The role of oxidative stress in the toxicity of pyridoxal isonicotinoyl hydrazone (PIH) analogues

2002 ◽  
Vol 30 (4) ◽  
pp. 755-758 ◽  
Author(s):  
J. L. Buss ◽  
J. Neuzil ◽  
P. Ponka

Pyridoxal isonicotinoyl hydrazone (PIH) analogues are effective iron chelators in vivo and in vitro, and may be of value for the treatment of secondary iron overload. The sensitivity of Jurkat cells to Fe-chelator complexes was enhanced several-fold by the depletion of the antioxidant glutathione, indicating the role of oxidative stress in their toxicity. K562 cells loaded with eicosapentaenoic acid, a fatty acid particularly susceptible to oxidation, were also more sensitive to the toxic effects of the Fe complexes, and toxicity was proportional to lipid peroxidation. Thus Fechelator complexes cause oxidative stress, which may be a major component of their toxicity. As was the case for their Fe complexes, the toxicity of PIH analogues was enhanced by glutathione depletion of Jurkat cells and eicosapentaenoic acidloading of K562 cells. Thus the toxicity of the chelators themselves is also enhanced by compromised cellular redox status. In addition, the toxicity of the chelators was diminished by culturing Jurkat cells under hypoxic conditions, which may limit the production of the reactive oxygen species that initiate oxidative stress. A significant part of the toxicity of the chelators may be due to intracellular formation of Fe-chelator complexes, which oxidatively destroy the cell.

2021 ◽  
Vol 22 (11) ◽  
pp. 5705
Author(s):  
Karolina Szewczyk-Golec ◽  
Marta Pawłowska ◽  
Roland Wesołowski ◽  
Marcin Wróblewski ◽  
Celestyna Mila-Kierzenkowska

Toxoplasma gondii is an apicomplexan parasite causing toxoplasmosis, a common disease, which is most typically asymptomatic. However, toxoplasmosis can be severe and even fatal in immunocompromised patients and fetuses. Available treatment options are limited, so there is a strong impetus to develop novel therapeutics. This review focuses on the role of oxidative stress in the pathophysiology and treatment of T. gondii infection. Chemical compounds that modify redox status can reduce the parasite viability and thus be potential anti-Toxoplasma drugs. On the other hand, oxidative stress caused by the activation of the inflammatory response may have some deleterious consequences in host cells. In this respect, the potential use of natural antioxidants is worth considering, including melatonin and some vitamins, as possible novel anti-Toxoplasma therapeutics. Results of in vitro and animal studies are promising. However, supplementation with some antioxidants was found to promote the increase in parasitemia, and the disease was then characterized by a milder course. Undoubtedly, research in this area may have a significant impact on the future prospects of toxoplasmosis therapy.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fangfang Tao ◽  
Yanrong Zhang ◽  
Zhiqian Zhang

Mitochondria are highly dynamic double-membrane organelles which play a well-recognized role in ATP production, calcium homeostasis, oxidation-reduction (redox) status, apoptotic cell death, and inflammation. Dysfunction of mitochondria has long been observed in a number of human diseases, including cancer. Targeting mitochondria metabolism in tumors as a cancer therapeutic strategy has attracted much attention for researchers in recent years due to the essential role of mitochondria in cancer cell growth, apoptosis, and progression. On the other hand, a series of studies have indicated that traditional medicinal herbs, including traditional Chinese medicines (TCM), exert their potential anticancer effects as an effective adjunct treatment for alleviating the systemic side effects of conventional cancer therapies, for reducing the risk of recurrence and cancer mortality and for improving the quality of patients’ life. An amazing feature of these structurally diverse bioactive components is that majority of them target mitochondria to provoke cancer cell-specific death program. The aim of this review is to summarize the in vitro and in vivo studies about the role of these herbs, especially their bioactive compounds in the modulation of the disturbed mitochondrial function for cancer therapy.


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. 1-11 ◽  
Author(s):  
Jing-Shang Wang ◽  
Ye Huang ◽  
Shuping Zhang ◽  
Hui-Jun Yin ◽  
Lei Zhang ◽  
...  

Hyperglycemia fluctuation is associated with diabetes mellitus (DM) complications when compared to persistent hyperglycemia. Previous studies have shown that paeoniflorin (PF), through its antiapoptosis, anti-inflammation, and antithrombotic properties, effectively protects against cardiovascular and cerebrovascular disease. However, the mechanism underlying the protection from PF against vascular injuries induced by hyperglycemia fluctuations remains poorly understood. Herein, we investigated the potential protective role of PF on human umbilical vein endothelial cells (HUVECs) subjected to intermittent glucose levels in vitro and in DM rats with fluctuating hyperglycemia in vivo. A remarkable increased apoptosis associated with elevated inflammation, increased oxidative stress, and high protein level of PKCβ1 was induced in HUVECs by intermittently changing glucose for 8 days, and PF recovered those detrimental changes. LY333531, a potent PKCβ1 inhibitor, and metformin manifested similar effects. Additionally, in DM rats with fluctuating hyperglycemia, PF protected against vascular damage as what has been observed in vitro. Taken together, PF attenuates the vascular injury induced by fluctuant hyperglycemia through oxidative stress inhibition, inflammatory reaction reduction, and PKCβ1 protein level repression, suggesting its perspective clinical usage.


2010 ◽  
Vol 23 (7) ◽  
pp. 962-976 ◽  
Author(s):  
Stephanie A. Gardiner ◽  
Jayanand Boddu ◽  
Franz Berthiller ◽  
Christian Hametner ◽  
Robert M. Stupar ◽  
...  

Trichothecenes are a major group of toxins produced by phytopathogenic fungi, including Fusarium graminearum. Trichothecenes inhibit protein synthesis in eukaryotic cells and are toxicologically relevant mycotoxins for humans and animals. Because they promote plant disease, the role of host responses to trichothecene accumulation is considered to be an important aspect of plant defense and resistance to fungal infection. Our overall objective was to examine the barley response to application of the type B trichothecene deoxynivalenol (DON). We found that DON is diluted by movement from the application site to acropetal and basipetal florets. A susceptible barley genotype converted DON to DON-3-O-glucoside, indicating that UDP-glucosyltransferases capable of detoxifying DON must exist in barley. RNA profiling of DON-treated barley spikes revealed strong upregulation of gene transcripts encoding ABC transporters, UDP-glucosyltransferases, cytochrome P450s, and glutathione-S-transferases. We noted that transcripts encoding cysteine synthases were dramatically induced by DON, and that toxin-sensitive yeast on glutathione- or cysteine-supplemented media or carrying a gene that encodes a cysteine biosynthetic enzyme exhibit DON resistance, suggesting that preventing glutathione depletion by increasing cysteine supply could play a role in ameliorating the impact of DON. Evidence for nonenzymatic formation of DON-glutathione adducts in vitro was found using both liquid chromatography–mass spectrometry and nuclear magnetic resonance analysis, indicating that the formation of DON-glutathione conjugates in vivo may reduce the impact of trichothecenes. Our results indicate that barley exhibits multiple defense mechanisms against trichothecenes.


2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Iwona Zwolak

Vanadium (V) in its inorganic forms is a toxic metal and a potent environmental and occupational pollutant and has been reported to induce toxic effects in animals and people. In vivo and in vitro data show that high levels of reactive oxygen species are often implicated in vanadium deleterious effects. Since many dietary (exogenous) antioxidants are known to upregulate the intrinsic antioxidant system and ameliorate oxidative stress-related disorders, this review evaluates their effectiveness in the treatment of vanadium-induced toxicity. Collected data, mostly from animal studies, suggest that dietary antioxidants including ascorbic acid, vitamin E, polyphenols, phytosterols, and extracts from medicinal plants can bring a beneficial effect in vanadium toxicity. These findings show potential preventive effects of dietary antioxidants on vanadium-induced oxidative stress, DNA damage, neurotoxicity, testicular toxicity, and kidney damage. The relevant mechanistic insights of these events are discussed. In summary, the results of studies on the role of dietary antioxidants in vanadium toxicology appear encouraging enough to merit further investigations.


Reproduction ◽  
2013 ◽  
Vol 146 (6) ◽  
pp. R217-R227 ◽  
Author(s):  
Tessa Lord ◽  
R John Aitken

With extended periods of time following ovulation, the metaphase II stage oocyte experiences deterioration in quality referred to as post-ovulatory oocyte ageing. Post-ovulatory ageing occurs both in vivo and in vitro and has been associated with reduced fertilization rates, poor embryo quality, post-implantation errors and abnormalities in the offspring. Although the physiological consequences of post-ovulatory oocyte ageing have largely been established, the molecular mechanisms controlling this process are not well defined. This review analyses the relationships between biochemical changes exhibited by the ageing oocyte and the symptoms associated with the ageing phenotype. We also discuss molecular events that are potentially involved in orchestrating post-ovulatory ageing with a particular focus on the role of oxidative stress. We propose that oxidative stress may act as the initiator for a cascade of events that create the aged oocyte phenotype. Specifically, oxidative stress has the capacity to cause a decline in levels of critical cell cycle factors such as maturation-promoting factor, impair calcium homoeostasis, induce mitochondrial dysfunction and directly damage multiple intracellular components of the oocyte such as lipids, proteins and DNA. Finally, this review addresses current strategies for delaying post-ovulatory oocyte ageing with a particular focus on the potential use of compounds such as caffeine or selected antioxidants in the development of more refined media for the preservation of oocyte integrity during IVF procedures.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Fujie Yan ◽  
Yushu Chen ◽  
Ramila Azat ◽  
Xiaodong Zheng

Mulberry anthocyanins possess many pharmacological effects including liver protection, anti-inflammation, and anticancer. The aim of this study was to evaluate whether mulberry anthocyanin extract (MAE) exerts beneficial effects against oxidative stress damage in HepG2 cells and Caenorhabditis elegans. In vitro, MAE prevented cytotoxicity, increased glucose consumption and uptake, and eliminated excessive intracellular free radicals in H2O2-induced cells. Moreover, MAE pretreatment maintained Nrf2, HO-1, and p38 MAPK stimulation and abolished upregulation of p-JNK, FOXO1, and PGC-1α that were involved in oxidative stress and insulin signalling modulation. In vivo, extended lifespan was observed in C. elegans damaged by paraquat in the presence of MAE, while these beneficial effects were disappeared in pmk-1 and daf-16 mutants. PMK-1 and SKN-1 were activated after exposure to paraquat and MAE suppressed PMK-1 activation but enhanced SKN-1 stimulation. Our findings suggested that MAE recovered redox status in HepG2 cells and C. elegans that suffered from oxidative stress, which might be by targeting MAPKs and Nrf2.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fan Yang ◽  
Lingqing Xu ◽  
Lujie Liang ◽  
Wanfei Liang ◽  
Jiachen Li ◽  
...  

Type I and type II CRISPR-Cas systems are employed to evade host immunity by targeting interference of bacteria’s own genes. Although Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, possesses integrated type III-A CRISPR-Cas system, its role in mycobacteria remains obscure. Here, we observed that seven cas genes (csm2∼5, cas10, cas6) were upregulated in Mycobacterium bovis BCG under oxidative stress treatment, indicating the role of type III-A CRISPR-Cas system in oxidative stress. To explore the functional role of type III-A CRISPR-Cas system, TCC (Type III-A CRISPR-Cas system, including cas6, cas10, and csm2-6) mutant was generated. Deletion of TCC results in increased sensitivity in response to hydrogen peroxide and reduced cell envelope integrity. Analysis of RNA-seq dataset revealed that TCC impacted on the oxidation-reduction process and the composition of cell wall which is essential for mycobacterial envelop integrity. Moreover, disrupting TCC led to poor intracellular survival in vivo and in vitro. Finally, we showed for the first time that TCC contributed to the regulation of regulatory T cell population, supporting a role of TCC in modulating host immunity. Our finding reveals the important role of TCC in cell envelop homeostasis. Our work also highlights type III-A CRISPR-Cas system as an important factor for intracellular survival and host immunoregulation in mycobacteria, thus may be a potential target for therapy.


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