This study aimed to evaluate the biochemical, physiological, and anti-diabetic effects of Syzygium cumini (seeds) and Ziziphus vulgaris (seeds) extracts in streptozotocin (STZ)-induced diabetic rats. A total of 30 STZ-induced diabetic rats were randomized into five groups: Group 1 (Control), Group 2 (Negative Control: STZ + Vehicle), Group 3 (Standard Treatment Control: STZ + Glibenclamide 5 mg/kg), Group 4 (Low Dose PHPE: 200 mg/kg), and Group 5 (High Dose PHPE: 400 mg/kg). Blood samples were collected weekly to assess fasting blood glucose, and various biochemical parameters were analyzed, including serum glucose, ALT, AST, total protein, cholesterol, creatinine, and urea levels. Treatment with Syzygium cumini and Ziziphus vulgaris extracts significantly lowered fasting blood glucose levels in diabetic rats compared to the negative control. Biochemical analyses revealed improved liver function indicators, including reduced ALT and AST levels, particularly in groups treated with the high dose of polyherbal extract (PHPE). Kidney function markers showed varying levels across groups, with significant improvements in creatinine and urea levels observed in the treatment groups. The findings of this study suggest that Syzygium cumini and Ziziphus vulgaris extracts possess anti-diabetic properties and may ameliorate biochemical and physiological disturbances in STZ induced diabetic rats. These results support the potential therapeutic application of these plant extracts in managing diabetes and its complications, warranting further investigation into their mechanisms of action and long-term effects.