Effect of Aerobic Exercise and Time-Restricted Feeding on Metabolic Markers and Circadian Rhythm in Mice Fed with the High-Fat Diet

SCOPE

Diet and exercise are significant players in obesity and metabolic diseases. Time-restricted feeding (tRF) has been shown to improve metabolic responses by regulating circadian clocks but whether it acts synergically with exercise remains unknown. It is hypothesized that forced exercise alone or combined with tRF alleviates obesity and its metabolic complications.

METHODS AND RESULTS

Male C57bl6 mice are fed with high-fat or a control diet for 12 weeks either ad libitum or tRF for 10 h during their active period. High-fat diet (HFD)-fed mice are divided into exercise (treadmill for 1 h at 12 m min-1 alternate days for 9 weeks and 16 m min-1 daily for the following 3 weeks) and non-exercise groups. tRF and tRF-Ex significantly decreased body weight, food intake, and plasma lipids, and improved glucose tolerance. However, exercise reduced only body weight and plasma lipids. tRF and tRF-Ex significantly downregulated Fasn, Hmgcr, and Srebp1c, while exercise only Hmgcr. HFD feeding disrupted clock genes, but exercise, tRF, and tRF-Ex coordinated the circadian clock genes Bmal1, Per2, and Rev-Erbα in the liver, adipose tissue, and skeletal muscles.

CONCLUSION

HFD feeding disrupted clock genes in the peripheral organs while exercise, tRF, and their combination restored clock genes and improved metabolic consequences induced by high-fat diet feeding.

Nutrient Combinations Sensed by L-Cell Receptors Potentiate GLP-1 Secretion

Obesity is a risk factor for cardiometabolic diseases. Nutrients stimulate GLP-1 release; however, GLP-1 has a short half-life (<2 min), and only <10-15% reaches the systemic circulation. Human L-cells are localized in the distal ileum and colon, while most nutrients are absorbed in the proximal intestine. We hypothesized that combinations of amino acids and fatty acids potentiate GLP-1 release via different L-cell receptors. GLP-1 secretion was studied in the mouse enteroendocrine STC-1 cells. Cells were pre-incubated with buffer for 1 h and treated with nutrients: alpha-linolenic acid (αLA), phenylalanine (Phe), tryptophan (Trp), and their combinations αLA+Phe and αLA+Trp with dipeptidyl peptidase-4 (DPP4) inhibitor. After 1 h GLP-1 in supernatants was measured and cell lysates taken for qPCR. αLA (12.5 µM) significantly stimulated GLP-1 secretion compared with the control. Phe (6.25-25 mM) and Trp (2.5-10 mM) showed a clear dose response for GLP-1 secretion. The combination of αLA (6.25 µM) and either Phe (12.5 mM) or Trp (5 mM) significantly increased GLP-1 secretion compared with αLA, Phe, or Trp individually. The combination of αLA and Trp upregulated GPR120 expression and potentiated GLP-1 secretion. These nutrient combinations could be used in sustained-delivery formulations to the colon to prolong GLP-1 release for diminishing appetite and preventing obesity.

Role of SIRT-1 as a target for treatment and prevention of Diabetic Nephropathy: A Review

Type-2 diabetes mellitus is a prime factor for the development of Diabetic Nephropathy (DN) that affects the vital organ, namely the kidneys, and further alters the functions of the nephron system. DN is becoming a challenge for scientists worldwide because of its high pervasiveness and complex medication. Various risk factors are involved in the initiation of pathogenic DN, which are associated with different pathways against drug activity. Due to this, DN becomes an unpredictable query for the researchers. SIRT1, a silent information regulator factor 2 related enzyme 1 (SIRT1), is nicotinamide adenine dinucleotide (NAD+) dependent deacetylase that functions as an intracellular regulator of transcriptional activity. An activated version of SIRT-1 improves the diseased metabolic conditions associated with other molecular pathways. SIRT1 attenuates diabetic nephropathy in in vitro and in vivo experimental models of diabetes containing podocytes, mesangial cells, and renal proximal tubular cells. SIRT1 shows nephroprotective effects in DN through deacetylation of transcription factors, i.e., in the disease, like p53, PTP1B, FOXO, RelA, NF- kβ, STAT-3, and PGC-1α/ PPARγ. It has been shown that some natural products like resveratrol and synthetic compounds activate the SIRT1, further involving the cascade pathways to prevent DN. This review will help regarding the effectiveness of SIRT1 as a target in the prevention and treatment of DN.

Role of Circadian Transcription Factor Rev-Erb in Metabolism and Tissue Fibrosis

Circadian rhythms significantly affect metabolism, and their disruption leads to cardiometabolic diseases and fibrosis. The clock repressor Rev-Erb is mainly expressed in the liver, heart, lung, adipose tissue, skeletal muscles, and brain, recognized as a master regulator of metabolism, mitochondrial biogenesis, inflammatory response, and fibrosis. Fibrosis is the response of the body to injuries and chronic inflammation with the accumulation of extracellular matrix in tissues. Activation of myofibroblasts is a key factor in the development of organ fibrosis, initiated by hormones, growth factors, inflammatory cytokines, and mechanical stress. This review summarizes the importance of Rev-Erb in ECM remodeling and tissue fibrosis. In the heart, Rev-Erb activation has been shown to alleviate hypertrophy and increase exercise capacity. In the lung, Rev-Erb agonist reduced pulmonary fibrosis by suppressing fibroblast differentiation. In the liver, Rev-Erb inhibited inflammation and fibrosis by diminishing NF-κB activity. In adipose tissue, Rev- Erb agonists reduced fat mass. In summary, the results of multiple studies in preclinical models demonstrate that Rev-Erb is an attractive target for positively influencing dysregulated metabolism, inflammation, and fibrosis, but more specific tools and studies would be needed to increase the information base for the therapeutic potential of these substances interfering with the molecular clock.

Colonic Delivery of Nutrients for Sustained and Prolonged Release of Gut Peptides: A Novel Strategy for Appetite Management

Obesity is one of the major global threats to human health and risk factors for cardiometabolic diseases and certain cancers. Glucagon-like peptide-1 (GLP-1) plays a major role in appetite and glucose homeostasis and recently the USFDA approved GLP-1 agonists for the treatment of obesity and type 2 diabetes. GLP-1 is secreted from enteroendocrine L-cells in the distal part of the gastrointestinal (GI) tract in response to nutrient ingestion. Endogenously released GLP-1 has a very short half-life of <2 min and most of the nutrients are absorbed before reaching the distal GI tract and colon, which hinders the use of nutritional compounds for appetite regulation. The review article focuses on nutrients that endogenously stimulate GLP-1 and peptide YY (PYY) secretion via their receptors in order to decrease appetite as preventive action. In addition, various delivery technologies such as pH-sensitive, mucoadhesive, time-dependent, and enzyme-sensitive systems for colonic targeting of nutrients delivery are described. Sustained colonic delivery of nutritional compounds could be one of the most promising approaches to prevent obesity and associated metabolic diseases by, e.g., sustained GLP-1 release.

Amelioration of high-fat diet (HFD) + CCl4 induced NASH/NAFLD in CF-1 mice by activation of SIRT-1 using cinnamoyl sulfonamide hydroxamate derivatives: in-silico molecular modelling and in-vivo prediction

Non-alcoholic fatty liver disease (NAFLD) is one of the major hepatic metabolic disorders that occurs because of the accumulation of lipids in hepatocytes in the form of free fatty acids (FFA) and triglycerides (TG) which become non-alcoholic steatohepatitis (NASH). NOTCH-1 receptors act as novel targets for the development of NAFLD/NASH, where overexpression of NOTCH-1 receptor alters the lipid metabolism in hepatocytes leading to NAFLD. SIRT-1 deacetylates the NOTCH-1 receptor and inhibits NAFLD. Hence, computer-aided drug design (CADD) was used to check the SIRT-1 activation ability of cinnamic sulfonyl hydroxamate derivatives (NMJ 1–8), resveratrol, and vorinostat. SIRT-1 (PDB ID: 5BTR) was docked with eight hydroxamate derivatives and vorinostat using Schrödinger software. Based on binding energy obtained (– 26.31 to – 47.34 kcal/mol), vorinostat, NMJ-2, NMJ-3, NMJ-5 were selected for induced-fit docking (IFD) and results were within – 750.70 to – 753.22 kcal/mol. Qikprop tool was used to analyse the pre pharmacokinetic parameters (ADME analysis) of all hydroxamate compounds. As observed in the molecular dynamic (MD) study, NMJ-2, NMJ-3 were showing acceptable results for activation of SIRT-1. Based on these predictions, in-vivo studies were conducted in CF1 mice, where NMJ-3 showed significant (p < 0.05) changes in lipid profile and anti-oxidant parameters (Catalase, SOD, GSH, nitrite, and LPO) and plasma insulin levels. NMJ-3 treatment also reduced inflammation, fibrosis, and necrosis in liver samples.

In silico Study to Evaluate the Antiviral Activity of Novel Structures against 3C-like Protease of Novel Coronavirus (COVID-19) and SARS-CoV

BACKGROUND

Globally, over 4.3 million laboratory confirmed cases of COVID-19 have been reported from over 105 countries. No FDA approved antiviral is available for the treatment of this infection. Zhavoronkov et al., with their generative chemistry pipeline, have generated structures that can be potential novel drug-like inhibitors for COVID-19, provided they are validated. 3C-like protease (3CLP) is a homodimeric cysteine protease that is present in coronaviruses. Interestingly, 3CLP is 96.1% structurally similar between SARS-CoV and SARS-CoV-2.

OBJECTIVE

To evaluate interaction of generated structures with 3CLP of SARS-CoV (RCSB PDB ID: 4MDS).

METHODS

Crystal structure of human SARS-CoV with a non-covalent inhibitor with resolution: 1.598 Å was obtained and molecular docking was performed to evaluate the interaction with generated structures. The MM-GBSA and IFD-SP were performed to narrow down to the structures with better binding energy and IFD score. The ADME analysis was performed on top 5 hits and further MD simulation was employed for top 2 hits.

RESULTS

In XP docking, IFD-SP and molecular dynamic simulation studies, the top 2 hits 32 and 61 showed interaction with key amino acid residue GLU166. Structure 61, also showed interaction with HIS164. These interactions of generated structure 32 and 61, with GLU166 and HIS164, indicate the binding of the selected drug within the close proximity of 3CLP. In the MD simulation, the protein- ligand complex of 4MDS and structure 61 was found to be more stable for 10ns.

CONCLUSION

These identified structures can be further assessed for their antiviral activity to combat SARS-CoV and COVID-19.

Treatment approaches for COVID-19: A critical review

BACKGROUND

Coronavirus disease 2019 (COVID-19) outbreak was declared as an emergency global public health concern on 30 January 2020. This novel coronavirus (SARS-CoV-2) outbreak was first identified in Wuhan city, China; which soon affected around 185 countries and territories all over the world through various transmission mechanisms. Having found no permanent cure to date, this pandemic threatens humanity for its very existence.

OBJECTIVE

In the light of rising menace, this review aims at providing collective and prominent information on the current outbreak covering its origin, structure, transmission, clinical features, potential treatment approaches, and clinical trial details.

METHOD

Literature published in Scopus and PubMed indexed journals were reviewed and clinical trial data was retrieved from the ClinicalTrials.gov database.

RESULTS

Present review puts forth detailed insights on history, epidemiology, structure, genetic makeup, reservoirs, entry mechanisms, reproduction capacity, pathogenesis, routes of transmission, clinical features, diagnostics, the role of chloroquine in treatment, current promising therapies, and vaccination trials.

CONCLUSION

At present, early detection, isolation of infected patients, and supportive care with a few recently USFDA approved alternative medications are being used as per the standard government guidelines. Due to insufficient proof available regarding current therapies to produce therapeutic activity against COVID-19, safety precautions, prevention methods, maintaining hygiene and management therapy with intensive care medicine is the only way to fight this current situation.