Oral malodorous compound activates mitochondrial pathway inducing apoptosis in human gingival fibroblasts

Non-Surgical Periodontal Treatment Impact on Subgingival Microbiome and Intra-Oral Halitosis

The purpose of this study was to characterize and compare subgingival microbiome before and after periodontal treatment to learn if any changes of the subgingival microbiome were reflected in intra-oral halitosis. We tested the hypothesis that intra-oral halitosis (Volatile sulfur compounds levels) correlates with corresponding subgingival bacterial levels before and after periodontal treatment. Twenty patients with generalized periodontitis completed the study. Subgingival plaque samples were collected at baseline and 6-8 weeks after nonsurgical periodontal therapy. Full-mouth periodontal status assessed probing depth (PD), clinical attachment loss (CAL), gingival recession (REC), bleeding on probing (BoP), PISA and PESA. Halitosis assessment was made using a volatile sulfur compounds (VSC) detector device. Periodontal measures were regressed across VSC values using adjusted multivariate linear analysis. The subgingival microbiome was characterized by sequencing on an Illumina platform. From a sample of 20 patients referred to periodontal treatment, 70% were females (n = 14), with a mean age of 56.6 (±10.3) years; full-mouth records of PD, CAL, BOP (%) allowed to classify the stage and grade of periodontitis, with 45% (n = 9) of the sample having Periodontitis Stage IV grade C and 95% (n = 19) had generalized periodontitis. The correlation of bacterial variation with VSCs measured in the periodontal diagnosis and in the reassessment after treatment were evaluated. Fusobacterium nucleatum, Capnocytophaga gingivalis and Campylobacter showaei showed correlation with the reduction of VSC after periodontal treatment (p-value = 0.044; 0.047 and 0.004, respectively). Capnocytophaga sputigena had a significant reverse correlation between VSCs variation from diagnosis (baseline) and after treatment. Microbial diversity was high in the subgingival plaque on periodontitis and intra-oral halitosis participants of the study. Furthermore, there were correlations between subgingival plaque composition and VSC counting after periodontal treatment. The subgingival microbiome can offer important clues in the investigation of the pathogenesis and treatment of halitosis.

Role of Hydrogen Sulfide in Oral Disease

Oral diseases are among the most common human diseases yet less studied. These diseases affect both the physical, mental, and social health of the patients resulting in poor quality of life. They affect all ages, although severe stages are mostly observed in older individuals. Poor oral hygiene, genetics, and environmental factors contribute enormously to the development and progression of these diseases. Although there are available treatment options for these diseases, the recurrence of the diseases hinders their efficiency. Oral volatile sulfur compounds (VSCs) are highly produced in oral cavity as a result of bacteria activities. Together with bacteria components such as lipopolysaccharides, VSCs participate in the progression of oral diseases by regulating cellular activities and interfering with the immune response. Hydrogen sulfide (H2S) is a gaseous neurotransmitter primarily produced endogenously and is involved in the regulation of cellular activities. The gas is also among the VSCs produced by oral bacteria. In numerous diseases, H2S have been reported to have dual effects depending on the cell, concentration, and donor used. In oral diseases, high production and subsequent utilization of this gas have been reported. Also, this high production is associated with the progression of oral diseases. In this review, we will discuss the production of H2S in oral cavity, its interaction with cellular activities, and most importantly its role in oral diseases.

The Role of Oral Microbiota in Intra-Oral Halitosis

Halitosis is a common ailment concerning 15% to 60% of the human population. Halitosis can be divided into extra-oral halitosis (EOH) and intra-oral halitosis (IOH). The IOH is formed by volatile compounds, which are produced mainly by anaerobic bacteria. To these odorous substances belong volatile sulfur compounds (VSCs), aromatic compounds, amines, short-chain fatty or organic acids, alcohols, aliphatic compounds, aldehydes, and ketones. The most important VSCs are hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, and methyl mercaptan. VSCs can be toxic for human cells even at low concentrations. The oral bacteria most related to halitosis are Actinomyces spp., Bacteroides spp., Dialister spp., Eubacterium spp., Fusobacterium spp., Leptotrichia spp., Peptostreptococcus spp., Porphyromonas spp., Prevotella spp., Selenomonas spp., Solobacterium spp., Tannerella forsythia, and Veillonella spp. Most bacteria that cause halitosis are responsible for periodontitis, but they can also affect the development of oral and digestive tract cancers. Malodorous agents responsible for carcinogenesis are hydrogen sulfide and acetaldehyde.

Efficacy of glycine powder air-polishing combined with scaling and root planing in the treatment of periodontitis and halitosis: A randomised clinical study

Introduction

This study was performed to evaluate the clinical efficacy of using the Perio-Flow device (Electro Medical Systems, Nyon, Switzerland) adjunctively with mechanical instrumentation on periodontal parameters and halitosis.

Materials and Methods

Sixty patients who presented with a 4- to 6-mm probing pocket depth were recruited for the study. Patients were randomly assigned to scaling and root planing (SRP) or SRP + glycine powder air-polishing (GPAP). For both groups, the plaque index, gingival index, pocket depth, bleeding on probing, and clinical attachment level scores were recorded at baseline and 1 month. Volatile sulphur compounds (VSCs) were measured by a Halimeter (Interscan Corp., Chatsworth, CA, USA) at baseline, immediately after treatment, and at 7, 14, and 30 days.

Results

Both groups showed significantly lower plaque index, gingival index, pocket depth, bleeding on probing, and clinical attachment level gain scores at 1 month than at baseline. No significant differences were found between the groups at any time point. The VSCs were significantly different at 1 month compared with baseline in both groups. However, the intergroup comparisons of VSCs were not statistically significant at any time point.

Conclusion

Within the limits of this study, SRP is effective for treatment of periodontitis and halitosis. However, using GPAP adjunctively with mechanical instrumentation has no beneficial effects on halitosis or periodontal parameters.

Halitosis - An overview: Part-I - Classification, etiology, and pathophysiology of halitosis

Halitosis is a condition where the breath is altered in an unpleasant manner for the affected individuals and impairs them socially as well as psychologically. Halitosis can be clinically classified as real halitosis, pseudohalitosis, and halitophobia. Real halitosis has oral and extra-oral etiologies and the pathophysiology involves interaction of anaerobic microbes (mainly) with the proteins present in the oral cavity fluids and contents, resulting in production of volatile sulfur compounds (VSCs). These VSCs, beyond responsible for halitosis, can also initiate and accelerate periodontal disease progression. Thus, this review is about the pathophysiology and various etiologies of halitosis, the knowledge of which can help in the betterment of treatment options.

The differential expression of mgl mRNA by Porphyromonas gingivalis affects the production of methyl mercaptan

OBJECTIVE

A large number of individuals have halitosis. The total amount of volatile sulfur compounds, which are the main cause of halitosis, has been correlated with periodontitis following bacterial infection. In this study, Porphyromonas gingivalis (Pg), a major periodontopathogenic bacterium, was isolated from patients with halitosis by the amplification of 16S rRNA, and the ability of isolated Pg to produce methyl mercaptan (CH3 SH) was determined to clarify the relationship between halitosis and Pg infection.

MATERIALS AND METHODS

CH3 SH concentrations were measured in patients using Oral Chroma. The production of CH3 SH by Pg standard and clinical strains was also measured in vitro. Real-time PCR was performed to compare the expression of mgl mRNA (which encoded l-methionine-a-deamino-g-mercaptomethane-lyase) among the Pg strains. The production of CH3 SH and the expression of mgl mRNA were also determined to assess the effects of oriental medicine.

RESULTS

The production of CH3 SH and the expression of mgl mRNA strongly correlated with each other in the presence of l-methionine. The expression of mgl mRNA by Pg W83 was strongly inhibited by magnoliaceae.

CONCLUSION

The production of CH3 SH was correlated with the expression of mgl. Furthermore, the oriental medicine, magnoliaceae, may represent a potential treatment for halitosis.

Microbial volatile compounds in health and disease conditions

Microbial cultures and/or microbial associated diseases often have a characteristic smell. Volatile organic compounds (VOCs) are produced by all microorganisms as part of their normal metabolism. The types and classes of VOC produced is wide, including fatty acids and their derivatives (e.g. hydrocarbons, aliphatic alcohols and ketones), aromatic compounds, nitrogen containing compounds, and volatile sulfur compounds. A diversity of ecological niches exist in the human body which can support a polymicrobial community, with the exact VOC profile of a given anatomical site being dependent on that produced by both the host component and the microbial species present. The detection of VOCs is of interest to various disciplines, hence numerous analytical approaches have been developed to accurately characterize and measure VOCs in the laboratory, often from patient derived samples. Using these technological advancements it is evident that VOCs are indicative of both health and disease states. Many of these techniques are still largely confined to the research laboratory, but it is envisaged that in future bedside 'VOC profiling' will enable rapid characterization of microbial associated disease, providing vital information to healthcare practitioners.

Identification of an L-methionine γ-lyase involved in the production of hydrogen sulfide from L-cysteine in Fusobacterium nucleatum subsp. nucleatum ATCC 25586

Fusobacterium nucleatum produces an abundance of hydrogen sulfide (H(2)S) in the oral cavity that is mediated by several enzymes. The identification and characterization of three distinct enzymes (Fn0625, Fn1055 and Fn1220) in F. nucleatum that catalyse the production of H(2)S from l-cysteine have been reported. In the current study, a novel enzyme involved in the production of H(2)S in F. nucleatum ATCC 25586, whose molecular mass had been estimated to be approximately 130 kDa, was identified by two-dimensional electrophoresis combined with MALDI-TOF MS. The enzyme, Fn1419, has previously been characterized as an l-methionine γ-lyase. SDS-PAGE and gel-filtration chromatography indicated that Fn1419 has a molecular mass of 43 kDa and forms tetramers in solution. Unlike other enzymes associated with H(2)S production in F. nucleatum, the quaternary structure of Fn1419 was not completely disrupted by exposure to SDS. The purified recombinant enzyme exhibited a K(m) of 0.32±0.02 mM and a k(cat) of 0.69±0.01 s(-1). Based on current and published data, the enzymic activity for H(2)S production from l-cysteine in F. nucleatum is ranked as follows: Fn1220>Fn1055>Fn1419>Fn0625. Based on kinetic values and relative mRNA levels of the respective genes, as determined by real-time quantitative PCR, the amount of H(2)S produced by Fn1419 was estimated to be 1.9 % of the total H(2)S produced from l-cysteine in F. nucleatum ATCC 25586. In comparison, Fn1220 appeared to contribute significantly to H(2)S production (87.6 %).

Oral malodorous compound causes oxidative stress and p53-mediated programmed cell death in keratinocyte stem cells

BACKGROUND

It is well known that hydrogen sulfide (H(2)S), the main substance causing physiologic halitosis, is also involved in the etiology of periodontitis. Gingival crevicular epithelium is the first barrier against periodontal pathogens and their products; keratinocyte stem cells play key roles in maintaining this barrier. An increased apoptotic process can affect keratinocyte stem cells, having a direct impact on oral epithelial tissue architecture. Our objective is to determine whether H(2)S induces apoptosis in human keratinocyte stem cells.

METHODS

Apoptosis levels; p53 activity; reactive oxygen species; mitochondrial membrane depolarization; cytochrome C release; and caspase-9, -8, and -3 were assessed using enzyme-linked immunosorbent assay and flow cytometry. Genomic DNA damage was examined using single-cell gel electrophoresis. Real-time polymerase chain reaction was used for Bax detection.

RESULTS

The percentage of apoptotic cells was significantly increased (20.5% +/- 1.6% versus 4.5% +/- 1.1% at 24 hours and 37.8% +/- 5.4% versus 4.8% +/- 0.9% at 48 hours; P <0.05, respectively; n = 5). Mitochondrial membrane potential was collapsed and reactive oxygen species levels were significantly increased compared to their control groups. At each time point the amount of released cytochrome C into the cytosol was significantly increased. Caspase-9 and -3 activities were significantly increased (P <0.05), whereas caspase-8 remained inactive. After both 24 and 48 hours, total and phosphorylated p53 levels were significantly increased.

CONCLUSION

We conclude that H(2)S can induce apoptosis in human keratinocyte stem cells, a key component of the epithelial barrier, following DNA damage and p53 activation.