shikonin and Colitis

Shikonin is a natural product with antioxidant and anti-inflammatory activities. The biological activity of shikonin is still not fully understood, as well as its association with innate immunity and immune and inflammatory bowel disease (IBD) in humans. In this study, the toxicity of shikonin on Raw264.7 cells was assayed by MTT, and polarization of inflammatory macrophages was determined by flow cytometry. The results showed that shikonin can inhibit the polarization of macrophages towards M1 type and significantly inhibited the production of NO in the concentration range of 0.5-1 μM. In addition, after treatment with shikonin, the production of IL-1β and TNF-α was significantly decreased. After shikonin administration, the body weight loss and decrease of colon length were significantly suppressed in DSS-treated colitis C57BL/6 mice. The pro-inflammatory cytokines TNF-α and IL-1β in colonic homogenate were significantly decreased. Shikonin treatment resulted in a notable improvement in the histopathological manifestations in DSS-treated animals at 25/50 mg/kg. Meanwhile, we found that shikonin can regulate differentiation of T helper 17 cell (Th17)/regulatory T cell (Treg), thereby regulating the balance of Th17/Treg cells and exerting an anti-inflammatory effect in IBD animal models. In conclusion, we found that shikonin protects against DSS-induced acute colitis by, among other things, reducing immune cell infiltration, polarizing macrophages, and regulating Th17/Treg differentiation, as well as by downregulating the release of inflammatory cytokines. These findings showed that shikonin can improve inflammation by affecting macrophage polarization. Our experimental data provide experimental evidence and theory basis for research on anti-inflammatory effects for the shikonin as health or functional food.

Topics: Animals; Colitis; Colon; Cytokines; Disease Models, Animal; Humans; Inflammatory Bowel Diseases; Mice; Mice, Inbred C57BL; Tumor Necrosis Factor-alpha

Colorectal cancer (CRC) and inflammatory bowel disease (IBD) are the most common diseases of human digestive system. Nowadays, the influence of the inflammatory microenvironment on tumorigenesis has become a new direction, and the exploration of relative molecular mechanism will facilitate the discovery and identification of novel potential anti-cancer molecules.. Natural shikonin (SK) and acetyl-shikonin (acetyl-SK) was administered to azoxymethane (AOM)/dextran sodium sulphate (DSS)-induced colitis-associated colorectal cancer (CAC) mice model by gavage to investigate their therapeutic effects. Moreover, fresh feces and colon tissues were collected for determining the function of SK and acetyl-SK on the gut microbes and protein expression, respectively.. Both SK and acetyl-SK decreased AOM/DSS-induced CAC, and regulated the intestinal flora structure in CAC mouse model. They, especially SK, improved species richness, evenness and diversity of intestinal flora, recovered the upregulated ratio of Firmicutes to Bacteroidota (F/B ratio) which symbolizes gut microbiota dysbiosis. SK and its derivative increased the beneficial bacteria g__norank_f__Muribaculaceae, Lactobacillus, Lachnospiraceae_NK4A136_Group, and reduced those harmful ones including Ileibacterium and Coriobacteriaceae UCG-002. Notably, AOM/DSS caused significant increase in the abundance of Ileibaterium valens and g__norank_f__norank_o__Clostridia_UCG-014, which were not previously reported in studies of colonic inflammation or cancer, and the disorder was reversed by 20 mg/kg of SK. In our current study, the action of SK and acetyl-SK is dose-dependent, and 20 mg/kg SK exhibited the most effective functions, even better than the positive drug mesalazine. Moreover, differential proteomics and ELISA results showed that SK could recover the increase of pro-inflammatory cytokines (including IL-1β, IL-6 and TNF-α), the upregulation of pyruvate kinase isozyme type M2 (PKM2) and some other proteins (mainly concentrated in transcriptional mis-regulation in cancer and IL-17 signaling pathways), and the downregulation of Aldh1b1-Acc3-Maoa and Μgt2b34-Aldh1a1-Aldh1a7 involved in Wnt/β-catenin signaling pathway.. Our study identified SK and acetyl-SK, especially SK, as potential preventive agents for CAC through regulating both gut microbes and pathways involved in inflammation and cancer such as Wnt/β-catenin signaling pathway.

Topics: Animals; Azoxymethane; Bacteroidetes; Colitis; Colitis-Associated Neoplasms; Colorectal Neoplasms; Dextran Sulfate; Disease Models, Animal; Firmicutes; Humans; Inflammation; Mice; Mice, Inbred C57BL; Naphthoquinones; Tumor Microenvironment

Topics: Animals; Chitosan; Colitis; Colon; Cytokines; Hydrogen-Ion Concentration; Inflammatory Bowel Diseases; Mice; Nanoparticles