Antidiabetic effects of Swertia macrosperma extracts in diabetic rats.
BACKGROUND
Swertia macrosperma is a traditional folk medicine used for its anti-hepatitis, antipyretic and antidotal effects as "Dida" or "Zangyinchen" in Tibet, Yunnan and Guizhou province for a long time, and it has been reported for its anti-diabetic effects in a Chinese patent. Swertia macrosperma was reported rich in xanthones, iridoids, seco-iridoids and their glycosides, several of which had been documented as potential antidiabetic agents. The objective of this study was to investigate the antidiabetic effect of Swertia macrosperma in diabetic rats.


METHODS
This study was designed firstly to evaluate the effect of Swertia macrosperma on glucose consumption in HepG2 cells. Based on the result in HepG2 cells, the antidiabetic effect of ethanol extract (EE) and n-butanol extract (BE) were investigated in diabetic rats induced by high fat fed and streptozotocin. The effects of EE and BE on fasting blood glucose, oral glucose tolerance test, serum insulin, glycosylated hemoglobin, serum lipid level, serum antioxidant parameters, glucokinase, glucose-6-phosphatase activities and glycogen content in liver tissue were measured, histology examination of pancreatic tissue was also carried out.


RESULTS
After 4 weeks treatment with EE and BE, apparently decreased fasting blood glucose concentrations were observed in these treated groups, compared with the diabetic control groups. Additionally, improvement in serum antioxidant parameters and lipid profile were evidenced clearly. Moreover, EE and BE had effects of protecting the pancreatic β-cells and stimulating insulin secretion from the remaining pancreatic β-cells, evidenced by pancreatic histology examination. Increased glucokinase activity and decreased glucose-6-phosphatase activity were observed in liver.


CONCLUSIONS
The results of in vivo and in vitro experiment suggested that EE and BE of Swertia macrosperma had excellent effects on controlling the hyperglycemia and hyperlipidemia in diabetic rats.
Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji School of Pharmaceutical Sciences, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
Yong-Long
YL
Wang
Zuo-Qi
ZQ
Xiao
Shan
S
Liu
Luo-Sheng
LS
Wan
Yao-Dong
YD
Yue
Yu-Tang
YT
Zhang
Zhao-Xia
ZX
Liu
Jia-Chun
JC
Chen
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use*; D002374:Catalase / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D005941:Glucokinase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000097:blood; D006442:Glycated Hemoglobin / Q000032:analysis; D006003:Glycogen / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D010179:Pancreas / Q000187:drug effects / Q000473:pathology; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000097:blood; D029967:Swertia
D000975:Antioxidants; D002374:Catalase; D005941:Glucokinase; D005947:Glucose; D005952:Glucose-6-Phosphatase; D005979:Glutathione Peroxidase; D006442:Glycated Hemoglobin; D006003:Glycogen; D007004:Hypoglycemic Agents; D007328:Insulin; D008055:Lipids; D008315:Malondialdehyde; D010936:Plant Extracts; D013482:Superoxide Dismutase
Anti-diabetes; Diabetic rat; Extracts; HepG2 cell; Swertia macrosperma