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.

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.

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.

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.

Lactiplantibacillus plantarum-encapsulated microcapsules prepared from okra polysaccharides improved intestinal microbiota in Alzheimer's disease mice.

Background: Okra contains a viscous substance rich in water-soluble material, including fibers, pectin, proteoglycans, gum, and polysaccharides. This study explored the use of okra polysaccharides by microorganisms and their potential to improve microbiota. Methods: The regulation of microcapsules prepared from okra polysaccharides with or without L. plantarum encapsulation on intestinal microbiota was assessed through 16S metagenomic analysis and short-chain fatty acids (SCFAs) in AppNL-G-F/NL-G-F mice (Alzheimer's disease; AD model). Results: We found that Lactobacillaceae and Lactobacillus were majorly regulated by microcapsules prepared from okra polysaccharides in AD mice. Similarly, microcapsules prepared from okra polysaccharides with L. plantarum encapsulation markedly elevated the abundance of Lactobacillaceae and Lactobacillus and increased SCFAs in AD mice. Conclusion: Our results suggest that microcapsules prepared from okra polysaccharides with or without L. plantarum encapsulation may improve intestinal microbiota by elevating Lactobacillus levels in AD mice.

Development of fermented Atemoya (Annona cherimola × Annona squamosa)-Amazake increased intestinal next-generation probiotics.

Akkermansia muciniphila and Faecalibacterium prausnitzii are next-generation probiotics, which has been reported to protect disease and effectively utilize various carbohydrates (starch and pectin) as nutrients for growth. Atemoya exhibiting fruity flavor, which is suitable for enhancing aroma and attenuating unpleasant taste caused by the koji metabolites. Results indicated that malic acid was increased (from 42.4 to 70.1 mg/100 g) in fermented Atemoya-Amazake. In addition, fermented Atemoya-Amazake elevated growthes in A. muciniphila and F. prausnitzii. Similarly, the populations of Parabacteroides (5.7 fold) and Akkermansia (1.66 fold) were elevated by fermented Atemoya-Amazake treatment in an in vitro simulated gastrointestinal system compared to the control group. Results revealed that fermented Atemoya-Amazake modulated the intestinal microbiota through increasing the production of short-chain fatty acids (exhibiting anti-pathogenic activity) for 2.1, 2.5, 2.6, and 2.1 folds in acetic acid, propionic acid, isobutyric acid, and butyric acid, respectively; suggesting this fermented Atemoya-Amazake could be applied in intestinal protection.

Optimization of the Black Garlic Processing Method and Development of Black Garlic Jam Using High-Pressure Processing.

Black garlic has many beneficial effects, and it has a less spicy flavor. However, its aging conditions and related products still need to be further investigated. The present study aims to analyze the beneficial effects under different processing conditions and utilize high-pressure processing (HPP) in the production of black garlic jam. The highest antioxidant activities, including the DPPH scavenging, total antioxidant capacity, and reducing power (86.23%, 88.44%, and A700 = 2.48, respectively), were observed in black garlic that had been aged for 30 days. Similarly, the highest total phenols and flavonoids were observed in black garlic that had been aged for 30 days (76.86 GAE/g dw and 13.28 mg RE/g dw, respectively). The reducing sugar in black garlic was significantly increased to about 380 (mg GE/g dw) after 20 days of aging. The free amino acids in black garlic were decreased time-dependently to about 0.2 mg leucine/g dw after 30 days of aging. For the browning indexes of black garlic, the uncolored intermediate and browning products were increased in a time-dependent manner and reached a plateau at day 30. Another intermediate product in the Maillard reaction, 5-hydroxymethylfurfural (5-HMF), was observed in concentrations that increased to 1.81 and 3.04 (mg/g dw) at day 30 and 40, respectively. Furthermore, the black garlic jam made by HPP was analyzed for its texture and sensory acceptance, showing that a 1:1.5:2 ratio of black garlic/water/sugar was the most preferred and was classified as "still acceptable". Our study suggests suitable processing conditions for black garlic and outlines the prominent beneficial effects after 30 days of aging. These results could be further applied in HPP jam production and increase the diversity of black garlic products.

Tomato-fruit-derived extracellular vesicles inhibit Fusobacterium nucleatum via lipid-mediated mechanism.

Nano-sized extracellular vesicles (EV) are essential for cell communication. Studies on EV from natural sources including edible plants are gaining momentum due to the biological implications. In this study, EV from tomato fruit were isolated by ultracentrifugation and their physical and morphological features along with their biocargo profiles were analyzed. We found that tomato EV promote the growth of probiotic Lactobacillus species, while inhibiting growth of the opportunistic intestinal pathogens Clostridioides difficile and Fusobacterium nucleatum. Tomato EV reversed microbiota dysbiosis caused by F. nucleatum in a simulator of the gut microbiota fermentation model. Phospholipid analysis of tomato EV revealed that the anti-bacterial effect of tomato-EV was driven by the presence of specific lipids in the EV, as demonstrated by lipid depletion and reconstitution experiments. The findings suggest the potential of tomato-derived EV for treating gut microbiota dysbiosis and preventing intestinal bacterial infections.

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.

Antioxidant properties of Lactobacillus-fermented and non-fermented Graptopetalum paraguayense E. Walther at different stages of maturity.

Accumulation of bioactive compounds, during developmental stages of Graptopetalum paraguayense E. Walther, was investigated between 30 and 90days as a function of physiological maturity. Three distinct phases were defined: immature phase (30days), intermediate developmental phase (30-60days), and maturation phase (60-90days). Gallic acid and quercetin, antioxidative bioactive compounds, were identified as biomarkers for determining the optimum physiological maturity stage in G. paraguayense E. Walther. With regard to the antioxidant activity of G. paraguayense E. Walther at different developmental stages, the results indicated that the leaves of immature G. paraguayense E. Walther had the highest 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) (ABTS-), superoxide radical-, and 1,1-diphenyl-2-picrylhydrazyl (DPPH·)-scavenging activities. Fermentation of G. paraguayense E. Walther with Lactobacillus plantarum BCRC 10357 significantly increased the level of flavonoids and total phenolics, including quercetin and gallic acid. Total phenols were the major naturally occurring antioxidant components in lactic acid bacteria-fermented G. paraguayense E. Walther.

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.

Applications of Lactobacillus acidophilus-Fermented Mango Protected Clostridioides difficile Infection and Developed as an Innovative Probiotic Jam.

Clostridioides difficile infection (CDI) is a large intestine disease caused by toxins produced by the spore-forming bacterium C. difficile, which belongs to Gram-positive bacillus. Using antibiotics treatment disturbances in the gut microbiota and toxins produced by C. difficile disrupt the intestinal barrier. Some evidence indicates fecal microbiota transplantation and probiotics may decrease the risk of CDI recurrence. This study aimed to evaluate the efficacy of fermented mango by using the lactic acid bacteria Lactobacillus acidophilus and develop innovative products in the form of fermented mango jam. L. acidophilus-fermented mango products inhibited the growth of C. difficile while promoting the growth of next-generation probiotic Faecalibacterium prausnitzii. Both supernatant and precipitate of mango-fermented products prevented cell death in gut enterocyte-like Caco-2 cells against C. difficile infection. Mango-fermented products also protected gut barrier function by elevating the expression of tight junction proteins. Moreover, L. acidophilus-fermented mango jam with high hydrostatic pressure treatment had favorable textural characteristics and sensory quality.

The applications of Lactobacillus plantarum-derived extracellular vesicles as a novel natural antibacterial agent for improving quality and safety in tuna fish.

Bacteria release membrane vesicles into the extracellular environment but which activity is unclear. We investigated the applications of extracellular vesicles (EVs) isolated from probiotic Lactobacillus plantarum to protect tuna fish against spoilage and quality loss in this study. A significant difference was found in EVs size obtained from L. plantarum after 8, 24, and 48 hr incubation. The L. plantarum-derived EVs were collected and used to confirm the anti-bacterial activity versus Shewanella putrefaciens. Finally, the tuna fish was stored at 4 °C for 5 days after coating with EVs or sodium erythorbate, and the quality indexes were assayed. Results indicated that EVs markedly inhibited oxidation reaction, total volatile base nitrogen (TVBN), peroxide value (PV), malondialdehyde (MDA), and bacteria levels. These results finding out that EVs from L. plantarum may have potential for application in food storage technology. Overall, we indicated this new material may be developed as an anti-bacterial agent for prolonging the shelf life of tuna fish.

Optimal conditions for cordycepin production in surface liquid-cultured Cordyceps militaris treated with porcine liver extracts for suppression of oral cancer.

Cordycepin is one of the most crucial bioactive compounds produced by Cordyceps militaris and has exhibited antitumor activity in various cancers. However, industrial production of large amounts of cordycepin is difficult. The porcine liver is abundant in proteins, vitamins, and adenosine, and these ingredients may increase cordycepin production and bioconversion during C. militaris fermentation. We observed that porcine liver extracts increased cordycepin production. In addition, air supply (2 h/d) significantly increased the cordycepin level in surface liquid-cultured C. militaris after 14 days. Moreover, blue light light-emitting diode irradiation (16 h/d) increased cordycepin production. These findings indicated that these conditions are suitable for increasing cordycepin production. We used these conditions to obtain water extract from the mycelia of surface liquid-cultured C. militaris (WECM) and evaluated the anti-oral cancer activity of this extract in vitro and in vivo. The results revealed that WECM inhibited the cell viability of SCC-4 oral cancer cells and arrested the cell cycle in the G2/M phase. Oxidative stress and mitochondrial dysfunction (mitochondrial fission) were observed in SCC-4 cells treated with WECM for 12 hours. Furthermore, WECM reduced tumor formation in 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis through the downregulation of proliferating cell nuclear antigen, vascular endothelial growth factor, and c-fos expression. The results indicated that porcine liver extracts irradiated with blue light light-emitting diode and supplied with air can be used as a suitable medium for the growth of mycelia and production of cordycepin, which can be used in the treatment of oral cancer.

The neuronal protection of a zinc-binding protein isolated from oyster.

Mitochondrial function is applied as oxidative stress and neuronal damage index. In this study, d-galactose was used to induce free radicals production and neuronal damage in HN-h cells, and the effect of novel 43 kDa protein isolated from oyster on anti-mitochondrial dysfunction and zinc-binding ability were evaluated. Crystal violet stain results indicated zinc-binding protein of oyster (ZPO) attenuated neuronal cell death induced by 100 mM of d-galactose on HN-h cells in a dose-dependent manner. ZPO alleviated mitochondrial inactivation, mitochondrial membrane potential decreasing, oxidative stress, and fusion/fission state in non-cytotoxic concentration of d-galactose (50 mM)-treated HN-h cells. ZPO treatment recovered metallathionein-3 (MT-3) decrease and inhibited ß- and γ-secretase as well as amyloid beta (Aß) accumulation in HN-h cells caused by d-galactose induction. These results suggest ZPO could avoid oxidative stress and is a functional protein for zinc concentration maintainability, which has potential for development of functional foods for neuronal protection.

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.

Trichostatin A induces bladder cancer cell death via intrinsic apoptosis at the early phase and Sp1­survivin downregulation at the late phase of treatment.

Histone deacetylase (HDAC) inhibitors have been widely shown to result in cancer cell death. The present study investigated the mechanisms underlying the antitumor effects of the phytochemical trichostatin A (TSA), a classic pan-HDAC inhibitor, in 5,637 urinary bladder cancer cells. It was found that TSA caused cell cycle arrest at the G2/M and G1 phase accompanied by reduced expression of cyclin D1 and upregulated induction of p21. In addition, TSA induced morphological changes, reduced cell viability and apoptotic cell death in 5,637 cells through caspase-3 activation followed by PARP cleavage. The loss of mitochondrial membrane potential (MMP) indicated that TSA induced apoptosis in 5,637 cells through the intrinsic mitochondrial pathway. TSA significantly suppressed Akt activity at 12 h after treatment, suggesting that the apoptosis in the early phase was mediated by Akt inhibition. In addition, the protein level of transcription factor Sp1 was decreased at 24 h after TSA treatment, which likely led to the downregulation of survivin gene expression, and then contributed to the antitumor activity of TSA. Taken together, the present study delineated that TSA-induced growth inhibition and apoptosis in 5,637 cells was associated with pAKT inhibition and MMP loss at the early phase, followed by downregulation of Sp1 and survivin at the late phase of treatment.

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.

Antioxidation, angiotensin converting enzyme inhibition activity, nattokinase, and antihypertension of Bacillus subtilis (natto)-fermented pigeon pea.

Because of the high incidence of cardiovascular diseases in Asian countries, traditional fermented foods from Asia have been increasingly investigated for antiatherosclerotic effects. This study investigated the production of nattokinase, a serine fibrinolytic enzyme, in pigeon pea by Bacillus subtilis fermentation. B. subtilis 14714, B. subtilis 14715, B. subtilis 14716, and B. subtilis 14718 were employed to produce nattokinase. The highest nattokinase activity in pigeon pea was obtained using B. subtilis 14715 fermentation for 32 hours. In addition, the levels of antioxidants (phenolics and flavonoids) and angiotensin converting enzyme inhibitory activity were increased in B. subtilis 14715-fermented pigeon pea, compared with those in nonfermented pigeon pea. In an animal model, we found that both water extracts of pigeon pea (100 mg/kg body weight) and water extracts of B. subtilis-fermented pigeon pea (100 mg/kg body weight) significantly improved systolic blood pressure (21 mmHg) and diastolic blood pressure (30 mmHg) in spontaneously hypertensive rats. These results suggest that Bacillus-fermented pigeon pea has benefits for cardiovascular health and can be developed as a new dietary supplement or functional food that prevents hypertension.

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.