Effect of scorpion (Leiurus Quinquestriatus H and E) venom on lipid metabolism

Protective effects of melatonin against oxidative damage induced by Egyptian cobra (Naja haje) crude venom in rats

Naja haje envenomation is one of the leading causes of death due to snakebite. Antiserum therapy sometimes fails to provide enough protection against venom toxicity. In this study, we investigated the protective effects of melatonin against N. haje venom in rats. The animals were injected with venom (0.25mg/kg) and/or melatonin (10mg/kg) and compared with vehicle-treated rats. There was oxidative/nitrosative damage and apoptosis in the liver, heart, and kidneys of venom-injected rats. Melatonin counteracted the increased lipoperoxidation and nitric oxide, prevented decreased glutathione peroxidase and reductase activity, reduced the glutathione disulfide/glutathione (GSSG/GSH) ratio, and maintained the GSH pool. Furthermore, melatonin administration was associated with a reduction of apoptosis, which was increased in venom-injected rats. Overall, these results suggest that melatonin mitigates oxidative/nitrosative stress in venom-induced cardio-hepato-renal injury in rats. Our results suggest that melatonin treatment may ameliorate some of the effects of N. haje envenomation.

Antivenom activity of triterpenoid (C34H68O2) from Leucas aspera Linn. against Naja naja naja venom induced toxicity: antioxidant and histological study in mice

The isolated and identified triterpenoid, 1-hydroxytetratriacontane-4-one (C34H68O2), obtained from the methanolic leaf extract of Leucas aspera Linn. was explored for the first time for antisnake venom activity. The plant (L. aspera Linn.) extract significantly antagonized the spectacled cobra (Naja naja naja) venom induced lethal activity in a mouse model. It was compared with commercial antiserum obtained from King Institute of Preventive Medicine (Chennai, Tamil Nadu, India). N. naja naja venom induced a significant decrease in antioxidant superoxide dismutase, glutathione (GSH) peroxidase, catalase, reduced GSH and glutathione-S-transferase activities and increased lipid peroxidase (LPO) activity in different organs such as heart, liver, kidney and lungs. The histological changes following the antivenom treatment were also evaluated in all these organs. There were significant alterations in the histology. Triterpenoid from methanol extract of L. aspera Linn. at a dose level of 75 mg per mouse significantly attenuated (neutralized) the venom-induced antioxidant status and also the LPO activity in different organs.

Intraspecific variation in the venom of the vermivorous cone snail Conus vexillum

A combination of proteomic and biochemical assays was used to examine variations in the venom of Conus vexillum taken from two locations (Hurgada and Sharm El-Shaikh) in the Red Sea, Egypt. Using MALDI/TOF-MS, a remarkable degree of intra-species variation between venom samples from both locations was identified. To evaluate variability in the cytotoxic effects of Conus venom, mice were injected with the same dose from each location. The oxidative stress biomarkers [malondialdehyde (MDA), protein carbonyl content (PCC)], antioxidants [glutathione (GSH), superoxide dismutase (SOD), catalase (CAT)], total antioxidant capacity (TAC) and nitric oxide (NO), were measured 3, 6, 9 and 12h post venom injection. The venoms induced a significant increase in the levels of PCC, MDA, NO, GSH and CAT. The venoms significantly inhibited the activity of SOD and reduced the TAC. Toxicological data showed that the venom obtained from Hurgada was more potent than that obtained from Sharm El-Shaikh. It can be concluded that: (1) the venom of the same Conus species from different regions is highly diversified (2) the venoms from different locations reflect clear differences in venom potency and (3) the cytotoxic effects of C. vexillum venom can be attributed to its ability to induce oxidative stress.

Time-course of lipid peroxidation in different organs of mice treated with Echis pyramidum snake venom

This study examined the effect of Echis pyramidum (EP) venom on time-course of lipid peroxidation in different vital organs of mice. Adult male Swiss albino mice were injected with EP venom (2 mg/kg, i.p.); control mice received vehicle alone (normal saline). Mice were killed at 1, 3, 6, 12, and 24 h post-envenomation. The liver, lung, kidney, heart, and brain (cerebrum and cerebellum) were collected for the estimation of malondialdehyde (MDA), an index of lipid peroxidation. The results of this study showed that a single injection of EP venom caused a significant lipid peroxidation in all the organs studied. The onset of lipid peroxidation was as early as 1 h and persisted for several hours, suggesting an important role of oxidative stress in the cytotoxicity of EP venom.

Biochemical and histopathological alterations induced in rats by Tityus serrulatus scorpion venom and its major neurotoxin tityustoxin-I

Intravenous injection into the rat of sublethal doses of Tityus serrulatus scorpion venom (100 micrograms protein/kg) or its major neurotoxin tityustoxin-I (TsTX-I, 20 micrograms/kg) caused, 30-180 min after injection, statistically significant increases in the serum levels of aspartate aminotransferase, amylase, creatine kinase and lactate dehydrogenase, as well as hyperglycemia, a high level of plasma free fatty acids and a low level of liver glycogen. The in vitro serum levels of the above enzymes did not change. For alanine aminotransferase, gamma-glutamyl transferase and alkaline phosphatase, neither in vitro nor in vivo alterations were observed. The whole venom and TsTX-I caused hepatic congestion with hemolysis and hydropic degeneration. Other histological lesions included edema and congestion with subpleural hemorrhage in the lungs, hypertrophy of fibers with degeneration areas in the heart, and congestion and hemorrhage in the kidneys. In the salivary glands, alterations to the acini and ductules were visible. In the adrenal glands no morphological alterations could be detected at the studied doses. The results suggest that the in vivo enzymatic and histopathological alterations are due to tissue lesions evoked by the whole venom and TsTX-I. An indirect effect, however, induced by stimulation of acetylcholine and catecholamine release in the postganglionic nerve terminals, cannot be excluded.

Effect of scorpion Leiurus quinquestriatus (H&E) venom on the clinical chemistry parameters of the rat

Egyptian scorpion venom was collected by electrical stimulation of the telson. Rats were injected with the lyophilized venom in 3 different doses (100, 200 and 400 micrograms/kg). Blood samples were drawn by heart puncture before and 4 h after venom administration. Serum was separated and collected for determination of glucose, blood urea nitrogen (BUN), creatinine, uric acid (UA), total proteins, cholesterol, sodium, potassium, calcium, inorganic phosphorus, alkaline phosphatase, aspartate aminotransferase (AST, GOT), alanine aminotransferase (ALT, GPT), lactate dehydrogenase and creatine phosphokinase (CPK). Serum glucose, creatinine, GOT, GPT and LDH were increased significantly in all treatments. At the same time serum BUN and CPK were elevated significantly with a dose-response relationship. On the other hand, serum total proteins, uric acid, cholesterol, calcium and potassium were significantly decreased 4 h after administration of the 3 doses. These changes in clinical chemistry parameters are most probably related to the toxic effect of the venom on the target organs.

Are the toxicological effects of scorpion envenomation related to tissue venom concentration?

The pharmacokinetics of 125I-labelled Androctonus amoreuxi venom and its lethal fraction was studied in rabbits. Comparative pharmacokinetic studies of labelled A. amoreuxi, Leisurus quinquestriatus and Buthotus judaicus venoms were carried out in guinea-pigs. The pharmacokinetics of A. amoreuxi venom was also studied in rats. Groups of rats were injected with labelled A. amoreuxi venom and killed at frequent time intervals for the determination of the relative tissue venom concentration as a function of time. Several groups of rabbits were injected with A. amoreuxi venom and serial blood samples withdrawn at time intervals comparable with those used in the pharmacokinetic studies for the determination of serum glucose, insulin, cortisol, total proteins, albumin, globulins, cholesterol, total bilirubin, urea, uric acid, bicarbonate, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, sodium, potassium, calcium and phosphorus. The packed cell volume, and total and differential leucocyte counts were also determined. In another series of experiments continuous monitoring of the electrocardiograms of rabbits following venom injection was made to correlate any abnormalities with tissue venom concentration. All three venoms and the lethal fraction showed an open two-compartment behaviour with rapid distribution half-lives ranging between 4 and 7 min and overall elimination half-lives of 4.2 to 13.4 hr. The behaviour of A. amoreuxi venom was not markedly different in the three species of animals used. In a given species (guinea-pigs) the behaviour of the three venoms was not markedly different. Correlation of the ECG changes with cardiac venom concentration showed that arrhythmias and infarction occurred at times when cardiac concentration was very low, indicating that the cardiac abnormalities might result from indirect factors. Comparison of the course of the biochemical changes with venom concentration in the central compartment indicated that the site of action of the venom is not located in the central compartment. Correlation of the intensity of the biochemical effects with venom concentration in the peripheral compartment revealed an apparent delay in the onset and peak of action. This was explained by assuming that the tissue compartment could be divided into a rapidly accessible and a slowly accessible compartment with the venom acting through the slowly accessible compartment. There was also the possibility of the venom acting indirectly through the release of other substances or transformation to an intermediate.(ABSTRACT TRUNCATED AT 400 WORDS)