Se-Young Choung has completed his PhD at the age of 31 years from Tokyo University. He is a professor of Kyung Hee University College of Pharmacy. He has published more than 60 papers in reputed journals and has been serving as a president of repute in Korea Accreditation Council for Pharmacy Education. He is interested in development of natural product-derived drug and health functional food. (e.g. skin beauty, protection of eye degeneration, and improvement of embolic syndrome)
Melanin protects the skin from UV-induced damage. However, excessive melanin biosynthesis induces hyperpigmentation which can result in pigmentary disorders, such as freckles, moles, and senile lentigines. Oyster hydrolysate(OH) was reported to have antioxidative peptides, and some of the antioxidants downregulate melanogenesis. Therefore, we hypothesized that OH downregulates melanogenesis. To investigate the inhibitory effect of OH on melanin biosynthesis in C57BL/6J mice, hyperpigmentation was induced by UVB irradiation for 10 days. Then the mice were orally administered OH or ascorbic acid (positive control) for 9 weeks. At 3, 6, and 9 weeks, we sacrificed the mice and assessed the inhibitory effect of OH on melanin biosynthesis in the ears by DOPA and Fontana-Masson staining. The number of melanocytes and the distribution of melanin granules were dose-dependently decreased in DOPA and Fontana-Masson staining of the mice treated with OH. Furthermore, we investigated the inhibitory mechanisms of OH on melanin biosynthesis. MITF regulates tyrosinase which is the rate-limiting enzyme. Three melanocyte-specific enzymes (e.g. tyrosinase, TRP-1, and TRP-2) catalyze the reaction that tyrosine is converted into melanin pigments. To determine whether OH inhibits the melanin biosynthesis, we detected the protein expressions of MITF, tyrosinase, TRP-1, and TRP-2 using western blot analysis. We found that OH downregulated the protein expressions of MITF, tyrosinase, TRP-1, and TRP-2 which were increased by UVB irradiation. These results elucidated that OH may be promising as an anti-melanogenic component, and further investigations should be performed regarding its potential as a whitening agent.
Kazuki Oguri completed his PhD from Osaka University at the age of 29 years on March 22, 2017. He got a license for Japanese pharmacist at 2013. His research focuses on longgu; one of the crude drugs using in Kampo medicine (traditional Japanese medicine). He has published three papers in journals.
Longgu (Ryu-kotsu, Fossilia Ossis Mastodii, Os Draconis, or dragon bone) is the only fossil crude drug listed in the Japanese Pharmacopoeia, which defined as “the ossified bone of large mammal.” It is used as sedative component in Keishikaryukotsuboreito (KRB) formula in Kampo medicine (traditional Japanese medicine). In Japan, all longgu is purchased from People’s Republic of China. Longgu resources are facing the threat of depletion. Effective countermeasures are urgently required. However, information is insufficient about role of longgu in Kampo formulas. We investigated the significance of longgu in KRB formula, which comprises seven crude drugs. We analyzed the components in KRB decoction using inductively coupled plasma mass spectrometry and gas chromatography. Slight inorganic components and no organic ones were detected from single decoction of longgu. The organic component profile of KRB decoction is different from that of longgu-free KRB decoction. The result of scanning electron microscopy with energy dispersive X-ray spectroscopy showed that decocted longgu captured organic materials at its uneven surface with small pores. We hypothesized that longgu adsorbs the components on its surface. The decocted longgu were submitted into solid state NMR and nitrogen adsorption measurements. The results of them showed that KRB-decocted longgu had smaller water content and specific surface area than raw and single decocted longgu, respectively. These results supported our hypothesis. We suggest recycling of longgu as one of the countermeasure for depletion though development of purging methods is needed.