Compounds from the Petroleum Ether Extract of Wedelia chinensis with Cytotoxic, Anticholinesterase, Antioxidant, and Antimicrobial Activities.

Wedelia chinensis is a folk medicine used in many Asian countries to treat various ailments. Earlier investigations reported that the petroleum ether extract of the plant has potential biological activity, but the compounds responsible for activity are not yet completely known. Therefore, the current work was designed to isolate and characterize the compounds from the petroleum ether extract and to study their bioactivities. Four compounds including two diterepenes (-) kaur-16α-hydroxy-19-oic acid (1) and (-) kaur-16-en-19-oic acid (2), and two steroids ß-sitosterol (3), and cholesta-5,23-dien-3-ol (4) were isolated and characterized. Among the compounds, the diterpenes were found to have more biological activities than the steroidal compounds. Compound 1 showed the highest cytotoxicity with LC50 of 12.42 ± 0.87 µg/mL. Likewise, it possesses good antioxidant activity in terms of reducing power. On the contrary, compound 2 exerted the highest antiacetylcholinesterase and antibutyrylcholinesterase activity. Both the diterpenes showed almost similar antibacterial and antifungal activity. The identification of diterpenoid and steroid compounds with multifunctional activities suggests that W. chinensis may serve as an important source of bioactive compounds which should be further investigated in animal model for therapeutic potential in the treatment of different chronic diseases.

Acetylcholinesterase Inhibitory and Antioxidant Activity of the Compounds Isolated from Vanda roxburghii.

Vanda roxburghii has been used in traditional medicine to treat nervous system disorders including Alzheimer's disease (AD). We reported earlier a high acetylcholinesterase inhibitory and antioxidant activity in the chloroform fraction of this plant. Therefore, this study was designed to explore the compounds with acetylcholinesterase inhibitory and antioxidant activities from the chloroform fraction of Vanda roxburghii. Phytochemical investigation led to the isolation for the first time of a fatty acid ester: methyl linoleate (1), and three phenolics: syringaldehyde (2), vanillin (3), and dihydroconiferyl dihydro-p-coumarate (4) along with the previously reported compound gigantol (5). Among the isolates, vanillin (3) and dihydroconiferyl dihydro-p-coumarate (4) were found to significantly inhibit the activity of acetylcholinesterase, scavenge the free radicals, exhibit the reducing power and total antioxidant activity, and effectively reduce the peroxidation of lipid. Gigantol (5) and syringaldehyde (2), despite lacking the activity against acetylcholinesterase, exhibited antioxidant activity. Among the compounds, gigantol (5) appeared to be the most potent antioxidant. These findings revealed that V. roxburghii contained compounds with potential acetylcholinesterase inhibitory and antioxidant activity, which support its traditional use in the treatment of AD.

Higher Fertilizer Inputs Increase Fitness Traits of Brown Planthopper in Rice.

Rice (Oryza sativa L.) is the primary staple food source for more than half of the world's population. In many developing countries, increased use of fertilizers is a response to increase demand for rice. In this study, we investigated the effects of three principal fertilizer components (nitrogen, phosphorus and potassium) on the development of potted rice plants and their effects on fitness traits of the brown planthopper (BPH) [Nilaparvata lugens (Stål) (Homoptera: Delphacidae)], which is a major pest of rice in Bangladesh and elsewhere. Compared to low fertilizer inputs, high fertilizer treatments induced plant growth but also favored BPH development. The BPH had higher survival, developed faster, and the intrinsic rate of natural increase (r m ) was higher on well-fertilized than under-fertilized plants. Among the fertilizer inputs, nitrogen had the strongest effect on the fitness traits of BPH. Furthermore, both the "Plant vigor hypothesis" and the "Plant stress hypothesis" were supported by the results, the former hypothesis more so than the latter. These hypotheses suggest that the most suitable/attractive hosts for insect herbivores are the most vigorous plants. Our findings emphasized that an exclusive focus on yield increases through only enhanced crop fertilization may have unforeseen, indirect, effects on crop susceptibility to pests, such as BPH.

Evaluation of Iron Store by Serum Ferritin in Healthy Blood Donors of Bangladesh.

Iron stores in the body exist primarily in the form of ferritin. Small amounts of ferritin secreted into the plasma and plasma ferritin is positively correlated with the size of the total body iron stores. The present study conducted to determine the iron status using the serum ferritin level among healthy Bangladeshi blood donors. The present cross sectional study was conducted in the Department of Transfusion Medicine, Dhaka Medical College, Dhaka, Bangladesh from July 2011 to June 2012. Blood donor signed informed consent and has satisfactory pre-donation health assessment and satisfactory post-donation blood test results were included in the study. Full blood counts were performed within 4 hours of collection using an automated haematology analyzer. Serum ferritin was measured using a validated enzyme immunoassay. Data were analyzed using SPSS version 16 (SPPS Incorporation, Chicago, IL, USA). P value <0.05 was considered as statistically significant. Total 100 blood donors were included in the study, among them 88 were male and 12 were female. Mean±SD of the age of the respondents was 26.8±5.9 years with a range of 19 to 45 years. Mean±SD of heamoglobin level (gm/dl) and total count of Red Blood Cell (million/cmm) were 14.1±1.4 and 5.1±0.4 respectively. Mean±SD of serum ferritin level (ng/ml) was 96.4±69.0ng/ml with a range of 4.1ng/ml to 298.7ng/ml. Among the respondents 9.0% had depleted iron store, 7.0 reduced iron store and 84.0% had normal iron store. Among the respondents 5.0% had iron deficiency anaemia in term of serum ferritin level. Statistically significant difference of serum ferritin level observed between male and female and donors with and without history of previous blood donation. Among the healthy blood donors of Bangladesh abnormal serum ferritin is highly prevalent among blood donors specially among female. Monitoring of iron stores by serum ferritin seems justified in order to identify those with depleted iron stores who will benefit from iron supplementation.

Response of Adult Brown Planthopper Nilaparvata lugens (Stål) to Rice Nutrient Management.

Nitrogen (N) limitation is well documented for the brown planthopper (BPH) Nilaparvata lugens (Stål), but phosphorus (P) and potassium (K) limitation is poorly studied. We studied the effects of N, P, and K application on chemical composition of rice plants and its consequences on life parameters-adult longevity, fecundity, and egg hatchability of BPH. Life parameters of BPH were regressed as function of plant chemical composition. A completely randomized design with four replicates in a factorial scheme was used considering N, P, and K levels as factors. Nitrogen application increased N and soluble proteins (SP) and decreased silicon (Si) content in the plants resulting in increased adult longevity, fecundity, and egg hatchability of BPH. Phosphorus fertilization increased P content and showed markedly increased fecundity, but not egg hatchability or adult longevity. Significant interaction between N and P was observed for fecundity of BPH. Potassium supplementation increased K content but reduced N, Si, SP, and total free sugars (TFS) content in the plants, but it had no significant effect on life parameters of BPH. The association of BPH life parameters with N, SP, TFS, and P content was significant and positive, but it was negative with the content of Si. Thus, N and P fertilization on rice plants enhanced BPH fitness. In conclusion, judicious nutrient application can be helpful in avoiding generalized infestation of BPH to rice.

Inducing pluripotency in vitro: recent advances and highlights in induced pluripotent stem cells generation and pluripotency reprogramming.

Induced pluripotent stem cells (iPSCs) are considered patient-specific counterparts of embryonic stem cells as they originate from somatic cells after forced expression of pluripotency reprogramming factors Oct4, Sox2, Klf4 and c-Myc. iPSCs offer unprecedented opportunity for personalized cell therapies in regenerative medicine. In recent years, iPSC technology has undergone substantial improvement to overcome slow and inefficient reprogramming protocols, and to ensure clinical-grade iPSCs and their functional derivatives. Recent developments in iPSC technology include better reprogramming methods employing novel delivery systems such as non-integrating viral and non-viral vectors, and characterization of alternative reprogramming factors. Concurrently, small chemical molecules (inhibitors of specific signalling or epigenetic regulators) have become crucial to iPSC reprogramming; they have the ability to replace putative reprogramming factors and boost reprogramming processes. Moreover, common dietary supplements, such as vitamin C and antioxidants, when introduced into reprogramming media, have been found to improve genomic and epigenomic profiles of iPSCs. In this article, we review the most recent advances in the iPSC field and potent application of iPSCs, in terms of cell therapy and tissue engineering.

Effect of dietary citric acid on the performance and mineral metabolism of broiler.

The objective of this study was to investigate the effect of dietary citric acid (CA) on the performance and mineral metabolism of broiler chicks. A total of 1720 Ross PM3 broiler chicks (days old) were randomly assigned to four groups (430 in each) and reared for a period of 35 days. The diets of groups 1, 2, 3 and 4 were supplemented with 0%, 0.25%, 0.75% or 1.25% CA by weight respectively. Feed and faeces samples were collected weekly and analysed for acid insoluble ash, calcium (Ca), phosphorus (P) and magnesium (Mg). The pH was measured in feed and faeces. At the age of 28 days, 10 birds from each group were slaughtered; tibiae were collected from each bird for the determination of bone mineral density, total ash, Ca, P, Mg and bone-breaking strength, and blood was collected for the measurement of osteocalcin, serum CrossLaps(®), Ca, P, Mg and 1,25(OH)(2)Vit-D in serum. After finishing the trial on day 37, all chicks were slaughtered by using the approved procedure. Birds that were fed CA diets were heavier (average body weights of 2030, 2079 and 2086 g in the 0.25%, 0.75% and 1.25% CA groups, respectively, relative to the control birds (1986 g). Feed conversion efficiency (weight gain in g per kg of feed intake) was also higher in birds of the CA-fed groups (582, 595 and 587 g/kg feed intake for 0.25%, 0.75% and 1.25% CA respectively), relative to the control birds (565 g/kg feed intake). The digestibility of Ca, P and Mg increased in the CA-fed groups, especially for the diets supplemented with 0.25% and 0.75% CA. Support for finding was also indicated in the results of the analysis of the tibia. At slaughter, the birds had higher carcass weights and higher graded carcasses in the groups that were fed the CA diets. The estimated profit margin was highest for birds fed the diet containing 0.25% CA. Birds of the 0.75% CA group were found to have the second highest estimated profit margin. Addition of CA up to a level of 1.25% of the diet increased performance, feed conversion efficiency, carcass weight and carcass quality, but only in numerical terms. The addition of CA up to 0.75% significantly increased the digestibility of macro minerals, bone ash content, bone mineral density and bone strength of the broiler chicks. It may, therefore, be concluded that the addition of 0.75% CA in a standard diet is suitable for growth, carcass traits, macromineral digestibility and bone mineral density of broiler chicks.

Appendico-colic fistula complicating appendicitis in cystic fibrosis.

The case of a boy with cystic fibrosis who presented with an unusual complication of appendicitis is reported. Delayed presentation, with complications of appendicitis such as perforation and abscess formation, is not uncommon in cystic fibrosis; however, this case represents the first report of an isolated appendico-colic fistula following appendicitis in association with cystic fibrosis.

Effect of citric acid, avilamycin, and their combination on the performance, tibia ash, and immune status of broilers.

The aim of this study was to determine the effect of the supplementation of an organic acid (citric acid), antibiotic growth promoter (avilamycin), and their combination for a period of 35 d on the growth, feed efficiency, carcass yield, tibia ash, and immune status of broilers. One hundred sixty 1-d-old broiler chicks (Hubbard Classic) were randomly distributed into 4 groups with 4 replicate cages having 10 birds in each. A corn-soybean-based diet was used as the basal diet (control). The basal diet was supplemented with an organic acid (citric acid, 0.5%), an antibiotic growth promoter (avilamycin, 0.001%), and their combination in other groups. The highest BW was attained in citric acid-fed chicks (1,318 g), which was significantly (P < 0.05) higher than control chicks (1,094 g) or avilamycin-fed chicks (1,217 g). The combination-fed chicks showed similar weight (1,246 g) as citric acid- or avilamycin-fed chicks (P > 0.05). Total feed intake was higher in citric acid-fed chicks compared with antibiotic-supplemented chicks. The addition of citric acid improved feed conversion efficiency (g of weight gain/ kg of feed intake) significantly (P < 0.05) compared with control chicks or its combination with avilamycin. Higher carcass weights were found in chicks fed the combination diet. Supplementation of citric acid increased tibia ash percentage significantly (P < 0.05) compared with controls. Addition of citric acid reduced the pH of the formulated diets. An improvement of immune status was detected by densely populated immunocompetent cells in the lamina propria and submucosa of cecal tonsils and ileum and also in the cortex and medulla of bursa follicles in citric acid-supplemented chicks. Supplementation of citric acid at 0.5% in the diet had positive effects on growth, feed intake, feed efficiency, carcass yield, bone ash, and immune status of broilers. Therefore, citric acid might be a useful additive instead of antibiotic growth promoters such as avilamycin, considering performance and health status of broilers.

Multicenter, randomized study of the efficacy and safety of intravenous iclaprim in complicated skin and skin structure infections.

Iclaprim is a novel antibacterial agent that is currently in development for the treatment of complicated skin and skin structure infections (cSSSI). Iclaprim specifically and selectively inhibits bacterial dihydrofolate reductase, a critical enzyme in the bacterial folate pathway, and exhibits an extended spectrum of activity against various resistant pathogens, including methicillin (meticillin)-resistant Staphylococcus aureus (MRSA). The objective of this randomized, double-blind phase II study was to compare the efficacy and safety of iclaprim to those of vancomycin in patients with cSSSI. Patients were randomized to receive 0.8 mg iclaprim/kg of body weight, 1.6 mg/kg iclaprim, or 1 g vancomycin twice a day for 10 days. Clinical cure rates for the 0.8- and 1.6-mg/kg-iclaprim treatment groups were comparable to that for the vancomycin treatment group (26/28 patients [92.9%], 28/31 patients [90.3%], and 26/28 patients [92.9%], respectively). Iclaprim also showed high microbiological eradication rates. Iclaprim exhibited an eradication rate of 80% and 72% versus 59% observed with vancomycin for S. aureus, the pathogen most frequently isolated at baseline. Five MRSA cases were observed, four in the 0.8-mg/kg-iclaprim arm and one in the vancomycin arm, and all were both clinically and microbiologically cured. Iclaprim exhibited a safety profile similar to that of vancomycin, an established drug for the treatment of cSSSI. Results from this study indicate that iclaprim is a promising new therapy for the treatment of cSSSI, in particular those caused by S. aureus, including MRSA.

Impact of zinc supplementation on subsequent morbidity and growth in Bangladeshi children with persistent diarrhoea.

This study was conducted to explore whether supplementation of zinc to children during persistent diarrhoea has any subsequent effect on morbidity and growth. A prospective follow-up study was conducted among children, aged 3-24 months, with persistent diarrhoea, who participated earlier in a double-blind randomized placebo-controlled trial. During persistent diarrhoea, children were randomly allocated to receive either zinc in multivitamin syrup or only multivitamin syrup for two weeks. After recovering from diarrhoea, 76 children in the multi-vitamin syrup and 78 children in the zinc plus multivitamin syrup group were followed up for subsequent morbidity and growth. Weekly morbidity and two-weekly anthropometric data were collected for the subsequent 12 weeks. Data showed that episodes and duration of diarrhoea were reduced by 38% and 44% respectively with supplementation of zinc. There was no significant difference in the incidence or duration of respiratory tract infection between the zinc-supplemented and the non-supplemented group. Improved linear growth was observed in underweight children (weight-for-age <70% of the National Center for Health Statistics standard) who received zinc compared to those who did not receive.

Folic acid supplementation on red kidney bean-induced diarrhoea and enteric bacterial translocation into mesenteric lymph nodes in rats: a pilot study.

UNLABELLED: Deaths following childhood diarrhoea, a major health problem in developing countries, are often associated with malnutrition and septicaemic complications. Folic acid has been used in the treatment of acute and chronic diarrhoea in the tropics. Using a rat model, we evaluated the protective effect of large doses of folic acid on diarrhoea, small intestinal bacterial overgrowth and translocation of enteric bacteria into mesenteric lymph nodes induced by a raw red kidney bean-based diet containing lectin (phytohemagglutinin). Long-Evans rats in 2 groups of 5 each (60 g to 70 g in weight, 28 d old) were used. All 10 rats, individually kept in metabolic cages, received a raw red kidney bean-based diet for 10 d, and 5 of them also received a daily folic acid supplement (160 microg/g feed) both during and for 10 d before the experiment. The faecal weight was measured and a quantitative aerobic bacterial culture of the small intestinal mucosal scrapings and of the mesenteric lymph nodes was made. Folic acid supplementation did not reduce faecal output nor did it prevent loss of body weight associated with lectin-induced diarrhoea. However, the mean total count of enteric bacteria translocated to the mesenteric lymph nodes was significantly reduced in the supplemented rats (1.27 +/- 0.61 vs 2.66 +/- 0.84, p = 0.028) and a trend towards reduced bacterial count in the small intestinal mucosal scrapings (0.40 +/- 0.89 vs 1.42 +/- 1.31, p = 0.16) was documented. A significant positive correlation was also seen between the bacterial count in the jejunal mucosal scrapings and in the mesenteric lymph nodes. CONCLUSION: Although large-dose folic acid supplementation did not prevent diarrhoea and malnutrition induced by a lectin-based diet, it substantially reduced the count of enteric bacteria translocated into the mesenteric lymph nodes and showed a trend towards a reduction in indigenous bacteria adhering to jejunal mucosa. These findings could be of relevance in the prevention of septicaemic complications following many clinical conditions, including diarrhoea with malnutrition in children known to have bacteraemic and septicaemic complications.

Low-density lipoprotein (LDL)-induced monocyte-endothelial cell adhesion, soluble cell adhesion molecules, and autoantibodies to oxidized-LDL in chronic renal failure patients on dialysis therapy.

Premature atherosclerosis is a major cause of morbidity and mortality in chronic renal failure patients undergoing dialysis. In this study, we compared autoantibodies to oxidized low-density lipoprotein (OX-LDL), soluble cell adhesion molecules (CAMs), and the effect of both LDL and OX-LDL on monocyte endothelial cell adhesion in chronic renal failure patients on hemodialysis (HD, n = 16) and peritoneal dialysis (PD, n = 17) compared with matched healthy control subjects (C, n = 17). In addition, we studied the effect of supplementation with RRR-alpha-tocopherol (AT) 800 IU/d for 12 weeks on the above measures. LDL and OX-LDL induced adhesion of U937 cells to cultured endothelium, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intracellular adhesion molecule-1 (sICAM-1), and soluble E-selectin (sE-selectin); autoantibodies to OX-LDL and markers of lipid peroxidation were determined before and after AT supplementation. Native LDL from PD patients induced greater monocyte-endothelial cell adhesion than LDL from C subjects (43.8% +/- 17.0% v25.3% +/- 17.7%, respectively, P = .0028). OX-LDL from chronic renal failure patients on both PD and HD stimulated greater adhesion than OX-LDL from the C subjects (68.0% +/- 18.5% and 57.6% +/- 15.1% v 40.9% +/- 17.3%, respectively, P < .01); OX-LDL from PD patients induced greater adhesion than that from HD patients (P < .01). Plasma methylglyoxal levels were significantly increased in both HD and PD groups, with higher levels in the HD group. Chronic renal failure patients on HD and PD also had higher levels of plasma sVCAM-1 and sE-selectin than C subjects (P < .01), indicating endothelial activation. Titers of autoantibodies to OX-LDL were not elevated in renal failure patients. Supplementation with AT 800 IU/d for 12 weeks, while resulting in significant enrichment with AT in LDL, did not have a significant effect on any of the parameters studied. This study makes the novel observation that the LDL of chronic renal failure patients on HD and PD appears to be potentially more atherogenic, since it induces greater monocyte-endothelial cell adhesion.

Alpha-tocopherol supplementation decreases the oxidative susceptibility of LDL in renal failure patients on dialysis therapy.

Atherosclerotic cardiovascular disease is the leading cause of death in patients with end stage renal disease (ESRD) who have undergone dialysis treatment. The oxidation of low density lipoprotein (LDL) appears to be a crucial step in the pathogenesis of atherosclerosis. The increased oxidative stress and attendant increased oxidizability of lipoproteins, such as LDL could contribute to the accelerated atherosclerosis in dialysis patients. Since alpha-tocopherol (AT) is the major antioxidant in LDL, the aim of the present study was to test the effectiveness of RRR-AT supplementation (800 I.U. per day) for 12 weeks on the susceptibility of LDL to oxidation. The study subjects comprised patients with chronic renal failure on hemodialysis (HD), peritoneal dialysis (PD), and age and sex matched controls (C). Plasma fatty acids, lipoproteins and AT levels were measured in these subjects before and after supplementation. Also, LDL AT and oxidizability was studied. LDL was isolated by ultracentrifugation at baseline and after 12 weeks of supplementation, and subjected to a 5-h time course of copper catalyzed oxidation. Oxidation was measured by the formation of conjugated dienes (CD) and lipid peroxides (LP). Supplementation with AT did not alter the plasma lipid or lipoprotein profile of these subjects. Plasma lipid-standardized AT and LDL AT concentrations were not different among the groups at baseline. AT supplementation significantly increased plasma lipid-standardized AT (C=150%, HD=149%, PD=217%, P<0.001) and LDL AT concentrations (C=94%, HD=94%, PD=135%, P<0.003). AT enrichment of LDL resulted in a significant prolongation in conjugated diene lag phase in all groups (C=34%, HD=21%, PD=54%, P<0.02). Lipid peroxide lag phase was also increased significantly in C (27%,) and PD (40%) groups after AT supplementation (P<0.01). There was a significant positive correlation between plasma lipid standardized AT and lag phase (r=0. 54, P=0.0003). Overall, AT decreased the susceptibility of LDL to oxidation in patients with chronic renal failure but the benefit appears to be greater in patients on PD. Therefore, AT supplementation may also provide a measure of protection against CAD in patients with chronic renal failure on dialysis therapy.

Short-chain fatty acids improve clinical, pathologic, and microbiologic features of experimental shigellosis.

Because of the metabolic and antibacterial actions of short-chain fatty acids (SCFA), their roles in modifying the clinicopathologic features of shigellosis were evaluated in a rabbit model of shigellosis. Acute colitis was induced in adult rabbits by intracolonic administration of Shigella flexneri 2a. After 24 h, rabbits were given 6-h colonic infusions of SCFA (acetate, propionate, n-butyrate; 60:30:40 mM) or SCFA-free solution (control); groups of rabbits were killed in batches of 2 or 3 animals at 24, 48, 72, and 96 h after treatment, for histologic and bacteriologic assessment. SCFA significantly reduced fecal blood and mucus and improved clinical symptoms. Histologically, SCFA significantly (P<.01) reduced mucosal congestion, cellular infiltration, and necrotic changes. SCFA also significantly (P<.05) reduced the number of shigellae in the colon. No such improvements occurred in the control group. SCFA may be useful agents in improving clinicopathologic features of shigellosis and should be clinically evaluated.

alpha-Tocopherol enrichment of monocytes decreases agonist-induced adhesion to human endothelial cells.

BACKGROUND: Monocyte-endothelium adhesion is a crucial early event in atherogenesis. Several reports indicate that alpha-tocopherol (AT) is a potent antioxidant in plasma and LDL and also has intracellular effects that are antiatherogenic. Recently, it has been shown that AT supplementation results in decreased monocyte-endothelial cell adhesion. However, there is a paucity of data on the mechanisms by which AT inhibits adhesion of monocytes. We studied the effect of AT enrichment of a human monocytic cell line, U937, on adhesion to human umbilical vein endothelial cells (HUVECs). METHODS AND RESULTS: Both lipopolysaccharide (LPS)- and N-formyl-methionyl-leucyl-phenylalanine (FMLP)-stimulated U937 adhesion to HUVECs were studied. AT (50 and 100 micromol/L) significantly decreased adhesion of both LPS- and FMLP-stimulated U937 cells to HUVECs (LPS-treated cells, P<0.0125; FMLP-treated cells, P<0.05). Expression of the adhesion molecules CD11a, CD11b, CD11c, very late antigen-4 (VLA-4), and L-selectin, as assessed by flow cytometry, was increased in the stimulated U937 cells, and AT resulted in significant reduction in the expression of CD11b and VLA-4. In addition, activation of the transcription factor nuclear factor-kappaB (NF-kappaB), as assessed by gel shift assays, was inhibited by pretreatment with AT in LPS-treated U937 cells. CONCLUSIONS: AT significantly decreases adhesion of activated monocytes to endothelial cells by decreasing expression of CD11b and VLA-4 on monocytes, possibly by inhibiting the activation of NF-kappaB.

The protective role of glutathione peroxidase in apoptosis induced by reactive oxygen species.

Selenium-dependent glutathione peroxidase (GPx) plays a protective role in oxidative stress-induced apoptosis. In this study, we demonstrated that MDBK cells, a bovine renal epithelial cell line, exhibited internucleosomal DNA fragmentation characteristic of apoptotic cell death under selenium-deficient conditions with lower doses of hydrogen peroxide (H2O2) than under selenium-supplemented ones. This was due to a decreased amount of GPx in the cells under selenium-deficient conditions, because other antioxidative enzyme activities were not affected by the selenium supplementation. Cumene hydroperoxide also induced DNA fragmentation in selenium-deficient cells but no ladder formation was observed. Flow cytometric analysis showed that selenium-deficient cells were less capable of scavenging intracellular peroxides after exposure to exogenous H2O2 than selenium-supplemented ones. In contrast, there was no difference in viability between selenium-supplemented and non-supplemented cells in cell survival after exposure to menadione, which activates the electron transport system and increases intracellular superoxide radicals. Clofibrate, a peroxisomal proliferator and an inducer of catalase (CAT), partially protected both Se-deficient and Se-supplemented cells from exogenous H202. We concluded that selenium-deficient cells were more easily brought to apoptotic cell death by peroxides, but not by superoxide radicals, than selenium-supplemented ones and that CAT could compensate for the depletion of GPx to a certain degree by scavenging H2O2.