Résumé
Mechanism of blood sugar lowering by the crude/impure swerchirin (SWI) isolated from the hexane fraction of Swertia chirayita was investigated. Single oral administration of SWI (50 mg/kg, body wt) to fed CF rats induced about 60% (max.) fall in blood glucose by 7 hr post-treatment. This was associated with marked depletion of aldehyde-fuchsin stained beta-granules and immunostained insulin in the pancreatic islets. In vitro, glucose uptake and glycogen synthesis by muscle (diaphragm) was significantly enhanced by the serum of SWI-treated rat. At 100, 10 and 1 microM final concentration, SWI greatly enhanced glucose (16.7 mM)-stimulated insulin release from isolated islets. It is therefore concluded that SWI lowers blood glucose level by stimulating insulin release from islets of Langerhans.
Sujets)
Animaux , Glycémie/métabolisme , Hexanes , Hypoglycémiants/isolement et purification , Ilots pancréatiques/effets des médicaments et des substances chimiques , Mâle , Plantes médicinales , Rats , Xanthènes/isolement et purification , XanthonesRésumé
Effect of Swerchirin (1:8 dihydroxy 3:5 dimethoxy xanthone) isolated from hexane fraction of Swertia chirayita on the blood sugar level of healthy and streptozotocin treated rats was studied. Streptozotocin was administered in citrate buffer (pH-4.5) intravenously / 35 and 65 mg/kg body wt to Charles Foster strain albino rats. Swerchirin (50 mg/kg, po) suspended in gum acacia was fed through cannula to the above rats and to a group of healthy rats. Blood sugar estimated at 0, 1, 3 and 7 hr after, indicated a very significant lowering in healthy and streptozotocin (35 mg/kg iv) but not in streptozotocin (65 mg/kg) treated rats.
Sujets)
Animaux , Glycémie/analyse , Diabète expérimental/sang , Hyperglycémie/sang , Hypoglycémiants/pharmacologie , Mâle , Rats , Streptozocine , Xanthènes/pharmacologie , XanthonesRésumé
Hexane fraction of S. chirayita (250 mg/kg body wt.) induced significant fall in blood sugar and significant increase in plasma IRI simultaneously after single oral administration without influencing liver glycogen concentration in albino rats. On the other hand, daily administration for 28 days resulted in significant lowering of blood sugar and increase in plasma IRI along with a significant rise in liver glycogen. Intestinal absorption of glucose was not inhibited by hexane fraction. It is suggested that hexane fraction of S. chirayita possibly acts through its insulin releasing effect.