Inhibitory Effect of Ceylon Black Tea Extract on the Melanogenesis in α-MSH Stimulated B16F10 Melanoma Cells

변희국,변희국,Indira Wickramasinghec,Anuruddhika Udayangani Rathnayakea (사)한국해양바이오학회 2022 한국해양바이오학회지 Vol.14 No.1

The desire to be light skinned is universal among women. Asia has a long history of using skincare formulations as whitening agents. There is an imperative need to develop novel cosmetics from herbal sources due to several unpleasant side effects and high costs. As a result, this study aims to investigate the effect of Ceylon black tea extracts on melanogenesis. Five different Ceylon black tea extracts were prepared and examined for total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity, and tyrosinase inhibitory activity. Furthermore, B16F10 melanoma cells were treated with these extracts and tested for cytotoxicity and protein suppression levels. According to the results of this study, the highest TPCs were obtained from ethanol and acetone extractions ( 240.303 ± 1.389 μg/g and 240.202 ± 4.700 μg/g, respectively), whereas the highest TFC was obtained from acetone extraction (57.484 ± 0.413 μg/g). Ceylon black tea extracted with ethanol exhibited the highest inhibitory activity on tyrosinase with an IC50 value of 0.277 ± 0.017 mg/mL and the highest DPPH radical scavenging activity with an EC50 value of 0.009 ± 0.000 mg/mL. Furthermore, western blot results revealed that tyrosinase, TRP-1, TRP-2, and MITF protein expression levels were dose-dependently suppressed, indicating the applicability of Ceylon black tea extract as a novel melanogenesis inhibitor.

해조류의 생리활성 및 건강기능성 소재개발

변희국,김세권 한국수산경영기술연구원 2005 수산연구 Vol.22 No.-

어유의 기능성 개선 및 그 응용

변희국,김세권 한국수산경영기술연구원 2001 수산연구 Vol.15 No.-

Characterization of a New Anti-dementia β-secretase Inhibitory Peptide from Arctoscopus japonicus

변희국,김성래,박슬빛나 한국키틴키토산학회 2018 한국키틴키토산학회지 Vol.23 No.4

Amyloid plaque is a product of aggregation of β-amyloid peptide (Aβ) and is an important factor in the pathogenesis of Alzheimer’s Disease (AD). Aβ is a major component of amyloid plaque and vascular deposits in the AD brain. The enzyme β- secretase is required for the production of Aβ; thus, prevention of the formation of Aβ through the inhibition of β-secretase is a major focus in the study of the treatment of AD. In this study, we investigated β-secretase inhibitory activity of an Arctoscopus japonicus peptide. An Alcalase hydrolysate had the highest β-secretase inhibitory activity. A β-secretase inhibitory activity peptide was separated using ion exchange column chromatography (carboxy-methyl: CM, quaternary methyl ammonium: QMA) and reverse phase high performance liquid chromatography (RP-HPLC) on a C18 column. The IC50 value of the purified peptide was 248.2±1.73 μg/mL. The β-secretase inhibitory peptide was identified as a six amino acid residue of Gly-Pro-Val-Gly-Ala- Pro (MW: 497.27 Da). In cell viability experiments, the final purified fraction, the carboxy-methyl ion exchange column fraction (CM-F1) showed no significant cytotoxic effect in SH−SY5Y cells at concentrations below 100 μg/mL in 24 h. The results of this study suggest that peptides separated from Arctoscopus japonicus may be beneficial as β-secretase inhibitor compounds in functional foods.

키틴 및 키토산 유도체의 합성과 그 물리화학적 특성

변희국 부산수산대학교 생명과학연구소 1993 生命科學硏究報告 Vol.4 No.-

한외여과막 반응기에서 단백질의 막 투과특성

변희국,전유진,김세권 한국막학회 1998 멤브레인 Vol.8 No.1

한외여과막 반응기에서 gelatin 및 bovine serum albumin(BSA) 용액을 한외여과막(MWCO 5,000)으로 여과시 작동시간, pH, 온도, 농도 및 단백질 가수분해 효소의 첨가가 투과유속에 미치는 영향에 대하여 검토하였다. 한외여과막 반응기의 작동시간에 따른 gelatin 용액의 투과유속은 작동시간 20분까지 약간 감소하다가 그 이후에는 18.9l/m2· hr로 거의 일정하게 유지되었으며, BSA 용액은 작동시간 40분까지 완만하게 감소하다가 그후 6.4l/m2· hr로 초기유속의 66%가 감소하였다. 온도에 따른 gelatin 용액의 투과유속은 온도가 올라감에 따라 비례적으로 증가하였다. BSA 용액은 60℃에서 투과유속이 가장 높았으며, 30~50℃ 범위에서는 온도의 영향을 받지 않았다. pH 변화에 따른 gelatin 및 BSA 용액의 투과유속은 10psi 이상에서 각각의 등전점 영역인 pH 5.0에서 가장 낮았다. 투과압력 30psi에서 1% 및 6%(w/v) gelatin용액의 투과유속은 각각 43.0l/m2· hr 및 13.5l/m2· hr 였으며, BSA 용액의 경우는 1% 및 4%에서 33.0l/m2· hr 및 14.0l/m2· hr로 농도가 증가됨에 따라 각각 68.6% 및 57.6% 감소하였다. Gelatin 및 BSA 용액에 단백질 가수분해효소의 첨가에 의한 투과유속은 gelatin 및 BSA의 저분자화에 의한 점도의 감소로 효소를 첨가하지 않은 것보다 30% 향상되었다. Effects of operating time, pH, temperature, concentration and addition of proteolytic enzyme on permeate flux for the ultrafiltration of gelatin and bovine serum albumin(BSA) solutions were studied. The results showed that permeate flux of gelatin solution was maintained almost constant during the operating time, and that of BSA solution was decreased to 66% of the initial value after 40 min operation. The permeate flux of gelatin solution was increased by increasing temperature. The permeate flux of BSA solution was constant in the temperature range of 30~50℃, but increased at 60℃.. The permeate fluxes of gelatin and BSA solution showed minimum values near the isoelectric point of pH 5.0. The permeate fluxes of 1%(w/v) and 6% gelatin solution were 43.0l/m2· hr and 13.5l/m2· hr, respectively. Those of 1% and 4% BSA solution were 33.0l/m2· hr and 14.0l/m2· hr, respectively. The permeate fluxes of gelatin and BSA solutions were decreased to 68.6% and 57.6% of their initial values by increasing their concentration, respectively. The permeate fluxes of gelatin and BSA solutions were enhanced by 30% with the addition of proteolytic enzyme.

Chlorella Ethanol Extract Induced Phase II Enzyme Through NFE2L2 (Nuclear Factor [Erythroid-Derived] 2-Like 2, NRF2) Activation and Protected Ethanol-Induced Hepatoxicity

변희국,이정권 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.2

In this study, we investigated the hepatoprotective effects of ethanol extracts from Chlorella vulgaris (CH) on animals. We measured its effect on the quinone reductase (QR) activity in Hepa1c1c7 cells, finding that CH induced a significantly higher QR activity in these cells. We isolated the active fraction (CH F4-2) from CH using chromatography methods. CH F4-2 may activate cellular antioxidant enzymes through upregulation of the Nrf2 pathway in hepatocarcinoma cells with CH F4-2 (25.0–200 μg/mL) for 48 h. Furthermore, CH F4-2 increased the expression of NQO1 [NAD(P)H: quinone oxidoreductase, also known as QR], heme oxygenase-1, and glutathione-S-transferase P. Moreover, we found that ethanolinduced hepatic pathological changes—elevations in glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, γ-glutamyltransferase, and lactate dehydrogenase—were significantly decreased. The inhibitory effect of CH on alcohol-induced liver injury was associated with the suppression of alcohol-induced increases in intestinal permeability. The ethanol extract from CH was found to induce QR activation, making it a potentially good candidate for a hepatoprotection agent.

[산ㆍ학ㆍ연 논단] 해양바이오 산업의 동향 및 전망

변희국(Hee-Guk Byun),김세권(Se-Kwon Kim) 한국식품영양과학회 2005 식품산업과 영양 Vol.10 No.2

학술발표 : 생물공학분야 / 포스터발표 ; Emulsifying Property of Carboxymethylchitin

변희국(Hee Guk Byun),박표잠(Pyo Jam Park),김세권(Se Kwon Kim) 한국국제경제학회 2001 한국국제경제학회 학술대회발표 논문집 Vol.2011 No.3

Carboxymethylchitin 을 이용한 에멀젼의 제조 및 특성

변희국(Hee Guk Byun),박표잠(Pyo Jam Park),김세권(Se Kwon Kim) 한국키틴키토산학회 2001 한국키틴키토산학회지 Vol.6 No.3

본 연구에서는 키틴의 기능성을 개선하고자 화학적 합성법에 의해 카르복시메틸키틴을 합성하였으며, 카르복시메틸키틴으로 에멀젼을 제조할 때의 농도, 물과 대두유의 혼합비, pH 및 온도의 최적조건을 유화성으로서 측정하였다. 카르복시메틸키틴의 유화성은 젤라틴, 알부인 및 Tween-80보다 약 20%유화성이 높았다. 카르복시메틸키틴을 이용한 에멀젼의 최적제조조건은 농도 1%(w/v), 물과 대두유의 혼합비 50%, pH 8.0 및 온도 20℃ 였으며 , 이들 조건하에서 유화성은 86%였다. 또한 카르복시메릴키틴의 유화안정성은 젤라틴, 알부민 및 Tween-80보다 높게 나타났다. 이것은 각 유화액의 현미경 관찰에서 카르복시메틸키린으로 만든 유화입자의 크기가 ~10 ym 이하로 가장 작고 조밀성이 높은 것으로도 알 수 있었다. To improve the functional properties of chitin, carboxymethylchitin (CM-chitin) was synthesized by chemical modifications. Emulsifying activity of the CM-chitin was investigated in various conditions such as concentration, water-oil ratios, pH and temperature. The emulsifying activity of CM-chitin was 20% higher than that of gelatin, bovine serum albumin, and Tween-80 as commercial emulsifier. The emulsifying activity of CM-chitin solution was the highest at 1%, and was decreased with increasing concentration at above 1 % of CM-chitin. The optimum conditions of water-oil ratios, pH and temperature were 50% (w/v), pH 8.0 and 20℃, respectively. In these conditions, the emulsifying activity of CM-chitin solution was 86%. The emulsion stability of CM-chitin was higher than that of other commercial emulsifier. The emulsifier structure was observed with the characters of high density and small particles size (~ 10 ym).