Antihyperglycemic and Antioxidant Effects of Salacia reticulata and Caralluma tuberculata in Alloxan-Induced Diabetic Female Rats

Objective: Diabetes mellitus (DM) is a major metabolic disorder associated with hyper-glycemia and oxidative stress. Traditional medicinal plants remain important sources of bioactive compounds with potential antidiabetic activity. Salacia reticulata and Caralluma tuberculata are two important medicinal plants that have been reported to have antidiabetic effects. The growing burden of type 2 diabetes and the need for therapies that address both hyperglycemia and oxidative stress underscore the necessity to investigate these two medicinal plants. Therefore, the current study evaluated the antihyperglycemic, antioxidant, and protective effects of Salacia reticulata and Caralluma tuberculata in an alloxan-induced diabetic female rat model. Methods: Ethanolic extracts of S. reticulata and C. tuberculata were characterized by total phenolic content (TPC), total flavonoid content (TFC), DPPH radical-scavenging assay, and UPLC–MS/MS metabolite profiling. Female Wistar rats (n = 42) were randomly assigned to seven groups (n = 6/group), including normal control, diabetic control, extract-treated non-diabetic groups, diabetic extract-treated groups, and a metformin-treated diabetic group. Diabetes was induced by alloxan (130 mg/kg), followed by oral treatment for 8 days with extracts or metformin (500 mg/kg/day). Fasting blood glucose, oral glucose tolerance, serum malondialdehyde (MDA), antioxidant markers (SOD1, GSH, and CAT), and liver and kidney histopathology were assessed. Results: Both plant extracts significantly reduced fasting blood glucose compared with baseline, with S. reticulata showing a greater reduction (22.8%) than C. tuberculata (12.3%), and a response comparable to metformin (27.4%). Diabetic rats exhibited increased MDA and reduced antioxidant enzyme activities. C. tuberculata significantly lowered MDA levels and increased SOD1 activity, suggesting moderate antioxidant effects, whereas S. reticulata showed higher phenolic and flavonoid contents and the highest DPPH scavenging activity. UPLC–MS/MS identified 33 compounds in S. reticulata and 24 in C. tuberculata. Histopathological findings supported improvement of diabetes-associated renal and hepatic damage. Conclusions: Within the eight-day experimental period, both extracts demonstrated significant acute antidiabetic and antioxidant effects with distinct redox–metabolic profiles. However, further long-term studies are recommended to evaluate their sustained efficacy, safety, and potential as complementary therapeutic agents for diabetes management.