• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1396-1400
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• 2007

In this study, poly(iso-butyl methacrylate-co-ethylene glycol dimethacrylate) [poly(iso-BMA-co-EGDMA)] microgel was prepared and used as a face powder additive. The spreading, adhesiveness, and skin reactivity of poly(iso-BMA-co-EGDMA) microgel-containing face powder II were investigated and compared with the same properties of commercially available Silica bead 700-containing face powder I. In the results, the particle size of the poly(iso-BMA-co-EGDMA) microgel was significantly swelled as a result of sebum absorption. Face powder II showed a lower primary irritation index and a higher adhesiveness than did face powder I. Face powder I showed a low sebum absorption ratio and a relatively high rate of sebum absorption, whereas face powder II, contrastingly, exhibited a high sebum absorption ratio and a low rate of sebum absorption, which properties would reduce the phenomena of facial strain and sliminess. These results indicate that poly(iso- BMA-co-EGDMA) microgel has outstanding sebum absorption characteristic and adhesiveness, and thus that it is a good candidate for use as a face powder additive.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1431-1443
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• 2009

In order to investigate the therapeutic effect of SSC, NC/Nga animal model resembling the AD-like symptoms were used to measure the changes in cytokines and histology. SSC prescription group showed significant decrease in the atopic dermatitis clinical index by 40.2% compared to that of the control. The SSC prescription had significant effect on immune cells that are related to inducing AD symptoms. SSC prescription also increased the ratio of immune cells in DLN that were not directly involved in AD symptoms. SSC prescription group showed significant decrease in the level of cytokines within spleen cells and DLN. The prescription also decreased the level of immunoglobulin IgE levels in serum by 25.3%. The thickness of epidermis and dermis as well as the precipitation of erythrocytes were also observed. The results indicate the therapeutic effect of SSC in the treatment of atopic dermatitis through immune modulation. The study will provide a broader applications in the treatment of atopic dermatitis. Particularly, skin regeneration effect and supplemental use of topical application of SS in atopic dermatitis treatment had been reported previously, and further investigation on the dose dependent effect as well as skin irritation studies of SS should be followed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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• pp.164-173
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• 2012

Objectives: Epichlorohydrin is a material that has been predicted to have high volatility and strong toxicity and is used normally in working area. Therefore, the hazardous and dangerous level and the foreign management system about epichlorohydrin should be invested at home and abroad and through hazard assessment for occupational environment measurement and exposure status of industrial workers in domestic working area. Methods: To assess risk and to suggest Development and Adoption to prevent health damage of workers owing to the epichlorohydrin exposure, the hazardousness and dangerousness of epichlorohydrin and its practical examples and regulation level for domestic and abroad health impairment are researched on the base of various references. Results: The epichlorohydrin caused skin and mucus membrane irritation, respiratory paralysis, kidney and live damage under the influence of acute toxicity and in animal study, it was confirmed as a doubtful carcinogenic substance to trigger reducement of sperm number and reproduction ability, abnormal spermatogenesis, mutagen, increase of forestomach epithelium and occurrence of papilloma and so on, as well as it induced stimulus asthma and allergic contact dermatitis for exposure workers. Conclusions: Epichlorohydrin was found to occur allergic contact dermatitis, carcinogenesis doubt and reproduction toxicity and was verified as a material which would be established reinforcement of management level to care health of handlers, such as denotement dangerousness of skin absorption.

• Korean Journal of Materials Research
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• v.34 no.2
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• pp.95-104
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• 2024

Nanoparticles are commonly used to avoid the opaque white color of TiO₂ based sunscreen. However, a dispersing agent is typically required because of the tendency of the nanoparticles (NPs) to agglomerate. Stearic acid is one kind of dispersing agent often used for sunscreen products. However, according to the MSDS data sheet on stearic acid, stearic acid is highly hazardous to aquatic life and causes irritation on human skin. To avoid this problem, in this study a safer organic dispersing agent extracted from Korean seaweed has been studied to disperse TiO₂ nanoparticles, and further use as an active agent in sunscreen products. The presence of phytochemicals in seaweed extract, especially alginate, can disperse TiO₂ nanoparticles and improve TiO₂ dispersion properties. Results show that seaweed extract can improve the dispersion properties of TiO₂ nanoparticles and sunscreen products. Reducing the agglomeration of TiO₂ nanoparticles improves sunscreen properties, by making it less opaque white in color, and increasing UV protection value. It was also confirmed that adding seaweed extract into sunscreen products had no irritating effects on the human skin, making it more desirable for cosmetics application.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.3
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• pp.251-259
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• 2024

The skin barrier plays an important role in maintaining healthy skin by preventing external irritation and water loss in the body. In the skin, hyaluronic acid (HA) is synthesized by the enzyme hyaluronic acid synthase (HAS), which functions as a natural moisturizing factor and is involved in maintaining water retention and barrier function. Therefore, in this study, the effect of the Prunus yedoensis bark ethyl acetate fraction (PYBEAF) on HA synthesis in HaCaT cells was confirmed. Cytotoxicity evaluation was performed through MTT assay, and the amount of HA synthesis in HaCaT cells was confirmed through ELISA through PYBEAF treatment. The levels of HAS-2, HAS-3 mRNA expression were analyzed using qRT-PCR, and the protein expression level and signaling pathway were confirmed through western blotting. Consequently, PYBEAF was involved in the MAPK and CREB signaling pathways, increasing the amount of HA production through HAS-2 synthesis. This suggests that PYBEAF is effective in improving barrier function by increasing HA synthesis, which plays an important role in moisturizing and maintaining skin moisture.

• Journal of Conservation Science
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• v.33 no.4
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• pp.255-266
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• 2017

Chemically derived pesticides have been used to prevent biological damage to domestic cultural property. However, their use is gradually being restricted due to the harmful effects on the human body and environment. Therefore, there is a growing interest in the search for new antifungal biopharmaceuticals whose safety has been confirmed by toxicity evaluation through animal experiments. This paper presents methods of toxicity evaluation of natural biocides using Sprague-Dawley rats and New Zealand White (NZW) rabbits. Safety of the natural biocide extract of Asarum sieboldii was evaluated using single-dose oral and dermal toxicity tests in Sprague-Dawley rats, and eye and skin irritation tests in NZW rabbits. The extract has proven antimicrobial and insecticidal activities against wood-rotting fungi and termites. After single oral administration to rats, the $LD_{50}$ values were determined to be over 4,000 and 2,000 mg/kg for males and females, respectively. After single dermal administration to rats, the $LD_{50}$ values exceeded 10,000 mg/kg for both males and females. The extract was identified to be non-irritant to the rabbit eye, and only slightly irritant to the rabbit skin. In this study, we confirmed the safety of the A sieboldii extract through animal testing. Due to the harmfulness of humidifier disinfectants, focus is on the safety of chemical pesticides, and toxicity evaluation is suggested as the basic method for hazard evaluation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.3
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• pp.239-250
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• 2024

In this study, we investigated the skin safety, antioxidant, moisturizing, and anti-inflammatory effects of a composite extract of Prunus mume flower, Lonicera japonica flower, Chrysanthemum indicum flower, and Phyllostachys bambusoides (Royal TheraTea Guard^TM, RTG), which has been used as an internal medicine in the royal medical treatment for preventing skin damage caused by external environmental factors. In a cytotoxicity test on HaCaT cells, RTG complex extract showed no change in cell viability at concentrations of 0.125, 0.25, 0.5, and 1%, and a skin irritation index of 0.00 in a human patch test, confirming that it is non-irritating to the skin. The antioxidant effects was confirmed by the presence of 497.83 ㎍ GAE/g of polyphenols and increased DPPH radical scavenging activity, with a significant increase in catalase activity in the stratum corneum, showing potential as an antioxidant that protects cells from oxidative stress. The anti-inflammatory effects was observed through reduced erythema in skin stimulated by tape stripping and treated with fine dust in keratinocytes. The moisturizing effects was shown by increased expression of hyaluronan synthase (HAS)2, 3 and keratin1 in keratinocytes treated with fine dust compared to the control group, as well as increased skin moisture content and decreased skin roughness. These results suggest RTG can be used as a cosmetic ingredient to prevent skin damage caused by external environmental factors.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.1
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• pp.84-94
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• 1995

Fragrance oil was encapsulated with B-Capsulation and Arabic gum for double Encapsulation to improve the demerits-cause the skin irritation, allergy and lack of odor fixative-. Powder fragrance was obtained from the paste phase using the method of spray dry. From the analyses (GC, IR, UV) and sensory teste, it was identified that frogrance was encapsulated in our reservoir.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.150-165
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• 2002

The purpose of this study was to evaluate bacteriocin activity against human flora. Lactobiocin, a bacteriocin produced by Lactococcus sp. HY 449, inhibited the growth of Starphylococcus epidermidis, Starphylococcus aureus, Streptoccoccus pyogenes and Propionibacterium acnes. When crude bacteriocin was added to indicator cells during logarithmic growth, the optical density(O.D 650nm) of cells without bacteriocin increase after 5h of incubation. Whereas in the presence of bacteriocin, the O.D of cell suspensions decreased. The similar patterns were observed for absorbance readings at 280 nm and 260 nm. The release of cellular components when cell were treated with Lactobiocin suggests some degree of membrane damage or cell lysis. Scanning electron microscopy of cells following treatments with Lactobiocin in PBS buffer revealed disruptures of cell morphology. These results indicate that bacteriocin appears to cause cell lysis of tested strains. In cytotoxicity on human fibroblast, LD$\_$50/ of Lactobiocin was ca. 50 mg/ml and no change was observed cell proliferation at the same concentration. Any irritation and allergic reaction did not observed when evaluated by human patch test for Lactobiocin.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.294-302
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• 2003

Unstable cosmetic active ingredients could be degraded rapidly by chemical and photochemical process. Particularly, some of active ingredients like retinol are known to cause skin irritation when applied on the skin excessively. Therefore, it has become a very important issue to encapsulate cosmetic actives for the stabilization and skin protection. This study was performed in order to prepare a chitosan microcapsule containing liposoluble cosmetic actives and to investigate the stabilization effect of actives when chitosan microcapsule was applied in cosmetic formulation. Chitosan, deacetylated form of chitin, has been of interest in the industrial applications due to its biocompatibility, biodegradability, non-toxicity, antimicrobial activity and also used as a wall material of capsule. Retinol was used as a core material and was stabilized by a wall of chitosan and antioxidants. The chitosan microcapsule containing retinol(CMR) was prepared by using coacervation method and W$_1$/O/W$_2$ emulsification techniques. The CMR has 0.5~10.0 ${\mu}{\textrm}{m}$ size distribution and a long-term stability of more than an year inside the cosmetic formulation(O/W). Remaining retinol percentages at 45$^{\circ}C$ after 8 weeks in the CMR dispersion were 15.6%(pH 4.0), 59.8%(pH 6.0) and 65.0%(pH 6.0 with antioxidant) respectively. Retinol stability when added CMR inside a ONV emulsion was better than that of ONV emulsion added non-capsulated retinol. As a result, remaining retinol at 45$^{\circ}C$ after 8 weeks in O/W emulsion added non-capsulated retinol and O/W emulsion containing CMR was 12.7%, 70.5% respectively. It appeared that chitosan treated microcapsule may be used for a potential encapsulation method of unstable active ingredients.