• Journal of Life Science
• /
• v.33 no.2
• /
• pp.169-175
• /
• 2023

As a protective defensive mechanism against ultraviolet (UV) light exposure in skin tissue, melanocytes produce the pigment melanin. Tyrosinase plays a key role in melanin production in melanocytes. However, the overproduction of melanin can lead to lesions, such as freckles and dark spots. Thus, it is clinically important to find a modulating molecule to control melanogenesis by regulating tyrosinase expression and/or activity. It is known that catechin, a plant flavonoid, can reduce melano- genesis through the downregulation of tyrosinase expression. Here, we tested whether catechin derivatives isolated from the stem bark of Ulmus parvifolia have an effect on melanin production by regulating tyrosinase in mouse melanoma cells and in vitro mushroom tyrosinase. The catechin derivatives used in this study included C5A, C7A, C7G, and C7X. Treatments using these catechin derivatives reduced melanin production in mouse melanoma B16F10 cells in which melanogenesis was stimulated by α-MSH. Notably, the anti-melanogenic effects of catechin derivatives were similar to those of kojic acid, a well-known anti-melanogenic molecule. Both C5A and C7A directly inhibited the activity of tyrosinase isolated from mushrooms in vitro. Furthermore, our in silico computational simulation showed that these two compounds were expected to bind to the active site of tyrosinase, which is similar to kojic acid. In addition, all four catechin derivatives reduced tyrosinase protein expression. In summary, our results showed that catechin derivatives can reduce melanogenesis by regulating tyrosinase activity or expression. Thus, this study suggests that catechin derivatives isolated from U. parvifolia can be novel modulators of melanin production.

• The Korean Journal of Ecology
• /
• v.26 no.5
• /
• pp.273-280
• /
• 2003

Saline conditions invoke oxidative stress attributed to the overproduction of reactive oxygen species (ROS). Changes in quantum efficiency and antioxidative enzyme activity upon salt treatment were examined in a salt-tolerant plant, Atriplex gmelini, to test the hypothesis that salt tolerance of A. gmelini is due to the increased activity of antioxidative enzymes. A. gmelini showed optimum growth at 100 mM NaCl producing 116% of the shoot dry weight over control plants in 0 mM NaCl treatment. Healthy growth persisted up to 300 mM NaCl treatment maintaining normal internal water content and dry weight. No photochemical stress or damages on antioxidative defense system was obvious in plants of 2 and 4 day salt treatment which was indicated by increased quantum efficiency (Fv/Fm value), decreased stress index (Fo/Fm value), and increased activity of antioxidative enzymes such as SOD, APX, GR. However, the plants treated with 400 mM NaCl showed decrease in growth and in antioxidative enzyme activity although the enzyme activity was still higher than that of the 0 mM NaCl treated plants (l31%, 114%, and 134% of the SOD, APX, and GR activity, respectively). Interestingly, another important antioridative enzyme that scavenges H₂O₂ in plant cells, CAT, showed rapid decrease in its activity as salt concentration increased; 38%, 22%, 15% of the 0 mM NaCl treated plants at 200, 300, 400 mM NaCl treatments, respectively. It appears that the enzymes in ascorbate-glutathione cycle such as APX and GR play the major roles in scavenging ROS produced by salt stress in A. gmelini. After 6 days of salt treatment, the damage in photochemical and antioxidative defense system was indicated by decreased Fv/Fm value and increased Fo/Fm value. A. gmelini appears to cope with short term salt treatment by enhanced activity of the antioxidative defense system, whereas long term stress invoke oxidative stress by increased ROS due to the damages in photochemical and antioxidative system.

• Korean Journal of Food Science and Technology
• /
• v.41 no.6
• /
• pp.673-680
• /
• 2009

This study was conducted to screen for plant food materials that improve human intestinal microflora, especially microorganisms associated with obesity. Among 30 tested plant food materials, the extract of Schizandra chinensis inactivated Eubacterium limosum, Bacteroides fragilis and Clostridium spp. Additionally, S. chinensis extract was also found to have a growth-promoting effect on Bifidobacterium spp.. The antimicrobial activity and antioxidant activity of the water extract did not decrease in respond to heating. Additionally, the water extract of S. chinensis did not show a toxic effect on the growth of Caco-2 cells. In vivo feeding tests were performed to investigate the influence of extract on the intestinal microflora in rats. Although the extract did not reduce obesity induced by a high fat diet, it led to significant increase in the population of Bifidobacterium spp. and a decrease in the population of Clostridium spp. in rats. Taken together, these results indicate that S. chinensis could be useful as a functional food component to control intestinal microbial flora.

• Korean Journal of Environmental Agriculture
• /
• v.5 no.2
• /
• pp.141-148
• /
• 1986

The blue-light effect on the grown as well as on the physiological activity of some major horticultural plants in Korea has been investigated. The light quality used for the work was obtained from sunlight filtered by an orangecolored polyethylene film which removed about 70% of visible light in the spectral region of $350㎚{\sim}500㎚$. The film was developed in this laboratory especially for the work and named BCR film meaning blue color-removing film. The light environment in the plastic house which was built with BCR film provided plants with the blue color-deficient sunlight. Thus, the photobiological effect of blue light could be examined conversely by comparing with the effect of white sunlight in a conventional plastic house built with colorless polyethylene film. In a sense of applicability to horticulture, two remarkable effects of the blue color-deficient sunlight on plant physiology were observed: First, it enhanced to a great extent the growth activity of plants-pepper, cucumber, zucchini, tomato, and leaf lettuce at the vegetative stage as well as at the reproductive stage, as demonstrated by their yield which were in average $40{\sim}50%$ increased compared with the control (under white sunlight). Second, it improved significantly the cold tolerance of plants, as exhibited with their resistance to chilling during treatment in a cold chamber maintained at a temperature which caused chilling injury to the plants of control. The visualized effects were reflected on the physiological activity of cells on organelle level. Chloroplast isolated from the plant leaves grown under BCR film showed considerably stronger photosynthetic activity, as judged by the increased electron transport rate of illuminated chloroplast, than that from leaves grown under white PE film. Mitochondria from leaves grown under BCR film maintained normal respiration activity until temperature decreased to a few degree($^{\circ}C$) lower than the temperature which caused respiratory inhibition to mitochondria obtained from leaves of the control.

• Korean journal of applied entomology
• /
• v.59 no.1
• /
• pp.25-35
• /
• 2020

The striped fruit fly, Zeugodacus scutellata, is endemic in Korea, but it has been regarded as one of the serious quarantine pests throughout the world. Sterile insect release technique (SIT) has been used to eradicate quarantine fruit flies. This study developed a technique to generate sterile males and applied SIT to control Z. scutellata. First of all, the reproductive systems of Z. scutellata adults were examined with fluorescent microscope. Polytrophic ovaries comprises of around 100 follicles with developing oocytes. Each follicle contains an oocyte with several nurse cells and are surrounded with follicular epithelium. Oocyte development began at 10 days after adult emergence (DAE) and formed chorionated oocytes after 20 DAE. On the other hand, male testes were well developed just after adult emergence. The vas deferens was filled with motile sperms. To generate sterile males, different doses (0~1,000 Gy) doses of electron beam were irradiated to 3~5 days old pupae of Z. scutellata. When male pupae were irradiated with electron beam at 200 Gy, they developed and mated with females without any significant difference compared to untreated males. Although the untreated females mated with the 200 Gy-irradiated males laid eggs, no eggs did not hatch. The 200 Gy-irradiated males were then applied to untreated male and female flies in a density ratio of 1:9 (untreated males : treated males). The laid eggs suffered significant infertility. These results suggest that electron beam-irradiated pupae at 200 Gy resulted in male sterility and the resulting males would be applied to SIT.

• Journal of Bio-Environment Control
• /
• v.4 no.1
• /
• pp.50-58
• /
• 1995

These studies were carried out to develop a system for non -destructive and continuous measurement of fresh weight and to analyse the growth response of leaf lettuce under the different nutrient solution and light condition with this system. The developed measurement system was consisted of four load cells and a microcomputer. The output from the system was highly positive correlation with the plant fresh weight above the surface of the hydroponic solution. The top fresh weight of plant could be measured within the error $\pm$ 1.0g in the range of 0 - 2000g. The top fresh weight of leaf lettuce increased 44 times at 18th day after transferring to the nutrient solution, and the maximum growth rate was observed at 13th day after transferring. The growth rate was 10.7- 29.6% per day during 18 days. Optimum concentration of the nutrient solution for the growth of lettuce was 1.4 - 2.2 mS/cm of EC level. When the light condition was changed from dark to light, the fresh weight was temporarily decreased, but the fresh weight increased under the opposite condition. Top fresh weight of leaf lettuce in the darkness normally increased within 12 hours after darkness treatment, and then slowly increased until 78 hours under continuous dark condition. After that times, the fresh weight began to decrease.

• Korean Journal of Plant Taxonomy
• /
• v.39 no.1
• /
• pp.12-23
• /
• 2009

To verify hybridity of Asplenium castaneo-viride, external morphology, spore morphology, anatomy and chromosomes of the species and of the two presumed parental species, A. incisum and A. ruprechtii, were examined. A. castaneo-viride usually had 1-pinnately divided frond. However, some individuals had almost simple fronds with pinnatisect basal parts similar to A. ruprechtii, while others had fronds similar to A. incisum in having oblanceolate blades and basal pinnae with triangular, 2-3 lobed apices. On the surface of the spores, sculpturing consisted of folds that were usually prominent; forming long wings, and irregular or incomplete reticulation. However, reticulation patterns varied among species. A. castaneo-viride showed a wide range of variation from sparse to dense patterns, whereas A. incisum showed only from sparse to intermediate patterns. A. ruprechtii showed from intermediate to dense patterns. The spore size of A. castaneo-viride was $54.63{\mu}m$, larger than other two species ($47.81{\mu}m$ in A. incisum and $44.22{\mu}m$ in A. ruprechtii). The level of undulation of epidermal cell wall was also different. A. incisum had the most shallowly undulated wall, and A. castaneo-viride had a pattern intermediate between the two presumed parental species. This same patterns was recognized in the density of stomata. The density of $45.91/mm^2$ in A. castaneo-viride was intermediate between the two presumed parental species ($67.00/mm^2$ in A. incisum, and $37.86/mm^2$ in A. ruprechtii). Chromosome number was constant (2x =2n = 72) as in A. incisum and A. ruprechtii. However, A. castaneo-viride showed a different ploidy level. The populations of Mt. Mai (Jeonbuk province) and Mt. Duryun (Jeonnam province) were diploid (2n = 72) which is a new record for this taxon, whereas the population of Mt. Buram (Seoul) was tetraploid (2n = 144). Conclusively, A. castaneo-viride was revealed to be a hybrid of A. ruprechtii and A. incisum based on evidence involving leaves, spores, epidermal cells, stomata and chromosome number.

• Journal of Plant Biotechnology
• /
• v.34 no.4
• /
• pp.331-338
• /
• 2007

One-node stem pieces ca. 1 cm in length containing a axillary bud and a fully expanded leaf were obtained from it in vitro plants of potato (Solanum tuberosum L.). Leaves were removed and the nodes were cultured on the MS medium to investigate the effects of temperature, day length, sucrose, and CCC in microtuber formation and development. The fresh weight of microtubers after 80 days increased significantly at 8% sucrose and $20^{\circ}C$ compared with $28^{\circ}C$. The tuberization and development were reduced at $28^{\circ}C$ except short-day treatment of 8 hours at 8% sucrose. The fresh weight and diameter were increased on the culture medium added CCC 500 mg/L. The potato tuberization was promoted under short daylength, and it showed great effect by treatment with the CCC. Though the tuberization was promoted at low temperature of $20^{\circ}C$ in a histologic change of an axillary bud part cell of a potato, the cells were able to observe the swelling growth. Swelling growth of tissue was stimulated in the darkness and was more remarkable by addition of CCC. In particular, in the visual ratio of cell division for each position in the tissue, the cortex part showed larger ratio of cell expansion than that of the pith part. The effect of CCC was identified at 8% sucrose in the darkness. The effect of CCC was not showed in sucrose 3% under long daylength of 16 hours. As a result, the fact of a substance with AGPase important for starch composition was certified by the result with the inclose of AGPase activity on high concentration of sucrose, CCC, and dark treatment by which tuber formation and development are promoted.

• Korean Journal of Plant Resources
• /
• v.26 no.4
• /
• pp.441-449
• /
• 2013

This study was conducted to select some useful plants as functional material candidates. A total of 38 plants were preliminarily screened for the anti-inflammatory and antioxidant activities. The preliminarily selected 8 plants were further investigated to verify the in vitro inhibitory effect on inflammation and oxidative stress. Boehmeria platanifolia (root), Carpinus coreana (branch), and Eupatorium japonicum (leaf) inhibited the expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-treated RAW 264.7 cells. Eupatorium japonicum (leaf) suppressed the expression of cyclooxygenase-2 (COX-2), whereas Boehmeria platanifolia (root) and Prunus yedoensis (branch) inhibited the transcription of nuclear factor-kappa B (NF-${\kappa}B$). Treatment with the extracts ($2.5{\sim}20{\mu}g/ml$) of Abutilon theophrasti (leaf, flower/seed) and Hemistepta lyrata (stem) did not show toxicity on RAW 264.7 cell proliferation, but treatment with $2.5{\mu}g/ml$ of Boehmeria platanifolia (root) exhibited cell toxicity. Carpinus coreana (branch) and Prunus yedoensis (branch) showed potent scavenging activities on peroxynitrite. Akebia quinata (flower), Carpinus coreana (branch), and Prunus yedoensis (branch) effectively inhibited reactive oxygen species (ROS). Abutilon theophrasti (leaf), Boehmeria platanifolia (root), Carpinus coreana (branch), and Eupatorium japonicum (leaf) exhibited strong inhibitory capacity with regard to nitric oxide (NO) production. The results suggested that Abutilon theophrasti (leaf) has in vitro anti-inflammatory and antioxidant activities, and that is a useful functional material candidate.

• The Korean Journal of Food And Nutrition
• /
• v.16 no.4
• /
• pp.328-333
• /
• 2003

When the extract of the medicinal plants, Kaempferia galanga L., Zanthoxylum bungeanum, Eugenia caryophyllata, Foeniculum vulgare, was added to Naengmyeon broth with the concentration of 0.1% and 0.3% each, its effect during the preservation time of broth was investigated. pH of the extract-added broth was lower than control at the initial, but higher after 72 hours of preservation, which showed that when it added 0.1% and 0.3% of extract to the broth, pH of Kaempferia galanga L. was 4.92 and 5.08 respectively, whereas control was 4.60. Titratable acidity was lowered after 48 hours and also Kaempferia galanga L. showed the lowest acidity with 0.66 for adding 0.1% of its extract and 0.55 for 0.3% of adding, but control was 0.89 at the time of 90 hours of preservation, and then it showed to be lowered in the order of Zanthoxylum bungeanum, Eugenia caryophyllata and Foeniculum vuigare. Turbidity of each broth added the extracts of four of the medicinal plants was 7.5∼7.9 and 7.9∼8.2, respectively for 0.1% and 0.3% of concentration at the initial, but it began to lower and 90 hours later it was 8.8∼9.5 and 8.7∼9.0 respectively, whereas control was 10.8. Total viable cells(TVC) and coliform bacteria(CB) were increased with great at the 72 hours of preservation time, and Kaempferia galanga L. was the most effective, which when control was 4.8${\times}$10 CFU/ml at 72 hours, TVC was 1.7${\times}$10 CFU/ml for the addition of 0.1% of extract and 0.9${\times}$10 CFU/ml for 0.3%. CB was 3.2${\times}$10 CFU/ml for 0.1% and 1.7${\times}$10 CFU/ml for 0.3% respectively and 6.0 ${\times}$ 10 CFU/ml for control at the time of 72 hours, and it was lowered in the order of Zanthoxylum bungeanum, Eugenia caryophyllata and Foeniculum vulgare. Volatile basic nitrogen content detected that control was 2.67mg% at first, and then increased to 3.96mg% at 90 hours of preservation, but the broth added with the extract of Kaempferia galanga L. was 2.58mg% for 0.1% and 2.47mg% for 0.3% at the initial, and at 90 hours it was 3.64mg% and 3.33mg% respectively. The results of adding the extracts of four medicinal plants for the improvement of the preservation time of Naengmyeon broth, were that the most effective medicinal plant was Kaempferia galanga L. and the antimicrobial activity of the medicinal plant extracts for Naengmyeon broth was highly effective after 3 days of preservation time.