Korean J Med.  2000 Feb;58(2):180-188.

Anti-hyperglycemic, anti-hypertriglyceridemic and stimulatory effect on glucose transporter 4 mRNA appearance of hydrolysable tannins(Rosanin) of the rosa rugosa root in the streptozotocin-injected diabetic rats

• Jeon KY
• Mun SP

Abstract

BACKGROUND: The root of the plant Rosa rugosa has been reported to have an anti- hyperglycemic and anti-hyperlipidemic effect in experimental animals. But its definite anti-hyperglycemic and anti-hyperlipidemic substance has not yet been identified. In this study, we found the hydrolysable tannins of the hot water extract of the Rosa rugosa root had those effects, and named it as Rosanin. And its mode of actions were evaluated.
METHODS
Three groups of streptozotocin-injected rats and two groups of buffer-injected control rats were given 10 mg/Kg/ml of Rosanin, or glibenclamide, or water by nasogastric tubes for three weeks. Blood sugar, insulin, triglyceride and GLUT4 mRNA levels were checked in the fasting state. Liver, kidney and pancreatic specimens were observed by light microscopy.
RESULTS
All the water-treated, glibenclamide-treated and Rosanin-treated diabetic rats had significantly higher blood sugar levels compared to that of normal control rats (p< 0.001, p< 0.001 and p< 0.05, respectively); but Rosanin-treated diabetic rats had significantly lower blood sugar level compared to those of glibenclamide-treated and water-treated diabetic rats (p< 0.05 and p< 0.001, respectively). In the Northern blot analysis from the experimental rats' hind limb skeletal muscle RNA, all the diabetic rats showed variously decreased levels of GLUT4 mRNA compared to those of normal control rats. The water-treated diabetic group showed a 66% decline (p< 0.001); the glibenclamide-treated diabetic group led with a 2% decline; and the Rosanin-treated diabetic group revealed a 23% decline (p< 0.05). All three groups of diabetic rats had significantly lower insulin levels compared to that of normal control rats (p< 0.01), but glibenclamide-treated diabetic rats and Rosanin-treated diabetic rats had significantly higher insulin level compared to that of water-treated diabetic rats (p< 0.05, each). Furthermore, Rosanin treatment significantly decreased plasma blood triglyceride levels of streptozotocin-injected diabetic rats compared to water-treated and glibenclamide-treated, streptozotocin-injected diabetic rats (p< 0.05 and p< 0.01, respectively). The light microscopic observation of pancreatic specimens of the Rosanin-treated diabetic group showed more intact islet cells than the water-treated diabetic groups. Liver specimens of the Rosanin-treated diabetic group showed a normal appearance, but those of the water-treated diabetic groups showed severe spotty hepatic necrosis and many regenerating hepatic cells.
CONCLUSION
Rosanin has an anti-hyperglycemic effect. This effect is due, in part, through the enhancement of the GLUT4 mRNA expression, the stimulation of insulin secretion in hyperglycemia, and through the preservation of pancreatic beta cells from the destructory damages of the streptozotocin. Further, it has anti-hypertriglyceridemic and hepatotoxicity-relieving effects in streptozotocin-injected diabetic animals. Abbreviations : Rosanin, the high molecular weight hydrolysable tannins of the hot water extract of the Rosa rugosa root; has an average molecular weight of about 830,000; it mainly consists of D-glucose units linked by the 1-->4 gulcoside bonds and phenolic acids, such as ellagic and gallic acid1).

Keyword

Rosa rugosa; Hydrolysable tannin; Rosanin; Glucose transporter; Hypertriglyceridemia

MeSH Terms

Abbreviations
Animals
Blood Glucose
Blotting, Northern
Extremities
Fasting
Glucose Transport Proteins, Facilitative*
Glucose*
Glyburide
Hepatocytes
Hyperglycemia
Hypertriglyceridemia
Insulin
Insulin-Secreting Cells
Islets of Langerhans
Kidney
Liver
Microscopy
Molecular Weight
Muscle, Skeletal
Necrosis
Phenol
Plants
Plasma
Rats*
RNA
RNA, Messenger*
Rosa*
Streptozocin
Tannins
Triglycerides
Water
Blood Glucose
Glucose
Glucose Transport Proteins, Facilitative
Glyburide
Insulin
Phenol
RNA
RNA, Messenger
Streptozocin
Tannins
Water