夏枯草水提物对过敏性结膜炎大鼠NLRP3/Caspase1/IL-1β通路的影响

Effect of water extract of Prunella vulgaris on NLRP3/Caspase-1/IL-1β pathway in rats with allergic conjunctivitis

目的:探讨夏枯草水提物对鸡卵清蛋白(ovalbumin,OVA)诱导的过敏性结膜炎模型大鼠角结膜的抗炎作用及其机制。方法:将60只SPF级实验SD大鼠随机分为空白对照组、模型组、阳性药物组(氯雷他定)、夏枯草低(1.26 g·kg-1)、中(2.52 g·kg-1)、高剂量组(5.04 g·kg-1)6组,除空白对照组外,其他组均运用OVA建立过敏性结膜炎病理模型。造模成功后连续灌胃给药10 d,正常对照组、模型组灌胃(ig)给予生理盐水。末次给药后,大鼠腹主动脉取血,酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)法检测血清中白细胞介素1beta(interleukin 1beta,IL-1β)的水平,取大鼠角膜和肝行石蜡切片并做伊红(HE)染色观察组织病理改变,取大鼠角膜行冰冻切片并进行免疫组化检测Nod样受体蛋白3(NACHT,LRR and PYD domains-containing protein 3,NLRP3),含半胱氨酸的天冬氨酸蛋白水解酶(cysteinyl aspartate specific proteinase 1,Caspase-1)和IL-1β的表达,蛋白印迹法Western Blot法检测角膜组织NLRP3,Caspase-1和IL-1β的表达。结果:夏枯草能显著降低过敏性结膜炎大鼠血清中的IL-1β,且能很好地改善过敏性结膜炎大鼠角膜的炎症病变,显著降低角膜组织中NLRP3,Caspase-1和IL-1β炎症蛋白的表达,缓解肝脏水肿程度。结论:夏枯草可通过NLRP3/Caspase1/IL-1β通路有效缓解过敏性结膜炎大鼠角结膜的炎症。

Objective: To investigate the anti-inflammatory effect and mechanism of water extract of Prunella vulgaris on allergic conjunctivitis model rats induced by chicken ovalbumin( OVA). Methods: 60 SD rats were randomly divided into 6 groups,including blank control group,model group,positive drug group( loratadine),Prunella vulgaris low dose( 1. 26 g·kg-1),medium dose( 2. 52 g·kg-1),and high dose group( 5. 04 g·kg-1).Except for the blank control group,the other groups were given with OVA to establish allergic conjunctivitis model.Then,the rats in the positive control and Prunella vulgaris groups were given continuously by gavage for 10 days.Those in the control group and the model group were given normal saline. After the last administration,blood was taken through abdominal aorta. The serum levels of interleukin 1 beta( IL-1β) were detected by enzyme linked immunosorbent assay( ELISA) method. Paraffin sections of cornea and liver were taken and then HE staining was performed to observe histopathology. The corneal frozen sections were taken and immunohistochemically detected for the expressions of NACHT,LRR and PYD domains-containing protein 3( NLRP3),cysteinyl aspartate specific proteinase 1( Caspase-1) and IL-1β. The expressions of NLRP3,Caspase-1 and IL-1β in corneal tissue were detected by Western Blot. Results: Prunella vulgaris significantly reduced IL-1β in the serum of rats with allergic conjunctivitis,and improved inflammatory lesions in the cornea of rats with allergic conjunctivitis,significantly reduced expression of protein NLRP3,Caspase-1 and IL-1β inflammation in corneal tissue,and relieved the liver edema. Conclusion: Prunella vulgaris can effectively alleviate inflammation of cornea and conjunctiva in rats with allergic conjunctivitis via NLRP3/Caspase1/IL-1β pathway.