Chemical Composition, Antioxidant, DNA Damage Protective, Cytotoxic and Antibacterial Activities of Cyperus rotundus Rhizomes Essential Oil against Foodborne Pathogens.

Cyperus rotundus L. (Cyperaceae) is a medicinal herb traditionally used to treat various clinical conditions at home. In this study, chemical composition of Cyperus rotundus rhizomes essential oil, and in vitro antioxidant, DNA damage protective and cytotoxic activities as well as antibacterial activity against foodborne pathogens were investigated. Results showed that α-cyperone (38.46%), cyperene (12.84%) and α-selinene (11.66%) were the major components of the essential oil. The essential oil had an excellent antioxidant activity, the protective effect against DNA damage, and cytotoxic effects on the human neuroblastoma SH-SY5Y cell, as well as antibacterial activity against several foodborne pathogens. These biological activities were dose-dependent, increasing with higher dosage in a certain concentration range. The antibacterial effects of essential oil were greater against Gram-positive bacteria as compared to Gram-negative bacteria, and the antibacterial effects were significantly influenced by incubation time and concentration. These results may provide biological evidence for the practical application of the C. rotundus rhizomes essential oil in food and pharmaceutical industries.

Chemical Composition, Antibacterial Properties and Mechanism of Action of Essential Oil from Clove Buds against Staphylococcus aureus.

The essential oil of clove has a wide range of pharmacological and biological activities and is widely used in the medicine, fragrance and flavoring industries. In this work, 22 components of the essential oil obtained from clove buds were identified. Eugenol was the major component (76.23%). The essential oil exhibited strong antibacterial activity against Staphylococcus aureus ATCC 25923 with a minimum inhibitory concentration (MIC) of 0.625 mg/mL, and the antibacterial effects depended on its concentration and action time. Kill-time assays also confirmed the essential oil had a significant effect on the growth rate of surviving S. aureus. We hypothesized that the essential oil may interact with the cell wall and membrane first. On the one hand it destroys cell wall and membranes, next causing the losses of vital intracellular materials, which finally result in the bacterial death. Besides, essential oil penetrates to the cytoplasmic membrane or enters inside the cell after destruction of cell structure, and then inhibits the normal synthesis of DNA and proteins that are required for bacterial growth. These results suggested that the effects of the clove essential oil on the growth inhibition of S. aureus may be at the molecular level rather than only physical damage.

Resveratrol ameliorates experimental periodontitis in diabetic mice through negative regulation of TLR4 signaling.

AIM: To investigate the therapeutic effects of resveratrol (RSV) on periodontitis in diabetic mice and to explore the underlying mechanisms in vitro. METHODS: Experimental periodontitis was induced in db/db mice by ligature application of porphyromonas gingivalis. The mice were treated with RSV (20 mg/kg, p.o.) daily for 4 weeks. Alveolar bone loss, proinflammatory cytokines and TLR4 expression in the gingival tissue were measured. Cultured gingival epithelial cells (GECs) were used for in vitro studies. The transcriptional activity of TLR4 downstream signaling was analyzed using Western blotting. RESULTS: RSV administration significantly decreased the blood glucose levels, and ameliorated alveolar bone loss in db/db mice with experimental periodontitis. RSV administration also suppressed the high levels of IL-1ß, IL-6, IL-8, TNF-α, and TLR4 in gingival tissue of the mice. In the GECs incubated in high glucose medium, TLR4 expression was substantially upregulated, which was partly blocked in the presence of RSV. Lipopolysaccharides markedly increased the expression and secretion of IL-1ß, IL-6, IL-8, and TNF-α in the GECs cultured in high glucose medium, which was also partly blocked in the presence of RSV. Furthermore, RSV significantly suppressed the phosphorylation of TLR4 downstream factors NF-κB p65, p38MAPK, and STAT3. CONCLUSION: RSV exerts protective effects against experimental periodontitis in db/db mice via negative regulation of TLR4 signaling.

Urinary levels of nickel and chromium associated with dental restoration by nickel-chromium based alloys.

This paper aims to investigate if the dental restoration of nickel-chromium based alloy (Ni-Cr) leads to the enhanced excretions of Ni and Cr in urine. Seven hundred and ninety-five patients in a dental hospital had single or multiple Ni-Cr alloy restoration recently and 198 controls were recruited to collect information on dental restoration by questionnaire and clinical examination. Urinary concentrations of Ni and Cr from each subject were measure by graphite furnace atomic absorption spectrometry. Compared to the control group, the urinary level of Ni was significantly higher in the patient group of <1 month of the restoration duration, among which higher Ni excretions were found in those with either a higher number of teeth replaced by dental alloys or a higher index of metal crown not covered with the porcelain. Urinary levels of Cr were significantly higher in the three patient groups of <1, 1 to <3 and 3 to <6 months, especially in those with a higher metal crown exposure index. Linear curve estimations showed better relationships between urinary Ni and Cr in patients within 6-month groups. Our data suggested significant increased excretions of urinary Ni and Cr after dental restoration. Potential short- and long-term effects of Ni-Cr alloy restoration need to be investigated.

[Analysis of the association between renal function parameters and urinary nickel or chromium in patients with dental restoration of nickel-chromium alloys].

PURPOSE: To explore whether the renal function parameters were associated with urinary nickel(Ni) and chromium(Cr) in patients undergoing dental restoration of nickel-chromium(Ni-Cr). METHODS: Seven hundred and ninety-five Ni-Cr alloy consumers were investigated by the questionnaire and the biological examination of renal function. The correlations between renal function parameters and urinary Ni(or Cr) were determined by Student's t test, one-way ANOVA, and Logistic regression analysis using SPSS12.0 software package. RESULTS: After dividing all subjects into three groups with equal sample size by urinary Ni (<38,38-90, ≥ 90µg/mol crea.), the middle group (38-90µg/mol crea.) had a significantly higher serum creatinine and estimated glomerular filtration rate (eGFR) compared to the other two groups, and there was no significant difference in other serum or urinary parameters of renal function. After dividing all subjects into three groups by urinary Cr(<38,38-88, and ≥ 90µg/mol crea.), no change was found in serum parameters, but urinary N-acetyl-ß-D-glucosaminidase (UNAG) and retinol-binding protein (URBP) showed negative association with urinary Cr. The prevalence of either abnormal eGFR and abnormal urine parameters of renal function did not show significant change between different dose of urinary Ni or Cr. CONCLUSIONS: No association of renal changes with urinary excretion of Ni and Cr was found in patients undergoing dental restoration of Ni-Cr alloy.

[A cross-sectional survey on immunological function after dental restoration of nickel-chromium alloy].

OBJECTIVE: To investigate the immunological function parameters in patients undergoing dental restoration of nickel-chromium (Ni-Cr). METHODS: Seven hundred and ninety-five Ni-Cr alloy consumers as exposure group, together with 198 controls, were surveyed by the questionnaire and the biological examination of immunological function. RESULTS: After splitting all subjects into three groups of equal sample size by urinary Ni or urinary Cr, serum interleukin-1beta(IL-1ß) was found to be significantly higher in the group of urinary Ni > 115.73 µg/mol creatinine comparing to the group of urinary Ni < 37.28 µg/mol creatinine (P < 0.05). No changes of immunological parameters in surm [tumor necrosis factor-alpha (TNF-α), IL-1ß, and IL-6] were found in other groups of urinary Ni or Cr. Both one way analysis of variance (ANOVA) and linear regression analysis did not find any association between serum changes of immunological parameters and the parameters of alloy restoration (period, number and the level of metal crown uncovered with porcelain). CONCLUSIONS: This study did not show positive associations between dental restoration of Ni-Cr alloy and serum levels of TNF-α, IL-1ß and IL-6.

[A 3-year retrospective assessment of deciduous teeth caries in 372 children aged 3 year-old in Shanghai].

PURPOSE: To observe the 3 years changes of deciduous teeth caries in 372 children aged 3 years old in Shanghai. METHODS: 372 samples of 3 year-old children from kindergartens in Shanghai were selected for clinical examination.The prevalence of dental caries,mean dmft score, caries severity index(CSI) and caries filling rate were calculated. The results were analyzed with SPSS13.0 software package for Chi(2) test, ANOVA and SNK. RESULTS: It was found that from 2005 to 2007,the prevalence of dental caries was 40.90%, 50.80% and 62.40%, respectively. The mean dmft was 2.17+/-3.38+/-2.56+/-3.61 and 3.15+/-3.87, respectively. The CSI was 6.38+/-11.16+/-7.67+/-12.04 and 8.73+/-13.03, respectively. The caries filling rate was 5.35%,13.46% and 18.15%,respectively. The prevalence of dental caries, mean dmft, CSI and caries filling rate increased gradually as the children grew up. There was significant difference among 3 years (Chi(2)=16.423,P<0.01;F=8.185,P<0.01;F=3.509,P<0.05;Chi(2)=16.423,P<0.05). SNK analysis showed that there was significant difference of dmft between 2005 and 2006 ,2005 and 2007 was found. Significant difference of CSI only between 2005 and 2007. No significant difference of incidence of caries between 2006 and 2007 was found. There was no significant difference between male and female in prevalence of dental caries,mean dmft,CSI and caries filling rate (P>0.05). CONCLUSION: The trend that the status of dental caries rapidly increases as the children grow up is decreasing in Shanghai;the filling rate is still very low, early prevention and treatment for deciduous caries are needed. Supported by Shanghai Municipal Health Bureau for Development of Science and Technology (Grant No.044034).