Background Salivary nitrate is positively correlated with plasma nitrate and its level is 9 times the plasma level after nitrate loading. Nitrate in saliva is known to be reduced to nitrite by oral bacteria. Nitrate a...Background Salivary nitrate is positively correlated with plasma nitrate and its level is 9 times the plasma level after nitrate loading. Nitrate in saliva is known to be reduced to nitrite by oral bacteria. Nitrate and nitrite levels in saliva are 3-5 times those in serum in physiological conditions respectively in our previous study. The biological functions of high salivary nitrate and nitrite are still not well understood. The aim of this in vitro study was to investigate the antimicrobial effects of nitrate and nitrite on main oral pathogens under acidic conditions. Methods Six common oral pathogens including Streptococcus mutans NCTC 10449, Lactobacillus acidophilus ATCC 4646, Porphyromonas gingivalis ATCC 33277, Capnocytophaga gingivalis ATCC 33624, Fusobacterium nucleatum ATCC 10953, and Candida albicans ATCC 10231 were cultured in liquid medium. Sodium nitrate or sodium nitrite was added to the medium to final concentrations of 0, 0.5, 1, 2, and 10 mmol/L. All of the microorganisms were incubated for 24 to 48 hours. The optical densities （OD） of cell suspensions were determined and the cultures were transferred to solid nutrient broth medium to observe the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration for the six tested pathogens. Results Nitrite at concentrations of 0.5 to 10 mmol/L had an inhibitory effect on all tested organisms at low pH values. The antimicrobial effect of nitrite increased with the acidity of the medium. Streptococcus mutans NCTC 10449 was highly sensitive to nitrite at low pH values. Lactobacillus acidophilus ATCC 4646 and Candida albicans ATCC 10231 were relatively resistant to acidified nitrite. Nitrate at the given concentrations and under acidic conditions had no inhibitory effect on the growth of any of the tested pathogens. Conclusion Nitrite, at a concentration equal to that in human saliva, is both cytocidal and cytostatic to six principal oral pathogens in vitro, whereas nitrate at a similar concentration has no antimicrobial effect on these organisms.展开更多
Background:Benign prostatic hyperplasia(BPH)is the most common disease in elderly men.There is increasing evidence that periodontitis increases the risk of BPH,but the specific mechanism remains unclear.This study aim...Background:Benign prostatic hyperplasia(BPH)is the most common disease in elderly men.There is increasing evidence that periodontitis increases the risk of BPH,but the specific mechanism remains unclear.This study aimed to explore the role and mechanism of the key periodontal pathogen Porphyromonas gingivalis(P.gingivalis)in the development of BPH.Methods:The subgingival plaque(Sp)and prostatic fluid(Pf)of patients with BPH concurrent periodontitis were extracted and cultured for 16S r DNA sequencing.Ligature-induced periodontitis,testosterone-induced BPH and the composite models in rats were established.The P.gingivalis and its toxic factor P.gingivalis lipopolysaccharide(P.gLPS)were injected into the ventral lobe of prostate in rats to simulate its colonization of prostate.P.g-LPS was used to construct the prostate cell infection model for mechanism exploration.Results:P.gingivalis,Streptococcus oralis,Capnocytophaga ochracea and other oral pathogens were simultaneously detected in the Sp and Pf of patients with BPH concurrent periodontitis,and the average relative abundance of P.gingivalis was found to be the highest.P.gingivalis was detected in both Sp and Pf in 62.5%of patients.Simultaneous periodontitis and BPH synergistically aggravated prostate histological changes.P.gingivalis and P.gLPS infection could induce obvious hyperplasia of the prostate epithelium and stroma(epithelial thickness was 2.97-fold and 3.08-fold that of control group,respectively),and increase of collagen fibrosis(3.81-fold and 5.02-fold that of control group,respectively).P.gingivalis infection promoted prostate cell proliferation,inhibited apoptosis,and upregulated the expression of inflammatory cytokines interleukin-6(IL-6;4.47-fold),interleukin-6 receptor-α(IL-6Rα;5.74-fold)and glycoprotein 130(gp130;4.47-fold)in prostatic tissue.P.g-LPS could significantly inhibit cell apoptosis,promote mitosis and proliferation of cells.P.g-LPS activates the Akt pathway through IL-6/IL-6Rα/gp130 complex,which destroys the imbalance between proliferation and apoptosis of prostate cells,induces BPH.Conclusion:P.gingivalis was abundant in the Pf of patients with BPH concurrent periodontitis.P.gingivalis infection can promote BPH,which may affect the progression of BPH via inflammation and the Akt signaling pathway.展开更多
In the present study, two new limonoids, 1α, 7α-dihydroxyl-3α-acetoxyl-12α-ethoxylnimbolinin(1) and 1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12β-ethoxylnimbolinin(2), together with other four known limonoids(3-6)...In the present study, two new limonoids, 1α, 7α-dihydroxyl-3α-acetoxyl-12α-ethoxylnimbolinin(1) and 1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12β-ethoxylnimbolinin(2), together with other four known limonoids(3-6), were isolated from the fruits of Melia toosendan. Their structures were elucidated by means of extensive spectroscopic analyses(NMR and ESI-MS) and comparisons with the data reported in the literature. The isolated compounds were evaluated for their antibacterial activities. Compound 4 exhibited significant antibacterial activity against an oral pathogen, Porphyromonas gingivalis ATCC 33277, with an MIC value of 15.2 μg·m L-1. Compound 2 was also active against P. gingivalis ATCC 33277, with an MIC value of 31.25 μg·m L-1. In conlcusion, our resutls indicate that these compounds may provide a basis for future development of novel antibiotics.展开更多
基金This research was supported by grants from the National Natural Science Foundation of China (No. 30430690), and Beijing Natural Science Foundation (No. 7042025).
文摘Background Salivary nitrate is positively correlated with plasma nitrate and its level is 9 times the plasma level after nitrate loading. Nitrate in saliva is known to be reduced to nitrite by oral bacteria. Nitrate and nitrite levels in saliva are 3-5 times those in serum in physiological conditions respectively in our previous study. The biological functions of high salivary nitrate and nitrite are still not well understood. The aim of this in vitro study was to investigate the antimicrobial effects of nitrate and nitrite on main oral pathogens under acidic conditions. Methods Six common oral pathogens including Streptococcus mutans NCTC 10449, Lactobacillus acidophilus ATCC 4646, Porphyromonas gingivalis ATCC 33277, Capnocytophaga gingivalis ATCC 33624, Fusobacterium nucleatum ATCC 10953, and Candida albicans ATCC 10231 were cultured in liquid medium. Sodium nitrate or sodium nitrite was added to the medium to final concentrations of 0, 0.5, 1, 2, and 10 mmol/L. All of the microorganisms were incubated for 24 to 48 hours. The optical densities （OD） of cell suspensions were determined and the cultures were transferred to solid nutrient broth medium to observe the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration for the six tested pathogens. Results Nitrite at concentrations of 0.5 to 10 mmol/L had an inhibitory effect on all tested organisms at low pH values. The antimicrobial effect of nitrite increased with the acidity of the medium. Streptococcus mutans NCTC 10449 was highly sensitive to nitrite at low pH values. Lactobacillus acidophilus ATCC 4646 and Candida albicans ATCC 10231 were relatively resistant to acidified nitrite. Nitrate at the given concentrations and under acidic conditions had no inhibitory effect on the growth of any of the tested pathogens. Conclusion Nitrite, at a concentration equal to that in human saliva, is both cytocidal and cytostatic to six principal oral pathogens in vitro, whereas nitrate at a similar concentration has no antimicrobial effect on these organisms.
基金supported(in part)by the National Natural Science Foundation of China(82200862,82370778)the Hubei Provincial Natural Science Foundation(2022CFB681,2023AFA061,2019CFB760)+4 种基金the Hubei Province Health and Family Planning Scientific Research Project(WJ2023M058,WJ2019H035)the Key Scientific Research Project of Education Department of Henan Province(22A320038)the Fundamental Research Funds for the Central Universities(2042023kf1019,2042023kf0051,2042022kf0072)the Zhongnan Hospital of Wuhan University,Science Technology and Innovation Seed Fund(CXPY2022074)the Young Top-notch Talent Cultivation Program of Hubei Province(for Prof.Zeng XT).
文摘Background:Benign prostatic hyperplasia(BPH)is the most common disease in elderly men.There is increasing evidence that periodontitis increases the risk of BPH,but the specific mechanism remains unclear.This study aimed to explore the role and mechanism of the key periodontal pathogen Porphyromonas gingivalis(P.gingivalis)in the development of BPH.Methods:The subgingival plaque(Sp)and prostatic fluid(Pf)of patients with BPH concurrent periodontitis were extracted and cultured for 16S r DNA sequencing.Ligature-induced periodontitis,testosterone-induced BPH and the composite models in rats were established.The P.gingivalis and its toxic factor P.gingivalis lipopolysaccharide(P.gLPS)were injected into the ventral lobe of prostate in rats to simulate its colonization of prostate.P.g-LPS was used to construct the prostate cell infection model for mechanism exploration.Results:P.gingivalis,Streptococcus oralis,Capnocytophaga ochracea and other oral pathogens were simultaneously detected in the Sp and Pf of patients with BPH concurrent periodontitis,and the average relative abundance of P.gingivalis was found to be the highest.P.gingivalis was detected in both Sp and Pf in 62.5%of patients.Simultaneous periodontitis and BPH synergistically aggravated prostate histological changes.P.gingivalis and P.gLPS infection could induce obvious hyperplasia of the prostate epithelium and stroma(epithelial thickness was 2.97-fold and 3.08-fold that of control group,respectively),and increase of collagen fibrosis(3.81-fold and 5.02-fold that of control group,respectively).P.gingivalis infection promoted prostate cell proliferation,inhibited apoptosis,and upregulated the expression of inflammatory cytokines interleukin-6(IL-6;4.47-fold),interleukin-6 receptor-α(IL-6Rα;5.74-fold)and glycoprotein 130(gp130;4.47-fold)in prostatic tissue.P.g-LPS could significantly inhibit cell apoptosis,promote mitosis and proliferation of cells.P.g-LPS activates the Akt pathway through IL-6/IL-6Rα/gp130 complex,which destroys the imbalance between proliferation and apoptosis of prostate cells,induces BPH.Conclusion:P.gingivalis was abundant in the Pf of patients with BPH concurrent periodontitis.P.gingivalis infection can promote BPH,which may affect the progression of BPH via inflammation and the Akt signaling pathway.
基金supported by National Natural Science Foundation of China(No.31440027)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2014133)+2 种基金Natural Science Foundation for Young Scientists of Shanxi Province,China(No.2011021007-3)the Science and Technology Innovation Found of Shanxi Medical University(No.C01201008)the Program for the Top Science and Technology Innovation Teams of Higher Learning Institutions of Shanxi Province,China
文摘In the present study, two new limonoids, 1α, 7α-dihydroxyl-3α-acetoxyl-12α-ethoxylnimbolinin(1) and 1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12β-ethoxylnimbolinin(2), together with other four known limonoids(3-6), were isolated from the fruits of Melia toosendan. Their structures were elucidated by means of extensive spectroscopic analyses(NMR and ESI-MS) and comparisons with the data reported in the literature. The isolated compounds were evaluated for their antibacterial activities. Compound 4 exhibited significant antibacterial activity against an oral pathogen, Porphyromonas gingivalis ATCC 33277, with an MIC value of 15.2 μg·m L-1. Compound 2 was also active against P. gingivalis ATCC 33277, with an MIC value of 31.25 μg·m L-1. In conlcusion, our resutls indicate that these compounds may provide a basis for future development of novel antibiotics.
