Critical evaluation of the free radical theory of aging. A proposal for the oxidative stress hypothesis

Mitochondrial redox state, bioenergetics, and calcium transport in caloric restriction: A metabolic nexus

Mitochondria congregate central reactions in energy metabolism, many of which involve electron transfer. As such, they are expected to both respond to changes in nutrient supply and demand and also provide signals that integrate energy metabolism intracellularly. In this review, we discuss how mitochondrial bioenergetics and reactive oxygen species production is impacted by dietary interventions that change nutrient availability and impact on aging, such as calorie restriction. We also discuss how dietary interventions alter mitochondrial Ca2+ transport, regulating both mitochondrial and cytosolic processes modulated by this ion. Overall, a plethora of literature data support the idea that mitochondrial oxidants and calcium transport act as integrating signals coordinating the response to changes in nutritional supply and demand in cells, tissues, and animals.

Oxidative stress, inflammation and hormesis: The role of dietary and lifestyle modifications on aging

Oxidative stress (OS) is primarily caused by the formation of free radicals and reactive oxygen species; it is considered as one of the prominent factors in slowing down and degrading cellular machinery of an individual, and it eventually leads to aging and age-related diseases by its continuous higher state. The relation between molecular damage and OS should be particularized to understand the beginning of destruction at the cellular levels, extending outwards to affect tissues, organs, and ultimately to the organism. Several OS biomarkers, which are established at the biomolecular level, are useful in investigating the disease susceptibility during aging. Slowing down the aging process is a matter of reducing the rate of oxidative damage to the cellular machinery over time. The breakdown of homeostasis, the mild overcompensation, the reestablishment of homeostasis, and the adaptive nature of the process are the essential features of hormesis, which incorporates several factors, including calorie restriction, nutrition and lifestyle modifications that play an important role in reducing the OS. In the current review, along with the concept and theories of aging (with emphasis on free radical theory), various manifestations of OS with special attention on mitochondrial dysfunction and age-related diseases have been discussed. To alleviate the OS, hormetic approaches including caloric restriction, exercise, and nutrition have also been discussed.

Heliconia rostrata rhizomes mitigate chemical-induced liver injury by debilitating oxidative stress in HepG2 cells and rats

ETHNOPHARMACOLOGICAL RELEVANCE

Heliconia rostrata Ruiz and Pav. belongs to the family Heliconiaceae. Plant was traditionally used to cure jaundice, intestinal pain, diabetes and hypertension.

AIM OF THE EXPERIMENT

Present study evaluated hepatoprotective efficacy of ethanol (REE) and methanol (RME) extracts of H. rostrata rhizomes in HepG2 cell lines and rats. Antioxidant efficacy of extracts was determined using ex vivo and in vivo methods.

MATERIALS AND METHODS

Before conducting efficacy studies, safety of REE and RME was established using toxicity studies which included Oral acute-fixed dose toxicity using OECD TG420, 28-days repeated dose oral toxicity by OECD TG407 and cytotoxicity studies by brine shrimp lethality (BSL) bioassay and MTT assay taking HepG2 cell line. Ex vivo (Extracts: 0-250 μg/ml) and in vivo (Extracts: 50, 100 and 200 mg/kg) antioxidant studies were performed on fresh goat liver and rats (N = 45) of either sex, respectively. In vitro hepatoprotective efficacy of extracts was evaluated against ethanol induced toxicity in HepG2 cell line. In vivo study was performed at 50, 100 and 200 mg/kg/day doses in rats by CCl₄-induced hepatotoxicity study.

RESULTS

No mortality was observed during single and repeated dose toxicity studies. 50% lethal dose >2000 mg/kg, confirmed category 5 toxicity level of extracts, according to Globally Harmonized System. No signs of toxicity and treatment or dose related changes recorded in rats under repeated dose toxicity study. No-observed-adverse effect-level of 200 mg/kg/day was observed for both extracts. Median lethal concentration of REE and RME were 1291.30 and 1045.89 μg/ml, respectively in BSL bioassay and 50% cytotoxicity concentration >1000 μg/ml was obtained for both extracts from MTT assay. Calculated 50% inhibitory concentration and median effective dose of extracts obtained from different antioxidant assays in ex vivo and in vivo antioxidant studies, respectively indicated REE has more antioxidant efficacy than RME. In in vitro hepatoprotective efficacy study, extracts demonstrated dose dependent protection against ethanol induced hepatotoxicity. At 400 μg/ml, REE and RME demonstrated percentage protection of 65.53% and 57.98%, respectively. Results of liver function test and histopathological evaluation of liver in in vivo hepatoprotective study confirmed dose dependent protection provided by the extracts against CCl₄ -induced hepatotoxicity.

CONCLUSION

Both REE and RME were found safe to be considered for therapeutic uses. Both REE and RME were found to exhibit antioxidant efficacy in ex vivo and in vivo models. Results ascertained that H. rostrata rhizomes possess significant hepatoprotective potency.

Effects of titanium with different micro/nano structures on the ability of osteoblasts to resist oxidative stress

Excessive accumulation of oxidative intermediates in the elderly significantly aggravates bone degradation and hinders the osseointegration of topological titanium (Ti) implants. Thus, it is of great significance to evaluate the antioxidant and osteoinduction capabilities of various nano, micro or micro/nano-composite structures under oxidative stress (OS) microenvironment. In this study, we discovered that 110 nm titania nanotubes (TNTs) enhanced the adsorption of fibronectin (FN) proteins onto smooth and rough titanium surfaces to varying degrees. Compared with Ti and 30 nm TNTs (T₃₀) groups, cells on 110 nm TNTs (T₁₁₀), microstructure/30 nm TNTs (M₃₀) and microstructure/110 nm TNTs (M₁₁₀) had smaller area, lower reactive oxygen species (ROS), and better proliferation/osteogenic differentiation abilities under OS condition, but there was no significant difference among the three groups. In addition, combined with our previous study, we suggested that T₁₁₀, M₃₀ and M₁₁₀ resistance to OS was also strongly associated with the high expression of FN-receptor integrin α5 or β1. All the findings indicated that the micro/nano-composed structures (M₃₀ & M₁₁₀) had similar anti-oxidation and osteogenesis abilities to T₁₁₀, which provided guidance for the application of different titanium implants with different topologies in the elderly.

Design, synthesis, molecular modelling and biological evaluation of novel 3-(2-naphthyl)-1-phenyl-1H-pyrazole derivatives as potent antioxidants and 15-Lipoxygenase inhibitors

Oxidative stress is one of the main causes of significant severe diseases. The discovery of new potent antioxidants with high efficiency and low toxicity is a great demand in the field of medicinal chemistry. Herein, we report the design, synthesis molecular modelling and biological evaluation of novel hybrids containing pyrazole, naphthalene and pyrazoline/isoxazoline moiety. Chalcones 2a–e were synthesized efficiently and were used as starting materials for synthesis of a variety of heterocycles. A novel series of pyrazoline 3a–e, phenylpyrazoline 4a–e, isoxazoline 5a–e and pyrazoline carbothioamide derivatives 6a–e were synthesized and screened for in vitro antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and superoxide radical scavenging assay as well as 15-lipoxygenase (15-LOX) inhibition activity. Compounds 3a, 4e, 5b, 5c, 6a, 6c, and 6e showed excellent radical scavenging activity in all three methods in comparison with ascorbic acid and 15-LOX inhibition potency using quercetin as standard then were subjected to in vivo study. Catalase (CAT) activity, glutathione (GSH) and malondialdehyde (MDA) levels were assayed in liver of treated rats. Compounds 5b, 5c, and 6e showed significant in vivo antioxidant potentials compared to control group at dose of 100 mg/kg B.W. Molecular docking of compound 6a endorsed its proper binding at the active site pocket of the human 15-LOX which explains its potent antioxidant activity in comparison with standard ascorbic acid.

Impact of Lactobacillus plantarum 423 fermentation on the antioxidant activity and flavor properties of rice bran and wheat bran

Rice bran (RB) and wheat bran (WB) fermented with L. plantarum 423 had enhanced odor intensity, especially for sulfides and aromatics. The hydroxyl radical-scavenging activity (73.28 ± 3.18%) and oxygen radical-scavenging activity (2.12 ± 0.08 mmol·TE/g) of RB fermentation broth were better than those of WB fermentation broth. Even at 2 μg/ml, the purified antioxidant fractions from the WB fermentation broth showed strong intracellular ROS-scavenging activity in human umbilical vein endothelial cells (HUVECs), and the purified antioxidant fractions (200 μg/ml) from the RB fermentation broth had a good antiaging effect. The dominant antioxidant components in the RB and WB fermentation broths were acids (70.21%) and ketones (10.64%), these components jointly give the RB and WB fermentation broths a variety of antioxidant properties. These results are beneficial for developing RB and WB deep-processing technology and laid the foundation for the preparation of antioxidant fractions with L. plantarum 423.

Antioxidants and antioxidant methods: an updated overview

Antioxidants had a growing interest owing to their protective roles in food and pharmaceutical products against oxidative deterioration and in the body and against oxidative stress-mediated pathological processes. Screening of antioxidant properties of plants and plant-derived compounds requires appropriate methods, which address the mechanism of antioxidant activity and focus on the kinetics of the reactions including the antioxidants. Many studies evaluating the antioxidant activity of various samples of research interest using different methods in food and human health have been conducted. These methods are classified, described, and discussed in this review. Methods based on inhibited autoxidation are the most suited for termination-enhancing antioxidants and for chain-breaking antioxidants, while different specific studies are needed for preventive antioxidants. For this purpose, the most common methods used in vitro determination of antioxidant capacity of food constituents were examined. Also, a selection of chemical testing methods was critically reviewed and highlighted. In addition, their advantages, disadvantages, limitations and usefulness were discussed and investigated for pure molecules and raw extracts. The effect and influence of the reaction medium on the performance of antioxidants are also addressed. Hence, this overview provides a basis and rationale for developing standardized antioxidant methods for the food, nutraceuticals, and dietary supplement industries. In addition, the most important advantages and shortcomings of each method were detected and highlighted. The chemical principles of these methods are outlined and critically discussed. The chemical principles of methods of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS^·+) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging, Fe³⁺-Fe²⁺ transformation assay, ferric reducing antioxidant power (FRAP) assay, cupric ions (Cu²⁺) reducing power assay (Cuprac), Folin-Ciocalteu reducing capacity (FCR assay), peroxyl radical (ROO·), superoxide radical anion (O₂^·-), hydrogen peroxide (H₂O₂) scavenging assay, hydroxyl radical (OH·) scavenging assay, singlet oxygen (¹O₂) quenching assay, nitric oxide radical (NO·) scavenging assay and chemiluminescence assay are outlined and critically discussed. Also, the general antioxidant aspects of main food components were discussed by a number of methods, which are currently used for the detection of antioxidant properties of food components. This review consists of two main sections. The first section is devoted to the main components in the food and pharmaceutical applications. The second general section comprises some definitions of the main antioxidant methods commonly used for the determination of the antioxidant activity of components. In addition, some chemical, mechanistic and kinetic basis, and technical details of the used methods are given.

Modulation of senoinflammation by calorie restriction based on biochemical and Omics big data analysis

Aging is a complex and progressive process characterized by physiological and functional decline with time that increases susceptibility to diseases. Aged-related functional change is accompanied by a low-grade, unresolved chronic inflammation as a major underlying mechanism. In order to explain aging in the context of chronic inflammation, a new integrative concept on age-related chronic inflammation is necessary that encompasses much broader and wider characteristics of cells, tissues, organs, systems, and interactions between immune and non-immune cells, metabolic and non-metabolic organs. We have previously proposed a novel concept of senescent (seno)-inflammation and provided its frameworks. This review summarizes senoinflammation concept and additionally elaborates modulation of senoinflammation by calorie restriction (CR). Based on aging and CR studies and systems-biological analysis of Omics big data, we observed that senescence associated secretory phenotype (SASP) primarily composed of cytokines and chemokines was notably upregulated during aging whereas CR suppressed them. This result further strengthens the novel concept of senoinflammation in aging process. Collectively, such evidence of senoinflammation and modulatory role of CR provide insights into aging mechanism and potential interventions, thereby promoting healthy longevity. [BMB Reports 2019; 52(1): 56-63].

Isoflavones prevent oxidative stress and inhibit the activity of the enzyme monoamine oxidase in vitro

Oxidative stress occurs due to an imbalance between antioxidant defenses and pro-oxidant agents in brain. This condition has been associated to the pathogenesis of several brain diseases; therefore, increasing the use of compounds that exert antioxidant activity. Thus, the objective of this study was to evaluate, in vitro, the effect of isoflavones in: (1) lipid peroxidation, catalase activity and thiol groups in the presence of pro-oxidants: sodium nitroprusside or Fe²⁺/EDTA complex in rat brain homogenates; (2) the activity of the enzyme monoamine oxidase (MAO). As a result, the isoflavones reduced lipid peroxidation in a manner dependent on the concentration and protected against the reduction of catalase activity as well as the induced thiol oxidation in brain tissue. In addition, isoflavones inhibited MAO activity (MAO-A and MAO-B). Taken together, our results showed that isoflavones avoided oxidative stress and decreased the MAO activity, suggesting a promissory use in the treatment of neurodegenerative diseases.

Ginkgo biloba Extract Protects Mesenteric Arterioles of Old Rats via Improving Vessel Elasticity through Akt/FoxO3a Signaling Pathway

BACKGROUND

Previous studies have shown that Ginkgo biloba extract (GBE) dietary diminished salt-related elevation of blood pressure and ameliorated ischemic diseases. However, whether GBE could improve vascular elasticity to protect mesenteric arterioles of old rats is still elusive. In this study, we aimed to investigate the effects of GBE on vascular elasticity of old rats and its possible underlying mechanism.

METHODS

Morphological changes of mesenteric arterioles were observed using hematoxylin and eosin and Verhoeff-Van Gieson staining, and diameters of mesenteric arterioles under various pressure were detected after GBE administration. In addition, phosphorylation level of Akt and FoxO3a proteins from mesenteric arterioles were detected.

RESULTS

The results implicated that GBE treatment narrowed endothelial cell gap and increased the curvature of inner elastic membrane with reduced middle layer collagen fiber. Meanwhile, compared with young rats, old rats appeared to have lower vascular elasticity while GBE treatment at 50, 100, and 200 mg/kg dosage through intragastric administration per day for 3 weeks could effectively improve the vascular elasticity under different pressures in a dose-dependent manner. Furthermore, phosphorylation level of Akt and FoxO3a was also reduced in GBE-treated rats.

CONCLUSIONS

This is the first report to indicate that GBE might exert protective effect on mesenteric arterioles of old rats via improving vascular elasticity and Akt/FoxO3a signaling pathway might be involved in this action.

Modulation of senoinflammation by calorie restriction based on biochemical and Omics big data analysis

Aging is a complex and progressive process characterized by physiological and functional decline with time that increases susceptibility to diseases. Aged-related functional change is accompanied by a low-grade, unresolved chronic inflammation as a major underlying mechanism. In order to explain aging in the context of chronic inflammation, a new integrative concept on age-related chronic inflammation is necessary that encompasses much broader and wider characteristics of cells, tissues, organs, systems, and interactions between immune and non-immune cells, metabolic and non-metabolic organs. We have previously proposed a novel concept of senescent (seno)-inflammation and provided its frameworks. This review summarizes senoinflammation concept and additionally elaborates modulation of senoinflammation by calorie restriction (CR). Based on aging and CR studies and systems-biological analysis of Omics big data, we observed that senescence associated secretory phenotype (SASP) primarily composed of cytokines and chemokines was notably upregulated during aging whereas CR suppressed them. This result further strengthens the novel concept of senoinflammation in aging process. Collectively, such evidence of senoinflammation and modulatory role of CR provide insights into aging mechanism and potential interventions, thereby promoting healthy longevity. [BMB Reports 2019; 52(1): 56-63].

Levels of circulating cortisol and cytokines in members of the Canadian Armed Forces: associations with age, sex, and anthropometry

This study assessed blood levels of cortisol and cytokines (inflammatory and non-inflammatory) in members of the regular Canadian Armed Forces (CAF), and examined the associations between sex, age, and adiposity and circulating levels of cortisol as well as pro- and anti-inflammatory cytokines. As part of a larger ranging project, 331 blood samples were collected from a representative population of the total CAF, which included officers and noncommissioned women and men from the Air Force, Navy, and Army. The blood samples were analyzed for levels of cortisol, C-reactive protein (CRP), adiponectin, and 20 cytokines (which included interleukins, interferons, and tumor necrosis factors). Higher levels of adiponectin were found in women compared with men (median and interquartile range; 16.71 (7.68-25.32) vs 5.81 (3.52-13.19) μg/mL), and higher levels of interleukin (IL)-18 in men compared with women (89.25 (84.03-94.48) vs 75.91 (69.70-82.13) pg/mL). An association between age and levels of stress and inflammatory cytokines was observed, with CRP, IL-18, IL-2 and adiponectin all increasing with increasing age. However, contrary to trends seen in the general population, cortisol levels decreased with increasing age. Levels of CRP and IL-18 increased with an increase in adiposity, while adiponectin levels decreased. Most importantly, at the entire cohort level, a low detection rate for most of the cytokines was observed with 17 out of 22 cytokines having a detection below 10%.

IN CONCLUSION

In this CAF population, although an association between age and inflammatory cytokines was observed, both sex and adiposity had a small impact on levels of cortisol and cytokines.

Scientific evidence for therapeutic effects of Chinese prescription Kangen-karyu from pre-clinical animal experiments

Chinese prescription Kangen-karyu, comprised of six crude drugs, has received much attention due to its numerous biological activities. The present study reports therapeutic evidence for Kangen-karyu from pre-clinical animal experiments related to human diseases. Kangen-karyu showed beneficial effects on type 1 diabetes and related complications through the suppression of protein expression related to advanced glycation endproducts and oxidative stress. Kangen-karyu reduced oxidative stress via the regulation of dyslipidemia, and also exerted a renoprotective effect mainly through its antioxidant properties during the development of diabetic nephropathy in type 2 diabetes. In addition, Kangen-karyu showed neuroprotective effects by attenuating the spatial memory impairment and neuronal death induced by diabetes. Kangen-karyu counteracted oxidative stress and ameliorated tissue damage possibly associated with aging. These findings provide scientific evidence to explain the efficacy of Kangen-karyu based on its underlying therapeutic effects.

Short-term calorie restriction ameliorates genomewide, age-related alterations in DNA methylation

DNA methylation plays major roles in many biological processes, including aging, carcinogenesis, and development. Analyses of DNA methylation using next-generation sequencing offer a new way to profile and compare methylomes across the genome in the context of aging. We explored genomewide DNA methylation and the effects of short-term calorie restriction (CR) on the methylome of aged rat kidney. Whole-genome methylation of kidney in young (6 months old), old (25 months old), and OCR (old with 4-week, short-term CR) rats was analyzed by methylated DNA immunoprecipitation and next-generation sequencing (MeDIP-Seq). CpG islands and repetitive regions were hypomethylated, but 5'-UTR, exon, and 3'-UTR hypermethylated in old and OCR rats. The methylation in the promoter and intron regions was decreased in old rats, but increased in OCR rats. Pathway enrichment analysis showed that the hypermethylated promoters in old rats were associated with degenerative phenotypes such as cancer and diabetes. The hypomethylated promoters in old rats related significantly to the chemokine signaling pathway. However, the pathways significantly enriched in old rats were not observed from the differentially methylated promoters in OCR rats. Thus, these findings suggest that short-term CR could partially ameliorate age-related methylation changes in promoters in old rats. From the epigenomic data, we propose that the hypermethylation found in the promoter regions of disease-related genes during aging may indicate increases in susceptibility to age-related diseases. Therefore, the CR-induced epigenetic changes that ameliorate age-dependent aberrant methylation may be important to CR's health- and life-prolonging effects.

Anti-inflammaging effects of Lactobacillus brevis OW38 in aged mice

In the present study, lactic acid bacteria (LAB) strains were collected from kimchi and were screened to isolate strains that inhibit lipopolysaccharide (LPS) production by Escherichia coli and p16 expression and nuclear factor-kappa B (NF-κB) activation in LPS-stimulated macrophages. Oral administration of Lactobacillus brevis OW38 (1×109 cfu/mouse) to aged mice (male, 18 months old) for 8 weeks reduced the LPS level in colon fluid and blood. In addition, OW38 treatment also reduced the ratio of Firmicutes or Proteobacteria to Bacteroidetes, which was significantly higher in aged mice than in young mice. Treatment with OW38 in aged mice inhibited the expression of inflammatory markers, such as myeloperoxidase, tumour necrosis factor (TNF), and interleukin (IL)-1β, and inhibited NF-κB activation. Furthermore, it induced the expression of colonic tight junction proteins zonula occludens-1, occludin, and claudin-1. OW38 treatment also suppressed the expression of senescence markers p16, p53, and SAMHD1 in the colon and the hippocampus of aged mice. In addition, it significantly restored spontaneous alternation as well as the expression of brain-derived neurotrophic factor and doublecortin in aged mice compared to that in young mice (P<0.05). Based on these findings, we conclude that OW38 treatment may ameliorate aging-associated colitis and memory impairment by inhibiting gut microbiota LPS production, NF-κB activation, and p16 expression.

Neuroprotective efficacy of hesperetin against cadmium induced oxidative stress in the brain of rats

The present study was designed to investigate the neuroprotective effect of hesperetin (Hp) against cadmium (Cd)-induced neurotoxicity in rats. Cadmium (3 mg/kg body weight (b.w.), subcutaneous) administration for 3 weeks demonstrated neurotoxicity in rats by the decreased activity of acetylcholinesterase in the brain. The oxidative stress markers (thiobarbituric acid reactive substances and protein carbonyls) were significantly increased with decreased enzymatic (superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase) and non-enzymatic antioxidants (reduced glutathione, total sulphydryl groups and vitamin C). The proteolytic and membrane-bound enzymes (Na⁺ K⁺-ATPase, Mg²⁺-ATPase and Ca²⁺-ATPase) were also decreased with increased apoptotic markers (Bcl2 Associated X Protein (Bax), cytochrome C, caspase 3 and 9) and decreased anti-apoptotic marker (B-cell lymphoma 2 (Bcl2)) in the brain of Cd-treated rats. Moreover, Cd administration significantly decreased the mitochondrial electron transport chain complexes (I, II, III and IV) in the brain of rats. Preadministration of Hp (40 mg/kg b.w., oral) significantly attenuated the Cd-induced oxidative stress and mitochondrial dysfunction, restored the antioxidant and membrane-bound enzyme activities and decreased apoptosis in the brain of rats.

The Greenland shark: A new challenge for the oxidative stress theory of ageing?

The free radical theory of ageing predicts that long-lived species should be more resistant to oxidative damage than short-lived species. Although many studies support this theory, recent studies found notable exceptions that challenge the generality of this theory. In this study, we have analysed the oxidative status of the Greenland shark (Somniosus microcephalus), which has recently been found as the longest living vertebrate animal known to science with a lifespan of at least 272years. As compared to other species, the Greenland shark had body mass-corrected values of muscle glutathione peroxidase and red blood cells protein carbonyls (metric of protein oxidative damage) above 75 percentile and below 25 percentile, respectively. None of the biochemical metrics of oxidative status measured in either skeletal muscle or red blood cells were correlated with maximum lifespan of species. We propose that the values of metrics of oxidative status we measured might be linked to ecological features (e.g., adaptation to cold waters and deep dives) of this shark species rather to its lifespan.

Biomarkers of skin aging

Aging is a complex process not only influenced by inherited but also by several environmental factors. It is characterized by a progressive loss of function in multiple tissues, which leads to an increased probability of death. On the other hand, several morphological and histological changes are registered in aged skin that is mostly dependent on the cumulative exposure in environmental aging promoters, such as ultraviolet radiation. Understanding of individual pathogenesis and introduction of preventive measurements require objective assessment, i.e., the administration of biomarkers. Because of the complexity of skin aging, the exact definition of biomarkers is a major research challenge. In this article, we summarize the basic knowledge involving skin aging and its biomarkers.

DADS Analogues Ameliorated the Cognitive Impairments of Alzheimer-Like Rat Model Induced by Scopolamine

The development of agents that affect two or more relevant targets has drawn considerable attention in treatment of AD. Diallyl disulfide (DADS), an active principle of garlic, has been reported to prevent APP processing by amyloidogenic pathway. Recently, we have reported a new series of DADS derivatives and our findings revealed that compound 7k and 7l could provide good templates for developing new multifunctional agents for AD treatment. Thus, the present study was constructed to investigate the neuroprotective effect of DADS analogues (7k and 7l) against Aβ-induced neurotoxicity in SH-SY5Y human neuroblastoma cells and in ameliorating the cognition deficit induced by scopolamine in rat model. The results indicated that compound 7k and 7l significantly inhibited Aβ1-42-induced neuronal cell death by inhibiting ROS generation. Moreover, they prevented apoptosis, in response to ROS, by restoring normal Bax/Bcl-2 ratio. Furthermore, it was observed that scopolamine-induced memory impairment was coupled by alterations in neurotransmitters, acetylcholinesterase activity and oxidative stress markers. Histological analysis revealed severe damaging effects of scopolamine on the structure of cerebral cortex and hippocampus. Administration of compounds 7k and 7l at 5 mg/kg significantly reversed scopolamine-induced behavioural, biochemical, neurochemical and histological changes in a manner comparable to standard donepezil. Together the present findings and previous studies indicate that compounds 7k and 7l have neuroprotective and cognition-enhancing effects, which makes them a promising multi-target candidate for addressing the complex nature of AD.

Hypertension and aging

Hypertension is a highly prevalent condition with numerous health risks, and the incidence of hypertension is greatest among older adults. Traditional discussions of hypertension have largely focused on the risks for cardiovascular disease and associated events. However, there are a number of collateral effects, including risks for dementia, physical disability, and falls/fractures which are increasingly garnering attention in the hypertension literature. Several key mechanisms--including inflammation, oxidative stress, and endothelial dysfunction--are common to biologic aging and hypertension development and appear to have key mechanistic roles in the development of the cardiovascular and collateral risks of late-life hypertension. The objective of the present review is to highlight the multi-dimensional risks of hypertension among older adults and discuss potential strategies for treatment and future areas of research for improving overall care for older adults with hypertension.

In vitro and In vivo Antioxidant Evaluation and Estimation of Total Phenolic, Flavonoidal Content of Mimosa pudica L

OBJECTIVE

Mimosa pudica Linn. (Mimosaceae) is traditionally used as a folk medicine to treat various ailments including convulsions, alopecia, diarrhea, dysentery, insomnia, tumor, wound healing, snake bite, etc., Here, the study was aimed to evaluate the antioxidant potential of M. pudica leaves extract against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) (in vitro) and its modulatory effect on rat brain enzymes.

MATERIALS AND METHODS

Total phenolic, flavonoid contents, and in vitro antioxidant potential against DPPH radical were evaluated from various extracts of M. pudica leaves. In addition, ethyl acetate extract of Mimosa pudica leaves (EAMP) in doses of 100, 200, and 400 mg/kg/day were administered orally for 7 consecutive days to albino rats and evaluated for the oxidative stress markers as thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) from rat brain homogenate.

RESULTS

The ethyl acetate extract showed the highest total phenolic content and total flavonoid content among other extracts of M. pudica leaves. The percentage inhibition and IC50 value of all the extracts were followed dose-dependency and found significant (P < 0.01) as compared to standard (ascorbic acid). The oxidative stress markers as SOD, CAT, and GSH were increased significantly (P < 0.01) at 200 and 400 mg/kg of EAMP treated animals and decreased significantly the TBARS level at 400 mg/kg of EAMP as compared to control group.

CONCLUSION

These results revealed that the ethyl acetate extract of M. pudica exhibits both in vitro antioxidant activity against DPPH and in vivo antioxidant activity by modulating brain enzymes in the rat. This could be further correlated with its potential to neuroprotective activity due to the presence of flavonoids and phenolic contents in the extract.

SUMMARY

Total phenolic, flavonoid contents and in-vitro antioxidant potential were evaluated from various extracts of M. pudica leaves. Again, in-vivo antioxidant evaluation from brain homogenate on oxidative stress markers as TBARS, SOD, CAT and GSH from rat was investigated. Our findings revealed that M. pudica possesses both in-vitro and in-vivo antioxidant activity due to presence of phenolics and flavonoids.

Luteolin-induced protection of H₂O₂-induced apoptosis in PC12 cells and the associated pathway

Increasing evidence has indicated that the generation of reactive oxygen species (ROS) contributes to H2O2‑induced nerve injury. This may result in oxidative stress that leads to cell damage or death. Dietary or pharmaceutical augmentation of the endogenous antioxidant defense capacity is a potential means by which to prevent ROS‑induced damage. The aim of the current study was to investigate the effect of luteolin on H2O2‑induced cell apoptosis in cultured rat pheochromocytoma cells (PC12 cells) and to investigate the role of the phosphatidylinositol‑3‑kinase (PI3K)/protein kinase B (Akt) pathway on H2O2‑induced apoptosis. The results demonstrated that luteolin was able to inhibit the reduction in cell viability induced by H2O2. In addition, luteolin reduced ROS generation and lactate dehydrogenase release in H2O2‑treated PC12 cells. The levels of superoxide dismutase and glutathione peroxidase activity were increased following treatment with luteolin, however malondialdehyde levels were observed to be reduced. Additionally, luteolin increased the Bcl‑2/Bax ratio and enhanced Akt phosphorylation. However, these alterations were attenuated by pretreatment with an inhibitor of the PI3K/Akt pathway. In conclusion, luteolin inhibited H2O2‑induced apoptosis via reducing ROS levels and activating the PI3K/Akt pathway.

Parkinson's disease as a result of aging

It is generally considered that Parkinson's disease is induced by specific agents that degenerate a clearly defined population of dopaminergic neurons. Data commented in this review suggest that this assumption is not as clear as is often thought and that aging may be critical for Parkinson's disease. Neurons degenerating in Parkinson's disease also degenerate in normal aging, and the different agents involved in the etiology of this illness are also involved in aging. Senescence is a wider phenomenon affecting cells all over the body, whereas Parkinson's disease seems to be restricted to certain brain centers and cell populations. However, reviewed data suggest that Parkinson's disease may be a local expression of aging on cell populations which, by their characteristics (high number of synaptic terminals and mitochondria, unmyelinated axons, etc.), are highly vulnerable to the agents promoting aging. The development of new knowledge about Parkinson's disease could be accelerated if the research on aging and Parkinson's disease were planned together, and the perspective provided by gerontology gains relevance in this field.

The probiotic mixture IRT5 ameliorates age-dependent colitis in rats

To investigate the anti-inflammatory effect of probiotics, we orally administered IRT5 (1×10(9)CFU/rat) for 8 weeks to aged (16 months-old) Fischer 344 rats, and measured parameters of colitis. The expression levels of the inflammatory markers' inducible NO synthase (iNOS), cyclooxygenase-2 (COX2), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were higher in the colons of normal aged rats (18 months-old) than in the colons of normal young rats (6 months-old). Treatment with IRT5 suppressed the age-associated increased expression of iNOS, COX2, TNF-α, and IL-1β, and activation of NF-κB and mitogen-activated protein kinases. In a similar manner, the expression of tight junction proteins in the colon of normal aged rats was suppressed more potently than in normal young rats, and treatment of aged rats with IRT5 decreased the age-dependent suppression of tight junction proteins ZO-1, occludin, and claudin-1. Treatment with IRT5 suppressed age-associated increases in expressions of senescence markers p16 and p53 in the colon of aged rats, but increased age-suppressed expression of SIRT1. However, treatment with IRT5 inhibited age-associated increased myeloperoxidase activity in the colon. In addition, treatment with IRT5 lowered the levels of LPS in intestinal fluid and blood of aged rats, as well as the reduced concentrations of reactive oxygen species, malondialdehyde, and C-reactive protein in the blood. These findings suggest that IRT5 treatment may suppress age-dependent colitis by inhibiting gut microbiota LPS production.

Orally administrated Lactobacillus pentosus var. plantarum C29 ameliorates age-dependent colitis by inhibiting the nuclear factor-kappa B signaling pathway via the regulation of lipopolysaccharide production by gut microbiota

To evaluate the anti-inflammaging effect of lactic acid bacteria (LAB) on age-dependent inflammation, we first screened and selected a tumor necrosis factor (TNF)-α and reactive oxygen species (ROS)-inhibitory LAB, Lactobacillus pentosus var. plantarum C29, among the LABs isolated from fermented vegetables using LPS-stimulated mouse peritoneal macrophages. Oral administration of C29 (2 × 109 CFU/rat) for 8 weeks in aged Fischer 344 rats (age, 16 months) inhibited the expression of the inflammatory markers myeloperoxidase, inducible nitric oxide (NO) synthase, cyclooxygenase-2, pro-inflammatory cytokines tumor necrosis factor (TNF)-α and IL-6 and the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), activator protein 1 (AP1), and mitogen-activated protein kinases (MAPKs). Treatment with C29 induced the expression of tight junction proteins ZO-1, occludin, and claudin-1, and reduced intestinal microbial LPS and plasmatic LPS levels and ROS, as well as the Firmicutes to Bacteroidetes ratio, which is significantly higher in aged rats than in young rats. C29 treatment also reduced plasmatic reactive oxygen species, malondialdehyde, C-reactive protein, and TNF-α, and suppressed expression of senescence markers p16 and p53 in the colon of the aged rats, but increased SIRT 1 expression. Based on these findings, we concluded that C29 treatment may suppress aging-dependent colitis by inhibiting NF-κB, AP1, and MAPK activation via the inhibition of gut microbiota LPS production and the induction of tight junction protein expression.

Chinese Prescription Kangen-karyu and Salviae Miltiorrhizae Radix Improve Age-Related Oxidative Stress and Inflammatory Response through the PI3K/Akt or MAPK Pathways

This study examined whether Kangen-karyu and its crude drug, Salviae Miltiorrhizae Radix, have a reno-protective effect on the age-related oxidative stress and inflammatory response through the phosphoinositide 3-kinase (PI3K)/Akt or mitogen-activated protein kinase (MAPK) pathways in aged rats. Kangen-karyu or Salviae Miltiorrhizae Radix (20 mg/kg body weight/day) was administered orally to old groups of rats for 16 days, and their effects were compared with the vehicle-treated old and young rats. The administration of Kangen-karyu caused a slight decrease in the serum glucose level and a significant decrease in the serum insulin level in the old rats. The increased levels of serum renal functional parameter (urea-nitrogen) and oxidative parameter were significantly reduced by both Kangen-karyu and Salviae Miltiorrhizae Radix. The old rats exhibited a dysregulation of the protein expression related to insulin resistance, oxidative stress, and inflammation in the kidneys, but Kangen-karyu administration significantly reduced the expression of the inflammatory proteins through the PI3K/Akt pathway. On the other hand, the Salviae Miltiorrhizae Radix-treated old rats showed a decrease in the inflammatory cytokines through the MAPK pathway. These results provide important evidence that Kangen-karyu and Salviae Miltiorrhizae Radix have a pleiotropic effect on the PI3K/Akt and MAPK pathways, showing renoprotective effects against the development of inflammation in old rats. This study provides scientific evidence that Kangen-karyu and Salviae Miltiorrhizae Radix improve the inflammatory responses via the PI3K/Akt or MAPK pathways in the kidney of old rats.

Neuromodulatory effects of hesperidin in mitigating oxidative stress in streptozotocin induced diabetes

Oxidative stress has been implicated in pathogenesis of streptozotocin- (STZ-) induced diabetes mellitus and its complication in central nervous system (CNS). Recent studies have provided insights on antioxidants and their emergence as potential therapeutic and nutraceutical. The present study examined the hypothesis that hesperidin (HP) ameliorates oxidative stress and may be a limiting factor in the extent of CNS complication following diabetes. To test this hypothesis rats were divided into four groups: control, diabetic, diabetic-HP treated, and vehicle for HP treatment group. Diabetes mellitus was induced by a single injection of STZ (65 mg/kg body weight). Three days after STZ injection, HP was given (50 mg/kg b.wt. orally) once daily for four weeks. The results of the present investigation suggest that the significant elevated levels of oxidative stress markers were observed in STZ-treated animals, whereas significant depletion in the activity of nonenzymatic antioxidants and enzymatic antioxidants was witnessed in diabetic rat brain. Neurotoxicity biomarker activity was also altered significantly. HP treatment significantly attenuated the altered levels of oxidative stress and neurotoxicity biomarkers. Our results demonstrate that HP exhibits potent antioxidant and neuroprotective effects on the brain tissue against the diabetic oxidative damage in STZ-induced rodent model.

Oxidative damage and autophagy in the human trabecular meshwork as related with ageing

Autophagy is an intracellular lysosomal degradation process induced under stress conditions. Autophagy also plays a major role in ocular patho-physiology. Molecular aging does occur in the trabecular meshwork, the main regulator of aqueous humor outflow, and trabecular meshwork senescence is accompanied by increased oxidative stress. However, the role of autophagy in trabecular meshwork patho-physiology has not yet been examined in vivo in human ocular tissues. The purpose of the herein presented study is to evaluate autophagy occurrence in ex-vivo collected human trabecular meshwork specimens and to evaluate the relationship between autophagy, oxidative stress, and aging in this tissue. Fresh trabecular meshwork specimens were collected from 28 healthy corneal donors devoid of ocular pathologies and oxidative DNA damage, and LC3 and p62 protein expression analyzed. In a subset of 10 subjects, further to trabecular meshwork proteins, the amounts of cathepesin L and ubiquitin was analyzed by antibody microarray in aqueous humor. Obtained results demonstrate that autophagy activation, measured by LC3II/I ratio, is related with. oxidative damage occurrence during aging in human trabecular meshwork. The expression of autophagy marker p62 was lower in subjects older than 60 years as compared to younger subjects. These findings reflect the occurrence of an agedependent increase in the autophagy as occurring in the trabecular meshwork. Furthermore, we showed that aging promotes trabecular-meshwork senescence due to increased oxidative stress paralleled by autophagy increase. Indeed, both oxidative DNA damage and autophagy were more abundant in subjects older than 60 years. These findings shed new light on the role of oxidative damage and autophagy during trabecular-meshwork aging.

The role of mitochondria in longevity and healthspan

The role of mitochondria in aging and disease remains contentious more than 40 years after the mitochondrial free radical theory of aging was first proposed. As part of a wider cross-journal series on contemporary mitochondrial biology, Longevity & Healthspan presents a thematic series of four reviews that discuss the evidence for and against the modern incarnations of the theory, and examine the relevance of mitochondrial membrane phospholipid unsaturation and the interactions of mitochondria with sex hormones.

Lactobacillus pentosus var. plantarum C29 ameliorates memory impairment and inflammaging in a D-galactose-induced accelerated aging mouse model

Aging is associated with Alzheimer's disease (AD), cardiovascular disease and cancer. Oxidative stress is considered as a major factor that accelerates the aging process. To understand the ability of lactic acid bacteria to ameliorate memory impairment caused by aging, we investigated the effect of Lactobacillus pentosus var. plantarum (C29), which is known to protect against scopolamine-induced memory impairment, on oxidative stress (D-galactose)-induced memory impairment in mice. D-Galactose was subcutaneously injected to 20-week old male C57BL/6J mice for 10 weeks, with oral administration of C29 for the final 5 weeks. Excessive intake of D-galactose not only impaired memory, which was indicated by passive avoidance, Y-maze, and Morris water-maze tasks, but also reduced the expression of brain-derived neurotrophic factor (BDNF) and hippocampal doublecortin (DCX) and the activation of cAMP response element-binding protein (CREB). C29 treatment ameliorated D-galactose-induced memory impairment and reversed the suppression of BDNF and DCX expression and CREB activation. Moreover, C29 decreased the expression of a senescence marker p16 and inflammation markers p-p65, p-FOXO3a, cyclooxygenase (COX)-2, and inducible NO synthase (iNOS). C29 treatment inhibited D-galactose-induced expression of M1 polarization markers tumor necrosis factor-α and arginase II, and attenuated the d-galactose-suppressed expression of M2 markers IL-10, arginase I and CD206. Taken together, these findings suggest that C29 may ameliorate memory impairment and M1 macrophage-polarized inflammation caused by aging.

Neuroprotective effect of ebselen against intracerebroventricular streptozotocin-induced neuronal apoptosis and oxidative stress in rats

The goal of this study was to examine the neuroprotective effect of ebselen against intracerebroventricular streptozotocin (ICV-STZ)-induced oxidative stress and neuronal apoptosis in rat brain. A total of 30 adult male Sprague-Dawley rats were randomly divided into 3 groups of 10 animals each: control, ICV-STZ, and ICV-STZ treated with ebselen. The ICV-STZ group rats were injected bilaterally with ICV-STZ (3 mg/kg) on days 1 and 3, and ebselen (10 mg/kg/day) was administered for 14 days starting from 1st day of ICV-STZ injection to day 14. Rats were killed at the end of the study and brain tissues were removed for biochemical and histopathological investigation. Our results demonstrated, for the first time, the neuroprotective effect of ebselen on Alzheimer's disease (AD) model in rats. Our present study, in ICV-STZ group, showed significant increase in tissue malondialdehyde levels and significant decrease in enzymatic antioxidants superoxide dismutase and glutathione peroxidase in the frontal cortex tissue. The histopathological studies in the brain of rats also supported that ebselen markedly reduced the ICV-STZ-induced histopathological changes and well preserved the normal histological architecture of the frontal cortex tissue. The number of apoptotic neurons was increased in frontal cortex tissue after ICV-STZ administration. Treatment of ebselen markedly reduced the number of degenerating apoptotic neurons. The study demonstrates the effectiveness of ebselen, as a powerful antioxidant, in preventing the oxidative damage and morphological changes caused by ICV-STZ in rats. Thus, ebselen may have a therapeutic value for the treatment of AD.

Oxidative stress in aging--matters of the heart and mind

Oxidative damage is considered to be the primary cause of several aging associated disease pathologies. Cumulative oxidative damage tends to be pervasive among cellular macromolecules, impacting proteins, lipids, RNA and DNA of cells. At a systemic level, events subsequent to oxidative damage induce an inflammatory response to sites of oxidative damage, often contributing to additional oxidative stress. At a cellular level, oxidative damage to mitochondria results in acidification of the cytoplasm and release of cytochrome c, causing apoptosis. This review summarizes findings in the literature on oxidative stress and consequent damage on cells and tissues of the cardiovascular system and the central nervous system, with a focus on aging-related diseases that have well-documented evidence of oxidative damage in initiation and/or progression of the disease. The current understanding of the cellular mechanisms with a focus on macromolecular damage, impacted cellular pathways and gross morphological changes associated with oxidative damage is also reviewed. Additionally, the impact of calorific restriction with its profound impact on cardiovascular and neuronal aging is addressed.

Naringenin ameliorates Alzheimer's disease (AD)-type neurodegeneration with cognitive impairment (AD-TNDCI) caused by the intracerebroventricular-streptozotocin in rat model

Oxidative stress is involved in Alzheimer's disease (AD)-type neurodegeneration with cognitive impairment (AD-TNDCI) as well as age related cognitive deficit. The present study was designed to investigate the pre-treatment effects of naringenin (NAR), a polyphenolic compound on cognitive dysfunction, oxidative stress in the hippocampus, and hippocampal neuron injury in a rat model of AD-TNDCI. The rats were pre-treated with NAR at a selective dose (50mg/kg, orally) for 2 weeks followed by intracerebroventricular-streptozotocin (ICV-STZ) (3mg/kg; 5μl per site) injection bilaterally. Behavioral alterations were monitored after 2 weeks from the lesion using passive avoidance test and Morris water maze paradigm. Three weeks after the lesion, the rats were sacrificed for measuring non-enzymatic [4-hydroxynonenal (4-HNE), malonaldehyde (MDA), thiobarbituric reactive substances (TBARS), hydrogen peroxide (H(2)O(2)), protein carbonyl (PC), reduced glutathione (GSH)] content and enzymatic [glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT) and Na(+)/K(+)-ATPase] activity in the hippocampus, and expression of choline acetyltransferase (ChAT) positive neuron, and histopathology of hippocampal neurons. The non-enzymatic level and enzymatic activity was significantly increased and decreased, respectively, with striking impairments in spatial learning and memory, loss of ChAT positive neuron and severe damage to hippocampal neurons in the rat induced by ICV-STZ. These abnormalities were significantly improved by NAR pre-treatment. The study suggests that NAR can protect against cognitive deficits, neuronal injury and oxidative stress induced by ICV-STZ, and may be used as a potential agent in treatment of neurodegenerative diseases such as AD-TNDCI.

Gpx4 ablation in adult mice results in a lethal phenotype accompanied by neuronal loss in brain

Glutathione peroxidase 4 (Gpx4) is an antioxidant defense enzyme important in reducing hydroperoxides in membrane lipids and lipoproteins. Gpx4 is essential for survival of embryos and neonatal mice; however, whether Gpx4 is required for adult animals remains unclear. In this study, we generated a floxed Gpx4 mouse (Gpx4(f/f)), in which exons 2-4 of Gpx4 gene are flanked by loxP sites. We then cross-bred the Gpx4(f/f) mice with a tamoxifen (tam)-inducible Cre transgenic mouse (R26CreER mice) to obtain mice in which the Gpx4 gene could be ablated by tam administration (Gpx4(f/f)/Cre mice). After treatment with tam, adult Gpx4(f/f)/Cre mice (6-9 months of age) showed a significant reduction of Gpx4 levels (a 75-85% decrease) in tissues such as brain, liver, lung, and kidney. Tam-treated Gpx4(f/f)/Cre mice lost body weight and died within 2 weeks, indicating that Gpx4 is essential for survival of adult animals. Tam-treated Gpx4(f/f)/Cre mice exhibited increased mitochondrial damage, as evidenced by the elevated 4-hydroxylnonenal (4-HNE) level, decreased activities of electron transport chain complexes I and IV, and reduced ATP production in liver. Tam treatment also significantly elevated apoptosis in Gpx4(f/f)/Cre mice. Moreover, tam-treated Gpx4(f/f)/Cre mice showed neuronal loss in the hippocampus region and had increased astrogliosis. These data indicate that Gpx4 is essential for mitochondria integrity and survival of neurons in adult animals.

Attenuation of age-related changes in FOXO3a activity and the PI3K/Akt pathway by short-term feeding of ferulate

Ferulate (4-hydroxy-3-methoxycinnamic acid) is a well-known phenolic compound that scavenges free radicals and exerts anti-inflammatory effects. Forkhead box O3a (FOXO3a), a transcription factor that plays important roles in aging processes, decreases with age and is negatively regulated through phosphorylation by phosphatidylinositol 3-kinase (PI3K)/Akt signaling. The present study investigated the efficacy of short-term ferulate feeding on age-related changes in PI3K/Akt/FOXO3a and upstream insulin signaling pathways in aged rats. In addition, changes in manganese superoxide dismutase (MnSOD) and catalase expression were examined because of their dependence on PI3K/Akt/FOXO3a activity. Short-term feeding experiments were done with a diet containing ferulate that was given to aged rats at doses of 3 or 6 mg kg(-1) day(-1) for 10 days. Results showed that FOXO3a activity was increased in the ferulate-fed old group compared with the control old group. Also, ferulate suppressed the PI3K/Akt signaling pathway that is responsible for FOXO3a inhibition in aged rats. Plasma insulin levels and the upstream insulin signaling pathway were also modulated by ferulate correspondingly with PI3K/Akt/FOXO3a activity. The age-related decrease in two major antioxidant enzymes, MnSOD and catalase, was blunted by ferulate, which was accompanied by FOXO3a transcriptional activity. The significance of the present study is the finding that short-term feeding of ferulate effectively modulates age-related renal FOXO3a, PI3K/Akt and insulin signaling pathways, and MnSOD and catalase expression, all of which may be beneficial for attenuating the aging process.

Silymarin protects neurons from oxidative stress associated damages in focal cerebral ischemia: a behavioral, biochemical and immunohistological study in Wistar rats

Cerebral stroke is the third largest cause of death and the severe leading cause of disability, thus have astronomical financial and social burden worldwide. Accumulated evidence suggests that ROS can be scavenged through utilizing natural antioxidant compounds present in foods and medicinal plants. In this study, we examined whether silymarin, an antioxidant, present in the milk of thistle can prevent or slowdown neuronal injury in focal cerebral ischemia. Male Wistar rats were pre-treated with silymarin (200mg/kg body weight, dissolved in 0.3 % sodium carboxymethyl cellulose, once orally) for 15 days. On day 16, they underwent a transient 2h suture-occlusion of the middle cerebral artery followed by 22 h of reperfusion. Rats were tested for neurobehavioral activity after 22 h reperfusion. Silymarin was found to be successful in upregulating the antioxidant status and lowering the apoptotic responses, and functional recovery returned close to the baseline. This study revealed that silymarin, a naturally occurring flavone from the milk thistle (Silybum marianum), may be helpful in slowing down the progression of neurodegeneration in focal cerebral ischemia. These results suggest that the neuroprotective potential of silymarin is mediated through its anti-oxidative and anti-apoptotic properties.

Modulation of the apoptotic pathway in skeletal muscle models: the role of growth hormone

Despite numerous studies on the role of growth hormone (GH), its function in skeletal muscle apoptosis secondary to various stimuli is poorly understood. In this study, we used rodent muscle cell lines to analyse cell growth and survival as well as the morphological and molecular markers of cell death in C2C12 and L6C5 myoblasts. These cells were treated either in the presence or absence of GH under serum starvation conditions or in the pro-apoptotic concentrations of hydrogen peroxide (H2O2). Although the cells were responsive to the presence of GH, we did not observe GH modulation of cell growth and survival. The presence of GH did not affect the cell death programme or the expression of apoptotic markers in basal conditions or under oxidative stress. In conclusion, this study indicated that GH "by itself" is not effective in modulating the intracellular pathways leading to cell survival or cell death induced by apoptotic stimuli.

Free radical scavenging and antiacetylcholinesterase activities of Origanum majorana L. essential oil

In the present study, Origanum majorana L. essential oil (EO) was analyzed by gas chromatography-mass spectrometry (GC-MS) and evaluated for free radical scavenging and anticholinesterase activities. GC-MS analysis revealed the presence of 4-terpineol (29.97%), γ-terpinene (15.40%), trans-sabinene hydrate (10.93), α-terpinene (6.86%), 3-cycolohexene-1-1 methanal,a,a4-trimethyl-,(S)-(CAS) (6.54%), and sabinene (3.91%) as main constituents. Origanum majorana L. EO exhibited concentration-dependent inhibitory effects on 2,2'-diphenylpicrylhydrazyl (DPPH(•)), hydroxyl radical, hydrogen peroxide, reducing power, and lipid peroxidation with IC(50) values of 58.67, 67.11, 91.25, 78.67, and 68.75 µg/mL, respectively; while the IC(50) values for the standard trolox were noted to be 23.95, 44.97, 51.30, 42.22, and 52.72 µg/mL, respectively. Interestingly, cholinesterase inhibitory activity was also found with IC(50) values of 36.40 µg/mL. We can conclude that the marjoram EO has a significant potential to be used as a natural antioxidant and anti-AChE.

Long-term treatment with a "Yang-invigorating" Chinese herbal formula, Wu-Zi-Yan-Zong-Wan, reduces mortality and liver oxidative damage in chronic alcohol-intoxicated rats

Long-term alcohol consumption has been reported to increase oxidative stress in multiple organs and accelerate the aging process. A previous study in our laboratory has shown that Wu-Zi-Yan-Zong-Wan (WZ), a "Yang-invigorating" Chinese herbal formula, protected against ethanol-induced toxicity in HepG2 cells transfected to express human CYP2E1, presumably by enhancing mitochondrial antioxidant status and functional ability. The present study aims to investigate whether WZ extract treatment can afford protection against chronic ethanol-induced oxidative stress (a major risk factor of aging) and mortality in rats. The effect of the extract (1.8 g, 4.5 g, and 9 g raw materials/kg per day) on chronic ethanol hepatotoxicity was investigated in rats receiving steady intragastric infusion of ethanol-containing liquid diet. The results showed that long-term (42 days) herbal co-treatment protected against chronic ethanol-induced mortality and hepatotoxicity and in rats, as evidenced by decreased plasma transaminases activities. The extract also suppressed the pathological development of fatty liver, as assessed by histopathological examination and the ratio of liver weight to body weight. The hepatoprotection afforded by the extract was associated with decreases in the extents of reactive oxygen species production, lipid peroxidation, and oxidative modification of proteins, as well as the reversal of altered mitochondrial reduced glutathione level. The results suggest that the suppressive effect of WZ on chronic ethanol-induced oxidative stress and mortality may be attributed to the antioxidant action, particularly in mitochondria.

Age-related protective effect of deprenyl on changes in the levels of diagnostic marker enzymes and antioxidant defense enzymes activities in cerebellar tissue in Wistar rats

Antioxidants are free radical scavengers and protect living organisms against oxidative damage to tissues. Experimental evidence implicates oxygen-derived free radicals as important causative agents of aging and the present study was designed to evaluate the age-related effects of deprenyl on the antioxidant defense in the cerebellum of male Wistar rats. Experimental rats of three age groups (6, 12, and 18 months old) were administered with liquid deprenyl (2 mg/kg body weight/day for a period of 15 days i.p) and levels of diagnostic marker enzymes (alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and creatine phosphokinase) in plasma, lipid peroxides, reduced glutathione and activities of glutathione-dependent antioxidant enzymes (glutathione peroxidase and glutathione-S-transferase) and antiperoxidative enzymes (catalase and superoxide dismutase) in the cerebellar tissue were determined. Intraperitonial administration of deprenyl (2 mg/kg body weight/day for a period of 15 days) significantly (p < 0.05) attenuated the age-related alterations noted in the levels of diagnostic marker enzymes plasma of experimental animals. Deprenyl also exerted an antioxidant effect against aging process by hindering lipid peroxidation to an extent. Moderate rise in the levels of reduced glutathione and activities of glutathione-dependent antioxidant enzymes and antiperoxidative enzymes was also observed. The results of the present investigation indicated that the protective potential of deprenyl was probably due to the increase of the activity of the free radical scavenging enzymes or to a counteraction of free radicals by its antioxidant nature or to a strengthening of neuronal membrane by its membrane-stabilizing action. Histopathological observations also confirmed the protective effect of deprenyl against the age-related aberrations in rat cerebellum. These data on the effect of deprenyl on parameters of normal aging provides new additional information concerning the anti-aging potential of deprenyl.