Biochemical evaluation of the hypoglycemic effects of extract and fraction of Cassia fistula linn. in alloxan-induced diabetic rats

Abstract

Various extracts of flowers of Cassia fistula Linn (Leguminosae) such as petroleum ether (60-80°), chloroform, acetone, ethanol, aqueous, and crude aqueous extracts and two fractions of ethanol extract were tested for antihyperglycemic activity in glucose-overloaded hyperglycemic rats. The effective antihyperglycemic extracts and fraction were tested for their hypoglycemic activity at two dose levels, 200 and 400 mg/kg, respectively. To confirm their utility in higher models, the effective extracts and fraction of C. fistula were subjected to antidiabetic study in an alloxan-induced diabetic model at two dose levels, 200 and 400 mg/kg, respectively. Biochemical parameters like glucose, urea, creatinine, serum cholesterol, serum triglyceride, high-density lipoprotein, low-density lipoprotein, hemoglobin, and glycosylated hemoglobin were also assessed in experimental animals. The petroleum ether and ethanol extracts of C. fistula and the water-soluble fraction of ethanol extract were found to exhibit significant antihyperglycemic activity. The extracts, at the given doses, did not produce hypoglycemia in fasted normal rats, and the fraction exhibited weak hypoglycemic effect after 2 h of the treatment. Treatment of diabetic rats with ethanol extract and water-soluble fraction of this plant restored the elevated biochemical parameters significantly (P<0.05) to the normal level. No activity was found in the petroleum ether extract of the plant. Comparatively, the water-soluble fraction of ethanol extract was found to be more effective than the ethanol extract, and the activity was comparable with that of the standard, glibenclamide (5 mg/kg).

Evaluation of Antidiabetic Activity of Hydroalcoholic Extract of Cassia fistula Linn. pod in Streptozotocin-Induced Diabetic Rats

“…34,35,47,53 Administration of glibenclamide or C. fistula pod extract at different doses for 60 days in STZ-induced diabetic rats showed significant reduction in the fasting blood glucose levels. These results are parallel with previous reports which have also showed a significant decline in blood glucose levels of diabetic rats after treatment with extract of C. fistula fruit pulp, 42 leaves, 38,54 bark, 34,35 flowers, 40,41 and root. 33 The reduction of fasting blood glucose level by C. fistula pod extract may be due to its many potential bioactive phytochemicals especially rhein glycosides, fistulic acid, sennosides A & B, anthoquinones, flavon-3-ol derivatives, kaempferol, proanthocyanidins like catechin, epiafzelechin, epicatechin and procyanidin 25 and quercetin dehydrates.…”

“…63 These results are consistent with earlier finding which have also reported significant improvement in oral glucose tolerance in C. fistula extract treated diabetic rats. 41,64 Glycosylated hemoglobin is considered as the most reliable marker of glycemic control in the body. 65 Glycation is a post translational non-enzymatic addition of sugar residues to N-terminal end of the hemoglobin beta chain.…”

“…19 Oxyanthraquinones, chrysophanol and chrysophanein, were also isolated from the seeds of C. fistula by Kuo et al, (2002). 32 Antihyperglycemic activity of C. fistula roots, 33 bark, 34-37 leaves 38,39 and flowers, 40,41 has been reported in diabetic animals by various workers. But reports on antidiabetic activity of C. fistula pods are very scanty.…”

“…These results are corroborated by earlier reports which have also reported decline of glycosylated hemoglobin levels thereby increasing the levels of total hemoglobin in diabetic rats treated with extract of C. fistula leaves, 38,39 bark 34,46,66 and flower. 40,41 Liver plays a crucial role in maintaining the blood glucose homeostasis. Insulin regulates glucose metabolism in the liver by stimulating glycolysis, glycogenesis and inhibiting gluconeogenesis.…”

To Evaluate the Antidiabetic and Rejuvenating Capability of Tissues on Alloxan Induced Diabetic Rats under the Effect of Ethanolic Leaf Extract of Coriandrum sativum: A Histopathological Study

“…Earlier reported by. 27 alkaloid exhibited to glycemic control. According to Jung et al 28 suggested that alkaloid from syzygium malaccense and penares schulzei inhibited glycogen phosphorylase as well as inhibited α-glucosidase both in vivo and in vitro.…”