• Journal of Nutrition and Health
• /
• 제33권6호
• /
• pp.619-624
• /
• 2000

The purpose of this study was to investigate the effects of vitamin E on microsomal mixed function oxidase system of kidney in streptozotocin(STZ) induced diabetic rats. Sprague-Dawley male rats weighing 140$\pm$10g were randomly assigned to one control and three STZ-diabetic groups which were subdivided into vitamin E free diet(DM-0E group) 40mg vitamin E per kg diet(DM-40E group) and 400mg vitamin E per kg diet(DM-400E group). Vitamin E level of normal group was 40 mg per kg diet. Diabetes was experimentally induced by intravenous administration of 55 mg/kg B.W of STZ in citrate buffer(pH4.3) after 4 weeks feeding of experimental diets. Animals were sacrificed at the 6th day of diabetic state. The contents of cytochrome P450 in kidney were increased by 82, 54, 41% in DM-0E, DM-40E and DM-400E groups respectively when compared with normal group. The contents of cytochrome b5 in kidney were increased by 28% in DM-0E when compared with normal group but those of DM-40E and DM-400E groups were similar to that of normal group. The activities of NADPH-cytochrome P450 reductase in kidney that were increased by 35% in DM-0E group. Levels of TBARS(thiobarbituric acid reactive substance) in kidney were increased by 207, 129% and 72% in DM-0E and DM-400E groups respectively when compared with normal group but those of DM-40E and DM-400E groups were 26,44% lower than that of DM-0E groups. It is know that the activities of MFO system and lipid peroxidation were inhibited in kidney of STZ-induced diabetic rat by administeration of high doses of vitamin E.(Korean J Nutrition 33(6) : 619~624, 2000)

• Parasites, Hosts and Diseases
• /
• 제61권4호
• /
• pp.388-396
• /
• 2023

Entamoeba histolytica is an enteric tissue-invasive protozoan parasite causing amoebic colitis and liver abscesses in humans. Amoebic contact with host cells activates intracellular signaling pathways that lead to host cell death via generation of caspase-3, calpain, Ca²⁺ elevation, and reactive oxygen species (ROS). We previously reported that various NADPH oxidases (NOXs) are responsible for ROS-dependent death of various host cells induced by amoeba. In the present study, we investigated the specific NOX isoform involved in ROS-dependent death of hepatocytes induced by amoebas. Co-incubation of hepatoma HepG2 cells with live amoebic trophozoites resulted in remarkably increased DNA fragmentation compared to cells incubated with medium alone. HepG2 cells that adhered to amoebic trophozoites showed strong dichlorodihydrofluorescein diacetate (DCF-DA) fluorescence, suggesting intracellular ROS accumulation within host cells stimulated by amoebic trophozoites. Pretreatment of HepG2 cells with the general NOX inhibitor DPI or NOX2-specific inhibitor GSK 2795039 reduced Entamoeba-induced ROS generation. Similarly, Entamoeba-induced LDH release from HepG2 cells was effectively inhibited by pretreatment with DPI or GSK 2795039. In NOX2-silenced HepG2 cells, Entamoeba-induced LDH release was also significantly inhibited compared with controls. Taken together, the results support an important role of NOX2-derived ROS in hepatocyte death induced by E. histolytica.

• 대한본초학회지
• /
• 제36권3호
• /
• pp.1-8
• /
• 2021

Objective : Reflux esophagitis (RE), one of gastroesophageal reflux disease (GERD), is a disease that causes inflammation due to reflux of stomach contents such as stomach acid and pepsin due to the unstable gastroesophageal sphincter, and is currently increasing worldwide. The currently used treatment for reflux esophagitis has various side effects. Therefore, in this study the effect of Toosendan Fructus extract on chronic acid reflux esophagitis in rats was evaluated in order to find a new treatment material for reflux treatment. Methods : After inducing reflux esophagitis through surgery, the group was separated and the drug was administered for 2 weeks; Normal rats (Normal, n=8), chronic acid reflux esophagitis rats (Control, n=8), Toosendan Fructus 200 mg/kg body weight/day-treated chronic acid reflux esophagitis rats (TF, n=8). After, we were taken esophageal tissue and esophageal mucosa damage was identified, and analyzed the expression of NADPH oxidase, AP-1/MAPK-related proteins, and tight junction proteins by western blot in esophageal tissue. Results : Toosendan Fructus administration significantly protected the esophageal mucosal damage of reflux esophagitis. Also, Toosendan Fructus significantly reduced the expression of NADPH oxidases (NOX2 and p22^phox) and AP-1/MAPK-related proteins (c-Fos, c-Jun, p-p38, p-ERK, and p-JNK). In addition, it significantly increased the expression of tight junction proteins (Occludin, Claudin-3, and Claudin-4). Conclusions : These results suggest that Toosendan Fructus reduced damage to the esophageal mucosa by protecting the esophageal mucosa by upregulating tight junctions proteins as well as inhibiting the AP-1/MAPK pathway through reducing NADPH oxidases expression.

• Biomolecules & Therapeutics
• /
• 제25권4호
• /
• pp.417-426
• /
• 2017

4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-${\beta}$ (TGF-${\beta}$) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-${\beta}$ signal pathway has not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-${\beta}$-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-${\beta}1$-induced G1/G0 phase arrest and TGF-${\beta}1$-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-${\beta}1$-induced canonical pathway. We observed that ERK phosphorylation by TGF-${\beta}1$ was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-${\beta}1$-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-${\beta}1$-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-${\beta}1$-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-${\beta}1$-induced cell cycle arrest.

• Parasites, Hosts and Diseases
• /
• 제58권3호
• /
• pp.237-247
• /
• 2020

Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H₂O₂-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.

• 한국식품과학회지
• /
• 제46권5호
• /
• pp.622-629
• /
• 2014

생쥐에서의 으름의 열매 추출물의 경구 투여가 알코올로 인한 급성 간독성 상태에서 간보호 효과에 대한 영향을 조사 하였다. 즉, 생쥐 (C57BL/6)에게 1주간 으름 열매 추출물을 투여 하고 희생 전 알코올의 경구 투여를 통해 급성 알코올 간독성을 유발한 후 간 조직 형상, 간 기능 지표(ALT, AST), 간 세포내 GSH 합성 효소(GCLM, GCLC, GSS)의 mRNA 발현량, GSH 농도의 측정, 산화 스트레스 지표인 NOX4의 mRNA 발현량과 염증 반응 지표인 TNF-${\alpha}$의 mRNA 발현량을 조사 하였다. 그 결과, 으름 열매 추출물의 경구 투여는 알코올로 유발된 급성 간독성 상태에서 간 조직내 지방의 축적을 완화 하였고, 혈청 AST, ALT 수치를 개선하였으며, 간조직 내 항산화 물질인 GSH의 농도를 증가시켰다. 더불어 활성산소기를 생성하는 NOX4의 mRNA 발현을 억제 하는 것으로 분석되었으며 염증 반응 지표인 TNF-의 mRNA 발현도 억제 하는 것으로 분석되었다. 따라서 으름의 열매 추출물은 알코올로 유발된 산화 스트레스, 염증 반응에 대한 간보호 효과 가능성을 나타내는 것으로 판단된다.

• Nutritional Sciences
• /
• 제7권4호
• /
• pp.189-195
• /
• 2004

1bis study investigated the antioxidative effect in kidney of senescence-accelerated prone SAMP8 mice with calorie restriction. 4-weeks-old SAMP8 female mice were divided into 4 groups according to the experimental feeding period: for 4, 8, 12 month, and at natural death. Each group was subdivided into 2 groups, with thirteen mice each one, as ad libitum group and as dietary restriction group (60% of ad libitum feeding amount). After feeding for a given period, the mice were sacrificed to get the following results: among the experimental groups, there wereno significant differences in xanthine oxidase (XOD) activity in their kidney tissues. The contents of cytochrome $P_{450}$ decreased in ad libitum group and dietary restriction group by age. The activity of NADPH-cytochrome $P_{450}$ reductase showed a trend similar to cytochrome $P_{450}$. Superoxide radical content increased with age. At the 4th, 8th and 12 months of the experimental period, the activity in the dietary restriction group was less than that of ad libitum group by as much as 17% 14% and 14% respectively. For hydrogen peroxide, the contents were increased in the ad libitum group with age, while no correlation between content and age was observed in the dietary restriction group. In the 8th and 12th months of the experimental period, the were in the dietary restriction group less than that of ad libitum group counterpart as much as 17% and 20o/c, respectively. For the cellular membrane stability of the kidney, no significant correlation with age was observed in either the dietary restriction group or the ad libitum group. However at the 12th month of the experiment, however, the stability in the dietary restriction group was 11 % higher than that in the ad libitum group. In conclusion, with these results obtained from the SAMP8 mouse model, we demonstrate that dietary restriction has the effects of anti-oxidation and anti-senescence in the kidney.

• The Korean Journal of Physiology and Pharmacology
• /
• 제19권6호
• /
• pp.491-497
• /
• 2015

Traumatic brain injury (TBI) is a major cause of mortality and long-term disability, which can decrease quality of life. In spite of numerous studies suggesting that Epigallocatechin-3- gallate (EGCG) has been used as a therapeutic agent for a broad range of disorders, the effect of EGCG on TBI remains unknown. In this study, a weight drop model was established to evaluate the therapeutic potential of EGCG on TBI. Rats were administered with 100 mg/kg EGCG or PBS intraperitoneally. At different times following trauma, rats were sacrificed for analysis. It was found that EGCG (100 mg/kg, i.p.) treatment significantly reduced brain water content and vascular permeability at 12, 24, 48, 72 hour after TBI. Real-time PCR results revealed that EGCG inhibited TBI-induced IL-$1{\beta}$ and TNF-${\alpha}$ mRNA expression. Importantly, CD68 mRNA expression decreasing in the brain suggested that EGCG inhibited microglia activation. Western blotting and immunohistochemistry results showed that administering of EGCG significantly inhibited the levels of aquaporin-4 (AQP4) and glial fibrillary acidic protein (GFAP) expression. TBI-induced oxidative stress was remarkably impaired by EGCG treatment, which elevated the activities of SOD and GSH-PX. Conversely, EGCG significantly reduced the contents of MDA after TBI. In addition, EGCG decreased TBI-induced NADPH oxidase activation through inhibition of $p47^{phox}$ translocation from cytoplasm to plasma membrane. These data demonstrate that EGCG treatment may be an effective therapeutic strategy for TBI and the underlying mechanism involves inhibition of oxidative stress.

• The Korean Journal of Physiology and Pharmacology
• /
• 제26권1호
• /
• pp.25-36
• /
• 2022

To identify the effect and mechanism of carbon monoxide (CO) on delayed rectifier K⁺ currents (I_K) of human cardiac fibroblasts (HCFs), we used the wholecell mode patch-clamp technique. Application of CO delivered by carbon monoxidereleasing molecule-3 (CORM3) increased the amplitude of outward K⁺ currents, and diphenyl phosphine oxide-1 (a specific I_K blocker) inhibited the currents. CORM3-induced augmentation was blocked by pretreatment with nitric oxide synthase blockers (L-NG-monomethyl arginine citrate and L-NG-nitro arginine methyl ester). Pretreatment with KT5823 (a protein kinas G blocker), 1H-[1,-2,-4] oxadiazolo-[4,-3-a] quinoxalin-1-on (ODQ, a soluble guanylate cyclase blocker), KT5720 (a protein kinase A blocker), and SQ22536 (an adenylate cyclase blocker) blocked the CORM3 stimulating effect on I_K. In addition, pretreatment with SB239063 (a p38 mitogen-activated protein kinase [MAPK] blocker) and PD98059 (a p44/42 MAPK blocker) also blocked the CORM3's effect on the currents. When testing the involvement of S-nitrosylation, pretreatment of N-ethylmaleimide (a thiol-alkylating reagent) blocked CO-induced I_K activation and DL-dithiothreitol (a reducing agent) reversed this effect. Pretreatment with 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)-21H,23H porphyrin manganese (III) pentachloride and manganese (III) tetrakis (4-benzoic acid) porphyrin chloride (superoxide dismutase mimetics), diphenyleneiodonium chloride (an NADPH oxidase blocker), or allopurinol (a xanthine oxidase blocker) also inhibited CO-induced I_K activation. These results suggest that CO enhances I_K in HCFs through the nitric oxide, phosphorylation by protein kinase G, protein kinase A, and MAPK, S-nitrosylation and reduction/oxidation (redox) signaling pathways.

• Journal of Applied Biological Chemistry
• /
• 제59권1호
• /
• pp.25-29
• /
• 2016

B형 간염 바이러스는 간경변증과 간세포암의 원인이 되는 간섬유화를 유발한다. 하지만 현재까지 그와 관련한 자세한 메커니즘은 밝혀지지 않았기에 본 연구에서 이를 알아보고자 하였다. 실험 결과, B형 간염 바이러스에서 발현되는 HBx 단백질에 의해 vimentin, fibronectin, slug, snail, NOX4가 증가되는 것을 확인하였다. NOX4에 의한 활성산소가 snail, slug 발현을 유도하고 섬유화 과정을 촉진할 수 있기 때문에 NOX4의 발현을 유도하는 HBx가 간섬유화를 조절, 유도하는 것을 확인하였다.