Antibacterial and antioxidant activities of the essential oil of Artemisia echegarayi Hieron. (Asteraceae). (65/184)

Artemisia echegarayi Hieron. (Asteraceae) is commonly known in Argentina as "ajenjo". Many studies report high efficacy of essential oils against food-borne pathogenic bacteria. The antimicrobial activity and minimal inhibitory concentration of A. echegarayi essential oil were evaluated against seven bacterial species of significant importance in food hygiene, by using the disc diffusion assay and the micro-well dilution method, respectively. Volatile components of the extract were analyzed by gas chromatography-mass spectrometry and major components were determined. Furthermore, the essential oil was tested for its antioxidant activity. The essential oil inhibited the growth of gram-positive and gram-negative tested bacteria, with the exception of Proteus mirabilis. A. echegarayi essential oil presented the lowest minimal inhibitory concentration against Listeria monocytogenes and Bacillus cereus. Two terpenes, thujone and camphor, were identified from this essential oil as the principal constituents responsible for antibacterial activity. The oil showed a free radical scavenging activity equivalent to 50% of the reference compound. These preliminary studies showed promising results since this essential oil may provide an alternative to promote its use as a natural food additive.  (+info)

Concentration of hydrogen ions in several calcium hydroxide pastes over different periods of time. (66/184)


Formulation and optimization of orodispersible tablets of diazepam. (67/184)


Antibacterial activity and the variation of Tanacetum parthenium (L.) Schultz Bip. essential oils from Turkey. (68/184)

Water-distilled essential oils from herbal parts of Tanacetum parthenium from two different localities in Turkey were analyzed by GC and GC/MS. The essential oil of T. parthenium collected from Davutpasa-Istanbul location were characterized with camphor 49%, trans-chrysanthenyl acetate 22.1% and camphene 9.4%. Second plant sample is collected from the remote east end of the country Savsat-Ardahan location. The essential oil from this location was characterized with camphor 60.8% and camphene 6.8%. Unlike the former this sample contains trans-chrysanthenyl acetate in trace amount and cis- chrysanthenyl acetate in very small amount (0.6%) which is not present in the first sample. Antibacterial activity of the oils were evaluated for five Gram (+) and five Gram (-) bacteria by using a broth microdilution assay. The highest activity was observed on Bacillus subtilis, Staphylococcus aureus and methicillin-resistant S.aureus however when compared with positive control oils showed higher MIC values. The oil of Istanbul-sample showed highest activity on B. subtilis (125 microg/mL) and methicillin-resistant S. aureus (125 microg/mL) which is two fold concentration when compared with the positive control chloramphenicol (62.5 microg/mL). The oil of Ardahan sample showed the highest activity on S. aureus (125 microg/mL) which is likewise two fold concentration of the positive control chloramphenicol (62.5 microg/mL). DPPH scavenging activity was 59.3% of the oil from Davutpasa at 15 mg/mL concentration. When compared to positive control alpha-tocopherol (94.6%) Savsat oil (28.2%) showed low and Davutpasa oil showed medium DPPH scavenging activity. All of the oils showed toxicity to Vibrio fischeri in the TLC-bioluminescence assay.  (+info)

Pharmacokinetic differences in exposure to camphor after intraruminal dosing in selectively bred lines of goats. (69/184)


Coronal leakage of four intracanal medications after exposure to human saliva in the presence of a temporary filling material. (70/184)

AIM: To determine the time required for the recontamination of root canals medicated with four different materials. MATERIALS AND METHODS: A total of 60 intact, caries-free, human single-rooted teeth with straight roots were selected for this study. After chemo-mechanical preparation they must be changed in the specimens into seven groups: 10 teeth medicated with calcium hydroxide (Ca(OH) 2) + Camphorated paramonochlorophanol (CPMC) (G.1); 10 medicated with 2.5% Sodium hypochlorite (NaOCL) (G.2); 10 medicated with 2% Chlorhexidine gluconate (CHX) in gel (G.3); 10 medicated with 2% CHX in gel + Ca(OH) 2 (G.4); 10 without intracanal medicament and sealed with a coronal temporary filling (G.5). Five teeth were without intracanal medicament and coronally unsealed, used as the positive control group (PC) (G.6) and 5 teeth with intact crowns used as the negative control group (NC) (G.7). Glass vials with rubber stoppers were adjusted for use. The medicaments were prepared and injected into the root canals using sterile plastic syringes. An apparatus was used to evaluate for 30 days leakage. The chamber was filled with 3 ml of human saliva and Brain Heart Infusion (BHI) broth, incubated at 37 degrees C and checked daily for the appearance of turbidity in the BHI broth. RESULTS: Recontamination was detected after an average time of 2.6 days in group 2, 15.9 days in group 3, 30 days in group 1, 27.6 days in group 4, 2.9 days in group 5, 1 day in the positive control, and there was no contamination in the negative control group. CONCLUSION: The NaOCl group showed the highest worst average of recontamination; on the other hand, high averages were also shown by Ca(OH) 2 + CPMC and Ca(OH) 2 + 2% CHX in gel.  (+info)

Histopathological evaluation of root canal filling materials for primary teeth. (71/184)


Antimicrobial activity and essential oil composition of a new T. argyrophyllum (C. Koch) Tvzel var. argyrophyllum chemotype. (72/184)

Water-distilled essential oils from flowers and stems of Tanacetum argyrophyllum var. argyrophyllum from Turkey were analyzed by GC and GC/MS. The flower oil of T. argyrophyllum var. argyrophyllum was characterized with camphor 29.7%, borneol 12.0%, 1,8-cineole 8.4% and bornyl acetate 6.1%. Stem oil was characterized with camphor 26.6%, 1,8-cineole 17.5%, and borneol 15.0%. Our previous research and literature on the essential oil of this plant reported oils with high thujone content unlike the present study. Antibacterial activity of the oils were evaluated for five Gram-positive and five Gram-negative bacteria by using a broth microdilution assay. The highest inhibitory activity was observed against Bacillus cereus for stem oil (125 microg/mL) when compared with positive control chloramphenicol it showed the same inhibition potency. However, the same oil showed lower inhibitory activity against B. subtilis. The flower oil did not show significant activity against the tested microorganisms. DPPH radical scavenging activity of the T. argyrophyllum var. argyrophyllum oil was investigated at 15 and 10 mg/mL concentrations. However, the oils did not show any significant activity when compared to positive control alpha-tocopherol. Both of the oils showed toxicity to Vibrio fischeri in the TLC-bioluminescence assay.  (+info)