• Biomolecules & Therapeutics
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• 제23권6호
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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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• 제27권6호
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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.

• 대한화장품학회지
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• 제42권2호
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• pp.119-126
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• 2016

피부는 스모그, 담배연기 및 UV와 같은 외부환경으로부터 신체를 보호하는 가장 큰 기관이며, 보호 기작으로서 각질세포와 그 사이를 메우고 있는 세라마이드, 콜레스테롤, 지방산 등의 세포간지질이 라멜라 액정 구조로 피부 장벽을 이루고 있다. 본 연구에서는 세포간지질 중 세라마이드 생합성과 관련되어 있는 세린-팔미토일 전이효소(serine-palmitoyltransferase, SPT) 발현을 western blot으로 확인한 결과, 제주산양산삼 추출물이 농도의존적으로 SPT 단백질 발현을 증가시킴을 확인하였다. 또한 제주산양산삼 추출물을 5% 함유한 제형을 2주간 피부에 도포 후 TEWL을 측정하였을 때, 제주산양산삼 추출물을 함유한 에멀젼 도포부위의 TEWL이 대조군에 비해 유의적으로 감소하는 것을 확인하였다. 이 연구결과는 제주산양산삼 추출물이 SPT의 발현 증가를 통해 세포간 지질의 핵심성분인 세라마이드의 생합성을 증가시켰음을 보여준다. 따라서 제주산양산삼 추출물은 피부장벽기능을 개선시켜 TEWL 감소 효과를 나타내며, 이를 통해 화장품 분야에서 피부장벽 강화 및 보습소재로서 사용될 수 있다고 사료된다.

• 한국수정란이식학회지
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• 제13권3호
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• pp.277-289
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• 1998

정자의 무분별한 이동을 충분히 억제하면서 운동성을 저해하지 않는 sucrose 층으로부터의 swim-up 분리체계를 구축하기 위하여, 정자의 이동에 장애가 될 수 있는 sucrose 층에 첨가되는 sucrose수준과 정자의 이동과 운동을 극대화시킬 수 있는 배양시간 및 sucrose 이중층의 형태를 조사하였던 바, 얻어진 결과는 다음과 같다. 1. 10mM의 sucrose 층은 정자의 swim-up 이동을 억제하였다. 2. Sucrose 층을 이용하지 않은 swim-up 분리에서 25분간 배양후 회수된 정자의 수가 유의하게 증가되었다. 한편, sucrose 층을 이용한 swim-up 분리에서 10분간 배양후 회수된 정자의 수가 유의하게 증가되었으며 정자의 운동성도 유지되었다 3. Sucrose 이중층 Type I과 Type II 간에 장애효과에는 유의한 차이는 없었으나, 장애공간이 짝은 Type II 이중층에서 시료 채취가 편리하였다. 정자의 주화적 이동과 관련하여 난포액의 기능 을 밝히기 위하여, 난포액의 희석과 열처리 및 난포액으로부터 추출한 단백질과 지질이 Type II Sucrose 층으로부터 10분간 배양한 정자의 swim-up 분리에 미치는 효과를 조사하였던 바 얻어진 결과는 다음과 같다 4. 난포액은 정자의 이동과 운동을 자극하였고 수정능획득정자를 유인하였으며, 특히 10% 난포액에서 수정능획득정자의 유인효과가 가장 크게 나타났다. 5. 저온 열처리 (56$^{\circ}C$, 30분)는 정자의 이동과 운동을 자극하는 난포액의 효과를 감소시키지 않았다. 6. 난포액으로부터 추출한 단백질 성분은 정자의 이동을 자극하였으나, 단백질 성분의 여과는 정자의 이동을 자극하는 단백질 성분의 효과를 감소시켰다. 7. 난포액으로부터 추출한 지질 성분은 정자의 이동과 운동을 유의하게 자극하지 않았다. 8. 난포액으로부터 추출된 단백질과 지질의 병용처리는 정자의 이동과 운동을 자극하는 난포액의 효과를 감소시켰다. 결론적으로 정자의 swim-up 분리에 sucrose 이중층을 이용할 수 있으며, 난포액은 sucrose 층으로부터 정자의 이동과 운동을 자극하고 수정능획득정자를 유인하였다. 특히 열내성을 가진 단백질 성분이 정자의 이동을 자극하였다.

• 대한수의학회지
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• 제32권4호
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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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• 제28권3호
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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.

• 한국임상수의학회지
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• 제25권5호
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• pp.330-339
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• 2008

세라마이드, 콜레스테롤, 자유지방산은 각질세포간 주요 지질로써 피부장벽의 생성과 유지에 있어 중요한 역할을 담당한다. 그러나, 개에서 각질세포간 지질에 대한 역할은 거의 알려져 있지 않다. 본 연구는 개에서 1.25% sodium lauryl sulphate (SLS)에 의한 피부 장벽손상 유발후 2% 세라마이드, 2%콜레스테롤, 2% 리놀레익산과 이들 세가지 지질의 혼합제 (혼합제)의 장벽손상 복구를 평가하고자 실시하였다. 피부장벽기능은 표피경유수분소실(TEWL), 피부 수화도, 피부 산도, 피부 두께 측정을 통하여 평가하였고 최종적으로 조직학적 분석과 투과 전자 현미경 (TEM)을 통하여 피부 장벽구조를 평가하였다. SLS는 개의 피부에 효과적으로 피부장벽 손상을 유발하였다. 표피경유수분소실은 세라마이드와 혼합제 적용부위에서 계면활성제 및 대조군과 비교하여 유의적인 감소를 나타내었다 (p<0.05, p<0.01). 표피경유수분소실은 12일째에 모든 지질 적용군에서 유의적으로 감소하였으나 특히 세라마이드와 혼합제에서 콜레스테롤과 리놀레익산보다 유의적으로 감소하였다 (p<0.01). 실험 기간 동안, 피부 수화도는 세라마이드와 혼합제에서 유의적 증가를 보였다 (p<0.01). 조직학적 분석에서도 각각의 지질들은 피부손상을 회복시켰다. 특히 세라마이드와 혼합제의 효과가 탁월하였고 각질층의 두께도 대조군에 비해 유의적으로 증가되었다. 피부 산도는 세라마이드, 리놀레익산, 혼합제에서 유의적으로 감소하였다 (p<0.05). 따라서 세라마이드와 혼합제의 국소적용은 계면활성제에 의한 피부 장벽 손상에 효과가 탁월함을 확인하였으며 아토피와 같은 염증성 피부염과 외부 자극에 의한 피부 장벽 손상시에도 세라마이드 또는 혼합제의 병용이 효과적일 것으로 사료된다.

• 대한화장품학회지
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• 제29권2호
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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.

• 약학회지
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• 제27권1호
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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.

• 대한화장품학회지
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• 제47권1호
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• pp.65-73
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• 2021

피부 염증은 흉터, 노화 뿐만 아니라 아토피와 같은 질환으로 발전할 수 있어 이를 조절하는 것이 매우 중요하다. 본 연구에서는 최근 인체에서 염증을 조절하는 것으로 알려진 specialized pro-resolving mediators (SPMs)의 in vitro 합성과 화장품 적용 가능성을 확인하였다. 대두의 lipoxygenase를 이용하여 mono 또는 di-hydroxy docosahexaenoic acid가 혼합된 시료 S-SPMs를 제작하였고 효능 평가에 이용하였다. 먼저, UVB로 염증을 유도한 세포에서 TNF-α와 IL-6의 발현이 S-SPMs에 의해 감소하고, 미세먼지에 의해 유도된 nitric oxide (NO)의 생성 역시 감소하는 것을 확인하여 S-SPMs의 항염 효능을 확인하였다. 또한, S-SPMs을 처리한 조건에서 malondialdehyde (MDA) 생성이 감소하여 지질 과산화 억제능이 있음을 확인하였고 S-SPMs에 의한 matrix metalloproteinase-1 (MMP-1)의 발현 감소, procollagen type I의 함량 증가를 통해 collagen 분해를 억제하고 반대로 합성은 촉진함을 확인하였다. 끝으로 filaggrin과 loricrin의 발현이 S-SPMs에 의해 증가한 것을 확인하여 피부 장벽 강화 효능을 확인하였다. 위 결과를 토대로 S-SPMs은 피부의 염증 억제와 함께 손상회복, 주름개선 및 장벽 강화를 위한 소재로 활용 가능함을 확인하였다.