• Archives of Pharmacal Research
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• v.16 no.1
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• pp.13-17
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• 1993

Several naturally occurring furanocoumarins significantly inhibited microsomal lipid peroxidation not only mediated by endogeneous iron and NADPH but also initiated by $CCL_4$ metabolites, phellopterin, a potent inhibibitor of cytochrome p-450, exhibited an almost complete inhibition of $CCL_4$-induced hepatotoxicity as measured by sGPT activity 24 hr after $CCL_4$ intoxication, whereas other furanocoumarins such as imperation, byakangelicin and oxypeucedanin methanolate exerted no protective effect. When compared with other cytochrome P-450 inhibitors(SKF-52A, AIA) and silymarin given at the same dose level $(ED_{50})$, phellopterin still showed a significant inhibition of hepatotoxicity which was even stronger than that of AIA, known as a typical suicide inhibitor. Phellopterin was partially effective when given 30 min after $CCL_4$ treatment. Repeated administrations of phellopterin, however, resulted in a complete loss of the protection against $CCL_4$-induced hepatotoxicity.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.940-945
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• 2002

The present study was done to determine the effect of trolox C, a hydrophilic analogue of vitamin E, on hepatic injury, especially the alteration in cytochrome P-450 (CYP)-dependent drug metabolism during ischemia and reperfusion (I/R). Rats were subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Rats were treated intravenously with trolox C (2.5 mg/kg) or vehicle (PBS, pH 7.4), 5 min before reperfusion. Serum alanine aminotransferase and lipid peroxidation levels were markedly increased after I/R. This increase was significantly suppressed by trolox C. Cytochrome P-450 content was decreased after I/R but was restored by trolox C. There were no significant differences in ethoxyresorufin O-dealkylase (CYP 1A1) and methoxyresorufin O-dealkylase (CYP 1A2) activities among any of the experimental groups. Pentoxyresorufin O-dealkylase (CYP 2B1) activity was decreased and aniline p-hydroxylase (CYP 2E1) activity was increased after I/R. Both these changes were prevented by trolox C. Our findings suggest that trolox C reduces hepatocellular damage as indicated by abnormalities in microsomal drug-metabolizing function during I/R, and that this protection is, in part, caused by decreased lipid peroxidation.

• Journal of Environmental Science International
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• v.13 no.8
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• pp.711-719
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• 2004

The effect of nickel (Ni) on growth and some tolerance strategies with regard to heavy metal tolerance mechanism was investigated in radish (Raphanus sativus) seedlings. The protective effect of histidine on nickel stress conditions was also monitored. The seedling growth decreased with an increase in metal concentrations. The inhibitory effect was more pronounced in the root elongation than in the shoot elongation. Increasing Ni supply showed a progressive increase of Ni concentrations in the roots and shoots. Ni content was higher in the shoots than in the roots. In the presence of nickel, radish exhibited an antioxidative defense mechanism, as evidenced by the elevated malondialdehyde(MDA), showing that nickel is an efficient inducer of lipid peroxidation. Exposure of radish to elevated concentrations of nickel was accompanied by an increase in the proline content. Supplemental histidine in the presence of Ni ameliorated metal-induced growth inhibition and lipid peroxidation. Combinations of Ni and histidine resulted in a significant decline in proline content compared with Ni stress alone, indicating that histidine may provide protection against the adverse effect of Ni stress. From the results it is suggested that histidine is an efficient chelator by complexing metal ion within the plant and may playa role in nickel tolerance implicated in metal detoxification.

• Environmental Analysis Health and Toxicology
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• v.3 no.3_4
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• pp.39-51
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• 1988

Effects of ${\alpha}$-tocopherol and perilla oil on the toxicity of polychlorinated biphenyls (PCB) in male rat were studied. Rats were fed ad libitum for 6 weeks with the animal diet which contains PCB 30 ppm and 100 ppm. Perilla oil (0.5 g/kg body weight) and ${\alpha}$-tocopherol (30 mg/kg body weight) were administered intraperitoneally twice a week for 6 weeks. Rats fed with PCB showed enlargement of liver and spleen, increase in aspartate aminotransferase, alkaline phosphatase, sereum lipid and cytochrome P 450 and decrease in body weight and glutathione. When perilla oil was administered to rats fed with PCB increase in aspartate aminotransferase, alkaline phosphatase, serum lipid and cytochrome P45O and decrease in body weight and glutathione were significantly augmented, compared to rats fed with PCB alone. This means that perilla oil potentiates the toxicity of PCB. On the other hand when ${\alpha}$-tocopherol was administered to rats fed with PCB increase in aspartate aminotransferase, alkaline phosphatase, serum lipid and cytochrome P45O and decrease in body weight and glutathione were signigicantly reduced, compared to rats fed with PCB alone. This means that u-tocopherol reduces the toxicity of PCB. From the above results, it may be concluded that PCB is metabolized by microsomal mixed function oxidase and the metabolite causes the toxicity and microsomal glutathione plays a role of protection on the toxicity of PCB.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.137-141
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• 2008

The present study reports the protective properties of a total methanol extract of B. platyphylla var. japonica against ultraviolet (UV)-C irradiation. Pretreatment of Chinese hamster fibroblast (V79-4) cells with a total methanol extract significantly increased cell survival following $300\;J/m^2$ of UV-C irradiation. The total methanol extract was further fractionated into 5 fractions: n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these fractions, B. platyphylla var. japonica ethylacetate, butanol and water fractions showed significant protective effects against the cellular damage induced by UV-C irradiation. In order to elucidate the mechanism underlying this protective effect, DPPH (Editor note: abbreviations should be spelled out at first use.) radical scavenging and lipid peroxidation inhibitory activity were measured. Significant radical scavenging and lipid peroxidation inhibitory activities were observed for the ethylacetate fraction. In summary, the present data demonstrate that an extract of B. platyphylla var. japonica has a significant protective effect against UV-C irradiation. The underlying mechanism of this protective effect may involve radical scavenging and inhibition of lipid peroxidation by the B. platyphylla var. japonica extract.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.232-238
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• 2004

Trolox is a hydrophilic analogue of vitamin E. The aim of this study was to investigate its effects on hepatic injury, especially alteration in cytochrome P450 (CYP)-dependent drug metabolism during polymicrobial sepsis. Rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). The rats were treated intravenously with Trolox (2.5 mg/kg) or vehicle, immediately after CLP. Serum aminotransferases and lipid peroxidation levels were markedly increased 24 h after CLP. This increase was attenuated by Trolox. Total CYP content and NADPH-P450 reductase activity decreased significantly 24 h after CLP. This decrease in CYP content was attenuated by Trolox. At 24 h after CLP, there was a significant decrease in the activity of these CYP isozymes: CYP1A1, 1A2, 2B1, and 2E1. However, Trolox differentially inhibited the decrease in CYP isozyme activity. Trolox had little effect on the decrease in CYP1A1 activity but Trolox significantly attenuated decreases in CYP1A2 and 2E1 activities. In fact, Trolox restored CYP2B1 activity to the level of activity found in control rats. Our findings suggest that Trolox reduces hepatocellular damage as indicated by abnormalities in hepatic drug-metabolizing function during sepsis. Our data also indicates that this protection is, in part, caused by decreased lipid peroxidation.

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.85-90
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• 1996

It has been suggested that oxygen-derived free radicals play an important role in the pathophysiology of acute gastric ulceration induced by NSAIDs and ischemia-reperfusion. Taurine is hypothetized to exert its protective effect on NSAIDs-induced gastric injury by its antioxidant properties. Protective effect of taurine on indomethacin-induced gastric mucosal lesion and its protection mechanism were investigated. Intragastric administration of 25 mg/kg of indomethacin induced hemorrhagic lesions on the glandular stomach in rats. Pretreatment with 0.25 or 0.5 g/kg of taurine one day before or for 3 days significantly reduced the gastric lesion formation and inhibited the elevation of lipid peroxide level in gastric mucosa. The luminol-dependent chemiluminescence of rat peritoneal neutrophils increased immediately after treatment of FMLP or indomethacin. Taurine (5-20 mM) inhibited chemiluminescence of neutrophils activated by FMLP. Human neutrophils (polymorphonuclear leukocytes) significantly adhered to the confluent monolayer of human umbilical vein endothelial cells (HUVEC) after coincubation with indomethacin. This neutrophil adhesion induced by indomethacin to HUVEC was prevented by taurine in a dose-dependent manner. These results indicate that the protective effect of taurine against NSAIDs-induced gastric mucosal injury is due to its antioxidant effect, which inhibits lipid peroxidation and neutrophil activation.

• YAKHAK HOEJI
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• v.47 no.2
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• pp.85-92
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• 2003

Seok-jeong (SJ) is a solution of various metal ions and numerous other organic substances produced through extraction and fermentation of herbs and soil using geo-microbes, and it has been shown to improve symptoms of senile dementia. In this study, we investigated the protective effects of SJ against neurotoxicity of cadmium in HT22 hippocampal neuron cell line. SJ significantly protected from the cadmium-induced decreased cell viability measured by MTT assay (p＜0.01). The protective effects of SJ against cadmium toxicity were confirmed through observing morphological changes using inverted microscope. Additionally, SJ significantly repressed the formation of lipid peroxidation induced by high concentration of cadmium, and likewise, significantly repressed the reduction of glutathione by cadmium in HT22 cells. Vitamin C at the concentration found in SJ did not show any protective effect against cadmium toxicity in HT22 cells, indicating that vitamin C may not have a major role in the protective mechanism of SJ. Taken together, these results suggest that SJ may be a valuable agent for the protection of cadmium toxicity on the neuronal cells, and that the mechanism of the action of SJ may be due to reduced lipid peroxidation and increased glutathione level.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.5
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• pp.403-411
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• 2021

This study was designed to evaluate the gastroprotective activity of cirsilineol in hydrochloric acid (HCl)/ethanol-induced gastric ulcer model. Cirsilineol was administered at the doses of 20 and 40 mg/kg in HCl/ethanol-induced rats. The gastroprotective ability was verified by determining the ulcer score, total acidity, hemoglobin, inflammatory cytokines, lipid peroxides, and enzymatic antioxidants superoxide dismutase (SOD) and catalase (CAT) in gastric tissue and serum biochemical analysis. The results showed a favorable increase in the hemoglobin level, antioxidant enzymes (SOD and CAT), restored electrochemical balance (carbon dioxide & anion gap) while a noticeable decrease in ulcer index, total acidity, lipid peroxides, inflammatory cytokines (interleukin-1 beta [IL-1β], IL-6, and tumor necrosis factor alpha) in rats treated with the cirsilineol. The serum biochemical analysis on liver markers (alkaline phosphatases, alanine aminotransferase, and aspartate aminotransferase), kidney markers (urea, creatinine, albumin, globulin, total protein), and lipid profile (triglyceride, high-density lipoprotein, total cholesterol) were attenuated by cirsilineol treatment in rats. Histopathology showed enhanced gastric protection and preserved the integrity of gastric mucosa upon cirsilineol administration. These results ultimately suggest that cirsilineol has gastroprotective effects that prevent the development of gastric ulcer.

• Journal of Ginseng Research
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• v.47 no.4
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• pp.572-582
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• 2023

Background: Free fatty acid-induced lipotoxicity is considered to play an important role in pancreatic β-cell dysfunction. The effect of ginsenosides on palmitic acid-induced pancreatic beta-cells cell death and failure of glucose-stimulated secretion of insulin (GSIS) was evaluated in this study. Methods: Enzyme-linked immunosorbent assay kit for a rat insulin was used to quantify glucose-stimulated insulin secretion. Protein expression was examined by western blotting analysis. Nuclear condensation was measured by staining with Hoechst 33342 stain. Apoptotic cell death was assessed by staining with Annexin V. Oil Red O staining was used to measure lipid accumulation. Results: We screened ginsenosides to prevent palmitic acid-induced cell death and impairment of GSIS in INS-1 pancreatic β-cells and identified protopanaxadiol (PPD) as a potential therapeutic agent. The protection effect of PPD was likely due to a reduction in apoptosis and lipid accumulation. PPD attenuated the palmitic acid-induced increase in the levels of B-cell lymphoma-2-associated X/B-cell lymphoma 2, poly (ADP-ribose) polymerase and cleaved caspase-3. Moreover, PPD prevented palmitic acid-induced impairment of insulin secretion, which was accompanied by an increase in the activation of phosphatidylinositol 3-kinase, peroxisome proliferator-activated receptor γ, insulin receptor substrate-2, serine-threonine kinase, and pancreatic and duodenal homeobox-1. Conclusion: Our results suggest that the protective effect of PPD on lipotoxicity and lipid accumulation induced by palmitic acid in pancreatic β-cells.