Gyeongnam Provincial Namhae College

Free radical is a marker in various inflammatory diseases. The antioxidant effect protects us from this damage, which also plays an essential role in preventing inflammation. Inflammation protects the body from biological stimuli, and pro-inflammatory mediators are negatively affected in the immune system. Inflammation caused by LPS is an endotoxin found in the outer membrane of Gram-negative bacteria, which induces immune cells to produce inflammatory cytokines such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase. Based on this, the antioxidant and anti-inflammatory effects of plant extracts were investigated. First, the main phenolic compounds for the five peaks obtained from Stachys affinis extract (SAE) were identified. The antioxidant effect of each phenolic compound was confirmed through HPLC analysis before and after the competitive binding reaction between DPPH and the extract. Afterward, the anti-inflammatory effect of each phenolic compound was confirmed through competitive binding between COX2 and the extract in HPLC analysis. Lastly, the anti-inflammatory effect of SAE was confirmed through in vitro experiments and also confirmed in terms of structural binding through molecular docking. This study confirmed that phenolic compounds in SAE extract have potential antioxidant and anti-inflammatory effects, and may provide information for primary screening of medicinal plants.

CYP102A1 from Bacillus megaterium is an important enzyme in biotechnology, because engineered CYP102A1 enzymes can react with diverse substrates and produce human cytochrome P450-like metabolites. Therefore, CYP102A1 can be applied to drug metabolite production. Terpinen-4-ol is a cyclic monoterpene and the primary component of essential tea tree oil. Terpinen-4-ol was known for therapeutic effects, including antibacterial, antifungal, antiviral, and anti-inflammatory. Because terpenes are natural compounds, examining novel terpenes and investigating the therapeutic effects of terpenes represent responses to social demands for eco-friendly compounds. In this study, we investigated the catalytic activity of engineered CYP102A1 on terpinen-4-ol. Among CYP102A1 mutants tested here, the R47L/F81I/F87V/E143G/L188Q/N213S/E267V mutant showed the highest activity to terpinen-4-ol. Two major metabolites of terpinen-4-ol were generated by engineered CYP102A1. Characterization of major metabolites was confirmed by liquid chromatography-mass spectrometry (LC-MS), gas chromatography-MS, and nuclear magnetic resonance spectroscopy (NMR). Based on the LC-MS results, the difference in mass-to-charge ratio of an ion (m/z) between terpinen-4-ol and its major metabolites was 16. One major metabolite was defined as 1,4-dihydroxy-p-menth-2-ene by NMR. Given these results, we speculate that another major metabolite is also a mono-hydroxylated product. Taken together, we suggest that CYP102A1 can be applied to make novel terpene derivatives.

Kyeong Ho Chung, Eun Young Nam, Jung Hyun Kwon, Youn Young Hur, Soon Il Kwon, Yoon Kyeong Kim, Kyeong Bok Ma, Su Hyun Yun, Mock Hee Lee, Young Sik Park, Seok Ho Lee, EunJu Kim, Moon Young Park, Won Heum Park, Hyung Il Lee, Hye Young Suh, Eun Gyeong Kim, and Jong Hoon Kang. Korean J. Breed. Sci. 2020;52:144-60. https://doi.org/10.9787/KJBS.2020.52.S.144

The cabin crew plays a very important role in ensuring safe flight operations and quality services. In particular, it is their responsibility to successfully implement emergency evacuations of passengers in the event of an emergency. As a result, cabin crews undergo intense emergency training. In order to support firefighter training of cabin crews, this study investigated the method of firefighter training that can be easily carried out in small spaces in the office or indoor spaces without water supplies and drainages using light as an aircraft fire suppression training device. The fire suppression training device using the light presented in this study consists of a screen part, fire extinguisher part, and control part. The flame images classified as per the fire causes are displayed on the screen by using visible light, and it is set to correspond to each fire cause. Fire extinguishing drills can be conducted using fire extinguishers that emit infrared light in a specific wavelength band.

Volume-regulated anion channels (VRACs) are involved in cellular functions such as regulation of cell volume, proliferation, migration, and cell death. Although leucine-rich repeat–containing 8A (LRRC8A) has been characterized as a molecular component of VRACs, here we show that Drosophila melanogaster tweety homologue 1 and 2 (TTYH1 and TTYH2) are critical for VRAC currents in cancer cells. LRRC8A-independent VRAC currents were present in the gastric cancer cell line SNU-601, but almost completely absent in its cisplatin-resistant derivative SNU-601-R10 (R10). The VRAC current in R10 was partially restored by treatment with trichostatin A (TSA), a histone deacetylase inhibitor. Based on microarray expression profiling of these cells, we selected two chloride channels, TTYH1 and TTYH2, as VRAC candidates. VRAC currents were completely absent from TTYH1- and TTYH2-deficient SNU-601 cells, and were clearly restored by expression of TTYH1 or TTYH2. In addition, we examined the expression of TTYH1 or TTYH2 in several cancer cell lines and found that VRAC currents of these cells were abolished by gene silencing of TTYH1 or TTYH2. Taken together, our data clearly show that TTYH1 and TTYH2 can act as LRRC8A-independent VRACs, suggesting novel therapeutic approaches for VRACs in cancer cells.

We synthesized gallic acid (GA)‐conjugated chitosan (abbreviated as chitogallate) to study its antitumor activity against CT26 mouse colorectal carcinoma cells. GA was conjugated with chitosan by aid of water‐soluble carbodiimide. Chitogallate nanoparticles were prepared by dialysis method, and these nanoparticles have spherical shapes with sizes ranged about 70–250 nm. Chitogallate nanoparticles have superior antioxidants activities as well as GA itself. At cytotoxicity study, GA showed dose‐dependent cytotoxicities against CCD986sk cells and CT26 cells while chitogallate nanoparticles were not significantly affected to the viability of cells. In Matrigel invasion assay, chitogallate nanoparticles have superior anti‐invasive capacity against cancer cells as well as GA itself, i.e., invasiveness of CT26 cells was decreased according to GA contents in chitogallate nanoparticles. Furthermore, gelatin zymography also showed that chitogallate nanoparticles having higher substitution degree of GA decreased matrix metalloproteinase‐2 activity. Chitogallate nanoparticles efficiently inhibited pulmonary metastasis of CT26 cells in animal pulmonary metastasis model. We prepared chitogallate nanoparticles for application as an anti‐invasive agent. Chitogallate nanoparticles were less toxic than GA itself and have superior anti‐invasive/antimetastatic activity. We suggest that chitogallate nanoparticles are promising candidate for inhibition of tumor invasion/metastasis.

ABSTRACT‘Fuyu’ is the most cultivated persimmon variety worldwide, but it is susceptible to storage disorders. Thus, it is necessary to improve its storage quality using postharvest technologies. Here, ‘Fuyu’ persimmon fruit were preconditioned after harvest by exposing them to high temperature (30°C) and low, medium, or high relative humidity for 6 or 24 h. Fruit were stored at room temperature for 15 days or cold room (0°C) for 40 days. Subsequently, the effect of the preconditioning on the firmness, soluble solids content, and colour (Hunter a and b values) of the fruit was evaluated. Persimmon preconditioned at 30°C and low (<30%) humidity for 24 h exhibited lower incidence of storage disorders, as well as greater firmness and total soluble solids and less reddening than did fruit in other treatment groups. The results suggest that the proposed preconditioning can delay quality deterioration in ‘Fuyu’ persimmon during storage.