Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
1.
J Cosmet Dermatol ; 19(2): 466-472, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31125171

ABSTRACT

BACKGROUND: All over the world, people face the same skin problems. However, their skin characteristics are different. Thus, it is a challenge to prescribe treatments that will be effective on different skin types. Therefore, it is very important to consider the skin biology when indicating a dermocosmetic treatment. OBJECTIVES: To assess skin biophysical parameters in French and Brazilian subjects and to verify the efficacy of four dermocosmetic treatments in these populations. METHODS: Five test areas were defined on each volar forearm of the eighteen Brazilian and eighteen French participants using a randomized design. Biophysical measurements in terms of skin hydration, skin barrier function, skin brightness, and skin viscoelasticity were performed before and after 60 minutes of treatment. RESULTS: Skin biophysical differences between populations were found. French skin has been shown to be more hydrated regarding epidermal mechanic properties and stratum corneum water content and more radiant when compared with Brazilian skin. However, it showed more signs of cutaneous aging and fatigue effects on skin. The Brazilian skin showed better skin barrier function. In addition, the treatments were effective in both populations. CONCLUSIONS: Despite the differences found in French and Brazilian skin, the proposed dermocosmetic treatments showed effective in both populations.


Subject(s)
Bleaching Agents/administration & dosage , Cosmetic Techniques , Skin Aging/drug effects , Skin Cream/administration & dosage , Skin/drug effects , Adult , Brazil , Elasticity/drug effects , Elasticity/physiology , France , Geography , Humans , Skin/chemistry , Skin Aging/physiology , Treatment Outcome , Viscosity/drug effects , Water Loss, Insensible/drug effects , Water Loss, Insensible/physiology , Young Adult
2.
São José dos Campos; s.n; 2020. 143 p. il., graf., tab..
Thesis in Portuguese | BBO - Dentistry | ID: biblio-1151425

ABSTRACT

Esse trabalho objetivou através de um ensaio clínico de acompanhamento de 7 dias comparar o clareamento por 2 técnicas em jovens e adultos, avaliando a sensibilidade dental, eficácia e impactos na qualidade de vida, e por meio de uma revisão sistemática avaliar a segurança e eficácia do clareamento caseiro em comparação as demais técnicas em adolescentes. No estudo clínico 80 participantes constituíram 2 grupos: Jovens ­ JOV (14 a 20 anos) e adultos ­ ADU (40 a 60 anos) onde foram divididos aleatoriamente de acordo com a técnica clareadora: caseiro (CAS) e de consultório (CONS). A sensibilidade foi acompanhada com auxílio da Escala Visual Análoga (EVA) e Escala de Classificação Numérica (ECN), as alterações de cores através das escalas VITA Bleachedguide (VB), VITA Clássica (VC) e por fotografias e o impacto na qualidade de vida foi mensurado pelo questionário OHIP-14. Para análise estatística dos dados foram utilizados os testes ANOVA 2 fatores e de medidas repetidas, comparações múltiplas de Tukey, KruskalWallis e Friedman. Os resultados mostraram que pela EVA os grupos CAS apresentaram menor sensibilidade que os CONS e que todos grupos apresentaram sensibilidade após 7 dias igual a inicial, pela ECN os grupos CONS apresentaram a sensibilidade após 2ª sessão e 7 dias superior à inicial e após 1ª sessão. As escalas VB e VC mostraram alterações de cores após 2ª sessão/semana e 7dias superior que após 1ª sessão/semana e apenas a escala VB detectou um clareamento após 7 dias dos JOV superior aos ADU. Pela análise de fotografias os JOV apresentaram um maior clareamento que os ADU. Não houve entre os grupos diferenças estatísticas para impactos na qualidade de vida. Pode-se concluir que a sensibilidade final para todos os grupos foi igual à sensibilidade inicial, que os JOV apresentaram um maior clareamento e que não houve diferenças no impacto na qualidade de vida. Na revisão sistemática, com base na pergunta de pesquisa e estratégia PICO (P): Pacientes adolescentes com dentes escurecidos (I) Intervenção: Clareamento dental caseiro (C) Comparação: demais técnicas de clareamento dental; (O) Desfecho: Sensibilidade dental, injúrias aos tecidos moles e eficácia clareadora, foi realizada uma busca com estratégia definida nas principais bases de dados eletrônicas. Foram incluídos ensaios clínicos que responderam a pergunta de pesquisa, e a extração de dados e análise de risco de viés foram realizada. Três artigos foram selecionados e estes comparavam clareamento caseiro com moldeiras x fitas. Para a alteração de cor, não foram encontradas diferenças entre os tratamentos, porém foi observada uma alta heterogeneidade Adicionalmente uma meta-regressão que mostrou que a concentração do peróxido de hidrogênio (fitas) afeta significativamente a alteração de cor, explicando 100% da heterogeneidade para este desfecho. A incidência de sensibilidade e injúrias aos tecidos moles não foi influenciada pela técnica clareadora e os estudos apresentaram uma baixa heterogeneidade. Esta revisão pode concluir que os resultados obtidos sugerem que não existem diferenças entre as técnicas Adicionalmente uma meta-regressão que mostrou que a concentração do peróxido de hidrogênio (fitas) afeta significativamente a alteração de cor, explicando 100% da heterogeneidade para este desfecho. A incidência de sensibilidade e injúrias aos tecidos moles não foi influenciada pela técnica clareadora e os estudos apresentaram uma baixa heterogeneidade. Esta revisão pode concluir que os resultados obtidos sugerem que não existem diferenças entre as técnicas Adicionalmente uma meta-regressão que mostrou que a concentração do peróxido de hidrogênio (fitas) afeta significativamente a alteração de cor, explicando 100% da heterogeneidade para este desfecho. A incidência de sensibilidade e injúrias aos tecidos moles não foi influenciada pela técnica clareadora e os estudos apresentaram uma baixa heterogeneidade. Esta revisão pode concluir que os resultados obtidos sugerem que não existem diferenças entre as técnicas clareadoras (moldeiras x fitas) para à eficácia clareadora e segurança em jovens(AU)


This study aimed, comparing 2 whitening techniques in young and adults people, assessing dental sensitivity, efficacy and impacts on quality of life by a 7-day followup clinical trial, and through a systematic review to evaluate the safety and efficacy of the home bleaching compared to other techniques in adolescents. In the clinical trial 80 participants constituted 2 groups: Young - YOUN (14 to 20 years old) and adults - ADU (40 to 60 years old) where they were randomly divided according to the whitening technique: at home (HOM) and in office (OFFI). Sensitivity was monitored with the Visual Analog Scale (VAS) and Numerical Rating Scale (NRS), the color changes through the VITA Bleachedguide (VB), VITA Classical (VC) shade guides, and by photographs and the impact on quality of life was measured by the OHIP-14 questionnaire. Statistical analyses were performed using the 2-way ANOVA and repeated measures ANOVA. For multiple comparisons, Tukey, Kruskal-Wallis and Friedman tests were used. The results showed that by VAS the HOM groups showed less sensitivity than the OFFI and that all groups showed sensitivity after 7 days equal to the initial, by NRS the OFFI groups showed the sensitivity after the second session and 7 days higher than the initial and after the first session. The VB and VC scales showed color changes after the second session/week and 7 days higher than after the first session/week, and only the VB scale detected a whitening after 7 days of the YOUN superior to the ADU. Through the analysis of photographs, the YOUN showed greater leaching than the ADU. There were no statistical differences between groups for impacts on quality of life. It can be concluded that the final sensitivity for all groups was equal to the initial sensitivity, that the YOUN showed greater whitening and that there were no differences in the impact on quality of life. In the systematic review, based on the research question and strategy PICO (P): Adolescent patients with darkened teeth (I) Intervention: Home tooth whitening (C) Comparison: other teeth whitening techniques; (O) Outcome: Dental sensitivity, injuries to soft tissues and whitening efficacy, a search was carried out with a defined strategy in the main electronic databases. Clinical trials that answered the research question were included, and data extraction and risk of bias analysis were performed. Three studies were selected and they compared home whitening with trays x strips. For the color change, no differences were found between treatments, but a high heterogeneity was observed. Additionally, a meta-regression that showed that the concentration of hydrogen peroxide (strips) significantly affects the color change, explaining 100% of the heterogeneity for this outcome. The incidence of sensitivity and injuries to soft tissues was not influenced by the bleaching technique and the studies showed low heterogeneity. This review concluded that the results obtained suggest that there are no differences between the whitening techniques (trays x strips) for whitening efficacy and safety in young people(AU)


Subject(s)
Tooth Bleaching/trends , Adolescent , Clinical Trial , Bleaching Agents/administration & dosage , Systematic Review
4.
J Dent Child (Chic) ; 84(1): 22-29, 2017 Jan 15.
Article in English | MEDLINE | ID: mdl-28387186

ABSTRACT

PURPOSE: The purpose of this study was to evaluate, in vitro, the efficacy of 10 percent carbamide peroxide used as an intracoronal bleaching agent in blood-stained primary teeth. METHODS: Thirty extracted primary canines were stained using rabbit blood and randomly divided into two groups of 15 teeth each. Stained teeth in the test group were bleached intracoronally using 10 percent carbamide peroxide for 21 days. The bleaching agent was replaced at days seven and 14. The control group was not subjected to bleaching, and a cotton pellet damped with distilled water was placed in the pulp chamber. Shade alteration from the prestaining value was evaluated using a VITA Easyshade spectrophotometer at days zero, seven, 14, and 21. RESULTS: All specimens in the test group returned to the initial baseline shade, with no significant differences from the prestaining values (P=0.097). Teeth in the control group did not undergo any shade alteration after staining, with no significant differences noted from the prestaining values (P<0.001). CONCLUSIONS: Intracoronal bleaching using 10 percent carbamide peroxide is an effective approach for whitening discolored extracted primary teeth.


Subject(s)
Bleaching Agents/administration & dosage , Peroxides/administration & dosage , Tooth Bleaching/methods , Tooth, Deciduous/drug effects , Tooth, Nonvital , Urea/analogs & derivatives , Animals , Bicuspid/drug effects , Bleaching Agents/therapeutic use , Blood Stains , Carbamide Peroxide , Color , Dental Pulp Cavity/drug effects , Humans , Peroxides/therapeutic use , Rabbits , Time Factors , Tooth Cervix , Tooth Discoloration/drug therapy , Urea/administration & dosage , Urea/therapeutic use
6.
Clin Oral Investig ; 19(6): 1437-42, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25416638

ABSTRACT

OBJECTIVES: To investigate the whitening effects of different bleaching agents on teeth discoloured by different antibiotic combinations of ciprofloxacin and metronidazole with minocycline, doxycycline, amoxicillin or cefaclor. MATERIALS AND METHODS: Forty extracted bovine incisors were collected and discoloured with triple antibiotic pastes (TAP) with minocycline, doxycycline, amoxicillin and cefaclor throughout 30 days. The specimens were then randomly divided into two subgroups and each group received different bleaching materials: 35% hydrogen peroxide and sodium perborate. Spectrophotometric measurements were obtained on the buccal surfaces of the crown, firstly in the beginning, then on the 4th, 8th and 12th days after the placement of the bleaching materials. The acceptability threshold was set to 3.5. The ∆E values were calculated and the data was analysed using the repeated measures analysis of variance (P = .05). RESULTS: All the test groups induced colour changes exceeding the acceptability threshold 30 days after the antibiotic pastes were placed. The 35% hydrogen peroxide was more effective than sodium perborate in the whitening of discoloured teeth by antibiotic pastes (P = .001). The whitening effect after the 8th and 12th days was significantly more than after 4 days of treatment (P <.001). The discolouration caused by the TAP with minocycline and cefaclor showed greater whitening compared to the TAP with doxycycline and amoxicillin groups (P <.05). CONCLUSIONS: The whitening treatment effect of 35% hydrogen peroxide on teeth discoloured by antibiotic pastes seems to have significantly outperformed the sodium perborate treatment. Both bleaching agents were allowed to bleach the teeth gradually each day and the effects on the 8th and 12th days were superior to the one on the 4th day. CLINICAL RELEVANCE: The use of 35% hydrogen peroxide could be advantageous to bleach the teeth discoloured with antibiotic pastes compared to sodium perborate.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Bleaching Agents/administration & dosage , Hydrogen Peroxide/administration & dosage , Tooth Bleaching/methods , Tooth Discoloration/chemically induced , Tooth Discoloration/drug therapy , Animals , Borates/administration & dosage , Cattle , Composite Resins , In Vitro Techniques , Iridescence
7.
J Travel Med ; 21(4): 282-7, 2014.
Article in English | MEDLINE | ID: mdl-24612323

ABSTRACT

BACKGROUND: Using skin-lightening compounds for a cosmetic purpose that are normally restricted to medical use or forbidden has become a world-wide practice. Complications are numerous. Immigrant communities often import their practice from their original country. METHODS: A review of the literature on the subject of complications of cosmetic skin-bleaching, with special focus on data concerning immigrants originating from highly endemic countries, was conducted. RESULTS: Complications of cosmetic skin-bleaching are common, involving mainly the skin although some general complications are also reported with a growing incidence. CONCLUSION: The high frequency of this practice, added to the frequency of various complications, suggests it might be considered as a genuine public health problem currently.


Subject(s)
Bleaching Agents/adverse effects , Cosmetics/adverse effects , Emigrants and Immigrants/statistics & numerical data , Skin Diseases/chemically induced , Skin Pigmentation/drug effects , Acne Vulgaris/chemically induced , Bleaching Agents/administration & dosage , Cosmetics/administration & dosage , Humans , Ochronosis/chemically induced , Skin Diseases/epidemiology
8.
Cancer Genomics Proteomics ; 10(5): 209-15, 2013.
Article in English | MEDLINE | ID: mdl-24136973

ABSTRACT

AIM: To analyze the genotoxic effect of two hydrogen peroxide-containing bleaching products on oral mucosal cells. MATERIALS AND METHODS: The research was conducted on 22 individuals divided into two groups. Group 1 used ZOOM2 and group 2 the Opalescence BOOST bleaching agent. Specimens of the gingival and the upper lip mucosa were obtained before, immediately after, and 72 h after the bleaching procedure and were analyzed using a micronucleus test. RESULTS: Seventy-two hours after bleaching treatment with BOOST, samples collected from the oral mucosa exhibited a statistically significant increase of all genotoxicity markers, with large effect sizes (Cohen's d>0.8) observed in the total number of micronuclei (MN), number of cells with 3+ MN, karyolysis and bi-nuclear cells. ZOOM2 treatment showed a significant increase, with medium-to-large effect sizes, in the number of cells with 1 MN, karyolysis, nuclear buds and bi-nuclear cells. CONCLUSION: Both preparations demonstrated potential genotoxic effects.


Subject(s)
Bleaching Agents/adverse effects , Mouth Mucosa/drug effects , Tooth Bleaching/adverse effects , Adolescent , Adult , Bleaching Agents/administration & dosage , Female , Humans , Hydrogen Peroxide/administration & dosage , Hydrogen Peroxide/adverse effects , Male , Young Adult
9.
J Dairy Sci ; 96(4): 2035-2047, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23415538

ABSTRACT

The goals of this study were to determine if adding annatto color to milk or applying a bleaching process to whey or microfiltration (MF) permeate influenced ultrafiltration (UF) flux, diafiltration (DF) flux, or membrane fouling during production of 80% whey protein concentrate (WPC80) or 80% serum protein concentrate (SPC80). Separated Cheddar cheese whey (18 vats using 900 kg of whole milk each) and MF permeate of skim milk (18 processing runs using 800 kg of skim milk each) were produced to make WPC80 and SPC80, respectively. The 6 treatments, replicated 3 times each, that constituted the 18 processing runs within either whey or MF permeate UF were as follows: (1) no annatto; (2) no annatto+benzoyl peroxide (BPO); (3) no annatto+hydrogen peroxide (H2O2); (4) annatto; (5) annatto+BPO; and (6) annatto+H2O2. Approximately 700 kg of whey or 530 kg of MF permeate from each treatment were heated to 50°C and processed in 2 stages (UF and DF) with the UF system in batch recirculation mode using a polyethersulfone spiral-wound UF membrane with a molecular weight cutoff of 10,000 Da. Addition of annatto color had no effect on UF or DF flux. The processes of bleaching whey or MF permeate with or without added color improved flux during processing. Bleaching with H2O2 usually produced higher flux than bleaching with BPO. Bleaching with BPO increased WPC80 flux to a greater extent than it did SPC80 flux. Though no differences in mean flux were observed for a common bleaching treatment between the WPC80 and SPC80 production processes during the UF stage, mean flux during WPC80 DF was higher than mean flux during SPC80 DF for each bleaching treatment. Water flux values before and after processing were used to calculate a fouling coefficient that demonstrated differences in fouling which were consistent with flux differences among treatments. In both processes, bleaching with H2O2 led to the largest reduction in fouling. No effect of annatto on fouling was observed. The reasons for flux enhancement associated with bleaching treatments are unclear.


Subject(s)
Bleaching Agents/administration & dosage , Blood Proteins/isolation & purification , Carotenoids/administration & dosage , Milk Proteins/isolation & purification , Plant Extracts/administration & dosage , Ultrafiltration/methods , Animals , Benzoyl Peroxide/administration & dosage , Bixaceae , Blood Proteins/chemistry , Cheese/analysis , Food Preservation , Food Technology/methods , Hydrogen Peroxide/administration & dosage , Milk/chemistry , Milk Proteins/chemistry , Whey Proteins
10.
J Biomed Opt ; 17(8): 087003-1, 2012 Aug.
Article in English | MEDLINE | ID: mdl-23224202

ABSTRACT

Application of low concentration acetic acid solution to various types of human epithelia, in vivo, is a well-established technique for the visual identification of neoplastic and potential precancerous lesions, especially in the cervix. An acetic acid application produces a transient whitening effect associated with the aforementioned lesions (acetowhite effect). In this article, a simple semi-empirical tissue reflectance model is presented, which describes the acetowhite effect in terms of the tissue's optical properties and layered structure. The model successfully describes data available in the literature, explains basic characteristics of the acetowhite effect, and can serve as the basis for the development of more accurate and reliable noninvasive diagnostic methodologies for precancerous epithelial lesions.


Subject(s)
Acetic Acid/administration & dosage , Bleaching Agents/administration & dosage , Epithelium/anatomy & histology , Epithelium/physiology , Models, Biological , Animals , Computer Simulation , Epithelium/drug effects , Humans , Light , Scattering, Radiation
11.
J Hosp Infect ; 82(4): 234-42, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23103245

ABSTRACT

BACKGROUND: Vancomycin-resistant enterococcus (VRE) colonization and infection have increased at our hospital, despite adherence to standard VRE control guidelines. AIM: We implemented a multi-modal, hospital-wide improvement programme including a bleach-based cleaning-disinfection programme ('Bleach-Clean'). VRE colonization, infection and environmental contamination were compared pre and post implementation. METHODS: The programme included a new product (sodium hypochlorite 1000 ppm + detergent), standardized cleaning-disinfection practices, employment of cleaning supervisors, and modified protocols to rely on alcohol-based hand hygiene and sleeveless aprons instead of long-sleeved gowns and gloves. VRE was isolated using chromogenic agar and/or routine laboratory methods. Outcomes were assessed during the 6 months pre and 12 months post implementation, including proportions (per 100 patients screened) of VRE colonization in high-risk wards (HRWs: intensive care, liver transplant, renal, haematology/oncology); proportions of environmental contamination; and episodes of VRE bacteraemia throughout the entire hospital. FINDINGS: Significant reductions in newly recognized VRE colonizations (208/1948 patients screened vs 324/4035, a 24.8% reduction, P = 0.001) and environmental contamination (66.4% reduction, P = 0.012) were observed, but the proportion of patients colonized on admission was stable. The total burden of inpatients with VRE in the HRWs also declined (median percentage of colonized inpatients per week, 19.4% vs 17.3%, P = 0.016). Hospital-wide VRE bacteraemia declined from 14/2935 patients investigated to 5/6194 (83.1% reduction; P < 0.001), but there was no change in vancomycin-susceptible enterococcal bacteraemia (P = 0.54). CONCLUSION: The Bleach-Clean programme was associated with marked reductions in new VRE colonizations in high-risk patients, and VRE bacteraemia across the entire hospital. These findings have important implications for VRE control in endemic healthcare settings.


Subject(s)
Bleaching Agents/administration & dosage , Carrier State/epidemiology , Cross Infection/epidemiology , Disinfection/methods , Enterococcus/isolation & purification , Gram-Positive Bacterial Infections/epidemiology , Vancomycin Resistance , Carrier State/microbiology , Carrier State/prevention & control , Cross Infection/microbiology , Cross Infection/prevention & control , Disinfectants/administration & dosage , Enterococcus/drug effects , Gram-Positive Bacterial Infections/microbiology , Gram-Positive Bacterial Infections/prevention & control , Humans , Incidence , Sodium Hypochlorite/administration & dosage
12.
J Endod ; 38(10): 1395-8, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22980186

ABSTRACT

INTRODUCTION: The aim of this study was to compare in vitro the tissue-dissolution properties of 5% and 10% calcium hypochlorite (Ca(OCl)(2)) with two concentrations (1.36% and 4.65%) of proprietary sodium hypochlorite (NaOCl) on bovine muscle tissue. METHODS: The available chlorine concentration of each solution was determined using iodometric titration. Tissue specimens from bovine muscle were weight adjusted (50 ± 5 mg). Ten tissue specimens in each group were immersed in 5 mL each test solution, removed after 5 minutes, blotted dry, and weighed. The process was repeated every 5 minutes with a fresh 5-mL aliquot of the test solution for 60 minutes or until complete tissue dissolution, whichever was quickest. The percentage weight loss of the specimens was calculated over the experimental period. RESULTS: Available chlorine concentrations of the irrigants ranged from 1.36% to 4.65%. All solutions dissolved tissue completely after 60 minutes except 5% Ca(OCl)(2) (99.4% dissolution). Between the 35- and 60-minute test readings, there were no significant differences between the solutions. Chlorax (4.65% NaOCl) (Cerkamed Group, Nisko, Poland) dissolved tissue quicker during the first 35 minutes (P < .05). In this period, the weight loss with 10% Ca(OCl)(2) differed from Chlorax at all time intervals except at 5 and 35 minutes (P < .05); 5% Ca(OCl)(2) showed no significant differences with 10% Ca(OCl)(2) and Tesco bleach (1.36% NaOCl) (Tesco Stores Ltd, Chestnut, UK) in the first 35 minutes except at the 5-minute measurement. CONCLUSIONS: Within the limitations of this study, Chlorax (4.65% NaOCl) dissolved tissue faster than the Ca(OCl)(2) solutions and Tesco thin bleach (1.36% NaOCl) over the first 35 minutes, but there were no significant differences among the solutions thereafter.


Subject(s)
Calcium Compounds/administration & dosage , Chlorine/pharmacology , Muscles/drug effects , Root Canal Irrigants/administration & dosage , Sodium Hypochlorite/administration & dosage , Animals , Bleaching Agents/administration & dosage , Bleaching Agents/pharmacology , Cattle , Chlorine/administration & dosage , Dose-Response Relationship, Drug , Solvents/administration & dosage , Solvents/pharmacology , Time Factors
13.
Hum Exp Toxicol ; 31(6): 637-9, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22297700

ABSTRACT

Sodium hypochlorite (NaClO) is used extensively as a disinfectant or bleaching agent. Most studies describe ingestion or inhalation route of this product with rare complication and fatalities. Despite global daily exposures, data about bleach injection is limited. Here we report intentional infusion of 20 mL, sodium hypochlorite 5% diluted in 500 mL normal saline 1.5 h prior admission. Clinical manifestation included local pain and edema. There were no laboratory abnormalities in the patient. Doppler sonography revealed thrombosis in superficial (antecubital and basilic) veins. Limb elevation, warm compress, and ibuprofen relived pain and edema after 3 days.


Subject(s)
Bleaching Agents/toxicity , Disinfectants/toxicity , Sodium Hypochlorite/toxicity , Venous Thrombosis/chemically induced , Adult , Bleaching Agents/administration & dosage , Disinfectants/administration & dosage , Humans , Injections, Intravenous , Male , Sodium Hypochlorite/administration & dosage , Suicide, Attempted
15.
Melanoma Res ; 21(2): 115-26, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21317816

ABSTRACT

Skin depigmentation represents a well-established treatment for extensive vitiligo and may likewise be suited to prevent tumor recurrences and as a prophylactic treatment of familial melanoma, as common bleaching agents are cytotoxic to melanocytes. Effective melanoma prevention requires a bleaching agent-induced loss of exposed melanocytes supported by an immune response to distant pigment cells. Studies on human explant cultures treated with depigmenting agents such as 4-tertiary butyl phenol (4-TBP) or monobenzyl ether of hydroquinone (MBEH) showed a significant increase in the migration of Langerhans cells toward the dermis only upon treatment with MBEH, thus suggesting selective elicitation of an immune response. To assess the depigmenting potential of bleaching agents in vivo, 4-TBP and MBEH were topically applied to C57BL/6 wild type as well as k14-SCF transgenic, epidermally pigmented mice. MBEH-induced significant skin depigmentation in both strains was not observed upon treatment with 4-TBP. Cytokine expression patterns in skin treated with MBEH support activation of a Th1-mediated immune response corresponding to an influx of T cells and macrophages. Importantly, despite insensitivity of tumor cells to MBEH-induced cytotoxicity, significantly retarded tumor growth was observed in B16 challenged k14-SCF mice pretreated with MBEH, likely due to an abundance of cytotoxic T cells accompanied by an increased expression of Th1 and Th17 cytokines. These data support the use of MBEH as a prophylactic treatment for melanoma.


Subject(s)
Melanoma/drug therapy , Phenols/administration & dosage , Skin Neoplasms/drug therapy , Administration, Topical , Animals , Bleaching Agents/administration & dosage , Cell Line, Tumor , Epidermis/drug effects , Epidermis/pathology , Humans , Langerhans Cells/drug effects , Langerhans Cells/pathology , Melanoma/pathology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Skin Neoplasms/pathology
16.
Polim Med ; 41(4): 17-25, 2011.
Article in Polish | MEDLINE | ID: mdl-22332322

ABSTRACT

An attempt was made to produce and test, according to the guidelines of Polish Pharmacopeia VIII, new prescriptions of hydrogels which could be applied in the treatment of skin diseases associated with hyperpigmentation. Hydrogel formulations containing a substance of skin-whitening activity (arbutin) and glycol plant extract was produced on Carbopol Ultrez 10 base. Two glycol plant extracts of confirmed beneficial effect on skin were selected: an extract of ginkgo leaves and of rosemary. For comparative purposes also preparations with arbutin were produced in which propylene glycol was introduced instead of glycol plant extracts. The assumption of the carried out study was to investigate physicochemical properties of model formulations, estimation of arbutin pharmaceutical availability from the suggested formulations and the assessment of the effect of glycol plant extract components on the process of arbutin diffusion from the produced hydrogel formulations. The formulation viscosity parameters were determined using cone-plate digital rheometer. Gravimetric method was applied to estimate the kinetics of volatile components from the preparations. Potentiometric method was used to measure pH. The rate of arbutin release through a semipermeable membrane to the acceptor fluid was tested in vitro. Spectrophotometric method was used for the determination of the quantity of the released therapeutic substance at defined time intervals. All the proposed formulations are viscoelastic systems having yield stress. There is a strict dependence between rheological properties characterizing the tested hydrogels and the quantity of the arbutin released from them. The process of arbutin release to the acceptor fluid through a semipermeable membrane was most effective from the formulation containing glycol extract of ginkgo (F1A+M).


Subject(s)
Arbutin/chemistry , Bleaching Agents/chemistry , Hydrogels/chemistry , Models, Chemical , Phytotherapy , Plant Extracts/chemistry , Skin Pigmentation/drug effects , Administration, Topical , Arbutin/administration & dosage , Bleaching Agents/administration & dosage , Chemistry, Pharmaceutical , Ginkgo biloba , Hydrogels/administration & dosage , Hydrogen-Ion Concentration , Oils, Volatile , Plant Extracts/administration & dosage , Rheology , Rosmarinus
17.
Biosci Biotechnol Biochem ; 74(11): 2253-8, 2010.
Article in English | MEDLINE | ID: mdl-21071833

ABSTRACT

Measurement of the melanin content by using B16 melanoma cells is generally applied to find novel skin-whitening agents. However, this measurement method using B16 melanoma cells has such disadvantages, as the time taken, its sensitivity, and troublesomeness. We therefore attempted in the present study to establish a reporter assay system by measuring the tyrosinase promoter activity to use for convenient, high-throughput screening of new melanogenesis inhibitors. We first confirmed the validity of this reporter assay system by using such known skin-whitening agents, as arbutin, sulforaphane, and theaflavin 3,3'-digallate. We then compared the effect of 56 compounds on the tyrosinase promoter activity to test this reporter assay system. Carnosol, and rottlerin strongly inhibited the tyrosinase promoter activity. Moreover, carnosol and rottlerin decreased melanin synthesis and tyrosinase expression in a dose-dependent manner when using B16 melanoma cells. These results indicate this new luciferase reported assay system to be an effective and convenient method for screening potential skin-whitening compounds.


Subject(s)
Administration, Cutaneous , Bleaching Agents/administration & dosage , High-Throughput Screening Assays/methods , Skin Pigmentation/drug effects , Drug Evaluation, Preclinical/methods , Humans , Luciferases , Melanoma, Experimental , Monophenol Monooxygenase/genetics , Promoter Regions, Genetic
18.
J Eur Acad Dermatol Venereol ; 24(10): 1214-9, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20236376

ABSTRACT

BACKGROUND: Although the practice of bleaching is common worldwide, there are few studies that discuss knowledge, attitudes and practices towards bleaching. OBJECTIVE: The aim of this study was to explore the knowledge, attitudes and practices towards the usage of topical bleaching agents among women. METHODS: A self-administered questionnaire on the use of bleaching creams was distributed randomly to women attending the outpatient clinics at a university hospital in Saudi Arabia during 2008. RESULTS: Five hundred and nine of 620 women responded (82% response rate). All the participants had dark skin (skin type 4-5). The mean age was 29.22 ± 9 years. Of the participants, 38.9% (197/506) were current users of bleaching agents. Only 26.7% (106/397) of the respondents used bleaching agents for medical purposes to treat localized abnormal skin hyper-pigmentation; 20.8% (101/485) were ready to use any bleaching cream that gives fast results, even if the components were unknown. Of the respondents, 30% (152/509) used more than 100 g of bleaching creams monthly. These products were applied to the whole body in 7.3% of the cases. While 10.3% (28/271) continued applying the bleaching products during pregnancy, 20.8% (54/260) did so during lactation. No associations could be found between the various sociodemographic variables and differences in the attitude towards and practice of using bleaching creams. CONCLUSION: A major proportion of our sample respondents have overused and/or misused bleaching agents. This was regardless of age, income, education or marital status. There is a need to educate women about the possible risks.


Subject(s)
Bleaching Agents/adverse effects , Bleaching Agents/pharmacology , Health Knowledge, Attitudes, Practice , Skin Pigmentation/drug effects , Acne Vulgaris/epidemiology , Administration, Topical , Adolescent , Adult , Bleaching Agents/administration & dosage , Child , Cross-Sectional Studies , Data Collection , Female , Humans , Hypertrichosis/epidemiology , Middle Aged , Risk Factors , Saudi Arabia , Socioeconomic Factors , Telangiectasis/epidemiology , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL
...