Discovering phenoxy acetohydrazide derivatives as urease inhibitors and molecular docking studies

Helicobacter pylori causes severe stomach disorders and the use of enzyme inhibitors for treatment is one of the possible therapies. The great biological potential of imine analogs as urease inhibitors has been the focus of researchers in past years. In this regard, we have synthesized twenty-one derivatives of dichlorophenyl hydrazide. These compounds were characterized by different spectroscopic techniques i.e. NMR and HREI-MS. Compounds 2 and 10 were found to be the most active in the series. Structure-activity relationship has been established for all compounds based on different substituents attached to the phenyl ring that play a vital role in enzyme inhibition. From the structure-activity relationship, it has been observed that these analogs showed excellent potential for urease and can be an alternate therapy in the future. The molecular docking study was performed to further explore the binding interactions of synthesized analogs with enzyme active sites.Communicated by Ramaswamy H. Sarma.

Synthesis of indole derivatives as Alzheimer inhibitors and their molecular docking study

Acetylcholinesterase prevails in the healthy brain, with butyrylcholinesterase reflected to play a minor role in regulating brain acetylcholine (ACh) levels. However, BuChE activity gradually increases in patients with (AD), while AChE activity remains unaffected or decays. Both enzymes therefore represent legitimate therapeutic targets for ameliorating the cholinergic deficit considered to be responsible for the declines in cognitive, behavioural, and global functioning characteristic of AD. Current study described the synthesis of indole-based sulfonamide derivatives (1-23) and their biological activity. Synthesis of these scaffolds were achieved by mixing chloro-substituted indole bearing amine group with various substituted benzene sulfonyl chloride in pyridine, under refluxed condition to obtained desired products. All products were then evaluated for AchE and BuchE inhibitory potential compare with positive Donepezil as standard drug for both AchE and BchE having IC50 = 0.016 ± 0.12 and 0.30 ± 0.010 μM respectively. In this regard analog 9 was found potent having IC50 value 0.15 ± 0.050 μM and 0.20 ± 0.10 for both AchE and BuChE respectively. All other derivatives also found with better potential. All compounds were characterized by various techniques such as 1H, 13C-NMR and HREI-MS. In addition, biological activity was maintained to explore the bioactive nature of scaffolds and their protein-ligand interaction (PLI) was checked through molecular docking study.Communicated by Ramaswamy H. Sarma.

Synthesis of thiazole-based-thiourea analogs: as anticancer, antiglycation and antioxidant agents, structure activity relationship analysis and docking study

This work reports the convenient approach for the synthesis of thiazole based thiourea derivatives (1-21) from 2-bromo-1-(4-fluorophenyl)thiazole-1-one and phenyl isothiocyanates. The scope and diversity were achieved from readily available phenyl isothiocyanates. This protocol involves an oxidative C-S bond formation. Moreover, hybrid thiazole based thiourea scaffolds (1-21) according to literature known protocol were screened in vitro for anticancer Potential against breast cancer, antiglycation and antioxidant inhibitory profile. All newly developed scaffolds were showed moderate to good inhibitory potentials ranging from 0.10 ± 0.01 µM to 11.40 ± 0.20 µM, 64.20 ± 0.40 µM to 385.10 ± 1.70 µM and 8.90 ± 0.20 µM to 39.20 ± 0.50 µM against anticancer, antiglycation and antioxidant respectively. Among the series, compounds 12 (IC50 = 0.10 ± 0.01 µM), 10 (IC50 = 64.20 ± 0.40 µM) and 12 (IC50 = 8.90 ± 0.20 µM) with flouro substitution at phenyl ring of thiourea were identified to be the most potent among the series having excellent anticancer, antiglycation and antioxidant potential. The structure of all the newly synthetics scaffolds were confirmed by using different types of spectroscopic techniques such as HREI-MS, 1H- and 13C-NMR spectroscopy. To find structure-activity relationship, molecular docking studies were carried out to understand the binding mode of active inhibitors with active site of enzymes and results supported the experimental data.Communicated by Ramaswamy H. Sarma.

Varied Composition and Underlying Mechanisms of Gut Microbiome in Neuroinflammation

The human gut microbiome has been implicated in a host of bodily functions and their regulation, including brain development and cognition. Neuroinflammation is a relatively newer piece of the puzzle and is implicated in the pathogenesis of many neurological disorders. The microbiome of the gut may alter the inflammatory signaling inside the brain through the secretion of short-chain fatty acids, controlling the availability of amino acid tryptophan and altering vagal activation. Studies in Korea and elsewhere highlight a strong link between microbiome dynamics and neurocognitive states, including personality. For these reasons, re-establishing microbial flora of the gut looks critical for keeping neuroinflammation from putting the whole system aflame through probiotics and allotransplantation of the fecal microbiome. However, the numerosity of the microbiome remains a challenge. For this purpose, it is suggested that wherever possible, a fecal microbial auto-transplant may prove more effective. This review summarizes the current knowledge about the role of the microbiome in neuroinflammation and the various mechanism involved in this process. As an example, we have also discussed the autism spectrum disorder and the implication of neuroinflammation and microbiome in its pathogenesis.

Fabrication and Assessment of Diosgenin Encapsulated Stearic Acid Solid Lipid Nanoparticles for Its Anticancer and Antidepressant Effects Using in vitro and in vivo Models

Inflammatory cascade plays a pivotal role in the onset and progression of major depressive disorder (MDD) and glioblastoma multiforme (GBM). Therefore, questing natural compounds with anti-inflammatory activity such as diosgenin can act as a double-edged sword targeting cancer and cancer-induced inflammation simultaneously. The blood–brain barrier limits the therapeutic efficiency of the drugs against intracranial pathologies including depression and brain cancers. Encapsulating a drug molecule in lipid nanoparticles can overcome this obstacle. The current study has thus investigated the anticancer and antidepressant effect of Tween 80 (P80) coated stearic acid solid lipid nanoparticles (SLNPs) encapsulating the diosgenin. Physio-chemical characterizations of SLNPs were performed to assess their stability, monodispersity, and entrapment efficiency. In vitro cytotoxic analysis of naked and drug encapsulated SLNPs on U-87 cell line indicated diosgenin IC₅₀ value to be 194.4 μM, while diosgenin encapsulation in nanoparticles slightly decreases the toxicity. Antidepressant effects of encapsulated and non-encapsulated diosgenin were comprehensively evaluated in the concanavalin-A–induced sickness behavior mouse model. Behavior test results indicate that diosgenin and diosgenin encapsulated nanoparticles significantly alleviated anxiety-like and depressive behavior. Diosgenin incorporated SLNPs also improved grooming behavior and social interaction as well as showed normal levels of neutrophils and leukocytes with no toxicity indication. In conclusion, diosgenin and diosgenin encapsulated solid lipid nanoparticles proved successful in decreasing in vitro cancer cell proliferation and improving sickness behavioral phenotype and thus merit further exploration.

Therapeutic effect of Thymoquinone on behavioural response to UCMS and neuroinflammation in hippocampus and amygdala in BALB/c mice model

RATIONALE

Major depressive disorder is the leading cause of disability worldwide. The corticolimbic system plays a critical role in the emotional and cognitive aspects of major depressive disorder. Owing to the unsatisfactory efficacy of conventional antidepressants, there is a need to explore novel therapies.

OBJECTIVES

The current study aimed to explore the antidepressant potential of thymoquinone, a natural compound with anti-inflammatory activity, and propose its underlying mechanism of action in the unpredictable chronic mild stress (UCMS) mouse model.

METHODS

Coat state, forced swim test, elevated plus maze test, novelty suppressed feeding test and social interaction test were performed to quantify the behavioural shift induced by UCMS and the effect of thymoquinone and fluoxetine treatment. In addition, messenger RNA (mRNA) expression levels of inflammatory cytokines (IL-1β, IL-6 and TNF-α) and BDNF and NeuN were analysed by a quantitative real-time polymerase chain reaction in the hippocampus and amygdala of experimental and control groups.

RESULTS

UCMS significantly deteriorated coat state. Thymoquinone reinstated the resignation behaviour and latency to feed affected by UCMS. UCMS induced an increase in inflammatory cytokines (IL-1β, IL-6 and TNF-α) in the hippocampus and amygdala, which was decreased by thymoquinone. UCMS caused an increase in BDNF and NeuN mRNA levels in the amygdala while a decrease in the hippocampus. This opposite effect on BDNF was also compensated by thymoquinone; however, thymoquinone did not significantly change Ki67 and NeuN mRNA levels in the hippocampus.

CONCLUSIONS

Thymoquinone restored the behavioural changes induced by UCMS. In addition, the antidepressant effect of thymoquinone is in line with changes in inflammatory parameters and changes in BDNF in the hippocampus and amygdala.

Exploring indole-based-thiadiazole derivatives as potent acetylcholinesterase and butyrylcholinesterase enzyme inhibitors

Indole based thiadiazole derivatives (1-18) were synthesized and evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition. The IC₅₀ values of the synthesized analogues ranging between 0.17 ± 0.05 to 33.10 ± 0.6 μM against (AChE) and 0.30 ± 0.1 to 37.60 ± 0.6 μM against (BChE) enzymes. Among the series compounds 8 (IC₅₀ = 0.17 ± 0.05 μM) (IC₅₀ = 0.30 ± 0.1 μM), 9 (IC₅₀ = 0.30 ± 0.05 μM) (IC₅₀ = 0.60 ± 0.05 μM) and 10 (IC₅₀ = 1.30 ± 0.1 μM) (IC₅₀ = 2.60 ± 0.1) were found to be the most potent analogues bearing para, ortho, and meta-fluoro substitutions on phenyl ring attached to thiadiazole. In addition, all the synthesized scaffolds were characterized by using ¹H NMR, ¹³C NMR spectroscopy, and high-resolution Mass Spectrometry (HR-MS). To apprehend the binding mode of interaction of the most potent synthesized derivatives, a molecular docking study was performed.

Synthesis, in vitro antiurease, in vivo antinematodal activity of quinoline analogs and their in-silico study

Synthesis of quinoline analogs and their urease inhibitory activities with reference to the standard drug, thiourea (IC₅₀ = 21.86 ± 0.40 µM) are presented in this study. The inhibitory activity range is (IC₅₀ = 0.60 ± 0.01 to 24.10 ± 0.70 µM) which displayed that it is most potent class of urease inhibitor. Analog 1-9, and 11-13 emerged with many times greater antiurease potential than thiourea, in which analog 1, 2, 3, 4, 8, 9, and 11 (IC₅₀ = 3.50 ± 0.10, 7.20 ± 0.20, 1.30 ± 0.10, 2.30 ± 0.10, 0.60 ± 0.01, 1.05 ± 0.10 and 2.60 ± 0.10 µM respectively) were appeared the most potent ones among the series. In this context, most potent analogs such as 1, 3, 4, 8, and 9 were further subjected for their in vitro antinematodal study against C. elegans to examine its cytotoxicity under positive control of standard drug, Levamisole. Consequently, the cytotoxicity profile displayed that analogs 3, 8, and 9 were found with minimum cytotoxic outline at higher concentration (500 µg/mL). All analogs were characterized through ¹H NMR, ¹³C NMR and HR-EIMS. The protein-ligand binding interaction for most potent analogs was confirmed via molecular docking study.

Synthesis of new urease enzyme inhibitors as antiulcer drug and computational study

In search of potent urease inhibitor indole analogues (1-22) were synthesized and evaluated for their urease inhibitory potential. All analogues (1-22) showed a variable degree of inhibitory interaction potential having IC₅₀ value ranging between 0.60 ± 0.05 to 30.90 ± 0.90 µM when compared with standard thiourea having IC₅₀ value 21.86 ± 0.90 µM. Among the synthesized analogues, the compounds 1, 2, 3, 5, 6, 8, 12, 14, 18, 20 and 22 having IC₅₀ value 3.10 ± 0.10, 1.20 ± 0.10, 4.60 ± 0.10, 0.60 ± 0.05, 5.30 ± 0.20, 2.50 ± 0.10, 7.50 ± 0.20, 3.90 ± 0.10, 3.90 ± 0.10, 2.30 ± 0.05 and 0.90 ± 0.05 µM respectively were found many fold better than the standard thiourea. All other analogues showed better urease interaction inhibition. Structure activity relationship (SAR) has been established for all analogues containing different substituents on the phenyl ring. To understand the binding interaction of most active analogues with enzyme active site docking study were performed.Communicated by Ramaswamy H. Sarma.

Expiry of a completely splenectomised calf in post-operative period due to mixed piroplasm infection: a case report

Bovine babesiosis is an infectious protozoan disease and causes significant economic losses in terms of production loss and mortality. The genus Babesia belongs to the family Babesiidae order piroplasmida and is transmitted by ticks globally. The signs of disease are particularly prominent in old or immuno-compromised animals. The spleen plays a vital role in defence against hemoparasites like Babesia. A young cross-bred cow calf of about 3 months of age was splenectomised to propagate Babesia in vivo experimentally. Prior to splenectomy, the calf was examined through microscopy and PCR analysis and was found negative for any kind of piroplasms including Babesia. The calf was completely splenectomised, but the calf was naturally infected during its postoperative period. The calf expired after naturally acquiring Babesia bigemina and Theileria annulata during the 11 th day of postoperative period owing to increased parasitaemia, exhibiting typical mixed parasitic infection stigmata e.g. reddish urine, elevated temperature up to 41.38°C. This study concluded that complete splenectomy along with dexamethasone administration in the postop period caused exceptional increase in parasitaemia. This parasitaemia couldn't be countered by any symptomatic treatment because of the absence of spleen and greatly reduced immunity of the animal.

Evaluation and docking of indole sulfonamide as a potent inhibitor of α-glucosidase enzyme in streptozotocin -induced diabetic albino wistar rats

We have synthesized new hybrid class of indole bearing sulfonamide scaffolds (1-17) as α-glucosidase inhibitors. All scaffolds were found to be active except scaffold 17 and exhibited IC₅₀ values ranging from 1.60 to 51.20 µM in comparison with standard acarbose (IC₅₀ = 42.45 µM). Among the synthesized hybrid class scaffolds 16 was the most potent analogue with IC₅₀ value 1.60 μM, showing many folds better potency as compared to standard acarbose. Whereas, synthesized scaffolds 1-15 showed good α-glucosidase inhibitory potential. Based on α-glucosidase inhibitory effect, Scaffold 16 was chosen due to highest activity in vitro for further evaluation of antidiabetic activity in Streptozotocin induced diabetic rats. The Scaffold 16 exhibited significant antidiabetic activity. All analogues were characterized through ¹H, ¹³CNMR and HR MS. Structure-activity relationship of synthesized analogues was established and confirmed through molecular docking study.

Synthesis of indole-based-thiadiazole derivatives as a potent inhibitor of α-glucosidase enzyme along with in silico study

A series of nineteen (1-19) indole-based-thiadiazole derivatives were synthesized, characterized by ¹HNMR, ¹³C NMR, MS, and screened for α-glucosidase inhibition. All analogs showed varied α-glucosidase inhibitory potential with IC₅₀ value ranged between 0.95 ± 0.05 to 13.60 ± 0.30 µM, when compared with the standard acarbose (IC₅₀ = 1.70 ± 0.10). Analogs 17, 2, 1, 9, 7, 3, 15, 10, 16, and 14 with IC₅₀ values 0.95 ± 0.05, 1.10 ± 0.10, 1.30 ± 0.10, 1.60 ± 0.10, 2.30 ± 0.10, 2.30 ± 0.10, 2.80 ± 0.10, 4.10 ± 0.20 and 4.80 ± 0.20 µM respectively showed highest α-glucosidase inhibition. All other analogs also exhibit excellent inhibitory potential. Structure activity relationships have been established for all compounds primarily based on substitution pattern on the phenyl ring. Through molecular docking study, binding interactions of the most active compounds were confirmed. We further studied the kinetics study of analogs 1, 2, 9 and 17 and found that they are Non-competitive inhibitors.

Functional connectivity underpinnings of electroconvulsive therapy-induced memory impairments in patients with depression

Electroconvulsive therapy (ECT) is an effective treatment for severe medication-resistant depression. However, ECT frequently results in episodic memory impairments, causing many patients to discontinue treatment. The objective of this study was to explore the functional connectivity underpinnings of ECT-induced episodic memory impairments. We investigated verbal episodic memory and intrinsic functional connectivity in 24 patients with depression (13F, 11M) before and after ECT, and 1 month after treatment. We used a novel individual-oriented approach to examine functional connectivity, and trained a linear support vector regression model to estimate verbal memory performance based on connectivity. The model identified a set of brain connections that can predict baseline verbal memory performance (r = 0.535, p = 0.026). Importantly, we found a nonoverlapping set of brain connections whose changes after ECT can track patients' verbal memory impairments (r = 0.613, p = 0.008). These connections mainly involve the frontoparietal control, default mode, and hippocampal networks, suggesting that ECT affects broad functional networks that are involved in memory performance. In contrast, functional connectivity defined using traditional group-level analyses was unable to estimate either baseline memory performance or post-ECT verbal memory impairments. A parallel analysis using the same strategy did not identify a connectivity marker for overall mood improvement, suggesting that functional connectivity changes related to depressive symptoms may be highly heterogenous. Our findings shed light on the mechanism through which ECT impairs episodic memory, and additionally underline the importance of accounting for interindividual variability in the investigation of functional brain organization in patients with depression.

Thymoquinone harbors protection against Concanavalin A-induced behavior deficit in BALB/c mice model

Global health estimates indicated approximately 322 million people living with depression. Rising cost of depressive illness treatment and non-responsiveness to existing therapies demand continued research to explore new and more potent therapies. Exploring the potential of natural compounds for their potent antidepressant potentials is becoming topic of interest for scientists. Anti-inflammatory activity of thymoquinone, the active ingredient of Nigella sativa, has been well documented. Current study tested thymoquinone for its antidepressant effect in a Concanavalin A (Con A)-induced depressive-like behavior in BALB/c mice. Thymoquinone successfully protected against Con A-induced behavioral despair and anxiety-like behavior. Reduced grooming behavior as a function of Con A treatment, was also reinstated. Underlying mechanism responsible for antidepressant activity of thymoquinone was analyzed by molecular docking. Thymoquinone interacts in halogen-binding pocket (HBP) of serotonin reuptake transporter indicating its potential as serotonin reuptake inhibitor. Results of current study anticipate thymoquinone as a potential antidepressant drug candidate. PRACTICAL APPLICATIONS: Black seeds of Nigella sativa are consumed with traditional and religious reference since centuries. Thymoquinone, active, and abundant component of Nigella sativa, has shown positive effects in multiple studies against arthritis, asthma, hepatic injury, neurodegeneration, and cancer owing to its immunomodulatory and anti-inflammatory attributes. Considering inflammation as one of central components involved in pathophysiology of major depressive disorder, thymoquinone has been evaluated in current study for its antidepressant potential. Positive results of current study propose thymoquinone as an affordable, natural antidepressant drug candidate with better safety profile than currently available antidepressant regimes. Thymoquinone might provide benefits against inflammation-related sickness behavior that is associated with poorer outcome of clinical depression, thus, paving the way for effective drug development against treatment-resistant depression.

Synthesis, in vitro urease inhibitory potential and molecular docking study of benzofuran-based-thiazoldinone analogues

In continuation of our work on enzyme inhibition, the benzofuran-based-thiazoldinone analogues (1-14) were synthesized, characterized by HREI-MS, 1H and 13CNMR and evaluated for urease inhibition. Compounds 1-14 exhibited a varying degree of urease inhibitory activity with IC50 values between 1.2 ± 0.01 to 23.50 ± 0.70 µM when compared with standard drug thiourea having IC50 value 21.40 ± 0.21 µM. Compound 1, 3, 5 and 8 showed significant inhibitory effects with IC50 values 1.2 ± 0.01, 2.20 ± 0.01, 1.40 ± 0.01 and 2.90 ± 0.01 µM respectively, better than the rest of the series. A structure activity relationship (SAR) of this series has been established based on electronic effects and position of different substituents present on phenyl ring. Molecular docking studies were performed to understand the binding interaction of the compounds.

Research Productivity in the Health Sciences in Saudi Arabia: 2008-2017

The purpose of this study was to analyze the published research on health sciences carried out by researchers in Saudi Arabia in the last decade by assessing bibliometric output. Data for 2008 to 2017 was retrieved from Scopus. During this period, there was significant growth, from 1332 publications in 2008 to 5529 in 2017, with an average annual growth rate of 14.1%. King Saud University was the most productive institution. Most of the published research was done in collaboration with Egypt. The subject area of medicine was predominant with the main publication source being the Saudi Medical Journal, Life Science Journal, the Acta Zhengzhou University Oversea Version, and the Annals of Saudi Medicine, primarily in the form of original research articles. The growing trend in publications is a sign of the increasing quality of education and more research and development activities, which are made possible by a sufficient budget allocation to these activities during the last decade.

Exposure to early life adversity alters the future behavioral response to a stressful challenge in BALB/C mice

Depression is considered as a maladaptive response to stress in adult life. Exposure to stress in early childhood is recognized as a risk factor for being unable to adapt to environmental changes in adult life. Early life stress (ELS) has been modelled in animals to help understand the behavioral outcome of the adversity. Periodic maternal separation (MS) in rodents for the first two weeks of life is one such model. We used MS as a form of ELS in Balb/c mice to study its effect on a stressful challenge encountered in adult life. According to our results, exposure to MS predisposed mice to an altered behavioral response. However, this response was not worsened by exposure to restraint stress (RS) experienced in early adult life. This controversy may be attributed to methodological and biological variations among animals as well as humans.

Synthesis, anti-leishmanial and molecular docking study of bis-indole derivatives

We have synthesized new series of bisindole analogs (1–27), characterized by ¹HNMR and HR-EI-MS and evaluated for their anti-leishmanial potential. All compounds showed outstanding inhibitory potential with IC₅₀ values ranging from 0.7 ± 0.01 to 13.30 ± 0.50 µM respectively when compared with standard pentamidine with IC₅₀ value of 7.20 ± 0.20 µM. All analogs showed greater potential than standard except 10, 19 and 23 when compared with standard. Structure activity relationship has been also established for all compounds. Molecular docking studies were carried out to understand the binding interaction of active molecules.

Synthesis of Thymidine Phosphorylase Inhibitor Based on Quinoxaline Derivatives and Their Molecular Docking Study

We have synthesized quinoxaline analogs (1⁻25), characterized by ¹H-NMR and HREI-MS and evaluated for thymidine phosphorylase inhibition. Among the series, nineteen analogs showed better inhibition when compared with the standard inhibitor 7-Deazaxanthine (IC₅₀ = 38.68 ± 4.42 µM). The most potent compound among the series is analog 25 with IC₅₀ value 3.20 ± 0.10 µM. Sixteen analogs 1, 2, 3, 4, 5, 6, 7, 12, 13, 14, 15, 16, 17, 18, 21 and 24 showed outstanding inhibition which is many folds better than the standard 7-Deazaxanthine. Two analogs 8 and 9 showed moderate inhibition. A structure-activity relationship has been established mainly based upon the substitution pattern on the phenyl ring. The binding interactions of the active compounds were confirmed through molecular docking studies.

Synthesis, Molecular Docking and β-Glucuronidase Inhibitory Potential of Indole Base Oxadiazole Derivatives

β-glucuronidase is a lysosomal glycosidase enzyme which catalyzes the extracellular matrix of cancer and normal cells and the glycosaminoglycans of the cell membrane, which is important for cancer cell proliferation, invasion, and metastasis. Liver cancer, colon carcinoma, and neoplasm bladder are triggered by the increase of the level of β-glucuronidase activity. The most valuable structures are indole and oxadiazole which has gain immense attention because of its pharmacological behavior and display many biological properties. Twenty-two (1⁻22) analogs of indole based oxadiazole were synthesized and screened for their inhibitory potential against β-glucuronidase. Majority of the compounds showed potent inhibitory potential with IC₅₀ values ranging between 0.9 ± 0.01 to 46.4 ± 0.9 µM, under positive control of standard drug d-saccharic acid 1,4 lactone (IC₅₀ = 48.1 ± 1.2 µM). Structural activity relationship (SAR) has been established for all synthesized compounds. To shed light on molecular interactions between the synthesized compounds and β-glucuronidase, 1, 4, and 6 compounds were docked into the active binding site of β-glucuronidase. The obtained results showed that this binding is thermodynamically favorable and β-glucuronidase inhibition of the selected compounds increases with the number of hydrogen bonding established in selected compound-β-glucuronidase complexes.

A P2X7 receptor antagonist reverses behavioural alterations, microglial activation and neuroendocrine dysregulation in an unpredictable chronic mild stress (UCMS) model of depression in mice

A polymorphism in the P2RX7 gene that encodes for the P2X7 ionotropic ATP-gated receptor (P2X7R) protein has been shown to be associated with an increased risk for developing depressive illnesses. However, the role of P2X7R in depression is still unclear. To better understand the role of P2X7R and its subsequent impact on microglial activation, we compared the effect of the P2X7R antagonist Brilliant Blue G (BBG) with that of fluoxetine in an unpredictable chronic mild stress (UCMS) model of depression in mice. Our results indicate that BBG (50 mg/kg body weight in 0.9% NaCl, 10 ml/kg/day) successfully reversed the degradation of coat states and nest-building scores induced by exposure to UCMS, similar to the conventional antidepressant fluoxetine (15 mg/kg body weight in 0.9% NaCl, 10 ml/kg/day). BBG also reversed the UCMS-induced microglial activation in cortical and hippocampal regions and the basal nuclei of mouse brains and corrected the UCMS-induced hypothalamo-pituitary-adrenal (HPA) axis dysregulation. In contrast to fluoxetine, however, BBG treatment did not increase the density of doublecortin-positive cells in the dentate gyrus, indicating that BBG had no impact on hippocampal neurogenesis. These results suggest that P2X7R is involved in recovery from depressive-like states caused by exposure to UCMS in a mechanism that involves restoration of the HPA axis but not hippocampal neurogenesis. These results add to the evidence that P2X7R antagonist agents may have potential value in the pharmacological management of depression.

Synthesis, SAR elucidations and molecular docking study of newly designed isatin based oxadiazole analogs as potent inhibitors of thymidine phosphorylase

Thymidine phosphorylase is an enzyme involved in pyrimidine salvage pathway that is identical to platelet-derived endothelial cell growth factor (PD-ECGF) and gliostatin. It is enormously up regulated in a variety of solid tumors. Furthermore, surpassing of TP level protects tumor cells from apoptosis and helps cell survival. Thus TP is identified as a prime target for developing novel anticancer therapies. A new class of exceptionally potent isatin based oxadiazole (1-30) has been synthesized and evaluated for thymidine phosphorylase inhibitory potential. All analogs showed potent thymidine phosphorylase inhibition when compared with standard 7-Deazaxanthine, 7DX (IC₅₀ = 38.68 ± 1.12 µM). Molecular docking study was performed in order to determine the binding interaction of these newly synthesized compounds, which revealed that these synthesized compounds established stronger hydrogen bonding network with active site of residues as compare to the standard compound 7DX.

Nanomedicine and cancer immunotherapy: focus on indoleamine 2,3-dioxygenase inhibitors

Nanomedicine application in cancer immunotherapy is currently one of the most challenging areas in cancer therapeutic intervention. Innovative solutions have been provided by nanotechnology to deliver cytotoxic agents to the cancer cells partially affecting the healthy cells of the body during the process. Nanoparticle-based drug delivery is an emerging approach to stimulate the immune responses against cancer. The inhibition of indoleamine 2,3-dioxygenase (IDO) is a pivotal area of research in cancer immunotherapy. IDO is a heme-containing immunosuppressive enzyme, which is responsible for the degradation of tryptophan while increasing the concentration of kynurenine metabolites. Various preclinical studies showed that IDO inhibition in certain diseases may result in significant therapeutic effects. Here, we provide a review of the natural and synthetic inhibitors of IDO. These inhibitors are classified according to their source, inhibitory concentrations, the chemical structure, and the mechanism of action. Tumor-targeted chemotherapy is an advanced technique and has more advantages as compared to the conventional chemotherapy. Search for more efficient and less toxic nanoparticles in conjunction with compounds to inhibit IDO is still an area of interest for several research groups worldwide, especially revealing to be an extensive and a promising area in cancer therapeutic innovations.

Role of inflammatory cytokines in depression: Focus on interleukin-1β

According to the World Health Organization, major depression will become the leading cause of disability worldwide by the year 2030. Despite extensive research into the mechanisms underlying this disease, the rate, prevalence and disease burden has been on the rise, particularly in the industrialized world. Epidemiological studies have shown biological and biochemical differences in disease characteristics and treatment responses in different age groups. Notable differences have been observed in the clinical presentation, co-prevalence with other diseases, interaction with the immune system and even in the outcome. Thus, there is an increased interest in characterizing these differences, particularly in terms of contribution of different factors, including age, cytokines and immunotherapy. Research into the possible mechanisms of these interactions may reveal novel opportunities for future pharmacotherapy. The aim of the present review is to document recent literature regarding the impact of inflammatory mechanisms on the pathophysiology of the depressive disorder.

Dysregulation of the hypothalamus-pituitary-adrenal axis predicts some aspects of the behavioral response to chronic fluoxetine: association with hippocampal cell proliferation

In depressed patients, antidepressant resistance has been associated with dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis but the underlying mechanisms are poorly understood. The scope of this study was to try to create HPA-related antidepressant resistance in mice and to investigate adult hippocampal neurogenesis as a putative mechanism of antidepressant resistance. Mice were subjected to a 9 week Unpredictable Chronic Mild Stress (UCMS). After a 2 weeks drug-free period, mice were segregated in two groups, according to the percentage of corticosterone suppression after dexamethasone injection: High suppression (HS) and Low suppression (LS) mice. From the 5th week onwards, fluoxetine at a dose of 15 mg/kg (i.p.) was administered daily and at the end of 8th week, a battery of behavioral tests assessing the emotional, cognitive, and motor aspects of UCMS-induced depressive-like behavior was applied. Results show that fluoxetine-induced antidepressant effects were observed with higher amplitude in HS when compared to LS on various behavioral phenotypes, like coat state, novelty suppression of feeding, splash test and nest test. The same profile was found concerning the immunohistochimical analysis of ki-67 positive cells in the dentate gyrus of the hippocampus, which is a marker of neuronal proliferation, but not for doublecortin labeling. This suggests that the failure of fluoxetine to induce antidepressant effects may be associated to the poor ability of the compound to stimulate cell proliferation in the hippocampus.

Is unpredictable chronic mild stress (UCMS) a reliable model to study depression-induced neuroinflammation?

Unipolar depression is one of the leading causes of disability. The pathophysiology of depression is poorly understood. Evidence suggests that inflammation is associated with depression. For instance, pro-inflammatory cytokines are found to be elevated in the peripheral blood of depressed subjects. Cytokine immunotherapy itself is known to induce depressive symptoms. While the epidemiological and biochemical relationship between inflammation and depression is strong, little is known about the possible existence of neuroinflammation in depression. The use of animal models of depression such as the Unpredictable Chronic Mild Stress (UCMS) has already contributed to the elucidation of the pathophysiological mechanisms of depression such as decreased neurogenesis and HPA axis alterations. We used this model to explore the association of depressive-like behavior in mice with changes in peripheral pro-inflammatory cytokines IL-1β, TNFα and IL-6 level as well as the neuroinflammation by quantifying CD11b expression in brain areas known to be involved in the pathophysiology of depression. These areas include the cerebral cortex, the nucleus accumbens, the bed nucleus of the stria terminalis, the caudate putamen, the amygdala and the hippocampus. The results indicate that microglial activation is significantly increased in the infralimbic, cingulate and medial orbital cortices, nucleus accumbens, caudate putamen, amygdala and hippocampus of the mouse brain as a function of UCMS, while levels of pro-inflammatory cytokines did not differ among the groups. This finding suggests that neuroinflammation occurs in depression and may be implicated in the subject's behavioral response. They also suggest that UCMS could be a potentially reliable model to study depression-induced neuroinflammation.