Oxidative Stress Response Mechanisms Sustain the Antibacterial and Antioxidant Activity of Quercus ilex.

The development of new natural antibiotics is considered as the heart of several investigations in the nutraceutical field. In this work, leaves of Quercus ilex L. treated by tropospheric ozone (O3) and nitrogen (N) deposition, exhibited a clear antimicrobial efficacy against five multi-drug resistant (MDR) bacterial strains (two gram-positive and three gram-negative). Under controlled conditions, it was studied how simulated N deposition influences the response to O3 and the antibacterial and antioxidant activity, and antioxidant performance. The extraction was performed by ultra-pure acetone using two different steps. A higher antioxidant activity was measured in the presence of interaction between O3 and N treatments on Quercus leaves. At the same time, all organic extracts tested have shown bacteriostatic activity against all the tested strains with a MIC comprised between 9 and 4 micrograms/mL, and a higher antioxidant efficacy shown by spectrophotometric assay. Stronger antimicrobial activity was found in the samples treated with O3, whereas N-treated plants exhibited an intermediate antibacterial performance. This performance is related to the stimulation of the non-enzymatic antioxidant system induced by the oxidative stress, which results in an increase in the production of antimicrobial bioactive compounds.

Efficacy and safety of direct oral anticoagulants in splanchnic vein thrombosis: a pooled analysis of literature studies.

BACKGROUND: Limited evidence is available on management of splanchnic vein thrombosis (SVT). OBJECTIVES: This study aimed to evaluate safety and efficacy of direct oral anticoagulants (DOACs) for SVT treatment. METHODS: Studies were systematically searched in the PubMed, Web of Science, and Scopus databases according to PRISMA guidelines. We assessed any recanalization, full recanalization, recurrence, mortality, and major bleeding as outcomes of interest. Results were reported as weighted mean prevalence (WMP) with 95% CI. Subgroup analyses and meta-regressions have been performed to address heterogeneity and adjust for potential confounders. RESULTS: We included a total of 16 studies (17 datasets) on 648 patients with SVT treated with DOACs. We found any recanalization in 60.3% (95% CI: 41.8%-76.3%; I2 = 84.9%; P < .001) and full recanalization in 51.7% (95% CI: 36.0%-67.0%; I2 = 87.4%; P < .001). Recurrent venous thromboembolism occurred in 2.8% (95% CI: 1.4%-5.9%; I2 = 0%; P = .787) and death in 3.4% (95% CI: 1.6%-7.3%; I2 = 13.2%; P = .318) of patients. Major bleeding was reported by 5.8% (95% CI: 3.7%-8.9%; I2 = 29.2%; P = .125) of patients. Results were consistent when separately analyzing prospective studies, retrospective studies, studies on cirrhotic patients, and studies enrolling patients with portal vein thrombosis. Meta-regression analyses showed that an increasing age and cancer impacted the rate of recanalization. Cirrhosis was associated with a higher rate of major bleeding and mortality. CONCLUSION: The results of the present study, mostly based on observational studies, suggest good safety and efficacy profiles of DOACs in patients with SVT. Randomized studies are needed to corroborate our findings.

Chemical Composition of Salvia fruticosa Mill. Essential Oil and Its Protective Effects on Both Photosynthetic Damage and Oxidative Stress in Conocephalum conicum L. Induced by Environmental Heavy Metal Concentrations.

The genus Salvia L., belonging to the Lamiaceae family, contains more than 900 species distributed in various parts of the world. It is a genus containing aromatic plants used both in the culinary field and above all in the cosmetic area to produce several perfumes. Salvia fruticosa Mill., notoriously known as Greek Salvia, is a plant used since ancient times in traditional medicine, but today cultivated and used in various parts of Europe and Africa. Polar and apolar extracts of this plant confirmed the presence of several metabolites such as abietane and labdane diterpenoids, triterpenoids, steroids, and some flavonoids, causing interesting properties such as sedative, carminative, and antiseptic, while its essential oils (EOs) are mainly characterized by compounds such as 1,8-cineole and camphor. The aim of this work concerns the chemical analysis by GC and GC-MS, and the investigation of the biological properties, of the EO of S. fruticosa plants collected in eastern Sicily. The gas-chromatographic analysis confirmed the presence of 1,8-cineole (17.38%) and camphor (12.81%), but at the same time, also moderate amounts of α-terpineol (6.74%), ß-myrcene (9.07%), camphene (8.66%), ß-pinene (6.55%), and α-pinene (6.45%). To study the protective effect of EOs from S. fruticosa (both the total mixture and the individual compounds) on possible damage induced by heavy metals, an in vitro system was used in which a model organism, the liverwort Conocephalum conicum, was subjected to the effect of a mix of heavy metals (HM) prepared using values of concentrations actually measured in one of the most polluted watercourses of the Campania region, the Regi Lagni. Finally, the antioxidant response and the photosynthetic damage were examined. The exogenous application of the EO yields a resumption of the oxidative stress induced by HM, as demonstrated by the reduction in the Reactive Oxygen Species (ROS) content and by the increased activity of antioxidant enzyme catalase (CAT) and glutathione-S-transferase (GST). Furthermore, plants treated with HMs and EO showed a higher Fv/Fm (maximal quantum efficiency of PSII in the dark) with respect to HMs-only treated ones. These results clearly indicate the protective capacity of the EO of S. fruticosa against oxidative stress, which is achieved at least in part by modulating the redox state through the antioxidant pathway and on photosynthetic damage.

Antimicrobial and antioxidant activity of proteins from Feijoa sellowiana Berg. fruit before and after in vitro gastrointestinal digestion.

In this paper we report for the first time a method for the extraction of the protein fraction from Feijoa sellowiana Berg. fruit and its electrophoretic analysis. In addition we analyzed the protein fraction for its antioxidant activity and its effectiveness against different Gram-positive and Gram-negative bacteria both as American type culture collection (ATCC) standard and clinically isolated strains. Both antimicrobial and antioxidant activity resulted stronger respect to that previously obtained for the acetonic extract from the same fruit. Further, we study both activities also on the product of in vitro gastrointestinal digestion of F. sellowiana fruit proteins. The results showed that in vitro gastrointestinal digestion increased 10 fold the antioxidant activity, while the antimicrobial activity, tested only on ATCC strains, resulted from 2 to 4 fold increased. MTT assays showed the non-toxicity of these proteins both before and after digestion.

Salicylic Acid and Melatonin Alleviate the Effects of Heat Stress on Essential Oil Composition and Antioxidant Enzyme Activity in Mentha × piperita and Mentha arvensis L.

The aim of this study was to evaluate changes in the chemical profile of essential oils and antioxidant enzymes activity (catalase CAT, superoxide dismutase SOD, Glutathione S-transferases GST, and Peroxidase POX) in Mentha × piperita L. (Mitcham variety) and Mentha arvensis L. (var. piperascens), in response to heat stress. In addition, we used salicylic acid (SA) and melatonin (M), two brassinosteroids that play an important role in regulating physiological processes, to assess their potential to mitigate heat stress. In both species, the heat stress caused a variation in the composition of the essential oils and in the antioxidant enzymatic activity. Furthermore both Salicylic acid (SA) and melatonin (M) alleviated the effect of heat stress.

Protamine-like proteins have bactericidal activity. The first evidence in Mytilus galloprovincialis.

The major acid-soluble protein components of the mussel Mytilus galloprovincialis sperm chromatin consist of the protamine-like proteins PL-II, PL-III and PL-IV, an intermediate group of sperm nuclear basic proteins between histones and protamines. The aim of this study was to investigate the bactericidal activity of these proteins since, to date, there are reports on bactericidal activity of protamines and histones, but not on protamine-like proteins. We tested the bactericidal activity of these proteins against Gram-positive bacteria: Enterococcus faecalis and two different strains of Staphylococcus aureus, as well as Gram-negative bacteria: Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella typhmurium, Enterobacter aerogenes, Enterobacter cloacae, and Escherichia coli. Clinical isolates of the same bacterial species were also used to compare their sensitivity to these proteins. The results show that Mytilus galloprovincialis protamine-like proteins exhibited bactericidal activity against all bacterial strains tested with different minimum bactericidal concentration values, ranging from 15.7 to 250 µg/mL. Furthermore, these proteins were active against some bacterial strains tested that are resistant to conventional antibiotics. These proteins showed very low toxicity as judged by red blood cell lysis and viability MTT assays and seem to act both at the membrane level and within the bacterial cell. We also tested the bactericidal activity of the product obtained from an in vitro model of gastrointestinal digestion of protamine-like proteins on a Gram-positive and a Gram-negative strain, and obtained the same results with respect to undigested protamine-like proteins on the Gram-positive bacterium. These results provide the first evidence of bactericidal activity of protamine-like-proteins.

Acetonic Extract from the Feijoa sellowiana Berg. Fruit Exerts Antioxidant Properties and Modulates Disaccharidases Activities in Human Intestinal Epithelial Cells.

Feijoa sellowiana fruit has been shown to possess various biological activities, such as anti-bacterial and anti-cancer properties, in a variety of cellular models, but its activity on human intestinal epithelial cells has never been tested. The purpose of this study was to investigate the effects of the acetonic extract of F. sellowiana fruits on the viability, membrane peroxidation, disaccharidases activities and proliferation of in vitro models of human intestinal epithelial cells. To obtain this goal, Caco-2 and HT-29 cells were exposed to the acetonic extract for 24 h. Cell proliferation, viability, lactase and sucrase-isomaltase activity and H2 O2 -induced membrane lipid peroxidation were tested. We found that, compared to control conditions, the acetonic extract significantly increased lactase and sucrase-isomaltase activity in Caco-2, but not HT-29, cells, decreased proliferation, had no effects on viability and restored lipid peroxidation in both cell models. This study suggests that the acetonic extract improves lactase and sucrase-isomaltase activity, inhibits cell proliferation, have no cytotoxic effects and prevent lipid peroxidation of intestinal epithelial cells. These effects may be exploited in case of disaccharidases deficit and also as an adjuvant treatment of diseases related to oxidative stress. Copyright © 2016 John Wiley & Sons, Ltd.

Antiproliferative, antibacterial and antifungal activity of the lichen Xanthoria parietina and its secondary metabolite parietin.

Lichens are valuable natural resources used for centuries throughout the world as medicine, food, fodder, perfume, spices and dyes, as well as for other miscellaneous purposes. This study investigates the antiproliferative, antibacterial and antifungal activity of the acetone extract of the lichen Xanthoria parietina (Linnaeus) Theodor Fries and its major secondary metabolite, parietin. The extract and parietin were tested for antimicrobial activity against nine American Type Culture Collection standard and clinically isolated bacterial strains, and three fungal strains. Both showed strong antibacterial activity against all bacterial strains and matched clinical isolates, particularly against Staphylococcus aureus from standard and clinical sources. Among the fungi tested, Rhizoctonia solani was the most sensitive. The antiproliferative effects of the extract and parietin were also investigated in human breast cancer cells. The extract inhibited proliferation and induced apoptosis, both effects being accompanied by modulation of expression of cell cycle regulating genes such as p16, p27, cyclin D1 and cyclin A. It also mediated apoptosis by activating extrinsic and intrinsic cell death pathways, modulating Tumor Necrosis Factor-related apoptosis-inducing ligand (TRAIL) and B-cell lymphoma 2 (Bcl-2), and inducing Bcl-2-associated agonist of cell death (BAD) phosphorylation. Our results indicate that Xanthoria parietina is a major potential source of antimicrobial and anticancer substances.