• Development and Reproduction
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• v.18 no.2
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• pp.79-87
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• 2014

In Pleuronectiformes, blind-side malpigmentation (hypermelanosis) is common in cultured flatfishes, and is economically important. To understand the mechanism of blind-side hypermelanosis in flatfishes, we examined when the malpigmentation initially occurred, and studied how the symptoms proceeded during early development of the starry flounder, Platichthys stellatus. To assess quantitative pattern changes of blind-side skin, we observed morphological development of the whole body from 22 (total length [TL] $10.0{\pm}0.2$ mm and body weight [BW] $8.8{\pm}0.57$ mg) to 110 days (TL $23.4{\pm}0.7$ mm, BW $193.6{\pm}23.3$ mg) after hatching (DAH), and also examined the malpigmented area rate of blind-side skin and the malpigmented fish ratios. The experimental animals were reared in fiberglass-reinforced plastic (FRP) tanks in water at a temperature of $18.9{\pm}1.9^{\circ}C$ and salinity of $32.6{\pm}0.6$ psu and were fed with rotifer and Artemia nauplii from 22 to 48 DAH, and with A. nauplii and commercial feed from 49 to 110 DAH. As results, the first staining patch seen by the naked eye was observed around the area between the anus and pelvic fin or caudal edge of the trunk at 80 DAH (TL $20.6{\pm}0.5$ mm, BW $112.5{\pm}8.8$ mg). The pigmented area and the pigmented fish ratios were significantly increased from 80 to 110 DAH. These results indicated that malpigmentation on the blind side of starry flounder was initially observed at about 2 cm in length and 100 mg in weight, and the pigmented domain on the blind-side skin was continually broadened by the differentiation of pigmented cells (melanophores and xanthophores) with growth.

• Journal of Ginseng Research
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• v.44 no.3
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• pp.496-505
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• 2020

Background: Panax ginseng is a marvelous herbal remedy for all ailments of body. That may be why it is called Panax, which means "cure for all". Melanin is a pigment that gives color to our skin; however, increased melanin production can lead to tumor formation. Human exposure to ultraviolet B radiation has increased extensively owing to the increased sunlight due to global warming. Consequently, a phenomenon called photoaging has been observed for all skin colors and types. As a result of this phenomenon, a set of enzymes called matrix metalloproteinases, which serve as degradation enzymes for extracellular matrix proteins, mainly collagen, is increased, causing depletion of collagen and resulting in early wrinkle formation. Methods: Therefore, in our study, we used the murine melanoma cell line B16/F10 to study the inhibition of melanogenesis by Korean Red Ginseng (KRG) extract in vitro and HRM-2 hairless mice exposed to artificial ultraviolet B to examine the efficacy of KRG in vivo. We prepared a 3% red ginseng extract cream and evaluated its effects on human skin. Results: Our results demonstrated that KRG induced potent suppression of tyrosinase activity and melanin production in B16/F10 cells; moreover, it reduced the transcription and translation of components involved in the melanin production pathway. In the in vivo experiments, KRG potently suppressed the expression of matrix metalloproteinases, reduced wrinkle formation, and inhibited collagen degradation. On human skin, ginseng cream increased skin resilience and skin moisture and enhanced skin tone. Conclusion: Therefore, we conclude that KRG is an excellent skin whitening and antiaging product.

• Journal of Embryo Transfer
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• v.30 no.2
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• pp.99-107
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• 2015

The aim of the present study was to identify coat color associated genes that are differentially expressed in mature Korean brindle cattle (KBC) with different coat colors and in Hanwoo cows. KBC calves, before and after coat color appearance, were included. Total cellular RNA was isolated from the tail hair cells and used for microarray. The number of expressed coat color associated genes/probes was 5813 in mature KBC and Hanwoo cows. Among the expressed coat color associated genes/probes, 167 genes were the coat color associated genes listed in the Gene card database and 125 genes were the pigment and melanocyte genes listed in the Gene ontology_bovine database. There were 23 genes/probes commonly listed in both databases and their expressions were further studied. Out of the 23 genes/probes, MLPH, PMEL, TYR and TYRP1 genes were expressed at least two fold higher (p<0.01) levels in KBC with brindle color than either Hanwoo or KBC with brown color. TYRP1 expression was 22.96 or 19.89 fold higher (p<0.01) in KBC with brindle color than either Hanwoo or KBC with brown color, respectively, which was the biggest fold difference. The hierarchical clustering analysis indicated that MLPH, PMEL, TYR and TYRP1 were the highly expressed genes in mature cattle. There were only a few genes differentially expressed after coat color appearance in KBC calves. Studies on the regulation and mechanism of gene expression of highly expressed genes would be next steps to better understand coat color determination and to improve brindle coat color appearance in KBC.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.329-335
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• 2008

Tocopherols are essential lipophilic antioxidant in human cells, while little is known about its function in plant tissues. To study the impact of composition and content of tocopherols on stress tolerance, tobacco (Nicotiana tabacum) was transformed with a construct containing a cDNA insert encoding $\gamma$-tocopherol methyltransferase ($\gamma$-TMT/VTE4) from perilla under the control of the cauliflower mosaic virus (CaMV) 35S promoter. The transgenic tobacco was confirmed by PCR and RT-PCR. The total content and composition of tocopherols in the transgenic lines were similar with wild type controls. However, chlorophyll-a and carotenoid content in the transgenic lines were increased by up to 45% (P<0.01) and 39% (P<0.02), respectively. Also, the over-expression of $\gamma$-TMT increased the salt stress tolerance in tobacco plants. These results demonstrate that over-expression of $\gamma$-TMT gene in tocopherol bio-synthetic pathway can increase salt stress tolerance and contents of chlorophyll-a and carotenoid in transgenic tobacco plants.

• ALGAE
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• v.27 no.2
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• pp.125-134
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• 2012

Germanium dioxide ($GeO_2$) has been used for many years in the cultivation of red and green algae as a means of controlling the growth of diatoms. Brown algae are sensitive to $GeO_2$, however, the basis of this sensitivity has not been characterized. Here we use embryos of $Fucus$ $vesiculosus$ to investigate morphological and physiological impacts of $GeO_2$ toxicity. Morphometric features of embryos were measured microscopically, and physiological features were determined using pulse amplitude modulated (PAM) fluorometry. At 5 mg $L^{-1}$ $GeO_2$, embryos grew slower than controls and developed growth abnormalities. After 24 h, initial zygote divisions were often oblique rather than transverse. Rhizoids had inflated tips in $GeO_2$ and were less branched, and apical hairs were deformed, with irregularly aligned, spheroidal cells. Minimum fluorescence ($F_0$) showed minor differences over the 10 days experiment, and pigment levels (chlorophylls $a$, $c$ and total carotenoids) showed no difference after 10 days. Optimum quantum yield increased from ca. 0.52 at 24 h to 0.67 at 5 days, and $GeO_2$-treated embryos had higher mean values (significant at 3 and 5 days). Optimum quantum yield of photosystem II (${\Phi}_{PSII}$) was stable in control thalli after 5 days, but declined significantly in $GeO_2$. Addition of silica (as $SiO_2$) did not reverse the effects of $GeO_2$. These results suggest that $GeO_2$ toxicity in brown algae is associated with negative impacts at the cytological level rather than metabolic impacts associated with photosynthesis.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.693-698
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• 1992

The resistant effect of several heavy metal ions to Serratia marcescens strain P was studied by the method of minimal inhibitory concentration(MIC), and testing for their metal biosorption. S. marcescens strain P showed a good survival in the presence of high concentrations of some metal ions, namely cadmium, lead, iron, magnesium, and manganese. Copper had the most inhibitory effect among tested. The MIC value was ranged from 0.79 to 1.58 mM. Cells of S. marcescens strain P exhibit an abnormally long lag phase when incubated in high concentrations of zinc and cadmium. Pigment production was reduced by zinc and cadmium, but enhanced by lead and iron. S. marcescens strain P was resistant to ampicillin, tetracycline, cefamandole and chloramphenicol with minimal inhibitory concentration of 128 $\mu$g/ml, 32 $\mu$g/ml, 256 $\mu$g/ml, and 8 $\mu$g/ml, respectively. The kinetics study of biosorptive uptake by S. marcescens strain P revealed that 16.59% of cadmium and 35.38% of lead were eliminated from the media.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.375-380
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• 2018

We have previously found that mycelia culture broth of eight kinds of traditional herbal extracts fermented with Phellinus linteus (previously named as 8-HsPLCB) not only inhibited melanin and tyrosinase activity, but also reduced the contents of melanogenesis-related proteins, including tyrosinase and microphthalmia-associated transcription factor, in 3-isobutyl-1-methylxanthine-stimulated B16F0 melanoma cells. For a further study, the effect of 8-HsPLCB against skin pigmentation in brown guinea pigs with ultraviolet B (UVB)-induced hyperpigmentation was investigated. 8-HsPLCB (3%) and arbutin (2%) as positive controls were applied topically twice daily for 4 weeks to the hyperpigmented areas. 8-HsPLCB showed skin-lightening effect as effective as arbutin, one of the most widely used in whitening cosmetics. Melanin index values as the degree of pigmentation showed a significant reduction week by week post 8-HsPLCB treatment and then substantially reduced by 4 weeks. The degree of depigmentation after 4 weeks of topical application with 8-HsPLCB was 32.2% as compared with before treatment (0 week). Moreover, using Fontana-Masson staining and hematoxylin-eosin staining, 8-HsPLCB reduced melanin pigmentation in the basal layer of the epidermis and epidermal thickness changes exposed to the UV-B irradiation as compared with non-treatment and vehicle treatment. The intensity of the skin-lightening effect of 8-HsPLCB was similar to arbutin. These results suggest that the skin-lightening effect of 8-HsPLCB might be resulted from inhibition of melanin synthesis by tyrosinase in melanocytes. To conclude, 8-HsPLCB treatment showed reduction of the melanin pigment and histological changes induced by UV irradiation in brown guinea pigs.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.503-510
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• 2016

The accumulation (internal and superficial distribution) of magnesium ions (Mg²⁺) by the green freshwater microalga Chlorella vulgaris (C. vulgaris) was investigated under autotrophic culture in a stirred photobioreactor. The concentrations of the three forms of Mg²⁺ (dissolved, extracellular, and intracellular) were determined with atomic absorption spectroscopy during the course of C. vulgaris growth. The proportions of adsorbed (extracellular) and absorbed (intracellular) Mg²⁺ were quantified. The concentration of the most important pigment in algal cells, chlorophyll a, increased over time in proportion to the increase in the biomass concentration, indicating a constant chlorophyll/biomass ratio during the linear growth phase. The mean-average rate of Mg²⁺ uptake by C. vulgaris grown in a culture medium starting with 16 mg/l of Mg²⁺ concentration was measured. A clear relationship between the biomass concentration and the proportion of the Mg²⁺ removal from the medium was observed. Of the total Mg²⁺ present in the culture medium, 18% was adsorbed on the cell wall and 51% was absorbed by the biomass by the end of the experiment (765 h). Overall, 69% of the initial Mg²⁺ were found to be removed from the medium. This study supported the kinetic model based on a reversible first-order reaction for Mg²⁺ bioaccumulation in C. vulgaris, which was consistent with the experimental data.

• Journal of Environmental Science International
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• v.20 no.12
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• pp.1509-1519
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• 2011

The protective effect of nitric oxide (NO) on the antioxidant system under paraquat(PQ) stress was investigated in leaves of 8-week-old lettuce (Lactuca sativa L.) plants. PQ stress caused a decrease of leaf growth including leaf length, width and weight. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated PQ stress induced growth suppression. SNP permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under PQ exposure, suggesting that NO has protective effect on chloroplast membrane in lettuce leaves. Flavonoids and anthocyanin were significantly accumulated in the leaves upon PQ exposure. However, the rapid increase of these compounds was alleviated in the SNP treated leaves. PQ treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in the leaves, while SNP prevented PQ induced increase in malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that SNP serves as an antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, superoxide dismutase (SOD) and catalase (CAT) in lettuce leaves in the presence of NO donor under PQ stress were higher than those under PQ stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, to the lettuce leaves arrested SNP mediated protective effect on leaf growth, photosynthetic pigment and antioxidant systems. However, PTIO had little effect on lettuce leaves under PQ stress compared with that of PQ stress alone. The obtained data suggest that the damage caused by PQ stress is in part due to increased generation of active oxygen by maintaining increased antioxidant enzyme activities and SNP protects plants from oxidative stress. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative damage induced by PQ stress and thus confer PQ tolerance.

• Biomolecules & Therapeutics
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• v.26 no.3
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• pp.282-289
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• 2018

Melanin is a pigment produced from tyrosine in melanocytes. Although melanin has a protective role against UVB radiation-induced damage, it is also associated with the development of melanoma and darker skin tone. Tyrosinase is a key enzyme in melanin synthesis, which regulates the rate-limiting step during conversion of tyrosine into DOPA and dopaquinone. To develop effective RNA interference therapeutics, we designed a melanin siRNA pool by applying multiple prediction programs to reduce human tyrosinase levels. First, 272 siRNAs passed the target accessibility evaluation using the RNAxs program. Then we selected 34 siRNA sequences with ${\Delta}G{\geq}-34.6kcal/mol$, i-Score value ${\geq}65$, and siRNA scales score ${\leq}30$. siRNAs were designed as 19-bp RNA duplexes with an asymmetric 3' overhang at the 3' end of the antisense strand. We tested if these siRNAs effectively reduced tyrosinase gene expression using qRT-PCR and found that 17 siRNA sequences were more effective than commercially available siRNA. Three siRNAs further tested showed an effective visual color change in MNT-1 human cells without cytotoxic effects, indicating these sequences are anti-melanogenic. Our study revealed that human tyrosinase siRNAs could be efficiently designed using multiple prediction algorithms.