A possible mechanism of resistance to cadmium toxicity in male Long-Evans rats

Effect of cadmium on the regulatory mechanism of steroidogenic pathway of Leydig cells during spermatogenesis

Cadmium is a male reproductive toxicant that interacts with a variety of pathogenetic mechanisms. However, the effect of cadmium on the regulatory mechanism of the steroidogenic pathway of Leydig cells during spermatogenesis is still ambiguous. Light microscopy, Western blot, immunohistochemistry, immunofluorescence, and quantitative polymerase chain reaction were performed to study the regulatory mechanism of the steroidogenic pathway of Leydig cells during spermatogenesis. The results indicated that in the control group, Leydig cells showed dynamic immunoreactivity and immunosignaling action with a strong positive significant secretion of 3β-hydroxysteroid hydrogenase (3β-HSD) in the interstitial compartment of the testis. Leydig cells showed a high active regulator mechanism of the steroidogenic pathway with increased the proteins and genes expression level of steroidogenic acute regulatory protein (STAR), cytochrome P450 cholesterol (CYP11A1), cytochrome P450 cholesterol (CYP17A1), 3β-hydroxysteroid hydrogenase (3β-HSD) 17β-hydroxysteroid hydrogenase (17β-HSD), and androgen receptor (AR) that maintained the healthy and vigorous progressive motile spermatozoa. However, on treatment with cadmium, Leydig cells were irregularly dispersed in the interstitial compartment of the testis. Leydig cells showed reduced immunoreactivity and immunosignaling of 3β-HSD protein. Meanwhile, cadmium impaired the regulatory mechanism of the steroidogenic process of the Leydig cells with reduced protein and gene expression levels of STAR, CYP11A1, CYP17A1, 3β-HSD, 17β-HSD, and AR in the testis. Additionally, treatment with cadmium impaired the serum LH, FSH, and testosterone levels in blood as compared to control. This study explores the hazardous effect of cadmium on the regulatory mechanism of the steroidogenic pathway of Leydig cells during spermatogenesis.

Phenolic compounds analysis, antioxidant, and hepatoprotective effects of Periploca angustifolia extract on cadmium-induced oxidative damage in HepG2 cell line and rats

A total of five components (Catechin, Caffeic acid, Ferulic acid, Rosmarinic acid, and Amentoflavone) were identified in Periploca angustifolia leaf methanolic extract. This extract did not cause any cytotoxic effect on HepG2 cell line within the range of concentrations tested (0-400 µg mL^-1). Thus, pre-treatment with 100 µg mL^-1 of P. angustifolia leaf methanolic extract (PAE) significantly (p < .05) protective HepG2 cells against cytotoxicity induced by cadmium exposure. However, Cd-intoxication significantly (p < .05) increased alanine and aspartate amino transferases serum activities (ALT and AST) and bilirubin content by 1.85-, 1.13-, and 3.55-fold, respectively. The levels of hepatic antioxidant parameters including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were significantly (p < .05) decreased in Cd-intoxicated rats with concomitant enhancement of lipid peroxidation. Our results showed that P. angustifolia leaf methanolic extract can induce antioxidant effects and also exerts beneficial effects for the treatment of Cd-induced hepatotoxicity.

Toxicity of cadmium and its health risks from leafy vegetable consumption

Cadmium (Cd) is a highly toxic heavy metal and has spread widely in the environment in recent decades. This review summarizes current knowledge about Cd contamination of leafy vegetables, its toxicity, exposure, health risks, and approaches to reducing its toxicity in humans. Leafy vegetable consumption has been identified as a dominant exposure pathway of Cd in the human body. An overview of Cd pollution in leafy vegetables as well as the main sources of Cd is given. Notable estimated daily intakes and health risks of Cd exposure through vegetable consumption for humans are revealed in occupational exposure areas and even in some reference areas. Vegetable consumption is one of the most significant sources of exposure to Cd, particularly in occupational exposure regions. Therefore, numerous approaches have been developed to minimize the accumulation of Cd in leafy vegetables, among which the breeding of Cd pollution-safe cultivars is one of the most effective tools. Furthermore, dietary supplements from leafy vegetables perform positive roles in alleviating Cd toxicity in humans with regard to the effects of essential mineral elements, vitamins and phytochemicals taken into the human body via leafy vegetable consumption.

Protective effect of grape seed extract against cadmium-induced testicular dysfunction

Cadmium (Cd) is the most prevalent toxic metal present in livestock feed; therefore, the present study aimed to examine the ameliorative effects of grape seed extract (GSE) on cadmium chloride (CdCl₂)-induced testicular dysfunction of Wistar rats. Male adult Wistar rats (40 rats; n=10/group) were divided into four equal groups. Group one was used as a control, and was given ad libitum access to food and water. Groups 2–4 were treated with CdCl₂ [5 mg/kg body weight (BW)], GSE (400 mg/kg BW, orally), and GSE plus CdCl₂, respectively. Blood and testicular tissues were collected and assayed for biochemical and histopathological changes, respectively. Testicular genes were expressed using semi-quantitative RT-PCR analysis. The results of the present study demonstrated that there was a decrease in serum testosterone levels following CdCl₂ toxicity, which were normalized after GSE co-administration. Furthermore, CdCl₂ significantly increased the serum levels of malondialdehyde, and decreased levels of antioxidants. At the histopathological level, the testes of the CdCl₂ group exhibited congestion, edema in the interstitial blood vessels, irregular arrangement of the epithelial lining of the seminiferous tubules, and degeneration and sloughing of the spermatogenic cells, which accumulated in the center of the seminiferous tubules. Such pathological alterations were ameliorated following treatment with GSE in the CdCl₂ plus GSE group. The immunohistochemical expression of B-cell lymphoma 2-associated X protein was high in the CdCl₂ group, and low in the control and GSE groups. Co-treatment with GSE and CdCl₂ exhibited ameliorative effects on the immunoreactivity of B-cell lymphoma 2-associated X protein. CdCl₂ toxicity induced a significant downregulation in the mRNA expression levels of cytochrome P450 cholesterol side-chain cleavage enzyme, cytochrome P450 17A1, 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-HSD, androgen receptor, steroidogenic acute regulatory protein, and follicle-stimulating hormone receptor. GSE administration exhibited a stimulatory effect on steroidogenesis-associated enzymes, and co-treatment with GSE and CdCl₂ normalized and upregulated the mRNA expression levels of these examined genes. This study concluded that GSE has beneficial protective effects against the deleterious effects of CdCl₂ on the testis.

Induction of DNA double-strand breaks in the H4IIE cell line exposed to environmentally relevant concentrations of copper, cadmium, and zinc, singly and in combinations

Xenobiotics, including heavy metals, exist in nature as complex mixtures of compounds with possible interactions. Induction of DNA damage such as DNA strand breaks may exert detrimental consequences to both individuals and populations. In this study, the induction of DNA double-strand breaks was assessed using the H4IIE rat hepatoma cell line following exposure to high and environmentally relevant concentrations of chloride salts of the metals cadmium (Cd), copper (Cu), and zinc (Zn), both singly and in combination. DNA strand break analysis was performed using agarose gel electrophoresis. Median molecular lengths were calculated from fragment size distributions acquired from gel image data and were used as a quantitative measure of DNA double-strand break induction. Exposure to high concentrations of Cu and Cd in combination produced a significant increase in the occurrence of DNA strand break. However, exposing cells to high concentrations of Cu, Cd, and Zn in combination resulted in significantly lower DNA double-strand break compared to control cells. Addition of low Zn to the Cd/Cu mixture restored DNA damage level back to that of the control. Environmentally relevant concentrations of Cd, Cu, and Zn did not appear to induce DNA strand breaks in the H4IIE cell line.