Lead Organ and Tissue Toxicity: Roles of Mitigating Agents (Part 1)

Abstract

Lead is one of the metals whose toxicological effect in humans and animals is of clinical concerned as reported by researchers. Quite a number of chemical agents have been reported to ameliorate lead associated toxicological effects especially in animal studies. This literary study reviewed reported toxicological effect of lead on the liver, kidney and brain with emphasis on the roles of mitigating chemical agents. In this review it was observed that his to patho logical changes in lead associated he patotoxicity include hepatomegaly with necrosis, formation of hyper plastic nodules and presence of in tranu clear inclusion bodies within hepatocytes. In the kidney reports revealed various degenerative changes with focal tubular necrosis invaded by inflammatory cells in cortical renal tubules, diminution in the amount of filtration slits, apoptosis in epithelial cells of the glomeruli, increase in lysosomal structures, pinocytic vesicles and large mitochondria in proximal tubule cells. Lead altered mRNA levels of the following apoptotic and neurotrophic factors: caspase 2 and 3 and brain-derived neurotrophic factor in the brain. Histopathological changes occurred in gray matter, anterior cingulate cortex, hippocampus and cerebellum of treated animals. Lead exposure altered biomarkers of liver, kidney and brain function with increased lipid peroxidation and decrease antioxidants function. Lead induced toxicities were observed to be mitigated by vitamin C, vitamin E, calcium, magnesium dimercaptosuccinic acid, calcium disodium ethyl diaminetetra acetic acid and selenium. Extracts of plant origin and chemical substances of animal origin were also reported to mitigate these toxicities. One of the commonly reported mechanisms associated with lead toxicological effect is the generation of Reactive Oxygen Species in organs and tissues this may be supported by the mitigating effect of some antioxidants on lead toxicological effects.

Hepatoprotective Effect of Sesame Oil against Lead Induced Liver Damage in Albino Mice: Histological and Biochemical Studies

“…Several reports have indicated that lead can cause neurological, hematological, gastrointestinal, reproductive, circulatory and immunological pathologies, all of them related to the dose and the duration of time of lead exposure [9 &10]. Toxicities due to lead exposure have been attributed to the ability of lead to induce oxidative stress through the generation of reactive oxygen species [11].…”

“…Plant extracts and materials of animal origin were also observed to protect against lead induced toxicity in experimental animals. The abilities of these extracts to mitigate these toxicities were attributed to the antioxidant properties of principles contained in these extracts [11].…”

Amelioration of Gentamicin-Induced Renal Damage in Rats by Ethanol Extract of the Whole Plant Biophytum Sensitivum (Linn.) Dc

“…Exposure of human body to toxic substances may affect multiple organ systems and cause morphological, biochemical and physiological changes, including impaired kidney function and haematological disorders [36][37][38]. Hematopoietic system is the main target of some drug which adversely affects heme synthesis enzymes, the normal production rate of erythropoietin, normal range, morphology and distribution of various blood cells [39,40]. Toxic drugs damage erythrocyte and affect its oxygen-carrying capacity thereby increase the risk of developing hypertension and cardiac arrest [41].…”

Effect of aqueous seed extract of <i>Nigella sativa</i> on lead-induced cerebral cortex toxicity in Long Evans rats

“…Al-Naggar et al (2003) reported that N. sativa can prevent the damage of spatial memory after scopolamine administration and reduced the acetylcholinesterase (AChE) activity as well as oxidative stress of the brain tissue in rats (Hosseini et al, 2015). Researches using animal models have shown that lead toxicity could be associated with oxidative stress via the generation of reactive oxygen species and can be mitigated by some antioxidants, materials of animal origin and extracts of plant origin (Adikwu et al, 2013). The present findings agree to the fact that natural compounds that are rich in antioxidants help to reduce oxidative stress thus alleviating the effect of oxidative agents (Ahamed and Siddiqui, 2007).…”