Antioxidant and antihyperlipidaemic activity of protocatechuic acid on streptozotocin-diabetic rats

Oxidative stress in diabetes co-exists with a reduction in the antioxidant status, which can further increase the deleterious effects of free radicals. Hyperlipidaemia is one of the major risk factors of cardiovascular complications in diabetes. A study was undertaken to evaluate the antioxidant and antihyperlipidaemic activity of protocatechuic acid (PCA) on streptozotocin (STZ)-induced diabetic rats. The levels of thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were increased and the level of enzymatic and non-enzymatic antioxidants decreased except vitamin E. Lipid profile increased in diabetic rats, whereas HDL-C level decreased. These alterations reverted to near control levels after the diabetic rats were treated with PCA. Histopathological studies also revealed the protective effects of PCA on liver and kidney. These findings suggest that PCA treatment exerts a therapeutic property by decreasing the oxidative stress and lipid profile. The effect of PCA was comparable to glibenclamide, a well-known hypoglycaemic drug.

Protective effect of sesamol against myocardial infarction caused by isoproterenol in Wistar rats

This study was designed to investigate the cardioprotective effect of sesamol on isoproterenol (ISO)-induced myocardial infarction in adult male albino Wistar rats. The heart damage induced by ISO was indicated by elevated levels of the marker enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase-MB (CK-MB) and the levels of troponin T and I in the plasma. In addition, lipid peroxidative markers such as thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and lipid hydroperoxides (LHP) significantly increased in the plasma and heart. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) significantly decreased in the heart and (non-enzymic antioxidants) vitamin C, vitamin E and reduced glutathione (GSH)) levels significantly decreased in the plasma and heart in ISO-rats. Histopathological observations correlated with the biochemical parameters. Administration of sesamol at different doses 50, 100 and 200 mg/kg body weight intraperitoneally for 7 days prevented the above changes and improved towards normality; the 50 mg dose was more effective than the other two doses.

Antihypertensive efficacy of Melothria maderaspatana leaf extract on sham-operated and uninephrectomized DOCA-salt hypertensive rats

The plant Melothria maderaspatana (MME) has been used traditionally as antihypertensive and has been proven scientifically to possess high antioxidant and hepatoprotective activity. The present study has been designed to investigate the antihypertensive effect of ethanolic extract of MME leaves on sham-operated and uninephrectomized DOCA-salt-induced hypertensive male albino Wistar rats. A midscapular incision was made on each rat and the left kidney was excised after ligation of the renal artery. The surgical wound was closed using a suture. After one week recovery period, hypertension was induced by subcutaneous injection of DOCA-salt solution, twice a week, and the rats received a 1% sodium chloride solution as drinking water throughout the experimental period. After 6 weeks injection of DOCA-salt, systolic, diastolic and mean arterial blood pressure was significantly elevated as compared with sham-operated control. Treatment with MME significantly decreased theblood pressure. Thus, the results show that MME possesses antihypertensive activity in DOCA-salt hypertensive rats.

Antihyperlipidemic activity of 3-hydroxymethyl xylitol, a novel antidiabetic compound isolated from Casearia esculenta (Roxb.) root, in streptozotocin-diabetic rats

Casearia esculenta root (Roxb.) is widely used in traditional system of medicine to treat diabetes in India. An active compound, 3-hydroxymethyl xylitol (3-HMX), has been isolated, and its optimum dose has been determined in a short duration study and patented. In addition, the long-term effect of 3-HMX in type 2 diabetic rats on carbohydrate metabolism was investigated, and its antihyperglycemic effect was shown previously (Chandramohan et al., Eur J Pharmacol 2008;590:437-443). In this study we investigated the effect of 3-HMX on plasma and tissue lipid profiles in streptozotocin-induced diabetic rats. Diabetes was induced in adult male albino rats of the Wistar strain, weighing 180-200 g, by administration of streptozotocin (40 mg/kg of body weight) intraperitoneally. The normal and diabetic rats were treated with 3-HMX (40 mg/kg BW/day) for 45 days. The levels of total cholesterol, triglycerides, free fatty acids, and phospholipids were assayed in the plasma besides lipoprotein-cholesterol (high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and very low density lipoprotein-cholesterol (VLDL-C)) and tissues (liver, kidney, heart, and brain). Total cholesterol, triglyceride, free fatty acid, and phospholipid (LDL-C and VLDL-C in plasma only) levels increased in plasma and tissues significantly, whereas plasma HDL-C significantly decreased in diabetic rats. Treatment with 3-HMX or glibenclamide reversed the above-mentioned changes and improved toward normalcy. Histological study of liver also confirmed the biochemical findings. Thus administration of 3-HMX is able to reduce hyperglycemia and hyperlipidemia related to the risk of diabetes mellitus.

Effect of chrysin on hepatoprotective and antioxidant status in D-galactosamine-induced hepatitis in rats

Chrysin is a natural, biologically active compound present in many plants and possesses potent anti-inflammatory, anticancer and antioxidation properties. This work was designed to investigate the effect of chrysin, on the hepatoprotective efficacy in d-galactosamine-intoxication rats. d-galactosamine-induced toxicity was manifested by the elevation of serum hepatic marker enzyme activities (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma-glutamyl transpeptidase) and the lipid peroxidation process and by decreasing the antioxidant capacity of the plasma, erythrocyte and tissues. Treatment with chrysin (25, 50 and 100mg/kg body weight) decreased hepatic marker enzyme activities and lipid peroxidation products such as thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes, increased the activities of free-radical scavenging enzymes superoxide dismutase, catalase and glutathione peroxidase and the levels of non-enzymatic antioxidants reduced glutathione, vitamin C and vitamin E. These findings demonstrate that chrysin acts as a hepatoprotective and antioxidant agent against d-galactosamine-induced hepatotoxicity.

Antihyperglycemic effect of protocatechuic acid on streptozotocin-diabetic rats

Protocatechuic acid (PCA) (3,4-dihydroxybenzoic acid), a natural phenolic compound found in many edible and medicinal plants, is a major benzoic acid derivative with a strong antioxidative effect, 10-fold higher than that of alpha-tocopherol. The present study is aimed at evaluating the antidiabetic effect of PCA on STZ-diabetic rats. Diabetes was induced in male albino Wistar rats by the administration of STZ (40 mg/kg BW, i.p.). PCA was administered orally at three different doses (50, 100, 200 mg/kg BW/day) to STZ-diabetic rats for 45 days. Diabetic rats showed increase in plasma glucose and glycosylated hemoglobin (HbA1c) and a decrease in plasma insulin and hemoglobin (Hb). The activities of gluconeogenic enzymes like glucose 6-phosphatase and fructose 1,6-bisphosphatase increased whereas the glycolytic enzyme glucokinase decreased in the liver along with glycogen content. The oral administration of PCA or glibenclamide in saline, for 45 days, prevented the changes and improved toward normalcy. No significant effect was observed in normal rats treated with PCA. Thus, our results show that PCA at 100 mg possesses a potential antihyperglycemic effect that is comparable with glibenclamide.

Hypolipidemic activity of 18beta-glycyrrhetinic acid on streptozotocin-induced diabetic rats

Diabetes mellitus is a significant risk factor for cardiovascular complications. This study was undertaken to investigate the effect of 18beta-glycyrrhetinic acid on plasma glucose and plasma and tissue lipid profiles in streptozotocin-induced diabetic rats. Diabetes was induced in adult male albino rats of the Wistar strain, weighing 180-200 g, by administration of streptozotocin (40 mg/kg of body weight) intraperitoneally. Rats were randomly divided into seven groups. Group I: control animals (normal, nondiabetic animals), Group II: 18beta-glycyrrhetinic acid control, Group III: streptozotocin-diabetic, untreated animals; Groups IV, V and VI: streptozotocin-diabetic animals given 50, 100 and 200 mg 18beta-glycyrrhetinic acid, and Group VII: streptozotocin-diabetic animals given glibenclamide. The levels of total cholesterol, triglycerides, free fatty acids, and phospholipids, were assayed in the plasma besides lipoprotein-cholesterol (high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C) and very low density lipoprotein-cholesterol (VLDL-C)) and tissues (liver, kidney and heart). Total cholesterol, triglyceride, free fatty acid, and phospholipid (LDL-C and VLDL-C in plasma only) levels increased in plasma and tissues significantly, while plasma HDL-cholesterol significantly decreased in diabetic rats. Treatment with 18beta-glycyrrhetinic acid prevented the above changes and improved towards normalcy. Thus administration of 18beta-glycyrrhetinic acid is able to reduce hyperglycemia and hyperlipidemia related to the risk of diabetes mellitus.

Antihyperlipidemic effect of carvacrol on D-galactosamine-induced hepatotoxic rats

Carvacrol (2-methyl-5-(1-methylethyl)-phenol) is a predominant monoterpenic phenol occuring in many essential oils of the family Labiatae including, Origanum, Satureja, Thymbra, Thymus, and Corydothymus species. The present study was designed to investigate the effect of carvacrol on D-galactosamine (D-GalN)-induced hepatotoxicity in rats. D-GalN-hepatotoxic rats exhibited elevation in the serum bilirubin level and the activities of the hepatic marker enzymes aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma glutamyl transpeptidase. In the plasma, increased levels of very low density lipoprotein cholesterol and low density lipoprotein cholesterol and decreased high density lipoprotein cholesterol were observed. Further, an increase in the levels of total cholesterol, phospholipids, triglycerides, and free fatty acids in the plasma and tissues of liver and kidney were observed in hepatotoxic rats. The administration of carvacrol for 21 days prevented and improved these parameters toward normalcy. The results suggest that carvacrol affords a significant hepatoprotective and hypolipidemic effect against D-GalN-induced-rats.

Anthropometric parameters, lipid peroxidation and antioxidants in auto-rickshaw drivers

Anthropometric and several biochemical parameters were estimated in smoking and alcoholic-smoking auto-drivers and compared with normal auto-rickshaw drivers and normal subjects. Auto-drivers had a lower height, weight, and body mass index (BMI) compared with age-matched normal subjects. Plasma thiobarbituric acid reactive substances (TBARS), total cholesterol, TC/HDL-C ratio, and lactic acid increased significantly and ascorbic acid, alpha-tocopherol, reduced glutathione (GSH), hemoglobin, and HDL-cholesterol decreased significantly in auto-drivers when compared with normal subjects. Total cholesterol and TC/HDL-C ratio increased significantly in smoking auto-drivers; TBARS increased and ascorbic acid, alpha-tocopherol, GSH, and hemoglobin decreased significantly in alcoholic-smoking auto-drivers. Exposure of automobile pollutants associated with habits (cigarette smoking, alcohol) causes profound alterations in the levels of lipid peroxidation, antioxidants, hemoglobin, total cholesterol, HDL-cholesterol, TC/HDL-C ratio and lactic acid.

Influence of Piper betle on hepatic marker enzymes and tissue antioxidant status in D-galactosamine-induced hepatotoxic rats

D-galactosamine is a well-established hepatotoxicant that induces a diffuse type of liver injury closely resembling human viral hepatitis. D-galactosamine by its property of generating free radicals causes severe damage to the membrane and affects almost all organs of the human body. The leaves of Piper betle L., a commonly used masticatory in Asian countries, possess several biological properties. Our aim is to investigate the in vivo antioxidant potential of P. betle leaf-extract against oxidative stress induced by D-galactosamine intoxication in male albino Wistar rats. Toxicity was induced by an intraperitoneal injection of D-galactosamine, 400 mg/kg body weight (BW) for 21 days. Rats were treated with P. betle extract (200 mg/kg BW) via intragastric intubations. We assessed the activities of liver marker enzymes (aspartate amino-transferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyl transpeptidase) and levels of thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, superoxide dismutase, catalase, glutathione peroxidase, vitamin C, vitamin E, and reduced glutathione. The extract significantly improved the status of antioxidants and decreased TBARS, hydroperoxides, and liver marker enzymes when compared with the D-galactosamine treated group, demonstrating its hepatoprotective and antioxidant properties.

Effect of Umbelliferone on Tail Tendon Collagen and Haemostatic Function in Streptozotocin-Diabetic Rats

Diabetes mellitus is known to affect collagen in various tissues. Umbelliferone (7-hydroxycoumarin), a natural antioxidant and benzopyrone, is found in golden apple (Aegle marmelos Correa) and bitter orange (Citrus aurantium). Plant-derived phenolic coumarins have been shown to act as dietary antioxidants. In this study, we have investigated the influence of umbelliferone on collagen content and its effects on the tail tendon in streptozotocin-diabetic rats. Male albino Wistar rats (180-200 g) were made diabetic by intraperitoneal administration of streptozotocin (40 mg/kg). Normal and diabetic rats were treated with umbelliferone for 45 days. Diabetic rats had increased glucose and decreased insulin levels. Tail tendons of diabetic rats had increased total collagen, glycation and fluorescence, and decreased levels of neutral, acid and pepsin-soluble collagens. We have studied the effect of umbelliferone on haemostatic function because umbelliferone is also a coumarin derivative like the anticoagulant, warfarin. Diabetic rats had a significant decrease in prothrombin, clotting and bleeding time, and treatment with umbelliferone made these parameters almost normal. Our results show that umbelliferone controls glycaemia and has a beneficial effect on collagen content and its properties, i.e. collagen related parameters, in the tail tendon, which indicates recovery from the risk (recovery of animals from the risk of complications) of collagen-mediated diabetic polyneuropathy and diabetic nephropathy.

Cardioprotective effect of oleanolic acid on isoproterenol-induced myocardial ischemia in rats

This study was designed to investigate the protective effect of oleanolic acid (OA) against isoproterenol-induced myocardial ischemia in rat myocardium. Wistar strain rats were pretreated with OA (20, 40, and 60 mg/kg, s.c) for 7 days and then intoxicated with isoproterenol (ISO, 85 mg/kg, sc for 2 consecutive days). Heart were excised from the experimental animals and assessed for the activities of marker enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine phosphokinase (CPK)], the levels of lipid peroxide products [thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (HP) and conjugated dienes (CD)], myeloperoxidase (MPO), lipid profiles [total cholesterol (TC), free cholesterol, ester cholesterol, triglycerides (TG), free fatty acids (FFA) and phospholipids (PL)], and membrane-bound ATPase enzymes (total ATPase, Na(+)K(+) ATPase, Ca(2 +) ATPase, and Mg(2 +) ATPase). Troponin T and I were estimated in plasma. Leakage of cardiac markers, elevated lipid peroxidation with increased lipid profiles and decreased activities of membrane-bound ATPase enzymes were confirmed the severe myocardial damage occurring as a consequence of isoproterenol-induced ischemia, and they also showed the significant improvement effected by oleanolic acid pretreatment. These findings provided evidence that oleanolic acid was found to be protecting rat myocardium against ischemic insult and the protective effect could attribute to its anti-oxidative, anti-hyperlipedemic, and anti-arrhythmic properties as well as its membrane-stabilizing action.

Isomers (oleanolic and ursolic acids) differ in their protective effect against isoproterenol-induced myocardial ischemia in rats

The efficiency and safety of oleanolic acid (OA) and its isomer, ursolic acid (UA) in myocardial ischemia are poorly documented. This study appraised the efficacy of OA and UA in protecting the heart against oxidative damage induced by isoproterenol, since oxidative injury has been investigated as a potential initiator of myocardial necrosis. The level of TBARS increased whereas the antioxidants decreased significantly in the myocardium of ischemic animals. The levels were brought back to near normalcy in OA and UA pre-treated rats by scavenging the free radicals and blocking the induction of lipid peroxidation. These findings provide evidence that OA and UA protect rat myocardium against ischemic insult and the protective effect could be attributed to its antioxidant property and/or to a strengthening of myocardial membrane by its membrane stabilizing action. Among the two isomeric compounds, UA showed higher activity than OA.

Effect of Melothria maderaspatana leaf-tea consumption on blood pressure, lipid profile, anthropometry, fibrinogen, bilirubin, and albumin levels in patients with hypertension

OBJECTIVE

To determine the effect of Melothria maderaspatana (Linn.) leaf-tea on blood pressure, plasma lipid profile, fibrinogen, albumin together with serum bilirubin and anthropometric measurements in volunteer participants with hypertension, because all these variables have been shown to influence vascular events.

SUBJECTS AND DESIGN

A total of 50 subjects-25 (mean age of 58 +/- 9.0 years; 12 were women) with mild-to-moderate hypertension (systolic blood pressure [SBP] >or= 140 mm Hg; diastolic blood pressure [DBP] >or= 90 mm Hg) and 25 normotensives (mean age of 48 +/- 8.0 years; 11 women)-were selected for this study. Plasma lipid profile, fibrinogen, albumin, serum bilirubin, and anthropometric measurements were measured at baseline and after leaf-tea consumption by the patient with hypertension for 45 days.

RESULTS

SBP and DBP gradually decreased and pulse rate decreased. The total cholesterol, low-density lipoprotein cholesterol and triglycerides, and phospholipids levels decreased significantly and high-density lipoprotein cholesterol and serum bilirubin levels increased after tea consumption in patients with hypertension. We also observed significant body weight loss and reduction in fibrinogen levels. There was no significant difference in plasma level of albumin.

CONCLUSIONS

Thus, M. maderaspatana leaf-tea consumption gradually decreased BP and showed beneficial effects on blood lipid profile, fibrinogen, bilirubin, and body mass index in patients with hypertension.

Protective effect of Umbelliferone on membranous fatty acid composition in streptozotocin-induced diabetic rats

Umbelliferone (UMB), a natural antioxidant, is benzopyrone in nature, and it is present in the fruits of golden apple and bitter orange. Earlier we evaluated and reported the effect of Umbelliferone on antidiabetic, antioxidant and antihyperlipidemic properties, and this study was designed to evaluate the effect of Umbelliferone on membrane fatty acid composition and histopathology of liver and kidney of control and streptozotocin (STZ) diabetic rats. Male albino Wistar rats (180-200 g) were made diabetic by an intraperitonial administration of STZ (40 mg/kg). The control and diabetic rats were treated with Umbelliferone and glibenclamide dissolved in 10% dimethyl sulfoxide for 45 days. Diabetic rats had decreased insulin and increased glucose, and increased levels of thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes. The levels of palmitic, stearic and oleic acids increased and the levels of linolenic and arachidonic acids decreased in diabetic rats as compared with control rats. Thus, the saturated fatty acids and monounsaturated fatty acids increased and the polyunsaturated fatty acids decreased in diabetic rats. Diabetic rats had decreased liver weight and increased activities of alanine transaminase and aspartate transaminase; increased kidney weight and urine albumin, and decreased levels of urea, uric acid and creatinine in the urine. Histopathological studies of liver and kidney in diabetic rats showed fatty changes surrounding portal triad; enlargement of lining cells of tubules, fatty infiltration, large area of hemorrhage and lymphocyte infiltration. Treatment with Umbelliferone and glibenclamide reversed these changes to near normalcy. Our results showed that Umbelliferone has a protective effect on membrane fatty acid composition of liver and kidney as supported by antioxidant and antihyperlipidemic effects of Umbelliferone reported earlier as evidenced by improved histopathological changes, hepatic and nephritic markers, indicating recovery from the risk of diabetic complications.

Antihyperglycemic Effect of Umbelliferone in Streptozotocin-Diabetic Rats

The present study was designed to investigate the antihyperglycemic effect of Umbelliferone (UMB) in normal and streptozotocin (STZ)-diabetic rats. Diabetes was induced in adult male albino rats of the Wistar strain, weighing 180-200 g, by administration of STZ (40 mg/kg of body weight) intraperitoneally. Diabetic rats showed an increase in levels of blood glucose and glycosylated hemoglobin (HbA(1c)) and activities of gluconeogenic enzymes such as glucose-6-phosphatase and fructose-1,6-bisphosphatase, and a decrease in levels of plasma insulin, hemoglobin (Hb), and liver glycogen and activities of glucokinase and glucose-6-phosphate dehydrogenase. Intraperitoneal administration of UMB (10, 20, and 30 mg/kg of body weight) and glibenclamide (600 micro g/kg of body weight) in 10% dimethyl sulfoxide dissolved in water, for 45 days, produced significantly decreased levels of blood glucose and HbA(1c) and activities of glucose-6-phosphatase and fructose-1,6-bisphosphatase, while elevating levels of plasma insulin, Hb, and liver glycogen and activities of glucokinase and glucose-6-phosphate dehydrogenase to near normal levels in STZ-diabetic rats when compared with normal control rats. Normal rats treated with UMB (30 mg/kg of body weight) also showed a significant effect on glycemic control. Thus, our results show that UMB at 30 mg/kg of body weight possesses a promising antihyperglycemic effect that is comparable with glibenclamide.

A pilot study of open label sesame oil in hypertensive diabetics

The objective of this study was to investigate the effect of sesame oil in hypertensive diabetics medicated with atenolol (beta-blocker) and glibenclamide (sulfonylurea). This open label trial with two intervention periods comprised 22 male and 18 female patients, 45-65 years old, with mild to moderate hypertension and diabetes. Sesame oil (Idhayam Gingelly oil, V.V.V. & Sons, Virudhunagar, Tamilnadu, India) was supplied to the patients, who were instructed to use it in place of other cooking oils for 45 days. Blood pressure (BP), anthropometric measurements, plasma glucose, glycated hemoglobin (HbA1c), lipid profiles [total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol, and triglycerides (TG)], lipid peroxidation [thiobarbituric acid-reactive substances (TBARS)], electrolytes (sodium, potassium, and chloride), and enzymic (superoxide dismutase, glutathione peroxidase, and catalase) and nonenzymic (vitamin C, vitamin E, beta-carotene, and reduced glutathione) antioxidants were measured at baseline and after 45 days of sesame oil substitution. The same patients were then switched over to other oils like palm or groundnut oils as their regular oils at random for another 45 days, and the investigations were carried out again at the end. Systolic and diastolic BP decreased remarkably. When oil substitution was withdrawn, BP values rose again. Body weight, body mass index, girth of waist, girth of hip, and waist:hip ratio were reduced upon substitution of sesame oil. Plasma glucose, HbA1c, TC, LDL-C, and TG were decreased. TBARS level was reduced, while the activities of enzymic and the levels of nonenzymic antioxidants were increased. Plasma sodium levels were reduced, while potassium levels were elevated. These results indicate that substitution of sesame oil as the sole edible oil has an additive effect in further lowering BP and plasma glucose in hypertensive diabetics.

Antihyperglycemic activity of Piper betle leaf on streptozotocin-induced diabetic rats

Piper betle, an indigenous medicinal plant, has a folk (Siddha and Ayurvedha) reputation in the rural southern India. The present study was carried out to evaluate the effect of P. betle on glucose metabolism since it is consumed as betel-quid after meals. Plasma levels of glucose and glycosylated hemoglobin and activities of liver hexokinase and gluconeogenic enzymes such as glucose-6-phosphatase and fructose-1,6-bisphosphatase in control and streptozotocin (STZ) diabetic rats were assayed. Oral administration of leaf suspension of P. betle (75 and 150 mg/kg of body weight) for 30 days resulted in significant reduction in blood glucose (from 205.00 +/- 10.80 mg/dL to 151.30 +/- 6.53 mg/dL) and glycosylated hemoglobin and decreased activities of liver glucose-6-phosphatase and fructose-1,6-bisphosphatase, while liver hexokinase increased (P < .05), in STZ diabetic rats when compared with untreated diabetic rats. P. betle at a dose of 75 mg/kg of body weight exhibited better sugar reduction than 150 mg/kg of body weight. In addition, protection against body weight loss of diabetic animals was also observed. The effects produced by P. betle were compared with the standard drug glibenclamide. Thus, the present study clearly shows that P. betle intake influences glucose metabolism beneficially.

Antioxidant role of Umbelliferone in STZ-diabetic rats

The objective of the study was to investigate the role of Umbelliferone (UMB) on lipid peroxidation, nonenzymic and enzymic antioxidants in the plasma and liver of streptozotocin (STZ)-induced diabetic rats. Adult male albino rats of Wistar strain, weighing 180-200 g, were induced diabetes by administration of STZ (40 mg/kg b.wt.) intraperitoneally. The normal and diabetic rats were treated with UMB (30 mg/kg b.wt.) dissolved in 10% dimethyl sulfoxide (DMSO) for 45 days. Diabetic rats had an elevation in the levels of lipid peroxidation markers (thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (HP) and conjugated dienes (CD)), and a reduction in nonenzymic antioxidants (vitamin C and reduced glutathione (GSH) except vitamin E in the plasma and liver, and enzymic antioxidants (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in the liver. Decreased level of beta-carotene and increased level of ceruloplasmin (Cp) were observed in the plasma of diabetic rats. Treatment with UMB and glibenclamide brought back lipid peroxidation markers, nonenzymic and enzymic antioxidants to near normalcy. Since UMB treatment decreases lipid peroxidation markers and enhances antioxidants' status it can be considered as a potent antioxidant.