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

Abstract Thimerosal is an organomercurial compound, which is used in the preparation of intramuscular immunoglobulin, antivenoms, tattoo inks, skin test antigens, nasal products, ophthalmic drops, and vaccines as a preservative. In most of animal species and humans, the kidney is one of the main sites for mercurial compounds deposition and target organs for toxicity. So, the current research was intended to assess the thimerosal induced nephrotoxicity in male rats. Twenty-four adult male albino rats were categorized into four groups. The first group was a control group. Rats of Group-II, Group-III, and Group-IV were administered with 0.5µg/kg, 10µg/kg, and 50µg/kg of thimerosal once a day, respectively. Thimerosal administration significantly decreased the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione reductase (GR), glutathione (GSH), and protein content while increased the thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) levels dose-dependently. Blood urea nitrogen (BUN), creatinine, urobilinogen, urinary proteins, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels were substantially increased. In contrast, urinary albumin and creatinine clearance was reduced dose-dependently in thimerosal treated groups. The results demonstrated that thimerosal significantly increased the inflammation indicators including nuclear factor kappaB (NF-κB), tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6) levels and cyclooxygenase-2 (COX-2) activities, DNA and histopathological damages dose-dependently. So, the present findings ascertained that thimerosal exerted nephrotoxicity in male albino rats. Resumo O timerosal é um composto organomercurial, utilizado na preparação de imunoglobulina intramuscular, antivenenos, tintas de tatuagem, antígenos de teste cutâneo, produtos nasais, gotas oftálmicas e vacinas como conservante. Na maioria das espécies animais e nos humanos, o rim é um dos principais locais de deposição de compostos de mercúrio e órgãos-alvo de toxicidade. Assim, a presente pesquisa teve como objetivo avaliar a nefrotoxicidade induzida pelo timerosal em ratos machos. Vinte e quatro ratos albinos machos adultos foram categorizados em quatro grupos. O primeiro grupo era um grupo de controle. Ratos do Grupo II, Grupo III e Grupo IV receberam 0,5µg / kg, 10µg / kg e 50µg / kg de timerosal uma vez ao dia, respectivamente. A adm