Unconjugated
This study evaluated the protective effects of inhibiting caspase-1 activity or gastric acid secretion on acute gastric injury in mice. AC-YVAD-CMK, omeprazole, or vehicle were administered to mice before cold-restraint stress- or ethanol-induced gastric injury. Survival rates and histological evidence of gastric injury of mice pretreated with AC-YVAD-CMK or omeprazole, and exposed to cold-restraint stress, improved significantly relative to the vehicle group. The increased levels of tumour necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-18 following cold-stress injury were decreased by AC-YVAD-CMK, but not omeprazole, pretreatment. The increased expression of CD68 in gastric tissues was inhibited significantly by AC-YVAD-CMK pretreatment. Inhibiting caspase-1 activity in the NLRP3 inflammasome decreased gastric cell apoptosis, and the expression of Bax and cleaved caspase-3. AC-YVAD-CMK pretreatment significantly inhibited cold-restraint stress-induced increases in the expression of phosphorylated IκB-alpha and P38. General anatomy and histological results showed the protective effect of AC-YVAD-CMK on ethanol-induced acute gastric injury. Overall, our results showed that the caspase-1 inhibitor AC-YVAD-CMK protected against acute gastric injury in mice by affecting the NLRP3 inflammasome and attenuating inflammatory processes and apoptosis. This was similar to the mechanism associated with NF-κB and P38 mitogen-activated protein kinase signalling pathways.
Hepatic fibrosis is concomitant with liver inflammation, which has been highlighted as significant treatment of chronic liver disease. We previously demonstrated that tetramethylpyrazine (TMP), the effective component of Ligusticum chuanxiong Hort, can inhibit the activation of HSCs and consequential anti-hepatic fibrosis. In this study, our work demonstrated that TMP improved liver histological architecture, decreased hepatic enzyme levels and attenuated collagen deposition in the rat fibrotic liver. In addition, TMP significantly protected the liver from CCl4-caused injury and fibrogenesis by suppressing inflammation with reducing levels of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), NLRP3, nuclear factor-kappa B (NF-κB) and interleukin-1β (IL-1β). Experiments in vitro showed that TMP inhibited inflammatory cytokine expression in HSCs associated with disrupting platelet-derived growth factor-b receptor (PDGF-βR)/NLRP3/caspase1 pathway. These data collectively indicate that TMP can attenuate liver inflammation in liver fibrosis and possibly by targeting HSCs via PDGF-βR/NLRP3/caspase1 pathway. It provides novel mechanistic insights into TMP as a potential therapeutic remedy for hepatic fibrosis.