ABSTRACT
ABSTRACT PURPOSE: To evaluate the effect of Otostegia persica (O. persica) extract on renal damage induced by ischemia/reperfusion (I/R) in diabetic rats. METHODS: Forty-eight rats were subjected to right nephrectomy; then, they were allocated into six groups: Sham; Diabetic sham; I/R; Diabetic I/R; I/R+O. persica; Diabetic I/R+O. persica. Diabetes was induced by streptozotocin (200 mg/kg, i.p.). O. persica (300 mg/kg/day, p.o) was administered for 2 weeks. On the 15th day, ischemia was induced in left kidney for 60 min, followed by reperfusion for 24h. Renal functional and biochemical markers were estimated. RESULTS: I/R in both normal and diabetic rats, induced a significant elevation in serum levels of urea and creatinine (p<0.05). Renal I/R induced a significant increase of malondialdehyde, myeloperoxidase and nitric oxide concentrations associated with significant reduction in superoxide dismutase and catalase activities in comparison with the sham group (p<0.05). Diabetic rats that underwent renal I/R exhibited a significant increase in all the studied parameters with a reduction in the antioxidant enzymes as compared to nondiabetic rats (p<0.05). These deleterious effects associated with renal I/R were improved by the treatment with O. persica (p<0.05). CONCLUSION: Otostegia persica pretreatment protected the renal injury from ischemia-reperfusion in diabetic rats.
Subject(s)
Animals , Male , Plant Extracts/pharmacology , Reperfusion Injury/complications , Lamiaceae , Diabetes Mellitus, Experimental/complications , Antioxidants/pharmacology , Superoxide Dismutase/metabolism , Urea/blood , Blood Glucose/drug effects , Reperfusion Injury/metabolism , Catalase/metabolism , Rats, Wistar , Peroxidase/metabolism , Oxidative Stress/drug effects , Creatinine/blood , Models, Animal , Hypoglycemic Agents/pharmacology , Kidney/drug effects , Lipid Peroxides/metabolism , Nephrectomy/adverse effectsABSTRACT
Cadmium (Cd), is an environmental and industrial pollutant that affects the male reproductive system. Cd induces its effect by affecting tissue antioxidant enzyme systems. Green tea extract (GTE) is an antioxidant and free radicals scavenger and has a chelating property. The purpose of this study was to investigate the protective effect of GTE against testes damage induced by Cd. Four groups of male rats, were utilized as following: Controls, GTE treated, Cd treated and Cd + GTE, treated rats at the same doses. The rats received GTE and or Cd orally in drinking water. After 5 weeks, the animals were sacrificed and testes were removed for microscopic and Biochemical evaluation. The levels of lipid peroxides (LPO) and glutathione (GSH) were detected in the tissue homogenates of rat testes. The current study showed marked morphological changes in the form of swelling, congestion, hemorrhage and necrosis in testes of rats treated with Cd alone. However, the rats treated with Cd+GTE showed milder edema, congestion and minute foci of necrosis in the testes. The LPO levels were significantly higher as compared to control and of GSH were significantly lower in Cd-treated rats but when GTE was co-administrated with Cd, there was an effective reduction in oxidative stress as shown by a significant rise of GSH level. In conclusion, the rats received GTE + Cd could enhance antioxidant/ detoxification system which consequently reduced the oxidative stress in rat testes. The beneficial effect of GTE is thus potentially reducing Cd toxicity and tissue damage.
El cadmio (Cd), es un contaminante del medio ambiente e industrial que afecta al sistema reproductivo masculino. Cd induce su efecto por afección de los sistemas enzimáticos antioxidantes de los tejidos. El extracto de té verde (ETV) es un antioxidante y buscador de radicales libres y tiene una propiedad quelante. El objetivo de este estudio fue investigar el efecto protector de ETV contra daños provocado por Cd a los testículos. Cuatro grupos de ratas macho, se utilizaron: Controles, tratados con ETV, tratados con Cd y tratados con Cd + ETV, todas las ratas tratadas con las mismas dosis. Las ratas recibieron ETV o Cd por vía oral en el agua potable. Después de 5 semanas, los animales fueron sacrificados y los testículos fueron retirados para la evaluación microscópica y bioquímica. Los niveles de peróxidos lípidos (LPO) y de glutation (GSH) fueron detectados en el tejido homogenizado de rata testículos. El estudio demostró marcados cambios morfológicos como inflamación, congestión, hemorragia y necrosis en los testículos de las ratas tratadas solamente con Cd. Sin embargo, las ratas tratadas con Cd + ETV mostraron leves signos de edema, congestión y focos de necrosis en los testículos. Los niveles de LPO fueron significativamente mayores en comparación con el control y la de GSH fue significativamente menor en las ratas tratadas con Cd, pero cuando ETV fue co-administrado con Cd, hubo una reducción efectiva en el estrés oxidativo, como lo demuestra el aumento significativo del nivel de GSH. En conclusión, las ratas recibieron GTE + Cd que podría aumentar el sistema antioxidante / desintoxicación, por tanto, reducir el estrés oxidativo en los testículos de ratas. El efecto beneficioso de GTE es reducir la toxicidad y el daño tisular causado Cd.
Subject(s)
Animals , Male , Rats , Cadmium/toxicity , Oxidative Stress , Plant Extracts/pharmacology , Tea , Testis , Testis/pathology , Antioxidants/pharmacology , Glutathione/metabolism , Lipid Peroxides/metabolism , Rats, Sprague-DawleyABSTRACT
In the present study, the antioxidant capacity of vitamin C was examined in the liver and the kidney tissues of mice with or without ciprofloxacin (CFX) treatment. The antioxidant capacity of the vitamin was evaluated in terms of lipid hydroperoxides (LOOH) and thiobarbituric acid reactive substances (TBARs). The experimental design was 15 days of water (control and CFX groups) or vitamin C (vitamin C and vitamin C plus CFX groups) in drinking water. One dose of CFX was injected, 15 minutes before sacrifice, in the corresponding mice. The initial nmol of lipid hydroperoxides/g of tissue were 137 +/- 11 in the kidney and 145 +/- 15 in the liver, and the nmol of TBARs were 13 +/- 0.7 and 12 +/- 0.6, respectively.Pre-treatment with vitamin C reduced the levels of LOOH in the liver to 45 +/- 11 (p < 0.01) and vitamin C with CFX injection to 54 +/- 9 (p < 0.01). Vitamin C treatment also reduced the LOOH levels in the kidney roughly duplicated by CFX. Through the TBARs method we have not observed these effects. Quantification of LOOH is more sensitive than that of TBARs for estimating lipid peroxidation. CFX is used especially for urinary infections and can produce oxidative stress in the kidney. Pre-treatment with vitamin C may ameliorate this stress and also may improve the oxidative balance in the liver.
Subject(s)
Male , Rats , Animals , Female , Ascorbic Acid/pharmacology , Antioxidants/pharmacology , Ciprofloxacin/pharmacology , Liver , Liver/metabolism , Kidney , Kidney/metabolism , Diet , Mice, Inbred BALB C , Lipid Peroxidation , Lipid Peroxides/metabolism , Thiobarbituric Acid Reactive Substances/metabolismABSTRACT
The present investigation was carried out to study the induction of oxidative stress subjected to heavy metal environment. Lipoperoxides showed positive correlation at heavy metal accumulation sites indicating the tissue damage resulting from the reactive oxygen species and resulted in unbalance to cellular redox status. The high activities of ascorbate peroxidase and superoxide dismutase probably counter balance this oxidative stress. Glutathione and soluble phenols decreased, whereas dehydroascorbate content increased in the algae from polluted sites. The results suggested that alga responded to heavy metals effectively by antioxidant compounds and scavenging enzymes.
Subject(s)
Chlorophyta/drug effects , Antioxidants/metabolism , Lipid Peroxides/metabolism , Metals, Heavy/toxicity , Oxidative Stress/drug effects , Water Pollutants, Chemical/toxicityABSTRACT
Natural dietary ingredients are known for their antioxidant activity. Of such, curcumin, the active principle of turmeric, at 0.01% in the diet proved as pro-oxidative in galactose-induced cataract in vivo. The purpose of this study was to investigate the effect of vitamin E (VE), a well-known antioxidant, in combination with curcumin on the onset and maturation of galactose induced cataract. Periodic slit-lamp microscope examination indicated that in combination with vitamin-E, 0.01% curcumin (G-IV) delayed the onset and maturation of galactose-induced cataract. Biochemical analyses revealed that combined treatment of 0.01% curcumin and vitamin-E diet exhibited an efficient antioxidant effect, as it inhibited lipid peroxidation and contributed to a distinct rise in reduced glutathione content. The results indicate that natural dietary ingredients are effective in combination rather than the individual administration as they are complementing each other in reducing the risk of galactose induced cataract.
Subject(s)
Animals , Antioxidants/administration & dosage , Cataract/chemically induced , Curcumin/administration & dosage , Disease Models, Animal , Drug Synergism , Drug Therapy, Combination , Galactose , Glutathione/metabolism , Glutathione Reductase/metabolism , Lens, Crystalline/drug effects , Lipid Peroxides/metabolism , Male , Oxidative Stress/drug effects , Rats , Rats, Wistar , Superoxide Dismutase/metabolism , Vitamin E/administration & dosageABSTRACT
The objective of this study was to evaluate the protective immunity of excretory-secretory products of Fasciola hepatica (FhES) worm against S.mansoni infection in mice. Evaluation of FhES antigen was through measuring worm burden, ova count, granuloma size and frequency as well as the histopathological picture of the liver. The study was extended to determine the level of free radical scavengers; lipid peroxide, glutathione (GSH), vitamin C, vitamin E, catalase and superoxide dismutase (SOD). Liver function enzymes such as aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were also taken into consideration. Four groups of eight mice each were selected for this study. Group 1 served as control group. Group 2: normal healthy mice vaccinated with FhES product. Group 3: S.mansoni infected mice for 2 months and group 4: infected mice pre-vaccinated with FhES antigen. Vaccination schedule comprised of a single subcutaneous injection of FhES antigen emulsified with Freund's complete adjuvant in a dose 0.5 mg protein/mouse, followed by intraperitoneal injections of the same antigen without adjuvant in 3 doses/week for 3 successive weeks. The total antigen inoculation was 5 mg protein/mouse. The present results revealed a drastic change in all the measured parameters after S.mansoni infection and a noticeable improved level after vaccination with FhES antigen. It can be concluded that FhES antigen succeeded to protect mice against schistosomiasis by a significant reduction in worm burden, ova count, granuloma size and number, improvement in the histopathological architecture of the liver as well as amelioration in the antioxidant levels under investigation.
Subject(s)
Animals , Antigens, Helminth/immunology , Antioxidants/metabolism , Fasciola hepatica/immunology , Lipid Peroxides/metabolism , Liver/drug effects , Liver Function Tests , Male , Mice , Parasite Egg Count , Schistosomiasis mansoni/immunology , VaccinationABSTRACT
Introducción: En modelos experimentales, la formación de especies reactivas del oxígeno durante la reperfusión posisquémica induce ôestrés oxidativoõ que afecta al miocardio. Dado que los pacientes sometidos a cardioplejía sufren isquemia-reperfusión, se sugirió que en ellos habría estrés oxidativo. Sin embargo, este fenómeno aún no se ha caracterizado correctamente. Objetivo: El propósito del presente trabajo fue correlacionar la liberación de glutatión (el paso inicial de estrés oxidativo) con marcadores de progresión del daño oxidativo, como peroxidación de lípidos de membrana y desarrollo de alteraciones ultraestructurales. Material y métodos: En 24 pacientes sometidos a cirugía de puente aortocoronario se investigaron cambios en varios marcadores de estrés oxidativo y daño tisular durante la reperfusión posisquémica. Se obtuvieron muestras de sangre y biopsias cardíacas basales y luego de la reperfusión a 40,9 ± 11,9 minutos de la cardioplejía. La liberación de glutatión basal fue insignificante (0,02 ± 0,04 µmol/L), pero aumentó a los 15 minutos de la reperfusión (1,10 ± 0,40 µmol/L; p < 0,05); también disminuyeron los niveles tisulares de ubiquinol, de 144,5 ± 52 a 97,6 ± 82 nmol/g (p < 0,05). Aunque estos cambios documentan el estrés oxidativo cardíaco, no hubo alteraciones bioquímicas indicativas de daño celular, ya que no se produjo un incremento de marcadores de peroxidación lipídica, tanto en sangre del seno coronario como en las biopsias cardíacas. Tampoco se observaron alteraciones ultraestructurales importantes. Conclusiones: A pesar de observarse estrés oxidativo en pacientes sometidos a cirugía cardíaca, en las condiciones descriptas, no induce lesiones progresivas de membranas ni daño celular irreversible.
Subject(s)
Humans , Coronary Artery Bypass , Myocardial Ischemia , Myocardial Reperfusion Injury , Oxidative Stress , Lipid Peroxides/metabolism , Free Radicals , Myocardium/metabolism , OxygenABSTRACT
An experiment was conducted in rabbits to evaluate the possible involvement of oxidative stress in iron-overload animals. Ten adult female New Zealand white rabbits were divided into 2 equal groups with 5 animals each. Group II animals received intramuscular iron dextran injections (120 mg/kg body wt/day) on alternate day for 14 days (8 injections), while Group I animals did not receive any iron supplementation to serve as negative controls. The blood samples were collected by cardiac puncture before the start of iron dosing and thereafter, at weekly intervals for 28 days. The samples were processed to measure blood iron concentration, packed cell volume, erythrocytic lipid peroxide (LPO) level, superoxide dismutase (SOD) and catalase (CAT) activities. The blood iron concentration showed a rising trend following repeated iron administration, and the mean level recorded on day 14 was significantly higher than respective day 0 value. LPO level remained significantly higher from day 14 onwards till the end of the observation period of 14 more days after cessation of iron adminstration. Erythrocytic superoxide dismutase activities showed a transient significant rise on day 7, and thereafter, showed a declining trend, but remained statistically comparable to respective day 0 or corresponding value of the control animals.
Subject(s)
Animals , Antioxidants/metabolism , Catalase/metabolism , Erythrocytes/metabolism , Female , Glutathione Peroxidase/metabolism , Iron/metabolism , Lipid Peroxidation , Lipid Peroxides/metabolism , Oxidative Stress , Rabbits , Superoxide Dismutase/metabolism , Time FactorsABSTRACT
t-BHP induced oxidative stress and Ca2+ function impairment in fresh hepatocytes was studied in order to understand its role in cytotoxicity. Viability of hepatocytes by the release of lactate dehydrogenase and methyl thiazoletetrazolium reduction method alongwith malondialdehyde formation indicated oxidative stress in the hepatotoxic action of t-BHP.
Subject(s)
Animals , Antioxidants/pharmacology , Cell Survival/drug effects , Cells, Cultured , Hepatocytes/drug effects , Lipid Peroxides/metabolism , Male , Malondialdehyde/metabolism , Rats , Rats, Wistar , tert-Butylhydroperoxide/toxicityABSTRACT
The effect of Kraft black liquor on the lipid peroxidation of rat homogenates was examined. The lipid peroxidation of homogenates from different organs (kidney, brain, lung, and liver) was induced by Fenton's reagent. The products of lipid peroxidation, lipid hydroperoxides and TBARS were measured by FOX method and TBA assay, respectively. It was found that black liquor significantly reduced the concentration of TBARS, but not the concentration of lipid hydroperoxides. This inhibition was directly proportional to the concentration of Kraft black liquor and the incubation temperature. Conclusively, the black liquor from pulp and paper industry exhibited an antioxidant activity.
Subject(s)
Analysis of Variance , Animals , Antioxidants/chemistry , Hydrogen Peroxide , Iron , Lignin/chemistry , Lipid Peroxidation/drug effects , Lipid Peroxides/metabolism , Paper , Rats , Temperature , Thiobarbituric Acid Reactive Substances/metabolism , Tissue Extracts/metabolism , Waste ProductsABSTRACT
Ascorbic acid treatment significantly increased the activities of testicular delta5, 3beta-HSD and 17beta-HSD. Moreover, the treatment was also associated with significant decrease in oxidative stress in the testis. Ethanol induced oxidative stress and decreased steroidogenesis can be reversed by treatment with ascorbic acid.
Subject(s)
Administration, Oral , Animals , Antioxidants/therapeutic use , Ascorbic Acid/therapeutic use , Body Weight/drug effects , Ethanol/toxicity , Glutathione/metabolism , Gonadal Steroid Hormones/biosynthesis , Lipid Peroxides/metabolism , Male , Oxidative Stress/drug effects , Rats , Testis/drug effectsABSTRACT
Diabetes induced by streptozotocin (50 mg/kg body wt, i.p.) in the rats substantially increased the plasma glucose and malondialdehyde levels along with corresponding decrease in the antioxidants levels. Supplementation of vitamin E (200 mg/kg body wt., ip) for 5 weeks resulted in non-significant decrease in the blood glucose levels but plasma malondialdehyde levels were reduced to below normal levels. Plasma vitamin E, vitamin C, uric acid and red blood cell glutathione levels were also restored to near normal levels on vitamin E supplementation to diabetic rats as compared to control (diabetic) rats. The activities of antioxidant enzymes, catalase (EC 1.11.1.6), glutathione peroxidase (GSHPx EC 1.11.1.9), and glutathione reductase (GR EC 1.6.4.2) were also concomitantly restored to near normal levels by vitamin E supplementation to diabetic rats. The results clearly demonstrated that vitamin E supplementation augments the antioxidant defense mechanism in diabetes and provides evidence that vitamin E may have a therapeutic role in free radical mediated diseases.
Subject(s)
Animals , Antioxidants/administration & dosage , Ascorbic Acid/blood , Catalase/metabolism , Diabetes Mellitus, Experimental/blood , Erythrocytes/metabolism , Glutathione/blood , Glutathione Peroxidase/metabolism , Glutathione Reductase/metabolism , Lipid Peroxides/metabolism , Liver/drug effects , Male , Oxidative Stress/drug effects , Rats , Rats, Wistar , Uric Acid/blood , Vitamin E/administration & dosageABSTRACT
Culture filtrate of Lasiodiplodia theobromae increased respiration rate, phenylalanine ammonia lyase activity, and levels of hydrogen peroxide, lipid peroxides and salicylic acid in B. nigra plants. Salicylic acid (SA) level increased for 1 hr of interaction and reduced later. Development of systemic acquired resistance (SAR) was found restricted in plants infected with L. theobromae due to deficiency of SA, which is a major signal for development of SAR. Exogenously supplied SA did develop resistance and plant death was delayed. It was hypothesized that deficiency of SA could be due to jasmonic acid produced by fungus that inhibits SA biosynthesis.
Subject(s)
Ascomycota/metabolism , Ascorbic Acid/metabolism , Chromatography, High Pressure Liquid , Cyclopentanes/metabolism , Hydrogen Peroxide/metabolism , Immunity, Innate , Lipid Peroxides/metabolism , Mustard Plant/microbiology , Mycotoxins/metabolism , Oxylipins , Reactive Oxygen Species , Salicylic Acid/metabolism , Time FactorsABSTRACT
Accurate estimation of the exposure-response relationship between ambient urban particulate matters (PM) and public health is important for regulatory perspective of ambient urban particulate matters (PM). Ambient PM contains various transition metals and organic compounds. PM10 (aerodynamic diameter less than 10 microgram) is known to induce diverse diseases such as chronic cough, bronchitis, chest illness, etc. However, recent evaluation of PM2.5 (aerodynamic diameter less than 2.5 microgram) against health outcomes has suggested that the fine particles may be more closely associated with adverse respiratory health effects than particles of larger size. This study was performed to evaluate PM2.5-induced oxidative stress in rat lung epithelial cell in order to provide basic data for the risk assessment of PM2.5. PM2.5 showed higher cytotoxicity than PM10. Also, PM 2.5 induced more malondialdehyde (MDA) formation than PM10. In Hoechst 33258 dye staining and DNA fragmentation assay, apopotic changes were clearly detected in PM2.5 treated cells in compared to PM10. Expression of catalase mRNA was increased by PM2.5 rather than PM10. PM2.5 induced higher Mth1 mRNA than PM10. In pBR322 DNA treated with PM2.5, production of single strand breakage of DNA was higher than that of PM10. In Western blot analysis, PM2.5 induced more Nrf-2 protein, associated with diverse transcriptional and anti-oxidative stress enzymes, compared to PM10. Our data suggest that PM2.5 rather than PM10 may be responsible for PM-induced toxicity. Additional efforts are needed to establish the environmental standard of PM2.5.
Subject(s)
Animals , Rats , Air Pollutants/chemistry , Apoptosis/physiology , Benzimidazoles/metabolism , Blotting, Western , Cell Line , Cell Survival/physiology , DNA Fragmentation/physiology , DNA Repair Enzymes/genetics , DNA-Binding Proteins/metabolism , Epithelial Cells/drug effects , Formazans/metabolism , GA-Binding Protein Transcription Factor , Lipid Peroxides/metabolism , Lung Diseases/chemically induced , Oxidative Stress/physiology , RNA, Messenger/chemistry , Reverse Transcriptase Polymerase Chain Reaction , Tetrazolium Salts/metabolism , Transcription Factors/metabolismABSTRACT
Rats fed excess vitamin A showed decreased body weight gain and protein efficiency ratio. In rats fed low protein vitamin A level increased in liver but with an associated decrease in plasma. These changes were reversed in high protein fed state. The amount of protein in diet had little effect on haemoglobin level in erythrocyte, but excess vitamin A in diet significantly decreased haemoglobin level in erythrocyte. Lipid peroxidation (LP) increased in rats fed low protein and decreased in high protein fed rats. Rats fed high protein and excess vitamin A showed minimum level of LP. Result showed that high protein in diet increased the levels of antioxidant enzymes, catalase and superoxide dismutase (SOD) and that excess vitamin A supplementation functions synergistically with high protein in diet to increase antioxidant enzymes level.
Subject(s)
Animals , Catalase/metabolism , Dietary Proteins/administration & dosage , Erythrocytes/metabolism , Glutathione Peroxidase/metabolism , Hemoglobins/analysis , Hypervitaminosis A/metabolism , Lipid Peroxidation , Lipid Peroxides/metabolism , Liver/drug effects , Male , Oxidoreductases/metabolism , Protein Deficiency , Rats , Rats, Wistar , Superoxide Dismutase/metabolism , Vitamin A/bloodABSTRACT
Fructose-fed rats were more susceptible to peroxidative damage as measured by thiobarbituric acid reactive species. The concentrations of lipid peroxides, diene conjugates, lipofuscin and hydroperoxides were significantly higher. The levels of enzymic antioxidants such as vitamin C, vitamin E and glutathione and activities of antioxidant enzymes were significantly lower in fructose-fed rats. When these rats received taurine in drinking water, peroxidative damage was minimal in both plasma and liver. Taurine was effective in inducing the antioxidant potential in fructose-fed rats. Increased peroxidative damage in liver is likely to be associated with fructose dependent pathology, which could be reduced by taurine by enhancing the antioxidant potential.
Subject(s)
Animals , Antioxidants/metabolism , Ascorbic Acid/blood , Catalase/metabolism , Diet , Fructose/administration & dosage , Glutathione/blood , Glutathione Peroxidase/metabolism , Glutathione Reductase/metabolism , Hydrogen Peroxide/metabolism , Lipid Peroxides/metabolism , Lipofuscin/metabolism , Liver/drug effects , Male , Rats , Rats, Wistar , Superoxide Dismutase/metabolism , Taurine/administration & dosage , Thiobarbituric Acid Reactive Substances/metabolism , Vitamin E/bloodABSTRACT
Maize (Zea mays L. cv kanaujia) plants grown with Zn [10 (control), 0.1 (low) and 20 microM (high)], were investigated for concentration of antioxidants and activities of antioxidative enzymes in leaves. Young leaves of low Zn plants developed whitish-necrotic spots. Leaves of both low and high Zn plants showed decrease in chlorophyll concentration and accumulation of lipid peroxides, ascorbate and dehydroascorbate, associated with a decrease in the activity of ascorbate peroxidase and superoxide dismutase. Low and high Zn, however, showed diverse effect on glutathione reductase. While low Zn increased the activity of glutathione reductase, high Zn decreased its activity. Zinc effect on antioxidative constituents suggested Zn involvement in sustaining the antioxidative defense system in maize leaves.
Subject(s)
Antioxidants/metabolism , Ascorbic Acid/metabolism , Chlorophyll/metabolism , Dehydroascorbic Acid/metabolism , Glutathione Reductase/metabolism , Lipid Peroxides/metabolism , Necrosis , Peroxidases/metabolism , Plant Leaves/enzymology , Superoxide Dismutase/metabolism , Zea mays/drug effects , Zinc/pharmacologyABSTRACT
Short-term feeding studies were carried out to investigate the effect of ingestion of salted dried fish on alterations in tissue lipid peroxidation and modulation of the activities of detoxification enzymes in liver in order to study the induction of oxidative stress. Rats were fed diets with either 5, 10 and 20% dried mackerel for 4 weeks and levels of antioxidants in liver were estimated. The results showed that the fish intake at 10 and 20% dietary level reduced glutathione with a reciprocal increase in thiobarbituric acid reactive substances and a concomitant decrease in antioxidant vitamins A and C contents in liver. A significant decline in the activities of hepatic glutathione peroxidase and glutathione reductase were also observed at these levels of fish consumption. Kidney gamma-glutamyl transpeptidase activity on the other hand was increased abnormally at 20% fish intake. The results suggested that the dried fish consumption at higher concentrations (at 10 and 20%) for a short period caused lowering of the activities of antioxidative enzymes thereby inducing oxidative stress in rat liver.