The effect of nicotine and cotinine on human gingival fibroblasts attachment to root surfaces

Comparative effect of anthocyanin on proliferation and migration of human gingival fibroblasts in the absence or presence of nicotine

Background

Oral fibroblast malfunction can result in periodontal diseases. Nicotine can prolong the healing process as an irritant of oral tissues. Anthocyanins have been demonstrated to have potential benefits in preventing or treating smoking-related periodontal diseases. Cyanidin chloride's (CC's) potential in oral wound healing and the viability, proliferation, and migration of human gingival fibroblasts (HGFs) were examined in the presence and absence of nicotine by an in vitro study.

Methods

The effects of different nicotine concentrations (1, 2, 3, 4, and 5 mM) on the viability and proliferation of HGF cells were evaluated in the presence and absence of different CC concentrations (5, 10, 25, and 50 μM) using the quantitative MTT assay. The scratch test was performed to evaluate the migration of CC-treated cells in the presence of 2.5-mM nicotine.

Results

No cytotoxicity was observed at 1‒100 μM CC concentrations after 24, 48, and 72 hours of exposure to HGF cells. However, a concentration of 200 μM significantly reduced cell viability by about 20% at all the three-time intervals (P<0.05). Also, 3‒5-mM concentrations of nicotine significantly reduced cell viability in a dose- and time-dependent manner. Moreover, the understudied CC concentrations decreased nicotine's adverse effects on cell migration to some extent.

Conclusion

Although the understudied CC concentrations could not significantly reduce the adverse effects of understudied nicotine concentrations on the viability and proliferation of HGF cells, they were able to reduce the detrimental effects of nicotine on cell migration significantly.

Comparison of severity of periodontal clinical parameters among naswar/snuff users: Cross sectional study

Background

Naswar is a moist, non-chewable, and smokeless tobacco product ensconced in the buccal vestibule or floor of the mouth. Consumption of naswar is very popular in South Asia, especially Pakistan. This cross-sectional study compared the periodontal clinical parameters amongst mild, moderate, and severe naswar users.

Methods

318 naswar users, categorized into three equal groups (n = 106) severe naswar users, moderate naswar users, and mild naswar users were drawn for this study. Bleeding on probing, pocking depth, gingival recession, and attachment loss were assessed using the UNC-15 probe and compared among the three groups of naswar users. Data analysis was done with the help of SPSS. Statistical significance was deliberated at p value ≤0.05.

Results

28.9 ± 7.6 years was the mean age presentation. The mean % of bleeding on probing score was 61.95% in severe naswar users, 56.62% in moderate naswar users, and 51.23% in mild naswar users with a p-value of 0.001*. In severe, moderate, and mild naswar users the probing pocket depth (4-6mm) were 35.14%, 30.95%, and 23.21% respectively. 26.78% severe naswar users were having mean percentage for probing pocket depth (>6m) followed by moderate naswar users (17.26%) and mild naswar users (17.26%) with a significant p-value (0.001*). Clinical attachment loss (CAL) was 2.50 percent in light naswar users, 3.0 percent in moderate naswar users, and 4.25 percent in severe naswar users. Clinical attachment loss (CAL) was 2.50 percent in light naswar users, 3.0 percent in moderate naswar users, and 4.25 percent in severe naswar users. Severe naswar users had a high mean percentage of gingival recession (23.21%), whereas light 13.67 percent and moderate 14.88 percent naswar users had a smaller difference.

Conclusions

Clinical periodontal parameters were more worsen in heavy naswar users compared to moderate and light naswar users.

Fluorosilicic acid and cotinine, separately and in combination, induce genotoxicity and telomeric reduction in human osteoblast cell line MG63

Skeletal fluorosis is a severe case in which bone deformations and bone tissue weakening occur due to excessive fluorine deposition. Recently, data on smoking have been published that smoke constituents can indirectly influence bone mass and interfere in the metabolism of fluorides in humans. Thus, the present in vitro study aimed to assess the genetic instability in human osteoblast MG63 cells exposed to fluorosilicic acid (FA) and cotinine (COT), separately and in combination, in concentrations found in human plasma. For this, cell cytotoxicity was performed by MTT assay; DNA damage was performed by alkaline comet assay (CA), modified by repair endonucleases (+FPG); micronuclei test (MN) using CBMN-Cyt assay; and telomere length (TL) by qPCR in MG63 cells. No cytotoxicity was observed for all concentrations tested in this study. Alkaline CA results showed a significant increase in DNA damage at all FA concentrations (0.03125-0.300 mg/L), in the two highest concentrations of COT (125 and 250 ng/mL), and the highest concentration of FA+COT (0.300 mg/L+250 ng/mL). Alkaline CA+FPG test was used to detect oxidized nucleobases, which occurred at the two highest concentrations of FA, COT, and FA+COT. Micronuclei test showed an increase in the frequency of MN at all concentrations of FA (0.075-0.300 mg/L) except in the lowest concentration (0.03125 mg/L), in the two highest concentrations of COT (125 and 250 ng/mL), and all concentrations of FA+COT. There was no significant difference in nuclear division index, binucleated cells, nucleoplasmic bridge, and nuclear bud. A TL reduction was observed in cells treated with the highest concentrations of FA alone (0.300 mg/L) and FA+COT (0.300 mg/L+250 ng/mL). Finally, our study showed that FA and COT (mainly alone) at concentrations found in human plasma induced oxidative damage and genetic instability in human osteoblast cells.

Evaluation of cytotoxicity of areca nut and its commercial products on normal human gingival fibroblast and oral squamous cell carcinoma cell lines

Consumption of areca nut products is the most common cause of oral cancers, particularly in South Asian countries. This study evaluates the cytotoxic and necrotizing effects of areca nut and its formulations on normal human gingival fibroblasts (HGF-1) and oral squamous cell carcinoma (OSCC, CAL-27) cell lines. Identification of various carcinogens and adulterants using LC-HR-ESI-MS/MS analysis was performed in the extracts of areca nut and its products. Apart from alkaloids and flavonoids, a major adulterant, saccharin was found in all the samples of chalia (one of the most common chewing products of areca nut) in the ranges between 1.697-7.170 mg/g of the sample. Cytotoxic studies showed that most of the areca nut products were found cytotoxic to HGF-1 cells while being relatively non-cytotoxic against CAL-27 cells, rather they promote the growth of cancer cells. Our findings revealed that the components of areca nut and its products were injurious to HGF-1 cells and caused necrosis, which may attenuate HGF-1 protection toward oral epithelial cells. Moreover, the non-cytotoxic effect of these products on cancer cell lines suggests further predisposal of the habitual chewers for developing oral carcinomas. This study will give a better understanding of the hazardous effects of areca nut products.

Periodontal Conditions and Whole Salivary IL-17A and -23 Levels among Young Adult Cannabis sativa (Marijuana)-Smokers, Heavy Cigarette-Smokers and Non-Smokers

In the United States, prevalence of marijuana-use has doubled in the past 2 decades. The aim was to compare the periodontal conditions and whole-salivary IL-17A and IL-23 levels among young adult marijuana-smokers, heavy cigarette-smokers and non-smokers. Self-reported marijuana-smokers, heavy-cigarette-smokers, non-smokers with periodontitis and periodontally-healthy non-smokers were included. Demographic data was recorded and full-mouth plaque index (PI), bleeding on probing (BoP), probing depth (PD) and clinical attachment loss (AL), marginal bone loss (MBL) and missing teeth were recorded. Levels of IL-17A and IL-23 levels were measured in the whole saliva. p < 0.01 was considered statistically significant. Fifteen-marijuana-smokers, 15 heavy-cigarette-smokers, 16 non-smokers-with-periodontitis and 15 periodontally-healthy-non-smokers) were included. The clinicoradiographic parameters were worse among marijuana-smokers (p < 0.01), cigarette-smokers (p < 0.01) and non-smokers-with-periodontitis (p < 0.01) than periodontally-healthy-non-smokers. Marijuana- and cigarette-smokers had Stage-IV/Grade C and non-smokers with periodontitis had Stage-III/Grade-C. Salivary IL-17A and IL-23 levels were higher in marijuana-smokers than cigarette-smokers (p < 0.01) and non-smokers-with-periodontitis (p < 0.01). Whole salivary IL-17A and IL-23 levels were higher among cigarette-smokers than non-smokers with periodontitis (p < 0.01) and periodontally-healthy-individuals (p < 0.01). Marijuana- and heavy cigarette-smokers have comparable clinicoradiographic periodontal statuses. This rejects hypothesis-1. However, whole salivary immunoinflammatory response may be moderately worse in marijuana-smokers compared with heavy cigarette-smokers and non-smoker with periodontitis thereby supporting hypothesis-2.

Cytotoxic and genotoxic evaluation of cotinine using human neuroblastoma cells (SH-SY5Y)

Cotinine is the main metabolite of nicotine, which is metabolized in the liver through a cytochrome P450 enzyme. Different studies point to genetic instability caused by nicotine, such as single and double DNA strand breaks and micronuclei formation, but little is known about the effect of cotinine. Therefore, the present in vitro study assessed the effects of cotinine on cell viability and DNA damage in SH-SY5Y neuroblastoma cells, as well as genotoxicity related to oxidative stress mechanisms. Comparisons with nicotine were also performed. An alkaline comet assay modified by repair endonucleases (FPG, OGG1, and Endo III) was used to detect oxidized nucleobases. SH-SY5Y neuronal cells were cultured under standard conditions and exposed for 3 h to different concentrations of cotinine and nicotine. Cytotoxicity was observed at higher doses of cotinine and nicotine in the MTT assay. In the trypan blue assay, cells showed viability above 80% for both compounds. Alkaline comet assay results demonstrated a significant increase in damage index and frequency for cells treated with cotinine and nicotine, presenting genotoxicity. The results of the enzyme-modified comet assay suggest a DNA oxidative damage induced by nicotine. Unlike other studies, our results demonstrated genotoxicity induced by both cotinine and nicotine. The similar effects observed for these two pyridine alkaloids may be due to the similarity of their structures.

Effect of tobacco on periodontal disease and oral cancer

INTRODUCTION

Periodontal disease and oral cancer are common health hazards. Epidemiological investigations show that smoking, periodontal disease and oral cancer are closely related. Tobacco is one of the major risk factors for periodontitis and oral cancer.

METHODS

A systematic literature review was performed. To identify relevant studies, the following online databases were searched using specific keywords: PubMed, Web of Science and CNKI.

RESULTS

Tobacco not only possesses an addictive effect, but it aggravates periodontal disease by promoting the invasion of pathogenic bacteria, inhibiting autoimmune defense, aggravating the inflammatory reaction, and aggravating the loss of alveolar bone. According to current evidence, tobacco significantly aggravates the development and progression of periodontal disease and oral cancer, and periodontal disease may be related to the prevalence of oral cancer.

CONCLUSIONS

Clinicians should strongly recommend that smokers undertake a strategy to stop smoking to avoid the exacerbation of nicotine-related periodontal disease and to reduce the incidence of oral cancer.

Comparative study of the effects of cigarette smoke and electronic cigarettes on human gingival fibroblast proliferation, migration and apoptosis

In an effort to reduce smoking-related diseases, alternative products such as e-cigarettes have been proposed. However, despite their growing popularity, the potential toxicity of e-cigarettes remains largely unknown. In this study, human gingival fibroblasts were repeatedly exposed to cigarette smoke condensate (CSC) and to nicotine-rich (NR) or nicotine-free (NF) e-vapor condensates for 60 min once a day for various time periods. They were then used to perform different analyses. Results indicate that cells exposed to CSC or NR condensates showed an altered morphology and a reduced proliferation rate, as ascertained by MTT and BrdU assays. Fibroblast cultures exposed to either CSC or e-vapor condensates also showed increased levels of TUNEL-positive apoptotic cells, compared to that recorded in the control. Furthermore, the cell scratch test revealed that repeated exposures to CSC or to e-vapor condensates delayed both fibroblast migration and wound healing. It should be noted that CSC was much more damageable to gingival fibroblasts than were the NR and NF e-vapor condensates. The representative chain of damage thus translates to CSC > NR e-vapor condensate > NF e-vapor condensate.

Comparison of periodontal inflammatory parameters among habitual gutka-chewers and naswar-dippers: a split-mouth retrospective clinical study

OBJECTIVE

The aim of the present split-mouth retrospective study was to compare the clinical periodontal parameters among gutka-chewers and naswar-dippers.

METHODS

A structured questionnaire was used to record demographic information. Jaw quadrant in which, gutka or naswar were placed were defined as "test-sites". The remaining jaw quadrants were designated as "control-sites". Clinical [plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment loss (CAL)] and radiographic [alveolar bone loss (ABL)] parameters were compared among gutka-chewers and naswar-dippers in the test- and control sites. Data were analysed using non-parametric Wilcoxon signed rank test followed by post hoc analyses with the Bonferroni correction. p < .05 were considered statistically significant.

RESULTS

Seventy-five gutka-chewers and 72 naswar-dippers with mean ages of 45.2 ± 0.8 years and 47.3 ± 2.8 years, respectively were included. Gutka-chewers and naswar-dippers were consuming their respective smokeless tobacco product 10.2 times and 8.5 times daily for 15.1 ± 2.7 and 12.3 ± 3.4 years, respectively. Among gutka-chewers and naswar-dippers, scores of PI, BOP, PPD ≥4 mm, CAL and ABL were significantly higher in the test-sites compared with their respective control-sites (p < .01).

CONCLUSIONS

Periodontal inflammatory parameters were poorer in the test-sites among gutka-chewers and naswar-dippers compared with the control-sites.