Anti-diabetic agents from medicinal plants inhibitory activity of Schizonepeta tenuifolia spikes on the diabetogenesis by streptozotocin in mice

The Schizonepeta tenuifolia spikes (STS) have been used as a traditional folk medicine for antiinflammatory, analgesic, anti-pyretic and anti-spasmodic purpose in Korea. Phytosterols (mixture of campesterol 3.68%, stigmasterol 2.30% and beta-sitosterol 94.02%) and hesperidin were isolated by chromatography from ether and n-BuOH fractions of STS respectively. These compounds significantly reduced the blood glucose level and lessened the loss of body weight and water consumption dose-dependently when administered at a i.p. doses of 10 and 20 mg/kg for 4 days after the i.v. injection of streptozotocin (180 mg/kg). In the morphologic study, these compounds showed protective activity on the pancreatic islets, especially p-cells, from the degenerative changes by streptozotocin.