Emerging role of metabolomics for biomarker discovery in obstructive sleep apnea.

Obstructive sleep apnea (OSA) is characterized by the complete or partial blockage of the upper airway passage during sleep which causes repetitive breaks in sleep and may result in excessive daytime sleepiness. OSA has been linked to various metabolic disorders and chronic health conditions, such as obesity, diabetes, hypertension, and depression. Profiling of alterations in metabolites and their regulation in OSA has been hypothesized to be an effective approach for early diagnosis and prognosis of OSA. Several studies have characterized metabolic fingerprints associated with sleep disorders. There is a lack of understanding of metabolite contents and their alterations in OSA that may help to identify specific biomarkers. The information provided in this review will help update new methodologies and interventions of high throughput advanced molecular/metabolomics tools which may clarify the metabolic aspects and mechanisms for improved management and treatment of OSA.

Quantitative Analysis of Bioactive Carbazole Alkaloids in Murraya koenigii (L.) from Six Different Climatic Zones of India Using UPLC/MS/MS and Their Principal Component Analysis.

Murraya koenigii (L.) Spreng (Curry leaf) is a commercially important medicinal plant in South Asia, containing therapeutically valuable carbazole alkaloids (CAs). Thus, the quantitative evaluation of these compounds from different climatic zones of India are an important aspect for quality assessment and economic isolation of targeted compounds from the plant. In this study, quantitative estimation of CAs among 34 Indian natural populations of M. koenigii was assessed using UPLC/MS/MS. The collected populations represent the humid subtropical, tropical wet & dry, tropical wet, semi-arid, arid, and montane climatic zones of India. A total of 11 CAs viz. koenine-I, murrayamine A, koenigine, koenimbidine, koenimbine, O-methylmurrayamine A, girinimbine, mahanine, 8,8''-biskoenigine, isomahanimbine, and mahanimbine were quantified using multiple reaction monitoring (MRM) experiments within 5.0 min. The respective range for natural abundance of CAs were observed as 0.097-1.222, 0.092-5.014, 0.034-0.661, 0.010-1.673, 0.013-7.336, 0.010-0.310, 0.010-0.114, 0.049-5.288, 0.031-1.731, 0.491-3.791, and 0.492-5.399 mg/g in leaves of M. koenigii. The developed method shown linearity regression coefficient (r2 >0.9995), LOD (0.003-0.248 ng/mL), LOQ (0.009-0.754 ng/mL), and the recovery was between 88.803-103.729 %. The bulk of these CAs were recorded in their highest concentrations in the humid subtropical zone, followed by the tropical wet & dry zones of India. Further, principal component analysis (PCA) was performed which differentiated the climatic zones according to the dominant and significant CAs contents within the populations. The study concludes that the method established is simple, rapid, with high sample throughput, and can be used as a tool for commercial purposes and quality control of M. koenigii.

Rec A disruption unveils cross talk between DNA repair and membrane damage, efflux pump activity, biofilm formation in Mycobacterium smegmatis.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) has emerged in recent decades as one of the leading causes of mortality worldwide. The burden of TB is alarmingly high, with one third affected global population as reported by WHO. Short-course treatment with an antibiotic is a powerful weapon to treat infection of susceptible MTB strain, however; MTB has developed resistance to anti-TB drugs, which is an escalating global health crisis. Thus there is urgent need to identify new drug targets. RecA is a 38 kilodalton protein required for the repair and maintenance of DNA and regulation of the SOS response. The objective of this study is to understand the effect of disruption of RecA gene (deletion mutant ΔdisA from previous study) in a surrogate model for MTB, Mycobacterium smegmatis. This study demonstrated that disruption of RecA causes enhanced susceptibility towards rifampicin and generation of ROS leading to lipid peroxidation and impaired membrane homeostasis as depicted by altered cell membrane permeability and efflux pump activity. Mass spectrometry based lipidomic analysis revealed decreased mycolic acid moieties, phosphatidylinositol mannosides (PIM), Phthiocerol dimycocerosate (DIM). Furthermore, biofilm formation was considerably reduced. Additionally, we have validated all the disrupted phenotypes by RT-PCR which showed a good correlation with the biochemical assays. Lastly, RecA mutant displayed reduced infectivity in Caenorhabditis elegans illustrating its vulnerability as antimycobacterial target. Together, present study establishes a link between DNA repair, drug efflux and biofilm formation and validates RecA as an effective drug target. Intricate studies are needed to further understand and exploit this therapeutic opportunity.

Mechanistic insights into the antimycobacterial action of unani formulation, Qurs Sartan Kafoori.

Background and aim: Tuberculosis (TBC) is a deadly disease and major health issue in the world. Emergence of drug resistant strains further worsens the efficiency of available anti-TBC drugs. Natural compounds and particularly traditional medicines such as Unani drugs are one of the promising alternatives that have been widely used nowadays. This study aims to evaluate the efficacy of unani drug Qurs-e-Sartan Kafoori (QSK) on Mycobacterium tuberculosis (MTB). Experimental procedures: Drug susceptibilities were estimated by broth microdilution assay. Cell surface integrity was assessed by ZN staining, colony morphology and nitrocefin hydrolysis. Biofilms were visualized by crystal violet staining and measurement of metabolic activity and biomass. Lipidomics analysis was performed using mass spectrometry. Host pathogen interaction studies were accomplished using THP-1 cell lines to estimate cytokines by ELISA kit, apoptosis and ROS by flow cytometry. Results: QSK enhanced the susceptibilities of isoniazid and rifampicin and impaired membrane homeostasis as depicted by altered cell surface properties and enhanced membrane permeability. In addition, virulence factor, biofilm formation was considerably reduced in presence of QSK. Lipidomic analysis revealed extensive lipid remodeling. Furthermore, we used a THP-1 cell line model, and investigated the immunomodulatory effect by estimating cytokine profile and found change in expressions of TNF-α, IL-6 and IL-10. Additionally, we uncover reduced THP-1 apoptosis and enhanced ROS production in presence of QSK. Conclusion: Together, this study validates the potential of unani formulation (QSK) with its mechanism of action and attempts to highlight its significance in MDR reversal.

Understanding Mass Spectrometry-based Global Mycobacterial Lipidomics.

Tuberculosis (TB) is the foremost cause of mortality from single infectious agent Mycobacterium tuberculosis (MTB). Current therapeutic regimes suffer from several problems, including side effects, costs and emergence of multidrug resistance (MDR). Moreover, conventional diagnostic methods are either too slow, or lack accurate and robust biomarkers. Under such circumstances, identification of rapid metabolite based biomarkers as novel drug targets could be a potential approach to circumvent MDR. In the era of "OMIC" sciences, lipidomics has gained significant attention to unravel the complexity of lipid-loaded Mycobacterium species. Lipidomics is a subbranch of metabolomics with extreme atomic diversity between the metabolites. There is no single principle on which the metabolite diversity can be defined, unlike other biomolecules viz. nucleic acid, proteins or carbohydrates. MTB encodes 10% of the genome for lipid metabolism and lipids account for 60% of its dry weight. Mycobacterium harbor a wide spectra of lipid repertoire ranging from highly apolar to highly polar lipids, adding complexity to their identification and analysis. Compared to targeted approaches, untargeted or global lipidomics of MTB is still more challenging. This review describes recent advances in lipidomics technology with regard to chromatography, detection methods and assessment on the existing mass spectrometry-based lipidomics tools to study the untargeted or global MTB lipidomics. It also identifies the limitations associated with present technologies as well as explores solutions to practical challenges concurrent with the establishment of MTB lipidome. Together we endorse that the emerging tools of lipidomics have provided a broader vision to comprehend the role of lipid molecules in MTB pathogenesis and the need for further improvements.

A Localized Chimeric Hydrogel Therapy Combats Tumor Progression through Alteration of Sphingolipid Metabolism.

Rapid proliferation of cancer cells assisted by endothelial cell-mediated angiogenesis and acquired inflammation at the tumor microenvironment (TME) lowers the success rate of chemotherapeutic regimens. Therefore, targeting these processes using localized delivery of a minimally toxic drug combination may be a promising strategy. Here, we present engineering of a biocompatible self-assembled lithocholic acid-dipeptide derived hydrogel (TRI-Gel) that can maintain sustained delivery of antiproliferating doxorubicin, antiangiogenic combretastatin-A4 and anti-inflammatory dexamethasone. Application of TRI-Gel therapy to a murine tumor model promotes enhanced apoptosis with a concurrent reduction in angiogenesis and inflammation, leading to effective abrogation of tumor proliferation and increased median survival with reduced drug resistance. In-depth RNA-sequencing analysis showed that TRI-Gel therapy induced transcriptome-wide alternative splicing of many genes responsible for oncogenic transformation including sphingolipid genes. We demonstrate that TRI-Gel therapy targets the reversal of a unique intron retention event in ß-glucocerebrosidase 1 (Gba1), thereby increasing the availability of functional Gba1 protein. An enhanced Gba1 activity elevates ceramide levels responsible for apoptosis and decreases glucosylceramides to overcome drug resistance. Therefore, TRI-Gel therapy provides a unique system that affects the TME via post-transcriptional modulations of sphingolipid metabolic genes, thereby opening a new and rational approach to cancer therapy.

Ethyl acetate fraction of Eclipta alba: a potential phytopharmaceutical targeting adipocyte differentiation.

Natural products have always fascinated mankind for their miraculous properties. Eclipta alba (E. alba), a medicinal herb has long been used in traditional medicine for curing several pathologies. It has been shown to have anti-diabetic effect as well as hepato-protective activity. Here, in order to address metabolic derangements, the study was designed to evaluate the efficacy of E. alba and its fractions in adipogenesis inhibition and dyslipidemia. Of the crude extract and fractions screened, ethyl acetate fraction of E. alba inhibited adipocyte differentiation in 3T3-L1 pre-adipocytes and hMSC derived adipocytes. It inhibited mitotic clonal expansion and caused cell cycle arrest in G1 and S phase as suggested by western blot analysis and flow cytometry. It was also shown to have lipolytic effects. Oral administration of ethyl acetate fraction of E. alba to hamsters unveiled its anti-adipogenic as well as anti-dyslipidemic activity in-vivo. Mass spectrometry analysis of ethyl acetate fraction confirmed the presence of several bioactive components, projecting it as an effective phytopharmaceutical agent. In conclusion, ethyl acetate fraction of E. alba possesses potent anti-adipogenic as well as anti-dyslipidemic activity and could be projected as an herbal formulation towards obesity.