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1.
Int J Clin Pediatr Dent ; 16(3): 431-436, 2023.
Article in English | MEDLINE | ID: mdl-37496932

ABSTRACT

Aim and objectives: The present study was intended to assess the biocompatibility of newly formulated materials such as zinc oxide (ZO) admixed with ajwain oil (A) as well as ajwain eugenol (E) (1:1 ratio) against ZOE through an animal model as root canal obturating materials in deciduous teeth. Materials and methods: The study involved randomly selected 24 albino rats, which were divided into three groups based on test materials. Two polyethylene tubes (PETT) (8 mm long × 1 mm internal diameter) were inserted into connective tissues of the dorsal side on either side of each rat viz empty tube (negative control) and another containing test material (test group). Animals were sacrificed at the end of the 7th and 21st days. PETT with surrounding connective tissues were excised. Histopathological evaluations of the material's biocompatibility were done by determining inflammatory tissue responses. Non-parametric tests such as Kruskal-Wallis and Mann-Whitney U were used for statistical analysis (p < 0.05). Results: Histopathological examination on the 7th day showed increased polymorphonuclear cells for all test materials compared to the negative control (p = 0.92), suggesting acute inflammation. The inflammation subsided gradually after 21 days (p = 0.48). The lymphocytes increased after 21 days for all the materials indicating chronic inflammation (p = 0.79), as well as fibroblasts (p = 0.34) and capillaries (p = 0.35), indicating healing and repair. Conclusion: The newly formulated obturating materials were found to be biocompatible compared to ZOE. How to cite this article: Dahake PT, Joshi SS, Kale YJ, et al. Biocompatibility of Ajwain Oil Combined with Eugenol and Zinc Oxide as a Deciduous Root Canal Obturating Material: An In Vivo Study. Int J Clin Pediatr Dent 2023;16(3):431-436.

2.
Saudi Dent J ; 34(7): 544-552, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36267530

ABSTRACT

Objectives: This study aimed to evaluate and compare the cell viability, differentiation potential and anti-inflammatory potential of propolis and Biodentine™ on stem cells isolated from human exfoliated deciduous teeth (SHED). Materials and methods: SHED were segregated and cultured from the dental pulp of children after therapeutic extraction. Microculture Tetrazolium Assay (MTT) assay was carried out for assessing cell proliferation potential of propolis and Biodentine at different concentrations. As per the results from cell proliferation assay, cell differentiation potential of SHED was evaluated at concentration of 12.5 µg/ml using Alizarin Red staining. The anti-inflammatory potential of test materials was evaluated using gelatin zymography by detecting MMP-2 and MMP-9. Results: The maximum cell proliferation percentage of SHED treated with propolis and Biodentine was observed at a concentration of 12.5 µg/ml, on day 7, 14 and 21 with Biodentine having maximum cell proliferation potential followed by propolis. SHED treated with Biodentine showed maximum cell differentiation on day 7 (107.16), 14 (106.29) and 21 (107.72). However, anti-inflammatory activity against MMP-2 was 95 % with propolis and 85 % with Biodentine and whereas, against MMP-9 it was 65 % for propolis and 47 % for Biodentine. Conclusion: Propolis shows comparable cell viability, cell proliferation and differentiation potential on SHED when compared to Biodentine. It also exhibits better invitro anti-inflammatory activity on SHED compared to Biodentine. Further studies are warranted to validate the application of propolis as an effective and economical alternative biocompatible agent to Biodentine for vital pulp therapies.

3.
Int J Clin Pediatr Dent ; 15(5): 514-519, 2022.
Article in English | MEDLINE | ID: mdl-36865731

ABSTRACT

Objective: This study aimed to evaluate the antimicrobial effect of sodium hypochlorite (NaOCl), Triphala, Eucalyptus, and carvacrol on Enterococcus faecalis as the most common microorganism isolated from infected root canals. Materials and methods: Seventy-five mandibular premolar teeth were randomly distributed into five study groups: 5.25% NaOCl, 10% Triphala, 1.25% Eucalyptus, 0.6% carvacrol, and negative control (saline) group. Samples were taken using paper points from the canal spaces and using Gates-Glidden (GG) drills from dentinal tubules; after sample culturing, the colony forming unit (CFU) were counted, which was analyzed by the Wilcoxon signed-rank test. Results: All irrigants have shown a reduction of microorganisms in the root canal space. After the use of NaOCl and Eucalyptus, the bacterial count was significantly reduced in the canal, as well as dentin sampling, as compared to Triphala and carvacrol. The antimicrobial efficiency of all irrigants against E. faecalis revealed a significant difference (p < 0.05). Conclusion: All irrigants exerted significant antimicrobial activity against E. faecalis. Around 1.25% of Eucalyptus was the most effective irrigant than 5.25% of NaOCl, Triphala, and carvacrol. How to cite this article: Panchal VV, Dahake PT, Kale YJ, et al. Comparative Evaluation of Antimicrobial Efficacy of Sodium Hypochlorite, Triphala, Eucalyptus, and Carvacrol against Enterococcus faecalis: An In Vitro study. Int J Clin Pediatr Dent 2022;15(5):514-519.

4.
Int J Clin Pediatr Dent ; 15(6): 643-651, 2022.
Article in English | MEDLINE | ID: mdl-36866129

ABSTRACT

Aim: To investigate the cariostatic and remineralizing effect of two commercial silver diamine fluoride (SDF) preparations on enamel and dentinal caries using a bacterial plaque model. Materials and methods: A total of 32 extracted primary molars were divided into two groups (n = 16), group I (FAgamin), and group II (SDF). Plaque bacterial model was used to induce caries on enamel and dentin. Preoperative evaluation of samples was done using confocal laser microscopy (CLSM) and energy-dispersive X-ray spectroscopy-scanning electron microscope (EDX-SEM). All samples were treated with test materials and evaluated for postoperative remineralization quantification. Results: Energy-dispersive X-ray spectroscopy (EDX) revealed that mean preoperative levels (in weight %) of silver (Ag) and fluoride (F2) in carious enamel lesions were 0.0 and 0.0, which increased postoperatively to 11.40 and 31.05 for FAgamin and 13.61 and 31.87 for SDF, respectively. For dentinal caries, EDX revealed mean preoperative levels (in weight %) of Ag and F2 were 0.0 and 0.0, which increased to 11.47 and 48.71 for FAgamin and 10.16 and 47.82 for SDF, respectively postoperatively. Both the groups showed evident demineralization with exposed collagen under SEM. The mean value of enamel lesion depth for the group I and II were 38.64 and 39.30 µm, that reduced to 28.02 and 28.70 µm while for dentinal caries, the mean depth from 38.05 and 38.29 µm that reduced significantly to 28.96 and 30.10 µm, respectively (p < 0.001). Caries depth declined significantly after the application of both FAgamin and SDF (p < 0.001). Conclusion: FAgamin and SDF show similar cariostatic and remineralization potential for dental caries. The bacterial plaque model used in this study is an efficient method to induce artificial carious lesions in teeth. Clinical significance: A comparative evaluation of these two cariostatic and remineralizing agents will aid in identifying the efficacy of both commercial products in treating initial caries lesions in an effective noninvasive and child-friendly manner. How to cite this article: Kale YJ, Misal S, Dadpe MV, et al. Comparison of Cariostatic and Remineralizing Potential of Two Commercial Silver Diamine Fluoride Preparations using Confocal Laser Microscopy and EDX-SEM Spectroscopy: An In Vitro study. Int J Clin Pediatr Dent 2022;15(6):643-651.

5.
Int J Clin Pediatr Dent ; 15(4): 442-449, 2022.
Article in English | MEDLINE | ID: mdl-36875974

ABSTRACT

Aim: To investigate the cariostatic and remineralizing effect of two commercial silver diamine fluoride (SDF) preparations on enamel and dentinal caries using a plaque bacterial model. Materials and methods: Thirty-two extracted primary molars were divided into two groups (n = 16) as group I (Advantage Arrest) and group II (e-SDF). Plaque bacterial model was used to induce caries on enamel and dentin. Preoperative evaluation of samples was done using confocal laser scanning microscopy (CLSM) and energy-dispersive X-ray spectroscopy-scanning electron microscope (EDX-SEM). All samples were treated with test materials and evaluated for postoperative remineralization quantification. Results: EDX revealed that mean preoperative levels (in weight%) of silver (Ag) and fluoride (F) in enamel carious lesions were 0.0 and 0.0, which increased postoperatively to 11.40 and 31.05 for Advantage Arrest and 13.61 and 31.87 for e-SDF, respectively. For dentinal caries, EDX revealed mean preoperative levels (in weight%) of Ag and F were 0.0 and 0.0, which increased to 11.47 and 48.71 for Advantage Arrest and 10.16 and 47.82 for e-SDF, respectively postoperatively. Both groups showed evident demineralization with exposed collagen under SEM. The mean values of enamel lesion depth for the group I and II were 38.64 and 39.30 µm, that reduced to 28.02 and 28.70 µm, while for dentinal caries, the mean depth from 38.05 to 38.29 µm that reduced significantly to 28.96 and 30.10 µm, respectively (p < 0.001). Caries depth declined significantly after the application of both Advantage Arrest and e-SDF (p < 0.001). Conclusion: Advantage arrest and e-SDF show similar cariostatic and remineralization potential for dental caries. The plaque bacterial model used in this study is an efficient method to induce artificial carious lesions in teeth. How to cite this article: Kale YJ, Misal S, Dadpe M, et al. Comparative Evaluation of Cariostatic and Remineralizing Potential of Two Commercial Silver Diamine Fluoride Preparations Using Confocal Laser Microscopy and EDX-SEM Spectroscopy: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(4):442-449.

6.
Saudi Dent J ; 32(1): 43-51, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31920278

ABSTRACT

INTRODUCTION: Stem cells have unmatched capacity and potential for regeneration and when used alone or in combination with scaffolds to replace or repair damaged cells, can differentiate into any mature cell. AIM: To evaluate the functional differentiation potential of EMD (Enamel Matrix Derivative), MTA (Mineral Trioxide Aggregate) and Biodentine on Stem Cells from Human Exfoliated Deciduous teeth (SHED). OBJECTIVE: To determine functional differentiation potential (osteogenic/odontogenic) of various biomaterials on SHED. MATERIAL AND METHOD: SHED derived from 5th linear passage after sub-culturing were treated with EMD, MTA and Biodentine individually and their effect on cell viability was compared and evaluated by MTT (3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) assay for 7 days. Alizarin red S staining was used to assess mineralization potential of these materials by the staining calcium deposits for 14 days. The results were analyzed using One-way ANOVA, Post hoc Tukey's test for multiple comparisons. RESULTS: It was observed that EMD imparted the highest cell viability at the end of 7 days (p < 0.001) followed by Biodentine and MTA. Likewise EMD showed highest potential to enhanced mineralization and expression of dentine sialoprotein (p < 0.001) followed by Biodentine and MTA at the end of 14 days (p<0.001). CONCLUSION: It can be concluded that all the tested materials are bioinductive to SHED. EMD can be used for various vital pulp therapies as that of Biodentine and MTA with predictable as well as enhanced success rate.

7.
J Indian Soc Pedod Prev Dent ; 37(2): 151-156, 2019.
Article in English | MEDLINE | ID: mdl-31249178

ABSTRACT

INTRODUCTION: Various liquid drug formulations are prescribed to the children. Frequent use of these drugs can result in staining of dental restorations, affecting their longevity and durability. AIM: This study aims to evaluate the effect of different pediatric drug formulations on color stability of various esthetic restorative materials. MATERIALS AND METHODS: Three different restorative materials namely composite resin, Zirconomer Improved, and conventional glass ionomer cement (GIC) were used to prepare total 120 (40 from each) disc-shaped specimens having dimensions 12 mm × 1.5 mm. The specimens of each material were divided into five experimental groups (n = 8) through stratified random sampling technique and were immersed in five different liquid medications: Group 1 - amoxicillin + clavulanic acid, Group 2 - metronidazole, Group 3 - cephalexin, Group 4 - ibuprofen, and Group 5 - ibuprofen + paracetamol. All samples were agitated for 2 min and cycle was repeated eight hourly for 1 week with intermittent pH cycling to simulate conditions similar to the oral environment. Color stability of all specimens was evaluated using spectrophotometer. One-way ANOVA and Tukey's post hoc HSD test were used for statistical analysis. RESULTS: Results obtained revealed that Δ E* (color difference) elevation was significantly low with GIC (P < 0.001) and high with composite for all five groups. Amoxicillin + clavulanic acid and metronidazole group showed highest color stainability among all groups. CONCLUSION: GIC showed better color stability with all drug formulations. The highest color alteration was observed in composite resin, whereas zirconia reinforced GIC showed color stability lesser than GIC but better than composite.


Subject(s)
Glass Ionomer Cements , Resin Cements , Child , Composite Resins , Drug Compounding , Esthetics, Dental , Humans , Materials Testing , Zirconium
8.
Saudi Dent J ; 31(1): 76-83, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30723364

ABSTRACT

INTRODUCTION: Numerous antimicrobial agents are used to eliminate oral biofilm. However due to emergence of multi drug resistant microorganisms, the quest to find out biologically safe and naturally available antimicrobial agents continues. AIM: To evaluate antimicrobial efficacy of silver nano-particles against five common oral pathogenic bacteria. OBJECTIVE: To determine antimicrobial activity of silver nanoparticles and chlorhexidine gluconate against oral pathogenic bacteria. MATERIAL AND METHOD: We used strains of Streptococcus mutans (MTCC 497), Streptococcus oralis (MTCC 2696), Lactobacillus acidophilus (MTCC 10307), Lactobacillus fermentum (MTCC 903), and Candida albicans (MTCC 183). We used commercially available silver nanoparticles (experimental group) and chlorhexidine gluconate (positive control). We determined minimum inhibitory concentration (MIC) minimum bactericidal concentration (MBC) of both agents and analyzed the data using paired 't' test, one way ANOVA and Tucky's post Hoc HSD. RESULT: Silver nanoparticles inhibited bacterial growth moderately. The mean MIC of AgNP against S. mutans was 60 ±â€¯22.36 µg/ml, S. oralis - 45 ±â€¯11.18 µg/ml, L. acidophilus - 15 ±â€¯5.59 µg/ml, L. fermentum - 90 ±â€¯22.36 µg/ml, Candida albicans - 2.82 ±â€¯0.68 µg/ml respectively. For chlorhexidine gluconate, mean MIC for S. mutans was 300 ±â€¯111.80 µg/ml, S. oralis - 150 ±â€¯55.90 µg/ml, L. acidophilus - 450 ±â€¯111.80 µg/ml, L. fermentum - 450 ±â€¯111.80 µg/ml and Candida albicans - 150 ±â€¯55.90 µg/ml. MIC and MBC values of AgNP were significantly lower than chlorhexidine gluconate and statistically significant (p < 0.05). CONCLUSION: Silver nanoparticles exhibited better bacteriostatic and bactericidal effect with concentration less than five folds as compared to chlorhexidine. Silver nanoparticles when used in appropriate concentration as safe alternative to present chemically derived other antimicrobial agents.

9.
J Indian Soc Pedod Prev Dent ; 36(4): 357-363, 2018.
Article in English | MEDLINE | ID: mdl-30324925

ABSTRACT

INTRODUCTION: Plaque removal is of utmost importance for control of dental caries and other associated diseases of oral cavity. However, various natural agents have proven their efficacy over chemotherapeutic agents in terms of antibacterial activity against various microorganisms. The effect is mainly due to polyphenol as its major constituent. AIM: In this in vitro study, we aimed to determine the antibacterial efficacy of Trachyspermum ammi oil at different concentrations against five oral bacteria. HYPOTHESIS: Herbal compound, T. ammi oil is effective in reducing five oral plaque-forming bacteria. MATERIALS AND METHODS: We determined the antimicrobial activity of T. ammi oil (test material) against chlorhexidine (gold standard). Pure cultures of Streptococcus mutans MTCC No 497, Streptococcus oralis MTCC No. 2696, Lactobacillus acidophilus MTCC No. 10307, Lactobacillus fermentum MTCC No. 903, and Candida albicans MTCC No. 183 were obtained and grown in selective culture media. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of both materials were evaluated by serial dilution and disc diffusion method, respectively. RESULTS: Our results revealed that T. ammi oil moderately inhibits bacterial growth with mean MIC of 250, 125, 250, 125, and 250 µg/ml, respectively. Mean MBC for T. ammi oil obtained was 18.60 ± 0.65, 11.60 ± 1.14, 14.10 ± 0.55, 11.50 ± 0.61, and 15.10 ± 0.74 mm. The MIC and MBC values were higher as compared to chlorhexidine gluconate and it was statistically significant. CONCLUSION: T. ammi (ajwain) can serve as a potential, natural, nontoxic, and economical therapeutic antiplaque agent.


Subject(s)
Anti-Bacterial Agents/pharmacology , Anti-Infective Agents, Local/pharmacology , Chlorhexidine/pharmacology , Chlormadinone Acetate/pharmacology , Mestranol/pharmacology , Mouth/microbiology , Spiro Compounds/pharmacology , In Vitro Techniques , Microbial Sensitivity Tests
10.
Contemp Clin Dent ; 7(3): 409-12, 2016.
Article in English | MEDLINE | ID: mdl-27630512

ABSTRACT

The purpose of this paper is to describe the case of surgical management of massive compound odontoma with 36 denticles in a 9-year-boy who presented with a complaint of pain and swelling in mandibular left posterior region and retained 74. The denticles were removed after the removal of retained 74 completely and wound healing was observed. Odontomas are considered as hamartomatous dental malformation rather than true neoplasm of odontogenic origin. They are the most commonly occurring abnormally formed dental tissues that interfere with eruption of associated teeth. The eruption disturbances seen due to odontomas are delayed eruption or deflection of associated teeth. These malformations are usually asymptomatic and discovered during routine radiographic investigations. Correct diagnosis followed by proper treatment plan results in a favorable prognosis.

11.
BMJ Case Rep ; 20152015 Dec 18.
Article in English | MEDLINE | ID: mdl-26682836

ABSTRACT

Presence or eruption of teeth immediately at or after birth is a rarely reported phenomenon. This condition is referred to as natal teeth, neonatal teeth, congenital teeth, fetal teeth, predeciduous teeth and dentitia praecox. The most affected teeth are lower primary central incisors with the incidence of 1:2000 for natal and 1:3500 for neonatal teeth. The aetiology of this anomaly is still not clear, however, attributes have been reported in relation to congenital teeth, multiple factors and some syndromes. The management of such cases depends on clinical characteristics of natal or neonatal teeth, as well as complications that they might cause. The aim of this paper is to discuss a rare case of occurrence of two natal teeth in both premature dizygotic twin female babies with specific emphasis on the literature review related to concerns regarding prevalence, aetiology, clinical characteristics, differential diagnosis, complications and management.


Subject(s)
Natal Teeth , Twins, Dizygotic , Female , Humans , Infant, Newborn , Infant, Premature
12.
J Clin Diagn Res ; 9(9): ZC56-60, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26501014

ABSTRACT

INTRODUCTION: Dentistry has found practically the best available aesthetic answer, is ceramic restoration. There are various factors that contribute to the success of ceramic veneers, like colour of underlying tooth, thickness if ceramics and the type of underlying luting cement. Shade selection and matching remains still challenge, however the shade of luting agent used for cementation of veneers produces a change in resultant shade of veneers. AIM: To compare and analyze the spectrophotometric effect of opaque and transparent luting agent on resultant shade of ceramic veneers made of 2L1.5 shade (Vitapan 3D-Masters) and B2 shade (Vitapan Classic). MATERIALS AND METHODS: Out of 15 ceramic veneers of 2L1.5 shade (VITAPAN 3D- Master), seven teeth cemented with opaque cement and eight teeth with transparent cement shade of dual cure resin cement (Variolink II(TM)). Out of 10 ceramic veneers of B2 shade (VITAPAN Classic), five teeth were cemented with opaque cement and other five teeth with transparent cement shade of dual cure resin cement (Variolink II(TM)). Spectrophotometric (Macbeth U.S.A.) analysis of all ceramic veneer crowns done with optiview software and readings were recorded in Commission Internationale de I' Eclairge {CIELAB} system and dE value was calculated. STATISTICAL ANALYSIS: Statistical analysis was done by using Paired t-test. RESULTS: Spectrophotometric analysis of all the veneers cemented with opaque luting agent were lighter in shade due to significant change in dL value. Veneers cemented with transparent luting agent were darker in shade due to significant change in the dL value. CONCLUSION: Opaque luting agent gives lighter shade and transparent luting agent gives darker shade to ceramic veneers fabricated with 2L1.5 and B2 shades.

13.
J Int Oral Health ; 6(1): 48-54, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24653603

ABSTRACT

BACKGROUND: Ceramic veneer fracture has occurred mainly at the incisal edge of the veneer because of greater stress. This study compares and evaluates the fracture resistance ceramic veneers with three different incisal preparations. MATERIALS & METHODS: 15 human permanent maxillary central incisor extracted were selected which were divided into three groups of 5 each having a different Incial design Preparation. Group 1: No Incisal reduction with facio- incisal bevel, Group 2 : 1 mm incisal reduction with butt joint, Group 3 : 1 mm incisal reduction with 1 mm height of Palatal chamfer. It was found that Group III had greater fracture resistance as compared to Group I and Group II. Group I had least fracture resistance as compared to Group II and III. Group II had greater fracture resistance as compared to Group I but less than Group III. RESULTS: Ceramic veneer with 1mm incisal reduction with 1mm height of palatal chamfer showed highest fracture resistance as compared to 1mm incisal reduction with butt joint and no incisal reduction with facial-incisal bevel, in order to achieve better esthetic and functional results. CONCLUSION: The palatal chamfer margin results in preservation of some peripheral enamel layer, which eliminates the micro leakage at the palatal margin-restoration interface and also effectively counteracting shear stress. This design provides a definite seat for cementation. How to cite the article: Jankar AS, Kale Y, Kangane S, Ambekar A, Sinha M, Chaware S. Comparative evaluation of fracture resistance of Ceramic Veneer with three different incisal design preparations - An In-vitro Study. J Int Oral Health 2014;6(1):48-54.

14.
Drug Dev Ind Pharm ; 40(5): 680-90, 2014 May.
Article in English | MEDLINE | ID: mdl-24592893

ABSTRACT

OBJECTIVE: The purpose of this work was to develop and evaluate buccoadhesive tablets of timolol maleate (TM) due to its potential to circumvent the first-pass metabolism and to improve its bioavailability. METHODS: The tablets were prepared by direct compression using two release modifying polymers, Carbopol 974P (Cp-974p) and sodium alginate (SA). A 3(2) full factorial design was employed to study the effect of independent variables, Cp-974p and SA, in various proportions in percent w/w, which influences the in vitro drug release and bioadhesive strengths. Physicochemical properties of the drug were evaluated by ultraviolet, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and powder X-ray diffraction (P-XRD). Tablets were evaluated for hardness, thickness, weight variation, drug content, surface pH, swelling index, bioadhesive force and in vitro drug release. RESULTS: The FTIR and DSC studies showed no evidence of interactions between drug, polymers and excipients. The P-XRD study revealed that crystallinity of TM remain unchanged in optimized formulation tablet. Formulation F9 achieves an in vitro drug release of 98.967% ± 0.28 at 8 h and a bioadhesive force of 0.088 N ± 0.01211. CONCLUSION: We successfully developed buccal tablet formulations of TM and describe a non-Fickian-type anomalous transport as the release mechanism.


Subject(s)
Timolol/administration & dosage , Acrylates/chemistry , Adhesiveness , Administration, Buccal , Alginates/chemistry , Biological Availability , Calorimetry, Differential Scanning , Chemistry, Pharmaceutical , Drug Delivery Systems , Drug Stability , Excipients/chemistry , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Humans , Powder Diffraction , Spectroscopy, Fourier Transform Infrared , Tablets , Timolol/pharmacokinetics
15.
J Bacteriol ; 191(14): 4624-32, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19447909

ABSTRACT

Pseudomonas putida CBB5 was isolated from soil by enrichment on caffeine. This strain used not only caffeine, theobromine, paraxanthine, and 7-methylxanthine as sole carbon and nitrogen sources but also theophylline and 3-methylxanthine. Analyses of metabolites in spent media and resting cell suspensions confirmed that CBB5 initially N demethylated theophylline via a hitherto unreported pathway to 1- and 3-methylxanthines. NAD(P)H-dependent conversion of theophylline to 1- and 3-methylxanthines was also detected in the crude cell extracts of theophylline-grown CBB5. 1-Methylxanthine and 3-methylxanthine were subsequently N demethylated to xanthine. CBB5 also oxidized theophylline and 1- and 3-methylxanthines to 1,3-dimethyluric acid and 1- and 3-methyluric acids, respectively. However, these methyluric acids were not metabolized further. A broad-substrate-range xanthine-oxidizing enzyme was responsible for the formation of these methyluric acids. In contrast, CBB5 metabolized caffeine to theobromine (major metabolite) and paraxanthine (minor metabolite). These dimethylxanthines were further N demethylated to xanthine via 7-methylxanthine. Theobromine-, paraxanthine-, and 7-methylxanthine-grown cells also metabolized all of the methylxanthines mentioned above via the same pathway. Thus, the theophylline and caffeine N-demethylation pathways converged at xanthine via different methylxanthine intermediates. Xanthine was eventually oxidized to uric acid. Enzymes involved in theophylline and caffeine degradation were coexpressed when CBB5 was grown on theophylline or on caffeine or its metabolites. However, 3-methylxanthine-grown CBB5 cells did not metabolize caffeine, whereas theophylline was metabolized at much reduced levels to only methyluric acids. To our knowledge, this is the first report of theophylline N demethylation and coexpression of distinct pathways for caffeine and theophylline degradation in bacteria.


Subject(s)
Caffeine/metabolism , Gene Expression , Metabolic Networks and Pathways/genetics , Pseudomonas putida/metabolism , Theophylline/metabolism , Theobromine/metabolism , Uric Acid/analogs & derivatives , Uric Acid/metabolism , Xanthine/metabolism , Xanthines/metabolism
16.
J Bacteriol ; 190(2): 772-6, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17981969

ABSTRACT

A unique heterotrimeric caffeine dehydrogenase was purified from Pseudomonas sp. strain CBB1. This enzyme oxidized caffeine to trimethyluric acid stoichiometrically and hydrolytically, without producing hydrogen peroxide. The enzyme was not NAD(P)(+) dependent; coenzyme Q(0) was the preferred electron acceptor. The enzyme was specific for caffeine and theobromine and showed no activity with xanthine.


Subject(s)
Bacterial Proteins/metabolism , Caffeine/metabolism , Oxidoreductases/metabolism , Pseudomonas/enzymology , Uric Acid/analogs & derivatives , Bacterial Proteins/chemistry , Bacterial Proteins/isolation & purification , Oxidoreductases/chemistry , Oxidoreductases/isolation & purification , Substrate Specificity , Theobromine/metabolism , Ubiquinone/metabolism , Uric Acid/metabolism , Xanthine/metabolism
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