新型大麻制剂O-1602和大麻二酚对DSS诱导的小鼠结肠炎的抗炎作用及其机制

目的:研究新型大麻类制剂O-1602和大麻二酚(CBD)对硫酸葡聚糖钠(DSS)诱导的小鼠实验性结肠炎的抗炎作用,并通过测定p38丝裂原活化蛋白激酶(MAPK)的活化程度,探讨其可能的作用机制。方法:对C57BL/6小鼠给予含4%DSS的饮用水连续饮用7d,建立实验性结肠炎模型。造模期间分别给小鼠腹腔注射O-1602(5mg/kg)、CBD(1mg/kg)或p38MAPK抑制剂SB203580(5μmol/kg)。造模结束后用结肠炎评分系统对各组结肠炎局部情况进行评估;同时检测血浆中肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和细胞因子诱导的中性粒细胞趋化因子1(CINC-1)的水平(ELISA法),以及肺组织髓过氧化物酶(MPO)活性,以评价各处理组结肠炎的炎症反应情况;采用Westernblotting法检测结肠组织p38及p-p38蛋白表达水平;免疫组化方法检测结肠G蛋白偶联受体55(GPR55)的表达。结果:O-1602和CBD能够改善小鼠实验性结肠炎的病理损害,降低血浆TNF-α、IL-6和CINC-1的水平以及肺组织MPO的活性(P<0.05);O-1602、CBD以及SB203580处理组结肠组织,p38磷酸化程度较结肠炎组显著降低(P<0.05);免疫组化提示小鼠结肠GPR55受体表达较少,主要分布在黏膜下层,结肠炎时GPR55表达变化不明显。结论:GPR55在小鼠结肠有较少表达,揭示O-1602和CBD能够减轻DSS诱导的小鼠结肠炎炎症反应,其作用机制可能与抑制p38MAPK信号通路有关。

Roles of novel cannabinoid chemicals O-1602 and cannabidiol in DSS-induced mouse colitis

AIM:To investigate the roles of O-1602 and cannabidiol(CBD) in dextran sulfate sodium(DSS)-induced mouse colitis.METHODS: The model of colitis was induced in C57BL/6 mice by drinking water containing 4% DSS for 7 days.The model mice were treated with O-1602(5 mg/kg),CBD(1 mg/kg) or SB203580 an inhibitor of p38 mitogen-activated protein kinase(MAPK) at dose of 5 μmol/kg].A colitis scoring system was used to evaluate the colon local lesion,and the systemic inflammatory responses were observed by detecting the plasma levels of tumor necrosis factor α(TNF-α),interleukin 6(IL-6) and cytokine-induced neutrophil chemoattractant 1(CINC-1),and the activity of myeloperoxidase(MPO) in the lung tissues.The expression of G protein-coupled receptor 55(GPR55) was detected by the method of immunohistochemistry.The expression of p38 and phosphorylated p38(p-p38) in colon tissues was determined by Western blotting.RESULTS: O-1602 and CBD improved the pathological changes in the mice with DSS-induced colitis and decreased the plasma levels of TNF-α,IL-6 and CINC-1,and the activity of MPO in the lung tissues(P<0.05).Lower expression of p-p38 was observed after treatment with O-1602,CBD and SB203580(P<0.05).The expression of GPR55 was mainly in the submucosa of mouse colon tissues.CONCLUSION: O-1602 and CBD show protective effect on the mice with experimental colitis,and the anti-inflammatory roles of O-1602 and CBD are related to the inhibition of p38 MAPK.The expression level of GPR55 in the submucosa of mouse colon tissue is low.