Biological Activities of Citrus aurantium Leaf Extract by Optimized Ultrasound-Assisted Extraction.

Several studies have explored the biological activities of Citrus aurantium flowers, fruits, and seeds, but the bioactivity of C. aurantium leaves, which are treated as waste, remains unclear. Thus, this study developed a pilot-scale ultrasonic-assisted extraction process using the Box-Behnken design (BBD) for the optimized extraction of active compounds from C. aurantium leaves, and their antityrosinase, antioxidant, antiaging, and antimicrobial activities were evaluated. Under optimal conditions in a 150× scaleup configuration (a 30 L ultrasonic machine) of a pilot plant, the total phenolic content was 69.09 mg gallic acid equivalent/g dry weight, which was slightly lower (3.17%) than the theoretical value. The half maximal inhibitory concentration of C. aurantium leaf extract (CALE) for 2,2-diphenyl-1-picrylhydrazyl-scavenging, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)-scavenging, antityrosinase, anticollagenase, antielastase and anti-matrix metalloprotein-1 activities were 123.5, 58.5, 181.3, 196.4, 216.3, and 326.4 mg/L, respectively. Moreover, the minimal inhibitory concentrations for bacteria and fungi were 150-350 and 500 mg/L, respectively. In total, 17 active compounds were detected in CALE-with linalool, linalyl acetate, limonene, and α-terpineol having the highest concentrations. Finally, the overall transdermal absorption and permeation efficiency of CALE was 95.9%. In conclusion, our CALE demonstrated potential whitening, antioxidant, antiaging, and antimicrobial activities; it was also nontoxic and easily absorbed into the skin as well as inexpensive to produce. Therefore, it has potential applications in various industries.

Improving the practicality of recombinant Escherichia coli biosensor in detecting trace Cr(VI) by modifying the cryogenic storage conditions of biosensors and applying simple pretreatment.

Hexavalent chromium (Cr(VI)) is a global environmental pollutant. To reduce the risk caused by Cr(VI), a simple, accurate, reproducible, and inexpensive method for quantifying Cr(VI) in water and soil should be developed. In this study, three types of recombinant Escherichia coli biosensors (namely T7-lux-E. coli, T3-lux-E. coli, and SP6-lux-E. coli biosensor) containing promoters (T7, T3, and SP6), chromate-sensing regulator chrB, and the reporter gene luxAB were constructed. This study investigated the effects of cryogenic freezing temperature and time on trace Cr(VI) measurement by using recombinant E. coli biosensors. The results indicated that the activity of thawed frozen SP6-lux-E. coli cells stored at -20 °C for 270 days did not differ from that of freshly prepared cells. Turbidity and conductivity in water samples and organic matter in soil interfered with Cr(VI) measurement using the biosensor. The SP6-lux-E. coli biosensor exhibited a wide measurement range and a low deviation of <5% for measuring Cr(VI) in various Cr(VI)-contaminated water and soil samples and required only a simple pretreatment or extraction process even after 270-day storage at -20 °C. To the best of our knowledge, this is the first study to report the use of recombinant biosensors for accurately measuring Cr(VI) in both water and soil.

Characterization of Tibetan kefir grain-fermented milk whey and its suppression of melanin synthesis.

Tibetan kefir grain as the starter of milk fermentation has been applied as functional food with many bioactive characteristics. In this study, the milk whey product (TKG-MW) was obtained through the milk fermentation of Tibetan kefir grain containing the dominant Lactobacillus, Acetobacter, and Bacillus after 3 and 6 days of cultivation. Antioxidant, anti-inflammatory, and melanogenesis inhibition capacities under TKG-MW treatment were analyzed. Results revealed that the antioxidation of TKG-MW at 6 days of fermentation was higher than that at 3 days of fermentation according to the DPPH and ABTS+ radical scavenging analysis. However, the anti-inflammation of TKG-MW was only observed at 6 days of fermentation by using lipopolysaccharide-stimulated RAW 264.7 macrophages. The inhibition of mushroom tyrosinase activity by TKG-MW was demonstrated. The decrease of melanin content was verified using α-melanocyte-stimulating hormone-stimulated B16-F10 cell. The real-time quantitative reverse transcription polymerase chain reaction result indicated that the mRNA levels of Tyr, Trp-1, and Trp-2 of the B16 cell involved in melanin synthesis were down-regulated over a two-fold change by the TKG-MW treatment. Additionally, the protein expressions of Tyr, Trp-1, Trp-2, and Mitf of the B16 cell were reduced with the TKG-MW treatment. Organic acids, such as lactic acid, succinic acid, 3-phenyllactic acid, l-pyroglutamic acid, and malic acid, were identified by liquid chromatography-mass spectrometry in TKG-MW and were found to significantly inhibit tyrosinase activity. To the best of our knowledge, this work is the first to report melanogenesis suppression by TKG-MW. Results suggested that the fermentation product of TKG could be applied as a depigmenting agent in food and cosmetics.

Highly Sensitive Luminescent Bioassay Using Recombinant Escherichia coli Biosensor for Rapid Detection of Low Cr(VI) Concentration in Environmental Water.

In this study, we constructed a recombinant Escherichia coli strain with different promoters inserted between the chromate-sensing regulator chrB and the reporter gene luxAB to sense low hexavalent chromium (Cr(VI)) concentrations (<0.05 mg/L); subsequently, its biosensor characteristics (sensitivity, selectivity, and specificity) for measuring Cr(VI) in various water bodies were evaluated. The luminescence intensity of each biosensor depended on pH, temperature, detection time, coexisting carbon source, coexisting ion, Cr(VI) oxyanion form, Cr(VI) concentration, cell type, and type of medium. Recombinant lux-expressing E. coli with the T7 promoter (T7-lux-E. coli, limit of detection (LOD) = 0.0005 mg/L) had the highest luminescence intensity or was the most sensitive for Cr(VI) detection, followed by E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.001 mg/L) and that with the SP6 promoter (SP6-lux-E. coli, LOD = 0.005 mg/L). All biosensors could be used to determine whether the Cr(VI) standard was met in terms of water quality, even when using thawing frozen cells as biosensors after 90-day cryogenic storage. The SP6-lux-E. coli biosensor had the shortest detection time (0.5 h) and the highest adaptability to environmental interference. The T7-lux-E. coli biosensor-with the optimal LOD, a wide measurement range (0.0005-0.5 mg/L), and low deviation (-5.0-7.9%) in detecting Cr(VI) from industrial effluents, domestic effluents, and surface water-is an efficient Cr(VI) biosensor. This unprecedented study is to evaluate recombinant lux E. coli with dissimilar promoters for their possible practice in Cr(VI) measurement in water bodies, and the biosensor performance is clearly superior to that of past systems in terms of detection time, LOD, and detection deviation for real water samples.

Analysis of bioavailable toluene by using recombinant luminescent bacterial biosensors with different promoters.

In this study, we constructed recombinant luminescent Escherichia coli with T7, T3, and SP6 promoters inserted between tol and lux genes as toluene biosensors and evaluated their sensitivity, selectivity, and specificity for measuring bioavailable toluene in groundwater and river water. The luminescence intensity of each biosensor depended on temperature, incubation time, ionic strength, and concentrations of toluene and coexisting organic compounds. Toluene induced the highest luminescence intensity in recombinant lux-expressing E. coli with the T7 promoter [T7-lux-E. coli, limit of detection (LOD) = 0.05 µM], followed by that in E. coli with the T3 promoter (T3-lux-E. coli, LOD = 0.2 µM) and SP6 promoter (SP6-lux-E. coli, LOD = 0.5 µM). Luminescence may have been synergistically or antagonistically affected by coexisting organic compounds other than toluene; nevertheless, low concentrations of benzoate and toluene analogs had no such effect. In reproducibility experiments, the biosensors had low relative standard deviation (4.3-5.8%). SP6-lux-E. coli demonstrated high adaptability to environmental interference. T7-lux-E. coli biosensor-with low LOD, wide measurement range (0.05-500 µM), and acceptable deviation (- 14.3 to 9.1%)-is an efficient toluene biosensor. This is the first study evaluating recombinant lux E. coli with different promoters for their potential application in toluene measurement in actual water bodies.

Removal of toluene vapor in the absence and presence of a quorum-sensing molecule in a biotrickling filter and microbial composition shift.

Toluene is highly toxic and mutagenic, and it is generally used as an industrial solvent. Thus, toluene removal from air is necessary. To solve the problem of reducing high toluene concentrations with a short gas retention time (GRT), a quorum-sensing molecule [N-(3-oxododecanoyl)-L-homoserine lactone] (OHL) was added to a biotrickling filter (BTF). In this study, a BTF was used to treat synthetic and natural waste gases containing toluene. An extensive analysis was performed to understand the removal efficiency, removal characteristics, and bacterial community of the BTF. The addition of 20 µM OHL to the BTF significantly improved toluene removal, and more than 99.2% toluene removal was achieved at a GRT of 0.5 min when natural waste gas containing toluene (590-1020 ppm or 2.21-3.83 g m-3) was introduced. The maximum inlet load for toluene was 337.9 g m-3 h-1. Moreover, the BTF exhibited satisfactory adaptability to shock loading and shutdown operations. Pseudomonadaceae (33.0%) and Comamonadaceae (26.3%) were predominant bacteria in the system after a 98-day operation. These bacteria were responsible for toluene degradation. The optimal moisture content and low pressure drop for system operations demonstrated that the BTF was energy and cost efficient. Therefore, processing through a BTF with OHL is a favorable technique for toluene treatment.

Evaluation of synthetic gene encoding α-galactosidase through metagenomic sequencing of paddy soil.

Many genes of industrial relevance can be found in soil. In this study, metagenome sequencing of paddy soil was performed with 55.68 Gb sequences and 1,787,113 putative open reading frames (ORFs). The functional profiles and metabolic pathway of soil metagenomes were examined using Gene Ontology, Metagenomics RAST, and Kyoto Encyclopedia of Genes and Genomes. To verify the protein function and assembly of ORFs, a putative gene encoding α-galactosidase, namely GalR, which shares 65% identity with an unpublished glycoside hydrolase (GH) 27 family protein, was synthesized using its optimal codon for overexpression in Escherichia coli. GalR was successfully obtained and characterized. The optimal temperature and pH for GalR activity were 30°C and pH 9, respectively. Enzymatic activity indicated that GalR was alkaliphilic and different from acidophilic α-galactosidase in the GH 27 family. Furthermore, 50% of the relative activity of GalR can be attained for 1.7 and 0.7 h preincubation at 40°C and 50°C, respectively. Significant inhibition of GalR was observed in the presence of ethylenediaminetetraacetic acid (EDTA), MgCl2, sodium dodecyl sulfate (SDS), and H2O2; however, it was resistant to 0.1% methanol and ethanol and was slightly activated with NaCl and KCl. The specific activity of GalR was achieved at 11.6 and 0.59 µmol/min/mg of protein using p-nitrophenyl-α-d-galactopyranoside and raffinose as substrates, respectively. Consequently, the metagenomic sequencing-based strategy can provide information for mining novel genes.

Anticandidal Potential of Stem Bark Extract from Schima superba and the Identification of Its Major Anticandidal Compound.

Plant-derived extracts are a promising source of new drugs. Schima superba is traditionally used in China for heat clearing, detoxification, and treatment of furuncles. In this study, the anticandidal properties and mechanism of action of S. superba (SSE) were explored using a stem bark extract. SSE possessed high polyphenol and saponin contents of 256.6 ± 5.1 and 357.8 ± 31.5 µg/mg, respectively. A clear inhibition zone was observed for C. albicans growth through the disc diffusion method and the 50% inhibition of C. albicans by SSE was 415.2 µg/mL. Transcriptomic analysis in C. albicans treated with different doses of SSE was conducted through RNA-seq. Average values of 6068 genes and 20,842,500 clean reads were identified from each sample. Among these samples, 1680 and 1956 genes were differentially expressed genes (DEGs) from the SSE treatments of 0.2 and 0.4 mg/mL, respectively. C. albicans growth was inhibited by the changes in gene expression associated with the cell wall and membrane composition including the regulation of chitin degradation and ergosterol biosynthesis. This result could be reflected in the irregularly wrinkled morphology of the ruptured cell as revealed through SEM analysis. ESI-MS and NMR analyses revealed that the major compound purified from SSE was sasanquasaponin III and the 50% inhibition of C. albicans was 93.1 µg/mL. In summary, the traditional Chinese medicine S. superba can be applied as an anticandidal agent in complementary and alternative medicine.

Three-Stage Single-Chambered Microbial Fuel Cell Biosensor Inoculated with Exiguobacterium aestuarii YC211 for Continuous Chromium (VI) Measurement.

Chromium (VI) [Cr(VI)] compounds display high toxic, mutagenic, and carcinogenic potential. Biological analysis techniques (e.g., such as enzyme-based or cell-based sensors) have been developed to measure Cr(VI); however, these biological elements are sensitive to the environment, limited to measuring trace Cr(VI), and require deployment offsite. In this study, a three-stage single-chambered microbial fuel cell (SCMFC) biosensor inoculated with Exiguobacterium aestuarii YC211 was developed for in situ, real-time, and continuous Cr(VI) measurement. A negative linear relationship was observed between the Cr(VI) concentration (5⁻30 mg/L) and the voltage output using an SCMFC at 2-min liquid retention time. The theoretical Cr(VI) measurement range of the system could be extended to 5⁻90 mg/L by connecting three separate SCMFCs in series. The three-stage SCMFC biosensor could accurately measure Cr(VI) concentrations in actual tannery wastewater with low deviations (<7%). After treating the wastewater with the SCMFC, the original inoculated E. aestuarii remained dominant (>92.5%), according to the next-generation sequencing analysis. The stable bacterial community present in the SCMFC favored the reliable performance of the SCMFC biosensor. Thus, the three-stage SCMFC biosensor has potential as an early warning device with wide dynamic range for in situ, real-time, and continuous Cr(VI) measurement of tannery wastewater.

Comparison of biofunctional activity of Asparagus cochinchinensis (Lour.) Merr. Extract before and after fermentation with Aspergillus oryzae.

Asparagus cochinchinensis root (ACR) is used in traditional Chinese medicine. In this study, ACR was first extracted with 25% ethyl acetate (EA) and then fermented by Aspergillus oryzae to enhance its antioxidant activity and evaluate its potential antityrosinase activity. The physiological activity and cytotoxicity of A. oryzae-fermented ACR extract, along with its antityrosinase activity and effects on melanogenic factor levels in human epidermal melanocytes (HEMs), were analyzed and compared with those of the unfermented extract. The results showed that the physiological activity of the fermented extract in vitro or in cells was significantly higher than that of the unfermented extract. The IC50 values for 2,2-diphenyl-1-picrylhydrazine radical scavenging activity, reducing power, and antityrosinase activity in vitro for the fermented extract were 250.6 ± 32.5, 25.7 ± 3.5, and 50.6 ± 3.1 mg/L, respectively. The fermented extract favored cellular antityrosinase activity with low melanin production in human melanoma cells compared with the unfermented extract. The inhibitory mechanism of melanin synthesis by unfermented extract was independent of the tested melanogenesis-related proteins. However, the inhibitory mechanism of the fermented extract was possibly caused by synergistic inhibition of these proteins. Thus, A. oryzae-fermented ACR extract may be used for developing new health food or cosmetic ingredients.

Inspecting the genome sequence and agarases of Microbulbifer pacificus LD25 from a saltwater hot spring.

Neoagaro-oligosaccharides prepared by agar hydrolysis have various application fields, including the pharmaceutical, cosmetic, and food industries. In this study, an agarolytic strain was isolated from a saltwater hot spring and identified as Microbulbifer pacificus LD25 by 16S rRNA. The whole genome sequence of M. pacificus LD25 was obtained. It had a size of 4.27 Mb and comprised 3062 predicted genes in 37 contigs with a G+C content of 58.0%. Six agarases were annotated and classified into three families, namely, GH16 (AgaL1), GH86 (AgaL2, AgaL3), and GH50 (AgaL4, AgaL5, AgaL6), which shared 75-96% identities with unpublished hypothetical proteins and agarases. AgaL1, AgaL4, and AgaL6 can be successfully expressed and purified in Escherichia coli. AgaL1 and AgaL4 displayed a significantly agarolytic capability, whereas AgaL6 exhibited a rarely detectable enzymatic activity. The optimal temperature and pH required for the activity of AgaL1 and AgaL4 was 50°C and 60°C, respectively, at pH 7. The specific activities of AgaL1 and AgaL4 were achieved at 16.8 and 9.6 U per mg of protein. Both agarases were significantly inhibited in the presence of EDTA, MgO, ZnCl2, and H2O2. However, AgaL1 was resistant to 0.1% SDS and AgaL4 was slightly activated by CaCl2. Substrate hydrolysis detected by LC-MS/MS analysis indicated that neoagarobiose was the main product during AgaL1 and AgaL4 catalysis. Furthermore, AgaL4 was thermostable and retained over 93% of its relative activity after pre-incubation at 70°C for 180 min. Consequently, M. pacificus LD25 has a potential for agarase production in E. coli and industrial applications.

Antioxidant and anti-inflammatory capacities of collagen peptides from milkfish (Chanos chanos) scales.

Milkfish (Chanos chanos), which is resistant to water quality changes is the fourth largest aquaculture commodity. Abandoned wastes of fish scale and bones aggravate environmental pollution. In this study, the effect of collagen peptides isolated from milkfish scales (MSCP) by pepsin-soluble collagen method on cell viability was investigated. The antioxidant, anti-inflammatory, and DNA-protective activities of MSCP were also evaluated. Results revealed that more than 95% of viable cells were retained in human keratinocytes after addition of 100 mg/mL MSCP. Measurement of DPPH· and ABTS· + radical scavenging activities and cellular reactive oxygen species revealed the high antioxidant activities of MSCP. MSCP demonstrated anti-inflammatory activities by reducing lipoxygenase activity and nitric oxide (NO·) radicals. Moreover, DNA electrophoresis assay indicated that MSCP treatment can directly protect against cyclobutane di-pyrimidine production and DNA single-strand breaks, which are harmful effects of UV radiation and H2O2. Given its antioxidant, anti-inflammatory, and DNA-protective activities, MSCP has potential applications in cosmeceuticals and supplementary health food.

Arctigenin protects against steatosis in WRL68 hepatocytes through activation of phosphoinositide 3-kinase/protein kinase B and AMP-activated protein kinase pathways.

Arctigenin (ATG), a lignin extracted from Arctium lappa (L.), exerts antioxidant and anti-inflammatory effects. We hypothesized that ATG exerts a protective effect on hepatocytes by preventing nonalcoholic fatty liver disease (NAFLD) progression associated with lipid oxidation-associated lipotoxicity and inflammation. We established an in vitro NAFLD cell model by using normal WRL68 hepatocytes to investigate oleic acid (OA) accumulation and the potential bioactive role of ATG. The results revealed that ATG inhibited OA-induced lipid accumulation, lipid peroxidation, and inflammation in WRL68 hepatocytes, as determined using Oil Red O staining, thiobarbituric acid reactive substance assay, and inflammation antibody array assays. Quantitative RT-PCR analysis demonstrated that ATG significantly mitigated the expression of acetylcoenzyme A carboxylase 1 and sterol regulatory element-binding protein-1 and significantly increased the expression of carnitine palmitoyltransferase 1 and peroxisome proliferator-activated receptor alpha. The 40 targets of the Human Inflammation Antibody Array indicated that ATG significantly inhibited the elevation of the U937 lymphocyte chemoattractant, ICAM-1, IL-1ß, IL-6, IL-6sR, IL-7, and IL-8. ATG could activate the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and AMP-activated protein kinase (AMPK) pathways and could increase the phosphorylation levels of Akt and AMPK to mediate cell survival, lipid metabolism, oxidation stress, and inflammation. Thus, we demonstrated that ATG could inhibit NAFLD progression associated with lipid oxidation-associated lipotoxicity and inflammation, and we provided insights into the underlying mechanisms and revealed potential targets to enable a thorough understanding of NAFLD progression.

Continuous bioelectricity generation through treatment of Victoria blue R: A novel microbial fuel cell operation.

A novel two-chamber microbial fuel cell (MFC) operation with a continuous anaerobic-aerobic decolorization system was developed to improve the degradation of the triphenylmethane dye, Victoria blue R (VBR). In addition, bioelectricity was generated during the VBR degradation process, and the operation parameters were optimized. The results indicated that the VBR removal efficiency and electricity generation were affected by the VBR concentration, liquid retention time (LRT), external resistance, gas retention time (GRT), and shock loading. The optimal operation parameters were as follows: VBR concentration, 600 mg L-1; LRT, 24 h; external resistance, 3300 Ω; and GRT, 60 s. Under these operating conditions, the VBR removal efficiency, COD removal efficiency, and power density were 98.2% ± 0.3%, 97.6% ± 0.5%, and 30.6 ± 0.4 mW m-2, respectively. According to our review of the relevant literature, this is the first paper to analyze the electrical characteristics of a continuous two-chamber MFC operation and demonstrate the feasibility of the simultaneous electricity generation and decolorization of VBR.

Evaluation of tyrosinase inhibitory and antioxidant activities of Angelica dahurica root extracts for four different probiotic bacteria fermentations.

Angelica dahurica root (ADR), which shows strong antioxidant activity, is used in Chinese medicine. This study evaluated the tyrosinase inhibitory and antioxidant activities of ADR extracts fermented by four different probiotic bacteria: Bifidobacterium bifidum, Bifidobacterium lactis, Lactobacillus acidophilus, and Lactobacillus brevis. The ADR was first extracted using distilled water, 70% ethanol, and ethyl acetate, and then fermented by probiotic bacteria. The physiological characteristics of these fermented extracts, namely the antityrosinase activity, antioxidant activity, phenolic composition, and phenolic content, were evaluated and compared with those of unfermented extracts. Results showed that the water extracts after fermentation by probiotic bacteria exhibited the most favorable physiological characteristics. Among the extracts fermented by these probiotic bacteria, L. acidophilus-fermented ADR extract showed the most favorable physiological characteristics. The optimal IC50 values for antityrosinase activity, DPPH radical scavenging activity, and reducing power for L. acidophilus-fermented ADR extract were 0.07 ± 0.03, 0.12 ± 0.01, and 0.68 ± 0.06 mg/mL, respectively. Furthermore, the physiological activities of fermented extracts were considerably higher than those of unfermented extracts. The tyrosinase inhibition and melanin content of B16F10 melanoma cells, and cytotoxicity effects of the fermented ADR extracts on B16F10 cells were also evaluated. We found that the L. acidophilus-fermented ADR extract at 1.5 mg/mL showed significant cellular antityrosinase activity with low melanin production in B16F10 cells and was noncytotoxic to B16F10 cells. Among all probiotic bacteria, water-extracted ADR fermented by L. acidophilus for 48 h was found to be the best skincare agent or antioxidant agent.

Utility of Ochrobactrum anthropi YC152 in a Microbial Fuel Cell as an Early Warning Device for Hexavalent Chromium Determination.

Fast hexavalent chromium (Cr(VI)) determination is important for environmental risk and health-related considerations. We used a microbial fuel cell-based biosensor inoculated with a facultatively anaerobic, Cr(VI)-reducing, and exoelectrogenic Ochrobactrum anthropi YC152 to determine the Cr(VI) concentration in water. The results indicated that O. anthropi YC152 exhibited high adaptability to pH, temperature, salinity, and water quality under anaerobic conditions. The stable performance of the microbial fuel cell (MFC)-based biosensor indicated its potential as a reliable biosensor system. The MFC voltage decreased as the Cr(VI) concentration in the MFC increased. Two satisfactory linear relationships were observed between the Cr(VI) concentration and voltage output for various Cr(VI) concentration ranges (0.0125-0.3 mg/L and 0.3-5 mg/L). The MFC biosensor is a simple device that can accurately measure Cr(VI) concentrations in drinking water, groundwater, and electroplating wastewater in 45 min with low deviations (<10%). The use of the biosensor can help in preventing the violation of effluent regulations and the maximum allowable concentration of Cr(VI) in water. Thus, the developed MFC biosensor has potential as an early warning detection device for Cr(VI) determination even if O. anthropi YC152 is a possible opportunistic pathogen.

(4R,6S)-2-Dihydromenisdaurilide is a Butenolide that Efficiently Inhibits Hepatitis C Virus Entry.

Without a vaccine, hepatitis C virus (HCV) remains a significant threat, putting 170-300 million carriers worldwide at risk of cirrhosis and hepatocellular carcinoma. Although the direct-acting antivirals targeting HCV replication have revolutionized the treatment of hepatitis C, several obstacles persist, including resistance development, potential side-effects, and the prohibitive cost that limits their availability. Furthermore, treatment of HCV re-infection in liver transplantation remains a significant challenge. Developing novel antivirals that target viral entry could help expand the scope of HCV therapeutics and treatment strategies. Herein, we report (4R,6S)-2-dihydromenisdaurilide (DHMD), a natural butenolide, as an efficient inhibitor of HCV entry. Specifically, DHMD potently inhibited HCV infection at non-cytotoxic concentration. Examination on the viral life cycle demonstrated that DHMD selectively targeted the early steps of infection while leaving viral replication/translation and assembly/release unaffected. Furthermore, DHMD did not induce an antiviral interferon response. Mechanistic dissection of HCV entry revealed that DHMD could inactivate cell-free virus, abrogate viral attachment, and inhibit viral entry/fusion, with the most pronounced effect observed against the viral adsorption phase as validated using ELISA and confocal microscopy. Due to its potency, DHMD may be of value for further development as an entry inhibitor against HCV, particularly for application in transplant setting.

Activity-based and fraction-guided analysis of Phyllanthus urinaria identifies loliolide as a potent inhibitor of hepatitis C virus entry.

Without a vaccine, hepatitis C virus (HCV) remains a global medical and socio-economic burden, predisposing about 170 million carriers worldwide to end-stage liver diseases including cirrhosis and hepatocellular carcinoma. Although the recently developed direct-acting antivirals (DAAs) have revolutionized hepatitis C treatment, most of them are unsuitable for monotherapy due to risks of resistance, thus necessitating combination with interferon (IFN)-alpha, ribavirin, or additional DAAs. More importantly, the high cost associated with the DAAs restricts their accessibility to most parts of the world. Developing novel cost-effective anti-HCV therapeutics may help expand the scope of antivirals and treatment strategies against hepatitis C. Herein, we applied an activity-based and fraction-guided analysis of extracts from the medicinal plant Phyllanthus urinaria (P. urinaria), which yielded fraction 13 (F13) as possessing the most potent inhibitory activity against early viral entry of cell-culture HCV infection. Chemical analysis (silica gel chromatography followed by ESI LC-MS plus (1)H and (13)C NMR) of F13 identified loliolide (LOD), a monoterpenoid lactone, as a novel inhibitor of HCV entry. Specifically, LOD could efficiently inactivate HCV free virus particles, abrogate viral attachment, and impede viral entry/fusion, with minimal effect on viral replication/translation, particle production, and induction of type I IFN host antiviral immune response. ELISA-based binding analysis confirmed the monoterpenoid's ability in efficiently blocking HCV particle attachment to the host cell surface. Furthermore, LOD could inhibit infection by several genotypic strains of HCV. This is the first report characterizing P. urinaria and its bioactive compound LOD as potent HCV entry inhibitors, which merit further evaluation for development as candidate antiviral agents against hepatitis C.

Analysis of bacterial diversity and efficiency of continuous removal of Victoria Blue R from wastewater by using packed-bed bioreactor.

The characteristics of a packed-bed bioreactor (PBB) for continuously removing Victoria Blue R (VBR) from an aqueous solution were determined. The effects of various factors including liquid retention time (RT), VBR concentration, shock loading, and coexisting compounds on the VBR removal and bacterial community in a continuous system were investigated. The intermediates of degraded VBR and the acute toxicity of the effluent from PBB were analyzed. When the VBR concentration was lower than 400 mg/l for a two-day retention time (RT), 100% removal was achieved. During continuous operation, the efficiency initially varied with the VBR concentration and RT, but gradually increased in one to two days. Furthermore, the acute toxicity of the effluent reduced by a factor of 21.25-49.61, indicating that the PBB can be successfully operated under turbulent environmental conditions. VBR degradation involved stepwise demethylation and yielded partially dealkylated VBR species. Phylogenetic analysis showed that the dominant phylum in the PBB was Proteobacteria and that Aeromonas hydrophila dominated during the entire operating period. The characteristics of the identified species showed that the PBB is suitable for processes such as demethylation, aromatic ring opening, carbon oxidation, nitrification, and denitrification.

Antioxidant, anti-adipocyte differentiation, antitumor activity and anthelmintic activities against Anisakis simplex and Hymenolepis nana of yakuchinone A from Alpinia oxyphylla.

BACKGROUND: Alpinia oxyphylla is a common remedy in traditional Chinese medicine. Yakuchinone A is a major constituent of A. oxyphylla and exhibits anti-inflammatory, antitumor, antibacterial, and gastric protective activities. METHODS: Antioxidant and antitumor characteristics of yakuchinone A in skin cancer cells as well as novel mechanisms for the inhibition of adipocyte differentiation, cestocidal activities against Hymenolepis nana adults, and nematocidal activities against Anisakis simplex larvae are investigated. RESULTS: Yakuchinone A presents the ability of the removal of DPPH·and ABTS+ free radicals and inhibition of lipid peroxidation. Yakuchinone A suppresses intracellular lipid accumulation during adipocyte differentiation in 3 T3-L1 cells and the expressions of leptin and peroxisome proliferator-activated receptor γ (PPARγ). Yakuchinone A induces apoptosis and inhibits cell proliferation in skin cancer cells. The inhibition of cell growth by yakuchinone A is more significant for non-melanoma skin cancer (NMSC) cells than for melanoma (A375 and B16) and noncancerous (HaCaT and BNLCL2) cells. Treatment BCC cells with yakuchinone A shows down-regulation of Bcl-2, up-regulation of Bax, and an increase in cleavage poly (ADP-ribose) polymerase (PARP). This suggests that yakuchinone A induces BCC cells apoptosis through the Bcl-2-mediated signaling pathway. The anthelmintic activities of yakuchinone A for A. simplex are better than for H. nana. CONCLUSIONS: In this work, yakuchinone A exhibits antioxidative properties, anti-adipocyte differentiation, antitumor activity, and anthelmintic activities against A. simplex and H. nana.