Fisetin induces G2/M phase arrest and caspase-mediated cleavage of p21Cip1 and p27Kip1 leading to apoptosis and tumor growth inhibition in HNSCC.

The anticancer potential and associated mechanisms of flavonoid fisetin are yet to be fully investigated on human head and neck squamous cell carcinoma (HNSCC). In the present study, fisetin (25-75 µM for 24-48 h) dose-dependently inhibited growth and induced death in HNSCC Cal33 and UM-SCC-22B cells, without showing any death in normal cells. Fisetin (25-50 µM) induced G2/M phase arrest via decrease in Cdc25C, CDK1, cyclin B1 expression, and an increase in p53(S15). A concentration-dependent increase in fisetin-induced DNA damage and apoptosis in HNSCC cells was authenticated by comet assay, gamma-H2A.X(S139) phosphorylation, and marked cleavage of PARP protein. Interestingly, fisetin-induced cell death occurred independently of p53 and reactive oxygen species production. The activation of JNK and inhibition of PI3K/Akt, ERK1/2, EGFR, and STAT-3 signaling were identified. Further, fisetin-induced apoptosis was mediated, in part, via p21Cip1 and p27Kip1 cleavage by caspase, which was reversed by z-VAD-FMK, a pan-caspase inhibitor. Subsequently, fisetin was also found to induce autophagy; nevertheless, autophagy attenuation exaggerated apoptosis. Oral fisetin (50 mg/kg body weight) treatment to establish Cal33 xenograft in mice for 19 days showed 73% inhibition in tumor volume (p < 0.01) along with a decrease in Ki67-positive cells and an increase in cleaved caspase-3 level in tumors. Consistent with the effect of 50 µM fisetin in vitro, the protein levels of p21Cip1 and P27Kip1 were also decreased by fisetin in tumors. Together, these findings showed strong anticancer efficacy of fisetin against HNSCC with downregulation of EGFR-Akt/ERK1/2-STAT-3 pathway and activation of JNK/c-Jun, caspases and caspase-mediated cleavage of p21Cip1 and p27Kip1.

Correlation of severity & clinical outcomes of COVID-19 with virus variants: A prospective, multicentre hospital network study.

BACKGROUND OBJECTIVES: The clinical course of COVID-19 and its prognosis are influenced by both viral and host factors. The objectives of this study were to develop a nationwide platform to investigate the molecular epidemiology of SARS-CoV-2 (Severe acute respiratory syndrome Corona virus 2) and correlate the severity and clinical outcomes of COVID-19 with virus variants. METHODS: A nationwide, longitudinal, prospective cohort study was conducted from September 2021 to December 2022 at 14 hospitals across the country that were linked to a viral sequencing laboratory under the Indian SARS-CoV-2 Genomics Consortium. All participants (18 yr and above) who attended the hospital with a suspicion of SARS-CoV-2 infection and tested positive by the reverse transcription-PCR method were included. The participant population consisted of both hospitalized as well as outpatients. Their clinical course and outcomes were studied prospectively. Nasopharyngeal samples collected were subjected to whole genome sequencing to detect SARS-CoV-2 variants. RESULTS: Of the 4972 participants enrolled, 3397 provided samples for viral sequencing and 2723 samples were successfully sequenced. From this, the evolution of virus variants of concern including Omicron subvariants which emerged over time was observed and the same reported here. The mean age of the study participants was 41 yr and overall 49.3 per cent were female. The common symptoms were fever and cough and 32.5 per cent had comorbidities. Infection with the Delta variant evidently increased the risk of severe COVID-19 (adjusted odds ratio: 2.53, 95% confidence interval: 1.52, 4.2), while Omicron was milder independent of vaccination status. The independent risk factors for mortality were age >65 yr, presence of comorbidities and no vaccination. INTERPRETATION CONCLUSIONS: The authors believe that this is a first-of-its-kind study in the country that provides real-time data of virus evolution from a pan-India network of hospitals closely linked to the genome sequencing laboratories. The severity of COVID-19 could be correlated with virus variants with Omicron being the milder variant.

Synthesis of optically active SARS-CoV-2 Mpro inhibitor drug nirmatrelvir (Paxlovid): an approved treatment of COVID-19.

Nirmatrelvir (Paxlovid) is an FDA approved drug that targets SARS-COV-2 3CLprotease. We report an optically active synthesis of nirmatrelvir that avoids a critical epimerization step. Our initial coupling of gem-dimethyl bicyclo[3.1.0]proline methyl ester with tert-leucine-trifluoroacetamide using standard coupling reagents, EDC and HOBt, provided the corresponding dipeptide derivative in excellent yield, however, a significant epimerization was observed at the tert-leucine bearing chiral center. To circumvent this epimerization problem, we developed a ZnCl2-mediated direct N-trifluroacetylation of Boc-derivatives for the synthesis of nirmatrelvir. This protocol has been utilized for N-acyl bond formation with other anhydrides without epimerization. The present synthetic route can be useful for the synthesis of structural variants of nirmatrelvir without significant epimerization.

Cherenkov Radiation in Optical Fibres as a Versatile Machine Protection System in Particle Accelerators.

Machine protection systems in high power particle accelerators are crucial. They can detect, prevent, and respond to events which would otherwise cause damage and significant downtime to accelerator infrastructure. Current systems are often resource heavy and operationally expensive, reacting after an event has begun to cause damage; this leads to facilities only covering certain operational modes and setting lower limits on machine performance. Presented here is a new type of machine protection system based upon optical fibres, which would be complementary to existing systems, elevating existing performance. These fibres are laid along an accelerator beam line in lengths of ∼100 m, providing continuous coverage over this distance. When relativistic particles pass through these fibres, they generate Cherenkov radiation in the optical spectrum. This radiation propagates in both directions along the fibre and can be detected at both ends. A calibration based technique allows the location of the Cherenkov radiation source to be pinpointed to within 0.5 m with a resolution of 1 m. This measurement mechanism, from a single device, has multiple applications within an accelerator facility. These include beam loss location monitoring, RF breakdown prediction, and quench prevention. Detailed here are the application processes and results from measurements, which provide proof of concept for this device for both beam loss monitoring and RF breakdown detection. Furthermore, highlighted are the current challenges for future innovation.

Reprint of Organic waste conversion through anaerobic digestion: A critical insight into the metabolic pathways and microbial interactions.

Anaerobic digestion is a promising method for energy recovery through conversion of organic waste to biogas and other industrial valuables. However, to tap the full potential of anaerobic digestion, deciphering the microbial metabolic pathway activities and their underlying bioenergetics is required. In addition, the behavior of organisms in consortia along with the analytical abilities to kinetically measure their metabolic interactions will allow rational optimization of the process. This review aims to explore the metabolic bottlenecks of the microbial communities adopting latest advances of profiling and 13C tracer-based analysis using state of the art analytical platforms (GC, GC-MS, LC-MS, NMR). The review summarizes the phases of anaerobic digestion, the role of microbial communities, key process parameters of significance, syntrophic microbial interactions and the bottlenecks that are critical for optimal bioenergetics and enhanced production of valuables. Considerations into the designing of efficient synthetic microbial communities as well as the latest advances in capturing their metabolic cross talk will be highlighted. The review further explores how the presence of additives and inhibiting factors affect the metabolic pathways. The critical insight into the reaction mechanism covered in this review may be helpful to optimize and upgrade the anaerobic digestion system.

Organic waste conversion through anaerobic digestion: A critical insight into the metabolic pathways and microbial interactions.

Anaerobic digestion is a promising method for energy recovery through conversion of organic waste to biogas and other industrial valuables. However, to tap the full potential of anaerobic digestion, deciphering the microbial metabolic pathway activities and their underlying bioenergetics is required. In addition, the behavior of organisms in consortia along with the analytical abilities to kinetically measure their metabolic interactions will allow rational optimization of the process. This review aims to explore the metabolic bottlenecks of the microbial communities adopting latest advances of profiling and 13C tracer-based analysis using state of the art analytical platforms (GC, GC-MS, LC-MS, NMR). The review summarizes the phases of anaerobic digestion, the role of microbial communities, key process parameters of significance, syntrophic microbial interactions and the bottlenecks that are critical for optimal bioenergetics and enhanced production of valuables. Considerations into the designing of efficient synthetic microbial communities as well as the latest advances in capturing their metabolic cross talk will be highlighted. The review further explores how the presence of additives and inhibiting factors affect the metabolic pathways. The critical insight into the reaction mechanism covered in this review may be helpful to optimize and upgrade the anaerobic digestion system.

Asymmetric 1,2-Carbamoyl Rearrangement of Lithiated Chiral Oxazolidine Carbamates and Diastereoselective Synthesis of α-Hydroxy Amides.

Asymmetric 1,2-carbamoyl rearrangement of lithiated 2-alkenyl carbamates has been investigated. Deprotonation of chiral 2-alkenyl oxazolidine carbamates with sec-butyllithium in ether at -78 °C followed by warming of the resulting 1-lithio-2-alkenyl derivatives to room temperature resulted in 1,2-carbamoyl rearrangement to provide α-hydroxy amides. The rearrangement proceeded with excellent diastereoselectivity and in good to excellent isolated yield of the α-hydroxy amide derivatives. The substrate scope of the reaction was investigated with a variety of 2-alkenyl and benzyl oxazolidine carbamates. A stereochemical model is provided to explain the stereochemical outcome associated with the rearrangement. Acid-catalyzed removal of the chiral oxazolidine afforded α-hydroxy acid in high optical purity.

Phenolic and flavonoid contents and antioxidant activity of an endophytic fungus Nigrospora sphaerica (EHL2), inhabiting the medicinal plant Euphorbia hirta (dudhi) L.

Since endophytic fungi are pivotal sources of various bioactive natural compounds, the present study is aimed to investigate the antioxidant compounds of the endophytic fungus Nigrospora sphaerica isolated from a pantropical weed, Euphorbia hirta L. The fungus was fermented in four different media and each filtered broth was sequentially extracted in various solvents. Crude extracts collected from different solvents were subjected to phytochemical analysis and antioxidant activity. The total phenolic content (TPC) and total flavonoid content (TFC) were maximal in ethyl acetate crude extract (EtOAcE) of endophyte fermented in potato dextrose broth (PDB) medium (77.74 ± 0.046mgGAE/g and 230.59 ± 2.0 mgRE/g) with the highest 96.80% antioxidant activity. However, TPC and TFC were absent in hexane extract of Czapek Dox broth (CDB) medium exhibiting the lowest 4.63 ± 2.75% activity. The EtOAcE (PDB) showed a positive correlation between TFC and antiradical activity (R2 = 0.762; P < 0.05), whereas a high positive correlation was noticed between TPC and antioxidant activity (R2 = 0.989; P < 0.05). Furthermore, to determine the antioxidant activity, EtOAcE (PDB) was subjected to TLC bioautography-based partial purification, while GC/MS analysis of the partial purified extract was done to confirm the presence of phenolics along with antioxidant compounds that resulted in the detection of 2,4-Di-tert-butylphenol (13.83%), a phenolic compound accountable for the antioxidant potential. Conclusively, N. sphaerica is a potential candidate for natural antioxidant.

Bioactive potential evaluation and purification of compounds from an endophytic fungus Diaporthe longicolla, a resident of Saraca asoca (Roxb.) Willd.

An endophytic fungus (L3), isolated from the leaf tissues of Saraca asoca was identified as D. longicolla by microscopic and molecular methods. The crude extracts of D. longicolla revealed to harbor seven compounds in GC-MS analysis which was subjected to a thin layer chromatography (TLC) for purification and separation of bioactive ingredients. The partially purified fraction from TLC displayed the presence of 2-tridecene (Z) (RT-14.50), 5-tridecene (E) (RT-16.65) and 2,4-di-tert-butylphenol (RT-13.92) in GC-MS. High-performance liquid chromatography (HPLC) was performed to further purify the constituents which led to the collection of 2,4-di-tert-butyl phenol (RT-2.34) with excellent antioxidant activity and antibacterial activity against methicillin resistance Staphylococcus aureus (MRSA).

Highly Diastereoselective Intramolecular Asymmetric Oxidopyrylium-olefin [5 + 2] Cycloaddition and Synthesis of 8-Oxabicyclo[3.2.1]oct-3-enone Containing Ring Systems.

We have the investigated base mediated asymmetric intramolecular oxidopyrylium-alkene [5 + 2]-cycloaddition reaction which resulted in the synthesis of functionalized tricyclic ring systems containing an 8-oxabicyclo[3.2.1]octane core. Intramolecular cycloaddition constructed two new rings, three new stereogenic centers, and provided a tricyclic cycloadduct with high diastereoselectivity and isolated yield. We incorporated an α-chiral center and an alkoxy alkene tether on the substrates and examined the effect of the size of alkyl groups and alkene tether length on diastereoselectivity. The requisite substrates for the oxidopyrylium-alkene cycloaddition reaction were synthesized in a few steps involving alkylation of optically active α-hydroxy amide, furyllithium addition, reduction of resulting ketone, and Achmatowicz reaction followed by acylation of a lactol intermediate. We have proposed stereochemical models for the [5 + 2] cycloaddition reaction via the oxidopyrylium ylide. Interestingly, the alkoxy substituent on the stereocenter and the chain length are responsible for the degree of stereoselectivity of the cycloadduct.

Intraperitoneal exposure of iron oxide nanoparticles causes dose-dependent toxicity in Wistar rats.

Nanoparticles of iron oxide, with diameters beteween 1 to 100 nm, have notable implications for human health and well being. In the current study, we have investigated the effects of iron oxide nanoparticles (IONP) exposure on general physiology and health of adult Wistar rats. IONP used in the study had spherical shape and average size in the range of 15-20 nm. A total of eight groups of rats were repeatedly injected with 0 (control), 20, 40, and 80 mg IONP per kg body weight intraperitoneally under two different exposure schemes (sub-acute and sub-chronic). IONP exposure caused significant changes in lungs, liver, and kidney indices in both exposure schemes. Sub-acute exposure did not affect body weight gain in treated rats, but longer duration exposure was responsible for significant reduction in body weight. Mesenteries, visceral fatty tissues, and visceral peritoneal membranes demonstrated apparent accumulations of IONP in a dose and time-dependent manner. Hematological analysis showed that total RBC count, hemoglobin content, hematocrit, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and mean platelet volume (MPV) were not affected by IONP exposure. Total lymphocyte count, however, was elevated in low- and mid-dose treated rats, but not in high-dose group. Serum lactate dehydrogenase (LDH) increased significantly in rats treated with mid and high doses as compared to control. Serum creatinine and blood urea nitrogen levels were also significantly altered in treated rats. Histological study found significant hepatic damage and mild spleen toxicity. Our report suggests that IONP exhibit significant toxicity in rats.

Chloropyridinyl Esters of Nonsteroidal Anti-Inflammatory Agents and Related Derivatives as Potent SARS-CoV-2 3CL Protease Inhibitors.

We report the design and synthesis of a series of new 5-chloropyridinyl esters of salicylic acid, ibuprofen, indomethacin, and related aromatic carboxylic acids for evaluation against SARS-CoV-2 3CL protease enzyme. These ester derivatives were synthesized using EDC in the presence of DMAP to provide various esters in good to excellent yields. Compounds are stable and purified by silica gel chromatography and characterized using 1H-NMR, 13C-NMR, and mass spectral analysis. These synthetic derivatives were evaluated in our in vitro SARS-CoV-2 3CLpro inhibition assay using authentic SARS-CoV-2 3CLpro enzyme. Compounds were also evaluated in our in vitro antiviral assay using quantitative VeroE6 cell-based assay with RNAqPCR. A number of compounds exhibited potent SARS-CoV-2 3CLpro inhibitory activity and antiviral activity. Compound 9a was the most potent inhibitor, with an enzyme IC50 value of 160 nM. Compound 13b exhibited an enzyme IC50 value of 4.9 µM. However, it exhibited a potent antiviral EC50 value of 24 µM in VeroE6 cells. Remdesivir, an RdRp inhibitor, exhibited an antiviral EC50 value of 2.4 µM in the same assay. We assessed the mode of inhibition using mass spectral analysis which suggested the formation of a covalent bond with the enzyme. To obtain molecular insight, we have created a model of compound 9a bound to SARS-CoV-2 3CLpro in the active site.

Photocatalytic TiO2/CdS/ZnS nanocomposite induces Bacillus subtilis cell death by disrupting its metabolism and membrane integrity.

Titanium dioxide (TiO2) is widely characterized for its application in clinical diagnostics, therapeutics, cosmetics, nutrition, and environment management. Despite enormous potential, its dependence on ultraviolet (UV) light for photocatalytic activity limits its commercialization. Accordingly in the present study, a photo catalytically superior ternary complex of TiO2 with Cadmium sulfide/Zinc sulfide (CdS/ZnS) has been synthesized, as well as, characterized for photo-induced antimicrobial activity. The band gap of crystalline TiO2/CdS/ZnS nanocomposite has been reduced (2.26 eV) and nanocomposite has shown the optimal photo-activation at 590 nm. TiO2 nanocomposite has significant bactericidal activity in visible light (P < 0.01). Exposure of the TiO2 nanocomposite affected the cellular metabolism by altering the 1681 metabolic features (P < 0.001) culminating in poor cellular survivability. Additionally, photo-induced reactive oxygen species generation through nanocomposite disrupts the microbial cellular structure. The present study synthesized photocatalytic nanocomposite as well as unveiled the holistic cellular effect of theTiO2/CdS/ZnS nanocomposite. Additionally, the present study also indicated the potential application of TiO2/CdS/ZnS nanocomposite for sustainable environment management, therapeutics, and various industries. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12088-021-00973-z.

Probiotics of Diverse Origin and Their Therapeutic Applications: A Review.

The increased awareness about the harmful effects of excessive use of antibiotics has created an interest in probiotics due to its beneficial effects on gut microbiota. These advantages of probiotics have attracted researchers to find out effects on human metabolism and their role in the treatment of diverse types of diseases or disorders. Additionally, they are clinically used as biocontrol agents in the treatment of mental disorders, anticancer agents and in decreasing the threat of necrotizing enterocolitis in premature infants. In this review, we have focused on various kinds of probiotics and various nondairy substrates for their production. We have also included the importance of probiotics in the treatment of metabolic disorders, type II diabetes and infectious diseases. Furthermore, this review emphasizes applications of probiotics originated from different organisms. Their future health perspectives are discussed to gain insight into their applications.KEY TEACHING POINTSThe global market of probiotics is enormously rising day by day due to its highly beneficial effect on human microbiota.Additionally, these are used as biocontrol agents; mental disorders prevent cancer and decrease the threat of necrotizing enterocolitis (NEC) in premature infants.This review focuses on various kinds of sources of probiotics and various non-dairy substrates for the production of probiotics.The importance of probiotics in the treatment of metabolic disorders, type II diabetes control, cancer and treatment of infectious diseases are also described.It emphasizes diversified probiotics and their applications in various human health aspects and future perspectives.

Efficient engineered probiotics using synthetic biology approaches: A review.

The uses of probiotics-based food supplements are getting emphasis due to their power to ensure better health conditions. Probiotics have diverse and significant applications in the health sector, so probiotic strains require an understanding of the genome level organizations. Probiotics elucidate various functional parameters that control their metabolic functions. In this review, we have compiled aspects of synthetic biology, which are used for the optimization of metabolic processes in probiotics for their use as a supplement in allopathic medicines. Synthetic biology approaches provide information about diverse biosynthetic pathways and also facilitate the novel metabolic engineering approaches for probiotics strain improvement. We have discussed the synthetic biology approaches for producing engineered probiotics via genetic circuits, expression systems, and genome editing tools like CRISPR-Cas and PEVLAB. This review also enlightens future challenges in the development of engineered probiotics.

A review of metabolic potential of human gut microbiome in human nutrition.

The human gut contains a plethora of microbes, providing a platform for metabolic interaction between the host and microbiota. Metabolites produced by the gut microbiota act as a link between gut microbiota and its host. These metabolites act as messengers having the capacity to alter the gut microbiota. Recent advances in the characterization of the gut microbiota and its symbiotic relationship with the host have provided a platform to decode metabolic interactions. The human gut microbiota, a crucial component for dietary metabolism, is shaped by the genetic, epigenetic and dietary factors. The metabolic potential of gut microbiota explains its significance in host health and diseases. The knowledge of interactions between microbiota and host metabolism, as well as modification of microbial ecology, is really beneficial to have effective therapeutic treatments for many diet-related diseases in near future. This review cumulates the information to map the role of human gut microbiota in dietary component metabolism, the role of gut microbes derived metabolites in human health and host-microbe metabolic interactions in health and diseases.

dbGAPs: A comprehensive database of genes and genetic markers associated with psoriasis and its subtypes.

Psoriasis is a systemic hyperproliferative inflammatory skin disorder, although rarely fatal but significantly reduces quality of life. Understanding the full genetic component of the disease association may provide insight into biological pathways as well as targets and biomarkers for diagnosis, prognosis and therapy. Studies related to psoriasis associated genes and genetic markers are scattered and not easily amendable to data-mining. To alleviate difficulties, we have developed dbGAPs an integrated knowledgebase representing a gateway to psoriasis associated genomic data. The database contains annotation for 202 manually curated genes associated with psoriasis and its subtypes with cross-references. Functional enrichment of these genes, in context of Gene Ontology and pathways, provide insight into their important role in psoriasis etiology and pathogenesis. The dbGAPs interface is enriched with an interactive search engine for data retrieval along with unique customized tools for Single Nucleotide Polymorphism (SNP)/indel detection and SNP/indel annotations. dbGAPs is accessible at http://www.bmicnip.in/dbgaps/.

S9A Serine Protease Engender Antigenic Gluten Catabolic Competence to the Human Gut Microbe.

The human gut microbiome has a significant role in host physiology; however its role in gluten catabolism is debatable. Present study explores the role of human gut microbes in gluten catabolism and a native human gut microbe Cellulomonas sp. HM71 was identified. SSU rDNA analysis has described human gut microbiome structure and also confirmed the permanent residentship of Cellulomonas sp. HM71. Catabolic potential of Cellulomonas sp. HM71 to cleave antigenic gluten peptides indicates presence of candidate gene encoding biocatalytic machinery. Genome analysis has identified the presence of gene encoding S9A serine protease family-prolyl endopeptidase, with Ser591, Asp664 and His685 signature residues. Cellulomonas sp. HM71 prolyl endopeptidase activity was found optimal at pH 7.0 and 37 °C with a KM of 35.53 µmol and specifically cleaves at proline residue. Current study describes the gluten catabolism potential of Cellulomonas sp. HM71 depicting possible role of human gut microbes in gluten catabolism to confer resistance mechanisms for the onset of celiac diseases in populations with gluten diet.

Probing binding mechanism of interleukin-6 and olokizumab: in silico design of potential lead antibodies for autoimmune and inflammatory diseases.

Computer-aided antibody engineering has been successful in the design of new biologics for disease diagnosis and therapeutic interventions. Interleukin-6 (IL-6), a well-recognized drug target for various autoimmune and inflammatory diseases such as rheumatoid arthritis, multiple sclerosis, and psoriasis, was investigated in silico to design potential lead antibodies. Here, crystal structure of IL-6 along with monoclonal antibody olokizumab was explored to predict antigen-antibody (Ag - Ab)-interacting residues using DiscoTope, Paratome, and PyMOL. Tyr56, Tyr103 in heavy chain and Gly30, Ile31 in light chain of olokizumab were mutated with residues Ser, Thr, Tyr, Trp, and Phe. A set of 899 mutant macromolecules were designed, and binding affinity of these macromolecules to IL-6 was evaluated through Ag - Ab docking (ZDOCK, ClusPro, and Rosetta server), binding free-energy calculations using Molecular Mechanics/Poisson Boltzman Surface Area (MM/PBSA) method, and interaction energy estimation. In comparison to olokizumab, eight newly designed theoretical antibodies demonstrated better result in all assessments. Therefore, these newly designed macromolecules were proposed as potential lead antibodies to serve as a therapeutics option for IL-6-mediated diseases.