Intracanal Microbiological Contamination Reduction Using Low-intensity Laser Associated with a Photosensitizer - In Vivo Study in Teeth of Dogs.

This study evaluated the efficacy of photodynamic therapy using the photosensitizer azulene and low-intensity laser associated with standard root chemical-surgical preparation (performed with 0.5% sodium hypochlorite) in dogs. Twenty animals from the Veterinary Hospital of the School of Veterinary Medicine and Animal Science, University of São Paulo (HOVET-FMVZ/USP) and treated at the Compared Dentistry Laboratory (Laboratório de Odontologia Veterinária [LOC]-FMVZ/USP) were included. Each subject possessed one single rooted tooth with complete root formation, pulp necrosis, complicated crown fracture and periapical bone rarefaction at the time of the radiographic examination. The endodontic treatment was performed in all dogs, which were divided into two equal groups. For group one, the standard chemical-surgical preparation was followed by the photodynamic therapy to evaluate the role of azulene after instrumentation. For group two, the photodynamic therapy was followed by the standard chemical-surgical preparation to evaluate the antimicrobial action of azulene before instrumentation. The results show that intracanal photodynamic therapy is efficient in eliminating unspecified bacterial and Enterococcus organism loads. In addition, this therapeutic modality reduces yeast contamination. The photodynamic therapy showed similar efficacy compared to standard chemical-surgical preparation. The application order of therapeutic modalities does not influence intracanal disinfection in both cases. This study shows that photodynamic therapy with low-intensity laser and azulene as a photosensitizer is a feasible alternative for improving treatment outcomes in routine practice of veterinary dentistry.

Antibacterial and antiproliferative activities of the fresh leaf essential oil of Psidium guajava L. (Myrtaceae) / Atividades antibacteriana e antiproliferativa do óleo essencial das folhas frescas de Psidium guajava L. (Myrtaceae)

Abstract This study evaluated the antibacterial and antiproliferative activities of the essential oil of Psidium guajava leaves (PG-EO), traditionally used in folk medicine. The essential oil was obtained from fresh leaves by hydrodistillation, using a modified Clevenger apparatus. The major PG-EO chemical constituents were identified by GC-MS and GC-FID as being β-caryophyllene (16.1%), α-humulene (11.9%), aromadendrene oxide (14.7%), δ-selinene (13.6%), and selin-11-en-4α-ol (12.5%). The antibacterial activity of the essential oil of P. guajava leaves was determined in terms of its minimum inhibitory concentrations (MIC) using the broth microdilution method in 96-well microplates. PG-EO had moderate activity against Streptococcus mutans (MIC = 200 µg/mL), S. mitis (MIC = 200 µg/mL), S. sanguinis (MIC = 400 µg/mL), S. sobrinus (MIC = 100 µg/mL), and S. salivarius (MIC = 200 µg/mL). The antiproliferative activity was evaluated against different tumor cell lines: breast adenocarcinoma (MCF-7), human cervical adenocarcinoma (HeLa), and human gliobastoma (M059J). A normal human cell line (GM07492A, lung fibroblasts) was included. The antiproliferative activity was evaluated using the XTT assay and the results were expressed as IC50. The essential oil showed significantly lower IC50 values against MCF-7 and M059J lines than that obtained for the normal line, showing selectivity. Our results suggest that the essential oil of Psidium guajava L. has promising biological activities and can be considered a new source of bioactive compounds.

Resumo Este estudo avaliou as atividades antibacteriana e antiproliferativa do óleo essencial das folhas frescas de Psidium guajava (PG-OE), tradicionalmente utilizadas na medicina popular. O óleo essencial foi obtido por hidrodestilação das folhas frescas, utilizando aparelho do tipo Clevenger. Os principais constituintes químicos de PG-OE identificados por CG-EM e CG-DIC foram: β-cariofileno (16,1%), α-humuleno (11,9%), óxido de aromadendreno (14,7%), δ-selineno (13,6%) e selin-11-en-4α-ol (12,5%). A atividade antibacteriana do óleo essencial das folhas de P. guajava foi determinada em termo de sua concentração inibitória mínima (CIM) utilizando o método de microdiluição de caldo em microplacas de 96 poços. PG-OE apresentou moderada atividade contra Streptococcus mutans (CIM = 200 μg/mL), S. mitis (CIM = 200 μg/mL), S. sanguinis (CIM = 400 μg/mL), S. sobrinus (CIM = 100 μg/mL) e S. salivarius (CIM = 200 μg/mL). A atividade antiproliferativa foi avaliada frente a diferentes linhagens de células tumorais como: adenocarcinoma de mama (MCF-7), adenocarcinoma cervical humano (HeLa) e gliobastoma humano (M059J). Foi incluída uma linhagem celular humana normal (GM07492A, fibroblastos pulmonares). A atividade antiproliferativa foi avaliada utilizando o ensaio XTT e os resultados foram expressos como CI50. As linhagens MCF-7 e M059J mostraram valores significativamente mais baixos de CI50 do que os obtidos para a linhagem normal, mostrando seletividade. Nossos resultados sugerem que o óleo essencial das folhas frescas de Psidium guajava L. possui atividades biológicas promissoras e pode ser considerado como uma nova fonte de compostos bioativos.

Chemical characterization and bioherbicidal potential of the essential oil from the leaves of Unonopsis guatterioides (A.DC.) R.E.Fr. (Annonaceae).

The chemical composition and the phytotoxicity potential of the essential oil from leaves of Unonopsis guatterioides (A.DC.) R.E.Fr. (Annonaceae) was investigated. Gas chromatography/mass spectrometry analyses revealed 16 constituents representing 99.50% of the total essential oil, composed mainly of sesquiterpenes. α-copaene, bicyclogermacrene and trans-caryophyllene were the major components (15.7% each), followed by α-humullene, allo-aromadendrene and (+)-spathulenol (9.0, 8.4 and 7.3%, respectively). The essential oil inhibited seed germination and growth in both monocotyledon (Allium cepa) and dicotyledon (Lactuca sativa) models, pointing to a promising application of this oil obtained from the leaves of U. guatterioides as a new bioherbicide.

Antibacterial and antiproliferative activities of the fresh leaf essential oil of Psidium guajava L. (Myrtaceae).

This study evaluated the antibacterial and antiproliferative activities of the essential oil of Psidium guajava leaves (PG-EO), traditionally used in folk medicine. The essential oil was obtained from fresh leaves by hydrodistillation, using a modified Clevenger apparatus. The major PG-EO chemical constituents were identified by GC-MS and GC-FID as being ß-caryophyllene (16.1%), α-humulene (11.9%), aromadendrene oxide (14.7%), δ-selinene (13.6%), and selin-11-en-4α-ol (12.5%). The antibacterial activity of the essential oil of P. guajava leaves was determined in terms of its minimum inhibitory concentrations (MIC) using the broth microdilution method in 96-well microplates. PG-EO had moderate activity against Streptococcus mutans (MIC = 200 µg/mL), S. mitis (MIC = 200 µg/mL), S. sanguinis (MIC = 400 µg/mL), S. sobrinus (MIC = 100 µg/mL), and S. salivarius (MIC = 200 µg/mL). The antiproliferative activity was evaluated against different tumor cell lines: breast adenocarcinoma (MCF-7), human cervical adenocarcinoma (HeLa), and human gliobastoma (M059J). A normal human cell line (GM07492A, lung fibroblasts) was included. The antiproliferative activity was evaluated using the XTT assay and the results were expressed as IC50. The essential oil showed significantly lower IC50 values against MCF-7 and M059J lines than that obtained for the normal line, showing selectivity. Our results suggest that the essential oil of Psidium guajava L. has promising biological activities and can be considered a new source of bioactive compounds.

Chemical composition and evaluation of antinociceptive activity of the essential oil of Stevia serrata Cav. from Guatemala.

The composition and the antinociceptive activity of the essential oil of Stevia serrata Cav. from a population located in the west highlands of Guatemala were evaluated. A yield of 0.2% (w/w) of essential oil was obtained by hydrodistillation of the dried aerial parts of the plant. The essential oil analysed by GC-FID and GC-MS showed a high content of sesquiterpenoids, with chamazulene (60.1%) as the major component and 91.5% of the essential oil composition was identified. To evaluate antinociceptive activity in mice, the essential oil of S. serrata Cav. was administered as gavage, using three different doses. In the formalin test, the animals were pre-treated with oral doses of the essential oil before the administration of formalin. Oral administration of S. serrata Cav. essential oil produced a marked antinociceptive activity. Therefore, the plant could be domesticated as a source of essential oil rich in chamazulene for developing medicinal products.

Isolation and Antifouling Activity of Azulene Derivatives from the Antarctic Gorgonian Acanthogorgia laxa.

Three azulenoid sesquiterpenes (1 - 3) were isolated from the Antarctic gorgonian Acanthogorgia laxa collected by bottom trawls at -343 m. Besides linderazulene (1), and the known ketolactone 2, a new brominated C16 linderazulene derivative (3) was also identified. This compound has an extra carbon atom at C(7) of the linderazulene framework. The antifouling activity of compounds 1 and 2 was assayed in the laboratory with Artemia salina larvae, and also in field tests, by incorporation in soluble-matrix experimental antifouling paints. The results obtained after a 45 days field trial of the paints, showed that compounds 1 and 2 displayed good antifouling potencies against a wide array of organisms. Compound 3, a benzylic bromide, was unstable and for this reason was not submitted to bioassays. Two known cembranolides: pukalide and epoxypukalide, were also identified as minor components of the extract.

Physicochemical and antioxidant characterization of Justicia spicigera.

Extracts with water:ethanol (100:0, 70:30, 50:50, 30:70, 0:100) solutions from fresh (F), just dried (JD), dried and stored for one year (DS) Justicia spicigera leaves were obtained using the stirring and ultrasound techniques. Extracts were analyzed in physicochemical and antioxidant characteristics. Identification of chemical compounds by gas chromatography-mass spectroscopy (GC-MS) was also performed. 2.14±0.91, 5.67±1.70, and 8.52±4.97g Gallic acid equivalents/100g dry weight (d.w.) of phenolic compounds were found, in average, for F, JD, and DS J. spicigera, respectively. 2.22±1.31, 2.58±2.11, and 8.48±3.78g Trolox equivalents/100g d.w. were detected with the ABTS method and 0.49±0.33, 1.23±0.87, and 0.88±0.94g with the DPPH method for F, JD and DS J. spicigera, respectively. Eucalyptol, phytol, and azulene were identified as the main compounds. J. spicigera showed colors (green-iridescent, green-yellow, or pink of different intensities) and antioxidant characteristics depending on the solvent concentration. Extracts could be used in the food and pharmaceutical industries.

Chemical composition and antimicrobial activity of the essential oils of Onychopetalum amazonicum R.E.Fr.

The essential oils from leaves, twigs and trunk bark of Onychopetalum amazonicum R.E. Fr. (Annonaceae), obtained by hydrodistillation, were analysed by GC and GC-MS, and also were evaluated for in vitro antimicrobial activity. Forty-one compounds, which correspond to 75.0-92.2% of the oil components, were identified. Major compounds were sesquiterpenes, including (E)-caryophyllene, caryophyllene oxide, spathulenol, α-gurjunene, allo-aromadendrene and α-epi-cadinol. The oils were evaluated for antimicrobial activities against four bacteria strains and five pathogenic fungi. The oil of the trunk bark exhibited good activity against Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 10538 and Kocuria rhizophila ATCC 9341, with a minimal inhibitory concentration of 62.5 µg/mL. The essential oil composition and the antimicrobial evaluation are reported for the first time for the genus Onychopetalum.

Oligo-carrageenan kappa-induced reducing redox status and increase in TRR/TRX activities promote activation and reprogramming of terpenoid metabolism in Eucalyptus trees.

In order to analyze whether the reducing redox status and activation of thioredoxin reductase (TRR)/thioredoxin(TRX) system induced by oligo-carrageenan (OC) kappa in Eucalyptus globulus activate secondary metabolism increasing terpenoid synthesis, trees were sprayed on the leaves with water, with OC kappa, or with inhibitors of NAD(P)H, ascorbate (ASC) and (GSH) synthesis and TRR activity, CHS-828, lycorine, buthionine sulfoximine (BSO) and auranofine, respectively, and with OC kappa and cultivated for four months. The main terpenoids in control Eucalyptus trees were eucalyptol (76%), α-pinene (7.4%), aromadendrene (3.6%), silvestrene (2.8%), sabinene (2%) and α-terpineol (0.9%). Treated trees showed a 22% increase in total essential oils as well as a decrease in eucalyptol (65%) and sabinene (0.8%) and an increase in aromadendrene (5%), silvestrene (7.8%) and other ten terpenoids. In addition, treated Eucalyptus showed seven de novo synthesized terpenoids corresponding to carene, α-terpinene, α-fenchene, γ-maaliene, spathulenol and α-camphenolic aldehyde. Most increased and de novo synthesized terpenoids have potential insecticidal and antimicrobial activities. Trees treated with CHS-828, lycorine, BSO and auranofine and with OC kappa showed an inhibition of increased and de novo synthesized terpenoids. Thus, OC kappa-induced reducing redox status and activation of TRR/TRX system enhance secondary metabolism increasing the synthesis of terpenoids and reprogramming of terpenoid metabolism in Eucalyptus trees.

Induction of defensive response in Eucalyptus globulus plants and its persistence in vegetative propagation.

The expression of defensive compounds derived from secondary metabolism in plants of Eucalyptus globulus Labill, and the persistence of these in vegetative propagation was evaluated by gas chromatography with flame ionization (GC-FID) and mass spectrometry (MS). The plants were induced by attack from the insect Ctenarytaina eucalypti ("blue gum psyllid") and by mechanical damage. Defense responses were activated in plants for the different types of tested induction. We identified four defensive compounds present in the leaves of plants induced in entomological form (beta-terpineol, aromadendrene, caryophyllene-oxide and eremophilene); all remained in the vegetative propagation. After mechanical induction, we identified three compounds (beta-terpineol, aromadendrene and ledol), of which ledol and aromadendrene persisted in the vegetative propagation. Virtually all the compounds detected, in addition to persisting in the vegetative propagation, showed specificity for the induction type, whether entomological or mechanical, except for aromadendrene, which was expressed in both types of induction.

Pelargonium graveolens L'Her. and Artemisia arborescens L. essential oils: chemical composition, antifungal activity against Rhizoctonia solani and insecticidal activity against Rhysopertha dominica.

The chemical composition of the Pelargonium graveolens essential oil allowed the identification of 15 compounds (93.86% of the total essential oil). The major fractions were citronellol (35%) and geraniol (28.8%). The chemical composition of the Artemisia arborescens essential oil revealed twenty-one compounds representing 93.57% of the total essential oil. The main compounds were chamazulene (31.9%) and camphor (25.8%). The insecticidal effects were tested towards the insect Rhysopertha dominica. Results revealed that these two essential oils were highly effective against R. dominica at the dose of 50 µL on Petri dish of 8.5 cm of diameter. The antifungal activity was evaluated against Rhizoctonia solani and results showed that both of the essential oils were highly active at a dose of 12.5 µL/20 mL of PDA. Moreover, the inhibitory effect of P. graveolens essential oil was evidenced as stronger than that of the A. arborescens oil for all the tested doses.

Cytotoxic and anti-infective sesquiterpenes present in Plagiochila disticha (Plagiochilaceae) and Ambrosia peruviana (Asteraceae).

A pharmacological screening of the ethanol extract and fractions of two Peruvian medicinal plants, Plagiochila disticha and Ambrosia peruviana, led to the isolation and characterization of three ENT-2,3-secoaromadendrane-type sesquiterpenoids, named plagiochiline A ( 1), I ( 2), and R ( 3), as well as of two pseudoguaianolids, damsin ( 4) and confertin ( 5), which exhibited significant cytotoxic activity against a panel of human tumor cell lines. Compounds 1, 4, and 5 were also investigated for their in vitro antileishmanial, trypanocidal, and antituberculosis activity against Leishmania amazonensis axenic amastigotes and Trypanosoma cruzi trypomastigotes, as well as against MDR and sensitive strains of Mycobacterium tuberculosis, respectively.

Trypanosoma cruzi: activity of essential oils from Achillea millefolium L., Syzygium aromaticum L. and Ocimum basilicum L. on epimastigotes and trypomastigotes.

Trypanocidal activity of clove (Syzygium aromaticum L.), basil (Ocimum basilicum L.) and yarrow (Achillea millefolium L.) essential oils and some of their constituents (eugenol and linalool) was investigated on Trypanosoma cruzi epimastigote and bloodstream trypomastigote forms. Steam distillation was used to isolate the essential oils, with chemical analyses performed by gas chromatography (GC) and GC coupled to mass spectrometry (GC-MS). The IC(50) (concentration that inhibits 50% parasite growth) of the oils and constituents upon T. cruzi was determined by cell counting in a Neubauer chamber. Cell morphology alterations were observed by scanning and transmission electron microscopy. Treatment with oils and constituents demonstrated that they inhibit parasite growth, with clove essential being the most effective one (IC(50)=99.5 microg/ml for epimastigotes and 57.5 microg/ml for trypomastigotes). Ultrastructural alterations were observed mainly in the nucleus.

Efficiency of NaOCl and laser-assisted photosensitization on the reduction of Enterococcus faecalis in vitro.

OBJECTIVE: To investigate the action of a red laser associated with a photosensitizer on the reduction of Enterococcus faecalis in dental root canal in vitro. STUDY DESIGN: Thirty prepared teeth with single canals were contaminated. The chemical group was irrigated with 0.5% NaOCl and left flooded for 30 minutes. In the laser group, a paste-based photosensitizer was maintained in the root canals for 5 minutes, and then irradiated with a laser at 685 nm using an optical fiber for an E of 1.8 J during 3 minutes. After treatment, the canal content was collected, serially diluted, and cultured to determine the number of colony-forming units. RESULTS: Photosensitizer alone or laser alone did not have any bactericidal effect. Chemical solution reduced viable bacteria in 93.25%. Laser photosensitization resulted in a reduction of 99.2%, a significantly higher bacterial reduction than NaOCl. CONCLUSION: Laser photosensitization was effective for reducing E. faecalis in root canals and could be an adjunct to endodontic treatment.

Comparative study between the effects of photodynamic therapy and conventional therapy on microbial reduction in ligature-induced peri-implantitis in dogs.

BACKGROUND: Progressive peri-implant bone losses, which are accompanied by inflammatory lesions in the soft tissues, are referred to as peri-implantitis. The aim of this study was to compare the effects of photodynamic therapy (PDT) and conventional technique on microbial reduction in ligature-induced peri-implantitis in dogs. METHODS: Eighteen third premolars from nine Labrador retriever dogs were extracted and the implants were submerged. After osseointegration, peri-implantitis was induced. After 4 months, ligature was removed and natural bacterial plaque was allowed to form for another 4 months. The animals were then randomly divided into two groups. In the conventional group, they were treated using mucoperiosteal flaps for scaling the implant surface and chlorexidine (conventional) irrigation. In the PDT group, only mucoperiosteal scaling was carried out before photodynamic therapy. Inside the peri-implant pocket, a paste-based azulene photosensitizer was placed and then a GaAlAs low-power laser (lambda=660 nm, P=40 mW, E=7.2 J for 3 minutes) was used. Microbiological samples were obtained before and immediately after treatment. Before treatment, one implant was removed and analyzed by scanning electron microscopy to validate the contamination. RESULTS: The results of this study showed that Prevotella sp., Fusobacterium sp., and S. Beta-haemolyticus were significantly reduced for both groups. After treatment, no significant differences were observed between the groups. CONCLUSION: These findings suggest that photodynamic therapy is a non-invasive method that could be used to reduce microorganisms in peri-implantitis.