Scutellaria baicalensis enhances the anti-diabetic activity of metformin in streptozotocin-induced diabetic Wistar rats.
Oxidative stress is the root cause of diabetic macro- and microvascular complications. Biochemical and epidemiological studies indicate that current treatments for diabetes do not reduce risks of developing complications, suggesting their inability to alleviate the levels of oxidative stress. This study in streptozotocin (STZ)-induced diabetic rats was carried out to investigate the effect of combining the antidiabetic drug, metformin, with an ethanolic extract of Scutellaria baicalensis, a plant whose root is known for its radical scavenging activity. Three groups of STZ-induced diabetic rats were given the following treatments for 30 days: (1) metformin 500 mg/kg, (2) S. baicalensis 400 mg/kg, (3) metformin 500 mg/kg + S. baicalensis extract 400 mg/kg. In addition, vehicle-treated diabetic and nondiabetic controls were used in the experiment. The rats treated with S. baicalensis and metformin + S. baicalensis had elevated hepatic activities of the antioxidant enzymes--superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) compared to the vehicle- and metformin-treated diabetic groups (p < 0.05). Plasma and hepatic lipid peroxide concentrations in the herb-treated and herb + metformin-treated groups were also significantly reduced (p < 0.05). In addition, the combined treatment caused significant elevations of plasma and pancreatic insulin levels and reductions of plasma and hepatic triglycerides (TG) and cholesterol levels. The study thus showed that S. baicalensis enhanced the antidiabetic effect of metformin in STZ-induced diabetic rats by improving the antioxidant status. It also increased pancreatic insulin content as well as improved the lipid profile in these rats.
Food Science and Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 3, Singapore.
Viduranga Y
VY
Waisundara
Annie
A
Hsu
Dejian
D
Huang
Benny Kwong-Huat
BK
Tan
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D004365:Drugs, Chinese Herbal / Q000494:pharmacology* / Q000627:therapeutic use; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D007328:Insulin / Q000097:blood; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008687:Metformin / Q000494:pharmacology* / Q000627:therapeutic use; D018384:Oxidative Stress / Q000187:drug effects; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D031364:Scutellaria baicalensis; D013311:Streptozocin
D000975:Antioxidants; D001786:Blood Glucose; D004365:Drugs, Chinese Herbal; D007004:Hypoglycemic Agents; D007328:Insulin; D010936:Plant Extracts; C499814:Scutellaria baicalensis extract; D013311:Streptozocin; D008687:Metformin