Transcriptome wide functional analysis of HBx expressing human hepatocytes stimulated with endothelial cell cross-talk.

Identification of genes dysregulated during the hepatitis B virus (HBV)-host cell interaction adds to the understanding of underlying molecular mechanisms and aids in discovering effective therapies to improve prognosis in hepatitis B virus (HBV)-infected individuals. Through bioinformatics analyses of transcriptomics data, this study aimed to identify potential genes involved in the cross-talk of human hepatocytes expressing the HBV viral protein HBx with endothelial cells. Transient transfection of HBV viral gene X (HBx) was performed in THLE2 cells using pcDNA3 constructs. Through mRNA Sequencing (RNA Seq) analysis, differentially expressed genes (DEGs) were identified. THLE2 cells transfected with HBx (THLE2x) were further treated with conditioned medium from cultured human umbilical vein derived endothelial cells (HUVEC-CM). Gene Ontology (GO) enrichment analysis revealed that interferon and cytokine signaling pathways were primarily enriched for the downregulated DEGs in THLE2x cells treated with HUVEC-CM. One significant module was selected following protein-protein interaction (PPI) network generation, and thirteen hub genes were identified from the module. The prognostic values of the hub genes were evaluated using Kaplan-Meier (KM) plotter, and three genes (IRF7, IFIT1, and IFITM1) correlated with poor disease specific survival (DSS) in HCC patients with chronic hepatitis. A comparison of the DEGs identified in HUVEC-stimulated THLE2x cells with four publicly available HBV-related HCC microarray datasets revealed that PLAC8 was consistently downregulated in all four HCC datasets as well as in HUVEC-CM treated THLE2x cells. KM plots revealed that PLAC8 correlated with worse relapse free survival and progression free survival in HCC patients with hepatitis B virus infection. This study provided molecular insights which may help develop a deeper understanding of HBV-host stromal cell interaction and open avenues for future research.

Spectrum of Anemia in Indian children with Nephrotic Syndrome: a prospective observational study.

We aimed to estimate the prevalence of anemia in children with nephrotic syndrome (NS), determine its etiology, and correlate severity with disease duration and response to steroids. This was a prospective cohort study carried from 15th July 2019-14th July 2021 at the pediatric nephrology clinic, of a teaching hospital in India. We screened children aged 3 months-18 years with NS for eligibility. We excluded those suffering from chronic kidney disease and, on haematinics. All children underwent investigations for evaluation of nephrotic syndrome and anemia. To define the clinical phenotype of nephrotic syndrome, the patients were classified as infrequent relapsers, frequent relapsers, steroid dependent and steroid resistant NS as per ISPN guidelines. Children were followed up at least for a period of one year to define their response to steroids. A total of 125 children were finally analysed for all treatment outcomes. Of 125, 37 (30%) children presented with the first episode of NS. Remaining 88 were follow up cases of NS. Of 125 children, 41 (33%) were found to be anemic as per the WHO criteria. Iron deficiency anemia was found in 21 (51%) children. Steroid resistance was twice more prevalent in the anemic group compared to the non-anemic group, 7.3% vs 4.8% respectively, however this difference was not statistically significant, p = 0.65. Anemic group had a trend of higher no. of children receiving antihypertensives compared to non-anemics (38 (93%) vs. 67 (80%), p = 0.07. CONCLUSION: Iron deficiency anemia was the commonest cause of anemia and, anemia and need for anti-hypertensives to attain BP control and adequate proteinuria often coexisted in children suffering from nephrotic syndrome. WHAT IS KNOWN: • Anemia is a significant complication in children suffering from nephrotic syndrome. • Cause of anemia in nephrotic syndrome is multifactorial. WHAT IS NEW: • Iron deficiency anemia was the most common cause of anemia in Indian children with nephrotic syndrome. • Anemia and need for anti-hypertensives to attain adequate BP control and proteinuria often coexisted in children with nephrotic syndrome.

Exploration of a library of piperonylic acid-derived hydrazones possessing variable aryl functionalities as potent dual cholinesterase and monoamine oxidase inhibitors.

A library of piperonylic acid-derived hydrazones possessing variable aryl moiety was synthesized and investigated for their multifunctional properties against cholinesterases (ChEs) and monoamine oxidases (MAOs). The in vitro enzymatic assay results revealed that the tested hydrazones have exhibited excellent cholinesterase inhibition profile. Compound 4i, (E)-N'-(2,3-dichlorobenzylidene)benzo[d][1,3]dioxole-5-carbohydrazide showed promising dual inhibitory profile against AChE (0.048 ± 0.007 µM), BChE (0.89 ± 0.018 µM), and MAO-B (0.95 ± 0.12 µM) enzymes. SAR exploration revealed that the truncation of the linker connecting both the aryl binding sites of the semicarbazone scaffold, by one atom, has relatively suppressed the AChE inhibitory potential. Kinetic studies disclosed that the compound 4i reversibly inhibited AChE enzyme in a competitive manner (Ki = 8.0 ± 0.076 nM), while it displayed a non-competitive and reversible inhibition profile against MAO-B (Ki = 9.6 ± 0.021 µM). Moreover, molecular docking studies of synthesized compounds against ChEs and MAOs provided the crucial molecular features that enable their close association and interaction with the target enzymes. All atomistic simulation studies confirmed the stable association of compound 4i within the active sites of AChE and MAO-B. In addition, theoretical ADMET prediction studies demonstrated the acceptable pharmacokinetic profile of the dual inhibitors. In summary, the attempted lead simplification study afforded a potent dual ChE-MAO-B inhibitor compound that merits further investigation.

Indole derivatives targeting colchicine binding site as potential anticancer agents.

Microtubules are appealing as intracellular targets for anticancer activity due to their importance in cell division. Three important binding sites are present on the tubulin protein: taxane, vinca, and colchicine binding sites (CBS). Many USFDA-approved drugs such as paclitaxel, ixabepilone, vinblastine, and combretastatin act by altering the dynamics of the microtubules. Additionally, a large number of compounds have been synthesized by medicinal chemists around the globe that target different tubulin binding sites. Although CBS inhibitors have proved their cytotoxic potential, no CBS-targeting drug had been able to reach the market. Several studies have reported design, synthesis, and biological evaluation of indole derivatives as potential anticancer agents. These compounds have been shown to inhibit cancer cell proliferation, induce apoptosis, and disrupt microtubule formation. Moreover, the binding affinity of these compounds to the CBS has been demonstrated using molecular docking studies and competitive binding assays. The present work has reviewed indole derivatives as potential colchicine-binding site inhibitors. The structure-activity relationship studies have revealed the crucial pharmacophoric features required for the potent and selective binding of indole derivatives to the CBS. The development of these compounds with improved efficacy and reduced toxicity could potentially lead to the development of novel and effective cancer therapies.

Synthesis and evaluation of dual fatty acid amide hydrolase-monoacylglycerol lipase inhibition and antinociceptive activities of 4-methylsulfonylaniline-derived semicarbazones.

Fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) are promising targets for neuropathic pain and other CNS disorders. Based on our previous lead compound SIH 3, we designed and synthesized a series of 4-methylsulfonylphenyl semicarbazones and evaluated for FAAH and MAGL inhibition properties. Most of the compounds showed potency towards both enzymes with leading FAAH selectivity. Compound (Z)-2-(2,6-dichlorobenzylidene)-N-(4-(methylsulfonyl)phenyl)hydrazine-1-carboxamide emerged as the lead inhibitor against both FAAH (IC50 = 11 nM) and MAGL (IC50 = 36 nM). The lead inhibitor inhibited FAAH by non-competitive mode, but showed a mixed-type inhibition against MAGL. Molecular docking study unveiled that the docked ligands bind favorably to the active sites of FAAH and MAGL. The lead inhibitor interacted with FAAH and MAGL via π-π stacking via phenyl ring and hydrogen bonding through sulfonyl oxygen atoms or amide NH. Moreover, the stability of docked complexes was rationalized by molecular simulation studies. PAMPA assay revealed that the lead compound is suitable for blood-brain penetration. The lead compound showed better cell viability in lipopolysaccharide-induced neurotoxicity assay in SH-SY5Y cell lines. Further, in-vivo experiments unveiled that dual inhibitor was safe up to 2000 mg/kg with no hepatotoxicity. The dual FAAH-MAGL inhibitor produced significant anti-nociceptive effect in the CCI model of neuropathic pain without altering locomotion activity. Lastly, the lead compound exhibited promising ex-vivo FAAH/MAGL inhibition activity at the dose of 10 mg/kg and 20 mg/kg. Thus, these findings suggest that the semicarbazone-based lead compound can be a potential template for the development of agents for neuropathic pain.

Synthesis and evaluation of carbamate derivatives as fatty acid amide hydrolase and monoacylglycerol lipase inhibitors.

Fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) are the primary catabolic enzymes for endocannabinoids, anandamide (AEA), and 2-arachidonoyl glycerol. Numerous studies have shown that FAAH and MAGL play an important role in modulating various central nervous system activities; hence, the development of small molecule FAAH/MAGL inhibitors is an active area of research. Several small molecules possessing the carbamate scaffold are documented as potential FAAH/MAGL inhibitors. Here, we designed and synthesized a series of open chain and cyclic carbamates and evaluated their dual FAAH-MAGL inhibition properties. Phenyl [4-(piperidin-1-ylmethyl)phenyl]carbamate (2e) emerged as the most potent MAGL inhibitor (IC50 = 19 nM), benzyl (1H-benzo[d]imidazol-2-yl)carbamate (3h) was the most potent FAAH inhibitor (IC50 = 55 nM), and phenyl (6-fluorobenzo[d]thiazol-2-yl)carbamate (2i) egressed as a nonselective dual FAAH-MAGL inhibitor (FAAH: 82 nM, MAGL: 72 nM). The enzyme kinetics experiments revealed that the compounds inhibit FAAH/MAGL in a covalent-reversible manner, with a mixed binding mode of action. Moreover, the lead compounds were found suitable for blood-brain permeation in the parallel artificial membrane permeation assay. Furthermore, docking simulation experiments suggested that the potency of the lead compounds was governed by hydrogen bonds and hydrophobic interactions with the enzyme active sites. In silico drug-likeness and ADMETox prediction studies provided useful information on the compounds' oral absorption, metabolism, and toxicity profiles. In summary, this study afforded potent multifunctional carbamates with appreciable pharmacokinetic profiles meriting further investigation.

Potential role of p53 deregulation in modulating immune responses in human malignancies: A paradigm to develop immunotherapy.

The crucial role played by the oncogenic expression of TP53, stemming from mutation or amyloid formation, in various human malignancies has been extensively studied over the past two decades. Interestingly, the potential role of TP53 as a crucial player in modulating immune responses has provided new insight into the field of cancer biology. The loss of p53's transcriptional functions and/or the acquisition of tumorigenic properties can efficiently modulate the recruitment and functions of myeloid and lymphoid cells, ultimately leading to the evasion of immune responses in human tumors. Consequently, the oncogenic nature of the tumor suppressor p53 can dynamically alter the function of immune cells, providing support for tumor progression and metastasis. This review comprehensively explores the dual role of p53 as both the guardian of the genome and an oncogenic driver, especially in the context of regulation of autophagy, apoptosis, the tumor microenvironment, immune cells, innate immunity, and adaptive immune responses. Additionally, the focus of this review centers on how p53 status in the immune response can be harnessed for the development of tailored therapeutic strategies and their potential application in immunotherapy against human malignancies.

Lead optimization study on indoline-2,3-dione derivatives as potential fatty acid amide hydrolase inhibitors.

Based on the known isatin-based fatty acid amide hydrolase (FAAH) inhibitor BSS-7, we designed and synthesized two small sets (6-13 and 17-20) of N-1 and C-3 substituted isatin derivatives and evaluated them for their in vitro FAAH inhibition properties. The lead simplification by modification of bulky aryl moiety at N-1 with a flexible allyl group produced a nanomolar (IC50 = 6.7 nM, Ki = 5 nM) inhibitor 11 (Z)-3-((1H-benzo[d]imidazol-2-yl)imino)-1-allylindolin-2-one which exhibited a reversible and competitive FAAH inhibition with 1500 times more potency to BSS-7 (1.49 ± 0.03 µM). The lead compound 11 also showed a high blood-brain permeability and a significant antioxidant profile with no neurotoxicity. Docking results suggested that the inhibitor molecules occupied the active site of FAAH and offered optimal binding interactions. A molecular dynamics simulation study ascertained the stability of the lead inhibitor 11-FAAH complex. In silico ADMET profiling studies unveiled that compound 11 possesses good drug-like properties and merits further evaluation.Communicated by Ramaswamy H. Sarma.

Anti-nociceptive potential of an isatin-derived dual fatty acid amide hydrolase-monoacylglycerol lipase inhibitor.

BACKGROUND: Recently, we have reported an isatin-derived carbohydrazone, 5-chloro-N'-(6-chloro-2-oxoindolin-3-ylidene)-2-hydroxybenzohydrazide (SIH 3) as dual nanomolar FAAH (fatty acid amide hydrolase)-MAGL (monoacylglycerol lipase) inhibitor with good CNS penetration and neuroprotective activity profile. In this study, we further investigated the pharmacological profile of compound SIH 3 in the neuropathic pain model along with acute toxicity and ex vivo studies. METHODS: Chronic constrictive injury (CCI) was used to induce neuropathic pain in male Sprague-Dawley rats and the anti-nociceptive activity of the compound SIH 3 was investigated at 25, 50, and 100 mg/kg ip. Subsequently, locomotor activity was measured by rotarod and actophotometer experiments. The acute oral toxicity of the compound was assessed as per the OECD guidelines 423. RESULTS: Compound SIH 3 showed significant anti-nociceptive activity in the CCI-induced neuropathic pain model without altering the locomotor activity. Furthermore, compound SIH 3 showed an excellent safety profile (up to 2000 mg/kg, po) in the acute oral toxicity study and was also non-hepatotoxic. Further, ex vivo studies revealed that the compound SIH 3 produces a significant antioxidant effect in oxidative stress induced by CCI. CONCLUSION: Our findings suggest that the investigated compound SIH 3 has the potential to be developed as an anti-nociceptive agent.

Benzimidazole-derived carbohydrazones as dual monoamine oxidases and acetylcholinesterase inhibitors: design, synthesis, and evaluation.

A series of novel benzimidazole-derived carbohydrazones was designed, synthesized and evaluated for their dual inhibition potential against monoamine oxidases (MAOs) and acetylcholinesterase (AChE) using multitarget-directed ligand approach (MTDL). The investigated compounds have exhibited moderate to excellent in vitro MAOs/AChE inhibitory activity at micromolar to nanomolar concentrations. Compound 12, 2-(1H-Benzo[d]imidazol-1-yl)-N'-[1-(4-hydroxyphenyl) ethylidene]acetohydrazide has emerged as a lead dual MAO-AChE inhibitor by exhibiting superior multi-target activity profile against MAO-A (IC50 = 0.067 ± 0.018 µM), MAO-B (IC50 = 0.029 ± 0.005 µM) and AChE (IC50 = 1.37 ± 0.026 µM). SAR studies suggest that the site A (hydrophobic ring) and site C (semicarbazone linker) modifications attempted on the semicarbazone-based MTDL resulted in a significant enhancement in the MAO-A/B inhibitory potential and a drastic decrease in the AChE inhibitory activity. Further, molecular docking and dynamics simulation experiments disclosed the possible molecular interactions of inhibitors inside the active site of respective enzymes. Also, computational prediction of drug-likeness and ADME parameters of test compounds revealed their drug-like characteristics.Communicated by Ramaswamy H. Sarma.

Tracing the Anti-cancer Mechanism of Pleurotus osteratus by the Integrative Approach of Network Pharmacology and Experimental Studies.

The present study identified the probable mechanism behind the anti-cancer activity of the hexane fraction of Pleurotus osteratus (HFPO) using network pharmacology and experimental validation. HFPO myco-metabolites targets and targets related to the cancer were mined from the online web server, and overlapping targets were screened. Out of the 74 overlapping targets, 33 targets were identified in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of cancer. Furthermore, the main active myco-metabolites and hub targets were identified by network analysis of the compound-targets network and protein-protein interaction (PPI), respectively. Molecular docking results showed good binding affinity of the hub targets with their respective myco-metabolites. HFPO induced in-vitro anti-cancer activity by affecting the PI3K-AKT-mTOR pathway, besides time-dependent cell cytotoxicity and apoptotic cell body formation. Additionally, tumor volume reduction was observed in HFPO-treated Ehrlich ascites carcinoma (EAC) bearing Swiss albino mice. Overall, HFPO induces anti-cancer potential by modulating the PI3K-AKT-mTOR signaling pathway.

Discovery of Isatin-Based Carbohydrazones as Potential Dual Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase.

Using ligand-based design strategy, a set of isatin-3-carbohydrazones was designed, synthesized and evaluated for dual fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) inhibition properties. Compound 5-chloro-N'-(5-chloro-2-oxoindolin-3-ylidene)-2-hydroxybenzohydrazide (13 b) emerged as a potent MAGL inhibitor with nanomolar activity (IC50 =3.33 nM), while compound 5-chloro-N'-(1-(4-fluorobenzyl)-2-oxoindolin-3-ylidene)-2-hydroxybenzohydrazide (13 j) was the most potent selective FAAH inhibitor (IC50 =37 nM). Compound 5-chloro-N'-(6-chloro-2-oxoindolin-3-ylidene)-2-hydroxybenzohydrazide (13 c) showed dual FAAH-MAGL inhibitory activity with an IC50 of 31 and 29 nM respectively. Enzyme kinetics studies revealed that the isatin-based carbohydrazones are reversible inhibitors for both FAAH and MAGL. Further, blood-brain permeability assay confirmed that the lead compounds (13 b, 13 c, 13 g, 13 m and 13 q) are suitable as CNS candidates. Molecular dynamics simulation studies revealed the putative binding modes and key interactions of lead inhibitors within the enzyme active sites. The lead dual FAAH-MAGL inhibitor 13 c showed significant antioxidant activity and neuroprotection in the cell-based cytotoxicity assay. In summary, the study yielded three potent FAAH/MAGL inhibitor compounds (13 b, 13 c and 13 j) with acceptable pharmacokinetic profile and thus can be considered as promising candidates for treating neurological and mood disorders.

Anticancer Potential of Small-Molecule Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase.

Recently fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) inhibitors have been in the limelight due to their anticancer potential. Both FAAH and MAGL are the endocannabinoid degrading enzymes that hydrolyze several endogenous ligands, mainly anandamide (AEA) and 2-arachidonic glycerol (2-AG), which regulate various pathophysiological conditions in the body such as emotion, cognition, energy balance, pain sensation, neuroinflammation, and cancer cell proliferation. FAAH and MAGL inhibitors block the metabolism of AEA and 2-AG, increase endogenous levels of fatty acid amides, and exert various therapeutic effects including chronic pain, metabolic disorders, psychoses, nausea and vomiting, depression, and anxiety disorders. FAAH and MAGL are primarily neurotherapeutic targets, but their contribution to various types of carcinomas are significant. Inhibitors of these enzymes either alone or as multitarget agents, or with supra-additive effects show the potential effect in ovarian, breast, prostate, and colorectal cancers. Besides highlighting the role of FAAH and MAGL in cancer progression, this review provides an update on the anticancer capabilities of known and newly discovered FAAH and MAGL inhibitors and also provides further directions to develop FAAH and MAGL inhibitors as new candidates for cancer therapy.

Butyrate induced Tregs are capable of migration from the GALT to the pancreas to restore immunological tolerance during type-1 diabetes.

Type-1 diabetes (T1D) is an autoimmune disease caused by progressive loss of insulin-producing beta cells in the pancreas. Butyrate is a commensal microbial-derived metabolite, implicated in intestinal homeostasis and immune regulation. Here, we investigated the mechanism of diabetes remission in non-obese diabetic (NOD) mice following butyrate administration. Sodium butyrate (150 mM) was administered to female NOD mice in drinking water after the onset of hyperglycemia (15-25 weeks age) and at 4 weeks of age (early-intervention group). Butyrate administration reduced the progression of hyperglycemia in diabetic mice and delayed onset of diabetes in the early-intervention group with a reduction in insulitis. Butyrate administration increased regulatory T cells (Tregs) in the colon, mesenteric lymph nodes, Peyer's patches, and its protective effects diminished upon depletion of Tregs. Further, an increase in α4ß7, CCR9, and GPR15 expressing Tregs in the pancreatic lymph nodes (PLN) and pancreas in butyrate-treated mice suggested migration of gut-primed Tregs towards the pancreas. Finally, the adoptive transfer experiments demonstrated that induced Tregs from gut-associated lymphoid tissue can migrate towards the pancreas and PLN and delay the onset of diabetes. Our results thus suggest that early administration of butyrate can restore immunological tolerance during T1D via induction of Tregs with migratory capabilities.

NonScarring Diffuse Hair Loss in Women: a Clinico-Etiological Study from tertiary care center in North-West India.

BACKGROUND: Diffuse hair loss (DHL) is a common problem in adult women and has a major impact on quality of life. Ascertaining the etiological diagnosis is a challenging task in such patients. Satisfactory treatment can only be instituted after ascertaining the cause of hair loss. OBJECTIVE: To study the clinico-epidemiological profile of nonscarring DHL in females and to ascertain its underlying etiological factors. STUDY DESIGN: Of a total of 110 females, who presented with nonscarring DHL to the outpatient dermatology department, 100 qualified for inclusion in the study. A detailed history, clinical examination, and laboratory investigations were performed in all the patients. Statistical analysis was performed on the data collected. RESULTS: Of 100 cases of DHL which were included in the study, commonest was chronic telogen effluvium (CTE) (62%), followed by female pattern hair loss (FPHL) (22%) and acute telogen effluvium (ATE) (16%). Incidence of hair loss was highest in 21-40 years age group. Psychological stress was seen to be a precipitating factor in 18 patients and found most commonly in women belong to CTE group (n-16, 25.8%). Hemoglobin levels ranged from 80 to 142 gm/L (mean: 119 ± 110). Low hemoglobin level (<120 gm/L) was observed in 57% patients. Total serum ferritin <10 ng/mL was seen in 20 patients, vitamin B12 < 211 pg/mL in 76 cases, vitamin D3 < 30 ng/mL in 81 cases. Subclinical hypothyroidism was present in 11% cases. CONCLUSIONS: Nonscarring DHL is a multifactorial condition with highest incidence in 21- to 40-year age group. Serum ferritin, serum vitamin B12, and D3 levels seem to have a contributing role in the pathogenesis of hair loss, and their supplementation may be needed for a faster regrowth of hair in all cases of hair loss irrespective of the pattern.

Scaffold hopping-guided design of some isatin based rigid analogs as fatty acid amide hydrolase inhibitors: Synthesis and evaluation.

Fatty acid amide hydrolase (FAAH) represents a potential therapeutic target for number of peripheral and nervous system related disorders including neuropathic pain and neuroinflammation. A library of N-(2,4-dichlorobenzoyl) isatin Schiff bases 7a-7l and 8a-8c were designed using the contemporary scaffold-hopping approach, synthesized and investigated for their ability to inhibit human FAAH enzyme using fluorescence based Cayman assay kit. The synthesized compounds inhibited FAAH with IC50 values in the range from 1.49 to 12,858 µM. Compound, 3-(1H-benzoimidazol-2-ylimino)-1-(2,4-dichlorobenzoyl)indolin-2-one (8c) showed strong inhibition against FAAH with IC50 of 1.49 ± 0.03 µM. SAR studies revealed various structural aspects important for the potency of these analogs. In particular, our findings suggested the requirement of hydrophobic aryl/heteroaryl moiety at C-3 position of isatin for optimum rigidity and steric hindrance to the scaffold. Additionally, molecular docking studies supported the experimental results revealing that compound 8c well-occupied the enzymatic cleft with optimal binding orientation and interactions within the active site of FAAH which resulted in reduced susceptibility of compound to nucleophilic attack and prevented it from leaving the active site, thereby increasing the inhibition. Also, compound 8c presented potent antidepressant and anxiolytic properties without any neurotoxicity. In silico molecular properties and ADMET descriptors calculations related the lead FAAH inhibitor 8c presented the satisfactory drug-like characteristics and ADMET properties and thus considered for further optimization. To the best of our knowledge this is the first report on the FAAH inhibitory properties of isatin-based analogs, revealing that both indoline skeleton and heteroaryl substitution at C-3 can modulate the activity of FAAH enzyme. In conclusion, the present study provided a better understanding of the molecular fragments requisite for maintaining and/or improving FAAH inhibition activity.