Nephrotoxicity of mercuric chloride, methylmercury and cinnabar-containing Zhu-Sha-An-Shen-Wan in rats

Abstract

Cinnabar (HgS) is used in traditional medicines, and total Hg content is used for risk assessment of cinnabar-containing traditional medicines such as Zhu-Sha-An-Shen-Wan (ZSASW). Is ZSASW or cinnabar toxicologically similar to common mercurials? Adult Sprague–Dawley rats were gavaged with ZSASW (1.4 g/kg), cinnabar (0.2 g/kg), HgCl 2 (0.02 g/kg), MeHg (0.001 g/kg), or saline daily for 60 days, and toxicity was determined. Animal body-weight gain was decreased by HgCl 2 and MeHg. Blood urea nitrogen (BUN) was increased by MeHg. Histology showed severe kidney injury following MeHg and HgCl 2 treatments, but mild after ZSASW and cinnabar. Renal Hg contents were markedly increased in the HgCl 2 and MeHg groups but were not elevated in the ZSASW and cinnabar groups. The expression of kidney injury molecule-1 was increased 50-fold by MeHg, 4-fold by HgCl 2, but was unaltered by ZSASW and cinnabar; the expression of matrilysin was increased 3-fold by MeHg. In contrast, the expression of N-cadherin was decreased by HgCl 2. Thus, ZSASW and cinnabar are much less nephrotoxic than HgCl 2 and MeHg, indicating that chemical forms of mercury underlie their disposition and toxicity.