[Protective effect of total triterpenoids from Chaenomeles speciosa against Helicobacter pylori-induced gastritis in mice].

This study investigated the protective effect of total triterpenoids from Chaenomeles speciosa against Helicobacter pylori(Hp)-induced gastritis in mice and explored its possible mechanism. The chronic atrophic gastritis(CAG) model mice were randomly divided into four groups of model, total triterpenoids from C. speciosa(50 and 100 mg·kg~(-1)) and triple therapy, with C57 BL/6 J mice without Hp infection taken as the normal group. Mice in the treatment groups were given corresponding drugs once a day for 4 weeks. Then the following indexes were detected: the contents of reactive oxygen species(ROS), monocyte chemotactic protein 1(MCP-1), keratinocyte chemokines(KC), TNF-α, IL-1β, IL-6, IL-18, IL-4 and IL-10 in blood and gastric tissue, the activities and contents of LDH, MPO, SOD, GSH-Px, CAT and MDA in gastric tissue and the activities of β-glucuronidase, β-galactosidase, cathepsins B and D in blood, gastric tissue and lysosome. Besides, the mRNA expression levels of Toll-like receptor 4(TLR4), myeloid differentiation factor 88(MyD88), Bcl-2, Bcl-xl, Bax and Bad in gastric tissue were determined by quantitative real-time PCR. Western blot was employed to detect the protein expression levels of TLR4, MyD88, p-IKKβ, p-IκBα, NOD-like receptor 3(NLRP3), apoptosis-associated speck-like protein(ASC), pro-caspase-1, caspase-1, thioredoxin-interacting protein(TXNIP), pro-IL-1β, pro-IL-18, Bcl-2, Bcl-xl, Bax, Bad, cytochrome C, apoptotic protease-activating factor-1(Apaf-1), pro-caspase-9, pro-caspase-3, cleaved-caspase-9, cleaved-caspase-3, poly(ADP-ribose) polymerase 1(PARP-1), cleaved-PARP-1 and cytosol and nucleus NF-κB p65 in gastric tissue. The results indicated that the total triterpenoids from C. speciosa significantly suppressed Hp proliferation, alleviated the damage to gastric mucosa and improved lymphocyte infiltration and gland atrophy. They were also effective in reducing the activities of β-glucuronidase, β-galactosidase, cathepsins B and D in blood and gastric tissue, elevating the activities of β-glucuronidase and cathepsin D in lysosomal organelles, decreasing the contents of ROS, MCP-1, KC, TNF-α, IL-1β, IL-6, IL-18 in blood, MDA content and MPO and LDH activities in gastric tissue and increasing the contents of IL-4 and IL-10 in blood and activities of SOD, CAT and GSH-Px in gastric tissue. Other phenomena were also observed after the treatment with total triterpenoids from C. speciosa, including the down-regulation of the mRNA and protein expression levels of TLR4, MyD88, Bax and Bad, the protein expression levels of p-IKKβ, p-IκBα, NLRP3, ASC, pro-caspase-1, caspase-1, TXNIP, pro-IL-1β, pro-IL-18, cytochrome C, Apaf-1, cleaved-caspase-9, cleaved-caspase-3, cleaved-PARP-1 and nuclear NF-κB p65, reduction of p-IKKβ/IKKβ and p-IκBα/IκBα ratios and up-regulation of the mRNA and protein expression levels of Bcl-2 and Bcl-xl, up-regulation of pro-caspase-9, pro-caspace-3, cytosol NF-κB p65 protein expression levels and Bcl-2/Bax and Bcl-xl/Bad ratios in gastric tissue. These aforementioned results suggest that the total triterpenoids from C. speciosa have significant protective effects against CAG induced by Hp, and its mechanism may be related to enhancing the function of endogenous antioxidant system, suppressing the oxidative stress and inflammatory reaction induced by Hp, correcting lysosomal dysfunction and inflammatory activation of TLR4/NF-κB/NLRP3 inflammasome signaling pathway and thus inhibiting mitochondria-mediated apoptosis.