Antihyperglycemic, antihyperlipidemic and antiglycation effects of Byrsonima crassifolia fruit and seed in normal and streptozotocin-induced diabetic rats.

The hypoglycemic effects of hexane, chloroform and methanol extracts from fruits and seeds of Byrsonima crassifolia were evaluated by oral administration to normoglycemic and streptozotocin-induced severe diabetic rats (SD). The anti-diabetic effect was examined by blood glucose, triglycerides, lipid peroxidation, total cholesterol levels in the serum, glycogen content of liver and skeletal muscles, superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and oxidized glutathione (GSSG) levels. The most active extracts were obtained with hexane. Hexane and chloroform extracts from fruits and seeds of Byrsonima crassifolia increased the levels of SOD, GSH, GSSG and CAT, hepatic glycogen content, glucose-6-phosphatase (G6Pase) and the plasma insulin levels. They also decreased glucokinase (GK) and TBAR (thiobarbituric acid assay). In conclusion, Byrsonima crassifolia possesses significant antihyperglycemic properties after 4 h of a single oral dose. It can also improve hyperlipidemia and hyperinsulinemia in streptozotocin-induced diabetic rats. Both extracts exhibited significant inhibitory activity against AGEs (advanced glycation end products) formation with IC(50) values ranging from 94.3 to 138.7 µg/ml. Therefore, B. crassifolia can be considered as a potential safe anti-diabetic agent.

Nephroprotective activity of Prosthechea michuacana against cisplatin-induced acute renal failure in rats.

In Mexican traditional medicine the orchid Prosthechea michuacana is highly valued as a food and in the treatment of various human diseases, including drug-related renal disease. Methanol, hexane, and chloroform extracts of bulbs of P. michuacana were studied in the cisplatin-induced renal injury model in rats. Results showed that treatment with cisplatin induced significant elevations in concentrations of blood urea and serum creatinine and in lipid peroxidation. Treatments with methanolic extract (200, 400 and 500 mg/kg) increased levels of biochemical markers of renal injury like reduced glutathione, glutathione S-transferase, and superoxide dismutase and inhibited the increases in blood urea and serum creatinine concentrations and lipid peroxidation induced by cisplatin. Hexane and chloroform extracts did not show any effect. The results obtained in the present study indicate that this orchid can be a potential source of natural nephroprotective activity.