Moringin alleviates DSS-induced ulcerative colitis in mice by regulating Nrf2/NF-κB pathway and PI3K/AKT/mTOR pathway.

Ulcerative colitis (UC) is a main form of inflammatory bowel disease (IBD), which is a chronic and immune-mediated inflammatory disease. Moringin (MOR) is an isothiocyanate isolated from Moringa oleifera Lam., and has been recognized as a promising potent drug for inflammatory diseases and antibacterial infections. The present study investigated the role of moringin in dextran sulfate sodium (DSS)-induced UC mice. Mouse colitis was induced by adding DSS to the drinking water for seven consecutive days. Our experimental results showed that MOR relieves DSS-induced UC in mice by increasing body weight and colonic length, and reducing the disease activity index and histological injury. Mechanistically, MOR improves intestinal barrier function by increasing the expression of tight junction proteins (TJPs) and enhancing the secretion of mucin in DSS-induced mice. MOR inhibits inflammatory response and intestinal damage by regulating Nrf2/NF-κB signaling pathway and modulating the PI3K/AKT/mTOR pathway. Furthermore, in Nrf2 knockout (Nrf2-/-) mice, the protective effects of MOR on DSS-induced UC were abolished. Meanwhile, treatment with MOR reduced inflammation and cell damage via regulating Nrf2/NF-κB pathway in a lipopolysaccharide (LPS)-induced inflammation model of Caco-2 cells. In contrast, ML385, an Nrf2 inhibitor, might eliminate the protection provided by MOR. Notably, treatment with MOR significantly up-regulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), suggesting that MOR may be a potential PPAR-γ activator. In conclusion, MOR exerts protective effect in UC by improving intestinal barrier function, regulating Nrf2/NF-κB and PI3K/AKT/mTOR signaling pathways, and another effect associated with the regulation of PPAR-γ expression.

Pharmacological effects of ginseng and ginsenosides on intestinal inflammation and the immune system.

Intestinal inflammatory imbalance and immune dysfunction may lead to a spectrum of intestinal diseases, such as inflammatory bowel disease (IBD) and gastrointestinal tumors. As the king of herbs, ginseng has exerted a wide range of pharmacological effects in various diseases. Especially, it has been shown that ginseng and ginsenosides have strong immunomodulatory and anti-inflammatory abilities in intestinal system. In this review, we summarized how ginseng and various extracts influence intestinal inflammation and immune function, including regulating the immune balance, modulating the expression of inflammatory mediators and cytokines, promoting intestinal mucosal wound healing, preventing colitis-associated colorectal cancer, recovering gut microbiota and metabolism imbalance, alleviating antibiotic-induced diarrhea, and relieving the symptoms of irritable bowel syndrome. In addition, the specific experimental methods and key control mechanisms are also briefly described.