Recombinant Human Epidermal Growth Factor Alleviates Gastric Antral Ulcer Induced by Naproxen: A Non-steroidal Anti Inflammatory Drug

Malabaricone C Attenuates Nonsteroidal Anti-Inflammatory Drug-Induced Gastric Ulceration by Decreasing Oxidative/Nitrative Stress and Inflammation and Promoting Angiogenic Autohealing

Aims: Nonsteroidal anti-inflammatory drugs (NSAIDs), among the most commonly used drugs worldwide, are associated with gastrointestinal (GI) complications that severely limit the clinical utility of this essential class of pain medications. Here, we mechanistically dissect the protective impact of a natural product, malabaricone C (Mal C), on NSAID-induced gastropathy. Results: Mal C dose dependently diminished erosion of the stomach lining and inflammation in mice treated with NSAIDs with the protective impact translating to improvement in survival. By decreasing oxidative and nitrative stress, Mal C treatment prevented NSAID-induced mitochondrial dysfunction and cell death; nuclear factor κ-light-chain enhancer of activated B cell induction, release of proinflammatory cytokines and neutrophil infiltration; and disruptions in the vascular endothelial growth factor/endostatin balance that contributes to mucosal autohealing. Importantly, Mal C failed to impact the therapeutic anti-inflammatory properties of multiple NSAIDs in a model of acute inflammation. In all assays tested, Mal C proved as or more efficacious than the current first-line therapy for NSAID-dependent GI complications, the proton pump inhibitor omeprazole. Innovation: Given that omeprazole-mediated prophylaxis is, itself, associated with a shift in NSAID-driven GI complications from the upper GI to the lower GI system, there is a clear and present need for novel therapeutics aimed at ameliorating NSAID-induced gastropathy. Mal C provided significant protection against NSAID-induced gastric ulcerations impacting multiple critical signaling cascades contributing to inflammation, cell loss, extracellular matrix degradation, and angiogenic autohealing. Conclusion: Thus, Mal C represents a viable lead compound for the development of novel gastroprotective agents.

Physicochemical, pharmacokinetics, and histological evaluation of new naproxen-quercetin co-lyophilizate to diminish drug-induced gastric irritations in rats

Quercetin (QUE) is a flavonoid found in several plants and commonly distributed in edible vegetables and fruits. To evaluate the effect of co-lyophilization of naproxen (NPX) with QUE at different weight ratios on physicochemical characteristics induced gastric irritation, and drug pharmacokinetics. NPX binary systems with QUE in different weight ratios were prepared by freeze-drying alkalinized solutions, and were characterized in terms of physicochemical properties as well as NPX dissolution rate in acidic pH. NPX-induced gastric inflammation studies were carried out in rats for 7 days. The pharmacokinetics of the two formulations were assessed to evaluate the bioavailability of NPX-QUE 1:2 co-lyophilizate. Westar rats were administered oral doses equivalent to 40 mg kg⁻¹ of NPX and blood samples were taken from the retro-orbital vein of rats at 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0 12.0, and 24.0 h post dosing. Co-lyophilization of NPX with QUE enhanced drug dissolution rate in the acidic medium, which was correlated with an increased QUE weight ratio in the co-lyophilizates. Rat stomachs from group V (NPX-QUE 1:2 co-lyophilizate) showed non-significant changes, and biopsies from this group showed no significant leukocyte infiltration and edema in the mucosa. The bioavailability of NPX-QUE 1: 2 co-lyophilizate was similar to the control sample. NPX-QUE 1: 2 co-lyophilizate could be an alternative to NPX in the treatment of arthritis as it minimizes the potential for gastric irritation and enhances safety while retaining the same efficacy and bioavailability.

Islet adaptation to obesity and insulin resistance in WNIN/GR-Ob rats

WNIN/GR-Ob mutant rat is a novel animal model to study metabolic syndrome (obesity, insulin resistance, hyperinsulinemia, impaired glucose tolerance and cardiovascular diseases). We have investigated the islet characteristics of obese mutants at different age groups (1, 6 and 12 months) to assess the islet changes in response to early and chronic metabolic stress. Our data demonstrates altered islet cell morphology and function (hypertrophy, fibrotic lesions, vacuolation, decreased stimulation index, increased TNFα, ROS and TBARS levels) in mutants as compared to controls. Furthermore, network analysis (gene-gene interaction) studied in pancreas demonstrated increased inflammation as a key factor underlying obesity/metabolic syndrome in mutants. These observations pave way to explore this model to understand islet adaptation in response to metabolic syndrome.

Obesity, insulin resistance, and metabolic syndrome: a study in WNIN/Ob rats from a pancreatic perspective

Alterations in pancreatic milieu to adapt to physiological shifts occurring in conditions of obesity and metabolic syndrome (MS) have been documented, though mechanisms leading to such a state have remained elusive so far. The data presented here tries to look at the gravity of metabolic insult during the early and prolonged phases of obesity/insulin resistance (IR) depicted in WNIN/Ob strain of rats—an obese euglycemic mutant rat model developed indigenously at our institute which is highly vulnerable for a variety of degenerative diseases. The present results in situ show the participation of several confounding factors in the pancreatic milieu that collectively coprecipitates for a state of profound inflammation in the pancreas (among Mutant compared to Lean/Control) which gets worsened with age. These include hypertrophy, macrophage infiltration (CD11b/TNFα/IL6), apoptosis, β-cell vacuolation, hyperinsulinemia (HI), and stress markers (RL-77/HSP104/TBARS) all of which correlated well with indices for obesity (2-3 fold), IR (1.5-3 fold), and HI (2-3 fold). Further, supportive data was also obtained from in vitro studies using islet cell cultures amongst phenotypes. Taken together, these results advocate that inflammation was the major precipitating factor to cause islet cell dysfunctions (in situ and in vitro) in these Mutant rats compared to their Lean littermates and parental Control.

Construction of Yeast Recombinant Expression Vector Containing Human Epidermal Growth Factor (hEGF)

PURPOSE

The objective of this study was construction of recombinant hEGF-pPIC9 which may be used for expression of recombinant hEGF in following studies.

METHODS

EGF cDNA was purchased from Genecopoeia Company and used for PCR amplification. Prior to ligation, the PCR product and pPIC9 vector was digested with EcoRI and XhoI and ligated in pPIC9 vector and subjected to colony PCR screening and sequencing analysis.

RESULTS

PCR amplification of EGF cDNA using recombinant hEGF-pPIC9 vector as template was concluded in amplification of 197bp fragment. Construction of recombinant hEGF-pPIC9 of EGf gene was verified by PCR and sequencing.

CONCLUSION

Construction of Recombinant hEGF-pPIC9 was the primary stage for production and expression of EFG in the future study.

Deriving at candidate genes of metabolic stress from pancreas of WNIN/GR-Ob mutant rats

Development of appropriate animal model systems have greatly helped our understanding of the basic mechanism(s) of several degenerative diseases. WNIN/GR-Ob?a mutant rat strain developed at the National Center for Laboratory Animal Sciences facility of National Institute of Nutrition, is a new animal model ideal to study the metabolic syndrome since it is obese with impaired glucose tolerance and also exhibits several secondary complications. The present study was performed in the pancreas of this mutant model to assess the global gene expression (microarray) to assess the transcriptome level changes in situ depicting inflammation, obesity, insulin resistance, and diabetes in these animals. Our findings suggest an interplay of several confounding factors in pancreas which include inflammation /macrophage infiltration/apoptosis/oxidative and endoplasmic reticulum stress, all contributing for the shift toward pro-inflammation. We were able to phenotypically correlate the metabolic alterations vis-a-vis candidate genes (array analyses) compared between mutants and its age matched, parental controls. We advocate that the data reported here would provide a suitable insight in to the pathophysiology of metabolic syndrome .