Impaired immune response and barrier function in GSPD-1-deficient C. elegans infected with Klebsiella pneumoniae.

gspd-1-RNAi knockdown Caenorhabditis elegans was used as an immune-compromised model to investigate the role of G6PD in host-pathogen interactions. A shorted lifespan, increased bacterial burden and bacterial translocation were observed in gspd-1-knockdown C. elegans infected with Klebsiella pneumoniae (KP). RNAseq revealed that the innate immune pathway, including clc-1 and tsp-1, was affected by gspd-1 knockdown. qPCR confirmed that tight junction (zoo-1, clc-1) and immune-associated genes (tsp-1) were down-regulated in gspd-1-knockdown C. elegans and following infection with KP. The down-regulation of antimicrobial effector lysozymes, including lys-1, lys-2, lys-7, lys-8, ilys-2 and ilys-3, was found in gspd-1-knockdown C. elegans infected with KP. Deletion of clc-1, tsp-1, lys-7, and daf-2 in gspd-1-knockdown C. elegans infected with KP abolished the shorten lifespan seen in the Mock control. GSPD-1 deficiency in C. elegans resulted in bacterial accumulation and lethality, possibly due to a defective immune response. These findings indicate that GSPD-1 has a protective role in microbial defense in C. elegans by preventing bacterial colonization through bacterial clearance.

Sarcopenia in the Cirrhotic Patient: Current Knowledge and Future Directions.

Cirrhosis predisposes to abnormalities in energy, hormonal, and immunological homeostasis. Disturbances in these metabolic processes create susceptibility to sarcopenia or pathological muscle wasting. Sarcopenia is prevalent in cirrhosis and its presence portends significant adverse outcomes including the length of hospital stay, infectious complications, and mortality. This highlights the importance of identification of at-risk individuals with early nutritional, therapeutic and physical therapy intervention. This manuscript summarizes literature relevant to sarcopenia in cirrhosis, describes current knowledge, and elucidates possible future directions.

Smilax china root extract as a novel Glucose- 6-phosphate dehydrogenase inhibitor for the treatment of hepatocellular carcinoma.

A novel therapeutic strategy for cancer treatment is to target altered tumor metabolism. Glucose- 6-phosphate dehydrogenase (G6PD) has been recently discovered to be implicated in apoptosis and angiogenesis, making it an excellent target in cancer treatment. The current study aimed to screen the plant extracts library to find potent hits against G6PD through enzymatic assay. Protein expression was induced by IPTG and purified using Ni-NTA columns after transformation of the pET-24a-HmG6PD plasmid into E. coli BL21-DE3 strain. An enzymatic assay was established by using purified rG6PD protein, for the screening of G6PD inhibitors. Out of 46 plant extracts screened, the sixteen plant extracts have shown inhibitory activity against the G6PD enzyme. At doses from 1 to 4 µg/ml, this extract demonstrated concentration-dependent inhibition of G6PD with an IC50 value of I.397 µg/ml. Moreover, the anticancer activity evaluation against HepG2 cells determined Smilax china as a potent inhibitor of cancer cells (IC50 value of 16.017 µg/ml). The acute and subacute toxicities were not observed in mice with various concentrations (50, 100, 200 and 2000 mg/kg). Furthermore, to identify the compounds from Smilax china as G6PD inhibitors, a literature-based phytochemical investigation of Smilax china was conducted, and sixty compounds were docked against the NADP+ and G6P binding sites of G6PD. The results of this study showed that three compounds were Scirpusin A, Smilachinin and Daucosterol with MolDock Score of -156.832, -148.215, and -145.733 respectively, against NADP+ binding site of G6PD. Conclusively, Smilax china root extract could be a safer drug candidate for the treatment of hepatocellular carcinoma.

A practical strategy to develop isoform-selective near-infrared fluorescent probes for human cytochrome P450 enzymes.

Currently, the development of selective fluorescent probes toward targeted enzymes is still a great challenge, due to the existence of numerous isoenzymes that share similar catalytic capacity. Herein, a double-filtering strategy was established to effectively develop isoenzyme-specific fluorescent probe(s) for cytochrome P450 (CYP) which are key enzymes involving in metabolism of endogenous substances and drugs. In the first-stage of our filtering approach, near-infrared (NIR) fluorophores with alkoxyl group were prepared for the screening of CYP-activated fluorescent substrates using a CYPs-dependent incubation system. In the second stage of our filtering approach, these candidates were further screened using reverse protein-ligand docking to effectively determine CYP isoenzyme-specific probe(s). Using our double-filtering approach, probes S9 and S10 were successfully developed for the real-time and selective detection of CYP2C9 and CYP2J2, respectively, to facilitate high-throughput screening and assessment of CYP2C9-mediated clinical drug interaction risks and CYP2J2-associated disease diagnosis. These observations suggest that our strategy could be used to develop the isoform-specific probes for CYPs.

Synthesis of a versatile mitochondria-targeting small molecule for cancer near-infrared fluorescent imaging and radio/photodynamic/photothermal synergistic therapies.

Although as a mainstay modal for cancer treatment, the clinical effect of radiotherapy (RT) does not yet meet the need of cancer patients. Developing tumour-preferential radiosensitizers or combining RT with other treatments has been acknowledged highly necessary to enhance the efficacy of RT. The present study reported a multifunctional bioactive small-molecule (designated as IR-83) simultaneously exhibiting tumour-preferential accumulation, near-infrared imaging and radio/photodynamic/photothermal therapeutic effects. IR-83 was designed and synthesized by introducing 2-nitroimidazole as a radiosensitizer into the framework of heptamethine cyanine dyes inherently with tumour-targeting and photosensitizing effects. As results, IR-83 preferentially accumulated in tumours, suppressed tumour growth and metastasis by integrating radio/photodynamic/photothermal multimodal therapies. Mechanism studies showed that IR-83 accumulated in cancer cell mitochondria, induced excessive reactive oxygen species (ROS), and generated high heat after laser irradiation. On one hand, these phenomena led to mitochondrial dysfunction and a sharp decline in oxidative phosphorylation to lessen tissue oxygen consumption. On the other hand, excessive ROS in mitochondria destroyed the balance of antioxidants and oxidative stress balance by down-regulating the intracellular antioxidant system, and subsequently sensitized ionizing radiation-generated irreversible DNA double-strand breaks. Therefore, this study presented a promising radiosensitizer and a new alternative strategy to enhance RT efficacy via mitochondria-targeting multimodal synergistic treatment.

Advanced application of stimuli-responsive drug delivery system for inflammatory arthritis treatment.

Inflammatory arthritis is a major cause of disability in the elderly. This condition causes joint pain, loss of function, and deterioration of quality of life, mainly due to osteoarthritis (OA) and rheumatoid arthritis (RA). Currently, available treatment options for inflammatory arthritis include anti-inflammatory medications administered via oral, topical, or intra-articular routes, surgery, and physical rehabilitation. Novel alternative approaches to managing inflammatory arthritis, so far, remain the grand challenge owing to catastrophic financial burden and insignificant therapeutic benefit. In the view of non-targeted systemic cytotoxicity and limited bioavailability of drug therapies, a major concern is to establish stimuli-responsive drug delivery systems using nanomaterials with on-off switching potential for biomedical applications. This review summarizes the advanced applications of triggerable nanomaterials dependent on various internal stimuli (including reduction-oxidation (redox), pH, and enzymes) and external stimuli (including temperature, ultrasound (US), magnetic, photo, voltage, and mechanical friction). The review also explores the progress and challenges with the use of stimuli-responsive nanomaterials to manage inflammatory arthritis based on pathological changes, including cartilage degeneration, synovitis, and subchondral bone destruction. Exposure to appropriate stimuli induced by such histopathological alterations can trigger the release of therapeutic medications, imperative in the joint-targeted treatment of inflammatory arthritis.

Identification of a novel PHGDH covalent inhibitor by chemical proteomics and phenotypic profiling.

The first rate-limiting enzyme of the serine synthesis pathway (SSP), phosphoglycerate dehydrogenase (PHGDH), is hyperactive in multiple tumors, which leads to the activation of SSP and promotes tumorigenesis. However, only a few inhibitors of PHGDH have been discovered to date, especially the covalent inhibitors of PHGDH. Here, we identified withangulatin A (WA), a natural small molecule, as a novel covalent inhibitor of PHGDH. Affinity-based protein profiling identified that WA could directly bind to PHGDH and inactivate the enzyme activity of PHGDH. Biolayer interferometry and LC-MS/MS analysis further demonstrated the selective covalent binding of WA to the cysteine 295 residue (Cys295) of PHGDH. With the covalent modification of Cys295, WA blocked the substrate-binding domain (SBD) of PHGDH and exerted an allosteric effect to induce PHGDH inactivation. Further studies revealed that with the inhibition of PHGDH mediated by WA, the glutathione synthesis was decreased and intracellular levels of reactive oxygen species (ROS) were elevated, leading to the inhibition of tumor proliferation. This study indicates WA as a novel PHGDH covalent inhibitor, which identifies Cys295 as a novel allosteric regulatory site of PHGDH and holds great potential in developing anti-tumor agents for targeting PHGDH.

Chemical synthesis of a reported p47phox/p22phox inhibitor and characterization of its instability and irreproducible activity.

The nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) multi-subunit complex is a highly abundant and central source of reactive oxygen species. NOX2 is a key enzyme of the innate immune system involved in antibacterial response, but excessive NOX2 activity is involved in oxidative stress and inflammation in many diseases. Inhibition of NOX2 has great potential as a therapeutic strategy. An intriguing pharmacological approach for inhibiting NOX2 is to target the p47phox subunit and thereby block the protein-protein interaction with p22phox, whereby assembling and activation of NOX2 is prevented. However, the shallow binding pocket of p47phox makes it difficult to develop drug-like p47phox/p22phox inhibitors. Recently, the small molecule LMH001 was reported to inhibit the p47phox/p22phox interaction, reduce endothelial NOX2 activity, and protect mice from angiotensin II-induced vascular oxidative stress. These noteworthy results could have significant impact on the field of NOX2 pharmacology, as specific and efficient inhibitors are scarce. Here, we synthesized and tested LMH001 to have it available as a positive control. We established a robust synthetic route for providing LMH001, but subsequently we experienced that LMH001 is chemically unstable in aqueous buffer. In addition, neither LMH001 nor its breakdown products were able to inhibit the p47phox/p22phox interaction in a non-cellular fluorescence polarization assay. However, LHM001 was a weak inhibitor of NOX2 in a functional cell assay, but with same low potency as one of its breakdown products. These findings question the activity and suggested mechanism of LMH001 and constitute important information for other researchers interested in chemical probes for studying NOX2 biology.

Gradual reduction of susceptibility and enhanced detoxifying enzyme activities of laboratory-reared Aedes aegypti under exposure of temephos for 28 generations.

Temephos, an organophosphate insecticide, is widely accepted for the control of Aedes aegypti, vector of infectious diseases such as dengue, chikungunya, yellow fever, and zika. However, there are claims that repeated and indiscriminate use of temephos has resulted in resistance development in exposed mosquito populations. The present study attempts to evaluate the continuous performance of temephos on the Ae. aegypti population, in laboratory conditions, in terms of toxicity and the effect on marker enzymes associated with metabolic resistance. Results of the toxicity bioassay showed that after the initial exposure, toxicity increased till F4 generation by 1.65 fold, and continuous exposure resulted in a 7.83 fold reduction in toxicity at F28 generation. Percent mortality result showed a marked reduction in mortality with the passage of generations while using the same series of concentrations, viz. 2 ppm, which was 100 % lethal at the initial nine generations, could kill only 22.66 % at F28. Resistance to organophosphates is mainly governed by metabolic detoxifying enzyme families of esterases, glutathione-s-transferase, and cytochrome P450. Analysis of these metabolic detoxifying enzymes showed an inverse trend to toxicity (i.e. toxicity increased in early generations as enzyme activity dropped and then dropped as enzyme activity increased). At the initial exposure, enzyme activity decreased in 2-4 generations, however, repeated exposure led to a significant increase in all the metabolic detoxifying enzymes. From the toxicity level as well as marker enzyme bioassay results, it can be inferred that mosquitoes showed increased detoxification in generational time with an increase in enzymes associated with metabolic detoxification. In conclusion, repeated application of temephos led to resistance development in Ae. aegypti which may be associated with the increase in metabolic detoxifying enzyme activities.

Naringin prevents cyclophosphamide-induced erythrocytotoxicity in rats by abrogating oxidative stress.

Earlier reports have shown that Cyclophosphamide (CYCP), an anti-malignant drug, elicited cytotoxicity; and that naringin has several beneficial potentials against oxidative stress and dyslipidaemias. We investigated the influence of naringin on free radical scavenging, cellular integrity, cellular ATP, antioxidants, oxidative stress, and lipid profiles in the CYCP-induced erythrocytotoxicity rat model. Rats were pretreated orally by gavage for fourteen consecutive days with three doses (50, 100, and 200 mg/kg) naringin before single CYCP (200 mg/kg, i.p.) administration. Afterwards, the rats were sacrificed. Naringin concentrations required for 50 % scavenging hydrogen peroxide and nitric oxide radical were 0.27 mg/mL and 0.28 mg/mL, respectively. Naringin pretreatment significantly (p < 0.05) protected erythrocytes plasma membrane architecture and integrity by abolishing CYCP-induced decrease in the activity of erythrocyte LDH (a marker of ATP). Pretreatment with naringin remarkably (p < 0.05) reversed CYCP-induced decreases in the erythrocytes glutathione levels, activities of glutathione-S-transferase, catalase, glutathione peroxidase, and glutathione reductase; attenuated CYCP-mediated increases in erythrocytes levels of malondialdehyde, nitric oxide, and major lipids (cholesterol, triacylglycerol, phospholipids, and non-esterified fatty acids). Taken together, different acute pretreatment doses of naringin might avert CYCP-mediated erythrocytes dysfunctions via its antioxidant, free-radical scavenging, and anti-dyslipidaemia properties.

Role of Oxidative Stress and Autophagy in Thoracic Aortic Aneurysms.

Thoracic aortic aneurysms (TAA) pathogenesis and progression include many mechanisms. The authors investigated the role of autophagy, oxidative stress, and endothelial dysfunction in 36 TAA patients and 23 control patients. Univariable and multivariable analyses were performed. TAA patients displayed higher oxidative stress and endothelial dysfunction then control patients. Autophagy in the TAA group was reduced. The association of oxidative stress and autophagy with aortic disease supports the role of these processes in TAA. The authors demonstrate a putative role of Nox2 and autophagy dysregulation in human TAA. These findings could pinpoint novel treatment targets to prevent or limit TAA progression.

Nicotinamide Adenine Dinucleotide Phosphate Oxidases Are Everywhere in Brain Disease, but Not in Huntington's Disease?

Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by neuronal loss and tissue atrophy mainly in the striatum and cortex. In the early stages of the disease, impairment of neuronal function, synaptic dysfunction and white matter loss precedes neuronal death itself. Relative to other neurodegenerative diseases such as Alzheimer's and Parkinson's disease and Amyotrophic Lateral Sclerosis, where the effects of either microglia or NADPH oxidases (NOXs) are recognized as important contributors to disease pathogenesis and progression, there is a pronounced lack of information in HD. This information void contrasts with evidence from human HD patients where blood monocytes and microglia are activated well before HD clinical symptoms (PET scans), and the clear signs of oxidative stress and inflammation in post mortem HD brain. Habitually, NOX activity and oxidative stress in the central nervous system (CNS) are equated with microglia, but research of the last two decades has carved out important roles for NOX enzyme function in neurons. Here, we will convey recent information about the function of NOX enzymes in neurons, and contemplate on putative roles of neuronal NOX in HD. We will focus on NOX-produced reactive oxygen species (ROS) as redox signaling molecules in/among neurons, and the specific roles of NOXs in important processes such as neurogenesis and lineage specification, neurite outgrowth and growth cone dynamics, and synaptic plasticity where NMDAR-dependent signaling, and long-term depression/potentiation are redox-regulated phenomena. HD animal models and induced pluripotent stem cell (iPSC) studies have made it clear that the very same physiological processes are also affected in HD, and we will speculate on possible roles for NOX in the pathogenesis and development of disease. Finally, we also take into account the limited information on microglia in HD and relate this to any contribution of NOX enzymes.

Cinnamomum zeylanicum Blume (Ceylon cinnamon) bark extract attenuates doxorubicin induced cardiotoxicity in Wistar rats.

Anti-tumour efficacy of doxorubicin is hindered by the cumulative dose-dependent cardiotoxicity induced by reactive oxygen species during its metabolism. As Cinnamomum zeylanicum has proven antioxidant potential, objective of this study was to investigate the cardioprotective activity of Cinnamomum bark extract against doxorubicin induced cardiotoxicity in Wistar rats. Physicochemical and phytochemical analysis was carried out and dose response effect and the cardioprotective activity of Cinnamomum were determined in vivo. 180 mg/kg dexrazoxane was used as the positive control. Plant extracts were free of heavy metals and toxic phytoconstituents. In vivo study carried out in Wistar rats revealed a significant increase (p < 0.05) in cardiac troponin I, NT-pro brain natriuretic peptide, AST and LDH concentrations in the doxorubicin control group (18 mg/kg) compared to the normal control. Rats pre-treated with the optimum dosage of Cinnmamomum (2.0 g/kg) showed a significant reduction (p < 0.05) in all above parameters compared to the doxorubicin control. A significant reduction was observed in the total antioxidant capacity, reduced glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase activity while the lipid peroxidation and myeloperoxidase activity were significantly increased in the doxorubicin control group compared to the normal control (p < 0.05). Pre-treatment with Cinnamomum bark showed a significant decrease in lipid peroxidation, myeloperoxidase activity and significant increase in rest of the parameters compared to the doxorubicin control (p < 0.05). Histopathological analysis revealed a preserved appearance of the myocardium and lesser degree of cellular changes of necrosis in rats pre-treated with Cinnamomum extract. In conclusion, Cinnamomum bark extract has the potential to significantly reduce doxorubicin induced oxidative stress and inflammation in Wistar rats.

Deletion of Von Willebrand A Domain Containing Protein (VWA8) raises activity of mitochondrial electron transport chain complexes in hepatocytes.

VWA8 (Von Willebrand A Domain Containing Protein 8) is a AAA+ ATPase that is localized to the mitochondrial matrix and is widely expressed in highly energetic tissues. Originally found to be higher in abundance in livers of mice fed a high fat diet, deletion of the VWA8 gene in differentiated mouse AML12 hepatocytes unexpectedly produced a phenotype of higher mitochondrial and nonmitochondrial oxidative metabolism, higher ROS (reactive oxygen species) production mainly from NADPH oxidases, and increased HNF4a expression. The purposes of this study were first, to determine whether higher mitochondrial oxidative capacity in VWA8 null hepatocytes is the product of higher capacity in all aspects of the electron transport chain and oxidative phosphorylation, and second, the density of cristae in mitochondria and mitochondrial content was measured to determine if higher mitochondrial oxidative capacity is accompanied by greater cristae area and mitochondrial abundance. Electron transport chain complexes I, II, III, and IV activities all were higher in hepatocytes in which the VWA8 gene had been deleted using CRISPR/Cas9. A comparison of abundance of proteins in electron transport chain complexes I, III and ATP synthase previously determined using an unbiased proteomics approach in hepatocytes in which VWA8 had been deleted showed agreement with the activity assays. Mitochondrial cristae, the site where electron transport chain complexes are located, were quantified using electron microscopy and stereology. Cristae density, per mitochondrial area, was almost two-fold higher in the VWA8 null cells (P < 0.01), and mitochondrial area was two-fold higher in the VWA8 null cells (P < 0.05). The results of this study allow us to conclude that despite sustained, higher ROS production in VWA8 null cells, a global mitochondrial compensatory response was maintained, resulting in overall higher mitochondrial oxidative capacity.

Targeting redox-altered plasticity to reactivate synaptic function: A novel therapeutic strategy for cognitive disorder.

Redox-altered plasticity refers to redox-dependent reversible changes in synaptic plasticity via altering functions of key proteins, such as N-methyl-d-aspartate receptor (NMDAR). Age-related cognitive disorders includes Alzheimer's disease (AD), vascular dementia (VD), and age-associated memory impairment (AAMI). Based on the critical role of NMDAR-dependent long-term potentiation (LTP) in memory, the increase of reactive oxygen species in cognitive disorders, and the sensitivity of NMDAR to the redox status, converging lines have suggested the redox-altered NMDAR-dependent plasticity might underlie the synaptic dysfunctions associated with cognitive disorders. In this review, we summarize the involvement of redox-altered plasticity in cognitive disorders by presenting the available evidence. According to reports from our laboratory and other groups, this "redox-altered plasticity" is more similar to functional changes rather than organic injuries, and strategies targeting redox-altered plasticity using pharmacological agents might reverse synaptic dysfunctions and memory abnormalities in the early stage of cognitive disorders. Targeting redox modifications for NMDARs may serve as a novel therapeutic strategy for memory deficits.

Alcohol-associated liver disease: A review on its pathophysiology, diagnosis and drug therapy.

One of the global burdens of health care is an alcohol-associated liver disease (ALD) and liver-related death which is caused due to acute or chronic consumption of alcohol. Chronic consumption of alcohol damage the normal defense mechanism of the liver and likely to disturb the gut barrier system, mucosal immune cells, which leads to decreased nutrient absorption. Therapy of ALD depends upon the spectrum of liver injury that causes fatty liver, hepatitis, and cirrhosis. The foundation of therapy starts with abstinence from alcohol. Corticosteroids are used for the treatment of ALD but due to poor acceptance, continuing mortality, and identification of tumor necrosis factor-alpha as an integral component in pathogenesis, recent studies focus on pentoxifylline and, antitumor necrosis factor antibody to neutralize cytokines in the therapy of severe alcoholic hepatitis. Antioxidants also play a significant role in the treatment but till today there is no universally accepted therapy available for any stage of ALD. The treatment aspects need to restore the gut functions and require nutrient-based treatments to regulate the functions of the gut system and prevent liver injury. The vital action of saturated fatty acids greatly controls the gut barrier. Overall, this review mainly focuses on the mechanism of alcohol-induced metabolic dysfunction, contribution to liver pathogenesis, the effect of pregnancy, and targeted therapy of ALD.

Neomenthol prevents the proliferation of skin cancer cells by restraining tubulin polymerization and hyaluronidase activity.

Introduction: Neomenthol, a cyclic monoterpenoid, is a stereoisomer of menthol present in the essential oil of Mentha spp. It is used in food as a flavoring agent, in cosmetics and medicines because of its cooling effects. However, neomenthol has not been much explored for its anticancer potential. Additionally, targeting hyaluronidase, Cathepsin-D, and ODC by phytochemicals is amongst the efficient approach for cancer prevention and/or treatment. Objectives: To investigate the molecular and cell target-based antiproliferative potential of neomenthol on human cancer (A431, PC-3, K562, A549, FaDu, MDA-MB-231, COLO-205, MCF-7, and WRL-68) and normal (HEK-293) cell lines. Methods: The potency of neomenthol was evaluated on human cancer and normal cell line using SRB, NRU and MTT assays. The molecular target based study of neomenthol was carried out in cell-free and cell-based test systems. Further, the potency of neomenthol was confirmed by quantitative real-time PCR analysis and molecular docking studies. The in vivo anticancer potential of neomenthol was performed on mice EAC model and the toxicity examination was accomplished through in silico, ex vivo and in vivo approaches. Results: Neomenthol exhibits a promising activity (IC50 17.3 ± 6.49 µM) against human epidermoid carcinoma (A431) cells by arresting the G2/M phase and increasing the number of sub-diploid cells. It significantly inhibits hyaluronidase activity (IC50 12.81 ± 0.01 µM) and affects the tubulin polymerization. The expression analysis and molecular docking studies support the in vitro molecular and cell target based results. Neomenthol prevents EAC tumor formation by 58.84% and inhibits hyaluronidase activity up to 10% at 75 mg/kg bw, i.p. dose. The oral dose of 1000 mg/kg bw was found safe in acute oral toxicity studies. Conclusion: Neomenthol delayed the growth of skin carcinoma cells by inhibiting the tubulin polymerization and hyaluronidase activity, which are responsible for tumor growth, metastasis, and angiogenesis.

Implications of hydrogen sulfide in liver pathophysiology: Mechanistic insights and therapeutic potential.

BACKGROUND: Over the last several decades, hydrogen sulfide (H2S) has been found to exert multiple physiological functions in mammal systems. The endogenous production of H2S is primarily mediated by cystathione ß-synthase (CBS), cystathione γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3-MST). These enzymes are widely expressed in the liver tissues and regulate hepatic functions by acting on various molecular targets. AIM OF REVIEW: In the present review, we will highlight the recent advancements in the cellular events triggered by H2S under liver diseases. The therapeutic effects of H2S donors on hepatic diseases will also be discussed. KEY SCIENTIFIC CONCEPTS OF REVIEW: As a critical regulator of liver functions, H2S is critically involved in the etiology of various liver disorders, such as nonalcoholic steatohepatitis (NASH), hepatic fibrosis, hepatic ischemia/reperfusion (IR) injury, and liver cancer. Targeting H2S-producing enzymes may be a promising strategy for managing hepatic disorders.

A versatile tool in controlling aggregation and Ag nanoparticles assisted in vitro folding of thermally denatured zDHFR.

BACKGROUND: Proteins have tendency to form inactive aggregates at higher temperatures due to thermal instability. Maintenance of thermal stability is essential to gain the protein in sufficient quantity and biologically active form during their commercial production. METHODS: BL21-DE3 Rosetta E. coli cells which contains plasmid pET43.1a vector was used for producing zDHFR protein commercially. The purification of N-terminal Histidine tagged zDHFR was performed by Immobilized Metal Ion chromatography (IMAC). Investigations were performed in existence and non existence of Silver nanoparticles (AgNPs). The inactivation kinetics of zDHFR in existence and non existence of AgNPs were monitored over a range of 40-80 °C as monitored by UV-Visible absorption spectroscopy. RESULTS: The protein completely lost its activity at 55 °C. Kinetics of inactivated zDHFR follows first order model in presence and absence of AgNPs. Decrease in rate constant (k) values at respective temperatures depicts that AgNPs contribute in the thermostability of the protein. AgNPs also assists in regaining the activity of zDHFR protein. CONCLUSIONS: AgNPs helps in maintaining thermostability and reducing the aggregation propensity of zDHFR protein. GENERAL SIGNIFICANCE: Result explains that AgNPs are recommended as a valuable system in enhancing the industrial production of biologically active zDHFR protein which is an important component in folate cycle and essential for survival of cells and prevents the protein from being aggregated.

Kynurenine pathway in Parkinson's disease-An update.

Parkinson's disease (PD) is a complex multi-factorial neurodegenerative disorder where various altered metabolic pathways contribute to the progression of the disease. Tryptophan (TRP) is a major precursor in kynurenine pathway (KP) and it has been discussed in various in vitro studies that the metabolites quinolinic acid (QUIN) causes neurotoxicity and kynurenic acid (KYNA) acts as neuroprotectant respectively. More studies are also focused on the effects of other KP metabolites and its enzymes as it has an association with ageing and PD pathogenesis. Until now, very few studies have targeted the role of genetic mutations in abnormal KP metabolism in adverse conditions of PD. Therefore, the present review gives an updated research studies on KP in connection with PD. Moreover, the review emphasizes on the urge for the development of biomarkers and also this would be an initiative in generating an alternative therapeutic approach for PD.