• Biomolecules & Therapeutics
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• v.23 no.6
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• pp.525-530
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• 2015

Ceramide is the most abundant lipid in the epidermis and plays a critical role in maintaining epidermal barrier function. Overall ceramide content in keratinocyte increases in parallel with differentiation, which is initiated by supplementation of calcium and/or vitamin C. However, the role of metabolic enzymes responsible for ceramide generation in response to vitamin C is still unclear. Here, we investigated whether vitamin C alters epidermal ceramide content by regulating the expression and/or activity of its metabolic enzymes. When human keratinocytes were grown in 1.2 mM calcium with vitamin C ($50{\mu}g/ml$) for 11 days, bulk ceramide content significantly increased in conjunction with terminal differentiation of keratinocytes as compared to vehicle controls (1.2 mM calcium alone). Synthesis of the ceramide fractions was enhanced by increased de novo ceramide synthesis pathway via serine palmitoyltransferase and ceramide synthase activations. Moreover, sphingosine-1-phosphate (S1P) hydrolysis pathway by action of S1P phosphatase was also stimulated by vitamin C supplementation, contributing, in part, to enhanced ceramide production. However, activity of sphingomyelinase, a hydrolase enzyme that converts sphingomyelin to ceramide, remained unaltered. Taken together, we demonstrate that vitamin C stimulates ceramide production in keratinocytes by modulating ceramide metabolicrelated enzymes, and as a result, could improve overall epidermal barrier function.

• Biomolecules & Therapeutics
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• v.27 no.6
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• pp.553-561
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• 2019

Rab25, a member of the Rab11 small GTPase family, is central to achieving cellular polarity in epithelial tissues. Rab25 is highly expressed in epithelial cells of various tissues including breast, vagina, cervix, the gastrointestinal tract, and skin. Rab25 plays key roles in tumorigenesis, mainly by regulating epithelial differentiation and proliferation. However, its role in skin physiology is relatively unknown. In this study, we demonstrated that Rab25 knock-out (KO) mice show a skin barrier dysfunction with high trans-epidermal water loss and low cutaneous hydration. To examine this observation, we investigated the histology and epidermal differentiation markers of the skin in Rab25 KO mice. Rab25 KO increased cell proliferation at the basal layer of epidermis, whereas the supra-basal layer remained unaffected. Ceramide, which is a critical lipid component for skin barrier function, was not altered by Rab25 KO in its distribution or amount, as determined by immunohistochemistry. Notably, levels of epidermal differentiation markers, including loricrin, involucrin, and keratins (5, 14, 1, and 10) increased prominently in Rab25 KO mice. In line with this, depletion of Rab25 with single hairpin RNA increased the expression of differentiation markers in a human keratinocyte cell line, HaCaT. Transcriptomic analysis of the skin revealed increased expression of genes associated with skin development, epidermal development, and keratinocyte differentiation in Rab25 KO mice. Collectively, these results suggested that Rab25 is involved in the regulation of epidermal differentiation and proliferation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.119-126
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• 2016

Skin is the largest organ that protects the body from the external environmental factors such as smog, cigarette smoke, UV. Protective skin barrier is composed with keratinizational keratinocytes and intercellular lipids such as ceramides, cholesterols and fatty acids combined by the lamellar liquid crystal structure. In this research, we confirmed that the Jeju wild ginseng (JWG) extracts dose-dependently increased the expression of serine-palmitoyltransferase (SPT) protein which is associated with ceramide biosynthesis. In addition, emulsion containing 5% JWG extract was applied on skin of human volunteers for 2 weeks and then significantly reduced transepidermal water loss (TEWL) compared to that of control group. As a results, JWG extract increased the biosynthesis of ceramides that is the key components of the skin lipid through enhancing expression of SPT. In addition, JWG extract reduced TEWL resulting in improvement of skin barrier function. In this context, we suggest that JWG extract could be used as a skin barrier enhancer and moisturing agents in cosmetic fileds.

• Journal of Embryo Transfer
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• v.13 no.3
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• pp.277-289
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• 1998

To establish a system for sperm swim-up separation through sucrose layer, indiscreet sperm migration should sufficiently to block but movement of sperm shouldn't inhibit. Thus, the effects of sucrose levels in sucrose layer, incubation times and types of sucrose layer on sperm separation were examined. And the results obtained were as follows; 1. Layer of 10mM sucrose inhibited sperm swim-up migration through sucrose layer. 2. Incubation for 25 minutes without sucrose layer significantly increased sperm swim-up migration. However, incubation for 10 minutes to induce swim-up through sucrose layer significantly stimulated sperm migration and maintained sperm movement. 3. There was no significant difference between Type I and Type II in barrier effect of sucrose layer. However, sucrose layer of Type II with shorter distance of barrier was efficient for sampling. To elucidate a function of follicular fluid on sperm chemotaxis using in vitro system of sucrose layer of Type II and incubation for 10 minutes, the effects of dilution, heat treatment, and protein and lipid extracts of follicular fluid on sperm swim-up separation were examined. And the results obtained were as follows; 4. Follicular fluid stimulated sperm migration and movement, and significantly-attracted capacitated-sperm at 10% level. 5. Follicular fluid heated at 55$^{\circ}C$ for 30 minutes maintained the effect of follicular fluid stimulating sperm migration and movement. 6. Follicular protein stimulated sperm movement that was reduced by filtration of the protein. 7. Follicular lipid didn't significantly stimulate sperm migration and movement. 8. Both of follicular protein and lipid reduced the effect of follicular fluid stimulating sperm migration and movement. In conclusion, sucrose layer could be used for a barrier against indiscreet sperm migration by swim-up. And follicular fluid stimulated migration and movement of sperm and attracted capacitated-sperm through sucrose layer. Especially, heat-resistant protein of follicular fluid stimulated sperm migration.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.543-553
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• 1992

Properties of unitary ATP-sensitive $K^+$ channels were studied using planar lipid bilayer technique. Vesicles were prepared from bullfrog (Rana catesbeiana) skeletal muscle. ATP-sensitive $K^+$ (K (ATP)) channels were identified by their unitary conductance and sensitivity to ATP. In the symmetrical solution containing 200mM KCI, 10mM Hepes, 1mM EGTA and pH 7.2, single K (ATP) channels showed a linear current-voltage relations with slight inward rectification. Slope conductance at reversal potential was $60.1{\pm}0.43$ pS(n=3)). Micromolar ATP reversibly inhibited the channel activity when applied to the cytoplasmic side. In the range of -50~＋50 mV, the channel activity was not voltage-dependent, but the channel gating within a burst was more frequent at negative voltage range. Varying the concentrations of external/internal KCl(mM) to 40/200, 200/200, 200/100 and 200/40 shifted reversal potentials to $-30.8{\pm}2.9$(n=3), $-1.1{\pm}2.7$(n=3), 10.5 and 30.6(mV), respecrivety. These reversal potentials were close to the expected values by the Nernst equation, indicating nearly ideal selectivity for $K^+$ over $Cl^-$. Under bi-ionic conditions of 200mM external test ions and 200mM internal $K^+$, the reversal potentials for each test ion/K pair were measured. The measured reversal potentials were used for the calculation of the releative permeability of alkali cations to $K^+$ ions using the Goldman-Hodgkin-Katz equation. The permeability sequence of 5 cations relative to $K^+$ was $K^+$(1), $Rb^+$(0.49), $Cs^+$(0.27), $Na^+$(0.027) and $Li^+$(0.021). This sequence was recognized as Eisenman's selectivity sequence IV. In addition, modelling the permeation of $K^+$ ion through ATP-sensitive $K^+$ channel revealed that a 3-barrier 2-site multiple occupancy model can reasonably predict the observed current-voltage relations.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.275-284
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• 2024

Worldwide, cardiovascular disease is the main cause of death, which accordingly increased by hyperlipidemia. Hyperlipidemia therapy can include lifestyle changes and medications to control cholesterol levels. Statins are the medications of the first choice for dealing with lipid abnormalities. Rosuvastatin founds to control high lipid levels by hindering liver production of cholesterol and to achieve the targeted levels of low-density lipoprotein cholesterol, another lipid lowering agents named ezetimibe may be used as an added therapy. Both rosuvastatin and ezetimibe have low bioavailability which will stand as barrier to decrease cholesterol levels, because of such depictions, formulations of this combined therapy in nanotechnology will be of a great assistance. Our study demonstrated preparations of nanoparticles of this combined therapy, showing their physical characterizations, and examined their behavior in laboratory conditions and vivo habitation. The mean particle size was uniform, polydispersity index and zeta potential of formulations were found to be in the ranges of (0.181-0.72) and (-13.4 to -6.24), respectively. Acceptable limits of entrapment efficiency were affirmed with appearance of spherical and uniform nanoparticles. In vitro testing showed a sustained release of drug exceeded 90% over 24 h. In vivo study revealed an enhanced dissolution and bioavailability from loaded nanoparticles, which was evidenced by calculated pharmacokinetic parameters using triton for hyperlipidemia induction. Stability studies were performed and assured that the formulations are kept the same up to one month. Therefore, nano formulations is a suitable transporter for combined therapy of rosuvastatin and ezetimibe with improvement in their dissolution and bioavailability.

• Journal of Veterinary Clinics
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• v.25 no.5
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• pp.330-339
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• 2008

Ceramide, cholesterol and free fatty acids are the major intercellular lipids, maintaining the integrity of the skin barrier. However, the roles of these lipids in canine skin barrier function are little known. The aim of this study was to evaluate the repairing effects of 2% ceramide (CER), 2% cholesterol (CHO), 2% linoleic acid (LIN) and 2% intercellular lipid mixture (ILM) on damaged canine skin barrier by 1.25% sodium lauryl sulphate (SLS). Transepidermal water loss (TEWL), skin hydration, skin pH and skin thickness were assessed. Histological profiles and transmission electron microscopic (TEM) profiles were assessed on day 12. SLS effectively induced the canine skin barrier damage. TEWL was significantly decreased by topical application of CER and ILM in SLS and vehicle-treated skin on day 8 and 12, respectively (p < 0.05, p < 0.0 I). By end of the experiment all lipids significantly decreased the TEWL as compared with SLS and vehicle control, but CER and ILM more significantly decreased the TEWL than UN and CHO, respectively (p < 0.01). Skin hydration was significantly increased by CER and ILM during experimental periods (p < 0.01). Skin pH was significantly decreased by CER, LIN and ILM. In histological profiles, the thickness of the stratum corneum (SC) was significantly increased by the SC lipids as compared with vehicle and SLS (p < 0.01). Especially, CER and ILM showed more prominent improvement of barrier recovery. In TEM of the SC, SLS induced exfoliations of corneodesmosomes in the SC, and CER and ILM effectively protected exfoliations of corneodesmosomes on SLS-damaged canine skin. These results indicated that topical application of CER and ILM dramatically improved damaged-skin barrier function by SLS. Also, it was considered that the use of CER or ILM was recommended for the management of skin barrier dysfunction by irritant and inflammatory skin disorders such as atopic dermatitis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.29 no.2 s.43
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• pp.205-232
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• 2003

Ursolic acid (UA) and Oleanolic acid (ONA), known as urson, micromerol and malol, are pentacyclic triterpenoid compounds which naturally occur in a large number of vegetarian foods, medicinal herbs, and plants. They may occur in their free acid form or as aglycones for triterpenoid saponins, which are comprised of a triterpenoid aglycone, linked to one or more sugar moieties. Therefore UA and ONA are similar in pharmacological activity. Lately scientific research, which led to the identification of UA and ONA, revealed that several pharmacological effects, such as antitumor, hepato-protective, anti-inflammatory, anticarcinogenic, antimicrobial, and anti-hyperlipidemic could be attributed to UA and ONA. Here, we introduced the effect of UA and ONA on acutely barrier disrupted and normal hairless mouse skin. To evaluate the effects of UA and ONA on epidermal permeability barrier recovery, both flanks of 8-12 week-old hairless mice were topically treated with either 0.01-0.1 mg/ml UA or 0.1-1 mg/ml ONA after tape stripping, and TEWL (Transepidermal water loss) was measured . The recovery rate increased in those UA or ONA treated groups (0.1 mg/ml UA and 0.5 mg/ml ONA) at 6 h more than $20\%$ compared to vehicle treated group (p<0.05). Here, we introduced the effects of UA and ONA on acute barrier disruption and normal epidermal permeability barrier function. For verifying the effects of UA and ONA on normal epidermal barrier, hydration and TEWL were measured for 1 and 3 weeks after UA and ONA applications (2mg/ml per day). We also investigated the features of epidermis and dermis using electron microscopy (EM) and light microscopy (LM). Both samples increased hydration compared to vehicle group from f week without TEWL alteration (p<0.005). EM examination using RuO4 and OsO4 fixation revealed that secretion and numbers of lamellar bodies and complete formation of lipid bilayers were most prominent $(ONA{\geq}UA>Vehicle)$. LM finding showed that thickness of stratum corneum (SC) was slightly increased and especially epidermal thickening and flattening was observed (UA>ONA>Veh). We also observed that UA and ONA stimulate epidermal keratinocyte differentiation via $PPAR\;\alpha$. Protein expression of involucrin, loricrin, and filaggrin increased at least 2 and 3 fold in HaCaT cells treated with either $ONA\;(10{\mu}M)$ or UA $(10{\mu}M)$ for 24h respectively. This result suggested that the UA and ONA can improve epidermal permeability barrier function and induce the epidermal keratinocyte differentiation via $PPAR\;{\alpha}$. Using Masson-trichrome and elastic fiber staining, we observed collagen thickening and elastic fiber elongation by UA and ONA treatments. In vitro results of collagen and elastin synthesis and elastase inhibitory activity measurements were also confirmed in vivo findings. These data suggested that the effects of UA and ONA related to not only epidermal permeability barrier functions but also dermal collagen and elastic fiber synthesis. Taken together, UA and ONA can be relevant candidates to improve epidermal and dermal functions and pertinent agents for cosmeseutical applications.

• YAKHAK HOEJI
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• v.27 no.1
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• pp.11-19
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• 1983

Rifampicin-arginine complex was prepared to increase the solubility and dissolution rate of rifampicin. Solvation method was applied to make the complex and its formation was identified by the solubility method, powder x-ray diffractometry, differential thermal analysis and spectroscopic determination. The complex was formed in the molar ratio of 1 : 1 which was proved by the slope ratio method and continuous variation method. The complex was a non-crystalline form determined by the x-ray powder diffractometric analysis. The solubility of complex in water was significantly higher than that of rifampicin itself. The stability constant and thermodynamical properties of the complex were determined to investigate the solubilization phenomena. The thermodynamic data showed that the complexation between rifampicin and arginine was an exothermic and spontaneous reaction. Simulated absorption studies carried out through the artificial lipid barrier in artificial gastric and intestinal juices. The results showed that the complex had an enhanced absorption rate of rifampicin nearly twice compared with that of rifampicin itself.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.1
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• pp.65-73
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• 2021

It is very important to control the inflammation of the skin because it can develop into diseases such as atopy as well as scarring and aging. In this work, we recently identified the in vitro synthesis of specialized pro-resolving mediators (SPMs) known to control inflammation in the human body and the applicability of cosmetics. Using recombinant protein of lipoxygenase from Glycine max, we succeeded to prepare mixtures of mono- or di-hydroxy DHA named as S-SPMs and used them for in vitro efficacy test. To investigate anti-inflammatory effect of S-SPMs, mRNA level of TNF-α and IL-6 were analyzed. Under UVB exposed condition, expression of both were decreased by S-SPMs treatment. And we observed reduced production of nitric oxide (NO) by S-SPMs application under the condition with diesel particulate matter (DPM). At the same experimental condition, malondialdehyde (MDA) production was decreased by S-SPMs, indicating the inhibitory effect of S-SPMs in lipid peroxidation. In addition, S-SPMs treatment resulted in reduction of matrix metalloproteinases-1 (MMP-1) expression and elevation of procollagen type I synthesis. Together with this, mRNA level of filaggrin and loricrin were increased by S-SPMs, indicating enhancement of skin barrier function. These results demonstrate that S-SPMs is a good candidate to develop as a cosmetic ingredient for anti-inflammation, anti-wrinkle, and improvement of skin barrier function.