• 대한의생명과학회지
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• 제9권4호
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• pp.189-193
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• 2003

This study was undertaken to investigate the effect of baicalein, a major flavone component of Scutellaria balicalensis Georgi, on oxidant-induced cell injury in renal epithelial cells. Opossum kidney cells, an established proximal tubular epithelial cells, were used as a cell model of renal epithelial cells and t-butylhydroperoxide (tBHP) as an oxidant drug model. Cell viability was measured by MTT assay and lipid peroxidation was estimated by measuring the content of malondialdehyde, a product of lipid peroxidation. Exposure of cells to tBHP caused cell death and its effect was dose-dependent over concentration range of 0.1~1.0 mM. When cells were exposed to tBHP in the presence of various concentrations (0.1~10 $\mu$M) of baicalein, tBHP-induced cell death was prevented with a manner dependent of baicalein concentration. tBHP induced A TP depletion, which was significantly prevented by baicalein. Similarly, tBHP-induced DNA damage was prevented by baicalein. tBHP produced a marked increase in lipid peroxidation and its effect was completely inhibited by baicalein. These results indue ate that tBHP induces cell injury through a lipid peroxidation-dependent mechanism in renal epithelial cells, and baicalein prevented oxidant-induced cell injury via antioxidant action inhibiting lipid peroxidation. In addition, these results suggest that baicalein may be a candidate for development of drugs which are effective in preventing and treating renal diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제1권4호
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• pp.367-376
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• 1997

The effect of an organic peroxide, t-butylhydroperoxide (t-BHP), on glutamate uptake was studied in synaptosomes prepared from cerebral cortex. t-BHP inhibited the $Na^+-dependent$ glutamate uptake with no change in the $Na^+-independent$ uptake. This effect of t-BHP was not altered by addition of $Ca^{2+}$ channel blockers (verapamil, diltiazem and nifedipine) or $PLA_2$ inhibitors (dibucaine, butacaine and quinacrine). However, the effect was prevented by iron chelators (deferoxamine and phenanthroline) and phenolic antioxidants (N,N'-diphenyl-phenylenediamine, butylated hydroxyanisole, and butylated hydroxytoluene). At low concentrations (＜1.0 mM), t-BHP inhibited glutamate uptake without altering lipid peroxidation. Moreover, a large increase in lipid peroxidation by $ascorbate/Fe^{2+}$ was not accompanied by an inhibition of glutamate uptake. The impairment of glutamate uptake by t-BHP was not intimately related to the change in $Na^+-K+-ATPase$ activity. These results suggest that inhibition of glutamate uptake by t-BHP is not totally mediated by peroxidation of membrane lipid, but is associated with direct interactions of glutamate transport proteins with t-BHP metabolites. The $Ca^{2+}$ influx through $Ca^{2+}$ channel or $PLA_2$ activation may not be involved in the t-BHP inhibition of glutamate transport.

• 약학회지
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• 제53권6호
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• pp.314-320
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• 2009

We examined metabolic conversion of cysteine into glutathione (GSH) and taurine in rat liver under oxidative stress. Administration of tert-butylhydroperoxide (t-BHP) into the portal vein of male rats resulted in a rapid elevation of serum sorbitol dehydrogenase, alanine aminotransferase, and aspartate aminotransferase activities, which decreased gradually in 24 hr. Hepatic cysteine concentration was reduced in 3 hr, and recovered progressively, reaching a level greater than 200% of the normal value in 24 hr. GSH was increased both in liver and blood at 9 hr after t-BHP challenge, whereas hypotaurine or taurine was not altered. $\gamma$-Glutamylcysteine synthetase (GCS) activity was increased from 9 hr after t-BHP treatment, but protein expression of the GCS-heavy subunit was not changed in liver. Activity or expression of cysteine dioxygenase was not affected by t-BHP treatment. Taken together, these data show that an acute oxidant challenge to the rats may induce upregulation of cysteine availability and GCS activity, resulting in an enhancement of hepatic GSH synthesis, but the increased cysteine level does not stimulate taurine synthesis via cysteine sulfinate pathway. It is indicated that the regulation of GSH and taurine biosynthesis from cysteine is not solely dependent on the cysteine concentration in rat liver under oxidative stress.

• 대한약침학회지
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• 제2권1호
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• pp.13-25
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• 1999

This study was undertaken to determine whether Juglandis Semen (JAS) extraction exerts protective effect against oxidant-induced inhibition of $Na^+$-pump activity in cerebral cortex. $Na^+$-pump activity was estimated by measuring ouabain-sensitive oxygen consumption. The oxygen consumption significantly inhibited by 1 mM t-butylhydroperoxide (tBHP), which was prevented by addition of 2% JAS extraction. The oxygen consumption was increased by an increase in $Na^+$ concentration from 5 to 100mM, $K^+$ concentration from 0.5 to 10 mM, and $Mg^{++}$ concentration from 0.2 to 5 mM. These changes in ion concentrations did not affect the inhibitory effct of tBHP and protective action of JAS on oxygen consumption. tBHP(1mM) produced a significant increase in lipid peroxidation in cerebral cortex, which was prevented by 2% JAS extraction. These result suggest that JAS exerts protective effect against tBHP-induced inhibition of $Na^+$-pump activity in the cerebral cortex, this effect may be due to by an antioxidant action.

• Journal of Acupuncture Research
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• 제22권5호
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• pp.151-160
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• 2005

Objectives : This study was undertaken to examine whether Juglandis Semen herbal acupuncture (JGA) exerts protective effect against oxidant-induced cell injury in rabbit liver. Methods : The cell damage was estimated by measuring lactate dehydrogenase (LDH) release, and lipid peroxidation was estimated by measuring malondialdehyde (MDA) in rabbit liver slices. Results : t-Butylhydroperoxide (tBHP) caused an increase in LDH release and lipid peroxidation in a dose-dependent manner over concentrations of 0.5-2 mM, which were prevented by addition of 0.05% JGA. The protective effect of JGA was dose-dependent in concentration range of 0.005 to 0.1%. The concentrations of 0.005 and 0.1% JGA completely prevented the LDH release and lipid peroxidation by 1 mM tBHP. When liver tissues were exposed to 1 mM tBHP, alanine aminotransferase (ALT) activity in the medium was significantly increased, which was prevented by 0.05% JGA. tBHP (2 mM) decreased GSH content and the effect was prevented by 0.05% JGA. Conclusion : These results suggest that JGA exerts protective effect against oxidant-induced cell injury by antioxidant action resulting from enhancement of GSH content in the liver.

• Journal of Acupuncture Research
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• 제18권2호
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• pp.150-160
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• 2001

Objectives ; This study was undertaken to determine whether Carthami-Flos aquacapuncture (CFA) exerts protective effect against oxidant-induced inhibition of $Na^+-K^+$-ATPase activity in cerebral synaptosomes. Methods and Results ; The enzyme activity was dependent on incubation time and enzyme protein concentrations. An oxidant t-butylhydroperoxide (tBHP) at 1 mM concentration caused a significant inhibition of $Na^+-K^+$-ATPase activity, which was prevented by addition of 0.01% CFA. tBHP inhibition and CFA protection were independent on incubation time or enzyme protein concentrations. The enzyme activity was increased by ATP in a dose dependent manner. Effects of tBHP and CFA were not affected by ATP cocentrations. tBHP (1 mM) produced a significant increase in lipid peroxidation in cerebral synaptosomes, which was prevented by 0.01% CFA. CFA decreased oxygen free radicals generated induced by the phorbol-ester in a dose-dependent manner in human neutrophil. Conclusions ; These results suggest that CFA exerts protective effect against tBHP-induced inhibition of $Na^+-K^+$-ATPase activity, which is due to by an antioxidant action resulting from a direct scavenging effect of oxygen free radicals in the cerebral synaptosomes.

• Journal of Acupuncture Research
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• 제20권6호
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• pp.128-139
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• 2003

Juglans sinensis Dode has been reported to have antioxidant activity. However, the effect of Juglans sinensis Dode aquacupuncture(JS) on reactive oxygen species(ROS)-induced alterations in membrane transport function in renal tubular cells. This study was performed to evaluate the effect of JS on the organic hydroperoxide t-butylhydroperoxide(tBHP)-induced inhibition of $Na^+$-dependent phosphate($Na^+$-Pi) uptake in opossum kidney (OK) cells, an established renal proximal epithelial cell line. tBHP inhibited $Na^+$-Pi uptake in a time-dependent manner. The inhibitory effect of tBHP was prevented by JS over concentration range of 0.05-1mg/100ml in a dose-dependent manner. Kinetic studies showed that tBHP caused an decrease in Vmax for $Na^+$-Pi uptake without any a significant change in Km. $Na^+$-dependent phosphonoformic acid binding, a irreversible inhibitor of renal $Na^+$-Pi uptake, was decreased by tBHP treatment. The reduction in Vmax and phosphonoformic acid binding by tBHP was prevented by JS. tBHP induced lipid peroxidation and its effect was completely inhibited by JS and antioxidant N,N'-diphenyl-p-phenylenediamine. These data suggest that the oxidant inhibits phosphate uptake by a reduction in the number of active carrier across the membrane. JS may prevent oxidant-induced inhibition of membrane transport function by a mechanism similar to antioxidants in renal epithelial cells. Although the precise constituents remain to be explored, JS may be employed as a useful candidate herb for drug development to prevent and treat oxidant-mediated renal failure.

• 대한한방내과학회지
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• 제25권4호
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• pp.75-85
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• 2004

목적 : 黃芩(황금)과 黃芩(황금)의 주요 flavonoid 성분인 baicalein이 신장세뇨관 상피세포에서 산화제에 의한 apoptosis에 미치는 효과를 살펴보고자 한다. 방법 : 신장세뇨관 상피세포주인 opossum kidney (OK) 세포를 유기산화제인 t-butylhydroperoxide (tBHP)에 노출시켜 apoptosis를 일으킨 후 관련된 변화를 관찰하였다. 결과 : tBHP는 농도에 의존하여 apoptosis를 유발시켰는데, 이러한 효과는 黃芩(황금)과 baicalein에 의해 농도 의존적으로 방지 되었다. tBHP에 의한 OK 세포사는 항산화제인 Trolox와 N-acetylcysteine에 의해 방지 되었다. tBHP는 mitogen-activated protein kinase의 subfamily인 extracellular signal-regulated kinase (ERK)를 활성화시켰다. ERK 억제제인 PD98059와 U0126은 tBHP에 의한 세포 사망을 방지하였다. tBHP에 의한 ERK 활성화는 U0126에 의해 억제되었으나 黃芩(황금)과 baicalein에 의해서는 영향을 받지 않았다. 철착염제인 deferoxamine은 tBHP에 의한 세포 사망과 ERK 활성화를 방지하였다. tBHP에 의한 세포 사망은 casopase 억제제인 BOD-U-FMK와 zDEVD-FMK에 의해 방지되었다. 결론 : 黃芩(황금)은 산화제에 의한 세포 사망을 방지하는데, 이는 kinase 억제, 항산화제 역할 및 철착염제의 작용에 기인하지 않았다. 黃芩(황금)의 이러한 효과는 산화제에 의관 신부전 예방 및 치료제로 개발하는데 이용될 수 있는 가능성을 보였다.

• 생약학회지
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• 제37권4호
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• pp.272-277
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• 2006

This study was undertaken to determine whether Juglandis Semen (JAS) extract exerts protective effect against oxidant-induced inhibition of $Na^+-pump$ activity in cerebral cortex. $Na^+-pump$ activity was estimated by measuring ouabain-sensitive oxygen consumption. The oxygen consumption significantly inhibited by 1mM t-butylhydroperoxide (tBHP), which was prevented by addition of 2% JAS extract. The oxygen consumption was increased by an increase in $Na^+$ concentration from 5 to 100 mM, $K^+$ concentration from 0.5 to 10 mM, and $Mg^{2+}$ concentration from 0.2 to 5 mM. These changes in ion concentrations did not affect the inhibitory effect of tBHP and protective action of JAS on oxygen consumption. tBHP (l mM) produced a significant increase in lipid peroxidation in cerebral cortex, which was prevented by 2% JAS extraction. These results suggest that JAS exerts protective effect against tBHP-induced inhibition of $Na^+-pump$ activity in the cerebral cortex, probably through action as antioxidant.

• Journal of Acupuncture Research
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• 제18권2호
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• pp.101-110
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• 2001

Objective : This study was undertaken to determine if Scutellaria baicalensis Georgi (SbG) extract exerts protective effect against oxidant-induced cell injury in renal proximal tubular cells. Methods : The cell injury was evaluated by lactate dehydrogenase (LDH) release in rabbit renal cortical slices and lipid peroxidation was estimated by measuring malondialdehyde (MDA). t-Butylhydroperoxide (tBHP) was used as a model of oxidant. Results : tBHP at 1 mM increased LDH release and lipid peroxidation, which were prevented by SbG in a dose dependent manner over concentration range of 0.001-0.1%. SbG provided the protective effect against oxidant-induced reduction in PAH uptake by renal cortical slices and microsomal Na+-K+-ATPase activity. SbG attenuated tBHP-induced depletion of reduced glutathione. 0.2 mM $HgCl_2$ increased LDH release and lipid peroxidation, which were completely prevented by 0.05% SbG. Conclusion : SbG prevents oxidant-induced impairment in membrane transport function.