The toxic and biological activities of four samples of Trimeresurus purpureomaculatus venom were examined. The lethality, protein composition and biological activities of the four venom samples were similar. Three of the venom samples had LD50 (i.v.) values of 0.9 micrograms/g while the fourth had a lower LD50 (i.v.) of 0.45 micrograms/g. All four venom samples exhibited hemorrhagic, edema-inducing, anticoagulant and thrombin-like activities as well as the usual enzymes found in crotalid venoms. DEAE-Sephacel ion exchange chromatographic fractionation of the venom yielded 10 protein fractions. Only two fractions (fractions A and F) were lethal to mice; the major lethal fraction being fraction F. This fraction had an LD50 (i.v.) of 0.2 micrograms/g and exhibited hemorrhagic, edema-inducing and thrombin-like activity. It also exhibited phospholipase A, arginine ester hydrolase, arginine amidase, protease, 5'-nucleotidase, acetylcholinesterase and alkaline phosphomonoesterase activities. The lethal potency of fraction F is potentiated by fraction G, which exhibited anticoagulant activity as well as hemorrhagic, edema-inducing and enzymatic activities. Fractions F plus G account for almost 100% of the lethal potency of the venom.
1. The major phospholipase A2 (PLA-DE4) of the venom of Trimeresurus purpureomaculatus (shore pit viper) has been purified to electrophoretic homogeneity. 2. The isoelectric point of the purified enzyme was determined to be 4.20, and the mol. wt was 31,700 as estimated by Sephadex G-75 gel filtration chromatography; and 14,000 as estimated by SDS-polyacrylamide gel electrophoresis. The purified enzyme hydrolyzed phosphatidylcholine (PC) faster than phosphatidylethanolamine (PE), whereas phosphatidylserine (PS) was not hydrolyzed at all (PC greater than PE greater than PS =0). However, in reaction system consisted of mixtures of PC and PS, phosphatidylserine was effectively hydrolyzed by the enzyme. 4. The phospholipase A2 exhibited edema-forming activity but not hemolytic, hemorrhagic or anticoagulant activities. It was not lethal to mice at a dosage of 10 micrograms/g by i.v. route.
Ophiocordyceps sinensis is one of the most sought-after medicinal fungi used to treat various medical conditions such as respiratory diseases, liver and kidney dysfunctions. In China, it is widely used for alleviation of frequent urination where patients treated with O. sinensis have shown improvement in nocturia, which is the most common symptom of overactive bladder (OAB). Many studies have reported its anticancer, anti-inflammatory, anti-oxidative, hypoglycaemic and vasorelaxation properties. These properties are attributable to the presence of bioactive components such as polysaccharides, proteins and nucleosides. This mini-review highlights the medicinal potential of O. sinensis in alleviating OAB, which is a debilitating condition with a profound impact on the quality of life in a high proportion of older people. Four possible mechanisms of action of O. sinensis are suggested. Firstly, the relaxation of bladder smooth muscle through calcium dynamic, production of nitric acid (NO) and adenosine triphosphate (ATP). A second mechanism proposed is through the suppression of micturition reflex. The unequivocal properties of O. sinensis as anti-inflammatory and anti-oxidant, are two other plausible explanations, as both chronic inflammation and accumulation of oxidative stress molecules are associated with OAB exacerbation. With the recent success in cultivation of O. sinensis and the positive results from toxicity studies, a better understanding of its pharmacological actions can be further substantiated, including its use for relieving OAB.