Lactobacillus acidophilus suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma through producing valeric acid.

BACKGROUND: Gut probiotic depletion is associated with non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). Here, we investigated the prophylactic potential of Lactobacillus acidophilus against NAFLD-HCC. METHODS: NAFLD-HCC conventional and germ-free mice were established by diethylnitrosamine (DEN) injection with feeding of high-fat high-cholesterol (HFHC) or choline-deficient high-fat (CDHF) diet. Orthotopic NAFLD-HCC allografts were established by intrahepatic injection of murine HCC cells with HFHC feeding. Metabolomic profiling was performed using liquid chromatography-mass spectrometry. Biological functions of L. acidophilus conditional medium (L.a CM) and metabolites were determined in NAFLD-HCC human cells and mouse organoids. FINDINGS: L. acidophilus supplementation suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice. This was confirmed in orthotopic allografts and germ-free tumourigenesis mice. L.a CM inhibited the growth of NAFLD-HCC human cells and mouse organoids. The protective function of L. acidophilus was attributed to its non-protein small molecules. By metabolomic profiling, valeric acid was the top enriched metabolite in L.a CM and its upregulation was verified in liver and portal vein of L. acidophilus-treated mice. The protective function of valeric acid was demonstrated in NAFLD-HCC human cells and mouse organoids. Valeric acid significantly suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice, accompanied by improved intestinal barrier integrity. This was confirmed in another NAFLD-HCC mouse model induced by CDHF diet and DEN. Mechanistically, valeric acid bound to hepatocytic surface receptor GPR41/43 to inhibit Rho-GTPase pathway, thereby ablating NAFLD-HCC. INTERPRETATION: L. acidophilus exhibits anti-tumourigenic effect in mice by secreting valeric acid. Probiotic supplementation is a potential prophylactic of NAFLD-HCC. FUNDING: Shown in Acknowledgments.

In Vivo and In Silico Analgesic Activity of Ficus populifolia Extract Containing 2-O-ß-D-(3',4',6'-Tri-acetyl)-glucopyranosyl-3-methyl Pentanoic Acid.

Natural product-based structural templates have immensely shaped small molecule drug discovery, and new biogenic natural products have randomly provided the leads and molecular targets in anti-analgesic activity spheres. Pain relief achieved through opiates and non-steroidal anti-inflammatory drugs (NSAIDs) has been under constant scrutiny owing to their tolerance, dependency, and other organs toxicities and tissue damage, including harm to the gastrointestinal tract (GIT) and renal tissues. A new, 3',4',6'-triacetylated-glucoside, 2-O-ß-D-(3',4',6'-tri-acetyl)-glucopyranosyl-3-methyl pentanoic acid was obtained from Ficus populifolia, and characterized through a detailed NMR spectroscopic analysis, i.e., 1H-NMR, 13C-DEPT-135, and the 2D nuclear magnetic resonance (NMR) correlations. The product was in silico investigated for its analgesic prowess, COX-2 binding feasibility and scores, drug likeliness, ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties, possible biosystem's toxicity using the Discovery Studio®, and other molecular studies computational software programs. The glycosidic product showed strong potential as an analgesic agent. However, an in vivo evaluation, though at strong levels of pain-relieving action, was estimated on the compound's extract owing to the quantity and yield issues of the glycosidic product. Nonetheless, the F. populifolia extract showed the analgesic potency in eight-week-old male mice on day seven of the administration of the extract's dose in acetic acid-induced writhing and hot-plate methods. Acetic acid-induced abdominal writhing for all the treated groups decreased significantly (p < 0.0001), as compared to the control group (n = 6) by 62.9%, 67.9%, and 70.9% of a dose of 100 mg/kg (n = 6), 200 mg/kg (n = 6), and 400 mg/kg (n = 6), respectively. Similarly, using the analgesia meter, the reaction time to pain sensation increased significantly (p < 0.0001), as compared to the control (n = 6). The findings indicated peripheral and central-nervous-system-mediated analgesic action of the product obtained from the corresponding extract.

Electrospun Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate)/Olive Leaf Extract Fiber Mesh as Prospective Bio-Based Scaffold for Wound Healing.

Polyhydroxyalkanoates (PHAs) are a family of biopolyesters synthesized by various microorganisms. Due to their biocompatibility and biodegradation, PHAs have been proposed for biomedical applications, including tissue engineering scaffolds. Olive leaf extract (OLE) can be obtained from agri-food biowaste and is a source of polyphenols with remarkable antioxidant properties. This study aimed at incorporating OLE inside poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) fibers via electrospinning to obtain bioactive bio-based blends that are useful in wound healing. PHBHV/OLE electrospun fibers with a size of 1.29 ± 0.34 µm were obtained. Fourier transform infrared chemical analysis showed a uniform surface distribution of hydrophilic -OH groups, confirming the presence of OLE in the electrospun fibers. The main OLE phenols were released from the fibers within 6 days. The biodegradation of the scaffolds in phosphate buffered saline was investigated, demonstrating an adequate stability in the presence of metalloproteinase 9 (MMP-9), an enzyme produced in chronic wounds. The scaffolds were preliminarily tested in vitro with HFFF2 fibroblasts and HaCaT keratinocytes, suggesting adequate cytocompatibility. PHBHV/OLE fiber meshes hold promising features for wound healing, including the treatment of ulcers, due to the long period of durability in an inflamed tissue environment and adequate cytocompatibility.

Nicotinamide Ameliorates Dextran Sulfate Sodium-Induced Chronic Colitis in Mice through Its Anti-Inflammatory Properties and Modulates the Gut Microbiota.

Vitamin B (nicotinamide (NAM)), one of the most important nutritional components for humans, exerts anti-inflammatory activity. This study was aimed at investigating the effect of NAM on the gut microbiota and short-chain fatty acids (SCFAs) in mice with chronic colitis. Colitis was induced in C57BL/6 male mice by administration of 1.5% dextran sulfate sodium (DSS), and the mice were intraperitoneally injected with normal saline (NS) or NAM. NAM treatment ameliorated weight loss and changes in colon length, disease activity index (DAI) score, and histologic scores. Moreover, enzyme-linked immunosorbent assay (ELISA) analysis of LPL cells revealed that the level of interleukin- (IL-) 6, IL-12p70, IL-1ß, tumor necrosis factor- (TNF-) α, interferon- (IFN-) γ, IL-21, and IL-17A was increased, while IL-10 was reduced, in the chronic colitis group compared to the control group, but the levels of all these factors were restored after NAM treatment. Then, 16S rRNA sequencing of the large intestinal content was performed, and analysis of alpha diversity and beta diversity showed that the richness of the gut microbiota was decreased in the DSS group compared to the control group and restored after NAM treatment. In addition, NAM modulated specific bacteria, including Odoribacter, Flexispira, and Bifidobacterium, in the NAM+chronic colitis group. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis indicated that NAM treatment restored disruptions in the functions of the gut microbiota (replication and repair, cell motility) in mice with DSS-induced colitis. Furthermore, NAM also restored the reduction in valeric acid in mice with DSS-induced chronic colitis. Our results suggest that NAM treatment could alleviate DSS-induced chronic colitis in mice by inhibiting inflammation and regulating the composition and function of gut microbiota.

Valerian and valeric acid inhibit growth of breast cancer cells possibly by mediating epigenetic modifications.

Valerian root (Valeriana officinalis) is a popular and widely available herbal supplement used to treat sleeping disorders and insomnia. The herb's ability to ameliorate sleep dysfunction may signify an unexplored anti-tumorigenic effect due to the connection between circadian factors and tumorigenesis. Of particular interest are the structural similarities shared between valeric acid, valerian's active chemical ingredient, and certain histone deacteylase (HDAC) inhibitors, which imply that valerian may play a role in epigenetic gene regulation. In this study, we tested the hypothesis that the circadian-related herb valerian can inhibit breast cancer cell growth and explored epigenetic changes associated with valeric acid treatment. Our results showed that aqueous valerian extract reduced growth of breast cancer cells. In addition, treatment of valeric acid was associated with decreased breast cancer cell proliferation, migration, colony formation and 3D formation in vitro in a dose- and time-dependent manner, as well as reduced HDAC activity and a global DNA hypomethylation. Overall, these findings demonstrate that valeric acid can decrease the breast cancer cell proliferation possibly by mediating epigenetic modifications such as the inhibition of histone deacetylases and alterations of DNA methylation. This study highlights a potential utility of valeric acid as a novel HDAC inhibitor and a therapeutic agent in the treatment of breast cancer.

Determination of the main naphthoquinones in Onosma hookeri Clarke. var. longiforum Duthie and its optimization of the ultrasound-assisted extraction using response surface methodology.

In this study, besides isovaleryl shikonin, another shikonin derivative, tigloylshikonin, was also isolated from the roots of Onosma hookeri Clarke. var. longiforum Duthie as a main naphthoquinone constituent for the first time. Then optimization of the ultrasonic-assisted extraction was done by Box-Behnken design-response surface methodology on the basis of single-factor experiments. The optimized conditions were 72% (v/v) ethanol and the material to solution ratio was 1:37(g/mL) at 52 °C for 77 min. Under these conditions, the extraction yield of ethanol extract was 36.74 ± 0.32%, the contents of isovaleryl shikonin and tigloylshikonin reached 0.094 ± 0.003% and 0.223 ± 0.006%, respectively. Notably, in that optimized condition, the yield of isovaleryl shikonin increased by approximately 7.64-fold than the previous report. In the in vitro antioxidant activity assay, the optimal ethanol extract exhibited similar 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity as butylated hydroxy toluene (BHT), but slightly weaker 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) scavenging activity and total antioxidant capacity than that of BHT. However, the active polar fraction, the ethyl acetate fraction, which is enriched with naphthoquinone constituents, performs as a better antioxidant agent than BHT. Therefore, both of them could be considered as a naturally sourced antioxidants compared to commercially available synthetic drugs. PRACTICAL APPLICATION: Onosma hookeri Clarke. var. longiforum Duthie, a traditional Chinese medicine and food item, has been in use since a long time. A systematic determination of the main naphthoquinones, and antioxidant capacity of the naphthoquinones-enriched ethanol extract and different polar fractions, was carried out in the present study. The results may provide theoretical basis for the claim that naphthoquinones-enriched ethanol extract and ethyl acetate fraction from the roots of Onosma hookeri Clarke. var. longiforum Duthie could be used as potential natural antioxidants in the pharmaceutical, food, and cosmetic industries.

Secretory Phospholipase A2 Inhibition Attenuates Adhesive Properties of Esophageal Barrett's Cells.

BACKGROUND: Gastroesophageal reflux and Barrett's esophagus are significant risk factors for the development of esophageal adenocarcinoma. Group IIa secretory phospholipase A2 (sPLA2) catalyzes the production of various proinflammatory metabolites and plays a critical role in promoting reflux-induced inflammatory changes within the distal esophagus. We hypothesized that inhibition of sPLA2 in human Barrett's cells would attenuate adhesion molecule expression via decreased activation of nuclear factor kappa B (NF-κB) and decrease cell proliferation, possibly mitigating the invasive potential of Barrett's esophagus. MATERIALS AND METHODS: Normal human esophageal epithelial cells (HET1A) and Barrett's cells (CPB) were assayed for baseline sPLA2 expression. CPB cells were treated with a specific inhibitor of sPLA2 followed by tumor necrosis factor-α. Protein expression was evaluated using immunoblotting. Cell proliferation was assessed using an MTS cell proliferation assay kit. Statistical analysis was performed using the Student's t-test or analysis of variance, where appropriate. RESULTS: CPB cells demonstrated higher baseline sPLA2 expression than HET1A cells (P = 0.0005). Treatment with 30 µM sPLA2 inhibitor significantly attenuated intercellular adhesion molecule-1 (P = 0.004) and vascular cell adhesion molecule-1 (P < 0.0001) expression as well as decreased NF-κB activation (P = 0.002). sPLA2 inhibition decreased cell proliferation in a dose-dependent manner (P < 0.001 for 15, 20, and 30 µM doses). CONCLUSIONS: sPLA2 inhibition in human Barrett's cells decreases cellular adhesive properties and NF-κB activation as well as decreases cell proliferation, signifying downregulation of the inflammatory response and possible attenuation of cellular malignant potential. These findings identify sPLA2 inhibition as a potential chemopreventive target for premalignant lesions of the esophagus.

Comparison of Chemical Composition between Kuromoji (Lindera umbellata) Essential Oil and Hydrosol and Determination of the Deodorizing Effect.

Kuromoji (Lindera umbellata) is a tree that grows throughout Japan. The components of kuromoji essential oil have antitumor and aromatherapy effects. However, the composition of the hydrosol, obtained as a by-product of the essential oil process, is unknown. Furthermore, it is unknown whether kuromoji essential oil has a deodorizing effect. Therefore, the purpose of the current study was to compare the chemical composition of kuromoji essential oil and hydrosol, as well as evaluate the deodorizing effect of the former. The chemical composition of samples was evaluated using gas chromatography-mass spectrometry (GC-MS). Additionally, the deodorizing effect of Kuromoji essential oil was investigated with the detector tube method using ammonia, hydrogen sulfide, methyl mercaptan, and isovaleric acid. Linalool was the most abundant component in both the essential oil and hydrosol; however, its proportion was higher in the hydrosol (57.5%) than in the essential oil (42.8%). The hydrosol contained fewer chemical components, but higher proportions of trans-geraniol and ethanol. Moreover, the essential oil eliminated 50% of ammonia and 97.6% or more of isovaleric acid. Interestingly, linalool was soluble in the hydrosol and did not irritate the skin. This suggests that the hydrosol may be an effective foot care product.

The knowns and unknowns of treatment for alcoholic hepatitis.

Alcoholic hepatitis is an acute, inflammatory liver disease associated with high morbidity and mortality both in the short term and long term. Alcoholic hepatitis often arises in patients with a background of chronic liver disease and it is characterised by the rapid onset of jaundice and the development of myriad complications. Medical therapy for severe alcoholic hepatitis relies on corticosteroids, which have modest effectiveness. Abstinence from alcohol is critically important in patients with alcoholic hepatitis, but recidivism is high. Because of the absence of effective medical treatments for alcoholic hepatitis and alcohol dependency, there is a pressing need to develop new and effective therapeutics. Supported by promising preliminary and preclinical studies, many ongoing clinical trials of new therapies for alcoholic hepatitis are currently underway and are discussed further in this Series paper.

Impact of Steviol Glycosides and Erythritol on the Human and Cebus apella Gut Microbiome.

Leaf extracts of Stevia rebaudiana, composed of more than 10 steviol glycosides (SGs), are used as non-nutritive, table sugar (sucrose) alternatives due to their high level of sweetness and low caloric impact. They are often combined with the sugar alcohol erythritol to increase volume and reduce aftertaste. Little is known of the impact of sugar alternatives on the human gut microbiota in terms of the diversity, composition, and metabolic products. Testing of SGs and erythritol using six representatives of the gut microbiota in vitro found no impact on bacterial growth, yet treatment with erythritol resulted in an enhancement of butyric and pentanoic acid production when tested using a human gut microbial community. Furthermore, administration of SGs and erythritol to a Cebus apella model resulted in changes to the gut microbial structure and diversity. Overall, the study did not find a negative impact of SGs and erythritol on the gut microbial community.

Profiling Vaccinium macrocarpon components and metabolites in human urine and the urine ex-vivo effect on Candida albicans adhesion and biofilm-formation.

The aim of this work was to profile, by using an HPLC-MS/MS method, cranberry compounds and metabolites found in human urine after ingestion of a highly standardized cranberry extract (Anthocran®). Two different strategies were adopted for the data analysis: a targeted and an untargeted approach. These strategies allowed the identification of 42 analytes including cranberry components, known metabolites and metabolites hitherto unreported in the literature, including six valerolactones/valeric acid derivatives whose presence in urine after cranberry consumption has never been described before. Absolute concentrations of 26 over 42 metabolites were obtained by using pure available standards. Urine collected at different time points after the last dosage of Anthocran® were tested on the reference strain C. albicans SC5314, a biofilm-forming strain. Fractions collected after 12 h were found to significantly reduce the adhesion and biofilm formation compared to the control (p < 0.05). A similar effect was then obtained by using Anthocran™ Phytosome™, the lecithin formulation containing 1/3 of standardized cranberry extract and formulated to enhance the absorption of the cranberry components. The urinary profile of cranberry components and metabolites in the urine fractions collected at 1 h, 6 h and 12 h after the last capsule intake were then reproduced by using the pure standards at the concentration ranges found in the urine fraction, and tested on C. albicans. Only the mixture mimicking the urinary fraction collected at 12 h and containing as main components, quercetin and 5-(3',4'-dihydroxyphenyl)-γ-valerolactone was found effective thus confirming the ex-vivo results.

Tussilagonone Ameliorates Psoriatic Features in Keratinocytes and Imiquimod-Induced Psoriasis-Like Lesions in Mice via NRF2 Activation.

Psoriasis is a common inflammatory skin disorder that is characterized by keratinocyte hyperproliferation and abnormal differentiation, resulting in the thickening of the epidermis and stratum corneum. In this study, we investigated in vitro and in vivo pharmacological effects of tussilagonone (TGN), a sesquiterpenoid isolated from Tussilago farfara, on transcription factors relevant for the pathogenesis of psoriasis. TGN inhibited activation of NF-κB and STAT3, leading to the attenuated expression of psoriasis-related inflammatory genes and suppression of keratinocyte hyperproliferation. Mechanistically, we show that the inhibition of NF-κB and STAT3 by TGN is mediated through activation of the cytoprotective transcription factor NRF2. Evaluation of in vivo antipsoriatic effects of topical TGN in the imiquimod-induced psoriasis-like dermatitis mouse model demonstrated amelioration of imiquimod-induced phenotypical changes, lesion severity score, epidermal thickening, and reduction in dermal cellularity. The spleen index also diminished in TGN-treated mice, suggesting anti-inflammatory properties of TGN. Moreover, TGN significantly attenuated the imiquimod-induced mRNA levels of psoriasis-associated inflammatory cytokines and antimicrobial peptides and reduced epidermal hyperproliferation. Taken together, TGN, as a potent NRF2 activator, is a promising therapeutic candidate for the development of antipsoriatic agents derived from medicinal plants.

5-(Hydroxyphenyl)-γ-Valerolactone-Sulfate, a Key Microbial Metabolite of Flavan-3-ols, Is Able to Reach the Brain: Evidence from Different in Silico, In Vitro and In Vivo Experimental Models.

Phenolic compounds have been recognized as promising compounds for the prevention of chronic diseases, including neurodegenerative ones. However, phenolics like flavan-3-ols (F3O) are poorly absorbed along the gastrointestinal tract and structurally rearranged by gut microbiota, yielding smaller and more polar metabolites like phenyl-γ-valerolactones, phenylvaleric acids and their conjugates. The present work investigated the ability of F3O-derived metabolites to cross the blood-brain barrier (BBB), by linking five experimental models with increasing realism. First, an in silico study examined the physical-chemical characteristics of F3O metabolites to predict those most likely to cross the BBB. Some of these metabolites were then tested at physiological concentrations to cross the luminal and abluminal membranes of brain microvascular endothelial cells, cultured in vitro. Finally, three different in vivo studies in rats injected with pure 5-(3',4'-dihydroxyphenyl)-γ-valerolactone, and rats and pigs fed grapes or a F3O-rich cocoa extract, respectively, confirmed the presence of 5-(hydroxyphenyl)-γ-valerolactone-sulfate (3',4' isomer) in the brain. This work highlighted, with different experimental models, the BBB permeability of one of the main F3O-derived metabolites. It may support the neuroprotective effects of phenolic-rich foods in the frame of the "gut-brain axis".

Isovaleric acid and avicequinone-C are Chikungunya virus resistance principles in Glycosmis pentaphylla (Retz.) Correa.

BACKGROUND & OBJECTIVES: Oral administration of tender leaf extract of Glycosmis pentaphylla is traditionally known to prevent the chikungunya virus infection. Even with wide usage, the antiviral components in this plant are neither identified nor characterized. This study was carried out with the objectives of profiling the phytocompounds in this plant through LC-MS/MS and to identify the active antiviral constituents and their drug-likeliness through molecular docking. METHODS: Phytocompounds were extracted hydro-alcoholically from powdered plant parts and analyzed using LC-MS/MS. Based on mass-to-charge ratio from LC-MS/MS, compounds were identified and used as ligands for molecular docking against chikungunya target proteins. The active principles were subjected to ADME/T analysis to verify their drug-likeliness. RESULTS: The docking results and ADME/T evaluation showed that the compounds, isovaleric acid and avicequinone- C have good interaction with the protein targets and hence could be the antiviral principles of the selected plant. These compounds presented acceptable drug properties and hence could be carried forward to in vivo studies for drug development. INTERPRETATION & CONCLUSION: The antiviral properties of G. pentaphylla are known since time-immemorial. This study revealed the probable interactions after the oral administration of tender leaves of Glycosmis in preventing the chikungunya virus infection and paves the path for designing future plant-based drugs.

Mesenchymal Stem Cell Capping on ECM-Anchored Caspase Inhibitor-Loaded PLGA Microspheres for Intraperitoneal Injection in DSS-Induced Murine Colitis.

Mesenchymal stem cells (MSCs) are considered as a promising alternative for the treatment of various inflammatory disorders. However, poor viability and engraftment of MSCs after transplantation are major hurdles in mesenchymal stem cell therapy. Extracellular matrix (ECM)-coated scaffolds provide better cell attachment and mechanical support for MSCs after transplantation. A single-step method for ECM functionalization on poly(lactic-co-glycolic acid) (PLGA) microspheres using a novel compound, dopamine-conjugated poly(ethylene-alt-maleic acid), as a stabilizer during the preparation of microspheres is reported. The dopamine molecules on the surface of microspheres provide active sites for the conjugation of ECM in an aqueous solution. The results reveal that the viability of MSCs improves when they are coated over the ECM-functionalized PLGA microspheres (eMs). In addition, the incorporation of a broad-spectrum caspase inhibitor (IDN6556) into the eMs synergistically increases the viability of MSCs under in vitro conditions. Intraperitoneal injection of the MSC-microsphere hybrid alleviates experimental colitis in a murine model via inhibiting Th1 and Th17 differentiation of CD4+ T cells in colon-draining mesenteric lymph nodes. Therefore, drug-loaded ECM-coated surfaces may be considered as attractive tools for improving viability, proliferation, and functionality of MSCs following transplantation.

Monovalerin and trivalerin increase brain acetic acid, decrease liver succinic acid, and alter gut microbiota in rats fed high-fat diets.

PURPOSE: Short-chain fatty acids (SCFA) are known for their anti-inflammatory properties and may also prevent against the development of metabolic diseases. This study investigated possible effects of two valeric acid esters, monovalerin (MV) and trivalerin (TV) in rats fed high-fat diets. METHODS: Four groups of rats were given a low-fat diet (LF) or a high-fat control diet (HFC) with or without supplementation of MV or TV (5 g/kg) for 3 weeks (n = 7/group). SCFA (caecum, blood, liver and brain), succinic acid (liver), microbiota (caecum), lipid profile (liver and blood) and the inflammatory biomarker, lipopolysaccharide-binding protein (blood) were analysed at the end of the experiment. RESULTS: Supplementation of MV and TV to a high-fat diet increased 1.5-fold the amounts of acetic acid in the brain and 1.7-fold serum concentration of valeric acid, whereas liver succinic acid was reduced by 1.5-fold. Although liver triglyceride levels were higher in both MV and TV groups compared with the LF group, liver LDL/HDL ratio was lower in the MV group (P < 0.05). The caecal microbiota composition was altered, with threefold higher abundance of Bacteroidetes and higher ratio of Bacteroidetes/Firmicutes in the MV group compared with the HFC and LF groups. Acetic acid in the brain was negatively correlated with TM7, family S24-7 and rc4-4, and positively associated to Tenericutes and Anaeroplasma. CONCLUSIONS: The present study shows that MV and TV in the specified dose can affect caecal microbiota composition and, therefore, bacterial metabolites in the liver, serum and brain as well as the lipid profile in the liver.

Isovalerylshikonin, a new resistance-modifying agent from Arnebia euchroma, supresses antimicrobial resistance of drug-resistant Staphylococcus aureus.

Antimicrobial resistance is the greatest threat to the treatment of bacterial infectious diseases. The development of resistance-modifying agents (RMAs) represents a promising strategy to mitigate the spread of bacterial antimicrobial resistance. In this study, a natural product, isovalerylshikonin (IVS), was isolated from Arnebia euchroma, a traditional Chinese medicine herb, that exhibited marginal antibacterial activity against drug-resistant Staphylococcus aureus RN4220, with a minimum inhibitory concentration (MIC) of 16 mg/L. In addition, a synergistic effect between IVS and streptomycin (STM) was detected by the microdilution antimicrobial chequerboard assay, with a reduction in the MIC of STM by up to 16-fold against strain RN4220. A bacterial ethidium bromide efflux assay and reverse transcription PCR were performed to investigate the synergistic mechanism. IVS significantly inhibited bacterial efflux and expression of msrA mRNA in vitro. A murine peritonitis/sepsis model was employed to test the in vivo synergistic activity of IVS and STM. IVS synergistically decreased bacterial counts with STM in peritoneal, spleen and liver tissue and increased mouse survival with STM in 7 days. The acute toxicity of IVS was tested and the 50% lethal dose (LD50) of IVS with a single exposure was 2.584 g/kg in mice. Overall, IVS, a low-toxicity RMA, exhibited synergistic antibacterial activities in vitro and in vivo against drug-resistant S. aureus. The effects were mediated by suppression of msrA mRNA expression and reduced bacterial efflux. In addition, these data support that IVS is a potential RMA against microbial resistance caused by the MsrA efflux pump.

Ancient and modern anticonvulsants act synergistically in a KCNQ potassium channel binding pocket.

Epilepsy has been treated for centuries with herbal remedies, including leaves of the African shrub Mallotus oppositifolius, yet the underlying molecular mechanisms have remained unclear. Voltage-gated potassium channel isoforms KCNQ2-5, predominantly KCNQ2/3 heteromers, underlie the neuronal M-current, which suppresses neuronal excitability, protecting against seizures. Here, in silico docking, mutagenesis and cellular electrophysiology reveal that two components of M. oppositifolius leaf extract, mallotoxin (MTX) and isovaleric acid (IVA), act synergistically to open neuronal KCNQs, including KCNQ2/3 channels. Correspondingly, MTX and IVA combine to suppress pentylene tetrazole-induced tonic seizures in mice, whereas individually they are ineffective. Co-administering MTX and IVA with the modern, synthetic anticonvulsant retigabine creates a further synergy that voltage independently locks KCNQ2/3 open. Leveraging this synergy, which harnesses ancient and modern medicines to exploit differential KCNQ isoform preferences, presents an approach to developing safe yet effective anticonvulsants.

Effects of isovalerate supplements on morphology and functional gene expression of rumen mucosa in pre- and post-weaning dairy calves.

Isovalerate supplements could stimulate rumen development by improving morphology and function of rumen mucosa, and then promote the growth of calves. This study was done to evaluate the effects of isovalerate supplements on morphology and functional gene expression of rumen mucosa in dairy calves. In total, 48 Chinese Holstein male calves with 15 days of age and 45.1±0.36 kg of BW were randomly assigned to four groups. The treatments were: control, low-isovalerate, moderate-isovalerate and high-isovalerate with 0, 3, 6 and 9 g isovalerate per calf per day, respectively. Supplementary isovalerate was hand-mixed into milk in pre-weaning calves and into concentrate portion in post-weaning calves. The study consisted of a 15-day-adaptation period and a 60-day-sampling period. Calves were weaned at 60 days of age. Three calves were slaughtered from each of the four treatments at 30, 60 and 90 days of age. The weight of body and stomach were measured, samples of ruminal tissues and blood were analyzed. Total stomach weight, total stomach to BW ratio, rumen wall and keratinized layer thickness, serum growth hormone and IGF-1 for both pre- and post-weaning calves increased linearly with increasing isovalerate supplements. Rumen to total stomach weight ratio, the length and width of rumen papillae, and serum ß-hydroxybutyrate increased linearly for post-weaning calves. However, abomasum weight to total stomach weight ratio decreased linearly for both pre- and post-weaning calves. The relative messenger RNA expression for growth hormone receptor, IGF-1 receptor and 3-hydroxy-3-methylglutaryl-CoA synthase 1 in rumen mucosa increased linearly for post-weaning calves. Our results suggested that isovalerate supplements promoted rumen development in a dose-dependent manner. The optimum dose was 6.0 g isovalerate per calf per day.

The antiadhesive activity of cranberry phytocomplex studied by metabolomics: Intestinal PAC-A metabolites but not intact PAC-A are identified as markers in active urines against uropathogenic Escherichia coli.

Cranberry procyanidins and quercetin derivatives are considered possible active compounds against urinary tract infections (UTIs). In this paper a small group (n=6) of healthy subjects consumed a product containing 360mg of cranberry extract (42.6% w/w of PAC-A and 14.6% w/w of PAC-B) and 200mg of quercetin. Urine samples were collected after 2,4,6,8, and 24h. The changes in antiadhesive properties against urophatogenic E. coli of the urinary output were determined in vitro and modification to urinary metabolome were studied by LC-MS. Significant antiadhesive properties of urine samples were observed, with the greatest effect 6-8h after oral administration, confirming the possible usefulness of cranberry containing products in urinary tract infections (UTI). Metabolomic analysis revealed that valeric acid and valerolactone derivatives that were detected in 6 and 8h sample, while 4-hydroxy-5-(phenyl)-valeric acid-O-glucuronide and 5-(3',4'-dihydroxyphenyl)-γ-valerolactone at 6h and 4-hydroxy-5-(phenyl)-valeric acid-O-sulphate, 3-hydroxyphenyl-valeric acid, 5-(4'-hydroxyphenyl)-gamma-valerolactone-4'-O-glucuronide and 4-hydroxy-5-(3'-hydroxyphenyl)-valeric acid-3'-O-sulphate were the most abundant at 8h. The present study shows that the antiadhesive properties of urine sample after cranberry consumption are not ascribable to the direct effect of PAC-A, because their levels in urinary output are in the range of ng/mL. On the other hand, significant metabolites that were detected are mainly metabolites of intestinal action on polyphenols and PACs, as well as glucuronidated and sulphated quercetin, suggesting an important role of intestinal modification of phytoconstituents in the cranberry extract mechanism of action.