Fatty Acid Profile and Antimicrobial Activity of Rubus ulmifolius Schott Extracts Against Cariogenic Bacterium Streptococcus mutans

Abstract: The wild edible species Rubus ulmifolius is normally known as a source of several functional- natural compounds used in the traditional diet in several parts of the world. At present, few data are available in the literature about the biological property of its leaves, normally rich in phenolic acids, fatty acids, and other organic compounds with potential antimicrobial activity. Following this hypothesis, we have investigated the antibacterial activity of different dried leaved extracts against the main cariogenic bacterium, Streptococcus mutans. Standard antimicrobial-antibiofilm methods (MIC, MBC, MBIC) were performed to evaluate each extract's antimicrobial profile. In addition, the fatty acids (FA) quali-quantitative profile of R. ulmifolius leave extracts was assessed by reversed-phase HPLC-DAD/ELSD analysis. The results showed that the behavior of this bacterium with different extracts was strictly related to extraction method type, even though it was not related to fatty acid amount and composition, in fact, all the extracts showed similar, qualitative FA patterns, characterized by a concentration in the range from (25 to 36) % of saturated compounds. The methanolic extract showed the better result as antibacterial MIC 6.25 %. These preliminary results encourage further studies for the use of R. ulmifolius in mouthwashes or toothpaste with great anticaries activity

Synergistic Activity of the Human Lactoferricin-Derived Peptide hLF1-11 in Combination with Caspofungin against Candida Species

The present study describes a synergistic effect between a conventional antifungal drug, caspofungin, and a synthetic peptide derived from human lactoferrin, hLF1-11, against Candida species. These yeasts are able to cause severe systemic fungal infections in immunocompromised hosts.Candida species are the main fungal opportunistic pathogens causing systemic infections that are often associated with drug resistance and biofilm production on medical devices. The pressing need for new antifungal agents led to an increased interest in the use of combination therapies. The present study was aimed at investigating potential synergistic activity of the human lactoferrin-derived hLF1-11 peptide with caspofungin against caspofungin-resistant or -susceptible C. albicans, C. parapsilosis, and C. glabrata strains. Synergism was evaluated by the checkerboard assay, measuring cellular metabolic activity against Candida planktonic and sessile cells. A fractional inhibitory concentration (FIC) index of <= 0.5 was interpreted as synergy. Synergism was evaluated by killing assays on planktonic cells. A cell viability assay was performed with biofilm formation inhibition and preformed biofilm. Synergy for killing and viability assays was defined as a >= 2-log-CFU/mL reduction in comparison with the most active constituent. hLF1-11 and caspofungin exerted (i) synergistic effects against planktonic cells of all the tested strains, yielding drastic caspofungin MIC reduction, (ii) synergistic effects on the inhibition of biofilm formation against biofilm producer strains, yielding caspofungin BIC reduction, and (iii) synergistic effects on preformed biofilm assessed by measuring metabolic activity (FIC range, 0.28 to 0.37) against biofilm-producing strains and by cell viability assay in C. albicans SC5314. The synergistic effect observed between caspofungin and hLF1-11 against Candida spp. is of potential clinical relevance, representing a promising novel approach to target caspofungin-resistant Candida species infections. Further studies elucidating the mechanisms of action of such a synergistic effect are needed. IMPORTANCE The present study describes a synergistic effect between a conventional antifungal drug, caspofungin, and a synthetic peptide derived from human lactoferrin, hLF1-11, against Candida species. These yeasts are able to cause severe systemic fungal infections in immunocompromised hosts. In addition, they can form biofilms in medical implanted devices. Recently, caspofungin-resistant Candida strains have emerged, thus highlighting the need to develop different therapeutic strategies. In in vitro studies, this drug combination is able to restore sensitivity to caspofungin in caspofungin-resistant strains of Candida species, both in free-living cells and in cells organized in biofilms. This synergism could represent a promising novel approach to target infections caused by caspofungin-resistant Candida species

Substitution Effects on the Optoelectronic Properties of Coumarin Derivatives

Coumarin derivatives have gathered major attention largely due to their versatile utility in a wide range of applications. In this framework, we report a comparative computational investigation on the optoelectronic properties of 3-phenylcoumarin and 3-heteroarylcoumarin derivatives established as enzyme inhibitors. Specifically, we concentrate on the variation in the optoelectronic characteristics for the hydroxyl group substitutions within the coumarin moiety. In order to realize our aims, all-electron density functional theory and time dependent density functional theory calculations were performed with a localized Gaussian basis-set matched with a hybrid exchange–correlation functionals. Molecular properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, vertical ionization (IEV) and electron affinity energies, absorption spectra, quasi-particle gap, and exciton binding energy values are examined. Furthermore, the influence of solvent on the optical properties of the molecules is considered. We found a good agreement between the experimental (8.72 eV) and calculated (8.71 eV) IEV energy values for coumarin. The computed exciton binding energy of the investigated molecules indicated their potential optoelectronics application

Euphorbia characias: Phytochemistry and Biological Activities

The aim of this review is to summarize all the compounds identified and characterized from Euphorbia characias, along with the biological activities reported for this plant. Euphorbia is one of the greatest genera in the spurge family of Euphorbiaceae and includes different kinds of plants characterized by the presence of milky latex. Among them, the species Euphorbia characias L. is an evergreen perennial shrub widely distributed in Mediterranean countries. E. characias latex and extracts from different parts of the plant have been extensively studied, leading to the identification of several chemical components such as terpenoids, sterol hydrocarbons, saturated and unsaturated fatty acids, cerebrosides and phenolic and carboxylic acids. The biological properties range between antioxidant activities, antimicrobial, antiviral and pesticidal activities, wound-healing properties, anti-aging and hypoglycemic properties and inhibitory activities toward target enzymes related to different diseases, such as cholinesterases and xanthine oxidase. The information available in this review allows us to consider the plant E. characias as a potential source of compounds for biomedical research

Comparison of different microbiological procedures for the diagnosis of Pneumocystis jirovecii pneumonia on bronchoalveolar-lavage fluid

Background: The current diagnostic gold standard for Pneumocystis jirovecii is represented by microscopic visualization of the fungus from clinical respiratory samples, as bronchoalveolar-lavage fluid, defining "proven" P. jirovecii pneumonia, whereas qPCR allows defining "probable" diagnosis, as it is unable to discriminate infection from colonization. However, molecular methods, such as end-point PCR and qPCR, are faster, easier to perform and interpret, thus allowing the laboratory to give back the clinician useful microbiological data in a shorter time. The present study aims at comparing microscopy with molecular assays and beta-D-glucan diagnostic performance on bronchoalveolar-lavage fluids from patients with suspected Pneumocystis jirovecii pneumonia. Bronchoalveolar-lavage fluid from eighteen high-risk and four negative control subjects underwent Grocott-Gomori's methenamine silver-staining, end-point PCR, RT-PCR, and beta-D-glucan assay.Results: All the microscopically positive bronchoalveolar-lavage samples (50%) also resulted positive by end-point and real time PCR and all, but two, resulted positive also by beta-D-glucan quantification. End-point PCR and RT-PCR detected 10 (55%) and 11 (61%) out of the 18 samples, respectively, thus showing an enhanced sensitivity in comparison to microscopy. All RT-PCR with a Ct <27 were confirmed microscopically, whereas samples with a Ct >= 27 were not.Conclusions: Our work highlights the need of reshaping and redefining the role of molecular diagnostics in a peculiar clinical setting, like P. jirovecii infection, which is a rare but also severe and rapidly progressive clinical condition affecting immunocompromised hosts that would largely benefit from a faster diagnosis. Strictly selected patients, according to the inclusion criteria, resulting negative by molecular methods could be ruled out for P. jirovecii pneumonia

The N-Terminus of Human Lactoferrin Displays Anti-biofilm Activity on Candida parapsilosis in Lumen Catheters

Candida parapsilosis is a major cause of hospital-acquired infection, often related to parenteral nutrition administered via catheters and hand colonization of health care workers, and its peculiar biofilm formation ability on plastic surfaces. The mortality rate of 30% points to the pressing need for new antifungal drugs. The present study aimed at analyzing the inhibitory activity of the N-terminal lactoferrin-derived peptide, further referred to as hLF 1-11, against biofilms produced by clinical isolates of C. parapsilosis characterized for their biofilm forming ability and fluconazole susceptibility. hLF 1-11 anti-biofilm activity was assessed in terms of reduction of biofilm biomass, metabolic activity, and observation of sessile cell morphology on polystyrene microtiter plates and using an in vitro model of catheter-associated C. parapsilosis biofilm production. Moreover, fluctuation in transcription levels of genes related to cell adhesion, hyphal development and extracellular matrix production upon peptide exposure were evaluated by quantitative real time RT-PCR. The results revealed that hLF 1-11 exhibits an inhibitory effect on biofilm formation by all the C. parapsilosis isolates tested, in a dose-dependent manner, regardless of their fluconazole susceptibility. In addition, hLF 1-11 induced a statistically significant dose-dependent reduction of preformed-biofilm cellular density and metabolic activity at high peptide concentrations only. Interestingly, when assessed in a catheter lumen, hLF 1-11 was able to induce a 2-log reduction of sessile cell viability at both the peptide concentrations used in RPMI diluted in NaPB. A more pronounced anti-biofilm effect was observed (3.5-log reduction) when a 10% glucose solution was used as experimental condition on both early and preformed C. parapsilosis biofilm. Quantitative real time RT-PCR experiments confirmed that hLF 1-11 down-regulates key biofilm related genes. The overall findings suggest hLF 1-11 as a promising candidate for the prevention of C. parapsilosis biofilm formation and to treatment of mature catheter-related C. parapsilosis biofilm formation

Advances in Sardinian Withania somnifera (L.) Dunal crops through phytochemical and biological approaches

Withania somnifera (L.) Dunal is widely used in the Indian traditional system of medicine to promote general health, wellness, and longevity. Its pharmacological properties are attributed to a group of molecules called withanolides, among which Withaferin A holds great interest for its anti-carcinogenic action. For this reason, numerous studies in recent years have focused on different metabolic or genetic engineering solutions to increase its yield. Here, we present the Sardinian chemotype of Withania somnifera as a potential crop for the extraction of Withaferin A. W. somnifera was cultivated from Sardinian wild germplasm collected in the northeast of the island. After 18 months, the leaves and the roots were collected and their methanolic extract was analyzed by HPLC. 0.3 mg/g DW of Withanolide A (WA), 1.0 mg/g DW of Withanolide B (WB) and 17.7 mg/g DW of Withaferin A (WF) were detected in the leaf sample, while lower values were detected in the roots (0.1 mg/g WF, 0.3 WA mg/g, 0.1 mg/g WB, 0.2 mg/g WO). This research not only confirms the high Withaferin A content found in the wild population leaves, but shows how they are reproducible in cultivated specimens, highlighting Sardinian W. somnifera leaves as a potential source of high-content Withaferin A products. Finally, we focused on the leaves extract by characterizing the phenolic and flavonoid content, as well as the in-vitro antioxidant capacity by DPPH and ABTS assays, revealing a significant amount of phenolic compounds and a related free radical scavenging activity. The leaves extract was further characterized for its anti-aging properties for potential cosmetic application, by the inhibition of tyrosinase, elastase, and collagenase enzymes

Hydroxy-3-Phenylcoumarins as Multitarget Compounds for Skin Aging Diseases: Synthesis, Molecular Docking and Tyrosinase, Elastase, Collagenase and Hyaluronidase Inhibition, and Sun Protection Factor

Skin aging is a progressive biological process of the human body, and it is not only time-dependent. Differently substituted 3-phenylcoumarins proved to efficiently inhibit tyrosinase. In the current work, new substitution patterns have been explored, and the biological studies were extended to other important enzymes involved in the processes of skin aging, as elastase, collagenase and hyaluronidase. From the studied series, five compounds presented inhibitory activity against tyrosinase, one compound against elastase, eight compounds against collagenase and two compounds against hyaluronidase, being five compounds dual inhibitors. The 3-(4 '-Bromophenyl)-5,7-dihydroxycoumarin (1) and 3-(3 '-bromophenyl)-5,7-dihydroxycoumarin (2) presented the best profiles against tyrosinase (IC50 = 1.05 mu M and 7.03 mu M) and collagenase (IC50 = 123.4 mu M and 110.4 mu M); the 3-(4 '-bromophenyl)-6,7-dihydroxycoumarin (4) presented a good inhibition against tyrosinase and hyaluronidase; the 3-(3 '-bromophenyl)-6,7-dihydroxycoumarin (5) showed an effective tyrosinase and elastase inhibition; and 6,7-dihydroxy-3-(3 '-hydroxyphenyl)coumarin (11) presented a dual profile inhibition against collagenase and hyaluronidase. Furthermore, considering the overall activities tested, compounds 1 and 2 proved to be the most promising anti-aging compounds. These compounds also showed to have a photo-protective effect, without being cytotoxic to human skin keratinocyte cells. To predict the binding site with the target enzymes, computational studies were also carried out

Promising inhibition of diabetes-related enzymes and antioxidant properties of Ptilostemon casabonae leaves extract

Type 2 diabetes (T2D) is a progressive metabolic disorder of glucose metabolism. One of the therapeutic approaches for the treatment of T2D is reducing postprandial hyperglycaemia through inhibition of the digestive enzymes α-glucosidase and α-amylase. In this context, aimed at identifying natural products endowed with anti-T2D potential, we focused on Ptilostemon casabonae (L.) Greuter, a species belonging to Asteraceae family. Enzymatic inhibition, antioxidant activity, phenolic composition and cellular assays were performed. This study revealed that the P. casabonae hydroalcoholic extract exerts a potent inhibitory activity against α-glucosidase. This activity is supported by an antioxidant effect, preventing ROS formation in a stressed cellular system. HPLC-PDA-MS/MS analysis, revealed a complex polyphenolic fraction. Among the tested pure compounds, 1,5-dicaffeoylquinic acid, apigenin and rutin displayed good α-glucosidase inhibitory activity. Our study suggested new potential of P. casabonae encouraging us to further testing the possible therapeutic potential of this extract