Effect of sulfur-fumigated Rhizoma dioscoreae on organ morphology and function in rats

Abstract

Objective: Sulfur fumigation is used to preserve Rhizoma Dioscoreae (RD), a traditional medicinal herb, but excess consumption of SO2 residues may be toxic. We compared effects of sulfur-free versus sulfur-fumigated RD concentrated aqueous extracts on rat blood biochemistry and organ morphology. Methods: Rats were randomly divided to receive sulfur-fumigated RD or sulfur-free RD aqueous extract (20 g/kg, intragastric, 90 d) or distilled water (control). Body weight and food intake were recorded weekly. Blood samples were collected 12 h after final administration and histopathological examinations performed. Results: Body weight did not differ among groups (P>0.05). Blood Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), Total Cholesterol (TC), and Glucose (GLU) were lower in the sulfur-free group versus controls (P<0.05). GLU and TC were also reduced but AST and ALT elevated in the sulfur-fumigated group. In the sulfur-fumigated group, organ coefficients for lung and thymus (P<0.05) as well as spleen and kidney (P<0.01) were higher than controls. In the sulfur-free group, only thymus organ coefficient was significantly greater than control (P<0.05). Histopathology revealed multiple focal fatty infiltrations in duodenum muscle (two rats) and punctate liver necrosis (four rats) in the sulfur-fumigated group. Conclusion: Long-term sulfur-fumigated RD consumption may cause liver damage.