Carvacrol Ameliorates DSS-Induced Intestinal Inflammation in Rats by Suppressing the TLR4/NF-κB Pathway

The present study aimed to explore the therapeutic effects of carvacrol on the ulcerative colitis (UC) inflammation model induced by DSS (dextran sulfate sodium) in rats. Forty rats were randomly divided into the blank, model, low-, middle-, and high-dose carvacrol groups. The rats drank 4.5% DSS for 5 consecutive days to induce the UC model, except for the blank group. Different concentrations of either carvacrol or purified water were supplied by intragastric administration for 7 consecutive days to assess the protective effect of carvacrol on inflammation in UC rats involving the TLR4/NF-kappa B signaling pathway. In vivo administration of carvacrol was found to ameliorate the symptoms of colitis in rats. Carvacrol significantly improved the pathological symptoms of colitis in the model group and reduced the DAI and pathological scores of rats. At the same time, carvacrol can reduce the expression of IL-6 and TNF-alpha induced by DSS, inhibit the activation of TLR4, hinder the nuclear translocation of NF-kappa B (P65), reduce the cleavage of the apoptosis-related protein cleaved-caspase 3, and protect colon cell apoptosis. The results of in vitro experiments showed that carvacrol has a significant inhibitory effect on cell apoptosis caused by the activation of TLR4 induced by LPS and pcDNA3.1tlr4. Research results revealed that carvacrol has a certain protective effect against inflammation-induced injury in ulcerative colitis rats via inhibiting the activation of the TLR4/NF-kappa B signaling pathway.