Antimicrobial, antioxidant, anti-inflammatory activities and phytoconstituents of extracts from the roots of Dissotis thollonii Cogn. (Melastomataceae)

Abstract Background Dissotis thollonii Cogn. belonging to the Malastomataceae family is used in the West Region of Cameroon for the treatment of inflammation, kidney diseases, pregnancy control and sinusitis. Despite the traditional use of this plant, no scientific report or information was found in the literature regarding neither its biological activity nor its chemical constituents. Aim of the study The present work was designed to determine the antimicrobial, antioxidant and anti-inflammatory activities of different extracts of the roots of D. thollonii Cogn. as well as the isolation and identification of the chemical constituents of this plant. Materials and methods The tests for antimicrobial, antioxidant and anti-inflammatory activities were performed over the MeOH, EtOAc, n-BuOH and aqueous extracts. Compounds were isolated from EtOAc and n-BuOH extracts of the roots of D. thollonii Cogn. through column chromatography and their structures were determined by means of NMR and MS analysis, and published data. Results According to the antimicrobial and antioxidant assays, the EtOAc and n-BuOH extracts were submitted to further separation and purification. This led to the isolation of twelve compounds identified as 3,3′-di- O -methylellagic acid 4′- O-β -D-xylopyranoside 1 , 3- O -methylellagic acid 4′- O-β -D-arabinopyranoside 2 , casuarinin 3 , betulinic acid 4 , β -sitosterol-3- O -D-glucopyranosyl-6′-mirystate 5 , cellobiosylsterol 6 , β -sitosterol 7 , β -sitosterol-3- O-β -D-glucopyranoside 8, arjunolic acid 9 , 3,3′-di- O -methylellagic acid 10 , ellagic acid 11 , and 3,3′-di- O -methylellagic acid 4′- O - β -D-glucopyranoside 12 . The EtOAc extract was the only antimicrobial active sample [diameter of the zone of inhibition (DZI) of 10 mm against Staphyloccocus aureus ] among all the tested extracts. The analysis of fractions of this extract revealed the presence of bioactive compounds with a described antimicrobial activity such as β -sitosterol, β -sitosterol-3- O-β -D-glucopyranoside and arjunolic acid. By using Trolox as the standard drug, all extracts showed antioxidant activity against DPPH in the following order of scavenging ability: Trolox > nBuOH > EtOAc > MeOH > WE (water extract). The ABTS •+ scavenging ability was similar to that found for the DPPH assay, being Trolox > n-BuOH > MeOH > EtOAc > WE. Along with the DPPH and ABTS assays, the FRAP assay showed the scale n-BuOH > MeOH > WE > EtOAc. The phytochemical study of the EtOAc and n-BuOH extracts revealed the presence of important known antioxidant compounds such as ellagic acid derivatives, arjunolic acid, betulinic acid and β -sitosterol. The anti-inflammatory properties of D. thollonii extracts were investigated using RAW 264.7 murine macrophage cells. The MeOH extract reduced the stimulated NO production in a concentration-dependent manner. 86% reduction was observed at the highest tested concentration of 100 μg/ml (IC 50 = 5.9 μg/ml). The n-BuOH extract showed higher dose dependent reduction of NO formation (IC 50 = 6.5 μg/ml) than the EtOAc extract (IC 50 = 18.1 μg/ml), whereas the water extract had no significant influence on the NO production. All the extracts did not have any influence on the macrophage viability. The phytochemical investigation of the EtOAc and n-BuOH extracts revealed that the main compounds identified do have potent anti-inflammatory properties. Conclusion The biological and phytochemical characterization of the root extracts of D. thollonii validates the use of this plant for the treatment of inflammation and sinusitis, thus providing evidence that this plant extracts, as well as some of the isolated compounds, might be potential sources of antioxidant and anti-inflammatory drugs

Study of the lineshape of the chi(c1) (3872) state

A study of the lineshape of the chi(c1) (3872) state is made using a data sample corresponding to an integrated luminosity of 3 fb(-1) collected in pp collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate chi(c1)(3872) and psi(2S) mesons from b-hadron decays are selected in the J/psi pi(+)pi(-) decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the chi(c1 )(3872) and psi(2S) states, Delta m, and the width of the chi(c1 )(3872) state, Gamma(Bw), are determined to be (Delta m=185.598 +/- 0.067 +/- 0.068 Mev,)(Gamma BW=1.39 +/- 0.24 +/- 0.10 Mev,) where the first uncertainty is statistical and the second systematic. Using a Flatte-inspired model, the mode and full width at half maximum of the lineshape are determined to be (mode=3871.69+0.00+0.05 MeV.)(FWHM=0.22-0.04+0.13+0.07+0.11-0.06-0.13 MeV, ) An investigation of the analytic structure of the Flatte amplitude reveals a pole structure, which is compatible with a quasibound D-0(D) over bar*(0) state but a quasivirtual state is still allowed at the level of 2 standard deviations

Measurement of the CKM angle γγ in B±→DK±B^\pm\to D K^\pm and B±→Dπ±B^\pm \to D π^\pm decays with D→KS0h+h−D \to K_\mathrm S^0 h^+ h^-

A measurement of $CP$-violating observables is performed using the decays $B^\pm\to D K^\pm$ and $B^\pm\to D \pi^\pm$, where the $D$ meson is reconstructed in one of the self-conjugate three-body final states $K_{\mathrm S}\pi^+\pi^-$ and $K_{\mathrm S}K^+K^-$ (commonly denoted $K_{\mathrm S} h^+h^-$). The decays are analysed in bins of the $D$-decay phase space, leading to a measurement that is independent of the modelling of the $D$-decay amplitude. The observables are interpreted in terms of the CKM angle $\gamma$. Using a data sample corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$ collected in proton-proton collisions at centre-of-mass energies of $7$, $8$, and $13\,\text{TeV}$ with the LHCb experiment, $\gamma$ is measured to be $\left(68.7^{+5.2}_{-5.1}\right)^\circ$. The hadronic parameters $r_B^{DK}$, $r_B^{D\pi}$, $\delta_B^{DK}$, and $\delta_B^{D\pi}$, which are the ratios and strong-phase differences of the suppressed and favoured $B^\pm$ decays, are also reported

Metallo-\u3b2-lactamase expression confers an advantage to Pseudomonas aeruginosa isolates compared with other \u3b2-lactam resistance mechanisms, favoring the prevalence of metallo-\u3b2-lactamase producers in a clinical environment.

The Pseudomonas aeruginosa isolate TS-832035 exhibited a high level resistance to carbapenems for the contemporary presence of two independent mechanisms: the production of a carbapenemase, coded by a blaVIM-1 determinant carried by a class 1 integron In70.2 and the lack of the OprD porin. We compared TS-832035 with a strictly related isolate, TS-103 that didn\u2019t carry In70.2. These experiments highlighted a significant in vitro fitness cost associated with the integron. On the contrary, none of the resistance determinants other than the blaVIM-1seemed to confer a real selective advantage to its host. Comparison of these results with the in vivo behaviour, showing that the In70.2-carrying isolates largely prevailed over the In70.2-lacking ones, evidence the need to investigate accurately the causes of their large distribution, as possible soft spots could exist in the ability of their hosts to adapt to the hospital settings

Analysis of methicillin-resistant Staphylococcus aureus isolates from catheter infections isolated in a large Italian hospital.

Objective: Twelve methicillin-resistant Staphylococcus aureus (MRSA) isolates from nosocomial catheter infections were studied. We determined their antibiotic susceptibility pattern (penicillin, oxacillin, erythromycin, tetracycline, clindamycin, telithromycin, gentamycin, ciprofloxacin, quinupristin-dalfopristin, rifampin, vancomycin and linezolid), and the presence of the genetic determinants of antibiotic resistance. To evaluate their genetic variability, isolates were subjected to multilocus sequence typing (MLST), SmaI macrorestriction/PFGE analysis and to staphylococcal chromosomal cassette/cassette chromosome recombinase (SCCmec/ccr) complex type determination. Methods: The determination of the MICs was performed following the Clinical Laboratory Standards Institute guidelines. Genetic determinants of antibiotic resistance were screened by PCR, using specific primer set described in the literature, while a standard multiplex PCR protocol was used to assess the SCCmec and ccrAB complex type. MLST, SmaI macrorestriction of chromosomal DNA and PFGE analysis were performed according to standard procedures. Results: An almost complete correlation was found between phenotypes and genotypic traits of antibiotic resistance. A major group of ten strains bore the SCCmec type I structure and showed the common sequence type st228. Among this group, only seven strains had a SmaI macrorestriction profile matching that of the archaic pandemic clone. One strain, resistant to all antibiotics but vancomycin, was st239 and SCCmec type IIIA. However, its SmaI macrorestriction profile was not related to that of the pandemic clones having a type IIIA SCCmec. It was not possible to assign the SCCmec type of the remaining two strains. They presented very rare multilocus sequence types, one being st83 and the other st395, and possessed a SmaI macrorestriction profile that was not related to that any of the known pandemic clones. Conclusions: i) An extremely resistant strain belonging to st239 was isolated and characterized; ii) in the st228 group, SmaI macrorestriction analysis was able to identify different subclones, showing an higher discriminatory power than MLST; iii) the analysis of the SCCmec/ccrAB complex of two strains with rare sequence types was not possible with the multiplex PCR methodology used, indicating the possible presence of new variants of the SCCmec

Erythromycin resistance in Italian Isolates of Streptococcus pyogenes and Correlations with Pulsed-Field Gel Electrophoresis Analysis

Erythromycin resistance among Streptococcus pyogenes strains has been reported in Italy at high rates during the last few years. A total of 152 erythromycin-resistant isolates of this species from southern Italian regions were characterized for the macrolide-resistance phenotype and screened by PCR for the corresponding genetic determinant. A close correlation was found between these phenotypic/genotypic data concerning macrolide resistance and results of Sma I macrorestriction fragment patterns (PFGE) analysis. In fact, the vast majority of the isolates assigned to individual PFGE classes mostly belonged to a single phenotype of macrolide resistance. All untypeable isolates belonged to the M phenotype. Twenty-two distinct PFGE types were recognized, of which 11 were recorded in only one isolate (one-strain type); about 50% of typeable isolates fell into five type clusters and 70% in seven. The increased erythromycin resistance among Italian isolates of S. pyogenes does not appear to be due to the spread of a single clone, but results indicate that the majority of group A streptococci examined are probably spread from a limited number of clones

Two-year surveillance of emm-types and macrolide resistance of paediatric group A streptococcal pharyngitis isolates in the central part of Italy

Objectives. Surveillance of antimicrobial resistance and global dissemination of clones with specific emm-types is an important issue in GAS epidemiology, especially in relation to the design of a vaccine against the M protein. Methods. 584 GAS isolates were collected in central Italy during winter-spring 2012 and 2013, mainly from pharyngotonsillitis. We determined their emm-type according to CDC. Benzylpenicillin, erythromycin, telithromycin, clindamycin, tetracycline, linezolid, rifampicin, quinupristin/dalfopristin, and levofloxacin susceptibilities were tested by disc diffusion following the EUCAST guidelines. Results. 25 emm-types were recorded, nine of which accounted for almost 75% of the isolates (emm12, 89, 1, 4, 6, 3, 44, 5, 29). The overall distribution of emm-types between 2012 and 2013 was significantly different (C2-test P < 0.001) with major contributions given by emm-types 1, 3, and 89 (Fisher’s exact test P < 0.05). Resistance towards erythromycin, clindamycin, and tetracycline was observed in 8%, 4.8%, and 4.6% of cases, respectively. Macrolide resistance was mainly associated with emm-types 2, 4, 11, and 12. An important decrease in prevalence of macrolide resistance from 9.6% to 6% was recorded between 2012 and 2013. Conclusion. In view of the overall emm-distribution, the 26-valent vaccine would have covered 75% of the emm-types, while the 30-valent form would have approached 98% of coverage. Despite the slight decrease in macrolide consumption registered in the last ten years in Italy, the prevalence of macrolide resistance lowered consistently from 25-30% to less than 10%. The lower prevalence of some emmtypes or a decrease in the level of association of erythromycin resistance with some emm-types, may have well contributed to the overall drop in the observed prevalence of erythromycin resistance

Characterization of secondary metabolites, biological activity and glandular trichomes of Stachys tymphaea Hausskn. from the Monti Sibillini National Park (Central Apennines, Italy)

Stachys tymphaea (Lamiaceae) is a perennial herb growing in forest openings and dry meadows of central and southern Italy. It was investigated for the first time here, determining the content of secondary metabolites, the micromorphology of glandular trichomes, the histochemical localization of secretion, and the biological activity of the volatile oil, namely, the cytotoxic, antioxidant, and antimicrobial properties. The plant showed a peculiar molecular pattern, being rich of biophenolic compounds as flavonoids, phenylethanoid glycosides, and caffeoylquinic acid derivatives, but poor of iridoids, which are known as marker compounds of the genus Stachys. The essential oil was characterized by GC-FID and GC/MS analyses, revealing a high percentage of sesquiterpene hydrocarbons (54.6%), with germacrene D (30.0%) and (E)-b-farnesene (12.4%) as the most abundant compounds, while other main components were representatives of the diterpenes (19.2%), represented mainly by (E)-phytol (11.9%). This composition supported the taxonomic relationships in the genus Stachys, which comprises oil-poor species producing essential oils rich in hydrocarbons, with germacrene D as one of the predominant components. The micromorphological study revealed three types of glandular hairs, i.e., Type A peltate trichomes, being the primary sites of essential oil biosynthesis, Type B short-stalked trichomes, typical mucopolysaccharide producers, and Type C long capitate trichomes, secreting a complex mixture of both lipophilic and hydrophilic substances, with a major phenolic fraction. Moreover, the MTT assay revealed the potential of the volatile oil to inhibit A375, HCT116, and MDA-MB 231 tumor cells lines (IC50 values of 23.9-34.4 mg/ml)