Yoonhwa Jeong

Activation of PERK Signaling Attenuates Aβ-Mediated ER Stress

Alzheimers disease (AD) is characterized by the deposition of aggregated beta-amyloid (Aβ), which triggers a cellular stress response called the unfolded protein response (UPR). The UPR signaling pathway is a cellular defense system for dealing with the accumulation of misfolded proteins but switches to apoptosis when endoplasmic reticulum (ER) stress is prolonged. ER stress is involved in neurodegenerative diseases including AD, but the molecular mechanisms of ER stress-mediated Aβ neurotoxicity still remain unknown. Here, we show that treatment of Aβ triggers the UPR in the SK-N-SH human neuroblastoma cells. Aβ mediated UPR pathway accompanies the activation of protective pathways such as Grp78/Bip and PERK-eIF2α pathway, as well as the apoptotic pathways of the UPR such as CHOP and caspase-4. Knockdown of PERK enhances Aβ neurotoxicity through reducing the activation of eIF2α and Grp8/Bip in neurons. Salubrinal, an activator of the eIF2α pathway, significantly increased the Grp78/Bip ER chaperone resulted in attenuating caspase-4 dependent apoptosis in Aβ treated neurons. These results indicate that PERK-eIF2α pathway is a potential target for therapeutic applications in neurodegenerative diseases including AD.

Anti-inflammatory effect of fucoidan extracted from Ecklonia cava in zebrafish model.

Fucoidan extracted from Ecklonia cava had strong anti-inflammatory activities. However, the direct effects of fucoidan of E. cava on anti-inflammatory activities in vivo model remained to be determined. Therefore, the present study was designed to assess in vivo anti-inflammatory effect of fucoidan extracted from E. cava (ECF) using tail-cutting-induced and lipopolysaccharide (LPS)-stimulated zebrafish model. Treating zebrafish model with tail-cutting and LPS-treatment significantly increased the ROS and NO level. However, ECF inhibited this tail-cutting-induced and LPS-stimulated ROS and NO generation. These results show that ECF alleviated inflammation by inhibiting the ROS and NO generation induced by tail-cutting and LPS-treatment. In addition, ECF has a protective effect against the toxicity induced by LPS exposure in zebrafish embryos. This outcome could explain the potential anti-inflammatory activity of ECF, which might have a beneficial effect during the treatment of inflammatory diseases.

Physicochemical and Microbial Properties of the Korean Traditional Rice Wine, Makgeolli, Supplemented with Banana during Fermentation

The objective of the present study was to evaluate the physicochemical and microbial properties of the Korean traditional rice wine Makgeolli, supplemented with banana during 6 day fermentation. The alcohol contents of the control and banana Makgeolli were 17.0 and 16.5%, respectively. The pH values decreased while total acidity, total soluble solids, and color values increased throughout the fermentation process. An increase in microorganism counts throughout the 6-day fermentation period was noted in all samples. The major free sugar and organic acid detected in all samples were glucose and succinic acid, respectively. There were 39 volatile compounds detected in the control and banana Makgeolli. The major ester detected was ethyl acetate (20.037 and 22.604% for the control and banana Makgeolli, respectively). The major alcohol compounds detected were 3-methylbutanol (20.933%) and 3-methyl-1-butanol (34.325%) in the control. 2-mtehyl-1-propanol (22.289%) and 3-methyl-1-butanol (39.851%) were the highest alcohol compounds detected in the banana Makgeolli.

Anticancer activity of subfractions containing pure compounds of Chaga mushroom (Inonotus obliquus) extract in human cancer cells and in Balbc/c mice bearing Sarcoma-180 cells

The Chaga mushroom (Inonotus obliquus) has been used in folk medicine to treat cancers. However, limited information exists on the underlying anticancer effects of the major component of I. obliquus in vivo. We hypothesize that the pure compounds (3β-hydroxy-lanosta-8,24-dien-21-al, inotodiol and lanosterol, respectively) separated from I. obliquus would inhibit tumor growth in Balbc/c mice bearing Sarcoma-180 cells (S-180) in vivo and growth of human carcinoma cells in vitro. To test this hypothesis, the growth inhibition of each subfraction isolated from I. obliquus on human carcinoma cell lines (lung carcinoma A-549 cells, stomach adenocarcinoma AGS cells, breast adenocarcinoma MCF-7 cells, and cervical adenocarcinoma HeLa cells) was tested in vitro. Then, after S-180 implantation, the mice were fed a normal chow supplemented with 0, 0.1 or 0.2 mg of subfraction 1, 2 or 3 per mouse per day. All of the subfractions isolated from I. obliquus showed significant cytotoxic activity against the selected cancer cell lines in vitro. Subfraction 1 was more active than subfraction 2 and subfraction 3 against the A549, AGS and MCF-7 cancer cell lines in vitro. In in vivo results, subfraction 1 isolated from I. obliquus at concentrations of 0.1 and 0.2 mg/mouse per day significantly decreased tumor volume by 23.96% and 33.71%, respectively, as compared with the control. Subfractions 2 and 3 also significantly inhibited tumor growth in mice bearing S-180 as compared with the control mouse tumor. Subfraction 1 isolated from I. obliquus showed greater inhibition of tumor growth than subfractions 2 and 3, which agrees well with the in vitro results. The results suggest that I. obliquus and its compounds in these subfractions isolated from I. obliquus could be used as natural anticancer ingredients in the food and/or pharmaceutical industry.

Metabolomic analysis of the effect of shade treatment on the nutritional and sensory qualities of green tea.

We analyzed metabolites from a 50% aqueous methanol extract of green teas treated with different shade periods (0, 15, 18, and 20 days) to investigate the effect of low light on their nutritional and sensory qualities. The shaded groups could be clearly distinguished from the control (0 day), and the 20 day group was separated from the 15 and 18 day groups. The shade treatment increased quercetin-galactosylrutinoside, kaempferol-glucosylrutinoside, epicatechin gallate, epigallocatechin gallate, tryptophan, phenylalanine, theanine, glutamine, glutamate, and caffeine levels but decreased quercetin-glucosylrutinoside, kaempferol-glucoside, gallocatechin, and epigallocatechin levels. Further studies on the nutritional benefits of these metabolites are needed. However, this result, along with the sensory evaluation and color measurement data, suggests that shade treatment improves the nutritional and sensory quality of green tea. Thus, we proposed a metabolomic pathway related to the effect of low light, which could elucidate the relationship between low light and tea quality.

New Functional Probiotic Lactobacillus sakei Probio 65 Alleviates Atopic Symptoms in the Mouse

The purpose of this study was to investigate the improvement of allergic dermatitis in chemical allergen-induced mice by Lactobacillus sakei probio 65. L. sakei probio-65 was isolated from kimchi, a traditional Korean fermented food. This strain was resistant to gastric acidity, bile, and several antibiotics and possessed antimicrobial activity against several pathogenic microorganisms. To investigate whether the probiotic activity of L. sakei probio 65 was effective for treating allergic dermatitis, the organism was supplied to mice triggered by allergen (1-chloro-2,4-dinitrobenzene). Mice that received L. sakei probio 65 showed a more rapid recovery compared to control mice, as assessed by visual evaluation of the severity of allergic dermatitis and levels of immunoglobulin (Ig) E and interleukin (IL)-4. L. sakei probio 65 exhibited good probiotic properties in vitro and in mice and was effective in reducing allergen-induced skin inflammation through the regulation of both elevated IgE and IL-4 in sensitized mice.

Utilization of whole sweet sorghum containing juice, leaves, and bagasse for bio-ethanol production.

Sweet sorghum is one of the most attractive feedstocks for producing liquid fuels in the world since it is well adapted to the various land conditions and efficiently converts CO2 into sugars. Sweet sorghum was evaluated as a raw substrate for production of ethanol from the whole plant. It consists of 37% juice, 8% seed head, 36% bagasse, and 19% leaf matter which can produce ethanol via fermentation of Saccharomyces cerevisiae. Especially, starch in seeds was hydrolyzed to simple sugars by amylase. Bagasse and leaf matter were treated with calcium hydroxide at 121°C for 1 h at 15 psi before hydrolysis by cellulase. In this study, 1 ton of whole sweet sorghum contains 283 kg solid matter and 229.8 kg carbohydrates and produces 59 kg ethanol.

The ingredients in Saengshik, a formulated health food, inhibited the activity of α-amylase and α-glucosidase as anti-diabetic function

BACKGROUND/OBJECTIVES We investigated total 26 ingredients of Saengshik which will be commercially produced as an anti-diabetic dietary supplement. SUBJECTS/METHODS Thirteen vegetables, nine cereals, three legumes and one seed were extracted with aqueous ethanol for 2 h at 60℃, and evaluated for their inhibitory effects against α-amylase and α-glucosidase and for total phenolic and flavonoid contents. RESULTS All ingredients inhibited α-amylase activity except cabbage. Strong inhibitory activity of α-amylase was observed in leek, black rice, angelica and barley compared with acarbose as a positive control. Stronger inhibition of α-glucosidase activity was found in small water dropwort, radish leaves, sorghum and cabbage than acarbose. All Saengshik ingredients suppressed α-glucosidase activity in the range of 0.3-60.5%. Most ingredients contained total phenols which were in the range of 1.2-229.4 mg gallic acid equivalent/g dried extract. But, total phenolic contents were not observed in carrot, pumpkin and radish. All ingredients contained flavonoid in the range of 11.6-380.7 mg catechin equivalent/g dried extract. CONCLUSIONS Our results demonstrate that Saengshik containing these ingredients would be an effective dietary supplement for diabetes.

Glycyrrhiza glabra L. Extract Inhibits LPS-Induced Inflammation in RAW Macrophages.

Glycyrrhiza glabra has been used in medicine for thousands of years. Our previous study revealed that the methanolic extract of Glycyrrhiza glabra L. (EGGR) exhibits significant nitric oxide (NO) inhibitory effect on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages among 100 other extracts. Accordingly, the aim of the present study was to investigate the potential anti-inflammatory effect of EGGR. The anti-inflammatory effect of EGGR on LPS-stimulated RAW 264.7 macrophages was measured by MTT assay, NO content analysis, reactive oxygen species (ROS) level analysis, RT-PCR, Western blot analysis, and ELISA assay. Low doses of EGGR were non-toxic to macrophages and imparted protective effect against LPS induced cell death. Incubation of LPS-treated macrophages with 100 μg/mL EGGR led to an increase in cell viability from 66.6 to 99%. Moreover, EGGR led to down regulation of NO (NO2+NO3) and ROS productions in a dose-dependent manner. In particular, 100 μg/mL EGGR led to a reduction in NO2+NO3 level from 336.2 to 24.1 pM/mL, and ROS level from 483.5 to 128.4%. Consistent with the result related to NO production, EGGR suppressed the ability of LPS to induce mRNA and protein expressions of nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) cytokines, tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and IL-6 productions which were analyzed by an ELISA assay. These results provide a comprehensive approach into the anti-inflammatory effect of EGGR on LPS-stimulated macrophages; however, efforts are underway on gaining detailed insight into anti-inflammatory signaling pathways.

Polyphenol oxidase inhibitor from blue mussel (Mytilus edulis) extract.

UNLABELLED Enzymatic browning remains a problem for the fruit and vegetable industry, especially new emerging markets like pre-cuts. A crude inhibitor from blue mussel (Mytilus edulis) showed broad inhibition for apple (58%), mushroom (32%), and potato (44%) polyphenol oxidase (PPO) and was further characterized. Inhibition increased as the concentration of inhibitor increased in the reaction mixture eventually leveling off at a maximum inhibition of 92% for apple PPO. The inhibitor was capable of bleaching the brown color formed in the reaction mixture with apple PPO. Identification of the inhibitor by mass spectrometry and high-performance liquid chromatography revealed it to be hypotaurine (C2 H7 NO2 S). Hypotaurine and other sulfinic acid analogs (methane and benzene sulfinic acids) showed very good inhibition for apple PPO at various concentrations with the highest inhibition occurring at 500 μM for hypotaurine (89%), methane sulfinic acid (100%), and benzene sulfinic acid (100%). PRACTICAL APPLICATION An inhibitor found in the expressed liquid from blue mussel shows very good inhibition on enzymatic browning. Since this enzyme is responsible for losses to the fruit and vegetable industry, natural inhibitors that prevent browning would be valuable. Finding alternative chemistries that inhibit browning and understanding their mode of action would be beneficial to the fruit and vegetable industries and their segments such as pre-cuts, juices, and so on. Inhibitors from products ingested by consumers are more acceptable as natural ingredients.