Bioactive Research Articles

Unlocking Biological Activity and Metabolomics Insights: Primary Screening of Cyanobacterial Biomass from a Tropical Reservoir.

Cyanobacterial harmful algal blooms can pose risks to ecosystems and human health worldwide due to their capacity to produce natural toxins. The potential dangers associated with numerous metabolites produced by cyanobacteria remain unknown. Only select classes of cyanopeptides have been extensively studied with the aim of yielding substantial evidence regarding their toxicity, resulting in their inclusion in risk management and water quality regulations. Information about exposure concentrations, co-occurrence, and toxic impacts of several cyanopeptides remains largely unexplored. We used liquid chromatography-mass spectrometry (LC-MS)-based metabolomic methods associated with chemometric tools (NP Analyst and Data Fusion-based Discovery), as well as an acute toxicity essay, in an innovative approach to evaluate the association of spectral signatures and biological activity from natural cyanobacterial biomass collected in a eutrophic reservoir in southeastern Brazil. Four classes of cyanopeptides were revealed through metabolomics: microcystins, microginins, aeruginosins, and cyanopeptolins. The bioinformatics tools showed high bioactivity correlation scores for compounds of the cyanopeptolin class (0.54), in addition to microcystins (0.54-0.58). These results emphasize the pressing need for a comprehensive evaluation of the (eco)toxicological risks associated with different cyanopeptides, considering their potential for exposure. Our study also demonstrated that the combined use of LC-MS/MS-based metabolomics and chemometric techniques for ecotoxicological research can offer a time-efficient strategy for mapping compounds with potential toxicological risk. Environ Toxicol Chem 2024;00:1-10. © 2024 SETAC.

Expression, Sarkosyl Solubilization, DNase Activity, Purification, and SPR Binding Affinity of Recombinant Diphtheria Toxoid (rCRM197EK) Expressed in Escherichia coli BL21(DE3).

CRM197EK is a derivative of diphtheria toxoid cross-reactive material-197 (CRM197) with two-point mutations (K51E and E148K) to improve its properties for a vaccine conjugate and drug delivery. A previous study has shown that intracellularly expressing CRM197EK in Escherichia coli (E. coli) host formed inclusion bodies that need a complicated purification and refolding step. Protein purification from inclusion bodies can be overcome by solubilization of inclusion bodies by using N-lauroyl sarcosine (sarkosyl). In this work, recombinant CRM197EK (rCRM197EK) was expressed in E. coli BL21 (DE3) as inclusion bodies, then solubilized using sarkosyl to form a soluble rCRM197EK without the need for a renaturation process. Furthermore, rCRM197EK was purified using the Ni-NTA column, characterized by SDS-PAGE and Western Blot, and its biological activity was assayed through its DNase activity. Moreover, its binding affinity with anti-diphtheria toxin (DT) antibody was measured using the surface plasmon resonance (SPR). The result showed that solubilization with sarkosyl form soluble rCRM197EK (61.61kDa) was confirmed by SDS-PAGE and Western Blot with a yield of 2.8mg/mL. rCRM197EK shows DNase activity, and the SPR assay shows that it can interact with an anti-DT antibody with a binding energy of - 9.2kcal/mol.

Active learning approaches in molecule pKi prediction.

During the early stages of drug design, identifying compounds with suitable bioactivities is crucial. Given the vast array of potential drug databases, it's feasible to assay only a limited subset of candidates. The optimal method for selecting the candidates, aiming to minimize the overall number of assays, involves an active learning (AL) approach. In this work, we benchmarked a range of AL strategies with two main objectives: (1) to identify a strategy that ensures high model performance and (2) to select molecules with desired properties using minimal assays. To evaluate the different AL strategies, we employed the simulated AL workflow based on "virtual" experiments. These experiments leveraged ChEMBL datasets, which come with known biological activity values for the molecules. Furthermore, for classification tasks, we proposed the hybrid selection strategy that unified both exploration and exploitation AL strategies into a single acquisition function, defined by parameters n and c. We have also shown that popular minimal margin and maximal variance selection approaches for exploration selection correspond to minimization of the hybrid acquisition function with n=1 and 2 respectively. The balance between the exploration and exploitation strategies can be adjusted using a coefficient (c), making the optimal strategy selection straightforward. The primary strength of the hybrid selection method lies in its adaptability; it offers the flexibility to adjust the criteria for molecule selection based on the specific task by modifying the value of the contribution coefficient. Our analysis revealed that, in regression tasks, AL strategies didn't succeed at ensuring high model performance, however, they were successful in selecting molecules with desired properties using minimal number of tests. In analogous experiments in classification tasks, exploration strategy and the hybrid selection function with a constant c<1 (for n=1) and c≤0.2 (for n=2) were effective in achieving the goal of constructing a high-performance predictive model using minimal data. When searching for molecules with desired properties, exploitation, and the hybrid function with c≥1 (n=1) and c≥0.7 (n=2) demonstrated efficiency identifying molecules in fewer iterations compared to random selection method. Notably, when the hybrid function was set to an intermediate coefficient value (c=0.7), it successfully addressed both tasks simultaneously.

Synthesis and biological evaluation of imidazolium conjugated with dimethylcardamonin (DMC) as a novel potential agent against MDA-MB-231 triple-negative breast cancer cells

A new imidazolium ionic liquid (IL) halide conjugated with dimethylcardamonin (DMC, 1), namely [Bbim]Br-DMC (3), was synthesised to improve the biological activity of the natural chalcone. DMC was isolated from seeds of Syzygium nervosum A. Cunn. ex DC. which was an effective anti-breast cancer agent. The compound 1 and 3 showed anticancer activity in MDA-MB-231 cells with IC50 values of 14.54 ± 0.99 μM and 7.40 ± 0.15 μM, respectively. MTT assay showed that compound 3 had cytotoxic effect at least two-fold greater than compound 1 but was low toxic to normal cells of Hs 578Bst. After 48 h, compound 3 at concentration of IC50 value inhibited the proliferation and induced morphological changes of MDA-MB-231 cells in a time-dependent manner. The cell cycle profile also showed that compound 3 exerted anti-proliferation activity with the cell cycle arrest at G0/G1 phase and compound 3 also induced apoptosis and reduced mitochondrial membrane potential in MDA-MB-231 cells in a dose-dependent manner. In gene expression assay, compound 3 up-regulated pro-apoptotic genes such as Bax and p53 and suppressed anti-apoptotic Bcl-2 whereas there was no effect on DNA repair gene such as PARP1. The Bax/Bcl-2 ratio was significantly increased after treated with compound 3. In the molecular docking study, the interactions between compound 3 and B-DNA structure in the minor groove region via hydrogen bonds was reported. In conclusion, [Bbim]Br-DMC or compound 3 is a potential candidate to induce apoptosis and inhibits proliferation via cell cycle arrest and decreases mitochondrial membrane of triple-negative breast cancer MDA-MB-231 cells.

An overview of pyridazin-3(2H)-one: a core for developing bioactive agents targeting cardiovascular diseases and cancer.

Cardiovascular diseases (CVDs) and cancer are the top two leading causes of death globally. Vasodilators are commonly used to treat various CVDs. In cancer treatment, targeted anticancer agents have been developed to minimize side effects compared with traditional chemotherapy. Many hypertension patients are more prone to cancer, a case known as reverse cardio-oncology. This leads to the search for drugs with dual activity or repurposing strategy to discover new therapeutic uses for known drugs. Recently, medicinal chemists have shown great interest in synthesizing pyridazinone derivatives due to their significant biological activities in tackling these critical health challenges. This review will concentrate on pyridazin-3(2H)-one-containing compounds as vasodilators and anticancer agents, along with a brief overview of various methods for their synthesis.

Scaffold Hopping of Pristimerin Provides Derivatives Containing a Privileged Quinoxaline Substructure as Potent Autophagy Inducers in Breast Cancer Cells.

Pristimerin is a natural triterpenoid that has received much attention from medicinal chemists for its multiple biological activities. However, structural modifications of pristimerin, especially those aimed at discovering antitumor agents, are relatively limited. In this study, two series of pristimerin derivatives containing phenyloxazole and quinoxaline moieties, respectively, were designed via the scaffold hopping strategy. The target compounds were synthesized and analyzed for their cytotoxic activities in vitro using the MTT assay. The most potent cytotoxic compound (21o) significantly inhibited the proliferation of MCF-7 cells with an IC50 value of 2.0 μM, 1.5-fold more potent than pristimerin (IC50 = 3.0 μM). Compared with pristimerin, compound 21o displayed the greatest improvement in selectivity (25.7-fold) against the MCF-7 and MCF-10A cell lines. Transmission electron microscopy, monodansylcadaverine and DCFH-DA staining, Western blotting, and different inhibitor assays were performed to elucidate the mechanism of action of compound 21o. Compound 21o induced autophagy-mediated cell death in MCF-7 cells by activating the ROS/JNK signaling pathway. Therefore, incorporating a quinoxaline substructure into pristimerin could be advantageous for enhancing its cytotoxic activity. Compound 21o may serve as a lead compound for developing new therapies to treat breast cancer.

An Integrated Module Performs Selective 'On-Line' Epoxidation in the Biosynthesis of the Antibiotic Mupirocin.

The delineation of the complex biosynthesis of the potent antibiotic mupirocin, which consists of a mixture of pseudomonic acids (PAs) isolated from Pseudomonas fluorescens NCIMB 10586, presents significant challenges and the timing and mechanisms of several key transformations remain elusive.Particularly intriguing are the steps that process the linear backbone from the initial polyketide assembly phase to generate the first cyclic intermediate PA-B. These include epoxidation as well as incorporation of the tetrahydropyran (THP) ring and fatty acid sidechain required for biological activity. Here, we show that the mini-module MmpE performs a rare online (ACP-substrate) epoxidation and is integrated ('in-cis') into the polyketide synthase via a docking domain. A linear polyketide fragment with 6 asymmetric centres was synthesised using a convergent approach and used to demonstrate substrate flux via an atypical KS0and a previously unannotated ACP (MmpE_ACP). MmpE_ACP-bound synthetic substrates were critical in demonstrating successful epoxidation in vitro by the purified MmpE oxidoreductase domain. Alongside feeding studies, these results confirm the timing as well as chain length dependence of this selective epoxidation. These mechanistic studies pinpoint the location and nature of the polyketide substrate prior to the key formation of the THP ring and esterification that generate PA-B.

Biocide-encapsulated core–shell polymer microspheres: A novel approach for preparing long-lasting antimicrobial coatings

Antimicrobial coatings play a crucial role in combating pathogenic microorganisms. However, developing long-lasting antimicrobial coatings presents substantial challenges. In this study, we developed a robust method for fabricating durable antimicrobial coatings using crosslinked, biocide-encapsulated core–shell polymer microspheres. These microspheres were prepared by emulsion polymerization, facilitating simultaneous synthesis and biocide loading. Designed with a hydrophilic shell and a hydrophobic core, the microspheres predominantly stored the hydrophobic biocides within the core, thus reducing the biocide concentration at the shell. This design, which is governed by Fickian diffusion, substantially slowed the rate of biocide migration from the shell to the external environment, thereby enhancing the coating's antimicrobial longevity. The synthetic process for these biocide-encapsulated microspheres was optimized to encapsulate biocides with a Log P range of 1–3, achieving an encapsulation efficiency exceeding 85 % for all tested biocides. Specifically, microspheres containing N-butyl-1,2-benzisothiazolin-3-one (BBIT) were used to develop an antimicrobial coating. The coating can be applied to various substrates, including glass, metal, wood, ceramics, and plastics. It exhibits excellent hardness, adhesion, mechanical strength, and solvent resistance on these surfaces. Antimicrobial tests and release analyses demonstrated that the coating maintains high biological activity for at least 10 months, effectively inhibiting bacterial and fungal growth. The release behavior of the coating adhered to the Peppas–Sahlin model, with diffusion as the predominant mechanism. The model predicted an antimicrobial retention rate of over 66 % after 1 year, confirming its sustained antimicrobial effectiveness.

Isoquercitrin attenuates neuroinflammation in LPS-stimulated BV2 microglia cells via p38MAPK/NF-κB pathway

Abstract Objectives Microglia mediated neuronal inflammation has been reported to be responsible for neurodegenerative disease. Isoquercitrin (IQC), widely found in fruits, vegetables and foods, has high bioavailability and offers many benefits of humans. Although IQC has been shown to possess pleiotropic biological activities, but its anti-inflammatory mechanism in microglia at molecular level remains largely unclear. Therefore, this study aimed to investigate IQC’s inhibition on inflammation within BV2 microglia cells induced by lipopolysaccharide (LPS) and the underlying mechanism. Methods The cell viability was tested by using the MTT assay and the No production was measured by Griess reagent. Inflammatory cytokines expression was determined by RT-qPCR and the expression of iNOS、COX2 and correlation factor of NF-κB and MAPK pathway were determined by RT-qPCR and western blotting. Results IQC does not affect the viability of LPS-stimulated microglia. IQC treatment inhibited LPS-triggered NO and PGE2 production, iNOS and COX2 expression and affected the mRNA levels of relative inflammatory cytokines. Moreover, IQC inhibited nuclear factor kappa B(NF-κB) and MAPK pathway activation mediated by LPS, thereby inhibiting the levels of inflammatory cytokines. Conclusions IQC exhibited remarkable anti-inflammatory effects and promised therapeutic potential for neural inflammation associated diseases.

Biological Evaluation of Dinuclear Platinum(II) Complexes with Aromatic N-Heterocycles as Bridging Ligands

The history of effective anti-cancer medications begins with the discovery of cisplatin’s anti-cancer properties. Second-generation analogue, carboplatin, with a similar range of effectiveness, made progress in improving these drugs with fewer side effects and better solubility. Renewed interest in platinum-based drugs has been increasing in the past several years. These developments highlight a revitalized enthusiasm and ongoing exploration in platinum chemotherapy based on the series of dinuclear platinum(II) complexes, [{Pt(L)Cl}2(μ-bridging ligand)]2+, which have been synthesized and evaluated for their biological activities. These complexes are designed to target various cancerous conditions, exhibiting promising antitumor, antiproliferative, and apoptosis-inducing activities. The current work aims to shed light on the potential of these complexes as next-generation platinum-based therapies, highlighting their enhanced efficacy and reduced side effects, which could revolutionize the approach to chemotherapy.

Attenuation of Quorum Sensing Mediated Virulence Factors and Biofilm Formation in Pseudomonas Aeruginosa PAO1 by Substituted Chalcones and Flavonols.

Flavonoids epitomize structural scaffolds in many biologically active synthetic and natural compounds. They showcase a diverse spectrum of biological activities including anticancer, antidiabetic, antituberculosis, antimalarial, and antibiofilm activities. The antibiofilm activity of a series of new chalcones and flavonols against clinically significant Pseudomonas aeruginosa PAO1 strain was studied. Antivirulence activities were screened by analysing the effect of compounds on the production of virulence factors like pyocyanin, LasA protease, cell surface hydrophobicity, and rhamnolipid. The best ligands towards the quorum sensing proteins LasR, RhlR, and PqsR were recognised using a molecular docking study. The gene expression in P. aeruginosa after treatment with test compounds was evaluated on quorum sensing genes including rhlA, lasB, and pqsE. The antibiofilm potential of chalcones and flavonols was confirmed by the efficient reduction in the production of virulence factors and downregulation of gene expression.

The interplay between doxorubicin chemotherapy, antioxidant system, and cardiotoxicity: Unrevealing of the protective potential of tannic acid.

Cardiotoxicity is the leading side effect of anthracycline-based chemotherapy. Therefore, it has gained importance to reveal chemotherapy-supporting strategies and reliable agents with their mechanisms of action. Tannic acid (TA), a naturally occurring plant polyphenol, has diverse physiological effects, including anti-inflammatory, anticarcinogenic, antioxidant, and radical scavenging properties. Therefore, this study was designed to investigate whether TA exerts a protective effect on mechanisms contributing to anthracycline-induced cardiotoxicity in rat heart tissues exposed to doxorubicin (DOX). Rats were randomly divided into control and experimental groups and treated with (18mg/kg) DOX, TA (50mg/kg), and DOX+TA during the 2 weeks. Cardiac gene markers and mitochondrial DNA (mtDNA) content were evaluated in the heart tissues of all animals. In addition to major metabolites, mRNA expression changes and biological activity responses of components of antioxidant metabolism were examined in the heart tissues of all animals. The expression of cardiac gene markers increased by DOX exposure was significantly reduced by TA treatment, whereas mtDNA content, which was decreased by DOX exposure, was significantly increased. TA also improved antioxidant metabolism members' gene expression and enzymatic activity, including glutathione peroxidase, glutathione s-transferase, superoxide dismutase, catalase, and thioredoxin reductase. This study provides a detailed overview of the current understanding of DOX-induced cardiotoxicity and preventive or curative measures involving TA.

Secondary Metabolites and Biological Activities of an Endophytic Fungus from Tussilago farfara

Secondary Metabolites and Biological Activities of an Endophytic Fungus from Tussilago farfara

Biological activity of soil bacteria that stimulate plant growth: nnitrogen fixation, phosphate solubilization, synthesis of siderophores. prospects for the development of microbial consortiums

The review provides literature data on soil bacteria that fix atmospheric nitrogen, solubilize phosphates and synthesize siderophores, thereby stimulating plant growth.The prospects of creating bacterial consortia for application to the soil in order to increase crop productivity and reduce the doses of fertilizers are considered.The use of rhizospheric bacteria capable of fixing atmospheric nitrogen, mineralizing inorganic and organic phosphates, increasing the bioavailability of insoluble iron, as well as their consortia, meets the objectives of sustainable agriculture, increases soil fertility and increases crop yields.The combined use of bacteria that stimulate plant growth with mineral fertilizers makes it possible to reduce the amount of fertilizers applied, which is an undoubted trend in sustainable agriculture.Research on the possibility of using various preparations of soil bacteria that stimulate plant growth has been widely carried out abroad in recent years, these studies are relevant forRussian agriculture, have prospects for import substitution and are necessary to achieve technological sovereignty in this area.

Children of Nature: Thoughts on Targeted and Untargeted Analytical Approaches to Decipher Polyphenol Reactivity in Food Processing and Metabolism.

Following 25 years of polyphenol research in our laboratory, the astonishing chemical and metabolic reactivity of polyphenols resulting in considerable chemical diversity has emerged as the most remarkable attribute of this class of natural products. To illustrate this concept, we will present selected data from black tea and coffee chemistry. In black tea chemistry, enzymatic fermentation converts six catechin derivatives into an estimated 30 000 different polyphenolic compounds via a process we have termed the oxidative cascade process. In coffee roasting, around 45 chlorogenic acids are converted into an estimated 250 novel derivatives following a series of diverse chemical transformations. Following ingestion by humans, these dietary polyphenols, whether genuine secondary metabolites or food processing products, encounter the microorganisms of the gut microbiota, converting them into a myriad of novel structures. In the case of coffee, only two out of 250 chlorogenic acids are absorbed intact, with most others being subject to gut microbial metabolism. Modern mass spectrometry (MS) has been key in unravelling the true complexity of polyphenols subjected to food processing and metabolism. We will accompany this assay with a short overview on analytical strategies developed, including ultrahigh-resolution MS, tandem MS, multivariate statistics, and molecular networking that allow an insight into the fascinating chemical processes surrounding dietary polyphenols. Finally, experimental results studying biological activity of polyphenols will be presented and discussed, highlighting a general promiscuity of this class of compounds associated with nonselective protein binding leading to loss of enzymatic function, another noteworthy general property of many dietary polyphenols frequently overlooked.

Establishing the Thermodynamic Cards of Dipine Models’ Oxidative Metabolism on 21 Potential Elementary Steps

Dipines are a type of important antihypertensive drug as L-calcium channel blockers, whose core skeleton is the 1,4-dihydropyridine structure. Since the dihydropyridine ring is a key structural factor for biological activity, the thermodynamics of the aromatization dihydropyridine ring is a significant feature parameter for understanding the mechanism and pathways of dipine metabolism in vivo. Herein, 4-substituted-phenyl-2,6-dimethyl-3,5-diethyl-formate-1,4-dihydropyridines are refined as the structurally closest dipine models to investigate the thermodynamic potential of dipine oxidative metabolism. In this work, the thermodynamic cards of dipine models’ aromatization on 21 potential elementary steps in acetonitrile have been established. Based on the thermodynamic cards, the thermodynamic properties of dipine models and related intermediates acting as electrons, hydrides, hydrogen atoms, protons, and two hydrogen ions (atoms) donors are discussed. Moreover, the thermodynamic cards are applied to evaluate the redox properties, and judge or reveal the possible oxidative mechanism of dipine models.

Approaches based on natural products and miRNAs in pituitary adenomas: unveiling therapeutic intervention.

Pituitary adenomas (PAs) are tumors originating in the pituitary gland, a small gland located at the base of the brain. They are the most common type of pituitary tumor, affecting approximately 1 in 10 people over their lifetime. Common symptoms include headaches, vision problems, hormonal imbalances, and weight changes. Treatment options depend on the type and size of the adenoma and may consist of medication, surgery, radiation therapy, or a combination. PAs are typically benign and slow-growing, but they can cause significant health issues if left untreated. Proper diagnosis and management by an experienced multidisciplinary team is important for achieving the best outcomes. Natural compounds like celastrol, curcumin, quercetin, apigenin, resveratrol, epigallocatechin gallate (EGCG), and genistein have shown the ability to inhibit cell growth, promote cell death, and suppress hormone activity in pituitary tumor cells, suggesting their potential as alternative or complementary treatments for PAs. MicroRNAs (miRNAs) are a kind of tiny RNA molecules that do not code for proteins and have a vital function in controlling gene expression. These 21-23 nucleotide-long molecules regulate gene expression by binding to complementary sequences in mRNA molecules, leading to mRNA degradation. miRNAs participate in a wide range of biological activities, including apoptosis, metastasis, differentiation, and proliferation. The research indicates that miRNAs play a crucial role in the pathogenesis, therapeutic approaches, diagnosis, and prognosis of PAs. This review article will provide a comprehensive analysis of the current understanding of the efficacy of naturally derived anti-cancer agents in the treatment of PAs. Furthermore, the study provides a comprehensive assessment of the miRNAs in PAs, their role in the development of PAs, and their potential application in the treatment of the condition.

Composite Nanoarchitectonics of Electrospun Piezoelectric PVDF/AgNPs for Biomedical Applications, Including Breast Cancer Treatment

This study focused on preparing composite nanomats by incorporating silver nanoparticles (AgNPs) in polyvinylidene fluoride (PVDF) nanofibers through the electrospinning process. A short review of piezoelectric PVDF-related research is presented. PVDF is known for its biocompatibility and piezoelectric properties. Since electrical signals in biological tissues have been shown to be relevant for therapeutic applications, the influence of the addition of AgNPs to PVDF on its piezoelectricity is studied, due to the ability of AgNPs to increase the piezoelectric signal, along with providing antibacterial properties. The prepared samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. In addition, the biological activity of composites was examined using a cytotoxicity assay and an assessment of the antibacterial activity. The obtained results show that the incorporation of AgNPs into PVDF nanofibers further enhances the piezoelectricity (crystalline β-phase fraction), already improved by the electrospinning process, compared to solution-casted samples, but only with a AgNPs/PVDF concentration of up to 0.3%; a further increase in the nanoparticles led to a β-phase reduction. The cytotoxicity assay showed a promising effect of PVDF/AgNPs nanofibers on the MDA-MB-231 breast cancer cell line, following the non-toxicity displayed in regard to the healthy MRC-5 cell line. The antibacterial effect of PVDF/AgNPs nanofibers showed promising antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus, as a result of the Ag content. The anticancer activity, combined with the electrical properties of nanofibers, presents new possibilities for smart, multifunctional materials for cancer treatment development.

Nrf1 Reduces COX-2 Expression and Maintains Cellular Homeostasis After Cerebral Ischemia/Reperfusion By Targeting IL-6/TNF-α Protein Production.

Neuroinflammation has been considered involved in the process of cerebral ischemia-reperfusion injury (CIRI). Transcription factors play a crucial role in regulating gene transcription and the expressions of specific proteins during the progression of various neurological diseases. Evidence showed that transcription factor nuclear factor erythroid 2-related factor 1 (NFE2L1, also known as Nrf1) possessed strong biological activities including antioxidant, anti-inflammatory and neuroprotective properties. However, its role and potential molecular mechanisms in CIRI remain unclear. In our study, we observed a significant elevation of Nrf1 in the cerebral cortex following cerebral ischemia-reperfusion in rats. The Nrf1 downregulation markedly raised COX-2, TNF-α, IL-1β, and IL-6 protein levels during middle cerebral artery occlusion/reperfusion in rats, which led to worsened neurological deficits, higher cerebral infarct volume, and intensified cortical histopathological damage. In subsequent in vitro studies, the expression of Nrf1 protein increased following oxygen-glucose deprivation/reperfusion treatment on neurons. Subsequently, Nrf1 knockdown resulted in a significant upregulation of inflammatory factors, leading to a substantial increase in the cell death rate. Through analyzing the alterations in the expression of inflammatory factors under diverse interventions, it is indicated that Nrf1 possesses the capacity to discern variations in inflammatory factors via specific structural domains. Our findings demonstrate the translocation of the Nrf1 protein from the cytoplasm to the nucleus, thereby modulating the protein expression of IL-6/TNF-α and subsequently reducing the expression of multiple inflammatory factors. This study signifies, for the first time, that during cerebral ischemia-reperfusion, Nrf1 translocases to the nucleus to regulate the protein expression of IL-6/TNF-α, consequently suppressing COX-2 expression and governing cellular inflammation, ultimately upholding cellular homeostasis.

Antioxidant and antibacterial properties of ethanolic pot-pollen extract of Melipona beecheii and determination of the major components by GC-MS.

Melipona beecheii pot-pollen is a natural product that has barely been studied, unlike other hive products such as honey and propolis. Its application has been reported since ancient times in traditional Mayan medicine, and it is also a functional food with high nutritional value. In the present study, samples of ethanolic pot-pollen extracts from five locations in the Yucatán Peninsula were analyzed to determine their antibacterial and antioxidant properties. All the extracts showed activity against five medically important bacteria; Pseudomonas aeruginosa and Listeria monocytogenes were the most susceptible bacteria in all samples. The evaluated antioxidant activity was higher than that reported by other studies. Palmitic, linoleic, and linolenic fatty acids and their respective ethyl ethers were detected by Gas Chromatography-Mass Spectrometry (GC-MS) in all samples in different concentrations. Based on these results, pot-pollen extract from Mama, Yucatán exhibited the best biological activities (Minimum Inhibitory Concentrations (MICs) between 6 and 40 mg/mL, EC50 DPPH 28 µg/mL, EC50 RP 30 µg/mL), which could be related to a higher content of unsaturated fatty acids and their ethyl esters. The present study demonstrates that M. beecheii pot-pollen has therapeutic potential in addition to its benefits as a nutritional supplement.