Effect of mesenchymal stem cells derived exosomes and green tea polyphenols on acetic acid induced ulcerative colitis in adult male albino rats

Ulcerative colitis (UC) is one of the inflammatory bowel diseases (IBD) that result in recurrent inflammation plus ulcers of the colon and rectum. Recently, mesenchymal stem cell-derived exosomes MSC-EXs have shown a lot of promise for the treatment of gut disorders, with cell regeneration and angiogenesis. Green tea polyphenols (GTPs) display specific beneficial effects on health and pathologies. The aim of this study was to explore the possible effect of MSC-EXs and GTPs on acetic acid-induced UC in rats. Sixty adult male rats were divided into five groups: group I, control group; group II, UC; group ΙIΙ, UC treated with GTPs; group ΙV, UC treated with MSC-EXs; and group V, UC treated with combined GTPs and MSC-EXs. Colonic samples were processed for histological and immunohistochemical methods. Expression of CXCR2 and TLR4 levels was measured. Groups ΙI and III showed ulceration, loss of surface columnar epithelium, disturbed crypt architecture with few goblet cells, and many cellular infiltrations with the overexpression of CXCR2 and TLR4. Group IV showed attenuation of some histological changes. Group V showed improvement of the most histological and immunohistochemical changes described previously. MSC-EXs represent future therapeutic hopes for chronic intestinal inflammatory states, keeping the integrity of innate immunity through their regenerative and anti-inflammatory effects. The combination of GTPs and MSC-EXs was more effective and produced an additive effect than using MSC-EXs alone.