[Pathogenesis of precancerous lesions of gastric cancer and treatment mechanism of Weifuchun Capsules via NF-κB/NLRP3 inflammasome signaling pathway].

This study aims to investigate the pathogenesis of precancerous lesions of gastric cancer(PLGC) and explore the potential molecular mechanism of Weifuchun Capsules(WFC) in treating PLGC via the nuclear factor-κB(NF-κB)/NOD-like receptor protein 3(NLRP3) inflammasome signaling pathway. Ninety male SPF-grade Wistar rats were randomized into a normal feeding group and a modeling group. The normal feeding group received a regular diet, while the modeling group was subjected to the disease-syndrome combined modeling of PLGC. Specifically, the rats had free access to the water containing 120 μg·mL~(-1) N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and received a diet containing 0.05% ranitidine in an irregular feeding pattern(alternations between fasting and overfeeding). After 15 weeks, the rats in the normal feeding group were randomized into control, control-NF-κB activator betulinic acid(C-BA), and control-NF-κB inhibitor pyrrolidine dithiocarbamaten(C-PDTC) groups. Meanwhile, the rats in the modeling group continuously underwent the modeling procedure and were randomized into model, WFC, model-NF-κB activator(M-BA), and model-NF-κB inhibitor(M-PDTC) groups. The model group and control group were given aseptic water by intragastric administration, once a day. WFC was given at a dose(432 mg·kg~(-1)) 6 times the equivalent dose for adults(body weight: 60 kg) by gavage, once a day. The rats in the C-BA and M-BA groups were administrated with BA by intraperitoneal injection at a dose of 10 mg·kg~(-1), twice a week. The rats in the C-PDTC and M-PDTC groups were administrated with PDTC by intraperitoneal injection at a dose of 50 mg·kg~(-1), twice a week. The interventions were carried out for 4 weeks. Histopathological changes of the gastric mucosa were observed and scored by hematoxylin-eosin(HE) and alcian blue-periodic acid Sthiff(AB-PAS) staining. The levels of inflammatory cytokines including interleukin(IL)-1β, IL-6, IL-18, tumor necrosis factor-alpha(TNF-α), and IL-10 in the gastric tissue were determined by enzyme-linked immunosorbent assay(ELISA). The expression levels of proteins associated with the NF-κB/NLRP3 inflammasome in the gastric mucosa were determined by Western blot. The positive expression areas of proteins related to NF-κB/NLRP3 inflammasome in the gastric mucosa were measured by immunohistochemistry. The results showed that compared with the control group, the model, C-BA, and M-BA groups showed significantly risen scores of mucosal inflammation, degree of inflammatory activity, gland atrophy, and intestinal metaplasia, and the model and M-BA groups showed significanly risen scores of dysplasia. Compared with the model group, the WFC group demonstrated significantly declined scores of mucosal inflammation and degree of inflammatory activity, as well as declined scores of intestinal metaplasia and dysplasia. Compared with the control group, the model and C-BA groups showed significantly elevated levels of IL-1β, IL-6, IL-18, and TNF-α in the gastric tissue, and the model group showed significantly elevated level of IL-10. In addition, the model and C-BA groups showed significantly up-regulated expression of NF-κB p65, NLRP3, cysteine-aspartic acid protease 1(caspase-1), and apoptosis-associated speck-like protein containing a CARD(ASC) in the gastric mucosa and increased positive expression areas of NF-κB p65, NLRP3, and ASC. Compared with the model group, the WFC group showed significantly decreased levels of IL-1β, IL-6, IL-18, TNF-α, and IL-10 in the gastric tissue, and the M-PDTC group showed significantly lowered levels of IL-1β, IL-18, and TNF-α in the gastric mucosa. Both WFC and M-PDTC groups demonstrated significantly down-regulated expression levels of NF-κB p65, phosphorylated NF-κB p65(p-NF-κB p65), NLRP3, and caspase-1 in the gastric mucosa, along with significant decreases in the positive expression areas of NF-κB p65, NLRP3, and ASC. In conclusion, the pathogenesis of PLGC is closely related to the activation of the NF-κB/NLRP3 inflammasome signaling pathway. WFC can alleviate mucosal inflammation, inhibit glandular atrophy, partially reverse intestinal metaplasia, and reduce dysplasia to delay the process of inflammation-cancer transformation, and meanwhile it can effectively lower the levels of inflammatory cytokines and down-regulate the expression of pathway-related proteins in the stomach. Therefore, WFC may treat PLGC by inhibiting the NF-κB/NLRP3 inflammasome signaling pathway.