Evaluation of traditional medicine: effects of Cajanus cajan L. and of Cassia fistula L. on carbohydrate metabolism in mice

The authors report the results of pharmacologic evaluation of two medicinal plants: Cajanus cajan (L.) Millsp and Cassia fistula, which are used in Panamanian folk medicine for the treatment of diabetes. It was found that the aqueous fraction of the leaves and stems of C. cajan did not produce any hypo blood sugar effect in normoglycemic mice; instead, it produced a hyperglycemia with doses of 500 mg/kg and 1000 mg/kg (p less than 0.001). Only with a dose of 300 mg/kg a short lived decrease in the glycemia was seen at one hour. On the contrary, the folk use of the leaves of C. fistula for diabetes seems to have some correlation with the popular frek use. The aqueous fraction produced a significant decrease in the glycemia (p less than 0.001) at 4 and 24 hours with doses of 300 and 500 mg/kg, and at one and four hours after the dose of 1000 mg/kg (p less than 0.001). In the glucose tolerance test, the aqueous fraction of C. cajan produced a significant and short lasting decrease (p less than 0.05) with the dose of 300 mg/kg, while the dose of 500 mg/kg did at 0.25, 0.5 and 1 hour (p less than 0.01). The 1000 mg/kg dose produced a significant increase in glucose tolerance at 1 and 2 hours (p less than 0.05). The aqueous fraction of C. fistula produced a significant decrease (p less than 0.05) with the dose of 500 mg/kg at 0.25 and 0.5 hours. The 1000 mg/kg dose produced a significant increase (p less than 0.001) at 0.25 and 2 hours.