K.R. Prabhakar

Ficus racemosa Stem Bark Extract: A Potent Antioxidant and a Probable Natural Radioprotector

Ethanol extract (FRE) and water extract (FRW) of Ficus racemosa (family: Moraceae) were subjected to free radical scavenging both by steady state and time resolved methods such as nanosecond pulse radiolysis and stopped-flow spectrophotometric analyses. FRE exhibited significantly higher steady state antioxidant activity than FRW. FRE exhibited concentration dependent DPPH, ABTS•−, hydroxyl radical and superoxide radical scavenging and inhibition of lipid peroxidation with IC50 comparable with tested standard compounds. In vitro radioprotective potential of FRE was studied using micronucleus assay in irradiated Chinese hamster lung fibroblast cells (V79). Pretreatment with different doses of FRE 1h prior to 2 Gy γ-radiation resulted in a significant (P < 0.001) decrease in the percentage of micronucleated binuclear V79 cells. Maximum radioprotection was observed at 20 μg/ml of FRE. The radioprotection was found to be significant (P < 0.01) when cells were treated with optimum dose of FRE (20 μg/ml) 1 h prior to 0.5, 1, 2, 3 and 4 Gy γ-irradiation compared to the respective radiation controls. The cytokinesis-block proliferative index indicated that FRE does not alter radiation induced cell cycle delay. Based on all these results we conclude that the ethanol extract of F. racemosa acts as a potent antioxidant and a probable radioprotector.

Antidiabetic effect of Ficus racemosa Linn. stem bark in high-fat diet and low-dose streptozotocin-induced type 2 diabetic rats: a mechanistic study.

The present study was designed to investigate the effects of the ethanol extract of Ficus racemosa (FRE) on biochemical parameters in type 2-like diabetes, induced by a combination of standardised high-fat diet and low-dose streptozotocin (25mgkg(-1), i.p.) in rats. To elucidate the mode of action of FRE, its effects on a battery of targets involved in glucose homeostasis was evaluated. FRE (200 and 400mgkg(-1), p.o.), in a dose-dependent manner, altered the biochemical parameters and significantly improved glucose tolerance and HDL-c levels. In different bioassays, FRE showed inhibition of PTP-1B (IC50 12.1μg/mL) and DPP-IV (42.5%). FRE exhibited 82.6% binding to PPAR-γ. Furthermore FRE exhibited stimulation of glucose uptake by skeletal muscles (hemi-diaphragm). Bergenin was quantified in bioactive-FRE by high-performance liquid chromatography (0.15%w/w). This is the first report demonstrating the effectiveness of F. racemosa stem bark in type 2 diabetes and targets involved in it.

Antidiabetic effect of Dodonaea viscosa aerial parts in high fat diet and low dose streptozotocin-induced type 2 diabetic rats: A mechanistic approach

Context: High fat diet (HFD) and low-dose streptozotocin (STZ) is an ideal model for type 2 diabetes mellitus (T2DM) that would closely reflect the natural history and metabolic characteristics of human T2DM and is also suitable for pharmacological screening. Objective: The present study was designed to investigate the effect of the water extract (DVW) and the polar fraction of ethanol extract (DVE-4) of Dodonaea viscosa (L). Jacq. (Sapindaceae) on biochemical parameters in type 2 diabetes induced by a standardized HFD and low dose streptozotocin (25 mg/kg) in rats. Further, to elucidate the mode of action we evaluated its effects on a battery of targets involved in glucose homeostasis (in vitro studies). Materials and methods: Different doses of DVW and DVE-4 were administered once daily for two weeks to HFD + STZ diabetic rats. Quantification of biomarker quercetin was done using HPLC. Results and discussion: Both DVW and DVE-4 dose-dependently reduced blood glucose, serum insulin, homeostatic model assessment (HOMA), lipid profiles, and significantly improved glucose tolerance and HDL-c levels. In addition, the extract and fraction also decreased oxidative stress by improving endogenous antioxidants. In different, bioassays, DVW and DVE-4 showed inhibition of PTP-1B and at a concentration of 10 μg/mL showed 60 and 54.2% binding to PPARγ, respectively. Both extract/fraction exhibited stimulation of glucose uptake by skeletal muscles. Conclusion: Taken together, these results suggest that DVW and DVE-4 inhibits HFD + STZ-induced insulin resistance, lipid abnormalities and oxidative stress indicating that these effects may be mediated by interacting with multiple targets operating in diabetes mellitus.

Carotid artery intimal media thickness and ankle brachial index as predictors for atherosclerosis in pre-diabetic patients

Background: Atherosclerosis still remains as the major cause of death and premature disability in developed societies. Insulin resistance is a central pathogenesis feature of prediabetes, the incidence of which is rising substantially. The principal cause of end organ damage in prediabetes is premature cardiovascular atherosclerosis. Objectives: To assess the atherosclerosis in prediabetes. Materials and Methods: Patients who were nondiabetic of age group between 18 and 50 years were screened for fasting blood sugar, post-prandial blood sugar, hemoglobin A1c, after obtaining informed consent and were divided to study group and control group according to inclusion criteria. Results: In this study, abnormal carotid intimal media thickness (CIMT) was observed in 7 (17.1%), out of 41 pre-diabetic patients. This difference in CIMT findings between two groups was statistically significant. Prediabetics are at 8 times higher risk of developing abnormal CIMT than nondiabetics. Abnormal CIMT was associated with greater body mass index, waist-hip ratio, low high-density lipoprotein, high triglycerides, and abnormal ABI. Conclusion: Prediabetes was associated with higher risk of developing subclinical atherosclerosis when compared to non-diabetic patients. Lifestyle modification should be adopted to prevent the conversion of prediabetes into Type 2 diabetes mellitus and thus prevention of its complication.