Cardiopulmonary complications induced by Iranian Mesobuthus eupeus scorpion venom in anesthetized rabbits

Scorpion envenomation is a life-threatening condition, especially in children and elderly individuals affected by respiratory and cardiovascular diseases. In this study, the toxic effects of median lethal dose (LD50) injections of Mesobuthus eupeus (Me) venom on the heart and lungs of anesthetized rabbits were investigated. Six rabbits were selected and alterations in their electrocardiogram, heart rate, respiration and blood pressure before and after venom injection were recorded. Cardiac troponin T (cTnT), creatinine kinase muscle-brain fraction (CK-MB) and lactate dehydrogenase (LDH) were measured at 0, 1 and 3 hours after envenomation and pathology studies were carried out postmortem. All the animals showed signs and symptoms of envenomation within 40 minutes and died 3 to 3.5 hours after venom injection. Pathology studies revealed alveolar edema in 100 percent of the rabbits and myocardial infarction in 16 percent. The main histopathological changes were myocytolysis, coagulation necrosis, focal hemorrhage, thrombus formation both in myocardium and on endocardial surfaces as well as inflammatory infiltrates in the heart and hemorrhage, vascular thrombus and interstitial inflammation in the lungs. ECG monitoring of rabbits showed ST elevation, ST depression and inverted T and Q waves. In addition, although cTnT levels increased in 16 percent of the animals and serum LDH was also augmented, none of these changes was statistically significant. The enzyme CK-MB also did not show any change after Me venom injection. In conclusion, the results of this study showed that Me venom killed animals in less than 3.5 hours through severe pulmonary damage and it appears that the deaths could not be attributed to cardiovascular lesions. Therefore, Me venom effects on the lungs are so important that they appear to be independent of heart damage.(AU)

Purification and partial characterization of a coagulant serine protease from the venom of the Iranian snake Agkistrodon halys

Agkistrodon halys is one of several dangerous snake species in Iran. Among the most important signs and symptoms in patients envenomated by this snake is disseminated intravascular coagulation. A thrombin-like enzyme, called AH143, was isolated from Agkistrodon halys venom by gel filtration on a Sephadex G-50 column, ion-exchange chromatography on a DEAE-Sepharose and high performance liquid chromatography (HPLC) on a C18 column. In the final stage of purification, 0.82 mg of purified enzyme was obtained from 182.5 mg of venom. The purified enzyme showed a single protein band by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), under reducing conditions, and its molecular mass was found to be about 30 kDa. AH143 revealed clotting activity in human plasma, which was not inhibited by EDTA or heparin. This enzyme still demonstrated coagulation activity when exposed to variations in temperature and pH ranging, respectively, from 30 to 40°C and from 7.0 to 8.0. It also displayed proteolytic activities on synthetic substrate. The purified enzyme did not show any effect on casein. We concluded that the venom of the Iranian snake Agkistrodon halys contains about 0.45 percent single procoagulant protein which appears to be a thrombin-like enzyme.(AU)

Cytotoxic effect of ICD-85 (venom-derived peptides) on MDA-MB-231 cell line

Since 1987, when chemopreventive testing programs began, more than 1,000 agents and agent combinations have been selected and evaluated in preclinical studies of chemopreventive activity against various types of cancers. In the present study we aimed to provide quantitative and qualitative characterization of biological and pharmacological activities of ICD-85 on MDA-MB-231 cell line (a highly invasive breast cancer cell line) in order to gain a better understanding of the cytotoxic and apoptotic effects of this compound. For this study, the MDA-MB-231 cell line was used and the effect of ICD-85 was assayed by measuring the activity of the cytosolic enzyme lactate dehydrogenase (LDH), released into the culture medium after membrane damage. Morphological alterations of cells were investigated in the control group and cells incubated with ICD-85 as cytotoxic agent. Results showed, in the test group, that cells incubated with 16 µg/mL of ICD-85 had decreased cytoplasmic branching. Some cells were had ruptured and lost the continuity of their surrounding membranes while some had shrunk. Cells incubated with higher doses (above16 µg/mL) showed similar changes towards cellular normality with more severity. Results obtained from the ICD-85 stability test reveal that the effect of ICD-85 on MDA-MB-231 cell line in culture medium is stable throughout the incubation time period (24 hours). It appears that ICD-85 at higher concentrations acts at the membrane level, which allows the passage of ions down the concentration gradient, resulting in osmotic changes in organelles followed by several unidentified mechanisms leading to cell death. At lower concentrations, it appears that ICD-85 can prevent cell growth by another mechanism, which may be one of the causes for apoptosis in the cell line.(AU)