Melatonin attenuates the detrimental effects of UVA irradiation in human dermal fibroblasts by suppressing oxidative damage and MAPK/AP-1 signal pathway in vitro.

BACKGROUND: People living in Mediterranean countries are mostly exposed to solar ultraviolet (UV) radiation that damages skin and results in photoaging which involves activation of epidermal growth factor receptor (EGFR) and downstream signal transduction through mitogen-activated protein kinases (MAPKs) in fibroblasts. Generation of reactive oxygen/nitrogen species by UV radiation is also critical for EGFR and MAPKs activation. MAPKs are responsible for activation of AP-1 subunits in the nucleus which induce matrix metalloproteinases. Melatonin, along with its metabolites, are known to be the most effective free radical scavenger and protective agent due to its ability to react with various radicals, lipophilic/hydrophilic structures. OBJECTIVES: In this study, we investigated the effects of melatonin on UVA-irradiated primary human dermal fibroblasts (HDFs) by following the alteration of molecules from cell membrane to the nucleus and oxidative/nitrosative damage status of the cells in a time-dependent manner which have not been clearly elucidated yet. METHODS: To mimic UVA dosage in Mediterranean countries, HDFs were exposed to UVA with sub-cytotoxic dosage (20 J/cm2 ) after pretreatment with melatonin (1 µmol/L) for 1 hour. Changes in the activation of the molecules and oxidative/nitrosative stress damage were analyzed at different time points. RESULTS: Our results clearly show that melatonin decreases UVA-induced oxidative/nitrosative stress damage in HDFs. It also suppresses phosphorylation of EGFR, activation of MAPK/AP-1 signal transduction pathway and production of matrix metalloproteinases in a time-dependent manner. CONCLUSION: Melatonin can be used as a protective agent for skin damage against intracellular detrimental effects of relatively high dosage of UVA irradiation.

Glycolic acid peels versus amino fruit acid peels for acne.

INTRODUCTION: Chemical exfoliation resulting in the reduction of keratotic plugs serves as a second-line treatment used as an adjunct to anti-acne agents. This study was designed to compare the therapeutic effects of glycolic acid (GA) peels and amino fruit acid (AFA) peels in patients with acne vulgaris. METHODS: In this single-blind, randomized, right-left comparison study, 24 patients received 12 serial peels (GA and AFA, at concentrations from the lowest to the highest) on the two halves of the face at 2-week intervals for 6 months. In addition, cutaneous tolerability assessments during the applications and the patient preference test between both peeling methods at the end of the study were performed. RESULTS: There was a statistically significant decrease in the number of non-inflamed lesions with GA following the first month and with AFA following the second month (p < 0.05). The decrease in the number of inflamed lesions was statistically significant with GA at the end of the fifth and sixth months and with AFA only at the end of the fifth month (p < 0.05). When the two applications were compared with each other, there was not a statistically significant difference in terms of non-inflamed and inflamed lesions (p > 0.05). During the application, it was observed that AFA peels caused fewer problems than GA peels did. AFA concentrations were increased more rapidly and more sessions were performed at the highest concentration of AFA. CONCLUSION: Based on the results of this study, we can state that both GA and AFA peels are efficacious for comedonal acne. And, compared to a GA peel, an AFA peel is less irritating and better tolerated.

Glycolic acid peels versus amino fruit acid peels in the treatment of melasma.

BACKGROUND: Chemical peels are becoming more popular as a treatment modality for melasma. OBJECTIVE: To compare the therapeutic effects of glycolic acid (GA) peels and amino fruit acid (AFA) peels in patients with melasma. METHODS: In this single-blind, randomized right-left comparison study, patients received 12 serial peels on the two halves of the face at 2-week intervals for 6 months. Clinical evaluation based on the modified Melasma Area and Severity Index (MASI) scores was performed at baseline and at 3 and 6 months. RESULTS: The modified MASI scores at 3 and 6 months in both application areas decreased significantly from baseline (p<.05). When the two applications were compared with each other, there was no statistically significant difference between GA and AFA in terms of regression of melasma (p>.05). During the application, it was observed that AFA peels caused fewer problems than GA peels did. CONCLUSIONS: Based on the results of this study, GA and AFA peels for melasma therapy were efficacious, but the AFA peel was found to be less irritating and was better tolerated.

Comparison of the effects of pulsed dye laser, pulsed dye laser + salicylic acid, and clobetasole propionate + salicylic acid on psoriatic plaques.

BACKGROUND: Studies show that pulsed dye laser (PDL) has some clinical benefits on psoriasis with a low clearance rate. In addition, it has been suggested that applying keratolytics before treatment might be helpful in PDL therapy. Topical corticosteroids remain the most commonly prescribed agents for psoriasis. OBJECTIVE: This study was designed to compare the efficacy of the PDL treatment with that of PDL treatment after salicylic acid on psoriatic plaques. The other goal of this study was to compare the efficacy of the PDL treatment with that of clobetasol propionate treatment. METHODS: Twenty-two patients with chronic, stable psoriatic plaques that involved less than 20% of their body were included in the study. Three similar-appearing psoriasis plaques in these patients were selected. Whereas the first plaque received only PDL, the second plaque received PDL after salicylic acid, and the third plaque received clobetasol propionate ointment and salicylic acid. Evaluation of the study plaques was carried out by the modified Psoriasis Area and Severity Index (mPASI) score and by measuring the area of the plaques. RESULTS: Of the 21 patients, 19 completed the study. Although the decrease in mPASI scores was determined to be maximum for clobetasol propionate + salicylic acid-treated plaques and minimum for only PDL-treated plaques, the decrease was statistically significant in all groups when compared with baseline (p < .003). At the 3- and 6-week evaluations, there was a statistically significant difference between clobetasol propionate + salicylic acid-treated plaques and the two PDL-treated plaques (p < .003); however, the difference observed at the 9-, 12-, and 15-week evaluations was statistically significant only between clobetasol propionate + salicylic acid-treated plaques and PDL-treated plaques (p < .003). When the baseline and 15-week evaluations were compared, there was no statistically significant increase in the mean lesion areas of clobetasol propionate + salicylic acid-treated psoriatic plaques (p > .003), but there was a statistically significant increase in the mean lesion areas of two PDL-treated psoriatic plaques (p < .003). CONCLUSION: The results of this study showed that the effect of PDL could be increased when salicylic acid was added to treatment, although there was no statistically significant difference between both treatment protocols. However, clobetasol propionate + salicylic acid treatment is more effective than both PDL and PDL + salicylic acid treatment.

Effects of calcipotriol cream and ointment, clobetasol cream and ointment and tretinoin cream on the erythemogenicity of UVB.

Various studies have shown the blocking effects of topical agents on UVB penetration, which can be used in combination with phototherapy. In this study, the photoprotective effects of 0.005% calcipotriol, 0.05% clobetasol-17-propionate, and 0.1% tretinoin, which can be used in combination with broad-band UVB, were investigated in an in vivo test. In a study group of 20 patients, phototests were performed to determine minimal erythema doses (MED) and the tests were repeated with thin (0.1 cc/25 cm2) and thick (0.3 cc/25 cm2) calcipotriol, clobetasol-17-propionate, and tretinoin in cream forms and sunscreen. After determining the MED, the test was repeated in another 20 patients with thin and thick calcipotriol and clobetasol-17-propionate in both cream and ointment forms and sunscreen. MED was increased with thin and thick applications of all agents. Moreover, the photoprotective effects of each agent increased with their thick applications compared with thin ones. The application of calcipotriol cream and ointment, clobetasol cream and ointment, and tretinoin cream, all of which can block UVB, is not recommended just before phototherapy.

Effects of topical petrolatum and salicylic acid upon skin photoreaction to UVA.

Various agents which can be used in combination can also interfere with phototherapy. In this study, the effects of topical petrolatum and 20% salicylic acid in petrolatum upon skin photoreaction to UVA were investigated, in an in vivo test. Minimal phototoxic dose (MPD) test was performed on 31 volunteers and the test was repeated with thin (0.1 cc/25 cm(2)) petrolatum, thick (0.3 cc/25 cm(2)) petrolatum, thin 20% salicylic acid in petrolatum, thick 20% salicylic acid in petrolatum and sunscreen. The effect of each agent on MPD was investigated. MPD was increased with thin and thick applications of all agents. Also, MPD was increased with 20% salicylic acid in petrolatum when compared with pure petrolatum, in the same thickness. The application of petrolatum and salicylic acid in petrolatum just before PUVA therapy is not recommended because of their blocking effects.