• Toxicological Research
• /
• 제12권2호
• /
• pp.265-270
• /
• 1996

Effects of a single administration of dichloromethane (DCM) on the hepatic drug metabollzing activity were determined using adult female rats. Rats were treated with DCM (3 mmol/kg, ip) and the disappearance of antipyrine (100 mg/kg, iv) or ethanol (2 g/kg, ip) from blood was measured. The blood concentration and half-life of antipyrine was not influenced by DCM administration. And DCM did not alter the blood concentration of ethanol measured for 240 min after the treatment. The effect of DCM treatment on in vitro cytochrome P-450-dependent enzyme activities was examined as well. No significant difference in either aniline hydroxylase or aminopyrine N-demethylase was observed in hepatic microsomal fractiorts of rats treated with DCM 24 hr prior to sacrifice. The present study indicates that acutely given DCM does not alter the metabolism of xenobiotics in vivo. The failure of DCM to alter the in vitro hepatic microsomal drug metabolizing activity was also noted.

• Molecules and Cells
• /
• 제37권10호
• /
• pp.734-741
• /
• 2014

Histone modifications on major transcription factor target genes are one of the major regulatory mechanisms controlling adipogenesis. Plant homeodomain finger 2 (PHF2) is a Jumonji domain-containing protein and is known to demethylate the histone H3K9, a repressive gene marker. To better understand the function of PHF2 in adipocyte differentiation, we constructed stable PHF2 knock-down cells by using the mouse pre-adipocyte cell line 3T3-L1. When induced with adipogenic media, PHF2 knock-down cells showed reduced lipid accumulation compared to control cells. Differential expression using a cDNA microarray revealed significant reduction of metabolic pathway genes in the PHF2 knock-down cell line after differentiation. The reduced expression of major transcription factors and adipokines was confirmed with reverse transcription- quantitative polymerase chain reaction and Western blotting. We further performed co-immunoprecipitation analysis of PHF2 with four major adipogenic transcription factors, and we found that CCATT/enhancer binding protein (C/EBP)${\alpha}$ and C/EBP${\delta}$ physically interact with PHF2. In addition, PHF2 binding to target gene promoters was confirmed with a chromatin immunoprecipitation experiment. Finally, histone H3K9 methylation markers on the PHF2-binding sequences were increased in PHF2 knock-down cells after differentiation. Together, these results demonstrate that PHF2 histone demethylase controls adipogenic gene expression during differentiation.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권3호
• /
• pp.319-327
• /
• 2009

Follicular fluid meiosis-activating sterol (FF-MAS) has been suggested as a positive factor which could improve the oocyte quality and subsequent embryo development after in vitro fertilization. However, FF-MAS is a highly lipophilic substance and is hard to detect in studying the relationship between MAS and quality of oocyte maturation. The present study focused on the expression of lanosterol 14${\alpha}$-demethylase (LDM), a key enzyme that converts lanosterol to FF-MAS, on mouse oocyte maturation and its potency on development. LDM expression was strong in gonadotropin-primed germinal vesicle stage oocytes, weak after germinal vesicle breakdown (GVBD), and then strong in MII stage oocytes. The LDM-specific inhibitor azalanstat significantly inhibited oocyte fertilization (from 79.4% to 68.3%, p<0.05). Also, azalanstat (5 to 50 ${\mu}M$) decreased the percentage of blastocyst development dosedependently (from 78.7% to 23.4%, p<0.05). The specific inhibition of sterol ${\Delta}14$-reductase and ${\Delta}7$-reductase by AY9944 accumulates FF-MAS and could increase blastocyst development rates. Additionally, in the AY9944 group, the rate of inner cell mass (ICM)/ total cells was similar to that of in vivo development, but the rate was significantly decreased in azalanstat treatment. In conclusion, LDM, the key enzyme of FF-MAS production, may play an important role in fertilization and early development of the mouse embryo, especially in vitro.

• 생약학회지
• /
• 제31권2호
• /
• pp.228-234
• /
• 2000

Effects of Houttuynia cordata on the level of lipid peroxide and the enzyme activities of the liver were investigated in bromobenzene-induced rats. Lipid peroxide content in liver was increased by bromobenzene. It was decreased when the methanol extract from the aerial parts of H. cordata was treated to the rat. The methanol extract reduced the activities of aminopyrine N-demethylase and aniline hydroxylase that increased by bromobenzene, however did not affect glutathione S-transferase activity. The methanol extract recovered the activity of epoxide hydrolase activity that decreased significantly by bromobenzene. We suggest that under our experimental conditions the extract might play an important play in the prevention of hepatotoxicity by reduction of aminopyrine N-demethylase and aniline hydroxylase activities as well as enhancement of epoxide hydrolase activity. Six phenolic compounds have been isolated from H. cordata and identified by means of spectral analysis as protocatechuic acid, quercetin, apigenin, afzelin, hyperoside and quercitrin.

• 생명과학회지
• /
• 제13권2호
• /
• pp.230-235
• /
• 2003

Bromobenzene으로 간독성을 유발한 흰쥐에 생열귀나무 뿌리를 투여하여 bromobenzene 대사계에 미치는 효소활성을 관찰하였다. Bromobenzene은 bromobenzene 2,3-oxide와 bromobenzene-3, 4-oxide로 전환되며, 3,4-oxide는 독성물질로서 epoxide hydrolase에 의해 무독성 bromobenzene-3,4-dihyrodiol로 대사 또는 glutathione S-transferase에 의하여 배설되기도 한다. 중국 민간에서 강장제로 사용하는 생열귀나무는 한방에서 소화불량, 위통 등의 치료에 사용되는 약용식물이다. 생열귀나무의 뿌리 추출물은 흰쥐의 간 epoxide 생성계에 관여하는 aminopyrine N-demethylase, aniline hydroxylase 활성과 epoxide를 대사시키는 glutathione S-transferase 활성에는 변화를 주지 않았다. 그러나 생열귀추출물 500 mg/kg 경구투여군은 eporide를 무독화시키는 epoxide hydrolase 활성에서 bromobenzene 투여로 효소활성이 저하된 대조군보다 33% 활성을 회복시켰다. 따라서 생열귀나무 뿌리는 간독성물질인 bromobenzene 대사에 관여하는 epoxide hydrolase 활성 증가로 인해 간보호작용이 일어나는 것으로 판단된다.

• Biomolecules & Therapeutics
• /
• 제2권2호
• /
• pp.141-148
• /
• 1994

This study was done to determine whether specific alterations exist in hepatic microsomal function after varying periods of ischemia (IS) and reperfusion (RP) during microsomal lipid peroxidation occurs. Rats were pretreated with $\alpha$-tocopherol to inhibit lipid peroxidation or with vehicle (soybean oil). Control animals were time-matched sham-ischemic animals. Four groups of animals were studied: Group 1 (sham), group 2 (30 mins IS), group 3 (60 mins IS) and group 4 (90 mins IS). After 1, 5 or 24 hr of reperfusion, liver microsomes were isolated and cytochrome P-450s were studied. In all vehicle-treated ischemic rats, serum ALT levels peaked at 5 hr and were significantly reduced by $\alpha$-tocopherol pretreatment. Similarly, microsomal lipid peroxidation was elevated in all vehicle-treated ischemic animal groups, but this elevation was prevented by $\alpha$-tocopherol pretreatment. Cytochrome P-450 content was significantly decreased in both group 3 and group 4. In all vehicle-treated ischemic animal groups, aminopyrine N-demethylase activity was significantly decreased for the entire reperfusion period. $\alpha$-Tocopherol inhibited reductions of cytochrome P-450 content and aminopyrine N-demethylase activity at both 1 hr and 5hr of reperfusion but did not affect the reduced levels of cytochrome P-450 content and aminopyrine N-demethylase activity at 24 hr of reperfusion. Aniline p-hydroxylase activity was significantly decreased in group 4, whereas it was increased in group 3. These decreases and increases were prevented by $\alpha$-tocopherol pretreatment. Our finding suggests that abnormalities in microsomal drug metabolizing function occur during hepatic ischemia and reperfusion in vivo and this is attributed to microsomal lipid peroxidation.

• 한국식품과학회지
• /
• 제32권5호
• /
• pp.1179-1185
• /
• 2000

멸치액젓의 용매분획을 $50^{\circ}C$에서 10일동안 항온실험한 경우 각 용매분획의 건조중량 10 ${\mu}g$ 또는 20 ${\mu}g$이 5 mg의 linoleic acid의 자동산화를 저해하는 것으로 나타났으며, 용매분획 중 부탄올분획 및 수용액분획이 염분을 함유하고 있었고 염분의 함량은 각각 12.2% 및 21.1%이었다. 흰쥐에게 간장독성을 유발시킨다고 알려진 bromobenzene을 주사하고 간조직을 분리하여 in vitro에서 멸치액젓이 간균질액의 지질과산화물 생성에 미치는 효과를 관찰한 결과, 모든 용매분획들이 3 mg/mL 또는 1 mg/mL 농도에서 지질과산화물 생성을 강하게 감소시켰으며 수용액분획의 경우 0.3 mg/mL 농도에서도 활성을 가지는 것으로 나타났다. 간조직의 지질과산화반응에 관여하는 것으로 알려진 효소들 중 aniline hydroxylase, aminopyrine N-demethylase, xanthine oxidase 및 aldehyde oxidase 활성에 대한 멸치액젓의 효과를 관찰한 결과, 간세포 마이크로솜 분획에 존재하는 aniline hydroxylase 및 aminopyrine N-demethylase의 활성을 모든 용매분획이 저해하였다. 즉, 3 mg/mL 농도에서는 거의 정상쥐의 효소활성 수준까지 회복시켰고, 0.3 mg/mL의 농도에서도 유의적인 효과가 나타났으나 세포질 효소인 xanthine oxidase 및 aldehyde oxidase의 활성에 대하여는 저해효과가 나타나지 않았다. 이와 같은 결과로부터, bromobenzene-유도 간지질의 과산화물 생성과정에 있어서 멸치액젓의 항산화물질들은 free radical을 포획하여 지질과산화물 생성을 억제하는 것이 아니라 epoxide생성단계를 저해하여 과산화지질 생성을 억제하는 것으로 사료된다.

• 환경위생공학
• /
• 제10권3호
• /
• pp.16-28
• /
• 1995

Influences of capsaicin on the activities of cytochrome P45O of liver cell were studied in rats. Rats were provided food and water ad libitum and capsaicin and methylcellulose were gavaged for 6 days. Body weight gain and liver weight/body weight ratio, microsomal protein content and serum HDL- cholesterol content, the activity of cytochrome P450 and erythromycin demethylase, the activities of ethoxyresorufin and pentoxyresorufin O- dealkylase were determined. Capsaicin increased body weight gain but showed no significant changes on liver weight as compared with control group. Capsaicin increased the microsomal protein significantly but decreased the serum HDL- cholesterol. Capsaicin decreased the microsomal cytochrome P4SO significantly and did not show any influences on erythromycin demethylase ( cytochrome P45O III A ). Capsaicin increased the activity of pentoxyresorufin O- dealkylase ( cytochrome P45O II B) and decreased the activity of ethoxyresorufin O-dealkylase ( cytochrome P45O I A). It might be concluded that capsaicin reduced the microsomal cytochrome P45O and induced the CYP III and inhibited the CYP I A. It also might be concluded that capsaicin had no influence on CYP III A and decreased serum HDL- cholesterol. In these results capsaicin can not be used as an anti- atherosclerotic agent by increasing the CYP III A and HDL- cholesterol but it is considered that the more precise study on these theme is necessary.

• BMB Reports
• /
• 제49권7호
• /
• pp.388-393
• /
• 2016

Although brown adipose tissue is important with regard to energy balance, the molecular mechanism of brown adipocyte differentiation has not been extensively studied. Specifically, regulation factors at the level of protein modification are largely unknown. In this study, we examine the changes in the expression level of enzymes which are involved in protein lysine methylation during brown adipocyte differentiation. Several enzymes, in this case SUV420H2, PRDM9, MLL3 and JHDM1D, were found to be up-regulated. On the other hand, Set7/9 was significantly down-regulated. In the case of SUV420H2, the expression level increased sharply during brown adipocyte differentiation, whereas the expression of SUV420H2 was marginally enhanced during the white adipocyte differentiation. The knock-down of SUV420H2 caused the suppression of brown adipocyte differentiation, as compared to a scrambled control. These results suggest that SUV420H2, a methyltransferase, is involved in brown adipocyte differentiation, and that the methylation of protein lysine is important in brown adipocyte differentiation.

• BMB Reports
• /
• 제50권1호
• /
• pp.49-54
• /
• 2017

Previously, we reported that vitamin C facilitates the CpG demethylation of Foxp3 enhancer in $CD4^+Foxp3^+$ regulatory T cells (Tregs) by enhancing the activity of a DNA demethylase ten-eleven-translocation (Tet). However, it is not clear whether vitamin C affects other helper T cell lineages like T helper type 17 (Th17) cells which are related with Tregs. Here, we show that the expression of interleukin-17A (IL17) increases with the treatment of vitamin C but not with other antioxidants. Interestingly, the upregulation of IL17 was not accompanied by DNA demethylation in Il17 promoter and was independent of Tet enzymes. Rather, vitamin C reduced the trimethylation of histone H3 lysine 9 (H3K9me3) in the regulatory elements of the Il17 locus, and the effects of vitamin C were abrogated by knockdown of jumonji-C domain-containing protein 2 (jmjd2). These results suggest that vitamin C can affect the expression of IL17 by modulating the histone demethylase activity.