• The Journal of Korean Society for Radiation Therapy
• /
• v.12 no.1
• /
• pp.166-173
• /
• 2000

Angiopoietin-1(Ang-1) is a vasculogenic factor that signals through the endothelial cell-specific Tie2 receptor tyrosine kinase. We examined the effect of angiopoietin-1(Ang-1) on radiation-induced apoptosis in human umbilical vein endothelial cells(HUVECS) and receptor/second messenger signal transduction pathway for Ang-1's effect on HUVECs. The percent of apoptotic cells under control condition(0Gy) was $8.2\%$. Irradiation induced apoptosis was increased in a dose(1, 5, 10, and 15Gy)- and time 12, 24, 48 and 72hr)-dependent manner. The percent of apoptotic cells was approximately $34.9\%$ after 15 Gy of irradiation. Under these conditions, pretreatment with Ang-1's (50, 100, 200, and 400 ng/ml) inhibited irradiation-induced apoptosis in human umbilical vein endothelial cells in a dose-dependent manner. Two hundred ng/ml of Ang-1 inhibited approximately $55-60\%$ of the apoptotic events that occurred in the 10 Gy-irradiated cells. Pre-treatment with soluble Tie2 receptor, but not Tie1 receptor, blocked the Ang-1's antiapoptotic effects. Phosphatidylinositol 3'-kinase (P13-kinase) specific inhibitor, wortmanin and LY294002, blocked the Ang-1-induced antiapoptotic effect. Ang-1 promotes the survival of endothelial cells in irradiation-induced apoptosis through Tie2 receptor binding and P13-kinase activation. Pretreatment of Ang-1 could be beneficial in maintaining normal endothelial cell integrity during irradiation therapy.

• Applied Microscopy
• /
• v.26 no.3
• /
• pp.315-328
• /
• 1996

This study aims to demonstrate the effect of SOD (superoxide dismutase), one of the antioxidant enzymes, on the ultrastructural changes in the parietal cells caused by the administration of cisplatin in the rat. A total of 60 healthy Sprague-Dawley rats weighing about 200 gm were used as experimental animals. Cisplatin (6 mg/kg) was administered intraperitoneally to rats pretreated with 15,000 unit/kg of SOD or rats without the pretreatment. The experimental animals were sacrificed at 6 hours, 12 hours, 24 hours and 3 days after the administration of cisplatin. The results were as follows: 1. SOD alone did not affect the ultrastructural changes in the gastric parietal cells in the rat. 2. Irregular shaped mitochondria, mitochondria with dim cristae, dilated cristae, ruptured outer membrane, electron lucent matrix and degenerative mitochondria were seen in cisplatin treated rat. Whorled membranous body, many lysosomes and large vacuole were observed in the gastric parietal cells in cisplatin treated rat. 3. Mitochondria with dilated cristae and electron lucent matrix and irregular shaped mitochondria were observed in the gastric parietal cells of the cisplatin treated rat with pretreatment of SOD. These results suggest that SOD attenuates the toxic effect of the cisplatin in the gastric parietal cells of the rat.

• Journal of Pharmaceutical Investigation
• /
• v.24 no.3
• /
• pp.41-47
• /
• 1994

The effect of Azone and ethanol on the electrical properties of human and hairless mouse skin was studied and the results were compared. The complex electrical impedance was measured as a function of frequency, and resistance and capacitance were determined from Nyquist plot. After the treatment of human-heat separated epidermis with Azone, contrary to the expectation, resistance increased about 60% and it did not change with time. Capacitance also increased; immediately after the treatment, it was about 110% of pretreatment value and it increased further with time. On the other hand, when hairless mouse skin was treated with Azone, marked changes occured; resistance fell almost to the value of bathing medium itself and capacitance increased to about 200% of its pretreatment value. Similar result were obtained when hairless mouse skin was treated with 100% ethanol. The results suggest that there are differences in the strength of barrier properties of stratum corneum (SC) between human and hairless mouse skin. Overall, the results provide further mechanistic insight into ion conduction through the skin and into the role of SC lipids in skin capacitance.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.26 no.4
• /
• pp.441-445
• /
• 2012

Cadmium is an important occupational and environmental pollutant that damages various organs, especially renal proximal tubular cells. We examined the effect of aqueous extract of Buddleja officinalis (ABO) on cadmium chloride ($CdCl_2$)-induced cytotoxicity in HK-2 human renal proximal tubular cells. HK-2 cells were preincubated with ABO (50, 100, 200 and 400 ${\mu}g/ml$) for 3 hr and then treated with 10 ${\mu}M$ $CdCl_2$ for 24 hr. The effect of ABO on $CdCl_2$-induced cytotoxicity in HK-2 cells was investigated by using MTT assay, morphological observation, flow cytometric analysis and Western blot. The results of the MTT assay and morphological observation indicated that $CdCl_2$-induced cytotoxicity was prevented by pretreatment with ABO. In flow cytometric analysis, ABO reduced sub-G1 peak (apoptotic peak) in $CdCl_2$-treated cells. $CdCl_2$-induced procaspase-3 proteolysis and PARP cleavage reduced by pretreatment with ABO. These results suggest that ABO effectively inhibited $CdCl_2$-induced cytotoxicity in HK-2 cells.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2002.10a
• /
• pp.173-173
• /
• 2002

In order to understand the mechanism of action of TCDD, we have examined the effect of COX-inhibitors on cyp1a1 activity. We observed the effect of COX-inhibitor on EROD activity in C57BL/6 mouse in vovo. And we also evaluated the effect of COX-inhibitors on cyp1a1 mRNA, mouse cyp1a1 promoter activity and EROD activity in Hepa cell. When Aspirin were pretreated with 3MC in vivo, the EROD activity that was stimulated by 3MC was inhibited. And Pretreatment of Aspirin, Celecoxib, Nimesulide and other several Cox-inhibitors in vitro, inhibited the TCDD stimulated EROD activity and Luciferase acitivity. In case of cyp1a1 mRNA level, Nimesulide and SB100 were able to decrease cyp1a1 mRNA that was stimulated by TCDD, but other tested COX-inhibitors were not decrease. We don't know this different result exactly. For the action of Cox-inhibitors on the Cyp1a1, it seems to be important to do pretreatment of these chemicals as apposed to TCDD. In this study, thus, we have suggested that COX-inhibitors such as aspirin, celecoxib, Nimesulide and other several Cox-inhibitors decrease the TCDD induced Cyp1a1.

• Korean Journal of Veterinary Research
• /
• v.39 no.4
• /
• pp.710-714
• /
• 1999

In veterinary medicine amitraz has been used as an insecticide to eliminate mites, lice, and ticks in dogs, cats, goats, swine and cattle. We performed the experiment on bradycardiac effect of arnitraz in rabbits. Under anesthetized with urethane (1g/kg, 25% w/v, SC), the femoral artery was cannulated by a polyvinyl tube which was connected with pressure transducer for continuous measurement of heart rate. Amitraz (0.5-2.5mg/kg, IV) reduced the heart rate in a dose-dependent manner. Pretreatment of yohimbine (2.0mg/kg) or atropine (2.0mg/kg and 4.0mg/kg) affected the response of amitraz but pretreatment of prazosin (0.5mg/kg) or propranolol (1.0mg/kg) did not. Moreover, the effect of amitraz was blocked by vagotomy. The result of our experiment suggest that amitraz may reduce the heart rate by increasing acetylcholine through activating vagal nerves and ${\alpha}_2$-adrenoceptors could be involved in activating vagal nerves.

• Advances in Traditional Medicine
• /
• v.8 no.1
• /
• pp.24-31
• /
• 2008

In the present investigation, we studied the effect of alcoholic extract of Moringa oleifera (M. oleifera) seed kernels on various experimental models of bronchial asthma. Significant (P < 0. 05) increase in preconvulsion time was observed due to pretreatment with M. oleifera when the guinea pigs were exposed to either acetylcholine (Ach) or histamine aerosol. This bronchodilating effect of M. oleifera was comparable to ketotifen fumarate. Spasmolytic effect of M. oleifera was also observed by dose dependent inhibition of ideal contractions induced by Ach, 5HT, histamine and $BaCl_2$. Alcoholic extract of M. oleifera produced significant dose dependent protection by egg albumin and compound 48/80 induced mast cell degranulation. Pretreatment with alcoholic extract of M. oleifera also decreased carrageenan induced rat paw edema, which was comparable to that of standard diclofenac sodium. Minimum inhibitory concentration for alcoholic extract of M. oleifera was low as compared to cold-water extract and hot water extract when antimicrobial activity was tested against various respiratory pathogens like Escherichia coli (E. coli), Staphylococus aureus (S. aureus) and pseudomonas aeruginosa (P. aeruginosa). Our data suggest that antiasthmatic activity of M. oleifera seed kernels may be due to its bronchodilator, anti-inflammatory, mast cell stabilization and antimicrobial activity.

• Journal of Ginseng Research
• /
• v.22 no.1
• /
• pp.1-10
• /
• 1998

In the present study, to determine whether the antioxidative components of Korean red ginseng protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of total saponin (200 mg/kg, ip) and lipophilic fraction (200 mg/kg, oral) preferment of mice on the survival ratio, major antioxidant enzymes (SOD, catalase and glutathione peroxidase) activities, glutathione levels and lipid peroxidation in the liver were exiled for 2 weeks after whole ${\gamma}$-body ${\gamma}$-irradiation (6.5 Gy). The 30-day survival ratio increased from 10% to 57% and 40% for mice treated with total saponin and lipophilic fraction, respectively. On day 14 after ${\gamma}$-irradiation, the ginseng total saponin pretreatment produced a slight increase of antioxidant enzymes activities and significantly Increased reduced glutathione (GSH) contents (p<0.05) in the liver compared with non-treated group. Pretreatment with ginseng total saponin significantly deceased GSSG/total GSH ratio (p<0.05) without change of GSSG in the liver and inhibited the radiation-induced incense in the hepatic malondialdehyde levels. (p<0.05) In these results, GSH plays an important role in the liver in several detoxifications and the reduction of lipid peroxides. Thus, it appears that total saponin of red ginseng exerts its radioprotective effect by accelerating the production of endogenous antioxidants, such as glutathione from radiation induced damages and thereby oxygen free radicals.

• YAKHAK HOEJI
• /
• v.40 no.5
• /
• pp.574-581
• /
• 1996

The study was initiated to elucidate the protective mechanism by examining in vivo effect of some marine natural products, Styela plicata, Ecklonia stolonifera and Pachymeniopsis elliptica on acetaminophen-induced lipid peroxidation. The methanol extract of S. plicata prevented acetaminophen (800mg/kg, i.p.)-induced hepatotoxicity in rats as evidenced by the decreased formation of lipid peroxide. But the methanol extracts of E. stolonifera and P. elliptica were not affected on the formation of lipid peroxidation. The activities of cytochrome P-450, animopyrine N-demethylase and aniline hydroxylase were not changed by the treatment with S. plicata in comparison with acetaminophen-teated group. In acetaminophen-treated control rats, the glutathione S-transferase activity was decreased markably. However. in S. plicata pretreated group, the effect caused by acetaminophen was markably reduced. A-cetaminophen decreased the level of hepatic, glutathione, which was restored to same degree by S. plicata pretreatment. And activity of ${\gamma}$-glutamylcystein synthetase was not changed by S. plicata pretreatment, but the activity of glutathione reductase was increased significantly.

• The Journal of Korean Medicine
• /
• v.21 no.3
• /
• pp.119-128
• /
• 2000

This study was carried out to determine if Salviae Radix extract (SRE) exerts protective effect against alterations in membrane transport function in rabbits with rhabdomyo lysis-induced acute renal failure. Acute renal failure was induced by intramuscular administration of glycerol (50%, 10 ml/kg). GFR in the glycerol-injected animals was reduced to 11% of the basal value and the fractional $Na^{+}$ excretion was increased to 7.8-fold, indicating generation of acute renal failure. When animals received SRE pretreatment for 7 days prior to glycerol injection, such changes were significantly attenuated. The fractional excretion of glucose and phosphate was increased more than 43-fold and 27-fold, respectively, in rabbits treated with glycerol alone. However, they were increased to 17-and 4.3-fold, respectively, in SRE-pretreated rabbits, and these values were significantly lower than those in rabbits treated with glycerol alone. Uptakes of glucose and phosphate in purified isolated brush-border membrane, the $Na^{+}-K^{+}-ATPase$ activity in microsomal fraction, and cellular ATP levels all were reduced in rabbits treated with glycerol alone. Such changes were prevented by SRE pretreatment. Uptakes of organic ions, PAH and TEA, in renal cortical slices were inhibited by the administration of glycerol, which was prevented by SRE pretreatment. Pretreatment of an antioxidant DPPD significantly attenuated the increase in the fractional excretion of glucose and phosphate induced by rhabdomyolysis. These results indicate that rhabdomyolysis causesimpairment inreabsorption of solutes in the proximal tubule via the generation of reactive oxygen species, and SRE pretreatment may provide the protection against the rhabdomyolysis-induced impairment by its antioxidant action.