• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.413-420
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• 2016

Hydroxy acid has been used to enhance anti-aging and skin moisturization by peeling effect on the skin stratum corneum, and thus it has been widely used in topical products and cosmetic products. Among them, the effect that appears most effectively in a short period of time has been reported to be effected by the pH of the cosmetic formulations. However, there are many difficulties in use due to irritation caused by pH and concerns about side effects. The purpose of this study was to evaluate the effect of applying cosmetics with (1) varying concentrations, (2) types and (3) pH of hydroxy acid on human skin. 22 healthy adults were stained with DHA (dihydroxyacetone) and DC (dansyl chloride) on the forearm, and the skin exfoliation effect was measured after application of the test products. (1) The application of GA (glycolic acid) increased the desquamation by concentration dependent. (2) the test product prepared with neutral pH showed no exfoliation effect. In contrast, SA (salicylic acid) showed a statistically significant exfoliation effect at both acidic pH and neutral pH. (3) The neutral pH SA showed excellent exfoliation effect on bot DHA and DC stained stratum corneum. These results suggest that it is possible to manufacture safe cosmetics without damaging the skin barrier, providing an opportunity to use cosmetics that are expected to exfoliate to people, whose skin is sensitive to pH.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.251-256
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• 2017

Some rhizobacteria were isolated, that have copper resistance and can confer copper resistance to plants allowing growth under copper stress. Isolated strains Pseudomonas veronii MS1 and P. migulae MS2 produced 0.13 and 0.26 mmol/ml of siderophore, that is a metal-chelating agent, and also showed 64.6 and 77.9% of biosorption ability for Cu in 20 mg/L Cu solution, respectively. Copper can catalyze a formation of harmful free radicals, which may cause oxidative stress in organisms. Removal activity of 1,1-diphenyl-2-picryl hydrazyl radical and antioxidant capacity of strains MS1 and MS2 increased up to 82.6 and 78.1%, respectively compared to those of control at 24 h of incubation. They exhibited 7.10 and $6.42{\mu}mol$ ${\alpha}$-ketobutyrate mg/h of 1-aminocyclopropane-1-carboxylic acid deaminase activity, respectively, which reduced levels of stress hormone, ethylene in plants, and also produced indole-3-acetic acid and salicyclic acid that can help plant growth under abiotic stress. All these results indicated that these copper-resistant rhizobacteria could confer copper resistance and growth promotion to plants.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.73-77
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• 2002

The effect of salicylic acid (SA) on C $d^{2+}$ - induced physiological toxicity in Commelina communis was investigated. 3- weeks old Commelina communis was transferred to and grown in Hoagland solution in the presence or absence of 100 $\mu$M C $d^{2+}$ and SA for 3 weeks. In the treatment of C $d^{2+}$ + SA, the length of stem was increased to 0.7 cm for 3 weeks (C $d^{2+}$, 2.1cm; control, 7.2 cm). C $d^{2+}$ + SA reduced total chlorophyll content up to 86%, and changed chlorophyll a/b ratio below 1.6. C $d^{2+}$ + SA also reduced about 40-78% of water potential, but C $d^{2+}$ increased 16-39% from 1 week to 3 weeks. C $d^{2+}$ + SA also inhibited 27% of Fv/Fm, but in case of C $d^{2+}$, Fv/Fm was not changed. The treatment of C $d^{2+}$ + SA showed about 37-58% inhibition of photosynthetic activity when measured at various light intensity (500-1000 $\mu$mol $m^{-2}$ $s^{-1}$ ). In the case of C $d^{2+}$ treatment, photosynthetic activity was inhibited to 12-15%. Similar effect was found in terms of stomatal conductance. Therefore, it could be concluded that the treatment of C $d^{2+}$ + SA into plant decrease or block various physiological activities and lend to die by double effects of both chemicals.cts of both chemicals..