The Protection of Lactic Acid Bacteria Fermented-Mango Peel against Neuronal Damage Induced by Amyloid-Beta.

Mango peels are usually discarded as waste; however, they contain phytochemicals and could provide functional properties to food and promote human health. This study aimed to determine the optimal lactic acid bacteria for fermentation of mango peel and evaluate the effect of mango peel on neuronal protection in Neuron-2A cells against amyloid beta (Aß) treatment (50 µM). Mango peel can be fermented by different lactic acid bacteria species. Lactobacillus acidophilus (BCRC14079)-fermented mango peel produced the highest concentration of lactic acid bacteria (exceeding 108 CFU/mL). Mango peel and fermented mango peel extracts upregulated brain-derived neurotrophic factor (BDNF) expression for 1.74-fold in Neuron-2A cells. Furthermore, mango peel fermented products attenuated oxidative stress in Aß-treated neural cells by 27%. Extracts of L. acidophilus (BCRC14079)-fermented mango peel treatment decreased Aß accumulation and attenuated the increase of subG1 caused by Aß induction in Neuron-2A cells. In conclusion, L. acidophilus (BCRC14079)-fermented mango peel acts as a novel neuronal protective product by inhibiting oxidative stress and increasing BDNF expression in neural cells.

Inhibition of aqueous extracts of Solanum nigrum (AESN) on oral cancer through regulation of mitochondrial fission.

The present study is designed to investigate the anti-oral cancer properties of Solanum nigrum on oral squamous cell carcinoma. S. nigrum is a Chinese herb used for suppression of various cancers. However, the inhibition of S. nigrum on oral cancer is unclear. Therefore, human oral squamous cancer cells (SCC)-4 were used to evaluate the effect of aqueous extracts of S. nigrum (AESN) on cancer cell proliferation, cell cycle, mitochondrial function and apoptosis. The SCC-4 cells were treated by AESN to evaluate the inhibition of cell proliferation and mitochondrial function in vitro. Our results suggested that AESN markedly increased reactive oxygen species production. AESN also promoted caspase-9 and caspase-3 activation and subsequent triggering of the mitochondrial apoptotic pathway. The inhibition of glucose uptake was alleviated mediated by a dose-dependent manner in SCC-4 cells with AESN treatment for 24 h, resulting in mitochondrial fission. These results suggested that AESN has potential to be used as a functional food in adjuvant chemotherapy for treating human oral cancer by suppression of mitochondrial function.

Miracle Fruit (Synsepalum dulcificum) Exhibits as a Novel Anti-Hyperuricaemia Agent.

Miracle fruit (Synsepalum dulcificum) belongs to the Sapotaceae family. It can change flavors on taste buds, transforming acidic tastes to sweet. We evaluated various miracle fruit extracts, including water, butanol, ethyl acetate (EA), and hexane fractions, to determine its antioxidant effects. These extracts isolated from miracle fruit exerted potential for reduction of uric acid and inhibited xanthine oxidase activity in vitro and in monosodiumurate (MSU)-treated RAW264.7 macrophages. Moreover, we also found that the butanol extracts of miracle fruit attenuated oxonic acid potassium salt-induced hyperuricaemia in ICR mice by lowering serum uric acid levels and activating hepatic xanthine oxidase. These effects were equal to those of allopurinol, suggesting that the butanol extract of miracle fruit could be developed as a novel anti-hyperuricaemia agent or health food.

Actinidia callosa peel (kiwi fruit) ethanol extracts protected neural cells apoptosis induced by methylglyoxal through Nrf2 activation.

CONTEXT: Methylglyoxal (MG) is a reactive dicarbonyl compound generated as an intermediate of glycolysis during the physical glycation in the diabetic condition. MG itself has been commonly implicated in the development of diabetic neuropathy. Several active compounds in Actinidia callosa have been found to inhibit glycation and MG-protein reaction. OBJECTIVE: This study investigated the protective effects of A. callosa (kiwi fruits) peel ethanol extracts (ACE) on MG-induced Neuro-2A cell apoptosis. MATERIALS AND METHODS: The Neuro-2A cells pre-treated by ACE (50-200 µg/mL) or allyl-isothiocyanate (AITC) (50 µM) for 6 h, in turn, the cells were treated with MG (250 µM) for 24 h. RESULTS: ACE or AITC treatment markedly inhibited the generation of reactive oxygen species (ROS) and the elevation of caspase-3 and capase-9 levels induced by MG in Neuro-2A cells. ACE and AITC elevated Bcl2 and inhibited Bax expressions in MG-induced Neuro-2A cells. ACE elevated Nrf2 transcriptional activity and nuclear translocation in MG-induced Neuro-2A cells. Nrf2 down-stream molecules including HO-1 and GCL were elevated by ACE or AITC treatment in MG-induced Neuro-2A cells. The protective effects of ACE on MG-induced Neuro-2A apoptosis were attenuated while Nrf2 knockdown. DISCUSSION AND CONCLUSION: We established the first evidence that ACE might contribute to the prevention of the development of diabetic neuropathy by blocking the MG-mediated intracellular glycation system.

Ice plant (Mesembryanthemum crystallinum) improves hyperglycaemia and memory impairments in a Wistar rat model of streptozotocin-induced diabetes.

BACKGROUND: Ice plant (Mesembryanthemum crystallinum) has been used as an anti-diabetic agent in Japan because it contains d-pinitol. The efficacy of ice plant in the regulation of blood glucose is unclear at present. Recently, memory impairment and development of Alzheimer's disease found in diabetic patients are thought to be caused by high blood glucose. The mechanism by which ice plant protects against the impairment of memory and learning abilities caused by high blood glucose remains unclear. The aim of this study was to evaluate the protection of ice plant water extracts (IPE) and D-pinitol against memory impairments in a Wistar rat model of streptozotocin (STZ)-induced diabetes. We hypothesised that IPE and D-pinitol could suppress blood glucose and elevate insulin sensitivity in these rats. RESULTS: For memory evaluation, IPE and D-pinitol also improved the passive avoidance task and the working memory task. In addition, inhibition of acetylcholinesterase activity in hippocampus and cortex was found in this rat model administered IPE or D-pinitol. IPE and D-pinitol also markedly elevated superoxide dismutase activity against oxidative stress and reduced malondialdehyde production in hippocampus and cortex of the rats. CONCLUSION: These findings indicated that IPE and D-pinitol possess beneficial effects for neural protection and memory ability in a rat model of diabetes.

Graptopetalum paraguayense and resveratrol ameliorates carboxymethyllysine (CML)-induced pancreas dysfunction and hyperglycemia.

Hyperglycemia is associated with advanced glycation end products (AGEs). Recently, AGEs were found to cause pancreatic damage, oxidative stress, and hyperglycemia through the AGE receptor. Carboxymethyllysine (CML) is an AGE but whether it induces pancreatic dysfunction remains unclear. Graptopetalum paraguayense, a vegetable consumed in Taiwan, has been used in folk medicine and is an antioxidant that protects against liver damage. We investigated the protective properties of G. paraguayense 95% ethanol extracts (GPEs) against CML-induced pancreatic damage. The results indicated that resveratrol, GPE, and gallic acid (the active compound of GPE) increased insulin synthesis via upregulation of pancreatic peroxisome proliferator activated-receptor-γ (PPARγ) and pancreatic-duodenal homeobox-1 (PDX-1) but inhibited the expression of CML-mediated CCAAT/enhancer binding protein-ß (C/EBPß), a negative regulator of insulin production. Moreover, resveratrol and GPE also strongly activated nuclear factor-erythroid 2-related factor 2 (Nrf2) to attenuate oxidative stress and improve insulin sensitivity in the liver and muscle of CML-injected C57BL/6 mice and resulted in reduced blood glucose levels. Taken together, these findings suggested that GPE and gallic acid could potentially be used as a food supplement to protect against pancreatic damage and the development of diabetes.

Graptopetalum paraguayense Ameliorates Airway Inflammation and Allergy in Ovalbumin- (OVA-) Sensitized BALB/C Mice by Inhibiting Th2 Signal.

Role of inflammation-induced oxidative stress in the pathogenesis and progression of chronic inflammatory airways diseases has received increasing attention in recent years. Nuclear factor erythroid 2-related factor 2 is the primary transcription factor that regulates the expression of antioxidant and detoxifying enzymes. Graptopetalum paraguayense E. Walther, a vegetable consumed in Taiwan, has been used in folk medicine for protection against liver injury through elevating antioxidation. Recently, we found that gallic acid is an active compound of Graptopetalum paraguayense E. Walther, which has been reported to inhibit T-helper 2 cytokines. Currently, we assumed that Graptopetalum paraguayense E. Walther may potentially protect against ovalbumin-induced allergy and airway inflammation. Results demonstrated that Graptopetalum paraguayense E. Walther ethanolic extracts (GPE) clearly inhibited airway inflammation, mucus cell hyperplasia, and eosinophilia in OVA-challenged mice. Additionally, GPE also prevented T-cell infiltration and Th2 cytokines, including interleukin- (IL-)4, IL-5, and IL-13 generations in bronchial alveolar lavage fluid. The adhesion molecules ICAM-1 and VCAM-1 were substantially reduced by GPE treatment mediated by Nrf2 activation. Moreover, GPE attenuated GATA3 expression and inhibited Th2 signals of the T cells. These findings suggested that GPE ameliorated the development of airway inflammation through immune regulation.

Rutin and quercetin, bioactive compounds from tartary buckwheat, prevent liver inflammatory injury.

Tartary buckwheat (Fagopyrum tataricum) is a healthy and nutritionally important food item. In this study, we investigated the hepatoprotective effects of 75% ethanol extracts from tartary buckwheat (EEB) against ethanol- and carbon tetrachloride (CCl(4))-induced liver damage. EEB were administered to C57BL/6 mice (ethanol induction) and Sprague-Dawley (SD) rats (CCl(4) induction) for 4 and 8 consecutive weeks, respectively. The major active compounds, rutin and quercetin, were also administered to ethanol- and CCl(4)-induced animals. EEB inhibited increase in serum aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) levels in the ethanol- and CCl(4)-induced animals; similar effects were found after rutin and quercetin administration. Moreover, EEB elevated the antioxidant enzyme activities, including those of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD), and inhibited the levels of hepatic inflammation in the ethanol- and CCl(4)-treated animals. This study suggests that EEB exerts hepatoprotection via promoting anti-oxidative and anti-inflammatory properties against oxidative liver damage.

Antioxidant and anti-inflammatory effects of pigeon pea (Cajanus cajan L.) extracts on hydrogen peroxide- and lipopolysaccharide-treated RAW264.7 macrophages.

Chronic inflammation has been linked to a wide range of progressive diseases, including cancer, neurological disease, metabolic disorder, and cardiovascular disease. Epidemiological studies have provided convincing evidence that natural dietary compounds, which humans consume as food, possess many biological activities, including chemopreventative activities against various chronic inflammatory diseases. Here, we investigated the effect of 50% ethanol extracts of pigeon pea, as well as its major component, cyanidin-3-monoglucoside, an anthocyanin, on DNA damage, the activity of antioxidant enzymes, and free radical scavenging capacity in hydrogen peroxide (H(2)O(2))-treated RAW264.7 macrophages. High-pressure liquid chromatography results indicated that 2 mg of the 50% ethanol extracts of pigeon pea contained 45 µg of cyanidin-3-monoglucoside. A comet assay indicated that 50% ethanol extracts of pigeon pea (2 mg mL(-1)) and of cyanidin-3-monoglucoside (10 µM) protected RAW264.7 cells from DNA damage induced by a 24 h H(2)O(2) treatment. These results can be attributed to the prevention of reduction in antioxidant enzyme activity and lipid peroxidation in H(2)O(2)-treated murine RAW264.7 macrophages by the 50% ethanol extracts of pigeon pea. Moreover, as there is an active interplay between oxidative stress and inflammation, we also evaluated the anti-inflammatory activity of the 50% ethanol extracts of pigeon pea and cyanidin-3-monoglucoside in lipopolysaccharide-treated RAW264.7 macrophages. We found that the 50% ethanol extracts of pigeon pea and of cyanidin-3-monoglucoside suppressed the production of inflammatory cytokines, including TNF-α, IL-1ß, and IL-6, in these macrophages. These results imply that pigeon pea could be developed as a functional food by the food industry, or could be utilized for the commercial production of anthocyanins as antioxidants.

Fagopyrum tataricum (buckwheat) improved high-glucose-induced insulin resistance in mouse hepatocytes and diabetes in fructose-rich diet-induced mice.

Fagopyrum tataricum (buckwheat) is used for the treatment of type 2 diabetes mellitus in Taiwan. This study was to evaluate the antihyperglycemic and anti-insulin resistance effects of 75% ethanol extracts of buckwheat (EEB) in FL83B hepatocytes by high-glucose (33 mM) induction and in C57BL/6 mice by fructose-rich diet (FRD; 60%) induction. The active compounds of EEB (100 µg/mL; 50 mg/kg bw), quercetin (6 µg/mL; 3 mg/kg bw), and rutin (23 µg/mL; 11.5 mg/kg bw) were also employed to treat FL83B hepatocytes and animal. Results indicated that EEB, rutin, and quercetin + rutin significantly improved 2-NBDG uptake via promoting Akt phosphorylation and preventing PPARγ degradation caused by high-glucose induction for 48 h in FL83B hepatocytes. We also found that EEB could elevate hepatic antioxidant enzymes activities to attenuate insulin resistance as well as its antioxidation caused by rutin and quercetin. Finally, EEB also inhibited increases in blood glucose and insulin levels of C57BL/6 mice induced by FRD.

Hepatoprotection of emodin and Polygonum multiflorum against CCl(4)-induced liver injury.

CONTEXT: Polygonum multiflorum is known as a medicinal plant. It has been used as a folk medicine which showed antioxidative property. OBJECTIVE: Protective effects of the water extracts (w/v:1/10) from fresh P. multiflorum (WEP) on carbon tetrachloride (CCl(4))-induced liver damage in rats were investigated. MATERIALS AND METHODS: CCl(4) was used for inducing liver damage of SD rats, and WEP and emodin were fed for eight consecutive weeks. RESULTS: We found that emodin levels in fresh WEP was higher than that in ripening WEP. Rats were administered WEP and emodin, the main active compound, for 56 consecutive days. WEP significantly lowered the serum levels of hepatic enzyme markers, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and reduced the generation of malonaldehyde. Treatment with WEP recovered glutathione S-transferase and catalase activity in rats as compared to treatment with CCl(4) alone. In addition, serum tumor necrosis factor-α, an inflammatory marker, was found to decrease in rats treated with WEP. In histopathological evaluation, fatty degeneration and necrosis were found to be significantly decreased in the CCl(4) plus WEP treatment group. DISCUSSION AND CONCLUSION: WEP may be effective in attenuating liver damage by reducing lipid peroxidation as well as by positively modulating inflammation.

Influence of dietary supplementation with Bacillus-fermented adlay on lipid metabolism, antioxidant status and intestinal microflora in hamsters.

BACKGROUND: The effects of polished and dehulled Bacillus-fermented adlay on lipid metabolism, antioxidant status and intestinal microflora were examined in hyperlipidaemic hamsters fed a high-cholesterol diet. RESULTS: Hamsters administered Bacillus-fermented adlay experienced significantly reduced (P < 0.05) serum and hepatic total cholesterol (by 37-43% and 42-49% respectively) and triglyceride (by 22-27% and 30-35% respectively) levels compared with the high-cholesterol group. Lower low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratios in serum and increased cholesterol (by 47-52%) and triglyceride (by 40-47%) contents in faeces were also observed. Bacillus-fermented adlay lowered the levels of thiobarbituric acid-reactive substances, thus increasing total antioxidant and superoxide dismutase activities. In particular, polished Bacillus-fermented adlay had satisfactory antioxidant activity, similar to that of commercially available natto. Moreover, hamsters fed Bacillus-fermented adlay harboured greater populations of lactic acid bacteria, few coliforms and little Clostridium perfringens. CONCLUSION: This study has shown that changes in lipid metabolism, antioxidant status and intestinal microflora can be greatly modulated by Bacillus-fermented adlay, suggesting potential novel approaches to the treatment of primary cardiovascular and intestinal diseases.

Oral administration of Trapa taiwanensis Nakai fruit skin extracts conferring hepatoprotection from CCl4-caused injury.

As a folk medicine, the hot-water infusion of water caltrop fruits has been used to protect the liver. In this study, the outer skins of mature water caltrop fruits ( Trapa taiwanensis Nakai) were removed, forced-air-dried, pulverized, and subjected to extraction with hot water, and the infusion was lyophilized and pulverized to prepare a hot water extract of T. taiwanensis (HWETT). HWETT was subjected to assays of α,α-diphenyl-ß-picrylhydrazyl scavenging activity, reducing power, Trolox equivalent antioxidant capacity, and antioxidative potency, and all determinations showed HWETT to be a potent antioxidant. As further analyzed with LC-MS, two major HPLC-detected components were elucidated as gallic acid and ellagic acid. Hepatoprotective activity of HWETT was assessed with Sprague-Dawley male rats by oral administration. Six groups of rats (n = 8 for each) were respectively treated, namely, control, CCl(4) (20% CCl(4)/olive oil by 2.0 mL/kg bw), CCl(4) and Silymarin (200 mg/kg bw), CCl(4) and low HWETT dose (12.5 mg/kg bw), CCl(4) and medium HWETT dose (25 mg/kg bw), and CCl(4) and high HWETT dose (125 mg/kg bw). After 8 weeks, all animals were fasted for an additional day and sacrificed to collect blood, liver, and kidney for analyses. Histopathological examinations showed that oral administrations with Silymarin and HWETT were effective in protecting the liver from CCl(4)-caused fatty change. Oral administration of HWETT at 125 mg/kg bw was more effective than was Silymarin at 200 mg/kg bw. On biochemical analyses, oral administrations with HWETT at medium and high doses were effective (p < 0.05) in lowering CCl(4)-caused increases of alanine aminotransferase and aspartate aminotransferase activities. It is of merit to demonstrate HWETT as a potent source of antioxidants and hepatoprotective agents.

Hepatoprotection of Graptopetalum paraguayense E. Walther on CCl4-induced liver damage and inflammation.

AIM OF THIS STUDY: Graptopetalum paraguayense E. Walther, a vegetable consumed in Taiwan, has been used in folk medicine for protection against liver injury, although its actual efficacy remains uncertain. Therefore, we investigated the protective effects of Graptopetalum paraguayense E. Walther against carbon tetrachloride (CCl(4))-induced liver damage in rats. MATERIALS AND METHODS: Water extracts of Graptopetalum paraguayense E. Walther (WGP) were administered for 8 consecutive weeks to male Sprague-Dawley rats. And a dose-dependent manner in preventing liver damage was confirmed. Moreover, the major ingredient of WGP, gallic acid, was also orally administrated in the CCl(4)-induced rats. The hepatoprotective activity was assessed using various biochemical parameters such as antioxidant enzymes and histopathological studies. RESULTS: WGP ranging from 50 to 300 mg/kg bw administrations significantly lowered serum aspartate transaminase (AST) and alanine transaminase (ALT) levels, and inhibited malondialdehyde (MDA) generation in CCl(4)-treated rats. WGP increased cellular GSH level and antioxidant enzymes, including superoxide dismutase, glutathione reductase, and catalase. Serum tumor necrosis factor-alpha (TNF-α) was decreased in the group treated with CCl(4) plus WGP (150 and 300 mg/kg bw). Histopathological examination of livers showed that WGP reduced fatty degeneration, cytoplasmic vacuolization and necrosis in CCl(4)-treated rats. In contrary, 10mg/kg bw of gallic acid was administrated, this dose was related with WGP (300 mg/kg bw), and had significantly decreased the AST and ALT compared to the CCl(4)-treated group. Aforesaid results suggested that gallic acid from WGP offered antioxidative activity against CCl(4)-induced oxidative liver damage. CONCLUSIONS: Taken together, this study is the first time to suggest that Graptopetalum paraguayense E. Walther exerts hepatoprotection via promoting antioxidative and anti-inflammatory properties against CCl(4)-induced oxidative liver damage.

Buckwheat polysaccharide exerts antiproliferative effects in THP-1 human leukemia cells by inducing differentiation.

Buckwheat is a healthy food commonly eaten worldwide. The antitumor activity of buckwheat polysaccharides (BWPSs) has not yet been evaluated. In recent years, inducing differentiation of leukemic cells has become one of the most important therapeutic approaches for curing leukemia, and this strategy effectively inhibits leukemia cell proliferation and growth because the differentiation inducer changes leukemic cell morphology and cellular characters by inducing cellular maturity. The ability of BWPS to induce the differentiation of human leukemic THP-1 cells (monocyte [MNC]/macrophage-like cells) was investigated by both direct and indirect treatments in this study. In the indirect treatment, BWPS significantly stimulated cytokine secretion (differentiation inducer) in MNCs from peripheral blood mononuclear cells in MNC-conditioned medium (BWPS-MNC-CM) following a 24-hour treatment, and THP-1 cell differentiation and maturity were significantly increased after 5 days of treatment with the BWPS-MNC-CM. On the other hand, BWPS directly induced THP-1 cell differentiation and maturity following 3-day and 5-day treatments in a dose-dependent manner and exerted phagocytic activity and superoxide anion production in these mature cells. These findings indicate that BWPS has potential for differentiation therapy in leukemia.

Improvement of the hypocholesterolemic activities of two common fruit fibers by micronization processing.

This study investigated and compared the potential hypocholesterolemic activities of different insoluble fibers (IFs) prepared from carambola and orange pomace with or without micronization processing. After micronization, the cation-exchange and water-holding capacities of these pectic polysaccharide-rich IFs were effectively increased (from 140 to 180% and from 260 to 290%, respectively). The abilities of these microsized fruit IFs to lower the concentrations of serum triglyceride (by 15.6-17.8%) and serum total cholesterol (by 15.7-17.0%) were significantly (p < 0.05) improved, possibly by means of enhancing the excretion of cholesterol (123-126%) and bile acids (129-133%) in feces. Fecal moisture content was also increased (127-131%) by the consumption of microsized IFs. These results demonstrated that particle size is an important factor in affecting the characteristics and physiological functions of insoluble fibers. The approach of micronization processing might offer the industry an opportunity to improve the physiological functions of food fibers in fiber-rich functional food applications.

Genotoxicity and oxidative stress of the mutagenic compounds formed in fumes of heated soybean oil, sunflower oil and lard.

This study was to investigate the genotoxicity and cytotoxicity of the oil fumes formed from heating three common commercial cooking oils (soybean oil, sunflower oil, and lard) on human lung carcinoma pulmonary type II-like epithelium cell (A-549 cell). The major alkenal mutagenic compounds (trans-trans-2,4-decadienal, t-t-2,4-DDE; trans-trans-2,4-nonadienal, t-t-2,4-NDE; trans-2-decenal, t-2-DCA and trans-2-undecenal, t-2-UDA) contained in three oil fumes and their effects on the induction of reactive oxygen species (ROS) were also studied. It was found that the most potent mutagenic compound (t-t-2,4-DDE) of oil fumes was 66.4, 35.9 and 40.3 microg/g in soybean oil, sunflower oil and lard, respectively. The results indicated that the methanolic extracts of oil fumes could apparently lead to cytotoxicity and oxidative DNA damage. Glutathione (GSH) contents and the activities of antioxidant enzymes such as GSH reductase, and GSH S-transferase were adversely reduced by the methanolic extracts of oil fumes. When human A-549 cells were exposed to the methanolic extracts of oil fumes for 30 min, there was an increase in the formation of intracellular ROS, which was determined by dichlorofluorescein assay. Moreover, the methanolic extracts of oil fumes caused significant (p<0.05) oxidative damage through the 8-hydroxy-2'-deoxyguanosine formation in A-549 cells at the concentrations from 50 to 200 microg/ml. These results demonstrated that the DNA damage in A-549 cells, induced by cooking oil fumes, was related to the ROS formation. It is inferred that women exposed to emitted fumes from cooking oil were at higher risk of contracting lung cancer.

Effects of cooking oil fumes on the genotoxicity and oxidative stress in human lung carcinoma (A-549) cells.

This study investigates the genotoxicity and cytotoxicity of oil fumes, formed when peanut oil is heated, on human lung carcinoma pulmonary type II-like epithelium cells. The major mutagenic compound (trans-trans-2,4-decadienal, t-t-2,4-DDE) contained in oil fumes and its effect on the induction of reactive oxygen species (ROS) is also discussed. The results indicate that the methanolic extract of oil fumes can apparently lead to cytotoxicity and oxidative DNA damage. Glutathione (GSH) content, and the activities of antioxidative enzymes such as GSH reductase, GSH peroxidase and GSH S-transferase were adversely reduced by the methanolic extract of oil fumes. t-t-2,4-DDE could produce superoxide anion, hydrogen peroxide and hydroxyl radicals in a phosphate buffer (pH 7.4), and form intracellular ROS, determined by dichlorofluorescein assay in A-549 cells. Moreover, t-t-2,4-DDE caused significant (P <0.05) oxidative damage of the 8-hydroxy-2'-deoxyguanosine formation in A-549 cells at concentrations from 50 to 200 microM. These results demonstrated that the DNA damage in A-549 cells, induced by t-t-2,4-DDE, was related to the ROS formation. The occurrence of t-t-2,4-DDE, therefore, was of significance in the genotoxicity of oxidized oil and fumes.