Identification of novel human neutrophil elastase inhibitors from dietary phytochemicals using in silico and in vitro studies.

Human neutrophil elastase (HNE) has been well studied as a therapeutic target for inflammatory diseases for several decades. A variety of small-molecule HNE inhibitors have been well known, and their mode of binding at the active site of the enzyme has been determined, but none of them reached clinical trials except sivelestat. In this study, we intended to identify potent dietary phytochemicals that can target the active site of HNE by employing computational methods and in vitro inhibition assay. Database retrieval and preparation, structure-based virtual screening and molecular docking, rescoring, free energy calculations, adsorption, distribution, metabolism, and excretion (ADME) predictions and an in vitro assay were conducted to propose a collection of biochemically active molecules with the potential for inhibition against HNE. Overall, 167,504 secondary metabolites originating from the plants were docked. Of these, five natural compounds with drug-like properties have shown remarkable docking profiles to HNE. These hit candidates were then examined for validation through an HNE inhibition assay. The results showed that troxerutin (TX) had better binding efficacy with HNE followed by oleuropein, scutellarin, hesperidin and gossypin. These phytochemicals are present in relatively common fruits and vegetables, indicating the potential for safe and affordable inflammatory disease therapy.HighlightsTroxerutin shows the highest HNE binding affinity in computational analysis.HIS A: 57 is the major contributor to the protein-ligand interaction.Flavonoids exhibit binding efficacy against HNE.Flavonoids may serve as potent inhibitors for HNE.Communicated by Ramaswamy H. Sarma.

Anti-inflammatory effects of troxerutin are mediated through elastase inhibition.

CONTEXT: Obesity is a chronic low-grade inflammatory state associated with immune cell infiltration into the adipose tissue (AT). We hypothesize that the anti-obesity and anti-inflammatory effects of troxerutin (TX) are mediated through inhibition of elastase. OBJECTIVE: To determine the inhibitory effect of TX on elastase in vitro and in tumor necrosis factor alpha (TNFα) induced 3T3-L1 adipocytes and the molecular interaction of TX with human neutrophil elastase (HNE). MATERIALS AND METHODS: Differentiated 3T3-L1 adipocytes were pretreated with TX, elastatinal (ELAS) or sodium salicylate (SAL) before exposure to TNFα. Lipid accumulation, reactive oxygen species (ROS) generation and oxidant-antioxidant balance were examined. The mRNA and protein expression of TNFα, interleukin-6, monocyte chemoattractant protein-1, adiponectin, leptin, resistin, chemerin, and elastase were analyzed. Elastase inhibition by TX and ELAS in a cell free system and docking studies for HNE with TX and ELAS were performed. RESULTS: TX, ELAS or SAL pretreatment had lowered lipid droplets formation and TG content. TX suppressed ROS generation, oxidative stress and improved antioxidant status. The expression of inflammatory cytokines and elastase was downregulated while that of adiponectin was upregulated by TX. The concentration required to produce 50% inhibition in vitro (IC50) was 11.5 µM for TX and 16.9 µM for ELAS. TX showed hydrogen bonding and hydrophobic interactions with elastase. DISCUSSION: TNFα induces inflammation of 3T3-L1 cells through elastase activation. TX inhibits elastase activity, downregulates expression and binds with elastase. CONCLUSION: The antioxidant and anti-inflammatory activities of TX in AT could be of relevance in the management of obesity.

Oxidative stress, antioxidant status and lipid profile in pulmonary tuberculosis patients before and after anti-tubercular therapy.

BACKGROUND: Pulmonary tuberculosis (PTB) is a highly infectious dreadful disease caused by mycobacterium tuberculosis (MTB). Numerous studies reported free radicals activity, antioxidant status and lipid profile in PTB patients, but previous studies have lacunae in comparing the biochemical variables between before and after anti-tubercular therapy (ATT) supplementation to PTB patients. Hence, the present study was carried out to investigate oxidative stress markers, antioxidant status, lipid profile, liver function markers, and glycoprotein components in pulmonary tuberculosis patients (PTB) patients before and after 60 days of ATT. METHODS: This is a case-control study carried out with 100 healthy subjects and 110 PTB patients. All the patients diagnosed with sputum test and were positive for acid fast bacilli (AFB) were included for the study. An informed consent was obtained from all the patients. RESULTS: Our study found increased levels of oxidative stress markers, decreased enzymatic and non-enzymatic antioxidants, altered lipid profile in PTB patients as compared to healthy subjects before treatment and these levels were restored after clinical improvement with ATT. We also found increased concentrations of liver function parameters and components of glycoprotein in PTB patients. ATT refurbished lipid levels, antioxidant status and oxidative stress markers with decrease in liver function enzymes and glycoproteins in PTB patients. CONCLUSION: Co-supplementation of antioxidants, along with ATT and inclusion of nutritious diet could be useful to reduce the pathogenesis of PTB and is warranted as a future study for the management of PTB.

Supplementation of scopoletin improves insulin sensitivity by attenuating the derangements of insulin signaling through AMPK.

Scopoletin (SPL), a phenolic coumarin, is reported to regulate glucose metabolism. This study is initiated to substantiate the action of SPL on the regulation of insulin signaling in insulin resistant RIN5f cells and high fat, high fructose diet (HFFD)-fed rat model. Adult male Sprague Dawley rats were fed HFFD for 45 days to induce type 2 diabetes and then treated or untreated with SPL for the next 45 days. The levels of glucose, insulin, lipid profile, oxidative stress markers along with insulin signaling and AMPK protein expressions were examined at the end of 90 days. SPL lowered the levels of plasma glucose, insulin, and lipids which were increased in HFFD-fed rats. HFFD intake suppressed the activities of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase; however, they were reversed by SPL supplementation, which reduced TBARS, lipid hydroperoxide, and protein carbonyl levels both in plasma and pancreas. SPL supplementation significantly activated insulin receptor substrate 1 (IRS1), phosphatidyl inositol 3-kinase (PI3K), and protein kinase B (Akt) phosphorylation which was suppressed in HFFD rats due to lipotoxicity. Moreover, SPL significantly activated AMPK and enhanced the association of IRS1-PI3K-Akt compared to the control group. The results revealed that SPL alleviated T2D induced by HFFD by escalating the antioxidant levels and through insulin signaling regulation. We conclude that SPL can improve insulin signaling through AMPK, thereby confirming the role of SPL as an AMPK activator.

Prevalence of dry eye disease and its association with dyslipidemia.

BACKGROUND: Dry eye disease (DED) is a common ocular surface disease significantly affecting the quality of life of patients. The aim of our study is to focus on the prevalence of DED and to determine the relationship between dyslipidemia and DED. METHODS: The study was performed with the age group of 25-70 years, who attended the ophthalmology outpatient department at Sri Lakshmi Narayana Institute of Medical Sciences with complaints of dry eye. A standard questionnaire was taken, and tear film tests were performed to diagnose dry eye. Further eyelid margin was examined to detect meibomian gland dysfunction. Based on the tests and examination, patients were grouped as men with and without DED and women with and without DED. Fasting lipid profile was investigated for these groups. RESULTS: The study showed the prevalence of DED mainly in women and found significant association between DED and dyslipidemia. There is a significant relationship between total cholesterol and DED groups especially in women (p<0.001). We also found the association between triglycerides, high density lipoprotein cholesterol, low density lipoprotein cholesterol and DED particularly in women as compared to men. CONCLUSIONS: Based on the findings, we emphasize that there is a strong relationship between dyslipidemia and the progression of DED particularly in women. Ophthalmologists may increase their role to educate themselves to diagnose dyslipidemia and ensure comprehensive eye care to prevent blindness and cardiovascular disease. Recent treatment modalities could be aimed to improve the quality of life of women and elderly patients suffering from DED.