Christudas Sunil

Antidiabetic and antioxidant activities of Toddalia asiatica (L.) Lam. leaves in streptozotocin induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE The leaves of Toddalia asiatica (L.) Lam. have been utilized traditionally for the cure of diabetes. AIM OF THE STUDY The present study was aimed to assess the antidiabetic and antioxidant effects of T. asiatica leaves in Streptozotocin (STZ) induced diabetic rats. MATERIALS AND METHODS The phytochemical screening, total phenolic content, HPLC analysis, acute toxicity study and oral glucose tolerance test were carried out. Glucose lowering effect of the hexane, ethyl acetate and methanol extracts of T. asiatica leaves was studied in STZ-induced diabetic rats. The antidiabetic and antioxidant activities were studied for the ethyl acetate extract. The effects of extracts on blood glucose, body weight, plasma insulin, total protein, liver glycogen, plasma enzymes (SGOT, SGPT and ALP) and activities of SOD, CAT and GPx were analyzed. RESULTS T. asiatica leaves ethyl acetate extract (TALEe) showed highly significant blood glucose lowering effect. Phytochemical evaluation of TALEe showed the presence of alkaloids, terpenoids, cumarins, flavonoids and phenolic compounds. The total phenolic content of TALEe was 126 mg of gallic acid equivalents/g extract. HPLC analysis revealed the presence of flindersine and ulopterol. Acute toxicity study of TALEe revealed no death or toxicity. The oral glucose tolerance test showed lowered area under curve (AUC(glucose)) values in TALEe treated rats. After treatment with TALEe (250 and 500 mg/kg) for 28 days there was a significant decrease in blood glucose, plasma enzymes (SGOT, SGPT and ALP) and significant increase in body weight, total protein, serum insulin and liver glycogen levels in treated diabetic rats. The activities of antioxidant enzymes SOD, CAT and GPx were reversed to near normal in treated diabetic rats. Histopathology of pancreas in TALEe treated groups showed regeneration of β-cells. CONCLUSION The results of the experiments showed that TALEe exerted significant antidiabetic and antioxidant effects in STZ-induced diabetic rats justifying its traditional use.

Antidiabetic effect of plumbagin isolated from Plumbago zeylanica L. root and its effect on GLUT4 translocation in streptozotocin-induced diabetic rats.

Plumbago zeylanica L. root is widely used in Indian medicine to treat diabetes mellitus. The aim of the present investigation was to evaluate the antidiabetic effects of plumbagin isolated from P. zeylanica L. root and its effect on GLUT4 translocation in STZ-induced diabetic rats. Plumbagin (15 and 30 mg/kg b wt) was orally administered to STZ-induced diabetic rats for 28 days. An oral glucose tolerance test was performed on 21st day. The effect of plumbagin on body weight, blood glucose, plasma insulin, total protein, urea, creatinine, liver glycogen, plasma enzymes (SGOT, SGPT and ALP) and carbohydrate metabolism enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase and hexokinase) were investigated. GLUT4 mRNA and protein expression in skeletal muscles were also studied. Plumbagin significantly reduced the blood glucose and significantly altered all other biochemical parameters to near normal. Further, plumbagin increased the activity of hexokinase and decreased the activities of glucose-6-phosphatase and fructose-1,6-bisphosphatase significantly in treated diabetic rats. Enhanced GLUT4 mRNA and protein expression were observed in diabetic rats after treatment with plumbagin. The results indicated that plumbagin enhanced GLUT4 translocation and contributed to glucose homeostasis. It could be further probed for use as a drug to treat diabetes.

Effect of Biophytum sensitivum on streptozotocin and nicotinamide-induced diabetic rats

OBJECTIVE To investigate the effect of aqueous solution of Biophytum sensitivum leaf extract (BSEt) on normal and streptozotocin (STZ)-nicotinamide-induced diabetic rats. METHODS Diabetes was induced in adult male Wistar rats by the administration of STZ-nicotinamide (40, 110 mg/kg b.w., respectively) intraperitoneally. BSEt (200 mg/kg) was administered to diabetic rats for 28 days. The effect of extract on blood glucose, plasma insulin, total haemoglobin, glycosylated haemoglobin, liver glycogen and carbohydrate metabolism regulating enzymes of liver was studied in diabetic rats. RESULTS BSEt significantly reduced the blood glucose and glycosylated haemoglobin levels and significantly increased the total haemoglobin, plasma insulin and liver glycogen levels in diabetic rats. It also increased the hexokinase activity and decreased glucose-6-phosphatase, fructose-1, 6-bisphosphatase activities in diabetic rats. CONCLUSIONS The results of our study suggest that BSEt possesses a promising effect on STZ-nicotinamide-induced diabetes.

In vitro antioxidant, antidiabetic and antilipidemic activities of Symplocos cochinchinensis (Lour.) S. Moore bark.

Symplocos cochinchinesis is used in Indian system of traditional medicine to treat diabetes mellitus. The present study investigates the in vitro antioxidant, antidiabetic and antilipidemic activities of S. cochinchinensis bark methanolic extract (SCBe) in streptozotocin (STZ) induced diabetic rats. In in vitro studies SCBe showed very good scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC(50) 820.34 ± 1.74 μg/ml), hydroxyl (IC(50) 884.19 ± 0.45 μg/ml) and nitric oxide (IC(50) 860.21 ± 1.18 μg/ml) radicals, as well as high reducing power. SCBe (250 and 500 mg/kg) was administered to STZ (40 mg/kg) induced diabetic rats for 28 days. SCBe showed a significant decrease in blood glucose and significant increase in plasma insulin and liver glycogen levels in treated diabetic rats. Further, SCBe showed antilipidemic activity as evidenced by significant decrease in serum TC, TG, LDL-C levels and significant increase in HDL-C level in treated diabetic rats. SCBe also restored the altered plasma enzymes (SGOT, SGPT and ALP), total protein, urea and creatinine levels to near normal. The action of SCBe was comparable to the antidiabetic drug glibenclamide. Results of this experimental study indicated that SCBe possessed antioxidant, antidiabetic and antilipidemic activities.

Antioxidant, free radical scavenging and liver protective effects of friedelin isolated from Azima tetracantha Lam. leaves.

The aim of the present study was to evaluate the antioxidant, free radical scavenging and liver protective effects of friedelin isolated from Azima tetracantha Lam. leaves. In in vitro antioxidant study, the free radical scavenging effect of friedelin on 2,2-diphenyl-picrylhydrazyl (DPPH), hydroxyl, nitric oxide and superoxide radicals were evaluated. Friedelin showed very good scavenging effect on DPPH (IC50 21.1 mM), hydroxyl (IC50 19.8 mM), nitric oxide (IC50 22.1 mM) and superoxide (IC50 21.9 mM) radicals. Friedelin also showed strong suppressive effect on lipid peroxidation. In in vivo antioxidant study, CCl4 induced oxidative stress on rats produced significant increase in serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT) and lactate dehydrogenase (LDH) levels along with reduction in liver superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and glutathione peroxidase (GPx) levels. Pre-treatment of rats with friedelin at 40 mg/kg for 7 days restored these levels to normality and showed liver protection, comparable to the standard, silymarin (25 mg/kg). These results clearly demonstrated that friedelin possessed marked antioxidant and liver protective effects.

In vitro and in vivo antioxidant activity of Symplocos cochinchinensis S. Moore leaves containing phenolic compounds.

Methanol extract of Symplocos cochinchinensis S. Moore leaves was evaluated for its in vitro and in vivo antioxidant activity. The total phenolic content of the extract was 230 mg of gallic acid equivalents/g extract. The extract showed very good scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC50 620.30 ± 0.14 μg/ml), hydroxyl (IC50 730.21 ± 1.05 μg/ml), nitric oxide (IC50 870.31 ± 0.19 μg/ml) radicals, as well as high reducing power. The extract also showed strong suppressive effect on lipid peroxidation. In in vivo study CCl4 induced oxidative stress produced significant increase in SGOT, SGPT and LDH levels along with reduction in liver SOD, CAT, GSH and GPx levels. Pre-treatment of rats with the extract (250 and 500 mg/kg) for 7 days showed significant reduction in the levels of SGOT, SGPT and LDH compared to CCl4 treated rats. SOD, CAT, GSH and GPx levels were increased significantly due to treatment with the extract. The activity of the extract was comparable to the standard drug, silymarin (25 mg/kg). The results suggest that the leaves of S. cochinchinensis are a source of natural antioxidants.

In vitro studies on α-glucosidase inhibition, antioxidant and free radical scavenging activities of Hedyotis biflora L.

Aim of this study was to evaluate the in vitro α-glucosidase inhibition and antioxidant activity of hexane, ethyl acetate and methanol extracts of Hedyotis biflora L. (Rubiaceae). In in vitro α-glucosidase inhibition and antioxidant activity, the methanol extract showed potent effect compared to hexane and ethyl acetate extracts. The methanol extract of H. biflora (HBMe) showed 50% α-glucosidase inhibition at the concentration of 480.20 ± 2.37 μg/ml. The total phenolic content of HBMe was 206.81 ± 1.11 mg of catechol equivalents/g extract. HBMe showed great scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC(50) 520.21 ± 1.02 μg/ml), hydroxyl (IC(50) 510.21 ± 1.51 μg/ml), nitric oxide (IC(50) 690.20 ± 2.13 μg/ml) and superoxide (IC(50) 510.31 ± 1.45 μg/ml) radicals, as well as high reducing power. HBMe also showed a strong suppressive effect on lipid peroxidation. Using the β-carotene method, the scavenging values of HBMe was significantly lower than BHT, and metal chelating ability of HBMe also showed a strong inhibition effect when compared to the reference standard. The active compound ursolic acid from HBMe was identified using various spectroscopical studies. The results obtained in this study clearly indicate that HBMe has a significant potential to use as a natural α-glucosidase inhibition, antioxidant agent.

In vitro antioxidant and antihyperlipidemic activities of Toddalia asiatica (L) Lam. Leaves in Triton WR-1339 and high fat diet induced hyperlipidemic rats

The present study was undertaken to evaluate the in vitro antioxidant and antihyperlipidemic activity of Toddalia asiatica (L) Lam. leaves in Triton WR-1339 and high fat diet-induced hyperlipidemic rats. In in vitro studies T. asiatica leaves ethyl acetate extract showed very good scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC₅₀ 605.34±2.62 μg/ml), hydroxyl (IC₅₀ 694.37±2.12 μg/ml) and nitric oxide (IC₅₀ 897.83±1.48 μg/ml) radicals, as well as high reducing power. In Triton WR-1339 induced hyperlipidemic rats, oral treatment with T. asiatica leaves ethyl acetate extract produced a significant (P≤0.005) decrease in the levels of serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), and significant increase in high-density lipoprotein cholesterol (HDL-C) in comparison with hexane and methanol extracts. In high fat diet-fed hyperlipidemic rats, the ethyl acetate extract (200 and 400 mg/kg) significantly altered the plasma and liver lipids levels to near normal.