Effect of dietary α-ketoglutarate and allicin supplementation on the composition and diversity of the cecal microbial community in growing pigs.

BACKGROUND: The search for substitutes for antibiotics has recently become urgent. In our previous work, dietary α-ketoglutarate (AKG) combined with allicin improved growth performance and enhanced immunity in growing pigs, whereas the effects on them of intestinal microbiota were unclear. Here, we further investigate the effects of dietary AKG and allicin supplementation on the composition and diversity of intestinal microbiota in growing pigs. RESULTS: Treatment with a combination of AKG and allicin enhanced cecal bacteria richness and diversity, as evidenced by changes in Chao 1, ACE, Shannon, and Simpson values when compared to the control group and antibiotics group. At the phylum level, Bacteroidetes and Firmicutes were the two most abundant phyla. Treatment with a combination of AKG and allicin increased the numbers of Firmicutes and reduced the numbers of Bacteroidetes. Prevotella was the most abundant genus; it was increased by treatment with a combination of AKG and allicin. Furthermore, compared with the antibiotic group, the level of acetate was increased in the AKG group with or without allicin. Treatment with a combination of AKG and allicin increased the levels of cecal butyrate and total volatile fatty acids (VFA) when compared with the control group in growing pigs. CONCLUSION: Dietary 1.0% AKG combined with 0.5% allicin improved cecal microbial composition and diversity, which might further promote VFA metabolism in growing pigs. © 2018 Society of Chemical Industry.

L-Glutamine and L-arginine protect against enterotoxigenic Escherichia coli infection via intestinal innate immunity in mice.

Dietary glutamine (Gln) or arginine (Arg) supplementation is beneficial for intestinal health; however, whether Gln or Arg may confer protection against Enterotoxigenic Escherichia coli (ETEC) infection is not known. To address this, we used an ETEC-infected murine model to investigate the protective effects of Gln and Arg. Experimentally, we pre-treated mice with designed diet of Gln or Arg supplementation prior to the oral ETEC infection and then assessed mouse mortality and intestinal bacterial burden. We also determined the markers of intestinal innate immunity in treated mice, including secretory IgA response (SIgA), mucins from goblet cells, as well as antimicrobial peptides from Paneth cells. ETEC colonized in mouse small intestine, including duodenum, jejunum, and ileum, and inhibited the mRNA expression of intestinal immune factors, such as polymeric immunoglobulin receptor (pIgR), cryptdin-related sequence 1C (CRS1C), and Reg3γ. We found that dietary Gln or Arg supplementation decreased bacterial colonization and promoted the activation of innate immunity (e.g., the mRNA expression of pIgR, CRS1C, and Reg3γ) in the intestine of ETEC-infected mice. Our results suggest that dietary arginine or glutamine supplementation may inhibit intestinal ETEC infection through intestinal innate immunity.

A review of the immunomodulatory role of dietary tryptophan in livestock and poultry.

Tryptophan, a nutritionally essential amino acid, is active in the regulation of immune responses in animals. The products of tryptophan metabolism, such as indoleamine 2,3-dioxygenase, kynurenine, quinolinic acid, and melatonin, may improve immunity in an organism and induce anti-inflammatory responses. The immune tolerance processes mediated by tryptophan metabolites are not well understood. Recent studies have reported that the enzymes that break down tryptophan through the kynurenine metabolic pathway are found in numerous cell types, including immunocytes. Moreover, some tryptophan metabolites have been shown to play a role in the inhibition of T lymphocyte proliferation, elevation of immunoglobulin levels in the blood, and promotion of antigen-presenting organization in tissues. This review summarizes the effects and mechanisms of tryptophan and metabolites in immune functions in livestock and poultry. It also highlights the areas in which our understanding of the role(s) of tryptophan is incomplete and suggests possible future research that might prove of benefit to livestock and poultry producers.

Paenibacillus polysaccharolyticus sp. nov., a xylanolytic and cellulolytic bacteria isolated from leaves of Bamboo Phyllostachys aureosulcata.

A novel xylanolytic and cellulolytic strain, BL9T, was isolated from leaves of the Bamboo plants maintained at the Tamil Nadu Agricultural University Campus, Coimbatore, India. On the basis of the results of 16S rRNA gene analysis, it was determined to be phylogenetically close to the type strains of Paenibacillus amylolyticus NRRL NRS-290T (98.3 %), Paenibacillus barcinonensis BP-23T (98.1 %), Paenibacillus tundrae A10bT (98.0 %) and Paenibacillus xylanexedens B22aT (97.6 %). The strain stained Gram variable and was aerobic, motile and catalase- and oxidase-positive, with rod-shaped cells. Based upon the genome sequence, the average nucleotide identity with the related species ranged from 66 % to 72 %, and the digital DNA-DNA hybridization value ranged from 13 % to 27 %. The DNA G+C content was 45.6 mol%, meso-diaminopimelic acid was identified as the predominant component of the cell wall, and MK-7 was the only menaquinone in cell membranes. The whole-cell fatty acid profile included C16 : 0, iso-C14 : 0, anteiso-C15 : 0 and iso-C16 : 0. The polar lipids identified were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine and diphosphtidylglycerol. On the basis of these polyphasic taxonomic traits, BL9T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus polysaccharolyticus sp. nov. is proposed. The type strain is BL9T (=NBRC 105191T=ICMP 17623T).

Pseudomonas sesami sp. nov., a plant growth-promoting Gammaproteobacteria isolated from the rhizosphere of Sesamum indicum L.

A novel Gram-stain negative, aerobic, motile, rod-shaped bacterium was isolated from Sesame (Sesamum indicum L.) rhizosphere soil. Based on the 16S rRNA gene similarity value (99.4-98.6%) obtained with phylogenetically closely related strains and through analyses of their house keeping genes (atpD, infB and rpoB), the strain SI-P133T was delineated among the species of the genus Pseudomonas and was subjected to polyphasic taxonomic analysis. It was a chemoorganotroph which grew at wide range of temperature (4-45 °C), pH (5.5-9.5) and NaCl concentrations (0-7% (w/v). DNA-DNA hybridization values with closely related type strains DSM 9751T, DSM 19095T, DSM 21509T, ICMP 9151T and DSM 6929T ranged from 23.1 to 44.2%. The most abundant fatty acids were C16:0, C10:0 3-OH, summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c), C17:0 cyclo and C12:0 3-OH. The major isoprenoid quinone system was ubiquinone 9 (Q-9) and the G+C content was 61.3 mol%. The major polar lipids of the strain SI-P133T were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. With regard to prospective use in agriculture, plant growth-promoting properties of the strain were tested and plant growth-promotion was demonstrated under in vitro conditions. Based on the various polyphasic taxonomic traits analysed, the strain SI-P-133T was novel and placed within the genus Pseudomonas. Hence we propose a novel species named Pseudomonas sesami sp. nov., for which the type strain is SI-P133T (=NCIMB 14519T = KCTC 22518T).

Comparative analysis of mosquito (Diptera: Culicidae: Aedes aegypti Liston) responses to the insecticide Temephos and plant derived essential oil derived from Piper betle L.

Resistance to treatments with Temephos or plant derived oil, Pb-CVO, between a field collected Wild Strain (WS) and a susceptible Laboratory Strain (LS) of Ae. aegypti were measured. The Temephos (0.1mg/L) showed the greatest percentage of mosquito mortality compared to Pb-CVO (1.5mg/L) in LS Ae. aegypti. However, WS Ae. aegypti was not significantly affected by Temephos (0.1mg/L) treatment compare to the Pb-CVO (1.5mg/L). However, both strains (LS and WS) when treated with Pb-CVO (1.5mg/L) displayed steady larval mortality rate across all instars. The LC50 of Temephos was 0.027mg in LS, but increased in WS to 0.081mg/L. The LC50 of Pb-CVO treatment was observed at concentrations of 0.72 and 0.64mg/L for LS and WS strains respectively. The enzyme level of α- and ß-carboxylesterase was reduced significantly in both mosquito strains treated with Pb-CVO. Whereas, there was a prominent deviation in the enzyme ratio observed between LS and WS treated with Temephos. The GST and CYP450 levels were upregulated in the LS, but decreased in WS, after treatment with Temephos. However, treatment with Pb-CVO caused both enzyme levels to increase significantly in both the strains. Visual observations of the midgut revealed cytotoxicity from sub-lethal concentrations of Temephos (0.04mg/L) and Pb-CVO (1.0mg/L) in both strains of Ae. aegypti compared to the control. The damage caused by Temephos was slightly less in WS compared to LS mosquito strains.

Protective effects of Ficus carica leaves on glucose and lipids levels, carbohydrate metabolism enzymes and ß-cells in type 2 diabetic rats.

CONTEXT: The decoctions of Ficus carica Linn. (Moraceae) leaves are used in the folklore treatment of diabetes. OBJECTIVE: To evaluate the effect of F. carica on glucose and lipids levels, carbohydrate metabolism enzymes and ß-cells protective effects in type 2 diabetes. MATERIAL AND METHODS: Diabetes was induced in 15 days high-fat diet (HFD)-fed Wistar rats by intraperitoneal injection of streptozotocin (STZ) (40 mg/kg). The ethyl acetate extract (250 and 500 mg/kg) of F. carica leaves was administered for 28 days. Oral glucose tolerance (OGTT) and intraperitoneal insulin tolerance tests (ITT) were evaluated on 15th and 25th days, respectively. RESULTS: The ethyl acetate extract (250 and 500 mg/kg) of n F. carica leaves showed significant effect (p < 0.005) in the levels of blood glucose, total cholesterol (TC), triglycerides (TG), body weight and hepatic glycogen. In OGTT, F. carica (250 and 500 mg/kg) significantly (p < 0.005) detained the increase in blood glucose levels at 60 and 120 min and in ITT, F. carica enhanced the glucose utilization significantly (p < 0.005) over 30 and 60 min compared to diabetic control. Further, the altered activities of key carbohydrate metabolizing enzymes such as glucose-6-phosphatase, fructose-1,6-bisphosphatase and hexokinase in the liver tissue of diabetic rats were significantly (p < 0.005) reverted to near normal levels upon treatment with F. carica. Immumohistochemical studies of islets substantiated the cytoprotective effect on pancreatic ß-cells. DISCUSSION AND CONCLUSIONS: F. carica leaves exerted significant effect on carbohydrate metabolism enzymes with promising hypoglycemic and hypolipidemic activities in type 2 diabetic rats.

Paenibacillus methanolicus sp. nov., a xylanolytic, methanol-utilizing bacterium isolated from the phyllosphere of bamboo (Pseudosasa japonica).

Strain BL24T, isolated from bamboo phyllosphere collected in Coimbatore, India, was studied for taxonomic classification. Cells of the strain were aerobic, Gram-stain-positive, motile, catalase- and oxidase-positive rods and grew on media containing methanol. In 16S rRNA gene sequence analysis, strain BL24Tshowed the highest sequence similarities with Paenibacillus phyllosphaeraeKACC 11473T (97.8 %) and Paenibacillus sacheonensisSY01 (95.1 %). DNA-DNA hybridization with P. phyllosphaerae KACC 11473T, phylogenetically the most closely related species, was 21.6 %; this value showed that strain BL24Tbelonged to a different species. The cell-wall peptidoglycan was found to possess meso-diaminopimelic acid and the G+C content of genomic DNA was 52.1 mol %. It contained menaquinone (MK)-7 as the predominant respiratory quinone and the major cellular fatty acids are C16 : 0, anteiso-C15 : 0, iso-C16 : 0, and anteiso-C17 : 0. Based on the molecular and chemotaxonomic markers and physiological properties, strain BL24T (=NRRL B-51698T=CCM 7577T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillusmethanolicusis proposed.

Streptomyces pini sp. nov., an actinomycete isolated from phylloplane of pine (Pinus sylvestris L.) needle-like leaves.

A novel siderophore-producing actinomycete, designated PL19T, was isolated from the Scots-pine needle-like leaves collected from TNAU campus, Coimbatore, India. The isolate was chemoorganotrophic in nutrition and able to grow at 30 °C, and the optimum pH and NaCl facilitated the growth pH 6-11 and 0-8 % (w/v), respectively. The cells are filamentous and the mycelia formed are basically of wide and intricately branched substrate mycelium from which aerial mycelia arises, later gets differentiated into spores that are warty and arranged spirally. The 16S rRNA gene of strain PL19T was sequenced and was highly similar to the type strains of species of the genus Streptomyces, including Streptomyces barkulensis RC1831T (98.8 % pairwise similarity), Streptomyces fenghuangensis GIMN4.003T (98.2 %), Streptomyces nanhaiensis SCSIO 01248T (98.0 %), Streptomyces radiopugnans R97T (97.9 %), Streptomyces atacamensis C60T (97.8 %) and Streptomyces macrosporus NBRC 14749T (97.2 %), all of which were subjected to taxonomical characterization using a polyphasic approach. The strains showed unique carbon utilization patterns, and it possesses iso-C16 : 0 anteiso-C15 : 0 and anteiso-C17 : 0 as a major cellular fatty acids. The cell-wall was dominated with ll-type diaminopimelic acid, and the menaquinone type was MK-9(H6, H8). These chemotaxonomic evidences placed strain PL19T within the genus Streptomyces. The determination of G+C ratio (69.5 mol%) and DNA-DNA hybridization values (13.4-31.8 % with the phylogenetically related species) helped in further hierarchical classification of strain PL19T. Based on morphological, physiological and chemotaxonomic data as well as DNA-DNA hybridization values, strain PL19T could be distinguished from the evolutionarily closest species currently available. All these collective data show that strain PL19T represents a novel species of the genus Streptomyces, for which the name Streptomyces pini sp. nov. is proposed. The type strain is PL19T (=NRRL B-24728T=ICMP 17783T).

Isolation, identification and screening of antimicrobial thermophilic Streptomyces sp. Al-Dhabi-1 isolated from Tharban hot spring, Saudi Arabia.

The strain Streptomyces sp. Al-Dhabi-1 was isolated from soil sediments collected from Tharban hot spring in the southern west of Saudi Arabia using actinomycetes isolation agar and starch casein agar at 55 °C. Identification of the isolate was done according to morphological, physiological and biochemical characteristics and 16S rRNA sequence similarity as well. 16S rRNA sequence and blast analyses confirmed that the isolate belonging to the genus Streptomyces. The sequence was submitted to GenBank with accession number (KF815080). Ethyl acetate extract of Streptomyces sp. Al-Dhabi-1 showed good antimicrobial activities against tested pathogenic microbes. Minimum inhibitory concentration results showed that the best values were observed against S. agalactiae (<0.039 mg/ml) and Klebsiella pneumonia (0.125 mg/ml). Minimum inhibitory concentration of Al-Dhabi-1 against fungi; Cryptococcus neoformans (0.078 mg/ml), C. albicans (0.156 mg/ml), A. niger (0.625 mg/ml), and T. mentagrophytes (0.156 mg/ml). GC-MS analysis was used for the chemical profile of ethyl acetate extract. Benzeneacetic acid (16.02 %) and acetic acid 2-phenylethyl ester (10.35 %) were the major compounds among 31 substances found the ethyl acetate extract. According to the results of antimicrobial activity against pathogenic microbes, it is clear that the actinomycetes from hot springs with extreme environments are promising source for antimicrobial compounds.

Chitosan Modulates Inflammatory Responses in Rats Infected with Enterotoxigenic Escherichia coli.

This study aims to investigate the effects of dietary chitosan (COS) on gastrointestinal pathogen resistance in mice model. For two weeks, a control group of ICR mice received a basal diet whilst the intervention group received the basal diet supplemented with 300 mg/kg COS. After two weeks, the mice fed the supplemented diet had a lower body weight. Then enterotoxigenic Escherichia coli (E. coli) was administered to the mice through oral gavage, with each mouse receiving 108 CFU. At day 7 after infection, the bacterial load in the jejunum and faeces was significantly lower in the COS group than that in the control group. Moreover, the mRNA and protein levels of IL-1ß, IL-6, IL-17, IL-18, and TNF-α were significantly lower in the group of mice receiving the COS diet; also the jejunal production of toll-like receptor-4 (TLR-4) was suppressed in the COS group. These results indicate the intervention influenced inflammation and controlled E. coli infection.

Dietary Chitosan Supplementation Increases Microbial Diversity and Attenuates the Severity of Citrobacter rodentium Infection in Mice.

C57BL/6 mice were tested in order to investigate the effects of dietary chitosan (COS) supplements on intestinal microflora and resistance to Citrobacter rodentium infection. The findings reveal that, after consuming a 300 mg/kg COS diet for 14 days, microflora became more diverse as a result of the supplement. Mice receiving COS exhibited an increase in the percentage of Bacteroidetes phylum and a decrease in the percentage of Firmicutes phylum. After Citrobacter rodentium infection, the histopathology scores indicated that COS feeding resulted in less severe colitis. IL-6 and TNF-α were significantly lower in colon from COS-feeding mice than those in the control group. Furthermore, mice in COS group were also found to experience inhibited activation of nuclear factor-kappa B (NF-κB) in the colonic tissue. Overall, the findings revealed that adding 300 mg/kg COS to the diet changed the composition of the intestinal microflora of mice, resulting in suppressed NF-κB activation and less production of TNF-α and IL-6; and these changes led to better control of inflammation and resolution of infection with C. rodentium.

Target and non-target toxicity of botanical insecticide derived from Couroupita guianensis L. flower against generalist herbivore, Spodoptera litura Fab. and an earthworm, Eisenia foetida Savigny.

Botanical insecticides may provide alternatives to synthetic insecticides for controlling Spodoptera litura (F.) and they are target specific, biodegradable, and harmless to mammals. Eight natural chemical compounds with larvicidal activity were identified from fraction F6 of C. guianensis flower extract. Probit analysis of 95% confidence level exposed an LC50 of 223ppm against S. litura third instar larvae. The growth and development of S. litura was affected in sub-lethal concentrations of fraction F6 (50, 100, 150 and 200ppm) compared to controls. Similarly nutritional indices values decreased significantly compared to controls. Fraction F6 also damaged the gut epithelial layer and brush border membrane (BBM). This study also resolved the effects of toxicity to non-target earthworm treated with fraction F6 and chemical pesticides (monotrophos and cypermethrin) and the results showed that fraction F6 had no harmful effect on E. fetida. Further, fraction F6 was eluted and sub fractions F6c (50ppm) showed high mortality against S. litura third instar larvae. Octacosane from fraction F6c was established and confirmed using IR spectrum and HPLC. The time of retention of fraction F6c was confirmed with the octacosane standard. Fraction F6 of C. guianensis extract caused dose-dependent mortality towards S. litura. Octacosane in fraction F6c was establish to be the prominent chemical compound associated with causing mortality but other compounds present in the fraction F6 were shown to be associated with changes in development of S. litura at low dosages. S. litura at low dosage. Therefore, these findings suggest that octacosane may be one of the major insecticidal compounds affecting S. litura survival.

Potential mode of action of a novel plumbagin as a mosquito repellent against the malarial vector Anopheles stephensi, (Culicidae: Diptera).

Plumbagin was isolated and characterized from the roots of Plumbago zeylanica using chromatography: TLC, Column chromatogram, HPLC, FTIR and 1H NMR. The isolated pure compounds were assayed for potency as inhibitors of: acetylcholine esterase (AchE), glutathione S-transferases (GST), superoxide dismutase (SOD), cytochrome P450 and α, ß-esterase, and for repellency with Anopheles stephensi at four different concentrations (25, 50, 75 and 100ppm). The enzyme assay against the pure compound reveals that the level of esterase and SOD was decreased significantly in contrast the level of GST and cytochrome P450 was increased significantly. Our results suggests that novel Plumbagin has significantly alters the level of enzyme comparable to the control. Evaluations resulted in Plumbagin producing maximum repellency scores against An. stephensi mosquitoes in dose dependent manner with highest repellence was observed in the 100ppm. Histological examination showed that the midgut, hindgut and muscles are the most affected tissues. These tissues affected with major changes including separation and collapse of epithelial layer and cellular vacuolization. The results support the utility of plant compound Plumbagin for vector control as an alternative to synthetic insecticides, however, more vigorous field trials are needed to determine viability under natural conditions.

In vitro antimicrobial, antioxidant and cytotoxic properties of Streptomyces lavendulae strain SCA5.

BACKGROUND: Actinomycetes are Gram-positive, often filamentous, bacteria known for their unsurpassed capacity for the production of secondary metabolites with diverse biological activities. The aim of the present study was to evaluate the antimicrobial, cytotoxic and antioxidant properties of Streptomyces lavendulae strain SCA5. RESULTS: The ethyl acetate extract of SCA5 broth (EA-SCA5) showed antimicrobial activity with MIC value of 31.25 µg/ml. EA-SCA5 showed good antioxidant potential by scavenging 2, 2-diphenyl-picrylhydrazyl (DPPH) (IC50 507.61 ± 0.66 µg/ml), hydroxyl radical (IC50 617.84 ± 0.57 µg/ml), nitric oxide (IC50 730.92 ± 0.81 µg/ml) and superoxide anion radical (IC50 864.71 ± 1.15 µg/ml). The EA-SCA5 also showed strong suppressive effect on rat liver lipid peroxidation (IC50 838.83 ± 1.18 µg/ml). The total phenolic content of SCA5 was 577.12 mg of GAE equivalents/gram extract. EA-SCA5 exhibited cytotoxic activity on A549 adenocarcinoma lung cancer cell line. It showed 84.9% activity at 500 µg/ml with IC50 value of 200 µg/ml. The gas chromatography mass spectrometry (GC-MS) analysis revealed the presence of one major bioactive compound actinomycin C2. CONCLUSIONS: The results of this study indicate that the EA-SCA5 could be probed further for isolating some medically useful compounds.

In-vitro antimicrobial, antibiofilm, cytotoxic, antifeedant and larvicidal properties of novel quinone isolated from Aegle marmelos (Linn.) Correa.

BACKGROUND: Plant metabolites have wide applications and have the potential to cure different diseases caused by microorganisms. The aim of the study was to evaluate the antimicrobial, antibiofilm, cytotoxic, antifeedant and larvicidal properties of novel quinine isolated from Aegle marmelos (Linn.) Correa. METHODS: A compound was obtained by eluting the crude extract, using varying concentrations of the solvents by the chromatographic purification. Broth micro dilution method was used to assess the antimicrobial activity and anticancer study was evaluated using MTT assay. Larvicidal activity was studied using leaf disc no-choice method. RESULTS: Based on the IR, 13C NMR and 1H NMR spectral data, the compounds were identified as quinone related antibiotic. It exhibited significant activity against Gram positive and Gram negative bacteria. The lowest Minimum Inhibitory Concentration (MIC) of the compound against Bacillus subtilis and Staphylococcus aureus was 100 and 75 µg mL(-1) respectively. Against Escherichia coli and Pseudomonas aeruginosa it exhibited MIC value of 25 µg mL(-1). The MIC of the compound against Aspergillus niger, A. clavatus, Penicillium roqueforti was 20 µg mL(-1) and that against Fusarium oxysporum (20 µg mL(-1)), A. oryzae (40 µg mL(-1)), and Candida albicans (60 µg mL(-1)), respectively. It showed effective antibiofilm activity against E. coli, S. typhii and P. aeroginosa at 8 µg mL(-1) and did not exhibit considerable cytotoxic activity against Vero and HEP2 cell lines. Additionally, the compound documented significant antifeedant and larvicidal activities against Helicoverpa armigera and Spodoptera litura at 125, 250, 500 and 1000 ppm concentrations. CONCLUSION: The results concluded that the compound can be evaluated further in industrial applications and also an agent to prepare botanical new pesticide formulations.

Gastroprotective activity of violacein isolated from Chromobacterium violaceum on indomethacin-induced gastric lesions in rats: investigation of potential mechanisms of action.

Chromobacterium violaceum, Gram-negative bacteria species found in tropical regions of the world, produces a distinct deep violet-colored pigment called violacein. In the present study, we investigated whether violacein can promote a gastroprotective effect and verified the possible mechanisms involved in this action. For this study, an indomethacin-induced gastric ulcer rat model was used. The roles of biomolecules such as MPO, PGE2, pro- and anti-inflammatory cytokines, growth factors, caspase-3, NO, K(+)ATP channels, and α 2-receptors were investigated. Violacein exhibited significant gastroprotective effect against indomethacin-induced lesions, while pretreatment with L-NAME and glibenclamide (but not with NEM or yohimbine) was able to reverse this action. Pretreatment with violacein also restored cNOS level to normal and led to attenuation of enhanced apoptosis and gastric microvascular permeability. Our results suggest that violacein provides a significant gastroprotective effect in an indomethacin-induced ulcer model through the maintenance of some vital protein molecules, and this effect appears to be mediated, at least in part, by endogenous prostaglandins, NOS, K(+)ATP channel opening, and inhibition of apoptosis and gastric microvascular permeability.

Antifeedant, larvicidal and growth inhibitory bioactivities of novel polyketide metabolite isolated from Streptomyces sp. AP-123 against Helicoverpa armigera and Spodoptera litura.

BACKGROUND: Considerable attention has been paid to actinomycetes, especially the secondary metabolites obtained from Streptomyces species, as the best alternatives to chemicals as biological control agents for polyphagous pests such as Helicoverpa armigera and Spodoptera litura. On the basis of their novel biocontrol attributes, novel polyketide metabolite isolated from marine Streptomyces sp. AP-123 exhibited significant antifeedant, larvicidal and growth inhibitory activities against polyphagous pests. RESULTS: Leaf disc no-choice method was used for the insect bioassay. The polyketide metabolite presented significant antifeedant activities against H. armigera (78.51%) and S. litura (70.75%) at 1000 ppm concentration. The metabolite also exhibited high larvicidal activities against H. armigera (63.11%) and S. litura (58.22%) and the LC50 values were 645.25 ppm for H. armigera and 806.54 ppm for S. litura. The metabolite also prolonged the larval-pupal duration of the insects at all the tested concentrations. CONCLUSIONS: The activities of the polyketide metabolite were concentration dependent for both the insects therefore it could be used as an agent to prepare new pesticidal formulations.

Role of Polyphenols in Alleviating Alzheimer's Disease: A Review.

Alzheimer's Disease (AD) is a successive neurodegenerative disorder in the aged population. Many chemicals and phytochemicals are used to treat AD. Polyphenols which occur widely in various fruits, vegetables, beverages, and some other plant sources are gaining importance in AD treatment. Polyphenols comprise various subcategories, such as phenolic acids, lignans, tannins, stilbenes, hydroxybenzoic acid, hydroxycinnamic acid, and flavonoids. These compounds, as sole entities or in combination, can be used for treating AD because they have an abundance of antioxidants that are reported to be effective in free radical scavenging, metal ion chelating, and anti-inflammatory activities. Polyphenols of various plant origins have been studied, and these have been supported by in vitro assays and in vivo studies in rodents. These molecules protect neurons against oxidative stress and deposition of amyloid-ß (Aß) and tau proteins which play a vital role in the pathogenesis of AD. Consumption of wine and other foods rich in polyphenols has a beneficial effect on the neuronal signaling pathways, playing a vital role in shielding neuronal cells from neurodegeneration. Their ability to reduce free radicals and chelate metals are of great advantage. In this review, we highlight the various polyphenols that inhibit neuronal damage and progression of AD while also providing a cure. Some of the polyphenols covered are hesperidin, resveratrol, curcumin, catechin, kaempferol, and quercetin. The mechanisms of the actions of three polyphenols are also elaborated.

Antimicrobial activity of sesquiterpene lactones isolated from traditional medicinal plant, Costus speciosus (Koen ex.Retz.) Sm.

BACKGROUND: Costus speciosus (Koen ex.Retz.) Sm (Costaceae) is an Indian ornamental plant which has long been used medicinally in traditional systems of medicine. The plant has been found to possess diverse pharmacological activities. Rhizomes are used to treat pneumonia, rheumatism, dropsy, urinary diseases, jaundice, skin diseases and leaves are used to treat mental disorders. METHOD: Antibacterial and antifungal activities were tested using Disc diffusion method and Minimum Inhibitory Concentration (MIC). Column chromatography was used to isolate compounds from hexane extract. X-ray crystallography technique and GC-MS analysis were used to identify the compounds RESULTS: Antibacterial and antifungal activities were observed in hexane, chloroform, ethyl acetate and methanol extracts. Hexane extract of C.speciosus showed good activity against tested fungi also. Two sesquiterpenoid compounds were isolated (costunolide and eremanthin) from the hexane extract. Both the compounds did not inhibit the growth of tested bacteria. But, both the compounds inhibited the tested fungi. The compound costunolide showed significant antifungal activity. The MIC values of costunolide were; 62.5 µg/ml against Trichophyton mentagrophytes, 62. µg/ml against T. simii, 31.25 µg/ml against T. rubrum 296, 62.5 µg/ml against T. rubrum 57, 125 µg/ml against Epidermophyton floccosum, 250 µg/ml against Scopulariopsis sp, 250 µg/ml against Aspergillus niger, 125 µg/ml against Curvulari lunata, 250 µg/ml against Magnaporthe grisea. CONCLUSION: Hexane extract showed promising antibacterial and antifungal activity. The isolated compound costunolide showed good antifungal activity.