Rajesh R, Raghavendra Gowda C D, Nataraju A, Dhananjaya B L, Kemparaju K, Vishwanath B S
Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570 006, Karnataka, India.
Toxicon. 2005 Jul;46(1):84-92. doi: 10.1016/j.toxicon.2005.03.012.
The latex of Calotropis gigantea is a rich source of useful components that has medicinal properties and one of the main applications is in controlling bleeding. The crude latex extract contained many proteins, which are highly basic in nature and exhibited strong proteolytic activity. The crude extract hydrolyses casein, human fibrinogen and crude fibrin clot in a dose-dependent manner. The hydrolyzing activity was completely inhibited by IAA indicating they belong to the super family, cysteine proteases. Crude extract hydrolyses Aalpha, Bbeta and gamma subunits of fibrinogen. Among all the subunits the preferential subunit to get hydrolyzed was Aalpha followed by Bbeta and gamma subunit is highly resistant and hydrolyzed at higher protein concentration or over a prolonged incubation time. The crude extract hydrolysis crude fibrin clot strongly compared to trypsin and papain. Pharmacologically the crude extract is hemorrhagic and induces skin hemorrhage at >75 microg and reduces the coagulation time of citrated plasma from 150 to 47 s and promotes blood coagulation. Procoagulation and blood clot hydrolysis are important in wound healing process. This is due to unique cysteine proteases of plant latex and is responsible for the pharmacological actions observed in folk medicine.
牛角瓜的乳胶富含具有药用特性的有用成分,其主要应用之一是控制出血。粗乳胶提取物含有许多蛋白质,这些蛋白质本质上是高度碱性的,并表现出很强的蛋白水解活性。粗提取物以剂量依赖的方式水解酪蛋白、人纤维蛋白原和粗纤维蛋白凝块。水解活性被吲哚乙酸完全抑制,表明它们属于半胱氨酸蛋白酶超家族。粗提取物水解纤维蛋白原的α、β和γ亚基。在所有亚基中,优先被水解的亚基是α,其次是β,γ亚基高度抗水解,在较高蛋白质浓度或延长孵育时间时才会被水解。与胰蛋白酶和木瓜蛋白酶相比,粗提取物对粗纤维蛋白凝块的水解作用更强。从药理学角度来看,粗提取物具有出血性,在剂量大于75微克时会引起皮肤出血,将枸橼酸盐血浆的凝血时间从150秒缩短至47秒,并促进血液凝固。促凝血和血凝块水解在伤口愈合过程中很重要。这归因于植物乳胶中独特的半胱氨酸蛋白酶,并且是民间医学中观察到的药理作用的原因。