No abstract

Palamneus gravimanus envenomated rats showed dose-dependent alterations in serum biochemical parameters. Sub lethal doses of 100, 200, and 400 microg/kg of P. gravimanus venom were injected intramuscularly into rats. Blood samples were collected by heart puncture before and 4 h after crude venom administration. Serum was analyzed for glucose, blood urea nitrogen (BUN), uric acid, total protein, cholesterol, sodium, potassium, inorganic phosphorus, alkaline phosphatase, aspartate aminotransferase (AST-SGOT), alanine amino-transferase (ALT-SGPT), lactate dehydrogenase (LDH), and creatinine phosphokinase (CPK). Statistically significant increases in serum levels of glucose, creatinine, AST, ALT, BUN, CPK, and LDH and significant decreases in serum levels of total protein, uric acid, cholesterol, calcium, and potassium 4 h after venom administration could be due to the toxic action of P. gravimanus venom on certain organs in rats.

Snake venoms are rich in enzymes such as phospholipase A 2 , proteolytic enzymes, hyaluronidases and phosphodiesterases, which are well characterized. However, L-amino acid oxidase (LAO EC.1.4.3.2) from snake venoms has not been extensively studied. A novel L-amino acid oxidase from Bungarus caeruleus venom was purified to homogeneity using a combination of ion-exchange by DEAE-cellulose chromatography and gel filtration on Sephadex® G-100 column. The purified monomer of LAO showed a molecular mass of 55 ±1 kDa estimated by SDS-PAGE. The specific activity of purified LAO was 6,230 ± 178 U/min/mg, versus 230 ± 3.0 U/min/mg for the whole desiccated venom, suggesting a 27-fold purification with a 25% yield. Optimal pH and temperature for maximum purified enzyme activity were 6.5 and 37°C, respectively. Platelet aggregation studies show that purified LAO inhibited ADP-induced platelet aggregation dose-dependently at 0.01 to 0.1 μM with 50% inhibitory concentration (IC 50 ) of 0.04 μM, whereas at a 0.08 μM concentration it did not induce appreciable aggregation on normal platelet-rich plasma (PRP). The purified protein catalyzed oxidative deamination of L-amino acids while the most specific substrate was L-leucine. The purified LAO oxidizes only L-forms, but not Dforms of amino acids, to produce H 2 O 2 . The enzyme is important for the purification and determination of certain amino acids and for the preparation of α-keto acids.

Bungarus coeruleus, a common venomous snake allied to the cobra, is responsible for most envenomations in India. This study examines the pathological effects of B. caeruleus venom and the associated biochemical changes in a rat model. Increased serum aspartate aminotransferase (48%), creatine kinase (30%), and lactate dehydrogenase (6%) were detected after a sublethal dose of 25 microg/kg of B. caeruleus venom was injected intramuscularly into rats observed for 180 min. The venom induced hyperglycemia and increased serum alkaline phosphatase (55%) and urea (90%) concentrations, whereas cholesterol and triglycerides remained normal. Histopathological changes in the heart-hemorrhage, multifocal areas of myocardial fiber necrosis-and constriction of blood vessels in the kidney, with congested vessels, hemorrhage and necrosis of proximal tubules, liver congestion, and hemorrhage were found.

The neurotoxin purified from the venom of Bungarus caeruleus causes a neuromuscular blockade on acetylcholine-induced muscle twitch response in isolated frog rectus abdominis muscle preparation. Neuromuscular blockade produced by d-tubocurarine on acetylcholine-induced muscle twitch response in an isolated frog rectus abdominis muscle preparation was reversed to normal muscle twitch response in presence of neostigmine. Whereas the purified neurotoxin produced an irreversible neuromuscular blockade in presence of the same strength of neostigmine. As it is already known, botulinum toxin, which also brings about neuromuscular blockade, is effectively used as a drug in the treatment of painful movement disorders. Since the purified toxin also causes paralysis of the muscle, we propose its possible efficacy in the treatment of neuromuscular disorders