Research Statement
With changing food habits and lifestyles the incidence of diabetes mellitus is on the rise. So far, in spite of certain claims made, there are no recorded instances of complete recovery from the disease. The current therapies available have multiple side effects and one major drawback is a need to increase dosage over a time period owing to enhanced insulin resistance in Type II diabetes. There is, therefore, a dire need to develop alternate therapies with minimal side effects and better efficacy. Further diabetes associated imbalance in blood glucose level is responsible for serious secondary complications, like Neuropathy, Nephropathy retinopathy and cardiovascular diseases. The principal cause leading to diabetic complication is due to a non-enzymatic reaction of glucose and proteins. This glycation process leads to formation of highly cross-linked irreversible compounds, called advanced glycation end products (AGEs). Keeping these facts in mind I continued my research career at doctoral and postdoctoral level in the meadow of diabetes. Postdoctoral Research In this study we focused on the AGE modified proteins which are the main culprit of the diabetic complications. Using Anti-AGE antibodies, we have detected the proteins modified by AGEs from the kidney of streptozotocin-induced diabetic rat by using two-dimensional electrophoresis coupled with western blot analysis. These proteins were characterized for glycation modification by using peptide mass fingerprinting and tandem mass spectrometric approaches. We have comprehensively analyzed the glycation of kidney proteins from STZ-induced diabetic and control rats. The numbers of glycated proteins detected in the diabetic kidney were more than that of control. Additionally, the extent of glycation was higher in few glycated proteins that were present in both control and diabetic kidney. Moreover, some of these glycated proteins were found to be up regulated in diabetes. Functional characterization of such glycated proteins may help better in understanding their role in development of nephropathy (Chougale et al., 2012). Further, glycation induced protease resistance in the STZ-induced diabetic rat kidney was studied. AGE modified proteins showed resistance to trypsin digestion. The accumulation of these proteins was found to be due to impairment of the proteasome in the diabetic kidney. Hence, it ultimately leaded to the accumulation of ubiquitinated proteins in the diabetic kidney. The presence of AGEs and ubiquitination in the trypsin resistant proteins was detected by Anti-AGE and Anti-ubiquitin antibody. To gain further insight into the proteins which are affected by proteasomal impairment, LC-MSE analysis was done for identification and characterization of glycated and ubiquitinated proteins. Some of the identified proteins were selected for their functional characterization. Expression analysis of the some of the proteins was also done by western blotting and real time PCR. These findings shed light on the proteins other than long lived proteins which can form aggregates and lose their function due to Glycation reaction in diabetic condition (Bansode et al., 2012). As AGE modification leads to protein aggregation the study of the anti-glycation and cross link inhibitors were undertaken. We reveal the drug which could inhibit the crosslink formation and having glycation protecting activity (MS under preparation). Doctoral Research An Ayurvedic formulation containing 14 plant components was analyzed for anti-diabetic activity. This formulation was suggested by a leading Ayurvedic practitioner. On finding good hypoglycemic activity for the total formulation, it was evaluated for insulin mimetic action, insulin secretogogue action, aldose reductase inhibition, alpha glucosidase inhibition and regenerative capacity. On finding insulin mimetic action, each plant was screened and active plant detected. The mimetic action of the active plant (Tinospora cordifolia) was confirmed by in vivo experiments, glycogenesis in liver and diaphragm tissue, uptake of deoxyglucose and formation of deoxyglucose 6- phosphate and studies on 3T3 adipocyte cell line differentiation. Also the various extract of Tinospora cordifolia shows the noncompetitive type of alpha glucosidase inhibition and able to reduce the blood glucose level of diabetic animals during oral glucose tolerance test (OGTT). (Chougale et al., 2009). Further, a detailed chemical and physical analysis of the active plant component was attempted and tentative structure proposed. The active component was evaluated in comparison with insulin, metformin action and effect of fatty acids, which suggested a post insulin receptor action for the active component. Currently efforts are ongoing to patent the findings. - Detailed publications are listed in CV |
|