Oolong Tea Infusion Lowers Blood Glucose in Alloxan-Induced Diabetic Mice

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia and associated systemic and oral complications. Plant-based therapies are increasingly studied as complementary options for improving glycemic control, and oolong tea (Camellia sinensis), which contains antioxidant polyphenols, has been proposed to possess antidiabetic activity. This study evaluated the glucose-lowering effect of oolong tea infusions at concentrations of 10%, 20%, and 40% in alloxan-induced diabetic mice. Male mice were divided into five groups, including negative and positive controls and three treatment groups receiving the respective infusions. Diabetes was induced with alloxan (16.8 mg/kg), and baseline blood glucose was measured on day three. On day five, mice received oral administration of oolong tea infusion (0.25 mL/25 g), followed by blood glucose measurement one hour later. Alloxan successfully induced hyperglycemia, and the 10% and 20% oolong tea infusions significantly reduced blood glucose levels to values comparable to healthy controls. The 40% infusion produced a smaller reduction, suggesting diminished bioactivity at higher concentration, likely due to polyphenol degradation and higher caffeine content. These findings indicate that oolong tea infusion has meaningful antidiabetic potential in this experimental model, with moderate-strength preparations showing the strongest effect. Oolong tea may offer a complementary approach for supporting glycemic control, although further studies are needed to clarify optimal dosing and underlying mechanisms.