Scutellaria baicalensis Enhances the Anti-Diabetic Activity of Metformin in Streptozotocin-Induced Diabetic Wistar Rats

Abstract

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.

Phytotherapy in diabetes: Review on potential mechanistic perspectives

“…The ethanolic extract of Scutellaria baicalensis, as well, proves its antioxidant role in a STZ-induced diabetic model, and enhances the antidiabetic effect of metformin [206] . In addition, in a study on the antioxidant and antiglycation properties of some traditional Chinese medicine used to treat DM, Aralia taibaiensis outperformed other extracts in most of the assays except for the inhibition of early glycation products formation which was mostly inhibited by Acanthopanax senticosus extract [207] .…”

Baicalin From Scutellaria baicalensis Impairs Th1 Polarization Through Inhibition of Dendritic Cell Maturation

“…Baicalin has been widely used for the treatment of various diseases such as hepatitis, pneumonia, allergies, diabetes, and cancer (11,12). Previous studies have demonstrated that baicalin possesses a wide range of biological and pharmacological activities, including anti-inflammatory, antioxidant, and anti-cancer properties (13 -17).…”

Long-term baicalin administration ameliorates metabolic disorders and hepatic steatosis in rats given a high-fat diet

“…Baicalin, a polyphenolic compound, is a major bioactive flavonoid isolated from the radix of Scutellaria baicalensis, which is widely used in traditional Chinese medicine (TCM) to treat inflammation, hypertension, cardiovascular diseases, and bacterial and viral infections [18] . Scutellaria baicalensis also shows promise in preventing dyslipidemia and ameliorating hyperglycemia in STZ-induced diabetic rats, both alone and in combination with other herbs [19] . Studies with an experimental model demonstrated that extracts of Scutellaria baicalensis significantly decreased the plasma total cholesterol and triglyceride levels of rats fed a high-fat diet [20] .…”