Ipconazole Disrupts Mitochondrial Homeostasis and Alters GABAergic Neuronal Development in Zebrafish

Ipconazole, a demethylation inhibitor of fungal ergosterol biosynthesis, is widely used in modern agriculture for foliar and seed treatment, and is authorized for use in livestock feed. Waste from ipconazole treatment enters rivers and groundwater through disposal and rain, posing potential toxicity to humans and other organisms. Its metabolites remain stable under standard hydrolysis conditions; however, their neurodevelopmental toxicity is unknown. We investigated the potential neurodevelopmental toxicity of ipconazole pesticides in zebrafish (Danio rerio). Our behavioral monitoring demonstrated that the locomotive activity of ipconazole-exposed zebrafish larvae was reduced during early development, even when morphological abnormalities were undetected. Molecular profiling demonstrated that the mitochondrial-specific antioxidants, superoxide dismutases 1 and 2, and the genes essential for mitochondrial genome maintenance and functions were specifically reduced in ipconazole-treated (0.02 μg/mL) embryos, suggesting underlying ipconazole-driven oxidative stress. Consistently, ipconazole treatment substantially reduced hsp70 expression and increased ERK1/2 phosphorylation in a dose-dependent manner. Interrupted gad1b expression confirmed that GABAergic inhibitory neurons were dysregulated at 0.02 μg/mL ipconazole, whereas glutamatergic excitatory and dopaminergic neurons remained unaffected, resulting in an uncoordinated neural network. Additionally, ipconazole-treated (2 μg/mL) embryos exhibited caspase-independent cell death. This suggests that ipconazole has the potential to alter neurodevelopment by dysregulating mitochondrial homeostasis.     

Cryptotanshinone Alleviates Oxidative Stress and Reduces the Level of Abnormally Aggregated Protein in Caenorhabditis elegans AD Models

Alzheimer’s disease (AD) is one of the leading causes of dementia. As the first common neurodegenerative disease, there are no effective drugs that can reverse the progression. The present study is to report the anti-AD effect of cryptotanshinone (CTS), a natural product isolated from Salvia castanea. It is found that it can alleviate AD-like features associated with Aβ_1-42 toxicity in muscle cells as well as neuronal cells of Caenorhabditis elegans (C. elegans). Further studies showed that CTS reduced the level of reactive oxygen species (ROS) in nematodes, up-regulated the expression of sod-3, and enhanced superoxide dismutase activity. Cryptotanshinone reduced the level of Aβ monomers and highly toxic oligomers in C. elegans while inhibiting the abnormal aggregation of polyglutamine protein. In addition, CTS upregulated the expression of hsp-16.2 and downregulated the expression of ace-2. These results suggested that CTS could alleviate oxidative stress and reduce the level of abnormally aggregated proteins and has the potential to be developed as an anti-AD drug candidate.     

Diterpenoid Caesalmin C Delays Aβ-Induced Paralysis Symptoms via the DAF-16 Pathway in Caenorhabditis elegans

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease in the world. However, there is no effective drug to cure it. Caesalmin C is a cassane-type diterpenoid abundant in Caesalpinia bonduc (Linn.) Roxb. In this study, we investigated the effect of caesalmin C on Aβ-induced toxicity and possible mechanisms in the transgenic Caenorhabditis elegans AD model. Our results showed that caesalmin C significantly alleviated the Aβ-induced paralysis phenotype in transgenic CL4176 strain C. elegans. Caesalmin C dramatically reduced the content of Aβ monomers, oligomers, and deposited spots in AD C. elegans. In addition, mRNA levels of sod-3, gst-4, and rpt-3 were up-regulated, and mRNA levels of ace-1 were down-regulated in nematodes treated with caesalmin C. The results of the RNAi assay showed that the inhibitory effect of caesalmin C on the nematode paralysis phenotype required the DAF-16 signaling pathway, but not SKN-1 and HSF-1. Further evidence suggested that caesalmin C may also have the effect of inhibiting acetylcholinesterase (AchE) and upregulating proteasome activity. These findings suggest that caesalmin C delays the progression of AD in C. elegans via the DAF-16 signaling pathway and that it could be developed into a promising medication to treat AD.     

Effects of Microcystin-LR Exposure on Spermiogenesis in Nematode Caenorhabditis elegans

Little is known about the effect on spermiogenesis induced by microcystin-leucine arginine (MC-LR), even though such data are very important to better elucidate reproductive health. In the current work, with the aid of nematode Caenorhabditis elegans (C. elegans) as an animal model, we investigated the defects on spermiogenesis induced by MC-LR. Our results showed that MC-LR exposure induced sperm morphology abnormality and caused severe defects of sperm activation, trans-activation, sperm behavior and competition. Additionally, the expression levels of spe-15 were significantly decreased in C. elegans exposed to MC-LR lower than 16.0 μg/L, while the expression levels of spe-10 and fer-1 could be significantly lowered in C. elegans even exposed to 1.0 μg/L of MC-LR. Therefore, the present study reveals that MC-LR can induce adverse effects on spermiogenesis, and those defects of sperm functions may be induced by the decreases of spe-10, spe-15 and fer-1 gene expressions in C. elegans.     

Lactobacillus pentosus MJM60383 Inhibits Lipid Accumulation in Caenorhabditis elegans Induced by Enterobacter cloacae and Glucose

Gut microbiota are known to play an important role in obesity. Enterobacter cloacae, a Gram-negative bacterium, has been considered a pathogenic bacterium related to obesity in the gut. In this study, we established an obesity model of C. elegans by feeding E. cloacae combined with a high glucose diet (HGD), which significantly induced lipid accumulation. An anti-lipid mechanism study revealed that the fatty acid composition and the expression level of fat metabolism-related genes were altered by feeding E. cloacae to C. elegans under HGD conditions. Lactic acid bacteria that showed antagonistic activity against E. cloacae were used to screen anti-obesity candidates in this model. Among them, L. pentosus MJM60383 (MJM60383) showed good antagonistic activity. C. eleans fed with MJM60383 significantly reduced lipid accumulation and triglyceride content. The ratio of C18:1Δ9/C18:0 was also changed in C. elegans by feeding MJM60383. In addition, the expression level of genes related to fatty acid synthesis was significantly decreased and the genes related to fatty acid β-oxidation were up-regulated by feeding MJM60383. Moreover, MJM60383 also exhibited a high adhesive ability to Caco-2 cells and colonized the gut of C. elegans. Thus, L. pentosus MJM60383 can be a promising candidate for anti-obesity probiotics. To the best of our knowledge, this is the first report that uses E. cloacae combined with a high-glucose diet to study the interactions between individual pathogens and probiotics in C. elegans.     

The Discovery of Novel Ferulic Acid Derivatives Incorporating Substituted Isopropanolamine Moieties as Potential Tobacco Mosaic Virus Helicase Inhibitors

Target-based drug design, a high-efficiency strategy used to guide the development of novel pesticide candidates, has attracted widespread attention. Herein, various natural-derived ferulic acid derivatives incorporating substituted isopropanolamine moieties were designed to target the tobacco mosaic virus (TMV) helicase. Bioassays demonstrating the optimized A₁₉, A₂₀, A₂₉, and A₃₁ displayed excellent in vivo antiviral curative abilities, affording corresponding EC₅₀ values of 251.1, 336.2, 347.1, and 385.5 μg/mL, which visibly surpassed those of commercial ribavirin (655.0 μg/mL). Moreover, configurational analysis shows that the R-forms of target compounds were more beneficial to aggrandize antiviral profiles. Mechanism studies indicate that R-A₁₉ had a strong affinity (K_d = 5.4 μM) to the TMV helicase and inhibited its ability to hydrolyze ATP (50.61% at 200 μM). Meanwhile, A₁₉ could down-regulate the expression of the TMV helicase gene in the host to attenuate viral replication. These results illustrate the excellent inhibitory activity of A₁₉ towards the TMV helicase. Additionally, docking simulations uncovered that R-A₁₉ formed more hydrogen bonds with the TMV helicase in the binding pocket. Recent studies have unambiguously manifested that these designed derivatives could be considered as promising potential helicase-based inhibitors for plant disease control.     

Antiproliferative Activity of β-Hydroxy-β-Arylalkanoic Acids

Article describes the synthesis of fifteen β-hydroxy-β-arylalkanoic acids by Reformatsky reaction using the 1-ethoxyethyl-2-bromoalkanoates, aromatic or cycloalkyl ketones or aromatic aldehydes. The short survey of previously reported synthetic procedures for title compounds, is given. The majority of obtained compounds exert antiproliferative activity in vitro toward human: HeLa, Fem-X cells, K562, and LS174 cells, having IC₅₀ values from 62.20 to 205 μM. The most active compound is 3-OH-2,2-di-Me-3-(4- biphenylyl)-butanoic acid, having the IC₅₀ value 62.20 μM toward HeLa cells. Seven examined compounds did not affect proliferation of healthy human blood peripheral mononuclear cells (PBMC and PBMC+ PHA), IC₅₀ > 300 μM. The preliminary QSAR results show that estimated lipophilicity of compounds influences their antiproliferative activity in the first place. The ability of dehydration, and the spatial arrangement of hydrophobic portion, HBD and HBA in molecules are has almost equal importance as lipophilicity.     

Isolation and Structure Characterization of an Antioxidative Glycopeptide from Mycelial Culture Broth of a Medicinal Fungus

A novel glycopeptide (Cs-GP1) with an average molecular weight (Mw) of 6.0 kDa was isolated and purified by column chromatography from the lower Mw fraction of exopolysaccharide (EPS) produced by a medicinal fungus Cordyceps sinensis Cs-HK1. Its carbohydrate moiety was mainly composed of glucose and mannose at 3.2:1.0 mole ratio, indicating an O-linked glycopeptide. The peptide chain contained relatively high mole ratios of aspartic acid, glutamic acid and glycine (3.3–3.5 relative to arginine) but relatively low ratios of tyrosine and histidine. The peptide chain sequence analyzed after trypsin digestion by LC-MS was KNGIFQFGEDCAAGSISHELGGFREFREFLKQAGLE. Cs-GP1 exhibited remarkable antioxidant capacity with a Trolox equivalent antioxidant capacity of 1183.8 μmol/g and a ferric reducing ability of 611.1 μmol Fe(II)/g, and significant protective effect against H₂O₂-induced PC12 cell injury at a minimum dose of 10 μg/mL. This is the first report on the structure and bioactivity of an extracellular glycopeptide from the Cordyceps species.     

New Molecules of Diterpene Origin with Inhibitory Properties toward α-Glucosidase

The incidence of diabetes mellitus (DM), one of the most common chronic metabolic disorders, has increased dramatically over the past decade and has resulted in higher rates of morbidity and mortality worldwide. The enzyme, α-Glucosidase (α-GLy), is considered a therapeutic target for the treatment of type 2 DM. Herein, we synthesized arylidene, heterocyclic, cyanoetoxy- and propargylated derivatives of quinopimaric acid (levopimaric acid diene adduct with p-benzoquinone) 1–50 and, first, evaluated their ability to inhibit α-GLy. Among the tested compounds, quinopimaric acid 1, 2,3-dihydroquinopimaric acid 8 and its amide and heterocyclic derivatives 9, 30, 33, 39, 44, with IC₅₀ values of 35.57–65.98 μM, emerged as being good inhibitors of α-GLy. Arylidene 1β-hydroxy and 1β,13α-epoxy methyl dihydroquinopimarate derivatives 6, 7, 26–29, thiadiazole 32, 1a,4a-dehydroquinopimaric acid 40 and its indole, nitrile and propargyl hybrids 35–38, 42, 45, 48, and 50 showed excellent inhibitory activities. The most active compounds 38, 45, 48, and 50 displayed IC₅₀ values of 0.15 to 0.68 μM, being 1206 to 266 more active than acarbose (IC₅₀ of 181.02 μM). Kinetic analysis revealed the most active diterpene indole with an alkyne substituent 45 as a competitive inhibitor with K_i of 50.45 μM. Molecular modeling supported this finding and suggested that the indole core plays a key role in the binding. Compound 45 also has favorable pharmacokinetic and safety properties, according to the computational ADMET profiling. The results suggested that quinopimaric acid derivatives should be considered as potential candidates for novel alternative therapies in the treatment of type 2 diabetes.     

AP2M1 Supports TGF-β Signals to Promote Collagen Expression by Inhibiting Caveolin Expression

The extracellular matrix (ECM) is important for normal development and disease states, including inflammation and fibrosis. To understand the complex regulation of ECM, we performed a suppressor screening using Caenorhabditis elegans expressing the mutant ROL-6 collagen protein. One cuticle mutant has a mutation in dpy-23 that encodes the μ2 adaptin (AP2M1) of clathrin-associated protein complex II (AP-2). The subsequent suppressor screening for dpy-23 revealed the lon-2 mutation. LON-2 functions to regulate body size through negative regulation of the tumor growth factor-beta (TGF-β) signaling pathway responsible for ECM production. RNA-seq analysis showed a dominant change in the expression of collagen genes and cuticle components. We noted an increase in the cav-1 gene encoding caveolin-1, which functions in clathrin-independent endocytosis. By knockdown of cav-1, the reduced TGF-β signal was significantly restored in the dpy-23 mutant. In conclusion, the dpy-23 mutation upregulated cav-1 expression in the hypodermis, and increased CAV-1 resulted in a decrease of TβRI. Finally, the reduction of collagen expression including rol-6 by the reduced TGF-β signal influenced the cuticle formation of the dpy-23 mutant. These findings could help us to understand the complex process of ECM regulation in organism development and disease conditions.     

Polyunsaturated fatty acids and T-cell function: Implications for the neonate

Infant survival depends on the ability to respond effectively and appropriately to environmental challenges. Infants are born with a degree of immunological immaturity that renders them susceptible to infection and abnormal dietary responses (allergies). T-lymphocyte function is poorly developed at birth. The reduced ability of infants to respond to mitogens may be the result, of the low number of CD45RO+ (memory/antigen-primed). T cells in the infant or the limited ability to produce cytokines [particularly interferon-γ, interleukin (IL)-4, and IL-10]. There have been many important changes in optimizing breast milk substitutes for infants; however, few have been directed at replacing factors in breast milk that convey immune benefits. Recent research has been directed at the neurological, retinal, and membrane benefits of adding 20∶4n−6 (arachidonic acid; AA) and 22∶6n−3 (docosahexaenoic acid; DHA) to infant formula. In addults and animals, feeding DHA affects T-cell function. However, the effect of these lipids on the development and function of the infant's immune system is not known. We recently reported the effect of adding DHA+AA to a standard infant formula on several functional indices of immune development. Compared with standard formula, feeding a formula containing DHA+AA increased the proporition of antigen mature (CD45RO+) CD4⁺ cells, improved IL-10 production, and reduced IL-2 production to levels not different from those of human milk-fed infants. This review will briefly describe T-cell development and the potential immune effect of feeding long-chain polyunsaturated fatty acids to the neonate.     

Curupira tefeensis II: Occurrence of Acetylenic Fatty Acids

Four acetylenic fatty acids [11-octadecen-9-ynoic acid (E) (ximenynic acid), 11-octadecen-9-ynoic acid (Z), 9,11-octadecadiynoic acid and 13-octadecen-9,11-diynoic acid (E) (exocarpic acid)] were found in the seed oil of Curupira tefeensis (Olacaceae) as minor compounds. The mass spectra of the methyl esters (EI and CI mode), picolinyl esters and 4,4-dimethyloxazoline derivatives of these acids are discussed in detail. Furthermore the NMR data of 9,11-octadecadiynoic acid and 13-octadecen-9,11-diynoic acid are presented.     

Preparation of Chitosan and Water-Soluble Chitosan Microspheres via Spray-Drying Method to Lower Blood Lipids in Rats Fed with High-Fat Diets

This experiment aimed to investigate the effects of the chitosan (CTS) and water-soluble chitosan (WSC) microspheres on plasma lipids in male Sprague-Dawley rats fed with high-fat diets. CTS microspheres and WSC microspheres were prepared by the spray-drying technique. Scanning electron microscopy (SEM) micrographs showed that the microspheres were nearly spherical in shape. The mean size of CTS microspheres was 4.07 μm (varying from 1.50 to 7.21 μm) and of WSC microspheres was 2.00 μm (varying from 0.85 to 3.58 μm). The rats were classified into eight groups (n = 8) and were fed with high-fat diets for two weeks to establish the hyperlipidemic condition and were then treated with CTS microspheres and WSC microspheres, CTS and WSC for four weeks. The results showed that CTS and WSC microspheres reduced blood lipids and plasma viscosity and increased the serum superoxide dismutase (SOD) levels significantly. This study is the first report of the lipid-lowering effects of CTS and WSC microspheres. CTS and WSC microspheres were found to be more effective in improving hyperlipidemia in rats than common CTS and WSC.     

A Novel Selenium Polysaccharide Alleviates the Manganese (Mn)-Induced Toxicity in Hep G2 Cells and Caenorhabditis elegans

Manganese (Mn) is now known to have a variety of toxicities, particularly when exposed to it in the workplace. However, there are still ineffective methods for reducing Mn’s hazardous effects. In this study, a new selenium polysaccharide (Se-PCS) was developed from the shell of Camellia oleifera to reduce Mn toxicity in vitro and in vivo. The results revealed that Se-PCS may boost cell survival in Hep G2 cells exposed to Mn and activate antioxidant enzyme activity, lowering ROS and cell apoptosis. Furthermore, after being treated with Se-PCS, Caenorhabditis elegans survived longer under Mn stress. daf-16, a tolerant critical gene, was turned on. Moreover, the antioxidant system was enhanced as the increase in strong antioxidant enzyme activity and high expression of the sod-3, ctl-2, and gst-1 genes. A variety of mutations were also used to confirm that Se-PCS downregulated the insulin signaling pathway. These findings showed that Se-PCS protected Hep G2 cells and C. elegans via the insulin/IGF-1 signaling pathway and that it could be developed into a promising medication to treat Mn toxicity.     

Cichoric Acid May Play a Role in Protecting Hair Cells from Ototoxic Drugs

Ototoxic hearing loss due to antibiotic medication including aminoglycosides and excess free radical production causes irreversible hair cell injury. Cichoric acid, a naturally occurring phenolic acid, has recently been found to exert anti-oxidative and anti-inflammatory properties through its free radical scavenging capacity. The present study aimed to investigate the protective effects of cichoric acid against neomycin-induced ototoxicity using transgenic zebrafish (pvalb3b: TagGFP). Our results indicated that cichoric acid in concentrations up to 5 μM did not affect zebrafish viability during the 2 h treatment period. Therefore, the otoprotective concentration of cichoric acid was identified as 5 μM under 2 h treatment by counting viable hair cells within the neuromasts of the anterior- and posterior-lateral lines in the study. Pretreatment of transgenic zebrafish with 5 μM of cichoric acid for 2 h significantly protected against neomycin-induced hair cell death. Protection mediated by cichoric acid was, however, lost over time. A terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and FM4-64 staining, respectively, provided in situ evidence that cichoric acid ameliorated apoptotic signals and mechanotransduction machinery impairment caused by neomycin. A fish locomotor test (distance move, velocity, and rotation frequency) assessing behavioral alteration after ototoxic damage revealed rescue due to cichoric acid pretreatment before neomycin exposure. These findings suggest that cichoric acid in 5 μM under 2 h treatment has antioxidant effects and can attenuate neomycin-induced hair cell death in neuromasts. Although cichoric acid offered otoprotection, there is only a small difference between pharmacological and toxic concentrations, and hence cichoric acid can be considered a rather prototypical compound for the development of safer otoprotective compounds.     

Conjugated Linoleic Acids Have Anti-Inflammatory Effects in Cultured Endothelial Cells

Conjugated linoleic acid (CLA) isomers may have a role in preventing atherosclerosis through the modulation of inflammation, particularly of the endothelium. However, whether low concentrations of CLAs are able to affect basal unstimulated endothelial cell (EC) responses is not clear. The aim of this study was to evaluate the effects of two CLAs (cis-9, trans-11 (CLA9,11) and trans-10, cis-12 (CLA10,12)) on the basal inflammatory responses by ECs. EA.hy926 cells (HUVEC lineage) were cultured under standard conditions and exposed to individual CLAs for 48 h. Both CLAs were incorporated into ECs in a dose-dependent manner. CLA9,11 (1 μM) significantly decreased concentrations of MCP-1 (p < 0.05), IL-6 (p < 0.05), IL-8 (p < 0.01) and RANTES (p < 0.05) in the culture medium. CLA10,12 (10 μM) decreased the concentrations of MCP-1 (p < 0.05) and RANTES (p < 0.05) but increased the concentration of IL-6 (p < 0.001). At 10 μM both CLAs increased the relative expression of the NFκβ subunit 1 gene (p < 0.01 and p < 0.05, respectively), while decreasing the relative expression of PPARα (p < 0.0001), COX-2 (p < 0.0001) and IL-6 (p < 0.0001) genes. CLA10,12 increased the relative expression of the gene encoding IκK-β at 10 μM compared with CLA9,11 (p < 0.05) and increased the relative expression of the gene encoding IκBα at 1 and 10 μM compared with linoleic acid (both p < 0.05). Neither CLA affected the adhesion of monocytes to ECs. These results suggest that low concentrations of both CLA9,11 and CLA10,12 have modest anti-inflammatory effects in ECs. Thus, CLAs may influence endothelial function and the risk of vascular disease. Nevertheless, at these low CLA concentrations some pro-inflammatory genes are upregulated while others are downregulated, suggesting complex effects of CLAs on inflammatory pathways.     

Rosmarinic Acid and Sodium Citrate Have a Synergistic Bacteriostatic Effect against Vibrio Species by Inhibiting Iron Uptake

Background: New strategies are needed to combat multidrug-resistant bacteria. The restriction of iron uptake by bacteria is a promising way to inhibit their growth. We aimed to suppress the growth of Vibrio bacterial species by inhibiting their ferric ion-binding protein (FbpA) using food components. Methods: Twenty spices were selected for the screening of FbpA inhibitors. The candidate was applied to antibacterial tests, and the mechanism was further studied. Results: An active compound, rosmarinic acid (RA), was screened out. RA binds competitively and more tightly than Fe³⁺ to VmFbpA, the FbpA from V. metschnikovii, with apparent K_D values of 8 μM vs. 17 μM. Moreover, RA can inhibit the growth of V. metschnikovii to one-third of the control at 1000 μM. Interestingly, sodium citrate (SC) enhances the growth inhibition effect of RA, although SC only does not inhibit the growth. The combination of RA/SC completely inhibits the growth of not only V. metschnikovii at 100/100 μM but also the vibriosis-causative pathogens V. vulnificus and V. parahaemolyticus, at 100/100 and 1000/100 μM, respectively. However, RA/SC does not affect the growth of Escherichia coli. Conclusions: RA/SC is a potential bacteriostatic agent against Vibrio species while causing little damage to indigenous gastrointestinal bacteria.     

Methylmercury Induces Mitochondria- and Endoplasmic Reticulum Stress-Dependent Pancreatic β-Cell Apoptosis via an Oxidative Stress-Mediated JNK Signaling Pathway

Methylmercury (MeHg), a long-lasting organic pollutant, is known to induce cytotoxic effects in mammalian cells. Epidemiological studies have suggested that environmental exposure to MeHg is linked to the development of diabetes mellitus (DM). The exact molecular mechanism of MeHg-induced pancreatic β-cell cytotoxicity is still unclear. Here, we found that MeHg (1-4 μM) significantly decreased insulin secretion and cell viability in pancreatic β-cell-derived RIN-m5F cells. A concomitant elevation of mitochondrial-dependent apoptotic events was observed, including decreased mitochondrial membrane potential and increased proapoptotic (Bax, Bak, p53)/antiapoptotic (Bcl-2) mRNA ratio, cytochrome c release, annexin V-Cy3 binding, caspase-3 activity, and caspase-3/-7/-9 activation. Exposure of RIN-m5F cells to MeHg (2 μM) also induced protein expression of endoplasmic reticulum (ER) stress-related signaling molecules, including C/EBP homologous protein (CHOP), X-box binding protein (XBP-1), and caspase-12. Pretreatment with 4-phenylbutyric acid (4-PBA; an ER stress inhibitor) and specific siRNAs for CHOP and XBP-1 significantly inhibited their expression and caspase-3/-12 activation in MeHg-exposed RIN-mF cells. MeHg could also evoke c-Jun N-terminal kinase (JNK) activation and reactive oxygen species (ROS) generation. Antioxidant N-acetylcysteine (NAC; 1mM) or 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox; 100 μM) markedly prevented MeH-induced ROS generation and decreased cell viability in RIN-m5F cells. Furthermore, pretreatment of cells with SP600125 (JNK inhibitor; 10 μM) or NAC (1 mM) or transfection with JNK-specific siRNA obviously attenuated the MeHg-induced JNK phosphorylation, CHOP and XBP-1 protein expression, apoptotic events, and insulin secretion dysfunction. NAC significantly inhibited MeHg-activated JNK signaling, but SP600125 could not effectively reduce MeHg-induced ROS generation. Collectively, these findings demonstrate that the induction of ROS-activated JNK signaling is a crucial mechanism underlying MeHg-induced mitochondria- and ER stress-dependent apoptosis, ultimately leading to β-cell death.     

Effects of Luteolin on Biofilm of Trueperella pyogenes and Its Therapeutic Effect on Rat Endometritis

Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in animals. The development of new anti-biofilm drugs will improve the current treatment status for controlling T. pyogenes infections in the animal husbandry industry. Luteolin is a naturally derived flavonoid compound with antibacterial properties. In this study, the effects and the mechanism of luteolin on T. pyogenes biofilm were analyzed and explored. The MBIC and MBEC of luteolin on T. pyogenes were 156 μg/mL and 312 μg/mL, respectively. The anti-biofilm effects of luteolin were also observed by a confocal laser microscope and scanning electron microscope. The results indicated that 312 μg/mL of luteolin could disperse large pieces of biofilm into small clusters after 8 h of treatment. According to the real-time quantitative PCR detection results, luteolin could significantly inhibit the relative expression of the biofilm-associated genes luxS, plo, rbsB and lsrB. In addition, the in vivo anti-biofilm activity of luteolin against T. pyogenes was studied using a rat endometritis model established by glacial acetic acid stimulation and T. pyogenes intrauterine infusion. Our study showed that luteolin could significantly reduce the symptoms of rat endometritis. These data may provide new opinions on the clinical treatment of luteolin and other flavonoid compounds on T. pyogenes biofilm-associated infections.     

Trans-Chalcone Plus Baicalein Synergistically Reduce Intracellular Amyloid Beta (Aβ42) and Protect from Aβ42 Induced Oxidative Damage in Yeast Models of Alzheimer’s Disease

Finding an effective therapeutic to prevent or cure AD has been difficult due to the complexity of the brain and limited experimental models. This study utilized unmodified and genetically modified Saccharomyces cerevisiae as model organisms to find potential natural bioactive compounds capable of reducing intracellular amyloid beta 42 (Aβ₄₂) and associated oxidative damage. Eleven natural bioactive compounds including mangiferin, quercetin, rutin, resveratrol, epigallocatechin gallate (EGCG), urolithin A, oleuropein, rosmarinic acid, salvianolic acid B, baicalein and trans-chalcone were screened for their ability to reduce intracellular green fluorescent protein tagged Aβ₄₂ (GFP-Aβ₄₂) levels. The two most effective compounds from the screens were combined in varying concentrations of each to study the combined capacity to reduce GFP-Aβ₄₂. The most effective combinations were examined for their effect on growth rate, turnover of native Aβ₄₂ and reactive oxygen species (ROS). The bioactive compounds except mangiferin and urolithin A significantly reduced intracellular GFP-Aβ₄₂ levels. Baicalein and trans-chalcone were the most effective compounds among those that were screened. The combination of baicalein and trans-chalcone synergistically reduced GFP-Aβ₄₂ levels. A combination of 15 μM trans-chalcone and 8 μM baicalein was found to be the most synergistic combination. The combination of the two compounds significantly reduced ROS and Aβ₄₂ levels in yeast cells expressing native Aβ₄₂ without affecting growth of the cells. These findings suggest that the combination of baicalein and trans-chalcone could be a promising multifactorial therapeutic strategy to cure or prevent AD. However, further studies are recommended to look for similar cytoprotective activity in humans and to find an optimal dosage.