3-Bromopyruvate elevates ROS and induces hormesis to exert a caloric restriction mimetic effect in young and old rats.

CONTEXT: 3-Bromopyruvate (3-BP) is a glycolytic inhibitor and a putative caloric restriction mimetic. OBJECTIVE: We have examined the effect of low-dose administration of 3-BP to rats and assess the CRM effect by measuring an array of biomarkers of oxidative stress. MATERIALS AND METHODS: Male Wistar young and old rats were administered with a low-dose 3-BP for four weeks. RESULTS: A significant increase in ROS was observed in 3-BP-treated rats (both young and old), an increase in erythrocyte PMRS (plasma membrane redox system), FRAP (Ferric reducing ability of plasma), catalase and superoxide dismutase activities were also observed. Treatment with 3-BP also reduced protein carbonyl, advanced oxidation protein products, plasma sialic acid, and advanced glycation end products. CONCLUSION: Short-term 3-BP treatment can provide protection against oxidant stress. We suggest that 3-BP triggers a hormetic response subsequent to an increase in ROS leading to the induction of a protective defense mechanism.

3-Bromopyruvate, a caloric restriction mimetic, exerts a mitohormetic effect to provide neuroprotection through activation of autophagy in rats during aging.

In the present study, attempts have been made to evaluate the potential role of 3 Bromopyruvate (3-BP) a glycolytic inhibitor and a caloric restriction mimetic (CRM), to exert neuroprotection in rats during aging through modulation of autophagy. Young male rats (4 months), and naturally aged (22 months) male rats were supplemented with 3-BP (30 mg/kg b.w., orally) for 28 days. Our results demonstrate a significant increase in the antioxidant biomarkers (ferric reducing antioxidant potential level, total thiol, superoxide dismutase, and catalase activities) and a decrease in the level of pro-oxidant biomarkers such as protein carbonyl after 3-BP supplementation in brain tissues. A significant increase in reactive oxygen species (ROS) was observed due to the mitohormetic effect of 3-BP supplementation in the treated rats. Furthermore, the 3-BP treatment also enhanced the activities of electron transport chain complexes I and IV in aged brain mitochondria thus proving its antioxidant potential at the level of mitochondria. Gene expression analysis with reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to assess the expression of autophagy, neuroprotective and aging marker genes. RT-PCR data revealed that 3-BP up-regulated the expression of autophagy markers genes (Beclin-1 and LC3 ß), sirtuin-1, and neuronal marker gene (NSE), respectively in the aging brain. The results suggest that 3-BP induces a mitohormetic effect through the elevation of ROS which reinforces defensive mechanism(s) targeted at regulating autophagy. These findings suggest that consistently low-dose 3-BP may be beneficial for neuroprotection during aging and age-related disorders.

Hormetic Effect of 3-Bromopyruvate on Age-Induced Alterations in Erythrocyte Membrane Transporters and Oxidative Biomarkers in Rats.

3-Bromopyruvate (3-BP) is a glycolytic inhibitor and a potential calorie restriction mimic that shows a variety of beneficial effects in several aging model systems. A chronic low dose of 3-BP was given to male Wistar rats for 4 weeks. The effect of 3-BP on age-dependent alteration on the activities of various transporters/exchangers and redox biomarkers (protein carbonyl [PC], sialic acid [SA], sulfhydryl group [-SH], intracellular calcium ion [Ca2+]i, and osmotic fragility) was studied. In aged rats, 3-BP treatment increases the membrane-bound activities of Na+/K+-ATPase (NKA) and Ca2+-ATPase (PMCA), along with levels of -SH and SA. It also exerts a concomitant decrease in Na+/H+ exchanger (NHE) activity and the levels of [Ca2+]i, PC, and osmotic fragility in aged groups. 3-BP can be considered as a potential antiaging agent that induces a hormetic effect leading to amelioration of age-dependent impairment of membrane-bound ATPases and alterations in the redox biomarker level.

Baicalein May Act as a Caloric Restriction Mimetic Candidate to Improve the Antioxidant Profile in a Natural Rodent Model of Aging.

Caloric restriction (CR) is the most effective intervention for extending the life span of vertebrate and invertebrate aging models. Calorie restriction mimetics (CRMs), which are synthetic or natural chemicals that mimic the biochemical, hormonal, and physiological consequences of calorie restriction, are being researched for antiaging benefits. Baicalein is a plant-derived polyphenol that has the potential of antioxidant, anti-inflammatory, and autophagy inducer. The objective of this study is to evaluate the antiaging, anti-inflammatory, and antioxidant role of Baicalein in erythrocyte membrane and plasma, and evaluate the efficacy of Baicalein to act as a CRM candidate. This study evaluates the effect of Baicalein on aging biomarkers in normal and aged rats. We study various pro- and antioxidant markers, erythrocyte membrane transporters, and eryptosis. Baicalein supplementation in male Wistar rats significantly alleviated pro-oxidant markers and improved antioxidant profile. Improvement was also observed in age-induced alterations in membrane transporters, and eryptosis. Based on the aforementioned observations we conclude that Baicalein has the potential to maintain extracellular reactive oxygen species levels and redox homeostasis during the aging process, an effect that is similar to CR. Thus, Baicalein may be a potent CRM candidate for antiaging interventions.

Metformin ameliorates acetaminophen-induced sub-acute toxicity via antioxidant property.

Acetaminophen or N-acetyl-p-amino-phenol (APAP) is a drug which is available over-the-counter for fever and pain. Its overdosing causes oxidative stress and subsequent acute liver damage. In the present study, we scrutinized the protective effect of metformin co-treatment in APAP induced blood and liver sub-acute toxicity. This is a pre-clinical study in which male Wistar Rats (BW: 300 ± 20 g) were orally co-treated with APAP (1 g/kg/day) and metformin (300 mg/kg/day) for 28-days. Pro- and anti-oxidant markers viz reactive oxygen species, protein carbonyl, malondialdehyde (MDA), the ferric reducing ability of plasma (FRAP), plasma membrane redox system(PMRS) and reduced glutathione (GSH) were evaluated in blood. Additionally, in liver tissue, catalase (CAT), superoxide dismutase (SOD), MDA and GST level were also evaluated. Histological study and estimation of alanine aminotransferase (ALT), and aspartate aminotransferase (AST) level in serum were performed. APAP induces pro-oxidant markers as well as reduces anti-oxidant markers in blood and liver. Hepatic tissues degeneration and vacuolization of hepatocytes were evident after APAP treatment. Metformin treatment reduces pro-oxidant markers as well as increases anti-oxidant markers in both tissues. It also improves liver tissue architecture after treatment. The outcome of this study suggests that metformin has protective capability against APAP-induced blood and liver toxicity. Thus, metformin co-treatment with APAP attenuates oxidative stress and its consequences.

Fisetin, a potential caloric restriction mimetic, modulates ionic homeostasis in senescence induced and naturally aged rats.

CONTEXT: Fisetin as a caloric restriction mimetic (CRM) exerts numerous beneficial effects on different aging model systems. The effect of fisetin on erythrocyte membrane functions against induced aging is not very clear. OBJECTIVES: The potential role of fisetin in the modulation of erythrocytes membrane-bound transporters during natural and induced aging in rats was assessed. MATERIALS AND METHODS: Male Wistar rats were used for natural and D-galactose (D-gal) induced aging model. After supplementation with fisetin, the activities of different membrane transporters and biomarkers of oxidative stress were evaluated. RESULTS: Fisetin modulated membrane transporters such as calcium-ATPase, sodium potassium-ATPase and sodium hydrogen exchanger during senescence-induced as well as in natural aging. Fisetin also protected oxidative modifications in rat aging. DISCUSSION AND CONCLUSION: Fisetin supplementation improves the ionic homeostasis, a factor that is involved in the aetiology of several age-associated diseases, in naturally old as well as D-gal induced aged rats.

Baicalein maintains redox balance in experimental hyperlipidemic rats.

Context: An altered lipid profile may lead to the development of CVD.Objective: We evaluated the protective role of baicalein (BAC) against lipidemic and oxidative stress in hyperlipidemic challenged Wistar rats.Materials and methods: Male Wistar rats were given a high-fat diet (HFD) (suspension (w/v) of 0.5% cholesterol, 3% coconut oil and 0.25% cholic acid for 30 days) to create a hyperlipidemic model. BAC was supplemented to experimental rats (80 mg/kg body weight). Biomarkers of oxidative stress including ROS, FRAP, GSH, PMRS, AGE, MDA, PCO, AOPP, and other parameters (Paraoxonase-1, SGOT, SGPT) including TNF-α and IL-6, were estimated in blood.Results: Oxidative stress and inflammatory markers were significantly increased in the HFD treated group. BAC treatment protected rats from HFD mediated alterations.Discussion & conclusion: Our results indicate that baicalein provides protection against hyperlipidemic stress and redox imbalance induced by HFD in rats.

Plasma from Young Rats Injected into Old Rats Induce Antiaging Effects.

An experimental novel antiaging intervention strategy is based on the concept of parabiosis, which involves long-term treatment with factors derived from young blood facilitating rejuvenation of old individuals. In this study, we employed blood plasma from young rats as an intervention strategy to evaluate whether this could impact aging biomarkers in aged rats. The biomarkers studied include: reactive oxygen species, the ferric reducing ability of plasma, plasma membrane redox system, reduced glutathione, malondialdehyde, protein carbonyl, and advanced oxidation protein products in blood. Additionally, the level of tumor necrosis factor-α and interleukin-6 were also estimated in blood. We found that old rats injected with plasma from young rats were protected from oxidative stress. Thus, this study provides some evidence of the rejuvenating effects of young plasma. We hypothesize that young plasma may contain certain "factors," which may be responsible for the observed effects. The mechanism of action is not clearly understood and is open to further studies.

Metformin protects red blood cells against rotenone induced oxidative stress and cytotoxicity.

CONTEXT: The anti-diabetic medicine metformin has been reported as an anti-ageing drug candidate as it mimics the benefits of caloric restriction and reduces ageing-related oxidative stress in various experimental organisms. OBJECTIVE: We investigated the possible anti-oxidative role of metformin against rotenone-induced oxidative stress and cytotoxicity in erythrocytes of Wistar rats. Rotenone is a well-known inducer of oxidative stress which leads to a cellular redox imbalance. MATERIALS AND METHODS: We have co-exposed the experimental rats with rotenone (2.5 mg/kg, i.p.) and metformin (300 mg/kg, orally) for 30 days to investigate the protective effects of metformin on various rotenone-induced impaired oxidative stress biomarkers in rat erythrocytes. RESULTS: We found that a significant alleviation in the levels of rotenone-induced pro-oxidant and anti-oxidant markers following exposure of metformin. DISCUSSION AND CONCLUSIONS: Our findings suggest that metformin supplementation shows a protective role in against rotenone-induced redox imbalance and cytotoxicity in rat erythrocytes.

Mitochondrial VDAC1-based peptides: Attacking oncogenic properties in glioblastoma.

Glioblastoma multiforme (GBM), a primary brain malignancy characterized by high morbidity, invasiveness, proliferation, relapse and mortality, is resistant to chemo- and radiotherapies and lacks effective treatment. GBM tumors undergo metabolic reprograming and develop anti-apoptotic defenses. We targeted GBM with a peptide derived from the mitochondrial protein voltage-dependent anion channel 1 (VDAC1), a key component of cell energy, metabolism and apoptosis regulation. VDAC1-based cell-penetrating peptides perturbed cell energy and metabolic homeostasis and induced apoptosis in several GBM and GBM-derived stem cell lines. We found that the peptides simultaneously attacked several oncogenic properties of human U-87MG cells introduced into sub-cutaneous xenograft mouse model, inhibiting tumor growth, invasion, and cellular metabolism, stemness and inducing apoptosis. Peptide-treated tumors showed decreased expression of all tested metabolism-related enzymes and transporters, and elevated levels of apoptotic proteins, such as p53, cytochrome c and caspases. Retro-Tf-D-LP4, containing the human transferrin receptor (TfR)-recognition sequence, crossed the blood-brain barrier (BBB) via the TfR that is highly expressed in the BBB to strongly inhibit tumor growth in an intracranial xenograft mouse model. In summary, the VDAC1-based peptides tested here offer a potentially affordable and innovative new conceptual therapeutic paradigm that might overcome GBM stemness and invasiveness and reduce relapse rates.

The mitochondrial voltage-dependent anion channel 1 in tumor cells.

VDAC1 is found at the crossroads of metabolic and survival pathways. VDAC1 controls metabolic cross-talk between mitochondria and the rest of the cell by allowing the influx and efflux of metabolites, ions, nucleotides, Ca2+ and more. The location of VDAC1 at the outer mitochondrial membrane also enables its interaction with proteins that mediate and regulate the integration of mitochondrial functions with cellular activities. As a transporter of metabolites, VDAC1 contributes to the metabolic phenotype of cancer cells. Indeed, this protein is over-expressed in many cancer types, and silencing of VDAC1 expression induces an inhibition of tumor development. At the same time, along with regulating cellular energy production and metabolism, VDAC1 is involved in the process of mitochondria-mediated apoptosis by mediating the release of apoptotic proteins and interacting with anti-apoptotic proteins. The engagement of VDAC1 in the release of apoptotic proteins located in the inter-membranal space involves VDAC1 oligomerization that mediates the release of cytochrome c and AIF to the cytosol, subsequently leading to apoptotic cell death. Apoptosis can also be regulated by VDAC1, serving as an anchor point for mitochondria-interacting proteins, such as hexokinase (HK), Bcl2 and Bcl-xL, some of which are also highly expressed in many cancers. By binding to VDAC1, HK provides both a metabolic benefit and apoptosis-suppressive capacity that offer the cell a proliferative advantage and increase its resistance to chemotherapy. Thus, these and other functions point to VDAC1 as an excellent target for impairing the re-programed metabolism of cancer cells and their ability to evade apoptosis. Here, we review current evidence pointing to the function of VDAC1 in cell life and death, and highlight these functions in relation to both cancer development and therapy. In addressing the recently solved 3D structures of VDAC1, this review will point to structure-function relationships of VDAC as critical for deciphering how this channel can perform such a variety of roles, all of which are important for cell life and death. Finally, this review will also provide insight into VDAC function in Ca2+ homeostasis, protection against oxidative stress, regulation of apoptosis and involvement in several diseases, as well as its role in the action of different drugs. We will discuss the use of VDAC1-based strategies to attack the altered metabolism and apoptosis of cancer cells. These strategies include specific siRNA able to impair energy and metabolic homeostasis, leading to arrested cancer cell growth and tumor development, as well VDAC1-based peptides that interact with anti-apoptotic proteins to induce apoptosis, thereby overcoming the resistance of cancer cell to chemotherapy. Finally, small molecules targeting VDAC1 can induce apoptosis. VDAC1 can thus be considered as standing at the crossroads between mitochondrial metabolite transport and apoptosis and hence represents an emerging cancer drug target. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.

Carryover of cigarette smoke effects on hematopoietic cytokines to F1 mouse litters.

Neutrophils have been implicated in the pathogenesis of COPD, being recruited into the lung in response to cigarette smoke (CS) inhalation and responsible for the release of proteases and oxidant-producing enzymes, resulting in bronchitis and emphysema. Several hematopoietic cytokines are involved in neutrophil growth and recruitment; however, little is known about the effects of CS on hematopoietic cytokines are transmitted between generations. In the present investigation we evaluate the expression of hematopoietic and proinflammatory cytokines in different organs of female F(0) mice subjected to sub-chronic CS exposure, and in F(1) litters. Virgin female Balb/c mice inhaled either air or air containing CS for 90 days. The specific resistance of the airways (sRaw) was evaluated and, thereafter, the mice were mated with unexposed adult males. The levels of granulocyte-macrophage colony stimulating factor (GM-CSF), granulocyte-colony stimulating factor (G-CSF), interleukin-6 (IL-6), IL-1ß and TNF-α mRNA and protein were evaluated in the bone marrow, amniotic fluid and bronchoalveolar lavage fluid (BALF) of F(0) dams at gestation day(14) (gd(14)) and the bone marrow, BALF and lungs of F(0) dams and F(1) littermates at post natal day(21) (pnd(21)). At gd(14), overexpression of GM-CSF, G-CSF and IL-6 mRNA and protein was observed in the bone marrow, amniotic fluid and BALF of F(0) dams. These hematopoietic cytokines were also overexpressed in the lungs of F(1) littermates compared with the control F(1) litters at pnd(21). Lineage-specific hematopoietic growth factors may play an important role in the transmission of neutrophil-associated disease susceptibility across generations.

IL-6 receptor-mediated lung Th2 cytokine networking in silica-induced pulmonary fibrosis.

Pulmonary silicosis is a deadly disease which kills thousands of people every year worldwide. The disease initially develops as an inflammatory response with recruitment of inflammatory cells into the lung controlled by multiple cytokines. The question whether these cytokines exert biological functions through signal transducing pathway remains unanswered along with the potential role of interleukin-6 receptor α (IL-6Rα) in regulating inflammatory cytokines. We aimed to assess the status of signal transducers and activator of transcription (Stat3), suppressor of cytokine signalling 3(Socs3) and inflammatory cytokines in airways of silica-exposed mice, and their relationship with IL-6Rα. Silica-exposed and silica-exposed IL-6Rα gene knockdown Balb/c mice were used in the study. Lung function was measured by plethysmography, mRNA expression of cytokines and signal molecules by qRT(2)-PCR and lung architecture by histopathology; T helper cell-type 2 (Th2) cytokines in broncho-alveolar lavage fluids were evaluated by ELISA and hydroxyproline in lung by colorimetry. Elevated levels of collagen deposition, signs of lung fibrosis, infiltration of inflammatory cells and presence of exfoliated mucosa in the lung of silica-exposed mice with concurrent increase in methacholine-induced specific resistance of airways were observed on day 60 post-exposure. In parallel, heightened expression of Th2 cytokines (IL-4, IL-5, IL-6) and signal molecules (Stat3 and Socs3) were observed in the airways of silica-exposed mice. Th1 (IL-1ß and TNF-α) cytokines are underexpressed in majority of the airways tissues of silica-exposed mice. Silencing IL-6Rα in lung of silica-exposed mice down regulated the hypermorphic mRNA pool of potential Th2 cytokines and signal molecules. Hypermorphic expression of Th2 cytokines and signal molecules in airways of silica-exposed mice are mediated through IL-6Rα.