Extrapancreatic insulin effect of glibenclamide

Glibenclamide protects against thioacetamide-induced hepatic damage in Wistar rat: investigation on NLRP3, MMP-2, and stellate cell activation

Glibenclamide (GLB), most widely used in the treatment of type II diabetes mellitus, inhibits K⁺_ATP channel in pancreatic-β cells and releases insulin, while thioacetamide (TAA) is a well-known hepatotoxicant and most recommended for the induction of acute and chronic liver disease. The purpose of this study was to evaluate the hepatoprotective potential of GLB against TAA-induced hepatic damage in Wistar rats. TAA (200 mg/kg, ip, twice weekly) and GLB (1.25, 2.5, and 5 mg/kg/day, po) were administered for 6 consecutive weeks. Different biochemical, DNA damage, histopathological, TEM, immunohistochemical, and western blotting parameters were evaluated. GLB treatment has no effects on the TAA-induced significant decrease in body and liver weights. TAA treatment significantly increased liver index and treatment with GLB has no effect the same. TAA treatment altered the liver morphology, whereas treatment with GLB normalized the alteration in morphology. Further, significant increase in oxidative stress, apoptosis, and DNA damage was found in TAA-treated animals and GLB treatment significantly reduced these effects. TAA-induced plasma transaminases and serum ALP levels were significantly restored by GLB. Furthermore, histopathological findings showed the presence of lymphocyte infiltration, collagen deposition, bridging fibrosis, degeneration of portal triad, and necrosis in TAA-treated animals and GLB intervention significantly reduced the same. TEM images revealed that GLB significantly normalized the hepatic stellate cell morphology as well as restored the number of lipid droplets. GLB treatment significantly downregulated the expressions of TGF-β1, α-SMA, NLRP3, ASC, caspase-1, and IL-1β, and upregulated MMP-2 and catalase against TAA-induced liver damage. The outcomes of the present study confirmed that GLB ameliorated the liver damage induced by TAA.

Sustained-release versus immediate-release glipizide for treatment of type 2 diabetes mellitus in chinese patients: A randomized, double-blind, double-dummy, parallel-group, 12-week clinical study

BACKGROUND

Few data exist that have compared sulfonylurea formulations in differing ethnic populations. Most studies of sulfonylureas have been performed in white patients with type 2 diabetes mellitus.

OBJECTIVE

The aim of this study was to compare the efficacy and tolerability of a sustained-release glipizide (GSR) formulation with those of immediate-release glipizide (GIR) in Chinese patients with type 2 diabetes mellitus.

METHODS

This randomized, double-blind, double-dummy, placebo-controlled, parallel-group, clinical study enrolled adult patients with type 2 diabetes mellitus who were already being treated with diet and a sulfonylurea. Patients were randomized to receive either GSR 10 mg PO QD or GIR 5 mg PO BID for 12 weeks. Because these 2 formulations differed in appearance, each patient also received placebo resembling the alternate formulation, to be received at the alternate frequency. Drugs dispensed but not used were returned to the investigators and counted to monitor compliance with the protocol. For efficacy assessment, fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA(1c)) were measured before and after treatment. Tolerability was measured by adverse events (AEs), which were evaluated by the attending physician during each clinical visit.

RESULTS

Of the 57 patients (37 men, 20 women) enrolled in the study, 41 completed it. All were Han Chinese of Taiwanese origin, and had the following characteristics: age range, 33 to 69 years; mean (SE) height, 161.99 (9.42) cm; and mean (SE) body mass index, 25.21 (3.43) kg/m2. An intent-to-treat analysis found that the mean (SE) changes from baseline in FPG (-30.00 [10.67] vs -25.96 [11.15] mg/dL) and in HbA(1c) (-0.08% [0.24%] vs +0.14% [0.22%]) during the 12-week period of the study were not significantly different between the 2 formulations. For patients in the per-protocol analysis, mean (SE) changes from baseline in FPG (-30.00 [10.67] vs -16.52 [7.79] mg/dL) and HbA(1c) (-0.08% [0.24%] vs +0.11% [0.25%]) were also not significantly different. The most frequently reported AEs were urinary abnormality (22.2%) and tachycardia (6.7%) for the GSR group and GIR group, respectively. No serious drug-related AEs were observed in either group.

CONCLUSION

In this small study, treatment with oral GSR (10 mg QD) was not significantly different from that of treatment with GIR (5 mg BID) with respect to short-term (12 weeks) FPG and HbA(1c) reductions in these ethnic Chinese adults with type 2 diabetes mellitus receiving treatment with a sulfonylurea.

Effect of the sulfonylurea glyburide on glycogen synthesis in alloxan-induced diabetic rat hepatocytes

1. The effect of glyburide (glibenclamide) treatment on the liver glycogen levels of diabetic rats have been studied. 2. 3 weeks treatment with glyburide (5 mg/kg, orally) increased liver glycogen and decreased blood glucose levels. 3. The results of this study demonstrated that the sulfonylurea, glyburide is capable of exerting direct insulin-like effects on liver glycogen values in vivo.

Effect of the sulfonylurea glyburide on glycogen synthase activity in alloxan-induced diabetic rat adipocytes

1. The effect of glyburide (glibenclamide) treatment in vivo on the adipose tissue glycogen synthase activity of type II diabetic rats has been studied. 2. Three week treatment of diabetic animals with glyburide (5 mg/kg orally, in saline) increased adipose glycogen synthase activity and decreased blood glucose levels. 3. These results demonstrate that the sulfonylurea glyburide is capable of exerting direct insulin-like effect on adipose glycogen-synthase activity of type II diabetic rats in vivo.

Long-term effects of glipizide on insulin secretion and blood glucose control in patients with non-insulin-dependent diabetes mellitus

Of 23 patients with non-insulin-dependent diabetes mellitus (NIDDM), whose fasting blood glucose had not reached less than or equal to 6.0 mmol.l-1 after 10 weeks of dietary regulation, 15, who had had a weight reduction of -2.8 kg by dietary control, did achieve a fasting blood glucose less than or equal to 6.0 mmol.l-1 after addition of less than or equal to 20 mg glipizide daily. They had a sustained (greater than or equal to 2 years) increase in meal-induced insulin secretion (32% increase in postprandial C-peptide AUC), and a sustained reduction in postprandial hyperglycaemia (34% reduction in AUC). Ten of the patients took a mean daily dose less than 5 mg (4.8 mg) and had a sustained increase in insulin secretion rate (increased C-peptide slope). The 15 patients had no elevation of basal insulin secretion and no impairment of weight reduction. The remaining 8 subjects, who showed little or no weight reduction on dietary control, had little or no reduction in fasting blood glucose despite long-term treatment with 20 mg glipizide daily, a less sustained increase in meal-induced insulin secretion, a smaller reduction of postprandial hyperglycaemia, and an increase in body weight. On diagnosis the 8 subjects did not differ from the other 15 subjects in age, body weight, blood glucose, HbA1c, C-peptide or insulin, nor in their glucose and insulin responses to a test dose of glipizide; the main reason for the apparent drug failure appeared to be deficient compliance with dietary regulation rather than a primary inability to respond to sulphonylurea treatment.(ABSTRACT TRUNCATED AT 250 WORDS)