In vitro genotoxic effects of ZnO nanomaterials in human peripheral lymphocytes

In this study, possible genotoxic effects of zinc oxide (ZnO) nanoparticles were investigated in cultured human peripheral lymphocytes by using chromosome aberrations and micronucleus assays (MN). For this purpose, the cells were treated with ZnO (1, 2, 5, 10, 15 and 20 μg/mL) for 24 and 48 h. In this research, four types of chromosome aberrations were observed as chromatid and chromosome breaks, fragment and dicentric chromosomes. ZnO induced significant increase of the ratio of chromosomal aberrations as well as percentage of abnormal cells at concentrations of 1, 5, 10 and 20 μg/mL in 24 h treatments. In 48 h treatments, while ZnO nanomaterials induced significant increase of the percentage of abnormal cells only at a concentration of 10 μg/mL, and of chromosome aberration per cell in comparison to the control at concentrations of 5 and 10 μg/mL. On the other hand, this material significantly increased the micronuclei frequency (MN) at concentrations of 10 and 15 μg/mL in comparison to the control. Cytokinesis-block proliferation index was not affected by ZnO treatments. It also decreased the mitotic index in all concentrations at 24 h but not at 48 h. The present results indicate that ZnO nanoparticles are clastogenic, mutagenic and cytotoxic to human lymphocytes in vitro at specific concentrations and time periods.     

Effects of a Standardized Phenolic-Enriched Maple Syrup Extract on β-Amyloid Aggregation,Neuroinflammation in Microglial and Neuronal Cells,and β-Amyloid Induced Neurotoxicity in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis>

Published data supports the neuroprotective effects of several phenolic-containing natural products, including certain fruit, berries, spices, nuts, green tea, and olive oil. However, limited data are available for phenolic-containing plant-derived natural sweeteners including maple syrup. Herein, we investigated the neuroprotective effects of a chemically standardized phenolic-enriched maple syrup extract (MSX) using a combination of biophysical, in vitro, and in vivo studies. Based on biophysical data (Thioflavin T assay, transmission electron microscopy, circular dichroism, dynamic light scattering, and zeta potential), MSX reduced amyloid β_1?42 peptide (Aβ_1?42) fibrillation in a concentration-dependent manner (50–500 μg/mL) with similar effects as the neuroprotective polyphenol, resveratrol, at its highest test concentration (63.5?% at 500 μg/mL vs. 77.3?% at 50 μg/mL, respectively). MSX (100 μg/mL) decreased H₂O₂-induced oxidative stress (16.1?% decrease in ROS levels compared to control), and down-regulated the production of lipopolysaccharide (LPS)-stimulated inflammatory markers (22.1, 19.9, 74.8, and 87.6?% decrease in NOS, IL-6, PGE₂, and TNFα levels, respectively, compared to control) in murine BV-2 microglial cells. Moreover, in a non-contact co-culture cell model, differentiated human SH-SY5Y neuronal cells were exposed to conditioned media from BV-2 cells treated with MSX (100 μg/mL) and LPS or LPS alone. MSX-BV-2 media increased SH-SY5Y cell viability by 13.8?% compared to media collected from LPS-BV-2 treated cells. Also, MSX (10 μg/mL) showed protective effects against Aβ_1?42 induced neurotoxicity and paralysis in Caenorhabditis elegans in vivo. These data support the potential neuroprotective effects of MSX warranting further studies on this natural product.     

Effect of N-salicyloyltryptamine (STP), a novel tryptamine analogue, on parameters of cell viability, oxidative stress, and immunomodulation in RAW 264.7 macrophages

Immunomodulatory actions exerted by some classes of tryptamines, such as benzoyltryptamine analogues, suggest these molecules as promising candidates to develop new therapies to treat conditions associated to acute and chronic pain and inflammation. N-salicyloyltryptamine (STP) was observed to act as an anticonvulsive agent and exert antinociceptive effects in mouse. In the present work, we performed a screening of cytotoxic, cytoprotective, immunomodulatory, and redox properties of STP in RAW 264.7 macrophages challenged with hydrogen peroxide and LPS. Our results show that STP presents no cytotoxicity in the range of 0.001 to 1 μg/mL, but doses of 50 and 100 μg/mL caused loss of cell viability (IC₅₀?=?22.75 μg/mL). Similarly, STP at 0.001 to 1 μg/mL did not cause oxidative stress to RAW 264.7 cells, although it did not prevent cell death induced by H₂O₂ 0.5 mM. At 1 μg/mL, STP reversed some redox and inflammatory parameters induced by LPS. These include thiol (sulfhydryl) oxidation, superoxide dismutase activation, and morphological changes associated to macrophage activation. Besides, STP significantly inhibited LPS-induced TNF-α and IL-1β release, as well as CD40 and TNF-α protein upregulation. Signaling events induced by LPS, such as phosphorylation of ERK 1/2 and IκBα and p65 nuclear translocation (NF-kB activation) were also inhibited by STP. These data indicate that STP is able to modulate inflammatory parameters at doses that do not interfere in cell viability.     

Evaluation of the DNA damaging effects of amitraz on human lymphocytes in the Comet assay

Amitraz is formamidine pesticide widely used as insecticide and acaricide. In veterinary medicine, amitraz has important uses against ticks, mites and lice on animals. Also, amitraz is used in apiculture to control Varroa destructor. It this study, the alkaline Comet assay was used to evaluate DNA damaging effects of amitraz in human lymphocytes. Isolated human lymphocytes were incubated with varying concentrations of amitraz (0.035, 0.35, 3.5, 35 and 350 μg/mL). The Comet assay demonstrated that all concentrations of amitraz caused statistically significant increase in the level of DNA damage, thus indicating that amitraz possesses genotoxic potential. The concentration of amitraz that produced the highest DNA damage (3.5 μg/mL) was chosen for further analysis with the antioxidant catalase. The obtained results showed that co-treatment with antioxidant catalase (100 IU/mL or 500 IU/mL) significantly reduced the level of DNA damage, indicating the possible involvement of reactive oxygen species in DNA damaging effects of amitraz. Flow cytometric analysis revealed increase of the apoptotic index following treatment with amitraz. However, co-treatment with catalase reduced the apoptotic index, while treatment with catalase alone reduced the percentage of apoptotoc cells even in comparison with the negative control. Therefore, catalase had protective effects against ROS-mediated DNA damage and apoptosis.     

Bauhinia forficata Prevents Vacuous Chewing Movements Induced by Haloperidol in Rats and Has Antioxidant Potential In Vitro

Classical antipsychotics can produce motor disturbances like tardive dyskinesia in humans and orofacial dyskinesia in rodents. These motor side effects have been associated with oxidative stress production in specific brain areas. Thus, some studies have proposed the use of natural compounds with antioxidant properties against involuntary movements induced by antipsychotics. Here, we examined the possible antioxidant activity of Bauhinia forficata (B. forficata), a plant used in folk medicine as a hypoglycemic, on brain lipid peroxidation induced by different pro-oxidants. B. forficata prevented the formation of lipid peroxidation induced by both pro-oxidants tested. However, it was effective against lipid peroxidation induced by sodium nitroprusside (IC₅₀ = 12.08 μg/mL) and Fe²⁺/EDTA (IC₅₀ = 41.19 μg/mL). Moreover, the effects of B. forficata were analyzed on an animal model of orofacial dyskinesia induced by long-term treatment with haloperidol, where rats received haloperidol each 28 days (38 mg/kg) and/or B. forficata decoction daily (2.5 g/L) for 16 weeks. Vacuous chewing movements (VCMs), locomotor and exploratory activities were evaluated. Haloperidol treatment induced VCMs, and co-treatment with B. forficata partially prevented this effect. Haloperidol reduced the locomotor and exploratory activities of animals in the open field test, which was not modified by B. forficata treatment. Our present data showed that B. forficata has antioxidant potential and partially protects against VCMs induced by haloperidol in rats. Taken together, our data suggest the protection by natural compounds against VCMs induced by haloperidol in rats.     

Non-toxic plant metabolites regulate Staphylococcus viability and biofilm formation: a natural therapeutic strategy useful in the treatment and prevention of skin infections

In the present study, the efficacy of generally recognised as safe (GRAS) antimicrobial plant metabolites in regulating the growth of Staphylococcus aureus and S. epidermidis was investigated. Thymol, carvacrol and eugenol showed the strongest antibacterial action against these microorganisms, at a subinhibitory concentration (SIC) of ≤ 50 μg ml^?1. Genistein, hydroquinone and resveratrol showed antimicrobial effects but with a wide concentration range (SIC = 50–1,000 μg ml^?1), while catechin, gallic acid, protocatechuic acid, p-hydroxybenzoic acid and cranberry extract were the most biologically compatible molecules (SIC ≥ 1000 μg ml^?1). Genistein, protocatechuic acid, cranberry extract, p-hydroxybenzoic acid and resveratrol also showed anti-biofilm activity against S. aureus, but not against S. epidermidis in which, surprisingly, these metabolites stimulated biofilm formation (between 35% and 1,200%). Binary combinations of cranberry extract and resveratrol with genistein, protocatechuic or p-hydroxibenzoic acid enhanced the stimulatory effect on S. epidermidis biofilm formation and maintained or even increased S. aureus anti-biofilm activity.     

Zingerone Protects Against Stannous Chloride-Induced and Hydrogen Peroxide-Induced Oxidative DNA Damage In Vitro

In this paper, we report the dose-dependent antioxidant activity and DNA protective effects of zingerone. At 500 μg/mL, the DPPH radical scavenging activity of zingerone and ascorbic acid as a standard was found to be 86.7 and 94.2 % respectively. At the same concentration, zingerone also showed significant reducing power (absorbance 0.471) compared to that of ascorbic acid (absorbance 0.394). The in vitro toxicity of stannous chloride (SnCl₂) was evaluated using genomic and plasmid DNA. SnCl₂-induced degradation of genomic DNA was found to occur at a concentration of 0.8 mM onwards with complete degradation at 1.02 mM and above. In the case of plasmid DNA, conversion of supercoiled DNA into the open circular form indicative of DNA nicking activity was observed at a concentration of 0.2 mM onwards; complete conversion was observed at a concentration of 1.02 mM and above. Zingerone was found to confer protection against SnCl₂-induced oxidative damage to genomic and plasmid DNA at concentrations of 500 and 750 μg/mL onwards, respectively. This protective effect was further confirmed in the presence of UV/H₂O₂-a known reactive oxygen species (ROS) generating system-wherein protection by zingerone against ROS-mediated DNA damage was observed at a concentration of 250 μg/mL onwards in a dose-dependent manner. This study clearly indicated the in vitro DNA protective property of zingerone against SnCl₂-induced, ROS-mediated DNA damage.     

Nisin Adsorption in Colloidal Systems Formed with Phytoglycogen Octenyl Succinate

While antimicrobial compounds are often used against food pathogens, they are liable to quick degradations in foods. One way to achieve their sustained efficacy is through the use of protective delivery systems. The overall goal of this study was to understand the interactions between nisin, an antimicrobial peptide, and phytoglycogen octenyl succinate (PG-OS), a dendrimer-like amphiphilic carbohydrate polymer in aqueous (non-emulsion) and emulsion based colloidal systems. Nisin interacts with PG-OS particulates following a Langmuir monolayer adsorption pattern in both systems. The monolayer adsorption capacity (Q_m) ranged from 37.6 to 106.4 μg/mL in non-emulsion, and was 181.8 μg/mL in PG-OS stabilized emulsion. At the same doses of PG-OS (5.0 mg/mL) and nisin (200 μg/mL), the concentration of adsorbed nisin in emulsion and non-emulsion were 157 and 22 μg/mL, respectively. This study showed that both the chemical nature and physical distribution of PG-OS particulates would affect nisin adsorption, which may provide a method for designing carbohydrate colloidal systems to achieve effective protection of antimicrobial compounds for foods.     

Substrates and enzyme activities related to biotransformation of resveratrol from phenylalanine by Alternaria sp. MG1

To identify the substrates and enzymes related to resveratrol biosynthesis in Alternaria sp. MG1, different substrates were used to produce resveratrol, and their influence on resveratrol production was analyzed using high performance liquid chromatography (HPLC). Formation of resveratrol and related intermediates was identified using mass spectrum. During the biotransformation, activities of related enzymes, including phenylalanine ammonia-lyase (PAL), trans-cinnamate 4-hydroxylase (C4H), and 4-coumarate-CoA ligase (4CL), were analyzed and tracked. The reaction system contained 100 mL 0.2 mol/L phosphate buffer (pH 6.5), 120 g/L Alternaria sp. MG1 cells, 0.1 g/L MgSO₄, and 0.2 g/L CaSO₄ and different substrates according to the experimental design. The biotransformation was carried out for 21 h at 28 °C and 120 rpm. Resveratrol formation was identified when phenylalanine, tyrosine, cinnamic acid, and p-coumaric acid were separately used as the only substrate. Accumulation of cinnamic acid, p-coumaric acid, and resveratrol and the activities of PAL, C4H, and 4CL were identified and changed in different trends during transformation with phenylalanine as the only substrate. The addition of carbohydrates and the increase of phenylalanine concentration promoted resveratrol production and yielded the highest value (4.57 μg/L) when 2 g/L glucose, 1 g/L cyclodextrin, and phenylalanine (4.7 mmol/L) were used simultaneously.     

Antigenotoxic effect of lipoic acid against mitomycin-C in human lymphocyte cultures

Antitumor agents are used in therapy against many forms of human cancer. One of these is mitomycin-C (MMC). As with many agents, it can interact with biological molecules and can induce genetic hazards in non-tumor cells. One of the possible approaches to protect DNA from this damage is to supply antioxidants that can remove free radicals produced by antitumor agents. Lipoic acid (LA) is known as one of the most powerful antioxidants. The aim of this study was to investigate antigenotoxic effects of LA against MMC induced chromosomal aberrations (CA), sister chromatid exchanges (SCE) and micronucleus (MN) formation in human lymphocytes. Lymphocytes were treated with 0.2 μg MMC/heparinized mL for 48 h. Three different concentrations (0.5, 1, 2 μg/mL) of LA were used together with MMC in three different applications; 1 h pre-treatment, simultaneous treatment and 1 h post-treatment. A negative, a positive and a solvent control were also included. In all the cultures treated with MMC + LA, the frequency of abnormal cells and CA/cell significantly decreased compared to MMC. Statistically significant reduction was also observed in SCE/cell and MN frequencies in all treatments. These results demonstrated anticlastogenic and antimutagenic effects of LA against MMC induced genotoxicity. LA showed the most efficient effect during 1 h pretreatment. On the other hand, MMC + LA treatments induced significant reduction in mitotic index than that of MMC treatment alone. These results are encouraging that LA can be a possible chemopreventive agent in tumorigenesis in both cancer patients and in health care persons handling anti-cancer drugs.     

Novel α,β-unsaturated amide derivatives bearing α-amino phosphonate moiety as potential antiviral agents

Based on flexible construction and broad bioactivity of ferulic acid, a series of novel α,β-unsaturated amide derivatives bearing α-aminophosphonate moiety were designed, synthesized and systematically evaluated for their antiviral activity. Bioassay results indicated that some compounds exhibited good antiviral activities against cucumber mosaic virus (CMV) and tobacco mosaic virus (TMV) in vivo. Especially, compound g18 showed excellent curative and protective activities against CMV, with half-maximal effective concentration (EC₅₀) values of 284.67 μg/mL and 216.30 μg/mL, which were obviously superior to that of Ningnanmycin (352.08 μg/mL and 262.53 μg/mL). Preliminary structure-activity relationships (SARs) analysis revealed that the introduction of electron-withdrawing group at the 2-position or 4-position of the aromatic ring is favorable for antiviral activity. Present work provides a promising template for development of potential inhibitor of plant virus.     

Design,synthesis and in vitro anti-mycobacterial evaluation of gatifloxacin-1H-1,2,3-triazole-isatin hybrids

A set of novel gatifloxacin-1H-1,2,3-triazole-isatin hybrids 6a-l was designed, synthesized and evaluated for their in vitro anti-mycobacterial activities against M. tuberculosis (MTB) H₃₇Rv and MDR-TB as well as cytotoxicity. The results showed that all the targets (MIC: 0.025–3.12 μg/mL) exhibited excellent inhibitory activity against MTB H₃₇Rv and MDR-TB, but were much more toxic (CC₅₀: 7.8–62.5 μg/mL) than the parent gatifloxacin (GTFX) (CC₅₀: 125 μg/mL). Among them, 61 (MIC: 0.025 μg/mL) was 2–32 times more potent in vitro than the references INH (MIC: 0.05 μg/mL), GTFX (MIC: 0.78 μg/mL) and RIF (MIC: 0.39 μg/mL) against MTB H₃₇Rv. The most active conjugate 6 k (MIC: 0.06 μg/mL) was 16–>2048 times more potent than the three references (MIC: 1.0–>128 μg/mL) against MDR-TB. Both of the two hybrids warrant further investigations.     

Swainsonine,a novel fungal metabolite: optimization of fermentative production and bioreactor operations using evolutionary programming

The optimization of bioreactor operations towards swainsonine production was performed using an artificial neural network coupled evolutionary program (EP)-based optimization algorithm fitted with experimental one-factor-at-a-time (OFAT) results. The effects of varying agitation (300–500 rpm) and aeration (0.5–2.0 vvm) rates for different incubation hours (72–108 h) were evaluated in bench top bioreactor. Prominent scale-up parameters, gassed power per unit volume (P _g/V _L, W/m³) and volumetric oxygen mass transfer coefficient (K _L a, s^?1) were correlated with optimized conditions. A maximum of 6.59 ± 0.10 μg/mL of swainsonine production was observed at 400 rpm-1.5 vvm at 84 h in OFAT experiments with corresponding P _g/V_L and K _L a values of 91.66 W/m³ and 341.48 × 10^?4 s^?1, respectively. The EP optimization algorithm predicted a maximum of 10.08 μg/mL of swainsonine at 325.47 rpm, 1.99 vvm and 80.75 h against the experimental production of 7.93 ± 0.52 μg/mL at constant K _L a (349.25 × 10^?4 s^?1) and significantly reduced P _g/V _L (33.33 W/m³) drawn by the impellers.     

Acaricidal activities of bicyclic monoterpene ketones from Artemisia iwayomogi against Dermatophagoides spp.

The acaricidal properties of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one isolated from Artemisia iwayomogi and its structural analogues were evaluated against Dermatophagoides farinae and D. pteronyssinus, and their effects were compared with that of the commercial acaricide benzyl benzoate. Based on the 50 % lethal dose (LD₅₀) values against D. farinae, 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (0.82 μg/cm²) was 9.71 times more effective than benzyl benzoate (7.96 μg/cm²), followed by (1R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (1.03 μg/cm²), (1S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (1.58 μg/cm²), and (1R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one oxime (3.05 μg/cm²) in a filter paper bioassay. The acaricidal activities of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one and its structural analogues against D. pteronyssinus were similar to those against D. farinae. These results demonstrate that naturally occurring A. iwayomogi-isolated 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one and its structural analogues are suitable for the production of natural acaricides against house dust mites.     

Lasalliapustulata lichen as possible natural antigenotoxic,antioxidant, antimicrobial and anticancer agent

The methanol extract of the lichen Lasallia pustulata was tested for genotoxic, antioxidant, antimicrobial and anticancer activities. We did this using a cytokinesis block micronucleus (MN) assay on peripheral blood lymphocytes, by measuring free radical and superoxide anion scavenging activity, reducing power, determining of total phenolic compounds and determining the total flavonoid content, measuring the minimal inhibitory concentration by the broth microdilution method against five species of bacteria and five species of fungi and by using the microculture tetrazolium test on FemX (human melanoma) and LS174 (human colon carcinoma) cell lines. As a result of this study, we found that the methanol extract of L. pustulata did not modify the frequency of the MN and nuclear division index in comparison to untreated cells (p > 0.05). These results revealed that the methanol extract had moderate free radical scavenging activity with IC₅₀ values of 395.56 μg/mL. Moreover, the extract tested had effective reducing power and superoxide anion radical scavenging. The values of the minimum inhibitory concentration against the tested microorganisms ranged from 0.625 to 20 mg/mL. In addition, the extract tested had strong anticancer activity against both cell lines with IC₅₀ values of 46.67 and 71.71 μg/mL.     

Concentrations and Health Risk of Polycyclic Aromatic Hydrocarbons in Some Brands of Biscuits in the Nigerian Market

Concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in 40 brands of biscuits in the Nigerian market. The analyses were performed by gas chromatography-flame ionisation detection (GC-FID) after Soxhlet extraction of the sample with hexane/dichloromethane and clean-up of the extract. The concentrations of Σ16 PAHs in these biscuit samples were in the range of 35.7–645.3 μg kg^?1, 75.9–490.7 μg kg^?1, 91.5–537 μg kg^?1, 18.4–522.2 μg kg^?1, 123.5–393.8 μg kg^?1, 167.2–880 μg kg^?1, 136.5–316 μg kg^?1, and 135.5–241.6 μg kg^?1 for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The concentrations of Σ8 carcinogenic PAHs in the samples ranged from not detected (nd)–323.3 μg kg^?1, 15.7–138 μg kg^?1, 9.7–312.9 μg kg^?1, nd–331.7 μg kg^?1, nd–220.9 μg kg^?1, nd–53.3 μg kg^?1, 18.4–56.6 μg kg^?1, and 6.6–170.8 μg kg^?1 for shortcake, digestives, cookies, shortbread, wafers, crackers, Pringles, and cabin, respectively. The margin of exposure (MOE), based on PAH8 as an indicator for the occurrence and effects of PAHs in food, was less than 10,000, the serious health effects value, in 30% and 8% of the brands for the child and adult scenarios, respectively.     

The Usefulness of Non-Toxic Plant Metabolites in the Control of Bacterial Proliferation

The effect of generally recognised as safe (GRAS) plant metabolites in regulating the growth of human pathogenic and probiotic bacteria and in the formation of biofilm was investigated. Thymol, carvacrol and eugenol showed the strongest antibacterial action against both pathogenic and probiotic microorganisms, at a subinhibitory concentration (SIC) of ≤50 μg ml^?1. Genistein, hydroquinone, p-hydroxybenzoic acid and resveratrol also showed antibacterial effects but at a wide concentration range (SIC = 50–1000 μg ml^?1). Catechin, gallic acid, protocatechuic acid and cranberry extracts were the most biologically compatible molecules (SIC ≥ 1000 μg ml^?1). Regarding the effect on biofilm, it was observed that thymol, carvacrol and eugenol showed antibiofilm activity against all potential pathogenic bacteria tested whilst specifically enhancing probiotic aggregation. Catechin, genistein and cranberry extracts did not inhibit the pathogenic aggregation but they stimulated probiotic biofilm formation, whilst gallic acid, protocateuchic acid, hydroquinone, p-hydroxybenzoic acid and resveratrol did not show opposite effect on biofilm formation between pathogenic and probiotic microorganisms. These results indicate that an appropriate combination of GRAS plant metabolites, which have traditionally been used as dietary constituents due to their health-promoting characteristics, can also be extremely useful in the regulation of bacterial proliferation in the intestinal microbiota. Hence, it is suggested to apply these natural GRAS molecules as dietary supplements in the food industry in order to promote probiotic viability and to prevent or reduce colonisation or proliferation of intestinal pathogens.     

Effects of different omega-3 sources,fish oil,krill oil,and green-lipped mussel against cytokine-mediated canine cartilage degradation

Our purpose was to evaluate the protective effect of three marine omega-3 sources, fish oil (FO), krill oil (KO), and green-lipped mussel (GLM) against cartilage degradation. Canine cartilage explants were stimulated with either 10 ng/mL interleukin-1β (IL-1β) or IL-1β/oncostatin M (10 ng/mL each) and then treated with various concentrations of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA; 3 and 30 μg/mL), FO, KO, or GLM (250, 500, and 1000 μg/mL) for 28 days. Gene expression was then investigated in primary canine chondrocytes. Our results showed that DHA and EPA as well as omega-3 sources could suppress matrix degradation in cytokine-induced cartilage explants by significantly reducing the increase of sulfated glycosaminoglycans (s-GAGs) and preserving uronic acid and hydroxyproline content (except GLM). These agents were not able to reduce IL-1β-induced IL1B and TNFA expression but were able to down-regulate the expression of the catabolic genes MMP1, MMP3, and MMP13 and up-regulate the anabolic genes AGG and COL2A1; FO and KO were especially effective. Our findings indicated that FO and KO were superior to GLM for their protective effect against proteoglycan and collagen degradation. Hence, FO and KO could serve as promising sources of chondroprotective agents.     

Formation,regeneration, and transformation of protoplasts of Streptomyces diastatochromogenes 1628

Toyocamycin exhibits effective biological activities for use against plant pathogenic fungi thanks to its structural similarity to nucleoside. It has been recognized as a promising agricultural antibiotic utilized in controlling the occurrence of plant diseases. In our previous study, a strain that was isolated was identified and designated as Streptomyces diastatochromogenes whose major secondary metabolite was toyocamycin, but the production was largely limited. Protoplast transformation is a useful technique in the improvement of streptomycete. In this study, we optimized some key factors necessary for protoplast formation, regeneration, and transformation of S. diastatochromogenes. When mycelium was cultivated in CP medium with 1 % glycine, harvested at 48 h old, and then treated with 3 mg lysozyme/mL in P buffer for 1 h, the greatest regeneration frequency (42.5 %) of protoplasts was obtained. By using 1?×?10⁹/mL protoplasts with polyethylene glycol 1000 at a concentration of 30 % (w/v), the best performance of protoplast transformation efficiency was 4.8?×?10³/μg DNA transformants.     

Design,synthesis and biological activity evaluation of novel 2,6-difluorobenzamide derivatives through FtsZ inhibition

Novel series of 3-substituted 2,6-difluorobenzamide derivatives as FtsZ inhibitors were designed, synthesized and evaluated for their in vitro antibacterial activity against various phenotype of Gram-positive and Gram-negative bacteria, and their cell division inhibitory activity against three representative strains. As a result, 3-chloroalkoxy derivative 7, 3-bromoalkoxy derivative 12 and 3-alkyloxy derivative 17 were found to exhibit the best antibacterial activity against Bacillus subtilis with MICs of 0.25–1 μg/mL, and good activity (MIC < 10 μg/mL) against both susceptible and resistant Staphylococcus aureus. Additionally, all the three compounds displayed potent cell division inhibitory activity with MIC values of below 1 μg/mL against Bacillus subtilis and Staphylococcus aureus.