S-methyl cysteine sulfoxide mitigates histopathological damage, alleviate oxidative stress and promotes immunomodulation in diabetic rats.

Objectives: S-methyl cysteine sulfoxide (SMCS) is a hydrophilic cysteine-containing natural compound found in plants and is known to possess antidiabetic and antioxidant properties. We investigated the antioxidant and immunomodulatory properties of SMCS, as well as histopathological changes in the liver and pancreas in streptozotocin (STZ)-induced diabetic rats.

Methods: The rats were divided into the following groups: control (CG), comprising non-diabetic rats; STZ-DB, comprising STZ-induced diabetic rats; and STZ-SMCS, comprising STZ-induced diabetic rats treated with SMCS. SMCS (200 mg/kg) was administered by gavage daily for 30 days. Biochemical and cytokine analyses, catalase (CAT) and superoxide dismutase (SOD) activities assays and histopathological analysis of liver and pancreas tissues were performed.

Results: SMCS treatment reduced glycemia (p<0.05), decreased triglyceride (p<0.01) and very-low-density lipoprotein (VLDL) levels (p<0.01), and increased SOD and CAT activity in the liver (both p<0.01) compared with STZ-DB group. Higher activity values of IL-10 were observed in the STZ-SMCS group than in the other groups (p<0.001). Liver glycogen was significantly improved in the STZ-SMCS group compared with the STZ-DB group. SMCS also ameliorated damage to pancreatic islets, which resulted in restoration of their morphology.

Conclusions: Oral treatment of SMCS showed improvement of the morphological alterations in liver and pancreatic islet in diabetic rats. These beneficial morphological effects of SMCS can be partially explained by IL-10 modulation associated with antioxidant action.