理学指数和炎症细胞浸润，而柳氮磺胺吡啶则无此作用。此外，PRRE治疗通过PAS染色有效改善结肠杯状细胞中的黏液，并抑制DSS诱导的促炎细胞因子TNF-α、IL-1β和IL-6的产生，而柳氮磺胺吡啶仅降低IL-1β和IL-6。本研究表明，PRRE的抗结肠炎作用比柳氮磺胺吡啶更强。因此，PRRE具有潜在的抗结肠炎作用，应作为IBD的天然活性药物成分进行临床试验开发。
