• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.12
• /
• pp.4745-4751
• /
• 2014

Oxidative stress is caused by an imbalance in the redox status of the body. In such a state, increase of free radicals in the body can lead to tissue damage. One of the most important species of free radicals is reactive oxygen species (ROS) produced by various metabolic pathways, including aerobic metabolism in the mitochondrial respiratory chain. It plays a critical role in the initiation and progression of various types of cancers. ROS affects different signaling pathways, including growth factors and mitogenic pathways, and controls many cellular processes, including cell proliferation, and thus stimulates the uncontrolled growth of cells which encourages the development of tumors and begins the process of carcinogenesis. Increased oxidative stress caused by reactive species can reduce the body's antioxidant defense against angiogenesis and metastasis in cancer cells. These processes are main factors in the development of cancer. Bimolecular reactions cause free radicals in which create such compounds as malondialdehyde (MDA) and hydroxyguanosine. These substances can be used as indicators of cancer. In this review, free radicals as oxidizing agents, antioxidants as the immune system, and the role of oxidative stress in cancer, particularly breast cancer, have been investigated in the hope that better identification of the factors involved in the occurrence and spread of cancer will improve the identification of treatment goals.

• Journal of Life Science
• /
• v.6 no.1
• /
• pp.48-55
• /
• 1996

Oxygen free radicals are highly reactive molecules with unpaired electrons, which are produced with in aerobic cells in the course of normal metabolic events. Normally, aerobic cells are protected from the damage of free radicals by antioxidative enzymes such as superoxide dismutase (SOD), catalase, glutathione (GSH) peroxidase, GSH S-transferase and GSH reductase which scabvenge free radicals as well as nonenzymatic antioxidants such as ceruloplasmin, albumin and nontioxidants in order to elucidate antioxidative mechanisms of red ginseng. The treatment with total saponin of red ginseng significantly devreased the contents of malondialdehyde and total free radicals in the liver. On the other hand, total saponin of red ginseng significantly increased the activities of SOD, catalase and GSH reductase and nonprotein-SH level. These results suggest that total saponin of red ginseng exerts an antioxidative effect by increasing endogenous antioxidants.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.381.2-381.2
• /
• 2002

There is now increasing evidence that free radicals and active oxygen species are involved in a variety of pathological events. often associated with ageing. Free radical-mediated cell damage and free radical attack on polyunsaturated fatty acids result in the formation of lipid radicals. These lipid radicals react readily with molecular oxygen to produce peroxy radicals responsible for initiating lipid peroxidation. The peroxidation of cellular membrane lipid can lead to cell necrosis and considered to be implicated in a number of pathophysiological conditions as well as in the toxicity of many xenobiotics. (omitted)

• Biomedical Science Letters
• /
• v.7 no.3
• /
• pp.99-102
• /
• 2001

Toluene is mainly metabolized in liver by oxidative pathway. Oxigen free radicals occur through the process of toluene metabolism Therefore it causes tissue and cell min by the oxygen free radicals from the metabolism of toluene. Melatonin acts as a highly efficient free radical scavenger that protects cells from damage by oxygen free radicals. To test this hypothesis, toluene hepatotoxicity was induced by an abdominal injection of toluene. To see if the melatonin protects the rat's liver, melatonin was administrated orally, at the time of each toluene injection. Aspartate aminotransferase(AST), alanin aminotransferase(ALT), latic dehydrogenase(LDH) and alkaline phosphatase(ALP) levels in serum were measured to estimate hepatic function. Malondialdehyde(MDA), which gives an indirect index of oxidative injury was also measured. Hippuric acid is the last metabolic Production of toluene was measured by HPLC. There were significantly higher in AST, ALT, LDH, MDA and hippuric acid in toluene group, but there were no significant difference in melatonin group except ALT and hippuric acid. There was significantly lower in ALP level in toluene group, but there was no significant difference melatonin group, suggesting a significant hepatotoxicity due to oxygen free radicals through the process of toluene metabolism Melatonin treatment significantly protected hepatic function and free radical-mediated injury in the liver against toluene-induced changes. Accordingly, this study shows that melatonin is helpful in protecting liver injury by acute toluene intoxication.

• The Journal of Korean Medicine
• /
• v.17 no.1 s.31
• /
• pp.21-36
• /
• 1996

This study was undertaken to examine the effect of Jwagyuyeum and Woogyuycum, being known to reinforce Kidney-yin and yang, on the activities of endogenous antioxidant enzymes and the production of oxygen free radicals in the liver and kidney tissues, Alterations in enzyme activities were observed after in vivo treatment in rats, Jwagyuyeum and Woogyuyeum caused a significant increase in the activities of superoxide dismutase(SOD) and catajase Jwagyuyeum significantly increased the activity of glutathione peroxidase in both liver and kidney, but the enzyme activity was not significantly altered by Woogyuyeum. Treatment in vitro of Jwagyuyeum and Woogyuyeum decreased the production of oxygen free radicals in a dose-dependent fashion. These results suggest that Jwagyuyeum and Woogyuyeum stimulate the activities of antioxidant enzymes and inhibit directly the production of oxygen free radicals. These effects of both herbs may contribute to prevent the oxygen free radical-induced impairment of cell function.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.12
• /
• pp.1695-1699
• /
• 2004

The antioxidant enzymes, lipid peroxidation and free radicals assessment were made of the effects of selenium, copper and magnesium on bovine endemic fluorosis under high fluoride, low selenium and low copper productive conditions. Thirty-two beef cattle were selected from high fluoride area, and randomly divided into four groups with eight cattle each as follows: (1) high fluoride control group (HFC); (2) supplemented group with 0.25 mg/kg selenium (HFSe); (3) supplemented group with 15 mg/kg copper (HFCu) and (4) supplemented group with 0.25 mg/kg selenium+15 mg/kg copper+1 mg/kg magnesium (HFSeCuMg) per day for 83 days. Moreover, eight beef cattle were selected from non-high fluoride area as normal control group. Blood samples were collected from cattle on 0 d, 30 d and 83 d respectively, to analyze the enzyme activities and concentration of GSH-px, CAT, SOD, MDA and free radicals. The results showed that the contents of free radicals and MDA in HFC group were significantly higher, and the whole blood GSH-px, CAT, erythrocyte SOD activities were lower than the normal control group. Free radicals, metabolic imbalance and antioxidant disorder therefore, play an important role in fluorosis. However, GSH-px, CAT and SOD activities in HFSe group and HFSeCuMg group at 30 d and 83 d were markedly higher than the same groups at the 0 d and the HFC group at the same time. Likewise, there was a corresponding reduction in the contents of free radicals and MDA. These findings indicated that supplementation with selenium, copper and magnesium elevated high fluoride bovine antioxidant enzymes, and decreased MDA and free radicals contents. But, the activities of supplementation selenium group did not increase until day 83. These results demonstrated that fluorosis was associated with lower serum Se and Cu levels than in the control, and it was therefore concluded that fluorosis is associated with decreased serum levels of these minerals. Long-term high fluoride intake under productive condition enhances oxidative stress in the blood, thereby disturbing the antioxidant defense of cattle. Increased oxidative stress could be one of the mediating factors in the pathogenesis of toxic manifestations of fluoride. It is benefical for high fluoride cattle supplemented with proper selenium, copper and magnesium to increase fluoride excretion and obtain the protective impact of the activity of oxidative enzymes, and to decrease lipid peroxidation and free radicals contents.

• Natural Product Sciences
• /
• v.16 no.3
• /
• pp.169-174
• /
• 2010

The seed of Phaseolus calcaratus Roxburgh (PHCR) is traditionally used for anti-pyretic and antiinflammatory effects. Although these effects are believed to be related to its antioxidant potential, little information is available for the mechanisms by which PHCR seed might scavenge free radicals or otherwise act as an antioxidant. In the present study, we purified some fractions from the ethanol extract of PHCR seed and evaluated each fraction's ability to scavenge free radicals generated by cell-free systems. We also identified active compound that is putatively responsible for free radical scavenging by analyzing NMR spectra. PHCR samples exhibited a concentration-dependent radical scavenging activity against hydroxyl radicals, superoxide anions, and DPPH radicals. Of the samples tested, a methanol-eluted sub-fraction from the PHCR extract, named $FF_4$, scavenged these radicals more effectively than the other fractions. We identified catechin-7-O-$\beta$-Dglucopyranoside as the active compound responsible for free radical scavenging potential of $FF_4$.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.263.2-263.2
• /
• 2003

There is now increasing evidence that free radicals and active oxygen species are involved in a variety of pathological events. Free radical-mediated cell damage and free radical attack on polyunsaturated fatty acids result in the formation of lipid radicals. These lipid radicals react readily with molecular oxygen to produce peroxy radicals responsible for initiating lipid peroxidation. The peroxidation of cellular membrane lipid can lead to cell necrosis and considered to ve implicated in a number of pathophysiological conditions including liver disease. (omitted)

• The Korean Journal of Food And Nutrition
• /
• v.29 no.6
• /
• pp.829-834
• /
• 2016

Free radicals originate due to the radiolysis of cytoplasmic water with low "Linear Energy Transfer" (LET) radiations. Naringenin (Ng) is a natural antioxidative compound found in citrus fruits. This study revealed that Naringenin (Ng) reduced the radiation damage of critical organs by scavenging oxidative free radicals. In the study, Ng was orally administrated to rats daily for 7 consecutive days, prior to whole body exposure to gamma-rays. The scavenging efficacy was evaluated biochemically by measuring the concentration of cytotoxic byproducts and the activity of enzymes relevant to oxidative free radicals, after extracting the organs from the exposed rat. We observed increased levels of malondialdehyde (MDA) concentration, and decrease in the activities of superoxide dismutase (SOD) and catalase (CAT) in the exposed control group. However, pretreatment with Ng significantly reduced the MDA concentration, and increased the activities of SOD and CAT, as compared to the control group, due to the free radical scavenging by Ng. The results indicate that Ng administration prior to irradiation could protect critical organs from radiation damage.

• Journal of Ginseng Research
• /
• v.32 no.2
• /
• pp.150-154
• /
• 2008

Twenty five albino rats were divided into five groups for conducting this experiment. The first group was for positive control (Vitamin C, ascorbic acid), the second group was of Panax ginseng (10 mg/kg body weight) treated group after bio-activity assay, the third group was of mercuric chloride treated group (0.033 mg/kg body weight) based on calculating $LD_{50}$ 9.26 mg/kg body weight by probit analysis, the fourth group was of mercuric chloride (0.033 mg/kg body weight) followed by Panax ginseng (10 mg/kg body weight) and the fifth group was Panax ginseng (10 mg/kg body weight) followed by mercuric chloride (0.033 mg/kg body weight) treated group. The interval between intake of Panax ginseng and mercuric chloride was of 2 hours in groups, fourth and fifth respectively. Comparative free radical scavenging property of Panax ginseng was studied under three in vitro models (role model for calculating scavenging activity) viz. DPPH method (hydroxyl free radicals), Nitric oxide method (nitrile free radicals) and Lipid peroxidation (mercury free radicals).