• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2007년도 Proceedings of The Convention
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• pp.79-92
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• 2007

Oxidative stress have known to be a risk factor for the degenerative processes and closely related to a lot of diseases. It is well established that antioxidants are good in protection and therapeutic means against oxidative damage. There is increasing interest in natural antioxidants and many natural antioxidants have been found and utilized as the possible protection for various diseases and skin aging. We have screened natural antioxidant agents for cosmeceuticals, nutraceuticals, and drugs as therapeutic and preventive means against oxidative stress, and have developed a number of novel antioxidants from various natural sources. A novel melanin synthesis inhibitor, Melanocin A, isolated from the metabolite of a fungal strain Eupenicillium shearii F80695 inhibited mushroom tyrosinase and melanin biosynthesis of B16 melanoma cells with $IC_{50}$ value of 9.0 nM and MIC value of $0.9\;{\mu}M$, respectively. Melanocin A also exhibited potent antioxidant activity by scavenging of DPPH and superoxide anion radicals. UV was found to increase the level of hydrogen peroxides and other reactive oxygen species (ROS) in skin tissues. This increase in ROS may not only alter the structure and function of many genes and proteins directly but may also modulate their expressions through signal transduction pathways and, ultimately, lead to skin damage. We investigated the effect of Melanocin A on UV-induced premature skin aging. Firstly, the effect of Melanocin A on UV-induced matrix metalloproteinase (MMP)-9 expression in an immortalized human keratinocyte cell line, HaCaT in vitro was investigated. Acute UV irradiation induced MMP-9 expression at both the mRNA and protein levels and Melanocin A suppressed this expression in a dose-dependent manner. We then investigated UV-induced skin changes in hairless mice in vivo by Melanocin A. Chronic exposure of hairless mouse dorsal skin to UV increased skin thickness and induced wrinkle formation and the gelatinase activities of MMP-2 and MMP-9. Moreover, Melanocin A significantly suppressed UV-induced morphologic skin changes and MMP-2 and MMP-9 expression. These results show that Melanocin A can prevent the harmful effects of UV that lead to skin aging. Therefore, we suggest that Melanocin A should be viewed as a potential therapeutic agent for preventing and/or treating premature skin aging. Terrein is a bioactive fungal metabolite isolated from Penicillium species. Terrein has a relatively simple structure and can be easily synthesized. However, the biologic effects of terrein are comparatively unknown. We found for the first time that terrein potently inhibit melanin production in melanocytes and has a strong hypopigmentary effect in a spontaneously immortalized mouse melanocyte cell line, Mel-Ab. Treatment of Mel-Ab cells with terrein (10-100 mM) for 4 days significantly reduced melanin levels in a dose-dependent manner. In addition, terrein at the same concentration also reduced tyrosinase activity. We then investigated whether terrein influences the extracellular signal-regulated protein kinase (ERK) pathway and the expression of microphthalmia-associated transcription factor (MITF), which is required for tyrosinase expression. Terrein was found to induce sustained ERK activation and MITF down-regulation, and luciferase assays showed that terrein inhibits MITF promoter activity in a dose-dependent manner. To elucidate the correlation between ERK pathway activation and a decreased MITF transcriptional level, PD98059, a specific inhibitor of the ERK pathway, was applied before terrain treatment and found to abrogate the terrein-induced MITF attenuation. Terrein also reduced the tyrosinase protein level for at least 72 h. These results suggest that terrain reduces melanin synthesis by reducing tyrosinase production via ERK activation, and that this is followed by MITF down-regulation.

• 한국식품영양학회지
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• 제15권2호
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• pp.137-143
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• 2002

고형분 함량은 어린 동아 착즙액에서는 3.1%, 익은 동아 착즙액에서는 0.1%를 나타냈고, 주성분은 당으로 89.7%를 나타냈다. 펙틴 함량은 익은 동아즙은 4.l1mg/ml, 어린 동아즙은 4.43mg/ml이었다. 당 함량은 익은 동아 육질은 sucrose 0,1%, glucose 0.32%, fructose 0.35%, 미확인당 1이 0.06%, 2가 0.04%로 합계 0.87%를 나타냈다. 어린 동아 육질은 sucrose 0.33%, glucose 1.04%, fructose 1.12%, 미확인당 1이 0.18%, 2가 0.12%로 합계 2.79%를 나타냈다. pH는 익은 동아는 4.64, 육질은 4.94, 어린 동아의 속은 4.96, 육질은 5.40을 나타냈다. 유기산은 익은 동아 육질에는 citric acid 0.409, magic acid 0.084, succnic acid 0.048%, 속에는 citric acid 0.648, malic acid 0.127, succinic acid 0.057%, 어린 동아 육질에는 citric acid 0.028, malic acid 0.219, succinic acid 0.298%, 속에는 citric acid 0.039, malic acid 0.360, succinic acid 0.224% 들어 있다. Fumaric acid는 미미하다. 총량은 익은 동아 속이 0.833, 어린 동아속 0.624, 어린 동아 육질 0.546, 익은 동아 육질 0.541이었다. 여드름균(Propionibacterium acnes)에 대한 항균력은 대조군이 0($\Phi$, cm)인데 반해, 비열처리 동아즙은2.6, 열처리 동아즙은2.5, 1/5 농축한 것은 1.9, 1/10 농축한 것은 2.5, 동결건조한 것은 2.3을 나타냈다. 멜라닌 생성 억제력은 0.01%에서 대조군이 29$\mu$l/m1인 데 반해 열처리 동아즙은 15$\mu$l/ml 을 나타냈고, 비열처리 동아즙은 이보다 약간 높았다. 1/5 농축한 것은 24 $\mu$l/ml, 1/10 농축한 것은 23 $\mu$l/ml, 동결건조한 것은 19 $\mu$l/ml를 나타냈다. 이들 결과에 따라 동아즙을 30% 가하여 나리싱크림과 밀크로숀을 조제하였다.