Prioritization before dereplication, an effective strategy to target new metabolites in whole extracts: ghosalin from Murraya paniculata root.

Re-discovery of known metabolites is a common challenge in natural product-based drug discovery, and to avoid re-discovery, dereplication has been proposed for identifying known metabolites at the early stage of isolation. A majority of methods use LCMS to profile the extract and ignore the known mass. LC-HRMS profiling may generate a long mass list of metabolites. The identification of a new metabolite is difficult within the mass list. To overcome this, it was hypothesized that identifying a 'new metabolite' in the whole metabolome is more difficult than identifying it within the class of metabolites. A prioritization strategy was proposed to focus on the elimination of unknown and uncommon metabolites first using the designed bias filters and to prioritize the known secondary metabolites. The study employed Murraya paniculata root for the identification of new metabolites. The LC-HRMS-generated mass list of 509 metabolites was subjected to various filters, which resulted in 93 metabolites. Subsequently, it was subjected to regular dereplication, resulting in 10 coumarins, among which 3 were identified as new. Further, chromatographic efforts led to the isolation of a new coumarin, named ghosalin (1). The structure of the new compound was established through 2D NMR and X-ray crystallography. Cytotoxicity studies revealed that ghosalin has significant cytotoxicity against cancer cell lines. The proposed prioritization strategy demonstrates an alternative way for the rapid annotation of a particular set of metabolites to isolate a new metabolite from the whole metabolome of a plant extract.

Exploring the cytotoxic potential of biflavones of Araucaria cunninghamii: Precise identification combined by LC-HRMS-metabolomics and database mining, targeted isolation, network pharmacology, in vitro cytotoxicity, and docking studies.

The leaves of Araucaria cunninghamii are known to be nonedible and toxic. Previous studies have identified biflavones in various Araucaria species. This study aimed to investigate the in vitro cytotoxicity of the isolated compounds from Araucaria cunninghamii after metabolomics and network pharmacological analysis. Methanol extract of Araucaria cunninghamii leaves was subjected to bioassay-guided fractionation. The active fraction was analyzed using LC-HRMS, through strategic database mining, by comparing the data to the Dictionary of Natural Products to identify 12 biflavones, along with abietic acid, beta-sitosterol, and phthalate. Eight compounds were screened for network pharmacology study, where in silico ADME analysis, prediction of gene targets, compound-gene-pathway network and hierarchical network analysis, protein-protein interaction, KEGG pathway, and Gene Ontology analyses were done, that showed PI3KR1, EGFR, GSK3B, and ABCB1 as the common targets for all the compounds that may act in the gastric cancer pathway. Simultaneously, four biflavones were isolated via chromatography and identified through NMR as dimeric apigenin with varying methoxy substitutions. Cytotoxicity study against the AGS cell line for gastric cancer showed that AC1 biflavone (IC50 90.58 µM) exhibits the highest cytotoxicity and monomeric apigenin (IC50 174.5 µM) the lowest. Besides, the biflavones were docked to the previously identified targets to analyze their binding affinities, and all the ligands were found to bind with energy ≤-7 Kcal/mol.

New ring-A modified cycloartane triterpenoids from Dysoxylum malabaricum bark: Isolation, structure elucidation and their cytotoxicity.

The Genus Dysoxylum (Meliaceae) consists of approximately 80 species that are abundant in structurally diverse triterpenoids. The present study focused on isolating new triterpenoids from the bark of Dysoxylum malabaricum, one of the predominant species of Dysoxylum present in India. The methanol-dichloromethane bark extract was subjected to LCMS profiling followed by silica gel column chromatography and HPLC analysis to target new compounds. Two new ring A-modified cycloartane-type triterpenoids (1 and 2) were isolated from the bark extract. Spectroscopic methods like NMR, HRESIMS data, and electronic circular dichroism calculations elucidated the structuresandabsolute configurations of the isolated compounds. These compounds were evaluated for their cytotoxic potential against breast cancer cells and displayed notable cytotoxicity. Compound 1 exhibited the highest cytotoxicity against the MDA-MB-231 cells and induced apoptotic cell death. Also, it was able to inhibit glucose uptake and increase nitric oxide production in breast cancer cells.

Culture and transfection: Two major bottlenecks in understanding Plasmodium vivax biology.

The long term in vitro culture of Plasmodium falciparum was successfully established by Trager and Jensen in 1976; however it largely remains unachieved for P. vivax. The major obstacle associated with Plasmodium vivax in vitro culture is its predilection for invading younger reticulocytes and the complex remodelling of invaded reticulocytes. There are many factors under exploration for this predilection and host-parasite interactions between merozoites and invaded reticulocytes. These include various factors related to parasite, host and environment such as compromised reticulocyte osmotic stability after invasion, abundance of iron in the reticulocytes which makes them favourable for P. vivax growth and propagation and role of a hypoxic environment in P. vivax in vitro growth. P. vivax blood stage transfection represents another major hurdle towards understanding this parasite's complex biology. Efforts in making this parasite amenable for molecular investigation by genetic modification are limited. Newer approaches in sustaining a longer in vitro culture and thereby help advancing transfection technologies in P. vivax are urgently needed that can be explored to understand the unique biology of this parasite.

Diagnostic Accuracy of a Nurse-Led Transient Elastography: A Study of a Tertiary Hospital Experience.

Once thought rare, liver disease is an emerging cause of significant morbidity and mortality. The rising burden of liver disease necessitates a competent workforce to deliver quality healthcare to patients with liver diseases. Staging liver diseases is essential in disease management. Transient elastography as compared with liver biopsy, the gold standard in staging of the disease, has gained wide acceptance in this field. This study examines the diagnostic accuracy of nurse-led transient elastography in staging fibrosis in chronic liver diseases at a tertiary referral hospital. Audit of records to locate transient elastography and liver biopsy performed within 6 months of interval yielded 193 cases for this retrospective study. A data abstraction sheet was prepared for extracting the relevant data. The content validity index and reliability of the scale were above 0.9. The diagnostic accuracy of liver stiffness evaluation (in kPa) by nurse-led transient elastography to grade fibrosis was categorized as "significant and advanced" and tested against the Ishak staging of liver biopsy. SPSS v.25 was used to perform the analysis. All tests were two-sided at a .01 level of significance. Area under the receiver operating characteristic curve, a graphical plot, illustrated the diagnostic ability of nurse-led transient elastography for significant fibrosis as 0.93 (95% confidence interval [CI] 0.88-0.99; p < .001) and advanced fibrosis as 0.89 (95% CI 0.83-0.93; p < .001). Spearman's ρ correlation between liver stiffness evaluation and liver biopsy was significant ( p = .01). Nurse-led transient elastography showed a significant diagnostic accuracy in staging hepatic fibrosis irrespective of the etiology of chronic liver disease. Given the increase in chronic liver disease, introducing more such nurse-led clinics increases the potential for early detection and improves care outcomes for this population.

Therapeutic effects of oral fluralaner in pet rabbits with severe sarcoptic mange (Sarcoptes scabiei).

Sarcoptic mange is one of the most severe, highly contagious, and fatal ectoparasitic infestations of rabbits. Fluralaner, an isoxazoline class of oral ectoparasiticide, is considered as a very potent acaricide. The present study aimed to evaluate the therapeutic efficacy of oral fluralaner in pet rabbits with severe spontaneous Sarcoptes scabiei infestation. A total of eight un-neutered pet rabbits, tested positive for S. scabiei by microscopy of skin scrapings, were enrolled. Seven rabbits had severe clinical infestation (score 5), while remaining one rabbit had moderate disease clinical signs (score <3). A single oral dose equivalent to 25 mg/kg of fluralaner was administered to each rabbit. On day 14 post-therapy, marked improvements in the skin lesions were observed; severely infested rabbits had a clinical score of 3, while the moderately infested rabbit had a score of 1. However, none of the rabbits tested negative for S. scabiei. On day 30 post-therapy, complete clinical recovery was recorded in all rabbits (Score 0), but, a complete parasitological clearance was not recorded except to the moderately infested rabbit. All rabbits were tested negative for S. scabiei on day 45 post-therapy. Therefore, a single oral dose of fluralaner at a 25 mg/kg was found to be effective in the treatment of severe sarcoptic mange in pet rabbits and no additional topical or systemic medications were needed. Further studies in a larger number of individuals with a bigger spectrum of disease severities (i.e. more moderate/mild) are needed to comprehensively document the safety and efficacy of this drug in mangy rabbits.

Development of Euphorbia Latex and Bamboo Fiber Based Green Composite.

Novel composites with improved mechanical strength, thermally stability and better biodegradability were fabricated using polyester resin (PR) and euphorbia coagulum (EC) with natural bamboo fiber (BF) by a compression molding technique. The addition of EC makes the composite more pronounced for alkali-treated BF. The composites were characterized in terms of water absorption, mechanical, thermal and biodegradability. Composites showed considerable improvement in thermal stability, mechanical properties (flexural strength and impact strength) and biodegradability. EC modified composite shows maximum improvement in physico-mechanical properties compared to other composites. The inoculation of EC modified and unmodified composite with fungi resulted in higher growth on modified composite compared to unmodified composite. These novel composites could be labeled as sustainable material because they were prepared from low-cost BF and EC through a green approach. The composite material developed can be used in building constructions as wood substitution, automotive parts, sports goods, etc.

Dopamine promotes cathepsin B-mediated amyloid precursor protein degradation by reactive oxygen species-sensitive mechanism in neuronal cell.

Recent literature suggested an important function of native amyloid precursor protein (APP) as amine oxidase implicating in protection of brain cells from catecholamine-induced toxicity. However, any role of catecholamines on regulation of native APP has not been explored. Here we report that dopamine (DA), one of the most prominent catecholamine neurotransmitters in brain, down-modulates native APP protein in several neuronal cell types. Using SH-SY5Y cells as model, we detected no alteration of transcript expression and unaffected translation suggested that DA might induce APP degradation. We actually found that DA treatment decreased the stability of APP. Lysosomal blockers inhibited DA-induced APP degradation, but specific proteasomal blocker failed to do so. We detected the role of cathepsin B in DA-induced APP degradation by using pharmacological inhibitor and specific siRNA. We also revealed that DA could increase cathepsin B expression at both transcript and protein levels. Using antioxidant N-acetyl cysteine, we detected increased level of reactive oxygen species generation that was found responsible for induced cathepsin B expression by DA and resultant APP degradation. Our study reveals the existence of reciprocal regulation of a catecholamine and an amine oxidase implicating in brain catecholamine homeostasis.

Vestibular Incision Subperiosteal Tunnel Access with Titanium-Prepared Platelet-Rich Fibrin - A Golden Approach for Treating Multiple Recession Defects in Esthetic Zone.

Gingival recession is defined as apical migration of marginal gingival tissue causing the exposure of root surface. Abnormal brushing techniques, trauma, anatomical presence of tooth, caries, and improper oral hygiene measures are some of the problems leading to gingival recession. Several treatment modalities such as coronary advanced flaps and free gingival grafts have been used for the treatment of gingival recession defects and showed good results. However, while treating multiple gingival recessions, some new treatment modalities were introduced in literature. Vestibular incision subperiosteal tunnel access (VISTA) as a minimally invasive technique for root coverage was introduced with various advantages such as no secondary surgical site needed for harvestment of donor tissue and it provides excellent esthetic results with decreased patient morbidity. The present case report emphasizes on the treatment of multiple gingival recessions in the maxillary anterior teeth region using VISTA with titanium-prepared platelet-rich fibrin.

Leishmania donovani inhibits ferroportin translation by modulating FBXL5-IRP2 axis for its growth within host macrophages.

Hepcidin mediated ferroportin (Fpn) degradation in macrophages is a well adopted strategy to limit iron availability towards invading pathogens. Leishmania donovani (LD), a protozoan parasite, resides within macrophage and competes with host for availing iron. Using in vitro and in vivo model of infection, we reveal that LD decreases Fpn abundance in host macrophages by hepcidin independent mechanism. Unaffected level of Fpn-FLAG in LD infected J774 macrophage confirms that Fpn down-regulation is not due its degradation. While increased Fpn mRNA but decreased protein expression in macrophages suggests blocking of Fpn translation by LD infection that is confirmed by 35 S-methionine labelling assay. We further reveal that LD blocks Fpn translation by induced binding of iron regulatory proteins (IRPs) to the iron responsive element present in its 5'UTR. Supershift analysis provides evidence of involvement of IRP2 particularly during in vivo infection. Accordingly, a significant increase in IRP2 protein expression with simultaneous decrease in its stability regulator F-box and leucine-rich repeat Protein 5 (FBXL5) is detected in splenocytes of LD-infected mice. Increased intracellular growth due to compromised expressions of Fpn and FBXL5 by specific siRNAs reveals that LD uses a novel strategy of manipulating IRP2-FBXL5 axis to inhibit host Fpn expression.

An in vitro study ascertaining the role of H2O2 and glucose oxidase in modulation of antioxidant potential and cancer cell survival mechanisms in glioblastoma U-87 MG cells.

Glial cells protect themselves from the elevated reactive oxygen species (ROS) via developing unusual mechanisms to maintain the genomic stability, and reprogramming of the cellular antioxidant system to cope with the adverse effects. In the present study non-cytotoxic dose of oxidants, H2O2 (100 µM) and GO (10 µU/ml) was used to induce moderate oxidative stress via generating ROS in human glioblastoma cell line U-87 MG cells, which showed a marked increase in the antioxidant capacity as studied by measuring the modulation in expression levels and activities of superoxide dismutase (SOD1 and SOD2) and catalase (CAT) enzymes, and the GSH content. However, pretreatment (3 h) of Curcumin and Quercetin (10 µM) followed by the treatment of oxidants enhanced the cell survival, and the levels/activities of the antioxidants studied. Oxidative stress also resulted in an increase in the nitrite levels in the culture supernatants, and further analysis by immunocytochemistry showed an increase in iNOS expression. In addition, phytochemical pretreatment decreased the nitrite level in the culture supernatants of oxidatively stressed U-87 MG cells. Elevated ROS also increased the expression of COX-2 and APE1 enzymes and pretreatment of Curcumin and Quercetin decreased COX-2 expression and increased APE1 expression in the oxidatively stressed U-87 MG cells. The immunocytochemistry also indicates for APE1 enhanced stress-dependent subcellular localization to the nuclear compartment, which advocates for enhanced DNA repair and redox functions of APE1 towards survival of U-87 MG cells. It can be concluded that intracellular oxidants activate the key enzymes involved in antioxidant mechanisms, NO-dependent survival mechanisms, and also in the DNA repair pathways for glial cell survival in oxidative-stress micro-environment.

Role of extracellular Hydrogen peroxide in regulation of iron homeostasis genes in neuronal cells: Implication in iron accumulation.

Iron accumulation and oxidative stress are associated with neurodegenerative disease. Labile iron is known to catalyze free radical generation and subsequent neuronal damage, whereas the role of oxidative stress in neuronal iron accumulation is less well understood. Here, we examined the effect of hydrogen peroxide (H2O2) treatment on cellular iron-uptake, -storage, and -release proteins in the neuroblastoma cell line SH-SY5Y. We found no detectable change in the iron-uptake proteins transferrin receptor-1 and divalent metal ion transporter. In contrast, H2O2 treatment resulted in significant degradation of the iron-exporter ferroportin (Fpn). A decrease in Fpn is expected to increase the labile iron pool (LIP), reducing the iron-regulatory protein (IRP)-iron-responsive element interaction and increasing the expression of ferritin-H (Ft-H) for iron storage. Instead, we detected IRP1 activation, presumably due to oxidative stress, and a decrease in Ft-H translation. A reduction in Ft-H mRNA was also observed, probably dependent on an antioxidant-response element present in the Ft-H enhancer. The decrease in Fpn and Ft-H upon H2O2 treatment led to a time-dependent increase in the cellular LIP. Our study reveals a complex regulation of neuronal iron-release and iron-storage components in response to H2O2 that may explain iron accumulation detected in neurodegenerative diseases associated with oxidative stress.

Screening of IR50 x Rathu Heenati F7 RILs and identification of SSR markers linked to brown planthopper (Nilaparvata lugens Stål) resistance in rice (Oryza sativa L.).

Brown planthopper (Nilaparvata lugens Stål) is one of the major insect pests of rice. A Sri Lankan indica rice cultivar Rathu Heenati was found to be resistant to all biotypes of the brown planthopper. In the present study, a total of 268 F(7) RILs of IR50 and Rathu Heenati were phenotyped for their level of resistance against BPH by the standard seedbox screening test (SSST) in the greenhouse. A total of 53 SSR primers mapped on the chromosome 3 were used to screen the polymorphism between the parents IR50 and Rathu Heenati, out of which eleven were found to be polymorphic between IR50 and Rathu Heenati. The eleven primers that have shown polymorphism between the IR50 and Rathu Heenati parents were genotyped in a set of five resistant RILs and five susceptible RILs along with the parents for co-segregation analysis. Among the eleven primers, two primers namely RM3180 (18.22 Mb) and RM2453 (20.19 Mb) showed complete co-segregation with resistance. The identification of SSR markers linked with BPH resistant could be used for the maker assisted selection (MAS) program in rice breeding and to map the resistant genes on rice chromosomes for further gene cloning.