A study on the potential reprotoxic effects of thimerosal in male albino rats

Abstract

Thimerosal is ethyl mercury based compound which is being used as a preservative in vaccines since decades. Pharmaceutical products and vaccines that contain thimerosal are among the potential source of mercury exposure. Current research was intended to ascertain the reprotoxic effects of thimerosal on rat testes. Twenty-four adult male albino rats were sorted into four groups (n = 6). The first group was a control group. Rats of experimental Group 2, 3 and 4 were treated with various dosages of thimerosal (0.5, 10, 50 mg/kg) respectively. Rats were decapitated after thirty days of trial and different parameters were analyzed. Thimerosal exposure resulted in a significant decrease in antioxidant enzyme activities including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), glutathione reductase (GSR) and increased levels of thiobarbituric acid reactive substances (TBARS). Different doses of thimerosal significantly decreased (p < 0.05) the concentration of plasma testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH). Additionally, Daily sperm production (DSP) and efficiency of daily sperm production were significantly reduced followed by thimerosal exposure. Moreover, thimerosal significantly (p < 0.05) decreased the primary spermatocytes, secondary spermatocytes, number of spermatogonia along with spermatids. Thimerosal induced adverse histopathological and morphological changes in testicular tissues such as decreased Leydig cells, diameter of seminiferous tubules, tunica albuginea height and epithelial height. On the other hand, the increase in tubular lumen and interstitial spaces was observed due to thimerosal. These outcomes indicated that thimerosal has potential reprotoxic effects in male albino rats.

Toxicological effects of thimerosal on rat kidney: a histological and biochemical study

“…Capillaries interacted with tubules were dilated and dilation of tubules was also observed in the inner medulla. Animals treated with thimerosal showed damage in tissues in the form of tubular dilation and lesions, which is in line with a previous study conducted on testicular tissues by Ijaz et al (2020). Augmented KIM-1 and NGAL levels also endorse histopathological damages.…”

“…Anti-oxidant enzymes, including CAT, SOD, POD, and GR perform a major role in the intracellular defense against cell damages by free radicals (Lobo et al, 2010). A recent study reported that thimerosal administration led to a dose-dependent reduction in the enzyme activities in rat testes (Ijaz et al, 2020). So, it can be speculated that mercury in the Et-Hg is the primary reason behind the increase in oxidative stress, which led to a decrease in antioxidant enzyme activity and increased lipid peroxidation.…”