• Biomolecules & Therapeutics
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• 제32권4호
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• pp.492-498
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• 2024

Bioassay and HPLC-UV guided fractionations of the crude extract of marine-derived Streptomyces sp. SNA-077 have led to the isolation of a red pigment, undecylprodigiosin (1). The chemical structure of undecylprodigiosin (1) was revealed by the interpretation of NMR and mass spectroscopic (MS) data. Further, anti-melanogenic effects of undecylprodigiosin (1) were investigated. First, the melanin contents of undecylprodigiosin (1)-treated B16 cells were evaluated. Furthermore, undecylprodigiosin (1) significantly inhibited the key enzymes involved in melanogenesis, including tyrosinase, tyrosinase related protein-1 (TYRP-1), and dopachrome tautomerase (DCT). The mRNA and protein expression levels of Microphthalmia-associated transcriptian factor (MiTF), a critical transcription factor for tyrosinase gene expression, were also suppressed by undecylprodigiosin (1) treatment in B16 analyses. Collectively, our results suggest for the first time that undecylprodigiosin (1), a potent component isolated from an extract of marine Streptomyces sp. SNA-077, critically exerts the anti-melanogenic ability for melanin synthesis.

• KSBB Journal
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• 제29권5호
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• pp.343-352
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• 2014

In the present study, antioxidant activities of two crude pigments (acetone and MeOH) and their solvent fractions (n-hexane, 85% aq.MeOH, n-BuOH, and water fractions) from red crab shell were evaluated by measuring 1,1-diphenyl-2-picryl hydrazyl (DPPH), peroxynitrites, and degree of production of reactive oxygen species (ROS) in HT 1080 cells as well as the extent of oxidative damage of genomic DNA purified from HT 1080 cells. From comparative analysis, 85% aq.MeOH fraction showed the strongest scavenging effect on both peroxynitrite in vitro and intracellular ROS in HT 1080 cells. Protective activities of these samples against hydroxyl radical-mediated genomic DNA damage were also investigated. 85% aq.MeOH and n-BuOH fractions significantly inhibited oxidative damage of purified genomic DNA. On the other hand, we investigated their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated Raw 264.7 cells. All samples significantly reduced NO production. Among the samples, n-hexane and water solvent fractions most effectively inhibited NO.

• 식물조직배양학회지
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• 제22권2호
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• pp.59-64
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• 1995

포도의 현탁배양계에서 안토시안닌 색소의 축적에 미치는 salicylic acid (SA)의 영향을 알아보기 위하여 다양한 농도의 SA를 계대배양시에 함께 처리한 결과 1 $\mu$M 이하의 낮은 농도에서는 세포의 생장 및 색소의 축적에 있어서 어떤 영향을 미치지 않았다. 그러나, 5 $\mu$M와 10 $\mu$M의 농도에서는 세포의 생장은 일시적으로 억제되지만 색소의 축적은 크게 증가한다. 또한 20 $\mu$M의 고농도에서는 세포의 생장은 완전히 억제되어 세포가 죽기까지 하는 결과를 나타내었다. 암배양 상태의 세포서도 SA을 처리해 주면, 암배양에 의한 안토시아닌 색소 생합성능의 저하는 회복되어, SA처리없이 광처리만 해준 세포보다도 더 높은 색소의 축적을 보였다. 5 $\mu$M의 SA를 계대배양후 시일별로 처리한 결과, 처리후 24 시간 이후에 급격한 색소의 축적을 나타내었지만 계대배양 후 2일째에 처리한 세포에서 가장 높은 색소의 축적를 보였으며, 처리후 5일째가 되면 SA는 무처리구의 암배양세포(7일째 세포)에 비해 4배 이상의 색소의 축적을 보였다.

• 생약학회지
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• 제51권2호
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• pp.131-138
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• 2020

Ultraviolet (UV)-induced damage plays a major role in ocular diseases, such as cataracts and retinal degeneration. UV irradiation can generate free radicals including reactive oxygen species (ROS), which are known to cause lipid peroxidation of cellular membranes. It has also been shown that UV can damage DNA directly and induce apoptosis. Rhynchosia volubilis Loureiro (the small black bean or yak-kong, RV) and Beta bulgaris (beet, BB) are used as health supplements. In this study, we explored the protective effects of RV and BB against UVA-induced damage in human pigment epithelial (ARPE-19) cells and in mice. RV and BB mixture and their effective constituents (cyanidin, delphidin, petunidin glycosides) improved cell viability and suppressed intracelluar ROS generation. Phosphorylation of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), Erk1/2 was analyzed by immunoblotting. RV and BB mixture inhibited UVA-induced phosphorylation of p38 MAPK, JNK, Erk1/2 in APRE-19 cells. RV and BB treatment also showed protective effects on ocular damage in UVA-irradiated mice by increasing the levels of endogenous antioxidants such as superoxide dismutase and glutathione. RV and BB have the potential to be used in a range of ocular diseases and conditions, based on in vitro and in vivo study.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.544-551
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• 2003

Interactive effects of UV-B and Cd on growth, pigment, photosynthesis, and lipid peroxidation have been studied in Anabaena, Microcystis, and Nostoc; all the tested cyanobacteria showed differential sensitivity to different dosage of UV-B and Cd alone as well as in combination. Phycocyanin was severely affected by UV-B and Cd by all the strains; the degree of pigment bleaching was most pronounced in Anabaena followed by Microcystis and Nostoc. $UV-B_2+Cd_2$ produced nearly 83, 78, and 65% inhibition of phycocyanin in Anabaena, Microcystis, and Nostoc, respectively. The above treatment also significantly decreased the contents of Chl ${\alpha}$ and carotenoid. Presence of capsule in Microcystis protected the phycocyanin bleaching as compared to decapsulated cells. Laboratory-grown Microcystis revealed about 75 and 80% inhibition, following $UV-B_2+Cd_2$ treatment, respectively. in capsulated and decapsulated cells. Damage caused by Cd was more pronounced than UV-B. Inhibition of photosynthesis did occur in all the test strains, being maximum in Anabaena. PS II was the most sensitive component of the electron transport chain, showing 84, 80, and 70% inhibition in Anabaena, Microcystis, and Nostoc, respectively. As compared to control, significant lipid peroxidation (6.5-fold higher) was observed in Anabaena with $UV-B_2+Cd_2$, $^{14}C-uptake$ was more susceptible to Cd and Uv-B than oxygen-evolution. Approximately 84, 80, and 76% inhibition of $^{14}C-uptake$ was observed in Anabaena, Microcystis, and Nostoc, respectively. Similarly, $UV-B_2+Cd_2$ inhibited APT content of Anabaena by 87%. This ,study suggests that inhibition of carbon fixation was due to decreased ATP content of the test cyanobacteria by UV-B+Cd, where Anabaena was the most sensitive and Nostoc the most tolerant.

• Molecules and Cells
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• 제46권11호
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• pp.675-687
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• 2023

Accumulation of pathogenic amyloid-β disrupts the tight junction of retinal pigment epithelium (RPE), one of its senescence-like structural alterations. In the clearance of amyloid-β, the autophagy-lysosome pathway plays the crucial role. In this context, mammalian target of rapamycin (mTOR) inhibits the process of autophagy and lysosomal degradation, acting as a potential therapeutic target for age-associated disorders. However, efficacy of targeting mTOR to treat age-related macular degeneration remains largely elusive. Here, we validated the therapeutic efficacy of the mTOR inhibitors, Torin and PP242, in clearing amyloid-β by inducing the autophagy-lysosome pathway in a mouse model with pathogenic amyloid-β with tight junction disruption of RPE, which is evident in dry age-related macular degeneration. High concentration of amyloid-β oligomers induced autophagy-lysosome pathway impairment accompanied by the accumulation of p62 and decreased lysosomal activity in RPE cells. However, Torin and PP242 treatment restored the lysosomal activity via activation of LAMP2 and facilitated the clearance of amyloid-β in vitro and in vivo. Furthermore, clearance of amyloid-β by Torin and PP242 ameliorated the tight junction disruption of RPE in vivo. Overall, our findings suggest mTOR inhibition as a new therapeutic strategy for the restoration of tight junctions in age-related macular degeneration.

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.329-340
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• 2024

Mangiferin is a kind of natural xanthone glycosides and is known to have various pharmacological activities. However, since the beneficial efficacy of this compound has not been reported in retinal pigment epithelial (RPE) cells, this study aimed to evaluate whether mangiferin could protect human RPE ARPE-19 cells from oxidative injury mimicked by hydrogen peroxide (H₂O₂). The results showed that mangiferin attenuated H₂O₂-induced cell viability reduction and DNA damage, while inhibiting reactive oxygen species (ROS) production and preserving diminished glutathione (GSH). Mangiferin also antagonized H₂O₂-induced inhibition of the expression and activity of antioxidant enzymes such as manganese superoxide dismutase and GSH peroxidase, which was associated with inhibition of mitochondrial ROS production. In addition, mangiferin protected ARPE-19 cells from H₂O₂-induced apoptosis by increasing the Bcl-2/Bax ratio, decreasing caspase-3 activation, and blocking poly(ADP-ribose) polymerase cleavage. Moreover, mangiferin suppressed the release of cytochrome c into the cytosol, which was achieved by interfering with mitochondrial membrane disruption. Furthermore, mangiferin increased the expression and activity of heme oxygenase-1 (HO-1) and nuclear factor-erythroid-2 related factor 2 (Nrf2). However, the inhibition of ROS production, cytoprotective and anti-apoptotic effects of mangiferin were significantly attenuated by the HO-1 inhibitor, indicating that mangiferin promoted Nrf2-mediated HO-1 activity to prevent ARPE-19 cells from oxidative injury. The results of this study suggest that mangiferin, as an Nrf2 activator, has potent ROS scavenging activity and may have the potential to protect oxidative stress-mediated ocular diseases.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.181-185
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• 2002

The melanotic neuroectodermal tumor of infancy is a rare neoplasm arising in the first year of life. A 33-day-old female infant had an enlarged alveolar ridge on the right anterior maxilla. Intraoral examination revealed a nonulcerative swelling at the site. An intraoral radiograph showed an ill-defined radiolucency on the right anterior maxilla and displacement of primary incisors from their alveolar sockets. CT scans revealed an expansion of the surrounding bone and partial destruction of the anterior wall of the premaxilla. Histopathologic examination showed the cytoplasm of neuroblastic cells and eosinophilic, epithelioid cells frequently contained a dark brown granular pigment that stained positively to vimentin and HMB45, focally positive to NSE and cytokeratin. Four weeks after the operation, CT scans showed a rapidly growing soft tissue mass occupying right maxillary sinus encroaching to the orbit and nasal cavity. The final diagnosis was made as a malignant melanotic neuroectodermal tumor of infancy.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.391.3-392
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• 2002

Melanin is a main pigment found in skin. hair and eyes, and tyrosinase plays an important role in the process of melanin polymer biosynthesis. Caesalpinia sappan L.(C. sappan) has been commonly used in Oriental folk medicines to promote blood circulation and as analgesic as well as remedy for thrombosis. This present study was designed to investigate the effect of ethyl acetate extract from C. sappan on melanogenesis in Melan-a cells. (omitted)

• 미생물과산업
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• 제26권1호
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• pp.8-17
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• 2000

Aspergillus을 이용하여 생리적 제 성질을 조사하였던 바 다음과 같은 결론을 얻었다. 1)각 균주들은 각각 그들의 특성을 가지고 있었으며 이로서 균동정의 가능성을 나타내었다. 2)Amylase측정결과에서 보면 비교적 역가가 높은 균주들이 관찰되었으며, 이는 일주간의 배양시간의 경과에 따라 역가가 증가하였으나 protease의 역가는 우수한 균주를 발견키가 어려웠다. Iodine의 착색대와 비착색대의 비율에 의한 역가의 정성적인 측정이 가능하였다.