Nanomedicine-mediated recovery of antioxidant glutathione peroxidase activity after oxidative-stress cellular damage: Insights for neurological long COVID.

Nanomedicine for treating post-viral infectious disease syndrome is at an emerging stage. Despite promising results from preclinical studies on conventional antioxidants, their clinical translation as a therapy for treating post-COVID conditions remains challenging. The limitations are due to their low bioavailability, instability, limited transport to the target tissues, and short half-life, requiring frequent and high doses. Activating the immune system during coronavirus (SARS-CoV-2) infection can lead to increased production of reactive oxygen species (ROS), depleted antioxidant reserve, and finally, oxidative stress and neuroinflammation. To tackle this problem, we developed an antioxidant nanotherapy based on lipid (vesicular and cubosomal types) nanoparticles (LNPs) co-encapsulating ginkgolide B and quercetin. The antioxidant-loaded nanocarriers were prepared by a self-assembly method via hydration of a lyophilized mixed thin lipid film. We evaluated the LNPs in a new in vitro model for studying neuronal dysfunction caused by oxidative stress in coronavirus infection. We examined the key downstream signaling pathways that are triggered in response to potassium persulfate (KPS) causing oxidative stress-mediated neurotoxicity. Treatment of neuronally-derived cells (SH-SY5Y) with KPS (50 mM) for 30 min markedly increased mitochondrial dysfunction while depleting the levels of both glutathione peroxidase (GSH-Px) and tyrosine hydroxylase (TH). This led to the sequential activation of apoptotic and necrotic cell death processes, which corroborates with the crucial implication of the two proteins (GSH-Px and TH) in the long-COVID syndrome. Nanomedicine-mediated treatment with ginkgolide B-loaded cubosomes and vesicular LNPs showed minimal cytotoxicity and completely attenuated the KPS-induced cell death process, decreasing apoptosis from 32.6% (KPS) to 19.0% (MO-GB), 12.8% (MO-GB-Quer), 14.8% (DMPC-PEG-GB), and 23.6% (DMPC-PEG-GB-Quer) via free radical scavenging and replenished GSH-Px levels. These findings indicated that GB-LNPs-based nanomedicines may protect against KPS-induced apoptosis by regulating intracellular redox homeostasis.

Strigolactones promote flowering by inducing the miR319-LA-SFT module in tomato.

Strigolactones are a class of phytohormones with various functions in plant development, stress responses, and in the interaction with (micro)organisms in the rhizosphere. While their effects on vegetative development are well studied, little is known about their role in reproduction. We investigated the effects of genetic and chemical modification of strigolactone levels on the timing and intensity of flowering in tomato (Solanum lycopersicum L.) and the molecular mechanisms underlying such effects. Results showed that strigolactone levels in the shoot, whether endogenous or exogenous, correlate inversely with the time of anthesis and directly with the number of flowers and the transcript levels of the florigen-encoding gene SINGLE FLOWER TRUSS (SFT) in the leaves. Transcript quantifications coupled with metabolite analyses demonstrated that strigolactones promote flowering in tomato by inducing the activation of the microRNA319-LANCEOLATE module in leaves. This, in turn, decreases gibberellin content and increases the transcription of SFT. Several other floral markers and morpho-anatomical features of developmental progression are induced in the apical meristems upon treatment with strigolactones, affecting floral transition and, more markedly, flower development. Thus, strigolactones promote meristem maturation and flower development via the induction of SFT both before and after floral transition, and their effects are blocked in plants expressing a miR319-resistant version of LANCEOLATE. Our study positions strigolactones in the context of the flowering regulation network in a model crop species.

Effect of novel anti-tumor and anti-angiogenesis drug taurolactone on angiogenic factor AGGF1 and angiogenesis mimicry in patients with hepatocellular carcinoma.

OBJECTIVE: Our study was to investigate the impact of taurolactone, a novel anti-tumor and anti-angiogenic drug, on AGGF1, an angiogenic factor, and angiogenesis mimicry in patients diagnosed with hepatocellular carcinoma (HCC). METHODS: A total of 120 HCC patients were enrolled from the Department of Oncology and Hepatobiliary Surgery at our hospital between May 2021 and December 2022. HCC diagnoses were confirmed through imaging or tissue biopsy for all patients. The age of patients ranged from 37 to 72 years, with an average age of 64.29 ± 4.58 years. These participants were divided equally into two groups: the control group and the observation group, each consisting of 60 individuals. While the control group received standard drug treatment, the observation group was administered taurolactone treatment. Before being included in the study, all participants or their legal representatives provided signed informed consent. Patient demographic information was collected through a questionnaire survey. ELISA was used to measure the levels of VEGF and AGGF1 in patients following treatment. Western blot was applied to assess the protein expression of PDGF, Angiopoietin, and AGGF1. MRI imaging technology was utilized to assess the perfusion characteristics of tumor blood vessels in patients. Tumor vessel density was compared between patients using ultrasonography. We also conducted a comparison between the two groups in terms of progression-free survival and overall survival. RESULTS: General patient information between the two groups showed no significant differences (P > 0.05). Of note, the observation group exhibited greatly lower levels of VEGF and AGGF1 compared to the control group (P < 0.05). Moreover, the levels of PDGF, Angiopoietin, and AGGF1 protein expression were significantly reduced in the observation group compared to the control group (P < 0.05). In terms of tumor perfusion, the observation group displayed lower average and maximum perfusion volumes in tumor blood vessels compared to the control group (P < 0.05). Additionally, the observation group demonstrated delayed peak times and arrival times of tumor blood vessels in comparison to the control group (P < 0.05). Furthermore, the density of tumor blood vessels was notably lower in the observation group compared to the control group (P < 0.05). Patients in the observation group had longer progression-free survival and overall survival than the control group (P < 0.05). CONCLUSION: In HCC patients, our study highlighted the potential efficacy of taurolactone treatment as it effectively inhibited angiogenic factors and angiogenesis mimicry, ultimately leading to an improved prognosis for these patients.

Baicalin Weakens the Virulence of Porcine Extraintestinal Pathogenic Escherichia coli by Inhibiting the LuxS/AI-2 Quorum-Sensing System.

Porcine extraintestinal pathogenic Escherichia coli (ExPEC) is a pathogenic bacterium that causes huge economic losses to the pig farming industry and considerably threatens human health. The quorum sensing (QS) system plays a crucial role in the survival and pathogenesis of pathogenic bacteria. Hence, it is a viable approach to prevent ExPEC infection by compromising the QS system, particularly the LuxS/AI-2 system. In this study, we investigated the effects of baicalin on the LuxS/AI-2 system of ExPEC. Baicalin at concentrations of 25, 50, and 100 µg/mL significantly diminished the survival ability of ExPEC in hostile environments and could inhibit the biofilm formation and autoagglutination ability in ExPEC. Moreover, baicalin dose-dependently decreased the production of AI-2 and down-regulated the expression level of luxS in PCN033. These results suggest that baicalin can weaken the virulence of PCN033 by inhibiting the LuxS/AI-2 system. After the gene luxS was deleted, AI-2 production in PCN033 was almost completely eliminated, similar to the effect of baicalin on the production of AI-2 in PCN033. This indicates that baicalin reduced the production of AI-2 by inhibiting the expression level of luxS in ExPEC. In addition, the animal experiment further showed the potential of baicalin as a LuxS/AI-2 system inhibitor to prevent ExPEC infection. This study highlights the potential of baicalin as a natural quorum-sensing inhibitor for therapeutic applications in preventing ExPEC infection by targeting the LuxS/AI-2 system.

Structure-Activity Relationships of Natural C-9-Methyl-Substituted 10-Membered Lactones and Their Semisynthetic Derivatives.

Fungal 10-membered lactones (TMLs), such as stagonolide A, herbarumin I, pinolidoxin, and putaminoxin, are promising candidates for the development of nature-derived herbicides. The aim of this study was to analyze the structure-activity relationships (SAR) of C-9-methyl-substituted TMLs with a multitarget bioassay approach to reveal compounds with useful (phytotoxic, entomotoxic, antimicrobial) or undesirable (cytotoxic) bioactivities. A new TML, stagonolide L (1), along with five known compounds (stagonolides D (2) and E (3), curvulides A (4) and B1/B2 (5a,b), and pyrenolide C (6)), were purified from cultures of the phytopathogenic fungus Stagonospora cirsii, and five semisynthetic derivatives of 3 and 4 (7-11) were obtained. The absolute configuration of 4 was revised to 2Z, 4S, 5S, 6R, and 9R. The identity of 5a,b and stagonolide H is discussed. The phytotoxicity of compound 4, the entomotoxicity of 5a,b, and nonselective toxicity of compound 6 are demonstrated. The latter confirms the hypothesis that the α,ß-unsaturated carbonyl group is associated with the high general toxicity of TML, regardless of its position in the ring and other substituents. The epoxide in compound 4 is important for phytotoxicity. The revealed SAR patterns will be useful for further rational design of TML-based herbicides including curvulide A analogs with a 4,5-epoxy group.

Efficacy of moxidectin, using various dose regimens, against JYD-34, a macrocyclic lactone resistant isolate of Dirofilaria immitis.

BACKGROUND: Macrocyclic lactones (MLs) are the only class of drugs currently commercially available that are effective for preventing heartworm disease. The data presented in this article provide information on the efficacy of oral moxidectin against JYD-34, a known ML-resistant Dirofilaria immitis isolate, when dogs are treated under various dosing regimens. METHODS: Fifty-two purpose-bred Beagle dogs were used in five laboratory studies. All dogs were inoculated with 50 D. immitis third-stage larvae (L3) (JYD-34 isolate) 30 days prior to the first treatment. Dogs were randomized to treatment (four to five animals in each group) with one, three, or five monthly doses of oral moxidectin ranging from 6 to 100 µg/kg body weight. In each study, control dogs were not treated. Five to 6 months after L3 inoculation, dogs were euthanized, and adult worms were counted to evaluate efficacy of the dosing regimens. RESULTS: Adult heartworms were recovered from all control dogs, with an overall geometric mean of 29.7 worms (range 15.2 to 38.0, individual counts ranged from 8 to 51). Five monthly doses of 6 µg/kg provided 83.3% and 90.2%, efficacy, and the same number of monthly doses of 9 µg/kg demonstrated 98.8% and 94.1% efficacy. Three monthly doses of 30 and 50 µg/kg demonstrated 97.9% and 99.0% efficacy, respectively, while a single dose of 100 µg/kg demonstrated 91.1% efficacy. CONCLUSIONS: Five monthly doses of 9 µg/kg provided similar or only marginally lower efficacy against JYD-34, a known ML-resistant isolate, compared to substantially higher doses administered for 3 months. This underscores the importance of duration of exposure to moxidectin when facing ML-resistant isolates. Repeated administration of lower doses of moxidectin are an alternative to higher doses in the prevention of heartworm disease associated with less susceptible or resistant isolates.

[Ginkgolide B: mechanisms of neurobiological effects, prospects for use in the therapy of Alzheimer's disease]. / Ginkgolid B: mekhanizmy neirobiologicheskikh effektov, perspektivy primeneniya v terapii bolezni Al'tsgeimera.

The review presents an analysis of experimental data on the study of neurobiological effects of ginkgolide B, which may find application in the therapy of Alzheimer's disease (AD). Ginkgolide B is a diterpene trilactone isolated from the leaves of the relict woody plant Ginkgo biloba L., which has been used for thousands of years in traditional Chinese medicine as a neuroprotective agent. In recent years, this compound has attracted attention because of its wide range of neurobiological effects. The neuroprotective effect of ginkgolide B on brain neurons when exposed to various neurotoxins has been established. This compound has also been shown to effectively protect neurons from the effects of beta-amyloid. Studies have revealed the ability of ginkgolide B to reduce microglia activity and regulate neurotransmitter release. In vivo experiments have shown that this substance significantly increases the expression of brain-derived neurotrophic factor (BDNF) and improves cognitive functions, including memory and learning. It is concluded that ginkgolide B, apparently, may find application in the future as a multi-targeted agent of complex therapy of AD.

Ergosterols with rare peroxide, oxetane ring moiety, and a lactone ring from Aspergillus spectabilis and their immunosuppressive activities.

Ten ergostane-type steroids, including seven undescribed ones named spectasteroids A-G, were obtained from Aspergillus spectabilis. Their structures and absolute configurations were determined based on HRESIMS, NMR, ECD calculations, and single-crystal X-ray diffraction analyses. Structurally, spectasteroid A was a unique example of aromatic ergostane-type steroid that featured a rare peroxide ring moiety; spectasteroid B contained a rare oxetane ring system formed between C-9 and C-14; and spectasteroid C was an unusual 3,4-seco-ergostane steroid with an extra lactone ring between C-3 and C-9. Spectasteroids F and G specifically showed inhibitory effects against concanavalin A-induced T lymphocyte proliferation and lipopolysaccharide-induced B lymphocyte proliferation, with IC50 values ranging from 2.33 to 4.22 µM. Spectasteroid F also showed excellent antimultidrug resistance activity, which remarkable enhanced the inhibitory activity of PTX on the colony formation of SW620/Ad300 cells.

Genotyping USA laboratory-maintained isolates and European clinical isolates of Dirofilaria immitis to assess macrocyclic lactone susceptibility or resistance at predictive SNP sites using droplet digital PCR.

Dirofilaria immitis is a parasitic nematode that causes cardiovascular dirofilariosis ("heartworm disease") primarily in canids. The principal approach for mitigating heartworm infection involves the use of macrocyclic lactone (ML) for prophylaxis. Recent research has substantiated the emergence of D. immitis displaying resistance to MLs in the USA. Numerous factors, such as the mobility of companion animals and competent vectors could impact the spread of drug resistance. Genomic analysis has unveiled that isolates resistant to ML exhibit unique genetic profiles when compared to their wild-type (susceptible) counterparts. Out of the ten single nucleotide polymorphism (SNP) markers validated in clinical samples of D. immitis from the USA, four have demonstrated their effectiveness in distinguishing between isolates with varying ML efficacy phenotypes. This study explores the potential of these confirmed SNPs for conducting surveillance studies. Genotypic analysis using SNP markers emerges as a valuable tool for carrying out surveys and evaluating individual clinical isolates. Two USA laboratory-maintained isolates (Berkeley, WildCat) and twenty-five random European clinical samples of either adult worms or microfilariae (mf) pools isolated from domestic dogs, were tested by droplet digital PCR (ddPCR)-based duplex assay. This approach elucidates genetic evidence pertaining to the development of drug resistance and provides baseline data on resistance related genotypes in Europe. The data on these clinical samples suggests genotypes consistent with the continued efficacy of ML treatment regimens in Europe. In addition, this assay can be significant in discriminating cases of drug-resistance from those possibly due to non-compliance to the recommended preventive protocols.

Three rare anti-inflammatory sesquiterpene lactones from Magnolia grandiflora.

Four new sesquiterpene lactones (SLs) (1-4), along with a biosynthetically related SL (5), have been isolated from the leaves of Magnolia grandiflora. Magrandate A (1) is notable as the first C18 homogemarane type SL, featuring a unique 1,7-dioxaspiro[4.4]nonan-6-one core. Compounds 2 and 3, representing the first instances of chlorine-substituted gemarane-type SL analogs in natural products, were also identified. The structures of these isolates were elucidated through a combination of spectroscopic data analysis, electronic circular dichroism calculations, and X-ray single-crystal diffraction analysis. All isolates demonstrated anti-inflammatory activity in lipopolysaccharide-stimulated RAW264.7 cells. Notably, 3-5 showed a significant inhibitory effect on nitric oxide production, with IC50 values ranging from 0.79 to 4.73 µmol·L-1. Additionally, 4 and 5 exhibited moderate cytotoxic activities against three cancer cell lines, with IC50 values between 3.09 and 11.23 µmol·L-1.

Enzymes with Lactonase Activity against Fungal Quorum Molecules as Effective Antifungals.

Since the growing number of fungi resistant to the fungicides used is becoming a serious threat to human health, animals, and crops, there is a need to find other effective approaches in the eco-friendly suppression of fungal growth. One of the main mechanisms of the development of resistance in fungi, as well as in bacteria, to antimicrobial agents is quorum sensing (QS), in which various lactone-containing compounds participate as signaling molecules. This work aimed to study the effectiveness of action of enzymes exhibiting lactonase activity against fungal signaling molecules. For this, the molecular docking method was used to estimate the interactions between these enzymes and different lactone-containing QS molecules of fungi. The catalytic characteristics of enzymes such as lactonase AiiA, metallo-ß-lactamase NDM-1, and organophosphate hydrolase His6-OPH, selected for wet experiments based on the results of computational modeling, were investigated. QS lactone-containing molecules (butyrolactone I and γ-heptalactone) were involved in the experiments as substrates. Further, the antifungal activity of the enzymes was evaluated against various fungal and yeast cells using bioluminescent ATP-metry. The efficient hydrolysis of γ-heptalactone by all three enzymes and butyrolactone I by His6-OPH was demonstrated for the first time. The high antifungal efficacy of action of AiiA and NDM-1 against most of the tested fungal cells was revealed.

Antibacterial insights into alternariol and its derivative alternariol monomethyl ether produced by a marine fungus.

Alternaria alternata FB1 is a marine fungus identified as a candidate for plastic degradation in our previous study. This fungus has been recently shown to produce secondary metabolites with significant antimicrobial activity against various pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and the notorious aquaculture pathogen Vibrio anguillarum. The antibacterial compounds were purified and identified as alternariol (AOH) and its derivative, alternariol monomethyl ether (AME). We found that AOH and AME primarily inhibited pathogenic bacteria (MRSA or V. anguillarum) by disordering cell division and some other key physiological and biochemical processes. We further demonstrated that AOH could effectively inhibit the unwinding activity of MRSA topoisomerases, which are closely related to cell division and are the potential action target of AOH. The antibacterial activities of AOH and AME were verified by using zebrafish as the in vivo model. Notably, AOH and AME did not significantly affect the viability of normal human liver cells at concentrations that effectively inhibited MRSA or V. anguillarum. Finally, we developed the genetic operation system of A. alternata FB1 and blocked the biosynthesis of AME by knocking out omtI (encoding an O-methyl transferase), which facilitated A. alternata FB1 to only produce AOH. The development of this system in the marine fungus will accelerate the discovery of novel natural products and further bioactivity study.IMPORTANCEMore and more scientific reports indicate that alternariol (AOH) and its derivative alternariol monomethyl ether (AME) exhibit antibacterial activities. However, limited exploration of their detailed antibacterial mechanisms has been performed. In the present study, the antibacterial mechanisms of AOH and AME produced by the marine fungus Alternaria alternata FB1 were disclosed in vitro and in vivo. Given their low toxicity on the normal human liver cell line under the concentrations exhibiting significant antibacterial activity against different pathogens, AOH and AME are proposed to be good candidates for developing promising antibiotics against methicillin-resistant Staphylococcus aureus and Vibrio anguillarum. We also succeeded in blocking the biosynthesis of AME, which facilitated us to easily obtain pure AOH. Moreover, based on our previous results, A. alternata FB1 was shown to enable polyethylene degradation.

Sesquiterpene Acids and Lactones from Inula Confertiflora with their Antibacterial Activities.

The phytochemical investigation of the leaves of Inula confertiflora, a medicinal plant endemic to Ethiopia, led to the isolation of 15 terpenoids; 1ß-hydroxy-α-costic acid (1), 3α-hydroxycostic acid (2), isotelekin (3), asperilin (4), carabrone (5), carpesioline (6), graveolide (7), inuviscolide (8), 8-epi-inuviscolide (9), 1ß,4ß-dihydroxy-5α(H)-guaia-10(14),11(13)-dien-8α,12-olide (10), isoinuviscolide (11), 4ß,10ß-dihydroxy-5α(H)-1,11(13)-guaidien-8α,12-olide (12), 4ß,10ß-dihydroxy-1ß(H)-5α(H)-guai-11(13)-en-8α,12-olide (13), 4ß,10α-dihydroxy-1ß(H)-5α(H)-guai-11(13)-en-8α,12-olide (14), 4ß,10α-dihydroxy-1α(H)-5α(H)-guai-11(13)-en-8α,12-olide (15). Herein, structural elucidation and full NMR data for compound 1 are presented for the first time. The structures were elucidated using NMR, HRESIMS, and by comparison with literature data. The relative configurations were defined by NOESY correlations and single-crystal X-ray crystallography. Herein, crystallography data of 6 and 7 were reported for the first time. The antibacterial efficacy of some of the isolated compounds was evaluated against two commonly dispersed environmental strains of Escherichia coli and Staphylococcus aureus. Compounds 1, 3, 6, 7, and 8 exhibited moderate antibacterial activities against the tested organisms. The chemotaxonomic significance of compounds is discussed.

Trilobolide-6-O-isobutyrate from Sphagneticola trilobata acts by inducing oxidative stress, metabolic changes and apoptosis-like processes by caspase 3/7 activation of human lung cancer cell lines.

BACKGROUND: Lung cancer, a chronic and heterogeneous disease, is the leading cause of cancer-related death on a global scale. Presently, despite a variety of available treatments, their effectiveness is limited, often resulting in considerable toxicity and adverse effects. Additionally, the development of chemoresistance in cancer cells poses a challenge. Trilobolide-6-O-isobutyrate (TBB), a natural sesquiterpene lactone extracted from Sphagneticola trilobata, has exhibited antitumor effects. Its pharmacological properties in NSCLC lung cancer, however, have not been explored. PURPOSE: This study evaluated the impact of TBB on the A549 and NCI-H460 tumor cell lines in vitro, examining its antiproliferative properties and initial mechanisms of cell death. METHODS: TBB, obtained at 98 % purity from S. trilobata leaves, was characterized using chromatographic techniques. Subsequently, its impact on inhibiting tumor cell proliferation in vitro, TBB-induced cytotoxicity in LLC-MK2, THP-1, AMJ2-C11 cells, as well as its effects on sheep erythrocytes, and the underlying mechanisms of cell death, were assessed. RESULTS: In silico predictions have shown promising drug-likeness potential for TBB, indicating high oral bioavailability and intestinal absorption. Treatment of A549 and NCI-H460 human tumor cells with TBB demonstrated a direct impact, inducing significant morphological and structural alterations. TBB also reduced migratory capacity without causing toxicity at lower concentrations to LLC-MK2, THP-1 and AMJ2-C11 cell lines. This antiproliferative effect correlated with elevated oxidative stress, characterized by increased levels of ROS, superoxide anion radicals and NO, accompanied by a decrease in antioxidant markers: SOD and GSH. TBB-stress-induced led to changes in cell metabolism, fostering the accumulation of lipid droplets and autophagic vacuoles. Stress also resulted in compromised mitochondrial integrity, a crucial aspect of cellular function. Additionally, TBB prompted apoptosis-like cell death through activation of caspase 3/7 stressors. CONCLUSION: These findings underscore the potential of TBB as a promising candidate for future studies and suggest its viability as an additional component in the development of novel anticancer drugs prototypes.

Synthesis and Anti-Inflammatory Activity of Ferulic Acid-Sesquiterpene Lactone Hybrids.

Acute lung injury (ALI) is a respiratory failure disease associated with high mortality rates in patients. The primary pathological damage is attributed to the excessive release of pro-inflammatory mediators in pulmonary tissue. However, specific therapy for ALI has not been developed. In this study, a series of novel ferulic acid-parthenolide (FA-PTL) and ferulic acid-micheliolide (FA-MCL) hybrid derivatives were designed, synthesized, and evaluated for their anti-inflammatory activities in vitro. Compounds 2, 4, and 6 showed pronounced anti-inflammatory activity against LPS-induced expression of pro-inflammatory cytokines in vitro. Importantly, compound 6 displayed good water solubility, and treatment of mice with compound 6 (10 mg/kg) significantly prevented weight loss and ameliorated inflammatory cell infiltration and edema in lung tissue, as well as improving the alveolar structure. These results suggest that compound 6 (((1aR,7aS,8R,10aS,10bS,E)-8-((dimethylamino)methyl)-1a-methyl-9-oxo-1a,2,3,6,7,7a,8,9,10a,10b-decahydrooxireno[2',3':9,10]cyclodeca[1,2-b]furan-5-yl)methyl (E)-3-(4-hydroxy-3-methoxyphenyl)acrylate 2-hydroxypropane-1,2,3-tricarboxylate) might be considered as a lead compound for further evaluation as a potential anti-ALI agent.

Non-pathogenic Heyndrickxia coagulans (Bacillus coagulans) 29-2E inhibits the virulence of pathogenic Salmonella Typhimurium by quorum-sensing regulation.

Bacteria produce and release small signal molecules, autoinducers, as an indicator of their cell density. The system, called a quorum-sensing (QS) system, is used to control not only virulence factors but also antibiotic production, sporulation, competence, and biofilm formation in bacteria. Different from antibiotics, QS inhibitors are expected to specifically repress the virulence factors in pathogenic bacteria without inhibiting growth or bactericidal effects. Therefore, since QS inhibitors have little risk of antibiotic-resistant bacteria emergence, they have been proposed as promising anti-bacterial agents. In the present study, we aimed to find new QS inhibitors that prohibit the signaling cascade of autoinducer 3 (AI-3) recognized by a QseCB two-component system that regulates some virulence factors of pathogens, such as enterohemorrhagic Escherichia coli (EHEC) and Salmonella enterica subsp. enterica serovar Typhimurium. We have established the method for QS-inhibitor screening using a newly constructed plasmid pLES-AQSA. E. coli DH5α transformed with the pLES-AQSA can produce ß-galactosidase that converts 5-bromo-4-chloro-3-indolyl ß-d-galactopyranoside (X-gal) into blue pigment (5-bromo-4-chloro-indoxyl) under the control of the QseCB system. By screening, Heyndrickxia coagulans (formerly Bacillus coagulans) 29-2E was found to produce an exopolysaccharide (EPS)-like water-soluble polymer that prohibits QseCB-mediated ß-galactosidase production without antibacterial activities. Further, the simultaneous injection of the 29-2E strain significantly improves the survival rate of Salmonella Typhimurium-infected silkworm larvae (from 0% to 83.3%), suggesting that the substance may be a promising inhibitor against the virulence of pathogens without risk of the emergence of antibiotic-resistant bacteria.

Evaluation of a novel triple-action adulticide containing a pyrethroid, macrocyclic lactone, and fatty acid against pyrethroid-resistant Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae).

Insecticide resistance in mosquito populations has long been recognized as a significant global public health challenge, motivating the development of new control chemistries. ReMoa Tri is a novel triple-action space spray that employs a different mode of action than traditional adult mosquito control formulations. It combines 3 components: fenpropathrin, a mixed-type I/II pyrethroid; abamectin, a macrocyclic lactone; and C8910, a patented fatty acid chain. As an ultra-low volume adulticide, ReMoa Tri has the potential to target mosquito species that are resistant to pyrethroid and organophosphate-based control materials. To determine whether ReMoa Tri effectively targets resistant mosquito species in Florida's Collier County, United States, we conducted ground-based field cage trials using field-caught pyrethroid-resistant Culex quinquefasciatus (Say) and Aedes aegypti (L.), of which the latter also displayed developing resistance to organophosphates. Trials were also conducted against the same mosquito populations with Merus 3.0, a pyrethrin-based adulticide used by the Collier Mosquito Control District. ReMoa Tri was effective against Collier's pyrethroid-resistant Cx. quinquefasciatus, resulting in more than 95% mortality in semifield cage trials by 24 h postapplication. Similarly, ReMoa Tri applications against Collier's pyrethroid-resistant Ae. aegypti resulted in 72%-89% mortality at 24 h postapplication and 74%-97% mortality at 48 h postapplication. This study represents the first field data on this novel space spray, and its findings shed light on the performance of ReMoa Tri against local mosquito populations that have developed resistance to currently available adulticides.

Total Synthesis, Structure Reassignment, and Biological Evaluation of the Anti-Inflammatory Macrolactone 13-Hydroxy-14-deoxyoxacyclododecindione.

Herein, the first total synthesis of natural 13-hydroxy-14-deoxyoxacyclododecindione along with the revision of the proposed configuration is reported. This natural product, initially discovered in 2018, belongs to the oxacyclododecindione family, renowned for their remarkable anti-inflammatory and antifibrotic activities. The synthetic route involves an esterification/Friedel-Crafts-acylation approach and uses various triol fragments. It allows the preparation of different stereoisomers, including the (revised) natural product, two threo-derivatives, and two Z-isomers of the endocyclic C═C double bond. Furthermore, a late-stage inversion of the C-13 stereocenter could transform the originally proposed structure into the revised natural product. With this comprehensive set of compounds and the previously prepared (13R,14S,15R)-isomer, deeper insights into their structural properties and biological activities were obtained. A detailed analysis of the final macrolactones using spectroscopy (NMR, IR, UV-vis) and X-ray crystallography gave new insights such as the significance of the optical rotation for the elucidation of their configuration and the light-induced E/Z double-bond photoisomerization. The pharmacological potential of the compounds was underlined by remarkably low IC50 values in biological assays addressing the inhibition of cellular inflammatory responses.

The anti-apoptotic role of Ginkgolide B via mitochondrial permeability transition pore inhibition in retinal ischemia-reperfusion.

This research delves into the effectiveness of Ginkgolide B (GB), a compound from Ginkgo biloba, in combating cell death caused by glaucoma, with a focus on mitochondrial impairment and the mitochondrial permeability transition pore (mPTP). Utilizing models of high intraocular pressure and in vitro glaucoma simulations, the study investigates GB's impact on retinal progenitor cells (RPCs) under oxygen-glucose deprivation/reperfusion (OGD/R) and in a rat glaucoma model. The study methodologies included apoptosis assessment, apoptotic marker analysis via Western blot, and mitochondrial structure and function evaluation. The findings reveal that GB notably decreases apoptosis in RPCs exposed to OGD/R in vitro, and reduces ischemia-reperfusion damage in vivo. GB's protective role is attributed to its ability to preserve mitochondrial integrity, maintain membrane potential, regulate calcium levels, and inhibit mPTP opening. These results underscore GB's potential as a therapeutic agent for acute primary angle-closure glaucoma, highlighting its capability to alleviate mitochondrial damage and apoptosis in RPCs and retinal nerve fiber layer cells.

Development and characterization of liposomal formulations containing sesquiterpene lactones for the treatment of chronic gout.

Gout and hyperuricemia are characterized by high uric acid levels, and their treatment involves medications that have adverse effects. In this study, we evaluated oral liposomal formulations with eremantholide C and goyazensolide as a novel approach to reduce the toxicity associated with these substances while maintaining their anti-hyperuricemic activity. We characterized the formulations and evaluated them based on encapsulation efficiency and stability over 12 months and under simulated physiological environments. We determined the toxicity of the liposomal formulations in Caco-2 cells and the anti-hyperuricemic activity in rats. The formulations exhibited nanometric size, a narrow size distribution, and a negative zeta potential, indicating their stability and uniformity. The efficient encapsulation of the sesquiterpene lactones within the liposomes emphasizes their potential for sustained release and therapeutic efficacy. Stability evaluation revealed a small decrease in the eremantholide C concentration and a remarkable stability in the goyazensolide concentration. In Caco-2 cells, the liposomes did not exert toxicity, but did exhibit an antiproliferative effect. In vivo assays demonstrated that the liposomes reduced serum uric acid levels. Our study represents an advancement in gout and hyperuricemia treatment. The liposomal formulations effectively reduced the toxicity associated with the sesquiterpene lactones while maintaining their therapeutic effects.