• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.111-115
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• 1998

We investigated the stability of all-trans-retinol on the liquid crystalline O/W emulsion composed of mainly alkyl polyglycerine, alkyl polyglucose and glycerine, and compared the activity of all-trans-retinol in the various forms of liquid crystal. Under certain conditions, novel liquid crystalline gel was formed around oil droplets, and layers of this liquid crystalline gel were very wide and rigid. (SWLC; Super Wide Liquid Crystal) SWLC was very helpful to stabilize retinol in O/W emulsion. After storage at 45 C for 4 weeks, all-trans-retinol in O/W emulsion composed of SWLC retained above 85% of the activity upon HPLC analysis, whereas those within no liquid crystalline emulsion gave 47% and normal liquid crystalline emulsion composed of fatty alcohols gave 40 60%. Retinol in oil phase is nealy insoluble in pure water, but in cosmetic emulsion systems can be slightly solubilized into water because emulsifiers and polyols in emulsion systems function as solubilizers. In this case, water in outer phase acts as a media for oxygen transporation$.$and thus destabilizes retinol. As a result, retinol in O/W emulsion has a tendency to become unstable. SWLC surrounding oil droplet which contains retinol is wide and rigid, therefore reduces contact between inner phase and outer phase To make SWLC, properties of emulsifiers are very important phase transition temperature should be high, and the structure of surfactants should be bulky, and their ratio should be suitable to make rigid and wide liquid crystalline gel layer in order to reduce contact between retinol in inner phase and water in outer phase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.24-38
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• 1997

Using the all-trans-retinol which is double-capsulated with matrix, we investigated its stability and the change of the epidermal thickness. The proprietary MDC comprise two steps of capsulation of retinol, i.e., primary microcapsulation with collagen and then secondary capsulation with gellan gum. We compared the activity of all-trans-retinol in various forms such as (1) simply in O/W, (2) in W/O emulsion, (3) in primary capsulted form in O/W emulsion, or (4) in MDC in O/W emulsion. After storage at 45$^{\circ}C$ for 4 weeks, retinol in MDC in O/W emulsion retained 92% of the activity compared to the standard material upon HPLC analysis, whereas the primary capsule gave 70%, the O/W emulsion form 47% and the W/O emulsion 78%. The retinol in MDC in O/W induced the siginificant increase in epidermal thickness compared to the vehicle.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.71-76
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• 2010

Skin irritation caused by retinol and retinoic acid results in mild erythema called as retinoid dermatitis. To develop compounds modulating the retinoid dermatitis, we tried to establish the screening method for retinoid dermatitis. At first we examined the inflammatory cytokine profile in neonatal human dermal fibroblasts which are known to be one of main site of retinoid action. As a result, interleukin-8 (IL-8) and monocytes chemoattractant protein-1 (MCP-1) were significantly produced by all trans retinoic acid (ATRA) and all trans retinol (ATROL) in dermal fibroblasts. Especially the production of MCP-1 was more than that of IL-8. The production of MCP-1 by retinoid was dose-dependently increased, continuing up to 24 hrs. After then using ethacrynic acid (ECA) known to reduce mouse ear edema induced by ATRA, we checked whether ECA suppressed the production of MCP-1. As a result, ECA effectively suppressed the production of MCP-1 in the ATRA- or ATROL-treated-fibroblasts. These results suggested that screening method effectively reflects the in vivo anti-inflammatory activity of ECA. It was reported that citral inhibited the enzyme involved in the conversion of ATROL to ATRA. We showed that citral suppressed the production of MCP-1 in ATROL-treated fibroblasts. We expect these finding might be helpful to find useful compounds modulating the side effects of retinoid or retinoid dermatitis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.116-122
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• 1998

It is well known that all-trans-retinol is not only very unstable in heat, light, air, and water, but also skin-irritant despite a good anti-wrinkle effect. Therefore, it is very difficult to stabilize retinol and make the safe retinol containing cosmetics by using a certain concentration of retinol with real effect. In order to dissolve these problems and apply retinol for skin care cream, firstly retinol is to be encapsulated in the vesicle called Liposphere (pseudo-liposome) which is made by homogenizing under high pressure the mixtures of lecithin, retinol, caprylic/capric triglyceride, and hydroalcoholic solution ; and then this retinol containing Liposphere is to be intercalated in lamellar liquid crystal layer which is prepared by emulsifying in an optimal ratio the mixtures composed of non-ionic emulsifier (cetearyl glucoside, sorbitan stearate & sucrose cocoate etc), cetearyl alcohol, stearic acid, cholesterol, and ceramide. In addition, the stability of the retinol containing oil in water cream by adding the polymeric emulsifier such as acrylate /C10-30 alkyl alkylate crosspolymer is to be ensured even at 55 C. Retinol containing oil in water cream prepared through above procedure could be very stable at 45 C for at least 50 days. The structure identification of lamellar liquid crystal was determined using polarized light microscope and electron microscope Conclusively, we could make the very stable retinol containing oil in water cream by triple procedure, that is, encapsulation of retinol in Liposphere, intercalation of retinol in lamellar liquid crystal layer, and assurance of the high temperature stability of cream even at 55 C.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.134-144
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• 2019

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased with the incidence of obesity; however, the underlying mechanisms are unknown. In this study, high-resolution metabolomics (HRM) along with transcriptomics were applied on animal models to draw a mechanistic insight of NAFLD. Wild type (WT) and catalase knockout (CKO) mice were fed with normal fat diet (NFD) or high fat diet (HFD) to identify the changes in metabolic and transcriptomic profiles caused by catalase gene deletion in correspondence with HFD. Integrated omics analysis revealed that cholic acid and $3{\beta}$, $7{\alpha}$-dihydroxy-5-cholestenoate along with cyp7b1 gene involved in primary bile acid biosynthesis were strongly affected by HFD. The analysis also showed that CKO significantly changed all-trans-5,6-epoxy-retinoic acid or all-trans-4-hydroxy-retinoic acid and all-trans-4-oxo-retinoic acid along with cyp3a41b gene in retinol metabolism, and ${\alpha}/{\gamma}$-linolenic acid, eicosapentaenoic acid and thromboxane A2 along with ptgs1 and tbxas1 genes in linolenic acid metabolism. Our results suggest that dysregulated primary bile acid biosynthesis may contribute to liver steatohepatitis, while up-regulated retinol metabolism and linolenic acid metabolism may have contributed to oxidative stress and inflammatory phenomena in our NAFLD model created using CKO mice fed with HFD.

• Toxicological Research
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• v.17 no.2
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• pp.143-149
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• 2001

In the present study, we examined eye irritation oj six anti-wrinkle agents (ascorbic acid, glycolic acid, all trans-retinoic acid, ginseng extract, retinol, EB). We also compared eye irritation with skin irritation and cytotoxicity in HaCaT cells by these agents. The highest eye irritation was found in glycolic acid, but all trans-retinoic acid showed the highest skin irritation. The rank of eye irritation was not correlated with the cytotoxicity of agents. This result shows that eye irritation potency by these agents were not correlated with skin irritation potency, and cytotoxicity in HaCaT cells.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.9-23
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• 1997

Retinoids are essential regulators of spithelial cell growth and celluar differentiation. They are also known to be effective in photoaging. It was reported that topical application of retinoic acid improves facial wrinkle carsed by collagen synthesis reduction in photodamaged skin. Collagen synthesis by retinoic acid may contribute to the wrinkle effacement. Since celluar retinoic acid binding protein II is slsctively induced in human skin and dermal fibroblasts in vitro by retinoic acid, this response can be used to mesure retinoids potency and activity. In order to know the activity of retinoids and their relations with collagen synthesis, we treated dermal fibroblasts with retinoids for 48 hours at 10-6-10-7M and measured CRABPII mRNA level by quantitative Nortern blotting. We also measured the rate of collagen systhesis by retinoids using 3-dimensional dermal equivalent. CRABPII mRNA level was increased 3-fold by retinoic acid, 2.1-fold by retinol and 1.4-fold by retinaldehyde. Collagen systhesis was increased 34% by all-trans retinioc acid, 26% by retinol, 17% by retinaldehyde and 7% by retinyl palmitate. From the above results, retinoids were found to be a potent indecers of CRABPII mRNA and collagen synthesis. Though retinoic acid was the most effective, its use has been restricted because of the side effects. Instead, retinol can be a best candidate in cosmetics for the treatment of photodamaged skin in terms of efficacy and safety.

• YAKHAK HOEJI
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• v.45 no.3
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• pp.310-319
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• 2001

To compare skin irritation and cytotoxicity of anti-wrinkle agents, we examined skin irritation of six anti-wrinkle agents (ascorbic acid, glycolic acid, all trans-retinoic acid, ginseng extract, retinol, EB) in New Zealand white rabbit. Cytotoxicity of these agents was determined by MTT [tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] at multi-time points in cultured HaCaT cell, a human immortalized keratinocyte cell. We then analyzed correlation between skin irritation and cytotoxicity by spearman's rank correlation analysis. All trans-retinoic acid showed the highest primary irritation index (0.92) in skin irritation test. Being all the six agents not irritant, retinal showed the most cytotoxic agents. The correlation between skin irritation and cytotoxicity ($IC_{50}$/ at different time point was 0.814, 0.757, 0.814 and 0.7 at 3, 24, 48 and 72 h, respectively. We also fecund that IC$_{20}$ and IC$_{80}$ of these agents showed similar correlation with skin irritation. These results therefore demonstrated that there is close correlation between skin irritation and cytotoxicity $IC_{50}$/ value by MTT in HaCaT cell at early time points by anti-wrinkle agents or IC$_{20}$ value. $IC_{50}$/ at earily time point or IC$_{20}$ values may be reliable alternative determinant of skin irritation.n.

• Journal of Food Hygiene and Safety
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• v.21 no.3
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• pp.171-180
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• 2006

Peroxisome proliferatorr-activated receptor-gamma $(PPAR{\gamma})$ must form a heterodimer with the retinoid-X receptor (RXR) to bind DNA, and its transcriptional activity is thought to be maximized by ligands specific for either receptor. Activated $(PPAR{\gamma})$ and $(PPAR{\gamma})$ ligands may influence tumor growth through regulation of the tumor suppressor PTEN. Our aim in this study was to determine whether co-stimulation with the $(PPAR{\gamma})$ ligand, ciglitazone, and RXR ligand can synergistically upregulate PTEN in human acute promyelocytic leukemia (APL) cells and consequently potentate the inhibition of cell growth and cell cycle progression of these cells. Human leukemia cell line, HL-60 cells were exposed to all-trans-retinol and ciglutazone. The PTEN expression was measured as the level of PTEN mRNA expression by RT-PCR and as the level of PTEN expression by western blot analysis. Cell cycle analysis was carried out by a propidium iodide (PI) staining method and analyzed with a FACScan. The $(PPAR{\gamma})$ ligand, ciglitazone, and the RXR ligand, retinoic acid, upregulated PTEN expression by HL-60 cells in time- and dose-dependent manners, respectively. This was significantly enhanced by a combination of both ciglitazone and retinoic acid. Moreover, these compounds synergistically induced arrests of both cell growth and the $G_l$ phase of the cell cycle. Thus, the activation of the $(PPAR{\gamma})$:RXR heterodimer may represent a regulatory pathway for human leukemia cells and there may be important roles for $(PPAR{\gamma})$ and RXR ligands in prophylactic and therapeutic approaches fur controlling leukemia through the upregulation of PTEN.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.110-110
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• 2001

To compare skin irritation and cytotoxicity of anti-wrinkle agents, we examined skin irritation of six anti-wrinkle agents (ascorbic acid, glycolic acid, all trans-retinoic acid, ginseng extract, retinol, EB) in New Zeland white rabbit.(omitted)