Oxidative stress biomarkers in some rat brain structures and peripheral organs underwent cocaine

Oxidative stress (OS) generates or intensifies cocaine-evoked toxicity in the brain and peripheral organs. The aim of this study was to examine superoxide dismutase (SOD) activity and lipid peroxidation [measured by malondialdehyde (MDA) levels] in rats during maintenance of cocaine self-administration and after withdrawal by a yoked-triad procedure. Our results indicate that repeated cocaine self-administration provoked an elevation of SOD activity in the hippocampus, frontal cortex, dorsal striatum, and liver. MDA levels were reduced in the brain, increased in the liver, kidney, and heart during maintenance of self-administration, and increased in the kidney in cocaine-yoked rats. In addition, following extinction training, we found enhanced MDA levels and SOD activity in the rat hippocampus, while changes in the activity of OS biomarkers in other brain structures and peripheral tissues were reminiscent of the changes seen during cocaine self-administration. These findings highlight the association between OS biomarkers in motivational processes related to voluntary cocaine intake in rats. OS participates in memory and learning impairments that could be involved in drug toxicity and addiction mechanisms. Therefore, further studies are necessary to address protective mechanisms against cocaine-induced brain and peripheral tissue damage

Toksykologiczne aspekty zanieczyszczeń metalicznych w kosmetykach

Heavy metal compounds are included in many cosmetics and dietary supplements. The most frequent metal contaminants of cosmetic products are mercury, lead, cadmium and arsenic. The contents of toxic metals in cosmetic products are mainly associated with the use of inadequately cleaned raw materials. Despite numerous inspections of the manufacturing process andkeeping the production in line with the principles of Good Manufacturing Practice (GMP), these elements are still found even in products of the best quality. Metals contaminate cosmetics as a result of production processes. Heavy metal toxicity is the result of prolonged exposure which causes the appearance of many side effects. The mechanism of toxicity is mainly related to the impairment of ATP and the change of protein synthesis in enzyme activity, by inducing free radicals. Metals interfere with, among others, the proper functioning of organs, neurotoxic effects, cause problems in learning and behavior, adversely affect the proper functioning of the immune system and adversely affect the developping fetus. Metals have the ability to accumulate in certain organs, primarily in the kidneys and the liver. The European Union does not regulate the limits of metal concentrations in detail, but there is a list of substances prohibited for use in cosmetics in all Member States