Girish K S, Kemparaju K
Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore-570 006, India.
Life Sci. 2006 Feb 23;78(13):1433-40. doi: 10.1016/j.lfs.2005.07.015. Epub 2005 Oct 25.
Hyaluronidase is present virtually in all snake venoms and has been known as a "spreading factor." The enzyme damages the extracellular matrix at the site of the bite, leading to severe morbidity. In this study, the benefits of inhibiting the hyaluronidase activity of Indian cobra (Naja naja) venom have been investigated. Anti-NNH1 and aristolochic acid both inhibited the in vitro activity of the purified hyaluronidase, (NNH1) and the hyaluronidase activity of whole venom in a dose-dependent manner. Both anti-NNH1 and aristolochic acid abolished the degradation of hyaluronan in human skin tissue sections by NNH1 and by whole venom. Aristolochic acid quenched the fluorescent emission of NNH1. A non-competitive mechanism of NNH1 inhibition was observed with aristolochic acid. NNH1 potentiates the toxicity of Daboia russellii VRV-PL-VIII myotoxin and hemorrhagic complex-I. However, the potentiation of toxicity was inhibited dose-dependently by anti-NNH1 and aristolochic acid. Further, mice injected with whole venom which had been preincubated with anti-NNH1/aristolochic acid, showed more than a two-fold increase in survival time, compared to mice injected with venom alone. A more moderate increase in survival time was observed when mice were injected with anti-NNH1/aristolochic acid 10 min after whole venom injection. This study illustrates the significance of venom hyaluronidase in the pathophysiology of snake venom poisoning and the therapeutic value of its inhibition.
透明质酸酶几乎存在于所有蛇毒中，一直被称为“扩散因子”。该酶会破坏咬伤部位的细胞外基质，导致严重的发病情况。在本研究中，对抑制印度眼镜蛇（眼镜蛇属）毒液中透明质酸酶活性的益处进行了研究。抗NNH1和马兜铃酸均以剂量依赖的方式抑制纯化的透明质酸酶（NNH1）的体外活性以及全毒液的透明质酸酶活性。抗NNH1和马兜铃酸均消除了NNH1和全毒液对人皮肤组织切片中透明质酸的降解作用。马兜铃酸淬灭了NNH1的荧光发射。观察到马兜铃酸对NNH1的抑制作用为非竞争性机制。NNH1会增强锯鳞蝰VRV-PL-VIII肌毒素和出血复合物-I的毒性。然而，抗NNH1和马兜铃酸可剂量依赖性地抑制毒性增强。此外，与单独注射毒液的小鼠相比，注射了预先与抗NNH1/马兜铃酸预孵育的全毒液的小鼠存活时间增加了两倍多。在全毒液注射10分钟后注射抗NNH1/马兜铃酸时，观察到存活时间有较为适度的增加。本研究阐明了毒液透明质酸酶在蛇毒中毒病理生理学中的重要性及其抑制的治疗价值。
