Disparate patterns of age-related changes in lipid peroxidation in long-lived naked mole-rats and shorter-lived mice

A key tenet of the oxidative stress theory of aging is that levels of accrued oxidative damage increase with age. Differences in damage generation and accumulation therefore may underlie the natural variation in species longevity. We compared age-related profiles of whole-organism lipid peroxidation (urinary isoprostanes) and liver lipid damage (malondialdehyde) in long living naked mole-rats [maximum lifespan (MLS) > 28.3 years] and shorter-living CB6F1 hybrid mice (MLS approximately 3.5 years). In addition, we compared age-associated changes in liver non-heme iron to assess how intracellular conditions, which may modulate oxidative processes, are affected by aging. Surprisingly, even at a young age, concentrations of both markers of lipid peroxidation, as well as of iron, were at least twofold (P < 0.005) greater in naked mole tats than in mice. This refutes the hypothesis that prolonged naked mole-rat longevity is due to superior protection against oxidative stress. The age-related profiles of all three parameters were distinctly species specific. Rates of lipid damage generation in mice were maintained throughout adulthood, while accrued damage in old animals was twice that of young mice. In naked mole-rats, urinary isoprostane excretion declined by half with age (P < 0.001), despite increases in tissue iron (P < 0.05). Contrary to the predictions of the oxidative stress theory, lipid damage levels did not change with age in mole-rats. These data suggest that the patterns of age-related changes in levels of markers of oxidative stress are species specific, and that the pronounced longevity of naked mole-rats is independent of oxidative stress parameters.     

Synergistic effect of conjugated linolenic acid isomers against induced oxidative stress,inflammation and erythrocyte membrane disintegrity in rat model

Background

α-Eleostearic acid and punicic acid, two typical conjugated linolenic acid (CLnA) isomers present in bitter gourd and snake gourd oil respectively, exhibit contrasting cis-trans configuration which made them biologically important.

Methods

Rats were divided into six groups. Group 1 was control and group 2 was treated control. Rats in the groups 3 and 4 were treated with mixture of α-eleostearic acid and punicic acid (1:1) (0.5% and 1.0% respectively) while rats in the groups 5 and 6 were treated with 0.5% of α-eleostearic acid and 0.5% of punicic acid respectively along with sodium arsenite by oral gavage once per day.

Results

Results showed that increase in nitric oxide synthase (NOS) activity, inflammatory markers expression, platelet aggregation, lipid peroxidation, protein oxidation, DNA damage and altered expression of liver X receptor-α (LXR-α) after arsenite treatment were restored with the supplementation of oils containing CLnA isomers. Altered activities of different antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and ferric reducing ability of plasma (FRAP) also restored after oil supplementation. Altered morphology and fluidity of erythrocyte membrane studied by atomic force and scanning electron microscopy, after stress induction were significantly improved due to amelioration in cholesterol/phospholipid ratio and fatty acid profile of membrane. Oils treatment also improved morphology of liver and fatty acid composition of hepatic lipid.

Conclusions

Overall two isomers showed synergistic antioxidant and anti-inflammatory effect against induced perturbations and membrane disintegrity.

General significance

Synergistic antioxidant and anti-inflammatory role of these CLnA isomers were established by this study.     

Cadmium tolerance and its phytoremediation by two oil yielding plants Ricinus communis (L.) and Brassica juncea (L.) from the contaminated soil

The effect of increasing level of cadmium in soil was investigated on biomass production, antioxidants, Cd bioaccumulation and translocation in Ricinus communis vis-à-vis a commonly studied oil crop Brassica juncea. The plants were exposed to 25, 50, 75, 100, and 150 mg Cd/Kg soil for up to 60 days. It was found that R. communis produced higher biomass at all the contamination levels than that of B. juncea. Proline and malondialdehyde in the leaves increased with increase in Cd level in both the species, whereas soluble protein decreased. The bioaccumulation of Cd was higher in B. juncea on the basis of the per unit biomass, total metal accumulation per plant was higher in R. communis. The translocation of Cdfrom roots to shoot was also higher in B. juncea at all Cd concentrations. R. communis appeared more tolerant and capable to clean Cd contaminated soil for longer period in one sowing than B. juncea and the former can grow in wasteland soil also in which later cannot be cultivated.     

Response of Spinach Leaves (Spinacia oleracea L.) to Ozone Measured by Gas Exchange,Chlorophyll a Fluorescence,Antioxidant Systems,and Lipid Peroxidation

Spinach (Spinacia oleracea L. cv. Clermont) leaves grown in open-top chambers and exposed to three different concentrations of ozone were measured for gas exchange, chlorophyll a fluorescence, antioxidant systems, and lipid peroxidation at the end of growing season. High O₃ concentration reduced F_v/F_m, indicating that the efficiency in the energy conversion of photosystem 2 (PS2) was altered. The rate of non-cyclic electron transport rate and the capacity to reduce the quinone pool were also affected. The development of non-photochemical quenching was not high enough to decrease the photon excess in the PS2. The limitation of photosynthetic activity was probably correlated with stomata closure and with an increase in intercellular CO₂ concentration. Under oxidative stress, superoxide dismutase (SOD) activity was stimulated in parallel with lipid peroxidation. We did not find any differences in the ascorbate (AsA) pool and ascorbate peroxidase (APX) or glutathione reductase (GR) activities between air qualities. Small, but similar responses were observed in spinach leaves exposed to ambient ozone concentration.     

卡巴胆碱对缺血再灌注大鼠小肠组织髓过氧化物酶的影响

研究拟胆碱药卡巴胆碱对大鼠缺血再灌注损伤小肠组织髓过氧化物酶 (MPO)和丙二醛 (MDA)的影响及其与肠损伤相关指标变化的规律。Wistar大鼠被随机分为预防、治疗和对照三组。活杀后取小肠组织测MPO、MDA和肿瘤坏死因子 (TNF-α)含量。结果显示 ,治疗组及预防组MPO活性、MDA和TNF -α含量均明显低于对照组 ,治疗组与预防组之间差异不明显。提示卡巴胆碱可抑制致炎因子TNF -α的释放 ,减少中性粒细胞在肠组织的聚集 ,从而使小肠MPO活性降低     

Hg~(2+)对苜蓿叶片的毒害效应

研究了Hg2 + 对苜蓿叶片的毒害效应。结果表明 :随着Hg2 + 浓度的增加和处理时间的延长 ,叶绿素含量下降 ,电导度上升 ;低Hg2 + 浓度及短时间处理 ,超氧阴离子自由基 (O·2 )和丙二醛 (MDA)含量增加 ,SOD、POD和CAT等保护酶活性升高 ,表明膜系统受到了伤害 ;高Hg2 +浓度及长时间处理 ,O·2 和MDA含量下降 ,SOD、POD和CAT等保护酶活性降低 ,表明细胞结构和功能受到了不可逆的伤害。     

Ethanol-induced hepatotoxicity and protective effect of betaine.

The protective effects of betaine in ethanol hepatotoxicity were investigated in 24 female wistar albino rats. Animals were divided into three groups: control, ethanol and ethanol + betaine group. Animals were fed liquid diets and consumed approximately 60 diet per day. Rats were fed ethanol 8 kg(- 1) day(- 1). The ethanol + betaine group were fed ethanol plus betaine (0.5% w/v). All animal were fed for 2 months. Reduced glutathione, malondialdehyde and vitamin A were determined in the liver tissue. Alanine aminotransferase activities were also measured on intracardiac blood samples. GSH levels in the ethanol group were significantly lower than these in the control group (p < 0.001). GSH was elevated in the betaine group as compared to the ethanol group (p < 0.001). MDA in the ethanol group was significantly higher than that in the control group (p < 0.05). MDA was decreased in the betaine group as compared to the ethanol group (p < 0.05). Vitamin A in the ethanol group was significantly lower than that in the control group (p < 0.01), but, in the ethanol + betaine group it was high compared with the ethanol group (p < 0.01). ALT in the ethanol group was higher than that in the control group (p < 0.05). Oxidative stress may play a major role in the ethanol-mediated hepatotoxicity. Betaine may protect liver against injury and it may prevent vitamin A depletion. Therefore, it may be a useful nutritional agent in the prevention of clinical problems dependent on ethanol-induced vitamin A depletion and peroxidative injury in liver.     

Doxorubicin-induced alterations in kidney functioning,oxidative stress,DNA damage,and renal tissue morphology; Improvement by Acacia hydaspica tannin-rich ethyl acetate fraction

Doxorubicin (DOX) is an anthracycline drug used for cancer treatment. However, its treatment is contiguous with toxic effects. We examined the nephroprotective potential of A. hydaspica polyphenol-rich ethyl acetate extract (AHE) against DOX persuaded nephrotoxicity. 36 male Sprague Dawley rats were randomly assorted into 6 groups. Control group received saline; DOX group: 3 mg/kg b.w. dosage of DOX intraperitoneally for 6 weeks (single dose/week). In co-treatment groups, 200 and 400 mg/kg b.w AHE was given orally for 6 weeks in concomitant with DOX (3 mg/kg b.w, i.p. injection per week) respectively. Standard group received silymarin 400 mg/kg b.w daily + DOX (single dose/week). Biochemical kidney function tests, oxidative stress markers, genotoxicity, antioxidant enzyme status, and histopathological changes were examined. DOX caused significant body weight loss and decrease kidney weight. DOX-induced marked deterioration in renal function indicators in both urine and serum, i.e., PH, specific gravity, total protein, albumin, urea, creatinine, uric acid, globulin, blood urea nitrogen, etc. Also, DOX treatment increases renal tissue oxidative stress markers, while lower antioxidant enzymes in tissue along with degenerative alterations in the renal tissue compared to control rats. AHE co-treatment ameliorates DOX-prompted changes in serum and urine chemistry. Likewise, AHE treatment decreases sensitive markers of oxidative stress and prevented DNA damages by enhancing antioxidant enzyme levels. DOX induction in rats also caused DNA fragmentation which was restored by AHE co-treatment. Moreover, the histological observations evidenced that AHE effectively rescued the kidney tissue from DOX interceded oxidative damage. Our results suggest that co-treatment of AHE markedly improve DOX-induced deleterious effects in a dose-dependent manner. The potency of AHE co-treatment at 400 mg/kg dose is similar to silymarin. These outcomes revealed that A. hydaspica AHE extract might serve as a potential adjuvant that avoids DOX-induced nephrotoxicity.     

Evaluation of the antiparasitic activity of the chitosan-silver nanocomposites in the treatment of experimentally infested pigeons with Pseudolynchia canariensis

This study aimed to evaluate the efficacy of chitosan-silver nanocomposites in the treatment of experimentally infested pigeons with Pseudolynchia canariensis (P. canariensis) with evaluation of different immunological parameters before and after treatment. Therefore, fourteen birds were divided into 2 groups; group1(infested group including 12 birds) which subdivided into 6 sub-groups experimentally infested pigeons 2 pigeons each, and five group of them were treated with chitosan-silver nanocomposites and sub-group number 6 was treated with deltamethrin while, group 2 including two pigeons were kept as control negative ones. P. canariensis flies distributed under the wing and /or under the tail in infested group and these pigeons showed significantly lower RBCs and higher WBCs than that in non-infested pigeons. The cell mediated immune response against experimentally infested pigeons with P. canariensis was studied. P. canariensis infestation in pigeons have a negative impact on pigeon’s blood parameters, increase TNF-α and IL-1β cytokines levels. This study cleared out the role of P. canariensis in the induction of a case of oxidative stress indicated by high level of nitric oxide and malondialdehyde (MDA) with low antioxidant capacity in shape of reduced zinc concentration in the sera of experimentally infested pigeon. Chitosan-silver nanocomposite has a promising effect in the elimination of P. canariensis infestation in pigeons.