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 SO 2 residues may be toxic. We compared effects of sulfur-free versus sulfurfumigated 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.

Impact of Sulfur Fumigation on the Chemistry of Dioscoreae Rhizoma (Chinese Yam)

“… 49 In addition, tryptophan can be related to the hydroxyl radical-scavenging activity of DR. 50 Reduction of tryptophan caused by sulfur fumigation may affect the synthesis of key biomolecules and scavenging power on free radicals, thus various nutritional functions of DR (e.g., anti-inflammatory, antioxidant, and antidepressant effect) can be influenced. 5 Furthermore, the toxicity and bioactivity of tryptophan sulfonate, the sulfur-containing derivative of tryptophan in S-DR, are still unknown. Another example is polysaccharides.…”

“…However, it has been found that the sulfur fumigation weakens the healthcare functions of DR, and, even worse, the consumption of sulfur-fumigated DR (S-DR) may be related to hepatotoxicity and nephrotoxicity. 4 , 5 These findings indicate that sulfur fumigation changes the chemical profiles of DR qualitatively and/or quantitatively. Indeed, this indication is supported by previous studies, in which sulfur fumigation was found to affect the physicochemical properties of starch and the total contents of aromatic components in DR. For instance, the solubility of starch was found to be higher in S-DR samples than that of nonfumigated DR (NS-DR) samples, and the total flavones were more abundant in S-DR samples than those in air-dried DR samples.…”

“…In recent decades, sulfur fumigation has been commonly used for the post-harvest processing of DR to prevent pest infestation, mold, and bacterial contamination and to give it a more attractive, whiter appearance. However, it has been found that the sulfur fumigation weakens the healthcare functions of DR, and, even worse, the consumption of sulfur-fumigated DR (S-DR) may be related to hepatotoxicity and nephrotoxicity. , These findings indicate that sulfur fumigation changes the chemical profiles of DR qualitatively and/or quantitatively. Indeed, this indication is supported by previous studies, in which sulfur fumigation was found to affect the physicochemical properties of starch and the total contents of aromatic components in DR. For instance, the solubility of starch was found to be higher in S-DR samples than that of nonfumigated DR (NS-DR) samples, and the total flavones were more abundant in S-DR samples than those in air-dried DR samples. , Nevertheless, the exact impacts of sulfur fumigation on the chemical profile of DR as well as the molecular and cellular mechanisms involved, both of which are necessary to thoroughly understand how sulfur fumigation impairs the nutritional value of DR, remain to be investigated.…”