scholarly journals The Potential of Lactobacillus spp. for Modulating Oxidative Stress in the Gastrointestinal Tract

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 610 ◽  
Author(s):  
Yanzhuo Kong ◽  
Kenneth J. Olejar ◽  
Stephen L. W. On ◽  
Venkata Chelikani

The gastrointestinal (GI) tract is crucial for food digestion and nutrient absorption in humans. However, the GI tract is usually challenged with oxidative stress that can be induced by various factors, such as exogenous pathogenic microorganisms and dietary alterations. As a part of gut microbiota, Lactobacillus spp. play an important role in modulating oxidative stress in cells and tissues, especially in the GI tract. Oxidative stress is linked with excessive reactive oxygen species (ROS) that can be formed by a few enzymes, such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs). The redox mechanisms of Lactobacillus spp. may contribute to the downregulation of these ROS-forming enzymes. In addition, nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf-2) and nuclear factor kappa B (NF-κB) are two common transcription factors, through which Lactobacillus spp. modulate oxidative stress as well. As oxidative stress is closely associated with inflammation and certain diseases, Lactobacillus spp. could potentially be applied for early treatment and amelioration of these diseases, either individually or together with prebiotics. However, further research is required for revealing their mechanisms of action as well as their extensive application in the future.

2017 ◽  
Vol 235 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Ke Ke ◽  
Ok-Joo Sul ◽  
Soo-Wol Chung ◽  
Jae-Hee Suh ◽  
Hye-Seon Choi

Nucleotide-binding oligomerization domain-2 (NOD2) is a pattern recognition receptor of the innate immune system. It interacts with serine–threonine kinases to induce activation of nuclear factor κB (NF-κB), which is important for receptor activator of nuclear factor kappa-B ligand (RANKL) signaling. We tested the idea that NOD2 modulates bone metabolism via an action on osteoclasts (OCs). The absence of NOD2 reduced ovariectomy-induced bone loss in mice, and lowered the area and the activity of OCs, by impairing RANKL signaling. It also reduced the level of reactive oxygen species (ROS), as well as of NF-κB-DNA binding upon RANKL exposure. NOD2 was found to physically interact with nicotinamide adenine dinucleotide phosphate oxidase 1, and this led to increased production of ROS in OCs. Our data suggest that NOD2 contributes to bone loss in estrogen deficiency by elevating ROS levels in OCs.


2014 ◽  
Vol 34 (2) ◽  
pp. 145-152 ◽  
Author(s):  
B Shen ◽  
W Wang ◽  
L Ding ◽  
Y Sao ◽  
Y Huang ◽  
...  

Aim: This study aimed to determine whether nuclear factor erythroid 2-related factor 2 antagonized the oxidative stress induced by di- N-butylphthalate (DBP) in testicular Leydig cells. Methods: Mouse TM3 testicular Leydig cells were treated with Nrf2 knockdown (KD) or overexpression in the presence and absence of DBP. Oxidative profiles were examined. Nrf2 target antioxidant genes were studied, and the effects of Nrf2 inducer sulphoraphane (SFN) were tested. Results: DBP induced intracellular oxidative stress to a similar extent with Nrf2 KD. Expression and protein levels of Nrf2 were increased together with its target genes, namely heme oxygenase 1, nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 and peroxiredoxin 6, following DBP stimulation. Use of SFN not only restored the intracellular oxidative toxicity but also cell proliferation and testosterone secretion in response to DBP. Conclusion: Increased Nrf2 activity, for example, by SFN can effectively antagonize the oxidative stress in testicular Leydig cells caused by DBP.


2021 ◽  
Vol 12 ◽  
Author(s):  
Bin Pan ◽  
Lin Zheng ◽  
Jiawei Fang ◽  
Ye Lin ◽  
Hehuan Lai ◽  
...  

Osteoporosis is characterized by a decrease in bone mass and destruction of the bone microarchitecture, and it commonly occurs in postmenopausal women and the elderly. Overactivation of osteoclasts caused by the inflammatory response or oxidative stress leads to osteoporosis. An increasing number of studies have suggested that intracellular reactive oxygen species (ROS) are strongly associated with osteoclastogenesis. As a novel angiotensin (Ang) II receptor blocker (ARB), azilsartan was reported to be associated with the inhibition of intracellular oxidative stress processes. However, the relationship between azilsartan and osteoclastogenesis is still unknown. In this study, we explored the effect of azilsartan on ovariectomy-induced osteoporosis in mice. Azilsartan significantly inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-mediated osteoclastogenesis and downregulated the expression of osteoclast-associated markers (Nfatc1, c-Fos, and Ctsk) in vitro. Furthermore, azilsartan reduced RANKL-induced ROS production by increasing the expression of nuclear factor erythroid 2-related factor 2 (Nrf2). Mechanistically, azilsartan inhibited the activation of MAPK/NF-κB signaling pathways, while Nrf2 silencing reversed the inhibitory effect of azilsartan on MAPK/NF-κB signaling pathways. Consistent with the in vitro data, azilsartan administration ameliorated ovariectomy (OVX)-induced osteoporosis, and decreased ROS levels in vivo. In conclusion, azilsartan inhibited oxidative stress and may be a novel treatment strategy for osteoporosis caused by osteoclast overactivation.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9720
Author(s):  
Wen-Tao Zhou ◽  
Li-Bin Wang ◽  
Hao Yu ◽  
Kai-Kai Zhang ◽  
Li-Jian Chen ◽  
...  

Polychlorinated biphenyls (PCBs), particularly low chlorinated congeners in our environment, can induce human hepatotoxicity. However, the mechanisms by which PCBs cause hepatotoxicity remain elusive. Moreover, there are no effective treatments for this condition. In this study, 40 μM PCB52 was administered to rat (Brl-3A) and human hepatocytes (L-02) for 48 h following the N-acetylcysteine (NAC)/saline pretreatment. A significant decrease in cell viability was observed in PCB52-treated cells relative to the control. Besides, PCB52 significantly increased reactive oxygen species (ROS) levels and malondialdehyde (MDA) contents, suggesting induction of oxidative stress. The expression of Traf6, MyD88, and Tnf in Brl-3A cells and that of MYD88, TNF, and IL1B in L-02 cells were significantly upregulated by PCB52. Consistently, overexpression of TLR4, MyD88, Traf6, and NF-κB p65 proteins was observed in PCB52-treated cells, indicating activation of inflammatory responses. Nevertheless, no changes in kelch-like ECH-associated protein 1 (keap1), nuclear factor-erythroid 2-related factor (nrf2), and heme oxygenase-1 proteins were observed in PCB52-treated cells, indicating non-activation of the keap1/nrf2 pathway. Pretreatment with NAC significantly ameliorated PCB52 effects on cell viability, ROS levels, MDA contents and expression of inflammatory elements at both RNA and protein levels. However, no changes in keap1, nrf2 and HO-1 protein levels were detected following NAC pretreatment. Taken together, with non-activated keap1/nrf2 pathway, PCB52-induced oxidative stress and inflammatory responses could be responsible for its hepatotoxicity. These effects were effectively attenuated by NAC pretreatment, which scavenges ROS and dampens inflammatory responses. This study might provide novel strategies for the treatment of the PCBs-associated hepatotoxic effects.


Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 403 ◽  
Author(s):  
Jihua Chen ◽  
Yuji Li ◽  
Fuqiang Liu ◽  
De-Xing Hou ◽  
Jingjing Xu ◽  
...  

Microcystin-LR (MC-LR), a cyanotoxin produced by cyanobacteria, induces oxidative stress in various types of cells. Prodigiosin, a red linear tripyrrole pigment, has been recently reported to have antimicrobial, antioxidative, and anticancer properties. How prodigiosin reacts to reactive oxygen species (ROS) induced by MC-LR is still undetermined. This study aimed to examine the effect of prodigiosin against oxidative stress induced by MC-LR in HepG2 cells. Ros was generated after cells were treated with MC-LR and was significantly inhibited with treatment of prodigiosin. In prodigiosin-treated cells, the levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2-related phase II enzyme heme oxygenase-1 (HO-1) were increased. Besides, prodigiosin contributed to enhance nuclear Nrf2 level and repressed ubiquitination. Furthermore, prodigiosin promoted Nrf2 protein level and inhibited ROS in Nrf2 knocked down HepG2 cells. Results indicated that prodigiosin reduced ROS induced by MC-LR by enhancing Nrf2 translocation into the nucleus in HepG2 cells. The finding presents new clues for the potential clinical applications of prodigiosin for inhibiting MC-LR-induced oxidative injury in the future.


2021 ◽  
Author(s):  
Yu Ma ◽  
Siwen Li ◽  
Sixuan Tang ◽  
Shuzi Ye ◽  
Ningjuan Liang ◽  
...  

Abstract Hexavalent chromium [Cr(VI)] is a serious environmental pollutant and threatens human health. Although it has been confirmed that oxidative stress is the main mechanism of liver injury caused by Cr(VI) exposure, the related toxic target and effective intervention measures have not been found. Clusterin (CLU) is an acute phase response protein with cytoprotective and apoptosis delaying effects, and its expression has been confirmed to increase significantly after exposure to Cr(VI). In this study, we demonstrate that CLU acts on the Protein Kinase B (PKB/Akt)-Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor E2-related factor 2 (Nrf2) signaling pathway to release Nrf2 into the nucleus. This to initiates the expression of a downstream protein, heme oxygenase 1 (HO-1), thereby attenuating the ubiquitination ability of Keap1 with Nrf2. We also demonstrated that CLU can affect oxidative stress through the Akt/Nrf2 pathway, which reduces the production of reactive oxygen species (ROS) induced by Cr(VI) and protects against Cr(VI)-induced oxidative stress-associated hepatotoxicity. This study demonstrates a the mechanism of Cr(VI)-induced hepatotoxicity, and indicates that CLU as an intervention target of oxidative stress can provide valuable experimental basis for the prevention and treatment of occupational diseases in Cr(VI)-exposed population.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1016
Author(s):  
Feijie Zhao ◽  
Xinxin Ci ◽  
Xiaxia Man ◽  
Jiajia Li ◽  
Zhentong Wei ◽  
...  

Oxidative stress, which refers to unbalanced accumulation of reactive oxygen species (ROS) levels in cells, has been linked to acute and chronic diseases. Nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) pathway plays a vital role in regulating cytoprotective genes and enzymes in response to oxidative stress. Therefore, pharmacological regulation of Nrf2/ARE pathway is an effective method to treat several diseases that are mainly characterized by oxidative stress and inflammation. Natural products that counteract oxidative stress by modulating Nrf2 have contributed significantly to disease treatment. In this review, we focus on bioactive compounds derived from food that are Nrf2/ARE pathway regulators and describe the molecular mechanisms for regulating Nrf2 to exert favorable effects in experimental models of diseases.


2020 ◽  
Vol 19 (2) ◽  
pp. 133-138
Author(s):  
Wenyu Chen ◽  
Hui He

Trilobatin is a natural plant-derived glycosylated flavonoid that has been shown to exhibit multiple beneficial pharmacologic activities including protection of heart against H/R-induced cardiomyocyte injury. However, the molecular mechanisms underlying protection from H/R-induced cardiomyocyte injury remain unknown. Using H9C2 cells as a model, we examined the effect of trilobatin on H/R-induced cellular injury, apoptosis, and generation of reactive oxygen species. The results showed that trilobatin protected H9C2 cells not only from cell death and apoptosis, but also counteracted H/R-induced changes in malondialdehyde, superoxide dismutase, glutathione, and glutathione peroxidase. The evaluation of the mechanism underlying the effect of trilobatin on protection from H/R-induced cellular injury suggested changes in the regulation of nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway.


2020 ◽  
Vol 18 (3) ◽  
pp. 260-265
Author(s):  
Xu Lin ◽  
Zheng Xiaojun ◽  
Lv Heng ◽  
Mo Yipeng ◽  
Tong Hong

The purpose of this study was to evaluate the protective effect of swertiamarin on heart failure. To this end, a rat model of heart failure was established via left coronary artery ligation. Infarct size of heart tissues was determined using triphenyl tetrazolium chloride staining. Echocardiography was performed to evaluate cardiac function by the determination of ejection fraction, left ventricular internal dimension in diastole and left ventricular internal dimension in systole. The effect of swertiamarin on oxidative stress was evaluated via enzyme-linked immunosorbent assay. The mechanism was evaluated using western blot. Administration of swertiamarin reduced the infarct size of heart tissues in rat models with heart failure. Moreover, swertiamarin treatment ameliorated the cardiac function, increased ejection fraction and fractional shortening, decreased left ventricular internal dimension in diastole and left ventricular internal dimension in systole. Swertiamarin improved oxidative stress with reduced malondialdehyde, while increased superoxide dismutase, glutathione, and GSH peroxidase. Furthermore, nuclear-factor erythroid 2-related factor 2, heme oxygenase and NAD(P)H dehydrogenase (quinone 1) were elevated by swertiamarin treatment in heart tissues of rat model with heart failure. Swertiamarin alleviated heart failure through suppression of oxidative stress response via nuclear-factor erythroid 2-related factor 2/heme oxygenase-1 pathway providing a novel therapeutic strategy for heart failure.


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