Conus vexillum venom induces oxidative stress in Ehrlich's ascites carcinoma cells: an insight into the mechanism of induction

Background: It is estimated that venoms of marine cone snails (genus Conus) contain more than 100,000 different small peptides with a wide range of pharmacological and biological actions. Some of these peptides were developed into potential therapeutic agents and as molecular tools to understand biological functions of nervous and cardiovascular systems. In this study we examined the cytotoxic and anticancer properties of the marine vermivorous cone snail Conus vexillum (collected from Hurgada and Sharm El-Shaikh, Red Sea, Egypt) and suggest the possible mechanisms involved. The in vitro cytotoxic effects of Conus venom were assessed against Ehrlich's ascites carcinoma (EAC) cells. Results: Conus venom treatment resulted in concentration-dependent cytotoxicity as indicated by a lactate dehydrogenase leakage assay. Apoptotic effects were measured in vivo by measuring levels of reactive oxygen species and oxidative defense agents in albino mice injected with EAC cells. Conus venom (1.25 mg/kg) induced a significant increase (p < 0.05) in several oxidative stress biomarkers (lipid peroxidation, protein carbonyl content and reactive nitrogen intermediates) of EAC cells after 3, 6, 9 and 12 hours of venom injection. Conus venom significantly reduced (p < 0.05) the activities of oxidative defense enzymes (catalase and superoxide dismutase) as well as the total antioxidant capacity of EAC cells, as evidenced by lowered levels of reduced glutathione. Conclusions: These results demonstrate the cytotoxic potential of C. vexillum venom by inducing oxidative stress mediated mechanisms in tumor cells and suggest that the venom contains novel molecules with potential anticancer activity.(AU)

Conus vexillum venom induces oxidative stress in Ehrlich's ascites carcinoma cells: an insight into the mechanism of induction

It is estimated that venoms of marine cone snails (genus Conus) contain more than 100,000 different small peptides with a wide range of pharmacological and biological actions. Some of these peptides were developed into potential therapeutic agents and as molecular tools to understand biological functions of nervous and cardiovascular systems. In this study we examined the cytotoxic and anticancer properties of the marine vermivorous cone snail Conus vexillum (collected from Hurgada and Sharm El-Shaikh, Red Sea, Egypt) and suggest the possible mechanisms involved. The in vitro cytotoxic effects of Conus venom were assessed against Ehrlich’s ascites carcinoma (EAC) cells. Results Conus venom treatment resulted in concentration-dependent cytotoxicity as indicated by a lactate dehydrogenase leakage assay. Apoptotic effects were measured in vivo by measuring levels of reactive oxygen species and oxidative defense agents in albino mice injected with EAC cells. Conus venom (1.25 mg/kg) induced a significant increase ( p  < 0.05) in several oxidative stress biomarkers (lipid peroxidation, protein carbonyl content and reactive nitrogen intermediates) of EAC cells after 3, 6, 9 and 12 hours of venom injection. Conus venom significantly reduced ( p  < 0.05) the activities of oxidative defense enzymes (catalase and superoxide dismutase) as well as the total antioxidant capacity of EAC cells, as evidenced by lowered levels of reduced glutathione.Conclusions These results demonstrate the cytotoxic potential of C. vexillum venom by inducing oxidative stress mediated mechanisms in tumor cells and suggest that the venom contains novel.

Risk factors of childhood tuberculosis: a case control study from rural Bangladesh

Background: Childhood tuberculosis (TB) is one of the major causes of childhood morbidity and mortality; however, it is relatively a neglected disease. Hence, we explored the risk factors for childhood TB. Methods: Ninty-five cases and 94 controls were selected during January to May 2011 from DOTS centres located in four sub-districts of Bangladesh. The exposure status of recently diagnosed childhood TB patients (<18-year-olds), who were sputum-positive, were compared with children who were sent to the laboratory with suspected tuberculosis but were found to be sputum-negative. Data were collected by a structured questionnaire. Crude odds ratios (OR), adjusted odds ratio (AOR) and 95% confidence intervals (CI) were estimated. Stepwise logistic regression model was used to identify independent predictors. Results: Children under 14 years of age (AOR: 0.25; 95% CI: 0.10-0.66), having completed primary education (AOR: 0.28; 95% CI: 0.10-0.74), whose fathers’ were in business or service(AOR: 0.24; 95% CI: 0.08-0.72), and who slept in a less crowded room (AOR: 0.32; 95% CI:0.14-0.76), lived in a house with a separate kitchen (AOR: 0.39; 95% CI: 0.16-0.96) had less chance of having TB. Those who had contact with cases of TB among relatives or neighbours were less likely to have TB (AOR: 0.28; 95% CI: 0.16-0.70) compared to those who had contact with a TB case in the family. Conclusion: Age, education, father’s occupation, crowding, kitchen location and intimate contact with a TB case were significantly associated with smear-positive childhood TB.