Protection of myocardium in streptozotocin-induced diabetic rats by water extracts of Hsian-tsao (Mesona procumbens Hemsl.).

The myocardial protective effects of water extracts from Hsian-tsao (Mesona procumbens Hemsl.) on diabetic rats were investigated. Thirty Sprague-Dawley male rats were randomly divided into three groups, "control group" (n=10) with intraperitoneal saline injection, "diabetic group" (n=10) with 60 mg of intraperitoneal streptozotocin injection per kg of body weight and "Hsian-tsao group" (n=10) with intragastric administration of Hsian-tsao extracts every day for 4 weeks after intraperitoneal streptozotocin injection. Body weight and blood sugar concentrations were measured before and after model induction in the three groups. Thrombospondin-1 (TSP-1) expressions in the myocardium were monitored by immunohistochemistry and rt-RT-qPCR analysis. Myocardial ultrastructural changes were also analyzed by us-ing transmission electron microscopy. Our results demonstrated that diabetic myocardial ultrastructural changes included myofibrillar disarrangements, mitochondria disruption, and an increase in nuclear membrane invaginations. These damages were significantly less severe in the Hsian-tsao group compared with the diabetic group. A significant increase of the TSP-1 expression was also observed in the hearts of the diabetic rats (p<0.01), but it was relatively lower in the Hsian-tsao group than in the diabetic group (p<0.01). It suggested that Hsian-tsao treatment in the diabetic rats effectively prevented the pathological alterations in the myocardium and decreased TSP-1 expression.