A New Antidiabetic Agent Showing Short- and Long-Term Effects Due to Peroxisome Proliferator-Activated Receptor Alpha/Gamma Dual Agonism and Mitochondrial Pyruvate Carrier Inhibition

A new series of analogues or derivatives of the previously reported PPARα/γ dual agonist LT175 allowed the identification of ligand 10, which was able to potently activate both PPARα and -γ subtypes as full and partial agonists, respectively. Docking studies were performed to provide a molecular explanation for this different behavior on the two different targets. In vivo experiments showed that this compound induced a significant reduction in blood glucose and lipid levels in an STZ-induced diabetic mouse model displaying no toxic effects on bone, kidney, and liver. By examining in depth the antihyperglycemic activity of 10, we found out that it produced a slight but significant inhibition of the mitochondrial pyruvate carrier, acting also through insulin-independent mechanisms. This is the first example of a PPARα/γ dual agonist reported to show this inhibitory effect representing, therefore, the potential lead of a new class of drugs for treatment of dyslipidemic type 2 diabetes.

Effect of parthenolide, an NLRP3 inflammasome inhibitor, on insulin resistance in high-fat diet-obese mice

The activation of Nod-like receptor proteins (NLRP3) containing the pyrin domain inflammasome is a hallmark of the pathogenesis of metabolic disorders. Inhibition of the NLRP3 inflammasome by phytoconstituents has been attempted as a strategy to mitigate these disorders. Therefore, the present study aimed to evaluate the efficacy of an NLRP3 inflammasome inhibitor, parthenolide (PN; 5 mg/kg i.p.) against inflammation and insulin resistance in high-fat diet (HFD) - obese mice. Treatment with PN and pioglitazone (PIO; 30 mg/kg p.o.) attenuated lipopolysaccharide (LPS; 1 ng/ml) - induced elevation of tumor necrosis factor-α and interleukin-1β in mouse peritoneal macrophages in a dose-dependent manner. Sixty days of PN and PIO treatment marginally reduced obesity-induced insulin resistance in HFD-obese mice. PN treatment also decreased blood glucose from 14th to 60th day, supporting the hypothesis of simultaneous attenuation of inflammation and insulin resistance in obese mice. Thus, PN treatment was also evident with significant improvement in glucose tolerance and peripheral insulin resistance validated through the respective tolerance tests. Therefore, the present study suggests that PN, an NLRP3 inflammasome inhibitor, could be a possible therapeutic agent for attenuating obesity-induced insulin resistance.

Recombinant irisin induces weight loss in high fat DIO mice through increase in energy consumption and thermogenesis

OBJECTIVE

Irisin is known to be an important metabolic regulator of glucose and lipid metabolism. The aims of the present study are to assess the role of mouse Irisin in obesity and energy metabolism and its glucose and lipid-lowering effects in a high-fat diet-induced obesity (DIO) mice model.

METHODS

DIO mice were treated with recombinant murine Irisin or vehicle, and parameters such as body weight, feed intake, glucose, and lipid levels, obesity, energy consumption, and insulin sensitivity were assessed. mRNA and protein levels of UCP1 and different thermogenesis biomarker were evaluated by quantitative real-time PCR and Western blot, respectively, in tissues and major metabolic organs.

RESULTS

Irisin decreased body weight and whole-body fat mass in DIO mice in a dose dependent manner due to marked increases in total energy expenditure. It also lowered blood glucose, insulin, and lipid levels and possibly reversed hepatic steatosis. Irisin improved hepatic and peripheral insulin sensitivity in DIO mice along with body weight reduction and adiposity. Gene expression of UCP1 in different organs (adipose tissue and major organs, i.e., liver, kidney, heart, brain, and spleen) have suggested the role of irisin is global. Gene expression profile of different biomarkers in spleen suggest a profound role of Irisin in inflammation. Liver tissue have also shown significant increase of UCP1 expression in dose dependent manner which suggest a role of irisin in liver.

Conceptualizing a Model for Improving Access to Medicines in Rural India

India’s health care infrastructure has not kept pace with the economy’s growth. Today only 25 per cent of the Indian population has access to allopathic medicine, practiced mainly in urban areas. Rural India’s health is supported, not always adequately, by the government’s National Rural Health Mission (NRHM).

 This study proposes a model for distributing free medicines to villages. Medicines, a few months before their expiry dates, normally wasted, would be obtained from urban stockists/chemists. Pharmaceutical companies, by giving their consent, could partner with the model. The transfer of drugs to rural India would be via the widespread Indian postal network. Non-governmental organizations (NGOs), postal employees and trained NRHM personnel would mobilize the model. Such a public–private partnership brings together members of civil society (e.g., NGOs), public sector (e.g., government agencies) and private sector (e.g., pharmaceutical companies) to fund, coordinate and drive the model, addressing the gaps in rural access to health care.

Abstract 609: Pharmacological Inhibition of NLRP3 Inflammasome by Parthenolide Improves Obesity-Induced Insulin Resistance in Diet-Induced Obese Mice

Many landmark studies have reported the Nod-like receptor proteins containing Pyrin domain (NLRP3) inflammasome activation in metabolic diseases that include obesity, atherosclerosis and type 2 diabetes. Therefore, the present study was aimed: (i) to determine the role of NLRP3 in inflammation and insulin resistance in high fat diet-induced obesity (DIO) model of mice, and (ii) to determine whether parthenolide, a NLRP3 inhibitor, is able to protect mice against inflammation and insulin resistance in high fat DIO model.

METHODS: Lipopolysaccharide (1 ng/ml) primed mouse intraperitoneal macrophages were treated with Parthenolide (0.1 to 30 μM) to evaluate its effect on TNF-α and IL-1β. Parthenolide and Pioglitazone were administered to DIO mice (fed 60% high fat diet) at 5 and 30 mg/kg QD, PO, respectively for 60 days to evaluate their effect on insulin resistance.

RESULTS: Parthenolide (5 mg/kg) markedly attenuated inflammatory cytokines as evidenced by significant and dose dependant inhibition of both TNF-α and IL-1β in LPS primed macrophages. Treatment also lowered the fed blood glucose from day 14 to the entire course of study supporting the hypothesis that attenuating inflammation would be a possible intervention to insulin resistance. Parthenolide also improved peripheral insulin resistance, as demonstrated by insulin tolerance test and a significant improvement in the glucose intolerance as demonstrated by the oral glucose tolerance test. Moreover, treatment lowered plasma insulin levels indicating a trend in the improvement in insulin sensitivity.

CONCLUSIONS: Collectively, obtained results support our hypothesis that Parthenolide, an inflammasome inhibitor, could be a useful agent in antagonizing obesity-induced insulin resistance

Discovery of a potent and selective small molecule hGPR91 antagonist

GPR91, a 7TM G-Protein-Coupled Receptor, has been recently deorphanized with succinic acid as its endogenous ligand. Current literature indicates that GPR91 plays role in various pathophysiology including renal hypertension, autoimmune disease and retinal angiogenesis. Starting from a small molecule high-throughput screening hit 1 (hGPR91 IC(50): 0.8 μM)-originally synthesized in Merck for Bradykinin B(1) Receptor (BK(1)R) program, systematic structure-activity relationship study led us to discover potent and selective hGPR91 antagonists e.g. 2c, 4c, and 5 g (IC(50): 7-35 nM; >1000 fold selective against hGPR99, a closest related GPCR; >100 fold selective in Drug Matrix screening). This initial work also led to identification of two structurally distinct and orally bio-available lead compounds: 5g (%F: 26) and 7e (IC(50): 180 nM; >100 fold selective against hGPR99; %F: 87). A rat pharmacodynamic assay was developed to characterize the antagonists in vivo using succinate induced increase in blood pressure. Using two representative antagonists, 2c and 4c, the GPR91 target engagement was subsequently demonstrated using the designed pharmacodynamic assay.