Effects of Passiflora edulis (Yellow Passion) on Serum Lipids and Oxidative Stress Status of Wistar Rats

The aim of this study was to evaluate the effects of Passiflora edulis f. flavicarpa Degener (yellow passion) juice on the lipid profile and oxidative stress status of Wistar rats. Adult male Wistar rats were divided in two groups (n = 8 animals per group): the control group, which received water, and the treated group, which was given P. edulis juice (1,000 mg/kg). Both groups received by gavage treatment twice a day for 28 days. The treated group showed an increased high-density lipoprotein-cholesterol level and decreased low-density lipoprotein-cholesterol and free fatty acid levels compared with the control group. Levels of triglycerides and and very low-density lipoprotein-cholesterol, superoxide dismutase activity, and total glutathione concentration were not statistically different between the two groups, but the thiobarbituric acid-reactive substances concentration (indicating lipid peroxidation) decreased in the treated group. These findings suggests that P. edulis juice in the experimental conditions used showed beneficial effects on lipid profile and improved lipid peroxidation in Wistar rats.

Effect of Ginkgo biloba on the reproductive outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats

The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. on day 21 of pregnancy, the adult rats (weighing approximately 250 ± 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 ± 0.2) and SOD (G3 = 223.0 ± 84.7; G4 = 146.1 ± 40.8), and decreased fetal CAT activity (G3 = 22.4 ± 10.6; G4 = 34.4 ± 14.1) and GSH-t (G3 = G4 = 0.3 ± 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 ± 0.2 and SOD = 274.1 ± 80.3; fetal CAT = 92.6 ± 82.7 and GSH-t = 0.6 ± 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days).

Neonatally-induced diabetes: lipid profile outcomes and oxidative stress status in adult rats

INTRODUÇÃO: Modelos experimentais são desenvolvidos com propósito de ampliar o entendimento dos mecanismos fisiopatológicos envolvidos no diabete. Os achados experimentais levam ao desenvolvimento de tratamentos alternativos para a manutenção das condições metabólicas normais. Existem vários estudos sobre o diabete induzido por streptozotocin mimetizando o quadro clínico do DM2. No entanto, a interação entre os níveis de glicose, perfil lipídico e estresse oxidativo nestes animais são escassos. Portanto, o objetivo do trabalho foi avaliar estes parâmetros em ratas Wistar adultas com diabete induzido com streptozotocin no período neonatal. MÉTODOS: Fêmeas recém-nascidas receberam streptozotocin (70mg/Kg, ip) no 5º dia de vida (n5-STZ). A glicemia foi medida no terceiro e quarto meses de vida dos animais. No final do quarto mês de vida, amostras de sangue foram coletadas e processadas para a dosagem de lipídios e marcadores de estresse oxidativo. RESULTADOS: A glicemia das ratas do grupo n5-STZ foi significativamente maior comparada às ratas do grupo controle (p<0,05). Não houve alteração nos níveis de colesterol total e triglicérides, peroxidação lipídica (TBARS), atividade da SOD e determinação da GSH-t (p>0,05) nas ratas n5-STZ em relação às ratas do grupo controle. No entanto, houve diminuição significativa no HDL-colesterol (p<0,05). CONCLUSÃO: Este modelo de indução de diabete em ratas causou hiperglicemia (120-360mg/dL), caracterizando o diabete moderado. Essa glicemia levou a alterações no HDL-colesterol, a qual não foi suficiente para prejudicar a atividade das enzimas antioxidantes ou marcadores da peroxidação lipídica na vida adulta. Além disso, esta investigação experimental contribuiu para entender os diferentes resultados encontrados em outros modelos deindução do diabete moderado em animais de laboratório, como também para a melhor compreensão dos mecanismos fisiopatológicos do diabete moderado ou da hiperglicemia em humanos.

Vascular adaptive responses to physical exercise and to stress are affected differently by nandrolone administration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An Arabidopsis Mitochondrial Uncoupling Protein Confers Tolerance to Drought and Salt Stress in Transgenic Tobacco Plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of N-acetylcysteine on sucrose-rich diet-induced hyperglycaemia, dyslipidemia and oxidative stress in rats

This study examined whether sucrose-rich diet (SRD)-induced hyperglycaemia, dyslipidemia and oxidative stress may be inhibited by N-acetylcysteine (C5H9-NO3S), an organosulfur from Allium plants. Male Wistar 40 rats were divided into four groups (n = 10): (C) given standard chow and water; (N) receiving standard chow and 2 mg/l N-acetylcysteine in its drinking water; (SRD) given standard chow and 30% sucrose in its drinking water; and (SRD-N) receiving standard chow, 30% sucrose and N-acetylcysteine in its drinking water. After 30 days of treatment, SRD rats had obesity with increased abdominal circumference, hyperglycaemia, by dyslipidemia and hepatic triacylglycerol accumulation. These adverse effects were associated with oxidative stress and depressed lipid degradation in hepatic tissue. The SRD adverse effects were not observed in SDR-N rats. N-Acetylcysteine reduced the oxidative stress, enhancing glutathione-peroxidase activity, and normalizing lipid hydroperoxyde, reduced glutathione and superoxide dismutase in hepatic tissue of SRD-N rats. The beta-hydroxyacyl coenzyme-A dehydrogenase and citrate-synthase activities were increased in SRD-N rats, indicating enhanced lipid degradation in hepatic tissue as compared to SRD. SRD-N rats had reduced serum oxidative stress and diminished glucose, triacylglycerol, very-low-density lipoprotein (VLDL), oxidized low-density lipoprotein (alpha-LDL) and cholesterol/highdensity lipoprotein (HDL) ratio in relation to SRD. In conclusion, NAC offers promising therapeutic values in prevention of dyslipidemic profile and alleviation of hyperglycaemia in high-sucrose intake condition by improving antioxidant defences. N-Acetylcysteine had also effects preventing metabolic shifting in hepatic tissue, thus enhancing fat degradation and reducing body weight gain in conditions of excess sucrose intake. The application of this agent in food system via exogenous addition may be feasible and beneficial for antioxidant protection. (c) 2006 Elsevier B.V All rights reserved.

Evaluation of lipid profile and oxidative stress in STZ-induced rats treated with antioxidant vitamin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ultraviolet-B and water stress effects on growth, gas exchange and oxidative stress in sunflower plants

The effects and interaction of drought and UV-B radiation were studied in sunflower plants (Helianthus annuus L. var. Catissol-01), growing in a greenhouse under natural photoperiod conditions. The plants received approximately 1.7 W m(-2) (controls) or 8.6 W m(-2) (+UV-B) of UV-B radiation for 7 h per day. The UV-B and water stress treatments started 18 days after sowing. After a period of 12 days of stress, half of the water-stressed plants (including both UV-B irradiated or non-irradiated) were rehydrated. Both drought and UV-B radiation treatments resulted in lower shoot dry matter per plant, but there was no significant interaction between the two treatments. Water stress and UV-B radiation reduced photosynthesis, stomatal conductance and transpiration. However, the amplitude of the effects of both stressors was dependent on the interactions. This resulted in alleviation of the negative effect of drought on photosynthesis and transpiration by UV-B radiation as the water stress intensified. Intercelluar CO(2) concentration was initially reduced in all treatments compared to control plants but it increased with time. Photosynthetic pigments were not affected by UV-B radiation. Water stress reduced photosynthetic pigments only under high UV-B radiation. The decrease was more accentuated for chlorophyll a than for chlorophyll b. As a measure for the maximum efficiency of photosystem II in darkness F (v)/F (m) was used, which was not affected by drought stress but initially reduced by UV-B radiation. Independent of water supply, UV-B radiation increased the activity of pirogalol peroxidase and did not increase the level of malondialdehyde. on the other hand, water stress did not alter the activity of pirogalol peroxidase and caused membrane damage as assessed by lipid peroxidation. The application of UV-B radiation together with drought seemed to have a protective effect by lowering the intensity of lipid peroxidation caused by water stress. The content of proline was not affected by UV-B radiation but was increased by water stress under both low and high UV-B radiation. After 24 h of rehydration, most of the parameters analyzed recovered to the same level as the unstressed plants.

Effect of biotic and abiotic factors on the tunneling behavior of Coptotermes gestroi and Heterotermes tenuis (Isoptera : Rhinotermitidae)

Using bidimensional arenas, the construction and spatial dispersion of tunnels constructed by Coptotermes gestroi and Heterotermes tenuis (Rhinotermitidae) was determined under different laboratory conditions. Workers of both species showed an increase of the tunneled area with the rise in temperature. The activity of workers of C gestroi also increased with the rise in soil moisture. Primary tunnels showed a high degree of dispersion in the arenas for all treatments. The presence of food did not influence the tunneling pattern of C. gestroi; but for H. tenuis there was a significant decrease in the number of tunnels. In addition, the type of substrate affected the tunneling pattern in both species. The understanding of food searching strategies of subterranean termites could contribute in the improvement of pest management programs based on the use of toxic baits. (c) 2005 Elsevier B.V. All rights reserved.

Serum melatonin level and oxidative stress in sickle cell anemia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Germination of Jacaranda mimosifolia (D. Don - Bignoniaceae) seeds: effects of light, temperature and water stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Noradrenergic response in vas deferens from rats submitted to acute and repeated stress

1. This work investigated the effects of androgens on the norepinephrine sensitivity of vasa deferentia from rats submitted to acute or repeated stress, as well as the participation of alpha(1)-adrenoceptors in the response of intact and bisected vasa deferentia from adult normal rats submitted to acute or repeated stress.2. The acute stress produced subsensitivity to norepinephrine only in intact vasa deferentia from adult normal rats, which was prevented by lack of androgens, suggesting that the sensitivity may be dependent on the physiological level of androgen,3. No change was observed in intact vas deferens sensitivity to norepinephrine in repeated stress, suggesting the occurrence of adaptation to elevated norepinephrine levels or a mild decrease in androgen levers or both.4. The changes in sensitivity observed in acute and repeated stress may also be due to alterations in alpha(1)-adrenergic receptors that are located in the prostatic portion of the vas deferens. (C) 1998 Elsevier B.V.

EFFECT OF DROUGHT AND DEFOLIATION STRESS IN THE FIELD ON SOYBEAN SEED-GERMINATION AND VIGOR

Although drought and defoliation stress have been shown to reduce soybean [Glycine max (L.). Merr.] yield, little information has been published regarding their effects on soybean seed quality. Field experiments were conducted in 1986, 1987, and 1989 to evaluate the effect of drought and defoliation (1989 only) stress during soybean seed development on seed germination and vigor. Essex (MG [maturity group] V) and Union (MG III) were grown in 1986 and 1987, and Harper (MG III) and McCall (MG 00) in 1989. Moisture treatments were either well watered or drought stressed during seed development (R5 to R7). In 1989, a total defoliation treatment was also imposed at R6 as an additional stress factor. There were significant reductions in yield and yield components following drought stress in all 3 yr and following defoliation in 1989. Leaf conductance and transpiration also decreased in the drought stress treatments. There was no effect of drought stress on seed germination or seed vigor as measured by accelerated aging germination and the cold test across the four cultivars (determinate and indeterminate) and 3 yr. In 1989 slight changes in 3-d germination and conductivity occurred for some drought stress treatments. Most of this response, however, was related to increased occurrence of hard seed, which does not represent an indication of a change in vigor. Seed germination and vigor were significantly reduced for small, flat, shriveled, and underdeveloped seeds that only occurred following defoliation. These seeds represented a small portion of the seed lot that would normally be removed during conditioning. The data suggest that drought stress would have no effect on seed germination or vigor, unless the stress was severe enough to produce shriveled, flat, underdeveloped seeds.