p53 Rather Than ß-Catenin Mediated the Combined Hypoglycemic Effect of Cinnamomum cassia (L.) and Zingiber officinale Roscoe in the Streptozotocin-Induced Diabetic Model.

Background: The antioxidant, hypoglycemic, and insulin-enhancing effects of ginger and cinnamon were previously confirmed in experimental and human studies, while the combined effect of ginger and cinnamon was not thoroughly investigated until now. Objectives: This study was designed to assess the antidiabetic effect of combined administration of ginger (Zingiber officinale Roscoe) and cinnamon (Cinnamomum cassia L.) in streptozotocin (STZ)-induced diabetic rats compared to metformin and to explain the mechanism behind this effect. Materials and methods: STZ was utilized to induce diabetes mellitus in male Sprague-Dawley rats. Assessments of fasting blood glucose level (BGL), the total antioxidant capacity (TAC), serum insulin, HOMA-IR, and HOMA-ß cells were performed. Pancreatic gene expression of ß-catenin and p53 was assessed using RT-PCR. Assessment of histopathological alterations of pancreatic islet cells was performed using routine and immunohistochemical techniques. Results: BGL significantly decreased (p = 0.01), while serum insulin and TAC significantly increased (p < 0.001) in both metformin- and ginger plus cinnamon-treated groups compared to the untreated diabetic group. HOMA-ß cell index significantly increased (p = 0.001) in ginger plus cinnamon, indicating their enhancing effect on insulin secretion in diabetic conditions. p53 gene expression was significantly upregulated (p < 0.001), while ß-catenin was insignificantly downregulated (p = 0.32) in ginger plus cinnamon-treated groups. Insulin immunoexpression in ß cells significantly increased (p = 0.001, p = 0.004) in metformin- and ginger plus cinnamon-treated groups, respectively. Conclusions: The combined administration of ginger and cinnamon has a significant hypoglycemic and antioxidant effect in STZ-induced diabetes mostly through enhancing repair of islet cells mediated via upregulation of pancreatic p53 expression. Therefore, testing this effect in diabetic patients is recommended.

Zingiber officinale preserves testicular structure and the expression of androgen receptors and proliferating cell nuclear antigen in diabetic rats.

The aim of this study was to assess the efficacy of Zingiber officinale, commonly referred to as ginger, in preserving the structural integrity of testis in streptozotocin (STZ)-induced diabetic rats compared to the efficacy of metformin, the traditional effective antidiabetic drug. STZ was utilised for the induction of diabetes mellitus in male Sprague Dawley rats. The study included five groups (n = 6 each), namely the normal control, ginger-treated normal, nontreated diabetic, metformin-treated diabetic and ginger-treated diabetic groups. Biochemical assessment of fasting blood glucose level (BGL) and total antioxidant capacity (TAC) was performed. Histopathological assessment of the testes was performed using routine and immunohistochemical techniques. Fasting BGL significantly (p = .01) reduced, whereas TAC significantly increased (p < .001) in metformin- and ginger-treated diabetic rats compared to those in untreated diabetic rats. Metformin and ginger reduced the degenerative changes observed in the testes of diabetic rats, significantly reduced (p < .001) caspase-3 immunoexpression, and significantly increased (p < .001) the immune-expression of androgen receptors and proliferating cell nuclear antigen. Ginger has antidiabetic effects and preserves testicular structural integrity and, thus, is recommended as an adjuvant therapy for male diabetic patients in the reproductive period.