The in vitro inhibitory activity of crude EtOH/H2O extracts from the leaves and stems of Rosmarinus officinalis L. was evaluated against the following microorganisms responsible for initiating dental caries: Streptococcus mutans, S. salivarius, S. sobrinus, S. mitis, S. sanguinis, and Enterococcus faecalis. Minimum inhibitory concentrations (MIC) were determined with the broth microdilution method. The bioassay-guided fractionation of the leaf extract, which displayed the higher antibacterial activity than the stem extract, led to the identification of carnosic acid (2) and carnosol (3) as the major compounds in the fraction displaying the highest activity, as identified by HPLC analysis. Rosmarinic acid (1), detected in another fraction, did not display any activity against the selected microorganisms. HPLC Analysis revealed the presence of low amounts of ursolic acid (4) and oleanolic acid (5) in the obtained fractions. The results suggest that the antimicrobial activity of the extract from the leaves of R. officinalis may be ascribed mainly to the action of 2 and 3.

Candidiasis therapy, especially for candidiasis caused by Candida non-albicans species, is limited by the relatively reduced number of antifungal drugs and the emergence of antifungal tolerance. This study evaluates the anticandidal activity of 41 plant-derived products against Candida species, in both planktonic and biofilm cells. This study also evaluates the toxicity and the therapeutic action of the most active compounds by using the Caenorhabditis elegans–Candida model. The planktonic cells were cultured with various concentrations of the tested agents. The Cupressus sempervirens, Citrus limon, and Litsea cubeba essential oils as well as gallic acid were the most active anticandidal compounds. Candida cell re-growth after treatment with these agents for 48 h demonstrated that the L. cubeba essential oil and gallic acid displayed fungistatic activity, whereas the C. limon and C. sempervirens essential oils exhibited fungicidal activity. The C. sempervirens essential oil was not toxic and increased the survival of C. elegans worms infected with C. glabrata or C. orthopsilosis. All the plant-derived products assayed at 250 µg/mL affected C. krusei biofilms. The tested plant-derived products proved to be potential therapeutic agents against Candida, especially Candida non-albicans species, and should be considered when developing new anticandidal agents.

The essential oil of Rosmarinus offi cinalis L. (rosemary) was obtained by hydro-distillation and analysed by gas chromatography-mass spectrometry. Sixty-two constituents were identifi ed, representing 98.06% of the total oil content. Oxygenated monoterpenes were the predominant components. The rosemary oil was characterized as having prominent (> 5%) contents of camphor (18.9%), verbenone (11.3%), α-pinene (9.6%), β-myrcene (8.6%), 1,8-cineole (8.0%), and β-caryophyllene (5.1%). The antimicrobial activity of the oil as well as of its major constituents was tested against the following microorganisms: Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis, which are potentially responsible for the formation of dental caries in humans. The microdilution method was used for determination of the minimum inhibitory concentration (MIC) during evaluation of the antibacterial activity. The essential oil displayed low activity against the selected microorganisms. In the present study, the pure major compounds were more active than the essential oil. Among all the microorganisms tested, the pathogen S. mitis was the most susceptible and E. faecalis was the most resistant to the evaluated samples. This is the fi rst report on antimicrobial activity of the major components of rosemary oil against oral pathogens.

The present article describes an l-amino acid oxidase from Bothrops atrox snake venom as with antiprotozoal activities in Trypanosoma cruzi and in different species of Leishmania (Leishmania braziliensis, Leishmania donovani and Leishmania major). Leishmanicidal effects were inhibited by catalase, suggesting that they are mediated by H(2)O(2) production. Leishmania spp. cause a spectrum of diseases, ranging from self-healing ulcers to disseminated and often fatal infections, depending on the species involved and the host's immune response. BatroxLAAO also displays bactericidal activity against both Gram-positive and Gram-negative bacteria. The apoptosis induced by BatroxLAAO on HL-60 cell lines and PBMC cells was determined by morphological cell evaluation using a mix of fluorescent dyes. As revealed by flow cytometry analysis, suppression of cell proliferation with BatroxLAAO was accompanied by the significant accumulation of cells in the G0/G1 phase boundary in HL-60 cells. BatroxLAAO at 25 μg/mL and 50 μg/mL blocked G0-G1 transition, resulting in G0/G1 phase cell cycle arrest, thereby delaying the progression of cells through S and G2/M phase in HL-60 cells. This was shown by an accentuated decrease in the proportion of cells in S phase, and the almost absence of G2/M phase cell population. BatroxLAAO is an interesting enzyme that provides a better understanding of the ophidian envenomation mechanism, and has biotechnological potential as a model for therapeutic agents.

The results suggest that the analgesic effects of the acetyl derivative of RA operate via a peripheral-mediated mechanism. The acetyl ester derivative of RA is potentially applicable as a new lead compound for the management of pain and inflammation.

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This work investigated the antibacterial activity of 15 commercially available plant-derived essential oils (EOs) against a panel of oral pathogens. The broth microdilution method afforded the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the assayed EOs. The EO obtained from Cinnamomum zeylanicum (Lauraceae) (CZ-EO) displayed moderate activity against Fusobacterium nucleatum (MIC and MBC = 125 μg/mL), Actinomyces naeslundii (MIC and MBC = 125 μg/mL), Prevotella nigrescens (MIC and MBC = 125 μg/mL) and Streptococcus mutans (MIC = 200 μg/mL; MBC = 400 μg/mL). (Z)-isosafrole (85.3%) was the main chemical component of this oil. We did not detect cinnamaldehyde, previously described as the major constituent of CZ-EO, in specimens collected in other countries.

The activity of usnic acid against Candida orthopsilosis and Candida parapsilosis on planktonic and biofilm conditions was investigated by using a broth microdilution and microplate methods. Potent in vitro activities against different Candida species were obtained. The metabolic activity of sessile cells of C. parapsilosis complex was reduced by 80% at four times the 80% inhibitory concentration. The in vitro studies support further efforts to determine whether usnic acid can be used clinically to cure patients with Candida infections.A mong the Candida strains reported to cause human diseases, more than 17 different species have been identified (9,19). Many of these species have been observed to occur in the hemodialysis setting and/or to exhibit innate or acquired resistance to one or more established antifungal agents (4,12,13,16,21). In addition, the use of molecular identification methods has resulted in the identification of new species within larger species complex such as Candida orthopsilosis and Candida metapsilosis within the Candida parapsilosis complex (23). In particular, the percentage of isolates of C. orthopsilosis has been much higher in the C. parapsilosis complex isolates in Latin America (12.7%) (11).The small number of drugs available for fungal treatment encourages the search for new chemotherapeutic agents. Usnic acid (2,6-diacetyl-1,2,3,9b-tetrahydro-7,9-dihydroxy-8,9b-dimethyldibenzofuran-1,3-dione), a secondary lichen metabolite, is known to possesses antimicrobial properties in addition to antiviral, antiprotozoal, antiproliferative, anti-inflammatory, and analgesic activity (10).With respect to antimicrobial properties, usnic acid has activity against a number of planktonic Gram-positive bacteria and also has the capacity to control biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa (8). Indeed, the mechanism of action expressed by usnic acid is still unknown. According to the same study (8), usnic acid could inhibit quorum sensing in P. aeruginosa biofilms.Usnic acid has been tested against some Candida species, but there is no published data concerning its activity against the newly described species within the C. parapsilosis complex. Thus, we tested usnic acid in both planktonic or biofilm modes of growth in C. orthopsilosis and C. parapsilosis.Six isolates of C. parapsilosis complex able to form biofilms were collected from a hemodialysis unit located in the state of São Paulo, Brazil, between March 2006 and March 2007 obtained from 110 samples of water that were selected for testing. The identification of C. parapsilosis and C. orthopsilosis was confirmed by molecular methods as described previously (23). The MIC for usnic acid of planktonic C. parapsilosis complex cultures was determined in RPMI 1640 buffered with morpholinepropanesulfonic acid (MOPS) (both from Sigma Chemical Co., St. Louis, MO) using a broth microdilution method adapted from the CLSI approved standard (M27-A3) (6). Briefly, the usnic acid (Sigma) was dissolved in 5% (vol/vol) in dimethyl ...