Oral supplementation of tocotrienol-rich fraction alleviates severity of ulcerative colitis in mice

Abstract

Ulcerative colitis (UC) is characterized by damaged colonic mucosa and submucosa layers that are caused by excessive inflammatory reactions and oxidative stress. This study aimed to examine the use of tocotrienol-rich fraction (TRF) in mitigating damages caused by UC on the colon epithelium. Dextran sulfate sodium (DSS)-induced UC mice were treated with vehicle control, TRF, alpha-tocopherol (aTP) and 5-aminosalicylic acid (5-ASA). Observable clinical signs, quality of stool, histopathological scoring, inflammatory and oxidative markers were assessed. Vitamin E levels of colons and plasma were quantified. Oral supplementation of TRF significantly reduced the severity of DSS-induced UC by lowering the disease activity index (DAI) and histopathological inflammatory scoring. TRF also attenuated the DSS-induced enlargement of spleen and shortening of the colon. TRF has demonstrated marked anti-inflammatory and antioxidative properties indicated by the attenuation of DSS-induced upregulation of inflammation and oxidative stress markers including interleukin (IL)-6, IL-17, tumor necrosis factor (TNF)-a, myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), nitric oxide (NO), malondialdehyde (MDA) and pNF-kB. These improvements were similar to that of 5-aminosalicylic acid (5-ASA) treatment. In contrast, aTP did not demonstrate evident clinical and histopathological improvements. The superior protective effect of TRF may be ascribed to the preferential absorption of TRF by the gut mucosa. TRF alleviated the signs and symptoms of acute UC in murine model via the reduction of local inflammatory reactions and oxidative stress. These effects suggested that TRF could serve as a gut health supplement for preventive measures for UC condition in patients.