Protective effects of resveratrol on hydrogen peroxide-induced apoptosis in rat pheochromocytoma (PC12) cells

Oxidative stress has been considered as a major cause of cellular injuries in a variety of clinical abnormalities. One of the plausible ways to prevent the reactive oxygen species (ROS)-mediated cellular injury is dietary or pharmaceutical augmentation of endogenous antioxidant defense capacity. Resveratrol (3,5,4'-trihydroxy-trans-stilbene), one of the major antioxidative constituents found in the skin of grapes, has been considered to be responsible in part for the protective effects of red wine consumption against coronary heart disease ('French Pardox'). In this study, we have investigated the effects of resveratrol on hydrogen peroxide-induced oxidative stress and apoptotic death in cultured rat pheochromocytoma (PC12) cells. PC12 cells treated with hydrogen peroxide underwent apoptotic death as determined by characteristic morphological features, internucleosomal DNA fragmentation and positive in situ end-labeling by terminal transferase (TUNEL staining). Resveratrol pretreatment attenuated hydrogen peroxide-induced cytotoxicity, DNA fragmentation, and intracellular accumulation of ROS. Hydrogen peroxide transiently induced activation of NF-kappaB in PC12 cells, which was mitigated by resveratrol pretreatment. These results suggest that resveratrol has the potential to prevent oxidative stress-induced cell death.     

Effect of resveratrol on high glucose-induced stress in human leukemia K562 cells

Hyperglycemia, a symptom of diabetes mellitus, induces hyperosmotic responses, including apoptosis, in vascular endothelial cells and leukocytes. Hyperosmotic shock elicits a stress response in mammalian cells, often leading to apoptotic cell death. In a previous report, we showed that hyperosmotic shock induced apoptosis in various mammalian cells. Importantly, apoptotic biochemical changes (i.e., caspase-3 activation and DNA fragmentation) were blocked by antioxidant pretreatment during hyperosmotic shock-induced cell death. In the present study, we report that resveratrol, a phytoalexin present in grapes with known antioxidant and anti-inflammatory properties, attenuates high glucose-induced apoptotic changes, including c-Jun N-terminal kinase (JNK) activation and caspase-3 activation in human leukemia K562 cells. Experiments with the cell permeable dye, 2',7'-dichlorofluorescein diacetate (DCF-DA), an indicator of reactive oxygen species (ROS) generation, revealed that high glucose treatment directly increased intracellular oxidative stress, which was attenuated by resveratrol. In addition, high glucose-treated K562 cells displayed a lower degree of attachment to collagen, the major component of vessel wall subendothelium. In contrast, cells pretreated with resveratrol followed by high glucose exhibited higher affinity for collagen. The results of this report collectively imply the involvement of oxidative stress in high glucose-induced apoptosis and alterations in attachment ability. Moreover, resveratrol blocks these events by virtue of its antioxidant property.     

Vitamin E prevents cell death induced by mild oxidative stress in chicken skeletal muscle cells

Apoptosis and necrosis are two forms of cell death that can occur in response to various agents and oxidative damage. In addition to necrosis, apoptosis contributes to muscle fiber loss in various muscular dystrophies as well participates in the exudative diathesis in chicken, pathology caused by dietary deficiency of vitamin E and selenium, which affects muscle tissue. We have used chicken skeletal muscle cells and bovine fibroblasts to study molecular events involved in the cell death induced by oxidative stress and apoptotic agents. The effect of vitamin E on cell death induced by oxidants was also investigated. Treatment of cells with anti-Fas antibody (50 to 400 ng/mL), staurosporine (0.1 to 100 microM) and TNF-alpha (10 and 50 ng/mL) resulted in a little loss of Trypan blue exclusion ability. Those stimuli conducted cells to apoptosis detected by an enhancement in caspase activity upon fluorogenic substrates but this activity was not fully blocked by the caspase inhibitor Z-VAD-fmk. Oxidative stress induced by menadione (10, 100 and 250 muM) promoted a significant reduction in cell viability (10%, 20% and 35% for fibroblasts; 20%, 30% and 75% for muscle cells, respectively) and caused an increase in caspase activity and DNA fragmentation. H2O2 also promoted apoptosis verified by caspase activation and DNA fragmentation, but in higher doses induced necrosis. Vitamin E protected cells from death induced by low doses of oxidants. Although it was ineffective in reducing caspase activity in fibroblasts, this vitamin diminished the enzyme activity in muscle cells. These data suggested that oxidative stress could activate apoptotic mechanisms; however the mode of cell death will depend on the intensity and duration of the stimulus, and on the antioxidant status of the cells.     

Resveratrol increases vascular oxidative stress resistance

Epidemiological studies suggest that Mediterranean diets rich in resveratrol are associated with reduced risk of coronary artery disease. However, the mechanisms by which resveratrol exerts its vasculoprotective effects are not completely understood. Because oxidative stress and endothelial cell injury play a critical role in vascular aging and atherogenesis, we evaluated whether resveratrol inhibits oxidative stress-induced endothelial apoptosis. We found that oxidized LDL and TNF-alpha elicited significant increases in caspase-3/7 activity in endothelial cells and cultured rat aortas, which were prevented by resveratrol pretreatment (10(-6)-10(-4) mol/l). The protective effect of resveratrol was attenuated by inhibition of glutathione peroxidase and heme oxygenase-1, suggesting a role for antioxidant systems in the antiapoptotic action of resveratrol. Indeed, resveratrol treatment protected cultured aortic segments and/or endothelial cells against increases in intracellular H(2)O(2) levels and H(2)O(2)-mediated apoptotic cell death induced by oxidative stressors (exogenous H(2)O(2), paraquat, and UV light). Resveratrol treatment also attenuated UV-induced DNA damage (comet assay). Resveratrol treatment upregulated the expression of glutathione peroxidase, catalase, and heme oxygenase-1 in cultured arteries, whereas it had no significant effect on the expression of SOD isoforms. Resveratrol also effectively scavenged H(2)O(2) in vitro. Thus resveratrol seems to increase vascular oxidative stress resistance by scavenging H(2)O(2) and preventing oxidative stress-induced endothelial cell death. We propose that the antioxidant and antiapoptotic effects of resveratrol, together with its previously described anti-inflammatory actions, are responsible, at least in part, for its cardioprotective effects.     

Protective Effects of Resveratrol and Quercetin Against MPP<Superscript>+</Superscript> -Induced Oxidative Stress Act by Modulating Markers of Apoptotic Death in Dopaminergic Neurons

Reactive oxygen species produced by oxidative stress may participate in the apoptotic death of dopamine neurons distinctive of Parkinson’s disease. Resveratrol, a red wine extract, and quercetin, found mainly in green tea, are two natural polyphenols, presenting antioxidant properties in a variety of cellular paradigms. The aim of this study was to evaluate the effect of resveratrol and quercetin on the apoptotic cascade induced by the administration of 1-methyl-4-phenylpyridinium ion (MPP⁺), a Parkinsonian toxin, provoking the selective degeneration of dopaminergic neurons. Our results show that a pre-treatment for 3 h with resveratrol or quercetin before MPP⁺ administration could greatly reduce apoptotic neuronal PC12 death induced by MPP⁺. We also demonstrated that resveratrol or quercetin modulates mRNA levels and protein expression of Bax, a pro-apoptotic gene, and Bcl-2, an anti-apoptotic gene. We then evaluated the release of cytochrome c and the nuclear translocation of the apoptosis-inducing factor (AIF). Altogether, our results indicate that resveratrol and quercetin diminish apoptotic neuronal cell death by acting on the expression of pro- and anti-apoptotic genes. These findings support the role of these natural polyphenols in preventive and/or complementary therapies for several human neurodegenerative diseases caused by oxidative stress and apoptosis.     

Insulin neuroprotection against oxidative stress in cortical neurons--involvement of uric acid and glutathione antioxidant defenses

In this study we investigated the effect of insulin on neuronal viability and antioxidant defense mechanisms upon ascorbate/Fe2+-induced oxidative stress, using cultured cortical neurons. Insulin (0.1 and 10 microM) prevented the decrease in neuronal viability mediated by oxidative stress, decreasing both necrotic and apoptotic cell death. Moreover, insulin inhibited ascorbate/Fe2+-mediated lipid and protein oxidation, thus decreasing neuronal oxidative stress. Increased 4-hydroxynonenal (4-HNE) adducts on GLUT3 glucose transporters upon exposure to ascorbate/Fe2+ were also prevented by insulin, suggesting that this peptide can interfere with glucose metabolism. We further analyzed the influence of insulin on antioxidant defense mechanisms in the cortical neurons. Oxidative stress-induced decreases in intracellular uric acid and GSH/GSSG levels were largely prevented upon treatment with insulin. Inhibition of phosphatidylinositol-3-kinase (PI-3K) or mitogen-induced extracellular kinase (MEK) reversed the effect of insulin on uric acid and GSH/GSSG, suggesting the activation of insulin-mediated signaling pathways. Moreover, insulin stimulated glutathione reductase (GRed) and inhibited glutathione peroxidase (GPx) activities under oxidative stress conditions, further supporting that insulin neuroprotection was related to the modulation of the glutathione redox cycle. Thus, insulin may be useful in preventing oxidative stress-mediated injury that occurs in several neurodegenerative disorders.     

Glutathione depletion-induced chromosomal DNA fragmentation associated with apoptosis and necrosis

Chromosomal DNA and mitochondrial dysfunctions play a role on mammalian cell death induced by oxidative stress. The major biochemical dysfunction of chromosome is the presence of an ordered cleavage of the DNA backborn, which is separated and visualized as an electrophoretic pattern of fragments. Oxidative stress provides chromatin dysfunction such as single strand and double strand DNA fragmentation leading to cell death. More than 1 Mb of giant DNA, 200-800 kb or 50-300 kb high molecular weight (HMW) DNA and internucleosomal DNA fragments are produced during apoptosis or necrosis induced by oxidative stress such as glutathione (GSH) depletion in several types of mammalian cells. Reactive oxygen species (ROS)-mediated DNA fragmentation is enhanced by polyunsaturated fatty acids including arachidonic acid or their hydroperoxides, leading to necrosis. Mitochondrial dysfunction on decrease of trans membrane potential, accumulation of ROS, membrane permeability transition and release of apoptotic factors during apoptosis or necrosis has been implicated. This review refers to the correlation of chromosomal DNA fragmentation and apoptosis or necrosis induced by GSH depletion, and the possible mechanisms of oxidative stress-induced cell death.     

The lipid peroxidation end-product 4-HNE induces COX-2 expression through p38MAPK activation in 3T3-L1 adipose cell

Oxidative stress and low grade chronic inflammation are increased in accumulating fat. Our objective was to test whether 4-hydroxynonenal (4-HNE), an end-product of lipid peroxidation, affects cyclooxygenases in 3T3-L1 adipose cells. 4-HNE increased COX-2 mRNA and protein expression and p38MAP-kinase phosphorylation in a dose-dependent manner. Pretreatment of 3T3-L1 cells by a selective inhibitor of p38MAPK (PD 169316) abolished 4-HNE and glucose oxidase induced COX-2 expression. Our results show that oxidative stress induces COX-2 expression through the production of 4-HNE which activates p38MAPKinase, suggesting that 4-HNE links oxidative stress and chronic inflammation through the activation of cyclooxygenase.     

Diclofenac induced in vivo nephrotoxicity may involve oxidative stress-mediated massive genomic DNA fragmentation and apoptotic cell death.

Diclofenac (DCLF) is a nonsteroidal anti-inflammatory drug that is widely used for the treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and acute muscle pain conditions. Toxic doses of DCLF can cause nephrotoxicity in humans and experimental animals. However, whether this DCLF-induced nephrotoxicity involves apoptotic cell death in addition to necrosis is unknown. The goals of this investigation were to determine whether DCLF-induced nephrotoxicity involves oxidative stress and apoptotic type genomic DNA fragmentation, and if so, whether DCLF-induced oxidative stress and DNA fragmentation cause apoptotic cell death in mouse kidneys. Male ICR mice (CD-1; 25-45 g), fed ad libitum, were administered nephrotoxic doses of DCLF (100, 200, 300 mg/Kg, po) and sacrificed 24 h later. Blood was collected to evaluate renal injury (BUN), lipid peroxidation (MDA: malondialdehyde levels), and superoxide dismutase (SOD) activity (a marker of oxidative stress). Kidney tissues were analyzed both quantitatively and qualitatively to determine the degree and type of DNA damage, and evaluated histopathologically for the presence of apoptotic characteristics in the nucleus of diverse types of kidney cells. Results show that diclofenac is a powerful nephrotoxicant (at 100, 200, and 300 mg/kg: 4.7-, 4.9-, and 5.0-fold increases in BUN compared to the control, respectively) and a strong inducer of oxidative stress (significant increase in MDA levels). Oxidative stress induced by DCLF was also coupled with massive kidney DNA fragmentation (100, 200, and 300 mg/kg: 3-, 8-, and 10-fold increases compared to control, respectively). A dose-dependent increase in MDA levels and SOD activity was also observed, which indicated a link between oxidative stress and nephrotoxicity. Qualitative analysis of DNA fragmentation by gel electrophoresis showed a DNA ladder indicative of Ca2+-Mg2+-endonuclease activation. Histopathological examination of kidney sections revealed numerous apoptotic nuclei across proximal and distal tubular cell linings. Collectively, these data for the first time suggest that DCLF-induced nephrotoxicity may involve production of reactive oxygen species leading to oxidative stress and massive genomic DNA fragmentation, and these two free radical mediated events may ultimately translate into apoptotic cell death of kidney cells in vivo, and reveal a DNA-active role for DCLF.     

Induction of necrotic cell death by oxidative stress in retinal pigment epithelial cells

Age-related macular degeneration (AMD) is a degenerative disease of the retina and the leading cause of blindness in the elderly. Retinal pigment epithelial (RPE) cell death and the resultant photoreceptor apoptosis are characteristic of late-stage dry AMD, especially geographic atrophy (GA). Although oxidative stress and inflammation have been associated with GA, the nature and underlying mechanism for RPE cell death remains controversial, which hinders the development of targeted therapy for dry AMD. The purpose of this study is to systematically dissect the mechanism of RPE cell death induced by oxidative stress. Our results show that characteristic features of apoptosis, including DNA fragmentation, caspase 3 activation, chromatin condensation and apoptotic body formation, were not observed during RPE cell death induced by either hydrogen peroxide or tert-Butyl hydroperoxide. Instead, this kind of cell death can be prevented by RIP kinase inhibitors necrostatins but not caspase inhibitor z-VAD, suggesting necrotic feature of RPE cell death. Moreover, ATP depletion, receptor interacting protein kinase 3 (RIPK3) aggregation, nuclear and plasma membrane leakage and breakdown, which are the cardinal features of necrosis, were observed in RPE cells upon oxidative stress. Silencing of RIPK3, a key protein in necrosis, largely prevented oxidative stress-induced RPE death. The necrotic nature of RPE death is consistent with the release of nuclear protein high mobility group protein B1 into the cytoplasm and cell medium, which induces the expression of inflammatory gene TNFα in healthy RPE and THP-1 cells. Interestingly, features of pyroptosis or autophagy were not observed in oxidative stress-treated RPE cells. Our results unequivocally show that necrosis, but not apoptosis, is a major type of cell death in RPE cells in response to oxidative stress. This suggests that preventing oxidative stress-induced necrotic RPE death may be a viable approach for late-stage dry AMD.     

Bcl-2 protects against hyperoxia-induced apoptosis through inhibition of the mitochondria-dependent pathway

Bcl-2 is an antiapoptotic molecule that prevents oxidative stress damage and cell death. We investigated the possible protective mechanisms mediated by Bcl-2 during hyperoxia-induced cell death in L929 cells. In these cells, hyperoxia promoted apoptosis without DNA fragmentation. Overexpression of Bcl-2 significantly protected cells from oxygen-induced apoptosis, as shown by measurement of lactate dehydrogenase release, quantification of apoptotic nuclei, and detection of Annexin-V-positive cells. Bcl-2 partially prevented mitochondrial damage and interfered with the mitochondrial proapoptotic signaling pathway: it reduced Bax translocation to mitochondria, decreased the release of cytochrome c, and inhibited caspase 3 activation. However, treatment with the caspase inhibitor Z-VAD.fmk failed to rescue the cells from death, indicating that protection provided by Bcl-2 was due not only to caspase inhibition. Bcl-2 also prevented the release of mitochondrial apoptotic inducing factor, a mediator of caspase-independent apoptosis, correlating with the absence of oligonucleosomal DNA fragmentation. In addition, Bcl-2-overexpressing cells showed significantly higher intracellular amounts of glutathione after 72 h of oxygen exposure. In conclusion, our results demonstrate that the overexpression of Bcl-2 is able to prevent hyperoxia-induced cell death, by affecting mitochondria-dependent apoptotic pathways and increasing intracellular antioxidant compounds.     

Aldh3a1 protects human corneal epithelial cells from ultraviolet- and 4-hydroxy-2-nonenal-induced oxidative damage

Aldehyde dehydrogenase 3A1 (ALDH3A1) is one of the most abundant proteins found in corneal epithelial cells of mammalian species, with several postulated protective roles that include detoxification of peroxidic aldehydes, scavenging of free radicals, and direct absorption of ultraviolet (UV) radiation. In the present study, the protective role of ALDH3A1 against UV- and 4-hydroxy-2-nonenal- (4-HNE-) induced oxidative damage was studied. For this purpose, human ALDH3A1 was stably transfected in a human corneal epithelial cell line (HCE) lacking endogenous enzyme. Cells transfected with ALDH3A1 were more resistant to UV- and 4-HNE-induced cytotoxicity than mock-transfected cells. DNA fragmentation assays revealed that both treatments induced apoptosis in mock-transfected cells, but not in ALDH3A1-expressing cells. Apoptosis appeared to occur via caspase-3 activation and subsequent PARP cleavage. The Michaelis-Menten constant (K(m)) for 4-HNE was 54 microM in ALDH3A1-transfected cells; the addition of 100 microM 4-HNE increased NAD(P)H levels by 50% above that in mock-transfected cells. We also found that ALDH3A1 expression prevented 4-HNE-induced protein adduct formation. Taken together, these data suggest that ALDH3A1 is a regulatory element of the cellular defense system that protects corneal epithelium against UV- and 4-HNE-induced oxidative damage.     

Intracellular methylglyoxal induces oxidative damage to pancreatic beta cell line INS-1 cell through Ire1α-JNK and mitochondrial apoptotic pathway

An increased intracellular methylglyoxal (MGO) under hyperglycemia led to pancreatic beta cell death. However, its mechanism in which way with MGO induced beta cell death remains unknown. We investigated both high glucose and MGO treatment significantly inclined intracellular MGO concentration and inhibited cell viability in vitro. MGO treatment also triggered intracellular advanced glycation end products (AGEs) formation, declined mitochondrial membrane potential (MMP), increased oxidative stress and the expression of ER stress mediators Grp78/Bip and p-PERK; activated mitochondrial apoptotic pathway, which could mimic by Glo1 knockdown. Aminoguanidine (AG), a MGO scavenger, however, prevented AGEs formation and MGO-induced cell death by inhibiting oxidative stress and ER stress. Furthermore, both antioxidant N-acetylcysteine (NAC) and ER stress inhibitor 4-phenylbutyrate (4-PBA) could attenuate MGO-induced cell death through ameliorating ER stress. MGO treatment down-regulated Ire1α, a key ER stress mediator, increased JNK phosphorylation and activated mitochondrial apoptosis; down-regulated Bcl-2 expression which could be attenuated by the JNK inhibitor SP600125 and further inhibited cytochrome c leakage from mitochondria and blocked the conversion of pro caspase 3 into cleaved caspase 3, all these might contribute to the inhibition of INS-1 cell apoptosis. Ire1α down-regulation by Ire1α siRNAs mimicked MGO-induced cytotoxicity by activating the JNK phosphorylation and mitochondrial apoptotic pathway. In summary, we demonstrated that increased intracellular MGO induced cytotoxicity in INS-1 cells primarily by activating oxidative stress and further triggering mitochondrial apoptotic pathway, and ER stress-mediated Ire1α-JNK pathway. These findings may have implication on new mechanism of glucotoxicity-mediated pancreatic beta-cell dysfunction.     

Adaptive responses to the stress induced by hyperthermia or hydrogen peroxide in human fibroblasts

Perturbation of oxidant/antioxidant cellular balance, induced by cellular metabolism and by exogenous sources, causes deleterious effects to proteins, lipids, and nucleic acids, leading to a condition named "oxidative stress" that is involved in several diseases, such as cancer, ischemia-reperfusion injury, and neurodegenerative disorders. Among the exogenous agents, both H(2)O(2) and hyperthermia have been implicated in oxidative stress promotion linked with the activation of apoptotic or necrotic mechanisms of cell death. The goal of this work was to better understand the involvement of some stress-related proteins in adaptive responses mounted by human fibroblasts versus the oxidative stress differently induced by 42 degrees C hyperthermia or H(2)O(2.) The research was developed, switching off inducible nitric oxide synthase (iNOS) expression through antisense oligonucleotide transfection by studying the possible coregulation in the expression of HSP32 (also named HO-1), HSP70, and iNOS and their involvement in the induction of DNA damage. Several biochemical parameters, such as cell viability (MTT assay), cell membrane integrity (lactate dehydrogenase release), reactive oxygen species formation, glutathione levels, immunocytochemistry analysis of iNOS, HSP70, and HO-1 levels, genomic DNA fragmentation (HALO/COMET assay), and transmembrane mitochondrial potential (deltaPsi) were examined. Cells were collected immediately at the end of the stress-inducing treatment. The results, confirming the pleiotropic function of i-NOS, indicate that: (i). HO-1/HSP32, HSP70, and iNOS are finely tuned in their expression to contribute all together, in human fibroblasts, in ameliorating the resistance to oxidative stress damage; (ii). ROS exposure, at least in hyperthermia, in human fibroblasts contributes to growth arrest more than to apoptosis activation; and (iii). mitochondrial dysfunction, in presence of iNOS inhibition seems to be clearly involved in apoptotic cell death of human fibroblasts after H(2)O(2) treatment, but not after hyperthermia.     

Apoptosis induced by selenium in human glioma cell lines

Several studies have shown that selenium can inhibit tumorigenesis in tissues. However, little is known about the mechanism and the effect of selenium on DNA, especially in brain tumor cells. In this study we examined the biological effect of selenium on human glioma cell lines (A172 and T98G). Selenium exhibited an antiproliferative effect on these cell lines (and induced the typical ladder pattern of DNA fragmentation commonly found in apoptosis), which were prevented by catalase. Few effects of selenium on NTI4 fibroblasts were found. These findings demonstrate that selenium may induce, by apoptosis, cell death of human glioma cell lines, which are resulting from free radical oxygen forming.     

Lipopolysaccharide prevents apoptosis induced by brefeldin A, an endoplasmic reticulum stress agent, in RAW 264.7 cells

The effect of lipopolysaccharide (LPS) on the cell death induced by endoplasmic reticulum (ER) stress agents in RAW 264.7 cells was studied. LPS prevented the cell death by brefeldin A, but not thapsigargin and tunicamycin. CpG DNA as well as LPS prevented brefeldin A-induced cell death whereas tumor necrosis factor-alpha or interferon-gamma did not. Brefeldin A-induced cell death was mediated with apoptotic cell death and it was significantly inhibited by LPS. LPS abolished the activation of ER stress-related caspases, such as caspases 1, 3, and 4. LPS prevented brefeldin A-induced morphological changes in RAW 264.7 cells. Further, LPS prevented brefeldin A-induced Golgi dispersion. Therefore, LPS was suggested to diminish the stress of ER/Golgi complexes induced by brefeldin A and inhibit apoptosis. The preventive action of LPS on brefeldin A-induced apoptosis is discussed.     

Protective role of a coumarin-derived schiff base scaffold against tertiary butyl hydroperoxide (TBHP)-induced oxidative impairment and cell death via MAPKs, NF-κB and mitochondria-dependent pathways

The present study investigated the antioxidant signalling mechanism of a coumarin-derived schiff base (CSB) scaffold against tert-butylhydroperoxide (TBHP) induced oxidative insult in murine hepatocytes. CSB possesses DPPH and other free radical scavenging activities. TBHP reduced cell viability and intracellular antioxidant status accompanied by an increase in intracellular ROS production in hepatocytes. TBHP also activated phospho-ERK1/2, phospho-p38 and NF-κB, altered the Bcl-2/Bad ratio, reduced mitochondrial membrane potential, released cytochrome C and activated caspase 3, suggesting that TBHP induced oxidative stress responsive cell death via apoptotic pathway. FACS analysis and DNA fragmentation studies also confirmed the apoptotic cell death in TBHP exposed hepatocytes. Treatment with CSB effectively reduced these adverse effects by preventing the oxidative insult, alteration in the redox-sensitive signalling cascades and mitochondrial events. Combining, results suggest that antioxidant property of CSB make the molecule to be a potential protective measure against oxidative insult, cytotoxicity and cell death.