In vitro Sun Protection Factors (SPFs) of Sunscreen and Skin Irritability / 대한피부과학회지

BACKGROUND: Use of suncreen is strongly recommended to prevent the harmful effect by ultraviolet (UV) ray, and new diverse synthetic chemicals have been screened and put forward as effective UV filters. However, the most important aspect of developing a novel UV filter is safety. OBJECTIVE: This study aimed to find out if there was any correlation between a high in vitro SPF (Sun Protection Factor) index and skin irritation by using standardized formulations containing organic or inorganic, active sunscreen ingredients. METHODS: HRIPT (Human repeated insult patch test) was conducted on with fifty subjects (male to female ratio as 3: 2, average age was 21.6+/-2.9 years), and in vitro SPFs of sunscreen formulations were measured. Patch tested UV filters (UVA, UVB, and physical blockers) were butyl methoxy dibenzoyl methane (BMDM 2%, 5%), benzophenone-3 (2%, 5%), homosalate (10%, 20%), octyl methoxy cinnamate (10%, 20%), octyl salicylate (5%, 10%), octocrylene (10%, 20%), zinc oxide (10%, 20%)and titanium dioxide (10%, 20%). Skin bioengineering measurements for capacitance, erythema, laser doppler blood flow were carried out before and after HRIPT to compare the subjective observation errors of the conventional scoring system of skin irritation (ICDRG standard). To explore any photoirritability, phototoxicity or photoallergy, individual UV filters were photopatch tested with higher concentrations (5%, 20%) than those of usual photopatch sunscreen test series RESULTS: The range of in vitro SPF revealed from 3.6 to 52.8. A doubtful, rather transient, weak erythema (+0.5) was noted in eight subjects, though the apparent skin irritation reaction can be estimated at over +1 by ICDRG guideline was not found during the HRIPT. The weak erythemas were observed at 20% homosalate, 10% octyl salicylate, 5% octyl salicylate, 20% octyl methoxycinnamate, 10% octyl methoxycinnamate, 10% octocrylene, 20% octocrylene, 5% BMDM, respectively in frequency, thus UVB filters of high concentration were related to weak irritation. Nosignificant differences in the measured skin bioengineering parameters were detected between before and after the HRIPT. Photopatch test failed to find any photoirritability and photoallergy. CONCLUSION: Skin irritability due to high in vitro SPFs appeared to be minimal or remained within the safety margin. However, a weak irritation was suspected from the organic UVB filters under the higher concentration range than its recommended range by regulatory guidelines. As for the newly developed, diverse formulations of multi-organic UV filters claiming high SPFs, dermatologists could consider the potential irritation reactions when it is preferentially used within a population.

Chromosome Aberrations and Sister-chromatid Exchanges in Workers Exposed to Mixed-organic Solvents in Shoe-making Workshops

Chromosome aberrations and sister chromatid exchanges (SCEs) in lymphocytes of peropheral blood as an indicator which could evaluate the effects of mutagenicity after in human exposure to mixed-organic solvents were measured. This study was conducted using 33 shoe making workers occupationally exposed to organic solvents and 33 unexposed control. The results were as follows. 1. The mean air concentrations of n-hexane, toluene, ethyl acetate in working environment were 9.8-14.8, 31.7-45.4 and 4.4-7.6 ppm, respectively. 2. The frequencies of chromosome aberration in exposed workers to mixed-organic solvents and the unexposed were 1.12+/-1.24, 0.36+/-0.70, respectively and their differences were statistically significant (p<0.01). However, the SCE frequencies were not statistically significant between the both groups. 3. The frequencies of chromosome aberration and SCE were no statistically differences by sex, smoking and drinking.

Genetic Toxicity of Ochratoxin A in Chinese Hamster Lung and VERO Cells, ddY Mice, and Drosophila melanogaster

Ochratoxin A is a natural contaminant of mouldy food and feed, which is produced by Penicillium and Aspergillus, and is suspected of being one of the etiological agents responsible for Balkan endemic nephropathy and the associated urinary tract tumors. For evaluation of the mutagenicity of ochratoxin A, we performed in vitro chromosome aberration tests using Chinese hamster lung fibroblast cells (CHL cells) and monkey kidney cells (VERO cells), in vivo micronueleus tests using ddY mouse bone marrow cells and somatic mutation and recombination tests (SMART) using Drosophila melanogaster. The results of chromosome aberration tests in CHL cells showed no incidence of increased structural and numerical aberrations regardless of metabolic activation, while in VERO cells treated with 2.0, 1.0, 0.5, 0.3 ug/ml of ochratoxin A showed significant increase of structural aberrations without metabolic activation. Aspartame and-phenylalanine, structural analogs of ochratoxin A, didn't affect the chromosome aberrations induced by ochratoxin A. The in vivo induction of micronucleated polychromatic erythrocytes were measured in bone marrows of ddY mice treated with 10.0, 5.0, 2.5mg/kg/10ml of ochratoxin A through intraperitoneal route once. At 24 and 48 hours after treatment, ochratoxin A didn't induce micronuclei in bone marrows of ddY mice. And at the concentration of 40, 20, 10 ug/ml of ochratoxin A, which was administered by feeding to larvae of Drosophila melanogaster, showed no incidence of increased multiple wing hairs and flares. Summarizing all results, we concluded that ochratoxin A is a kidney cell specific direct genotoxicant.