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Background: Epidemiologic studies indicate that early life arsenic exposures are linked to an increased risk of cardiovascular diseases. Different oxidation and methylation states of arsenic exist in the environment and are formed in vivo via the action of arsenic (+3 oxidation state) methyltransferase (As3MT). Methylated arsenicals are pro-atherogenic postnatally, but pre- and perinatal effects are unclear. This is particularly important because methylated arsenicals are known to cross the placenta. Objectives: We tested the effects of early life exposure to inorganic and methylated arsenicals on atherosclerotic plaque formation and its composition in apolipoprotein E knock-out (apoE−/−) mice and evaluated whether apoE−/− mice lacking As3MT expression were susceptible to this effect. Methods: We exposed apoE−/− or apoE−/−/As3MT−/− mice to 200 ppb inorganic or methylated arsenic in the drinking water from conception to weaning and assessed atherosclerotic plaques in the offspring at 18 wk of age. Mixed regression models were used to estimate the mean difference in each outcome relative to controls, adjusting for sex and including a random effects term to account for within-litter clustering. Results: Early life exposure to inorganic arsenic, and more profoundly methylated arsenicals, resulted in significantly larger plaques in the aortic arch and sinus in both sexes. Lipid levels in these plaques were higher without a substantial difference in macrophage numbers. Smooth muscle cell content was not altered, but collagen content was lower. Importantly, there were sex-specific differences in these observations, where males had higher lipids and lower collagen in the plaque, but females did not. In mice lacking As3MT, arsenic did not alter the plaque size, although the size was highly variable. In addition, control apoE−/−/As3MT−/− mice had significantly larger plaque size compared with control apoE−/−. Conclusion: This study shows that early life exposure to inorganic and methylated arsenicals is pro-atherogenic with sex-specific differences in plaque composition and a potential role for As3MT in mice. https://doi.org/10.1289/EHP8171

Arsenic exposure increases the risk of atherosclerosis, the gradual occlusion of the large arteries with fibro-fatty plaque. While epidemiologic data provide convincing evidence this is true at higher exposures, it is unclear whether this may occur at low arsenic exposures, near the maximum contaminant level of 10 ppb. We have previously shown that 200 ppb arsenite in the drinking water increased the atherosclerosis in apolipoprotein E knock-out (apoE-/-) mice after 13 weeks, but the effects of lower concentrations were unknown. Therefore, here, we analyzed the effects of oral exposure to arsenite from 10 to 200 ppb after 13 weeks. Importantly, we found that even at the lowest concentration of arsenite, there was a significant increase in atherosclerotic plaque size. In our previous studies, we found that arsenite exposure resulted in decreased smooth muscle cells (SMCs) and collagen within the plaque. This change is indicative of a less stable phenotype that could increase the risk of rupture and subsequently, myocardial infarct or stroke in humans. In addition, we observed that lipid increased within the plaque without concomitant increase in macrophage content, suggesting that the macrophages were retaining more lipid intracellularly. We also assessed these plaque components in apoE-/- mice exposed to 10-200 ppb arsenite. Interestingly, we observed that macrophage lipid accumulation occurred at lower concentrations than the decreased SMC/collagen content. Together these data suggest that in the apoE-/- model, low arsenite concentrations are pro-atherogenic and that macrophage lipid homeostasis is more sensitive to arsenite-induced perturbation than the SMCs.

Effect of various surface sterilisation treatments on medicinal plants Salvadora persica andSolanum surattense has been studied for in-vitro propagation. Surface sterilisation treatment was appliedby physical, chemical and physiochemical means. Chemical sterilisation was done with sodium hypochlorite,physically with sonication and physiochemically with combination of both. Sodium hypochlorite alonewas found to be effective for smooth textured plant i.e., Salvadora persica, whereas for rough texturedplant Solanum surattense a combination of both physiochemical means yielded good results. However,sonication alone did not render the effective way of surface sterilisation. Moreover, for Salvadora persica,10% sodium hypochlorite was effective in eliminating bacterial or fungal growth whereas in Solanumsurattense, a concentration of 15% sodium hypochlorite proved to be effective. In general, best resultswere achieved in the combined treatment by physiochemical means.