scholarly journals Ethyl acetate extract of germinated brown rice attenuates hydrogen peroxide-induced oxidative stress in human SH-SY5Y neuroblastoma cells: role of anti-apoptotic, pro-survival and antioxidant genes

Author(s):  
Nur Hanisah Azmi ◽  
Norsharina Ismail ◽  
Mustapha Umar Imam ◽  
Maznah Ismail
Pharmacologia ◽  
2011 ◽  
Vol 2 (12) ◽  
pp. 355-361
Author(s):  
Ngueguim Tsofack Florence ◽  
Tabi Nkoulou Thierry ◽  
Dzeufiet Djomeni Paul Desir ◽  
Tsala David Emeryb ◽  
Dongmo Alain Blaise ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Nur Diyana Md Zamri ◽  
Mustapha Umar Imam ◽  
Siti Aisyah Abd Ghafar ◽  
Maznah Ismail

The antioxidant properties of germinated brown rice (GBR) are likely mediated by multiple bioactives. To test this hypothesis, HepG2 cells pretreated with GBR extracts, rich in acylated steryl glycoside (ASG), gamma amino butyric acid GABA), phenolics or oryzanol, were incubated with hydrogen peroxide (H2O2) and their hydroxyl radical (OH•) scavenging capacities and thiobarbituric acid-reactive substances (TBARS) generation were evaluated. Results showed that GBR-extracts increased OH•scavenging activities in both cell-free medium and posttreatment culture media, suggesting that the extracts were both direct- and indirect-acting against OH•. The levels of TBARS in the culture medium after treatment were also reduced by all the extracts. In addition, H2O2produced transcriptional changes in p53, JNK, p38 MAPK, AKT, BAX, and CDK4 that were inclined towards apoptosis, while GBR-extracts showed some transcriptional changes (upregulation of BAX and p53) that suggested an inclination for apoptosis although other changes (upregulation of antioxidant genes, AKT, JNK, and p38 MAPK) suggested that GBR-extracts favored survival of the HepG2 cells. Our findings show that GBR bioactive-rich extracts reduce oxidative stress through improvement in antioxidant capacity, partly mediated through transcriptional regulation of antioxidant and prosurvival genes.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 940
Author(s):  
Muganti Rajah Kumar ◽  
Swee Keong Yeap ◽  
Han Chung Lee ◽  
Nurul Elyani Mohamad ◽  
Muhammad Nazirul Mubin Aziz ◽  
...  

Kefir, a fermented probiotic drink was tested for its potential anti-oxidative, anti-apoptotic, and neuroprotective effects to attenuate cellular oxidative stress on human SH-SY5Y neuroblastoma cells. Here, the antioxidant potentials of the six different kefir water samples were analysed by total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH) assays, whereas the anti-apoptotic activity on hydrogen peroxide (H2O2) induced SH-SY5Y cells was examined using MTT, AO/PI double staining, and PI/Annexin V-FITC assays. The surface and internal morphological features of SH-SY5Y cells were studied using scanning and transmission electron microscopy. The results indicate that Kefir B showed the higher TPC (1.96 ± 0.54 µg GAE/µL), TFC (1.09 ± 0.02 µg CAT eq/µL), FRAP (19.68 ± 0.11 mM FRAP eq/50 µL), and DPPH (0.45 ± 0.06 mg/mL) activities compared to the other kefir samples. The MTT and PI/Annexin V-FITC assays showed that Kefir B pre-treatment at 10 mg/mL for 48 h resulted in greater cytoprotection (97.04%), and a significantly lower percentage of necrotic cells (7.79%), respectively. The Kefir B pre-treatment also resulted in greater protection to cytoplasmic and cytoskeleton inclusion, along with the conservation of the surface morphological features and the overall integrity of SH-SY5Y cells. Our findings indicate that the anti-oxidative, anti-apoptosis, and neuroprotective effects of kefir were mediated via the upregulation of SOD and catalase, as well as the modulation of apoptotic genes (Tp73, Bax, and Bcl-2).


2022 ◽  
Author(s):  
Zhao Huang ◽  
Li Zhou ◽  
Jiufei Duan ◽  
Siyuan Qin ◽  
Yu Wang ◽  
...  

Abstract Loss of E-cadherin (ECAD), often caused by epigenetic inactivation, is closely associated with tumor metastasis. However, how ECAD is regulated in response to oxidative stress during tumorigenesis is largely unknown. Here we identify RNF25 as a new E3 ligase of ECAD, whose activation by oxidative stress leads to ECAD protein degradation in hepatocellular carcinoma (HCC). Loss of ECAD activates YAP, which in turn promotes the transcription of RNF25, thus forming a positive feedback loop to sustain the ECAD downregulation. YAP activation mitigates oxidative stress in detached HCC cells by upregulating antioxidant genes, protecting detached HCC cells from ferroptosis, resulting in anoikis resistance. Mechanistically, we found that protein kinase A (PKA) senses oxidative stress by redox modification in its β catalytic subunit (PRKACB) at Cys200 and Cys344, which increases its kinase activity towards RNF25 phosphorylation at Ser450, facilitating RNF25-mediated degradation of ECAD. Moreover, RNF25 expression is associated with HCC metastasis and depletion of RNF25 is sufficient to diminish HCC invasion and metastasis in vitro and in vivo. Together, these results identify a dual role of RNF25 as a critical regulator of ECAD protein turnover, promoting both anoikis resistance and metastasis, and PKA is a necessary redox sensor to enable this process. Our study provides mechanistic insight into how tumor cells sense oxidative stress signals to spread while escaping cell death.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ana Díaz ◽  
Raúl López-Grueso ◽  
Juan Gambini ◽  
Daniel Monleón ◽  
Cristina Mas-Bargues ◽  
...  

Females live longer than males, and the estrogens are one of the reasons for this difference. We reported some years ago that estrogens are able to protect rats against oxidative stress, by inducing antioxidant genes. Type 2 diabetes is an age-associated disease in which oxidative stress is involved, and moreover, some studies show that the prevalence is higher in men than in women, and therefore there are sex-associated differences. Thus, the aim of this study was to evaluate the role of estrogens in protecting against oxidative stress in type 2 diabetic males and females. For this purpose, we used Goto-Kakizaki rats, which develop type 2 diabetes with age. We found that female diabetic rats showed lower glycaemia levels with age than did diabetic males and that estrogens enhanced insulin sensitivity in diabetic females. Moreover, glucose uptake, measured by positron emission tomography, was higher in the female brain, cerebellum, and heart than in those from male diabetic rats. There were also sex-associated differences in the plasma metabolic profile as determined by metabolomics. The metabolic profile was similar between estrogen-replaced and control diabetic rats and different from ovariectomized diabetic rats. Oxidative stress is involved in these differences. We showed that hepatic mitochondria from females produced less hydrogen peroxide levels and exhibited lower xanthine oxidase activity. We also found that hepatic mitochondrial glutathione oxidation and lipid oxidation levels were lower in diabetic females when compared with diabetic males. Ovariectomy induced oxidative stress, and estrogen replacement therapy prevented it. These findings provide evidence for estrogen beneficial effects in type 2 diabetes and should be considered when prescribing estrogen replacement therapy to menopausal women.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Chitra Basu ◽  
Runa Sur

Hydrogen peroxide (H2O2) mediated oxidative stress leading to hepatocyte apoptosis plays a pivotal role in the pathophysiology of several chronic liver diseases. This study demonstrates that S-allyl cysteine (SAC) renders cytoprotective effects on H2O2 induced oxidative damage and apoptosis in HepG2 cells. Cell viability assay showed that SAC protected HepG2 cells from H2O2 induced cytotoxicity. Further, SAC treatment dose dependently inhibited H2O2 induced apoptosis via decreasing the Bax/Bcl-2 ratio, restoring mitochondrial membrane potential (∆Ψm), inhibiting mitochondrial cytochrome c release, and inhibiting proteolytic cleavage of caspase-3. SAC protected cells from H2O2 induced oxidative damage by inhibiting reactive oxygen species accumulation and lipid peroxidation. The mechanism underlying the antiapoptotic and antioxidative role of SAC is the induction of the heme oxygenase-1 (HO-1) gene in an NF-E2-related factor-2 (Nrf-2) and Akt dependent manner. Specifically SAC was found to induce the phosphorylation of Akt and enhance the nuclear localization of Nrf-2 in cells. Our results were further confirmed by specific HO-1 gene knockdown studies which clearly demonstrated that HO-1 induction indeed played a key role in SAC mediated inhibition of apoptosis and ROS production in HepG2 cells, thus suggesting a hepatoprotective role of SAC in combating oxidative stress mediated liver diseases.


2018 ◽  
Vol 374 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Fazal Ur Rehman Bhatti ◽  
Song Ja Kim ◽  
Ae-Kyung Yi ◽  
Karen A. Hasty ◽  
Hongsik Cho

2010 ◽  
Vol 6 ◽  
pp. e32-e32
Author(s):  
Lin Zheng ◽  
Nodi Dehvari ◽  
Eirikur Benedikz ◽  
Richard Cowburn ◽  
Alexei Terman ◽  
...  

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2737-2737
Author(s):  
Richard A. Wells ◽  
Chunhong Gu ◽  
Joelle dela Paz

Abstract Abstract 2737 Poster Board II-713 Background Although patients with acute myelogenous leukaemia (AML) typically respond well to initial therapy, with over 75% of patients achieving complete remission, in the great majority the disease ultimately relapses. This is thought to be due to the inherent resistance of leukaemia stem cells to the effects of chemotherapy. While some mechanisms of chemoresistance, e.g. TP53 mutation and upregulation of P-glycoprotein expression, have been well characterized, this phenomenon remains incompletely understood and is a significant barrier to improving patient outcomes. Methods and results The thiazolidindione drug troglitazone (TG) induces apoptosis in AML cells via generation of intracellular reactive oxygen species (ROS), but the degree of sensitivity to TG is highly heterogeneous among AML cell lines. We studied expression of the transcription factor ARNT (aryl hydrocarbon nuclear translocator) in TG-sensitive and TG-resistant AML cell lines following TG treatment. In HL-60 cells, which are highly sensitive to induction of apoptosis by TG, ARNT mRNA levels remained constant following TG treatment and ARNT protein levels markedly decreased, while in U937 cells, which are TG resistant, ARNT mRNA levels increased and ARNT protein levels remained constant. We then tested the effect of exogenous expression of ARNT on the sensitivity of HL-60 cells to TG-induced apoptosis. HL-60 cells transduced with a retrovirus expressing ARNT became TG-resistant. Exogenous expression of ARNT also conferred resistance to induction of apoptosis by hydrogen peroxide, daunorubicin and etoposide. The cellular response to oxidative stress is governed by intracellular signaling pathways and through a transcriptional response through which expression of antioxidant genes is coordinated. HL-60 cells expressing ARNT had striking constitutive activation of AKT signaling, and treatment of these cells with a specific inhibitor of AKT signaling reversed their resistance to TG-induced apoptosis. The activation of AKT signaling by ARNT appears to be mediated by downregulation of expression of PP2A and alpha4, two key negative regulators of AKT phosphorylation. In addition, ARNT-transduced HL-60 cells showed increased expression of Nrf2, a key transcriptional regulator of the antioxidant response, and its target genes SOD2 and CAT. Conclusions The response to oxidative stress is heterogeneous in AML cells lines, and varies with expression of ARNT. ARNT activates expression of Nrf2, which stimulates expression of antioxidant genes resulting in an augmented adaptive response to ROS. Unexpectedly, ARNT also activates AKT signaling by repressing expression of the regulatory phosphatases PP2A and alpha4. These activities of ARNT result in increased resistance to the induction of apoptosis by TG, hydrogen peroxide, and chemotherapy. ARNT may play an important role in chemoresistance in and may be useful as a predictive or prognostic biomarker. Disclosures: No relevant conflicts of interest to declare.


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