Glucagon-like peptide-1 receptor agonists as a possible intervention to delay the onset of type 1 diabetes:A new horizon

Type 1 diabetes(T1D)is a chronic autoimmune condition that destroys insulinproducing beta cells in the pancreas,leading to insulin deficiency and hyperglycemia.The management of T1D primarily focuses on exogenous insulin replacement to control blood glucose levels.However,this approach does not address the underlying autoimmune process or prevent the progressive loss of beta cells.Recent research has explored the potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)as a novel intervention to modify the disease course and delay the onset of T1D.GLP-1RAs are medications initially developed for treating type 2 diabetes.They exert their effects by enhancing glucose-dependent insulin secretion,suppressing glucagon secretion,and slowing gastric emptying.Emerging evidence suggests that GLP-1RAs may also benefit the treatment of newly diagnosed patients with T1D.This article aims to highlight the potential of GLP-1RAs as an intervention to delay the onset of T1D,possibly through their potential immunomodulatory and anti-inflammatory effects and preservation of beta-cells.This article aims to explore the potential of shifting the paradigm of T1D management from reactive insulin replacement to proactive disease modification,which should open new avenues for preventing and treating T1D,improving the quality of life and long-term outcomes for individuals at risk of T1D.

GLP-1, GIP/GLP-1, and GCGR/GLP-1 receptor agonists: Novel therapeutic agents for metabolic dysfunction-associated steatohepatitis

The global prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)is estimated at 32.4%,reflecting its growing clinical significance.MASLD,which includes MASLD and metabolic dysfunction-associated steato-hepatitis(MASH)has been linked to increased metabolic,cardiovascular,and malignant morbidity.Progression into fibrotic stages of MASLD is also strongly associated with liver-related mortality.The past few years have seen a heightened focus on creating innovative therapeutic strategies for MASH management.GLP-1 receptor agonists(RA)have also emerged as a potential treatment option.Studies on GLP-1 agonists,such as liraglutide and semaglutide,have demonstrated efficacy in MASH management,albeit with limited histological improvement of fibrosis.However,recent investigations into GLP-1/GIP RA(tirzepatide)and Glucagon/GLP-1 RA(survodutide)have shown even more encouraging results,with higher rates of MASH resolution and fibrosis improvement.The tolerability of these medications due to their gastrointestinal side effects remains a major concern.Future research should focus on optimizing drug regimens,identifying patients most likely to benefit,and balancing efficacy with tolerability.The evolving landscape of MASH therapeutics suggests a bright future,with the potential for combination therapies to further enhance patient outcomes.

Glucagon-like peptide-1 receptor agonists:Exploring the mechanisms from glycemic control to treatment of multisystemic diseases

This editorial takes a deeper look at the insights provided by Soresi and Giannitrapani,which examined the therapeutic potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)for metabolic dysfunction-associated fatty liver disease.We provide supplementary insights to their research,highlighting the broader systemic implications of GLP-1RAs,synthesizing the current understanding of their mechanisms and the trajectory of research in this field.GLP-1RAs are revolutionizing the treatment of type 2 diabetes mellitus and beyond.Beyond glycemic control,GLP-1RAs demonstrate cardiovascular and renal protective effects,offering potential in managing diabetic kidney disease alongside renin–angiotensin–aldosterone system inhibitors.Their role in bone metabolism hints at benefits for diabetic osteoporosis,while the neuroprotective properties of GLP-1RAs show promise in Alzheimer's disease treatment by modulating neuronal insulin signaling.Additionally,they improve hormonal and metabolic profiles in polycystic ovary syndrome.This editorial highlights the multifaceted mechanisms of GLP-1RAs,emphasizing the need for ongoing research to fully realize their therapeutic potential across a range of multisystemic diseases.

Interplay of gut microbiota,glucagon-like peptide receptor agonists,and nutrition:New frontiers in metabolic dysfunction-associated steatotic liver disease therapy

The gut-liver axis plays a crucial role in the development and progression of metabolic dysfunction-associated steatotic liver disease(MASLD).Key metabolites,including lipopolysaccharides,short-chain fatty acids(SCFAs),bile acids,and beneficial gut bacteria such as Bifidobacterium and Lactobacillus,are pivotal in this process.Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)show promise in managing MASLD by promoting weight loss,enhancing insulin secretion,and improving liver health.They restore gut-liver axis functionality,and their effects are amplified through dietary modifications and gut microbiometargeted therapies.Emerging research highlights the interplay between GLP-1 RAs and gut microbiota,indicating that the gut microbiome significantly influences therapeutic outcomes.Metabolites produced by gut bacteria,can stimulate glucagon-like peptide-1(GLP-1)secretion,further improving metabolic health.Integrating dietary interventions with GLP-1 RA treatment may enhance liver health by modulating the gut microbiota-SCFAs-GLP-1 pathway.Future research is needed to understand personalized effects,with prebiotics and probiotics offering treatment avenues for MASLD.

GLP-1 receptor agonists and myocardial metabolism in atrial fibrillation

Atrial fibrillation(AF)is the most common cardiac arrhythmia.Many medical conditions,including hypertension,diabetes,obesity,sleep apnea,and heart failure(HF),increase the risk for AF.Cardiomyocytes have unique metabolic characteristics to maintain adenosine triphosphate production.Significant changes occur in myocardial metabolism in AF.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)have been used to control blood glucose fluctuations and weight in the treatment of type 2 diabetes mellitus(T2DM)and obesity.GLP-1RAs have also been shown to reduce oxidative stress,inflammation,autonomic nervous system modulation,and mitochondrial function.This article reviews the changes in metabolic characteristics in cardiomyocytes in AF.Although the clinical trial outcomes are unsatisfactory,the findings demonstrate that GLP-1 RAs can improve myocardial metabolism in the presence of various risk factors,lowering the incidence of AF.

Impact of glucagon-like peptide receptor agonists on endoscopy and its preoperative management: Guidelines, challenges, and future directions

Glucagon-like peptide receptor agonists(GLP-1RA)are used to treat type 2 diabetes mellitus and,more recently,have garnered attention for their effect-iveness in promoting weight loss.They have been associated with several gastrointestinal adverse effects,including nausea and vomiting.These side effects are presumed to be due to increased residual gastric contents.Given the potential risk of aspiration and based on limited data,the American Society of Anesthesi-ologists updated the guidelines concerning the preoperative management of patients on GLP-1RA in 2023.They included the duration of mandated cessation of GLP-1RA before sedation and usage of“full stomach”precautions if these medications were not appropriately held before the procedure.This has led to additional challenges,such as extended waiting time,higher costs,and increased risk for patients.In this editorial,we review the current societal guidelines,clinical practice,and future directions regarding the usage of GLP-1RA in patients undergoing an endoscopic procedure.

A Retrospective Analysis of Glucagon-Like Peptide 1 Receptor Agonists in Treating Type 2 Diabetes Mellitus Complicated by Nonalcoholic Fatty Liver Disease

Background: The objective of this study was to compare and analyze the variations in clinical indices before and after treatment of type 2 mellitus (T2DM) combined with nonalcoholic fatty liver disease (NAFLD) that were treated with glucagon-like peptide 1 receptor agonists (GLP-1RAs). Methods: The electronic medical record system was utilized to search for a total of 16 patients with type 2 diabetes complicated by NAFLD who were hospitalized at the First Affiliated Hospital of Yangtze University from October 2022 to April 2023 and treated with GLP-1RA for the first time. The clinical indices were compared before and after 12 weeks of treatment with GLP-1RA. Results: The liver-spleen CT ratio (L/S), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) in all patients treated with GLP-1RA after 12 weeks were significantly different (P 0.05). The patients were categorized into two groups based on the types of GLP-1RAs. The changes in L/S, TC, TG, and LDL-C in the long-acting group after treatment were statistically significant (P Conclusions: GLP-1RAs can improve liver function, regulate lipid metabolism, and reduce the severity of fatty liver in patients with T2DM complicated by NAFLD, which demonstrates the importance of clinical applications.

Development of abscisic acid receptor agonists/antagonists and their application prospect in agriculture:An overview

Abscisic acid(ABA),a plant hormone,is crucial for regulating various physiological and developmental processes in plants,including adaptation to biotic and abiotic stresses.Recent advancements have significantly contributed to our understanding of ABA's biosynthetic pathway,transport,signaling pathway,and metabolism.To overcome the limitations of natural ABA,scientists have developed broad-spectrum and highly active agonists of ABA receptors.However,the practical application of these receptor agonists as agrochemicals still faces several challenges.On the other hand,some ABA antagonists have also been developed to differentiate the functional differences among various receptors more accurately.This can help design ABA agonists that can selectively activate specific physiological responses,thereby eliminating the undesired physiological effects induced by ABA.This paper aims to provide a comprehensive overview of the current ABA receptor agonists and antagonists to assist in developing novel ABA functional analogs with improved efficacy and simpler chemical structures that are suitable for agricultural applications.

Peroxisome proliferator-activated receptor agonists:A new hope towards the management of alcoholic liver disease

In this editorial,we examine a paper by Koizumi et al,on the role of peroxisome proliferator-activated receptor(PPAR)agonists in alcoholic liver disease(ALD).The study determined whether elafibranor protected the intestinal barrier and reduced liver fibrosis in a mouse model of ALD.The study also underlines the role of PPARs in intestinal barrier function and lipid homeostasis,which are both affected by ALD.Effective therapies are necessary for ALD because it is a critical health issue that affects people worldwide.This editorial analyzes the possibility of PPAR agonists as treatments for ALD.As key factors of inflammation and metabolism,PPARs offer multiple methods for managing the complex etiology of ALD.We assess the abilities of PPARα,PPARγ,and PPARβ/δagonists to prevent steatosis,inflammation,and fibrosis due to liver diseases.Recent research carried out in preclinical and clinical settings has shown that PPAR agonists can reduce the severity of liver disease.This editorial discusses the data analyzed and the obstacles,advantages,and mechanisms of action of PPAR agonists for ALD.Further research is needed to understand the efficacy,safety,and mechanisms of PPAR agonists for treating ALD.

Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus

Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus common second-line choice after metformin for treating T2DM.Various considerations can make selecting and switching between different GLP-1 RAs challenging.Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.

Combining GLP-1 receptor agonists and SGLT-2 inhibitors for cardiovascular disease prevention in type 2 diabetes:A systematic review with multiple network meta-regressions

BACKGROUND Glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are associated with significant cardiovascular benefit in type 2 diabetes(T2D).However,GLP-1RA or SGLT-2I alone may not improve some cardiovascular outcomes in patients with prior cardiovascular co-morbidities.AIM To explore whether combining GLP-1RA and SGLT-2I can achieve additional benefit in preventing cardiovascular diseases in T2D.METHODS The systematic review was conducted according to PRISMA recommendations.The protocol was registered on PROSPERO(ID:42022385007).A total of 107049 participants from eligible cardiovascular outcomes trials of GLP-1RA and SGLT-2I were included in network meta-regressions to estimate cardiovascular benefit of the combination treatment.Effect modification of prior myocardial infarction(MI)and heart failure(HF)was also explored to provide clinical insight as to when the INTRODUCTION The macro-and micro-vascular benefits of glucagon-like peptide-1 receptor agonists(GLP-1RA)and sodium-glucose co-transporter-2 inhibitors(SGLT-2I)are independent of their glucose-lowering effects[1].In patients with type 2 diabetes(T2D),the major cardiovascular outcome trials(CVOT)showed that dipeptidyl peptidase-4 inhibitors(DPP-4I)did not improve cardiovascular outcomes[2],whereas cardiovascular benefit of GLP-1RA or SGLT-2I was significant[3,4].Further subgroup analyses indicated that the background cardiovascular risk should be considered when examining the cardiovascular outcomes of these newer glucose-lowering medications.For instance,prevention of major adverse cardiovascular events(MACE)was only seen in those patients with baseline atherosclerotic cardiovascular disease[3,4].Moreover,a series of CVOT conducted in patients with heart failure(HF)have demonstrated that(compared with placebo)SGLT-2I significantly reduced risk of hospitalization for HF or cardiovascular death,irrespective of their history of T2D[5-8].However,similar cardiovascular benefits were not observed in those with myocardial infarction(MI)[9,10].Cardiovascular co-morbidities are not only approximately twice as common but are also associated with dispropor-tionately worse cardiovascular outcomes in patients with T2D,compared to the general population[11].Therefore,it is of clinical importance to investigate whether the combination treatment of GLP-1RA and SGLT-2I could achieve greater cardiovascular benefit,particularly when considering patients with cardiovascular co-morbidities who may not gain sufficient cardiovascular protection from the monotherapies.This systematic review with multiple network meta-regressions was mainly aimed to explore whether combining GLP-1RA and SGLT-2I can provide additional cardiovascular benefit in T2D.Cardiovascular outcomes of these newer antidiabetic medications were also estimated under effect modification of prior cardiovascular diseases.This was to provide clinical insight as to when the combination treatment might be prioritized.

Role of incretins and glucagon receptor agonists in metabolic dysfunction-associated steatotic liver disease:Opportunities and challenges

Metabolic dysfunction-associated steatotic liver disease(MASLD)has become the most common chronic liver disease worldwide,paralleling the rising pandemic of obesity and type 2 diabetes.Due to the growing global health burden and com-plex pathogenesis of MASLD,a multifaceted and innovative therapeutic approach is needed.Incretin receptor agonists,which were initially developed for diabetes management,have emerged as promising candidates for MASLD treatment.This review describes the pathophysiological mechanisms and action sites of three major classes of incretin/glucagon receptor agonists:glucagon-like peptide-1 receptor agonists,glucose-dependent insulinotropic polypeptide receptor agonists,and glucagon receptor agonists.Incretins and glucagon directly or indirectly impact various organs,including the liver,brain,pancreas,gastro-intestinal tract,and adipose tissue.Thus,these agents significantly improve glycemic control and weight management and mitigate MASLD pathogenesis.Importantly,this study provides a summary of clinical trials analyzing the effect-iveness and safety of incretin receptor agonists in MASLD management and provides an in-depth analysis highlighting their beneficial effects on improving liver function,hepatic steatosis,and intrahepatic inflammation.There are emerging challenges associated with the use of these medications in the real world,particularly adverse events,drug-drug interactions,and barriers to access,which are discussed in detail.Additionally,this review highlights the evolving role of incretin receptor agonists in MASLD management and suggests future research directions.

Effects of glucagon-like peptide-1 receptor agonists on non-alcoholic fatty liver disease and inflammation

Glucagon-like peptide1 (GLP-1) is secreted from Langerhans cells in response to oral nutrient intake. Glucagon- like peptide-1 receptor agonists (GLP-1RAs) are a new class of incretin-based anti-diabetic drugs. They function to stimulate insulin secretion while suppressing glucagon secretion. GLP-1-based therapies are now well established in the management of type 2 diabetes mellitus (T2DM), and recent literature has suggested potential applications of these drugs in the treatment of obesity and for protection against cardiovascular and neurological diseases. As we know, along with change in lifestyles, the prevalence of non-alcoholic fatty liver disease (NAFLD) in China is rising more than that of viral hepatitis and alcoholic fatty liver disease, and NAFLD has become the most common chronic liver disease in recent years. Recent studies further suggest that GLP-1RAs can reduce transaminase levels to improve NAFLD by improving blood lipid levels, cutting down the fat content to promote fat redistribution, directly decreasing fatty degeneration of the liver, reducing the degree of liver fibrosis and improving inflammation. This review shows the NAFLD-associated effects of GLP-1RAs in animal models and in patients with T2DM or obesity who are participants in clinical trials. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Glucagon-like peptide-1 receptor agonists in non-alcoholic fatty liver disease: An update

Non-alcoholic fatty liver disease(NAFLD)is the predominant cause of chronic liver disease worldwide.NAFLD progresses in some cases to non-alcoholic steatohepatitis(NASH),which is characterized,in addition to liver fat deposition,by hepatocyte ballooning,inflammation and liver fibrosis,and in some cases may lead to hepatocellular carcinoma.NAFLD prevalence increases along with the rising incidence of type 2 diabetes mellitus(T2DM).Currently,lifestyle interventions and weight loss are used as the major therapeutic strategy in the vast majority of patients with NAFLD.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)are used in the management of T2DM and do not have major side effects like hypoglycemia.In patients with NAFLD,the GLP-1 receptor production is down-regulated.Recently,several animal and human studies have emphasized the role of GLP-1RAs in ameliorating liver fat accumulation,alleviating the inflammatory environment and preventing NAFLD progression to NASH.In this review,we summarize the updated literature data on the beneficial effects of GLP-1RAs in NAFLD/NASH.Finally,as GLP-1RAs seem to be an attractive therapeutic option for T2DM patients with concomitant NAFLD,we discuss whether GLP-1RAs should represent the first line pharmacotherapy for these patients.

Is there a role for glucagon-like peptide-1 receptor agonists in the management of diabetic nephropathy?

Chronic kidney disease constitutes a major microvascular complication of diabetes mellitus.Accumulating data suggest that glucagon-like peptide-1 receptor agonists(GLP-1 RAs)might have a role in the management of diabetic kidney disease(DKD).GLP-1 RAs appear to reduce the incidence of persistent macro-albuminuria in patients with type 2 diabetes mellitus.This beneficial effect appears to be mediated not only by the glucose-lowering action of these agents but also on their blood pressure lowering,anti-inflammatory and antioxidant effects.On the other hand,GLP-1 RAs do not appear to affect the rate of decline of glomerular filtration rate.However,this might be due to the relatively short duration of the trials that evaluated their effects on DKD.Moreover,these trials were not designed nor powered to assess renal outcomes.Given than macrolbuminuria is a strong risk factor for the progression of DKD,it might be expected that GLP-1 RAs will prevent the deterioration in renal function in the long term.Nevertheless,this remains to be shown in appropriately designed randomized controlled trials in patients with DKD.

Review on the Effect of Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors for the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease（NAFLD） is a common liver disease and it represents the hepatic manifestation of metabolic syndrome, which includes type 2 diabetes mellitus（T2DM）, dyslipidemia, central obesity and hypertension. Glucagon-like peptide-1（GLP-1） analogues and dipeptidyl peptidase-4（DPP-4） inhibitors were widely used to treat T2 DM. These agents improve glycemic control, promote weight loss and improve lipid metabolism. Recent studies have demonstrated that the GLP-1 receptor（GLP-1R） is present and functional in human and rat hepatocytes. In this review, we present data from animal researches and human clinical studies that showed GLP-1 analogues and DPP-4 inhibitors can decrease hepatic triglyceride（TG） content and improve hepatic steatosis, although some effects could be a result of improvements in metabolic parameters. Multiple hepatocyte signal transduction pathways and m RNA from key enzymes in fatty acid metabolism appear to be activated by GLP-1 and its analogues. Thus, the data support the need for more rigorous prospective clinical trials to further investigate the potential of incretin therapies to treat patients with NAFLD.

Metabolic and cardiovascular benefits with combination therapy of SGLT-2 inhibitors and GLP-1 receptor agonists in type 2 diabetes

Both GLP-1 receptor agonists(GLP-1RA)and SGLT-2 inhibitors(SGLT-2I)are newer classes of anti-diabetic agents that lower HbA1c moderately and decrease body weight and systolic blood pressure(SBP)modestly.Combination therapy with GLP-1RA plus SGLT-2I have shown a greater reduction in HbA1c,body weight,and SBP compared to either agent alone without any significant increase in hypoglycemia or other side effects.Since several agents from each class of these drugs have shown an improvement in cardiovascular(CV)and renal outcomes in their respective cardiovascular outcome trials(CVOT),combination therapy is theoretically expected to have additional CV and renal benefits.In this comprehensive opinion review,we found HbA1c lowering with GLP-1RA plus SGLT-2I to be less than additive compared to the sum of HbA1c lowering with either agent alone,although body weight lowering was nearly additive and the SBP lowering was more than additive.Our additional meta-analysis of CV outcomes with GLP1RA plus SGLT-2I combination therapy from the pooled data of five CVOT found a similar reduction in three-point major adverse cardiovascular events compared to GLP-1RA or SGLT-2I alone,against placebo.Interestingly,a greater benefit in reduction of heart failure hospitalization with GLP-1RA plus SGLT-2I combination therapy was noted in the pooled meta-analysis of two randomized controlled trials.Future adequately powered trials can confirm whether additional CV or renal benefit is truly exerted by GLP-1RA plus SGLT-2I combination therapy.

Glucagon-like-1 receptor agonists and sodium/glucose cotransporter-2 inhibitors combination—are we exploiting their full potential in a real life setting?

BACKGROUND The sodium/glucose cotransporter-2 inhibitors(SGLT-2i)and glucagon-like-1 receptor agonists(GLP-1RA)are antidiabetic agents effective both in hemoglobin A1c(HbA1c)reduction(with a low risk of hypoglycemia)and cardiovascular event prevention.In patients with type 2 diabetes,the add-on value of combination therapy of GLP-1RA and an SGLT-2i seems promising.AIM To investigate whether the efficacy of GLP-1RA and SGLT-2i combination observed in randomized controlled trials translates into therapeutic benefits in the Croatian population during routine clinical practice and follow-up.METHODS We included 200 type 2 diabetes patients with poor glycemic control and analyzed the effects of treatment intensification with(1)GLP-1RA on top of SGLT-2i,(2)SGLT-2i on top of GLP-1RA compared to(3)simultaneous addition of both agents.The primary study endpoint was the proportion of participants with HbA1c<7.0%and/or 5%bodyweight reduction.Secondary outcomes included changes in fasting plasma glucose(FPG),prandial plasma glucose,lowdensity lipoprotein cholesterol,estimated glomerular filtration rate(eGFR),and cardiovascular(CV)incidents assessment over a follow-up period of 12 mo.RESULTS The majority of patients were over 65-years-old,had diabetes duration for more than 10 years.The initial body mass index was 39.41±5.49 kg/m2 and HbA1c 8.32±1.26%.Around half of the patients in all three groups achieved target HbA1c below 7%.A more pronounced decrease in the HbA1c seen with simultaneous SGLT-2i and GLP-1RA therapy was a result of higher baseline HbA1c and not the effect of initiating combination therapy.The number of patients achieving FPG below 7.0 mmol/L was significantly higher in the SGLT-2i group(P=0.021),and 5%weight loss was dominantly achieved in the simultaneous therapy group(P=0.044).A composite outcome(reduction of HbA1c below 7%(53 mmol/mol)with 5%weight loss)was achieved in 32.3%of total patients included in the study.Only 18.2%of patients attained composite outcome defined as HbA1c below 7%(53 mmol/mol)with 5%weight loss and low-density lipoprotein cholesterol<2.5 mmol/L.There were no significant differences between treatment groups.No differences were observed regarding CV incidents or eGFR according to treatment group over a follow-up period.CONCLUSION Combination therapy with GLP-1RA and SGLT-2i is effective in terms of metabolic control,although it remains to be determined whether simultaneous or sequential intensification is better.

Future directions for using estrogen receptor agonists in the treatment of acute and chronic spinal cord injury

All synthetic and natural estrogen receptor agonists, in- cluding the most potent physiological molecule estrogen or estradiol （E2）, work typically via activation of nuclear estrogen receptor alpha （ERα） and estrogen receptor beta （ERβ）. Both ERα and ERβ modulate the expression of a variety of genes in the cells. Neurons and glial cells express ERa and ERβ. Many studies so far from our and other laboratories have firmly established the mode of actions that ERα and ERβ agonists are very promising anti-inflammatory and neuroprotective agents in the treatment of neurodegenera- rive diseases and injuries including spinal cord injury （SCI） （Chakrabarti et al., 2014a）.

3D-QSAR Studies on 3-Substituted N-Benzhydryl-nortropane Analogs as Nociception Receptor Agonists

The nociceptin receptor（NOP） has been involved in multiple biological functions, including pain, anxiety, cough, substance abuse, cardiovascular control, and immunity. Thus, selective NOP agonists might have clinical potential for the treatment of related diseases. In the present work, three-dimensional quantitative structure-activity relationship（3D-QSAR） studies were performed on a series of 3-substituted N-benzhydryl-nortropane analogs as NOP agonists using comparative molecular field analysis（Co MFA） and comparative molecular similarity indices analysis（CoM SIA） techniques. The statistically significant models were obtained with 54 compounds in training set by ligand-based atom-by-atom matching alignment. The CoM FA model gave cross-validated coefficient（q2） value of 0.530 using 6 components, non-cross-validated（r2） value of 0.921 with estimated F value of 93.668, and standard error of estimate（SEE） of 0.185. The best Co MSIA model resulted in q2 = 0.592, r2 = 0.945, N = 10, SEE = 0.162, and F = 75.654, based on steric, electrostatic, hydrophobic and hydrogen bond acceptor fields. The predictive ability of the Co MFA and CoM SIA models was further validated using a test set of 18 molecules that were not included in the training set, which resulted in predictive correlation coefficients（r2pred） of 0.551 and 0.637, respectively. Moreover, the CoM FA and CoM SIA contour maps identified the features important for exhibiting potent binding affinities on NOP, and can thus serve as a useful guide for the design of potential NOP agonists.