Melatonin protects H9c2 cells against ischemia/reperfusion‑induced apoptosis and oxidative stress via activation of the Nrf2 signaling pathway

The cardioprotective effect of sevoflurane postconditioning (SPostC) is lost in diabetes that is associated with cardiac phosphatase and tensin homologue on chromosome 10 (PTEN) activation and phosphoinositide 3-kinase (PI3K)/Akt inactivation. T-LAK cell-originated protein kinase (TOPK), a mitogen-activated protein kinase- (MAPKK-) like serine/threonine kinase, has been shown to inactivate PTEN (phosphorylated status), which in turn activates the PI3K/Akt signaling (phosphorylated status). However, the functions of TOPK and molecular mechanism underlying SPostC cardioprotection in nondiabetes but not in diabetes remain unknown. We presumed that SPostC exerts cardioprotective effects by activating PTEN/PI3K/Akt through TOPK in nondiabetes and that impairment of TOPK/PTEN/Akt blocks diabetic heart sensitivity to SPostC. We found that in the nondiabetic C57BL/6 mice, SPostC significantly attenuated postischemic infarct size, oxidative stress, and myocardial apoptosis that was accompanied with enhanced p-TOPK, p-PTEN, and p-Akt. These beneficial effects of SPostC were abolished by either TOPK kinase inhibitor HI-TOPK-032 or PI3K/Akt inhibitor LY294002. Similarly, SPostC remarkably attenuated hypoxia/reoxygenation-induced cardiomyocyte damage and oxidative stress accompanied with increased p-TOPK, p-PTEN, and p-Akt in H9c2 cells exposed to normal glucose, which were canceled by either TOPK inhibition or Akt inhibition. However, either in streptozotocin-induced diabetic mice or in H9c2 cells exposed to high glucose, the cardioprotective effect of SPostC was canceled, accompanied by increased oxidative stress, decreased TOPK phosphorylation, and impaired PTEN/PI3K/Akt signaling. In addition, TOPK overexpression restored posthypoxic p-PTEN and p-Akt and decreased cell death and oxidative stress in H9c2 cells exposed to high glucose, which was blocked by PI3K/Akt inhibition. In summary, SPostC prevented myocardial ischemia/reperfusion injury possibly through TOPK-mediated PTEN/PI3K/Akt activation and impaired activation of this signaling pathway may be responsible for the loss of SPostC cardioprotection by SPostC in diabetes.

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Luteolin Alleviates AflatoxinB1-Induced Apoptosis and Oxidative Stress in the Liver of Mice through Activation of Nrf2 Signaling Pathway

Antioxidants ◽

10.3390/antiox10081268 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1268

Author(s):

Shahid Ali Rajput ◽

Aftab Shaukat ◽

Kuntan Wu ◽

Imran Rashid Rajput ◽

Dost Muhammad Baloch ◽

...

Keyword(s):

Oxidative Stress ◽

Liver Injury ◽

Signaling Pathway ◽

Aflatoxin B1 ◽

Physiological Saline ◽

Protective Effects ◽

Biochemical Alterations ◽

Protein Levels ◽

Nrf2 Signaling Pathway ◽

Induced Apoptosis

Aflatoxin B1 (AFB1), a threatening mycotoxin, usually provokes oxidative stress and causes hepatotoxicity in animals and humans. Luteolin (LUTN), well-known as an active phytochemical agent, acts as a strong antioxidant. This research was designed to investigate whether LUTN exerts protective effects against AFB1-induced hepatotoxicity and explore the possible molecular mechanism in mice. A total of forty-eight mice were randomly allocated following four treatment groups (n = 12): Group 1, physiological saline (CON). Group 2, treated with 0.75 mg/kg BW aflatoxin B1 (AFB1). Group 3, treated with 50 mg/kg BW luteolin (LUTN), and Group 4, treated with 0.75 mg/kg BW aflatoxin B1 + 50 mg/kg BW luteolin (AFB1 + LUTN). Our findings revealed that LUTN treatment significantly alleviated growth retardation and rescued liver injury by relieving the pathological and serum biochemical alterations (ALT, AST, ALP, and GGT) under AFB1 exposure. LUTN ameliorated AFB1-induced oxidative stress by scavenging ROS and MDA accumulation and boosting the capacity of the antioxidant enzyme (CAT, T-SOD, GSH-Px and T-AOC). Moreover, LUTN treatment considerably attenuates the AFB1-induced apoptosis in mouse liver, as demonstrated by declined apoptotic cells percentage, decreased Bax, Cyt-c, caspase-3 and caspase-9 transcription and protein with increased Bcl-2 expression. Notably, administration of LUTN up-regulated the Nrf2 and its associated downstream molecules (HO-1, NQO1, GCLC, SOD1) at mRNA and protein levels under AFB1 exposure. Our results indicated that LUTN effectively alleviated AFB1-induced liver injury, and the underlying mechanisms were associated with the activation of the Nrf2 signaling pathway. Taken together, LUTN may serve as a potential mitigator against AFB1-induced liver injury and could be helpful for the development of novel treatment to combat liver diseases in humans and/or animals.

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Geraniol activates Nrf-2/HO-1 signaling pathway mediating protection against oxidative stress-induced apoptosis in hepatic ischemia-reperfusion injury

Naunyn-Schmiedeberg s Archives of Pharmacology ◽

10.1007/s00210-020-01887-1 ◽

2020 ◽

Vol 393 (10) ◽

pp. 1849-1858

Author(s):

Soad Z. El-Emam ◽

Ayman A. Soubh ◽

Asmaa K. Al-Mokaddem ◽

Dina M. Abo El-Ella

Keyword(s):

Oxidative Stress ◽

Reperfusion Injury ◽

Signaling Pathway ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Hepatic Ischemia ◽

Hepatic Ischemia Reperfusion ◽

Induced Apoptosis

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Curcumin Protects Human Trophoblast HTR8/SVneo Cells from H2O2-Induced Oxidative Stress by Activating Nrf2 Signaling Pathway

Antioxidants ◽

10.3390/antiox9020121 ◽

2020 ◽

Vol 9 (2) ◽

pp. 121 ◽

Cited By ~ 6

Author(s):

Lina Qi ◽

Jingle Jiang ◽

Jingfei Zhang ◽

Lili Zhang ◽

Tian Wang

Keyword(s):

Oxidative Stress ◽

Oxidative Damage ◽

Signaling Pathway ◽

Protective Effects ◽

Human Trophoblast ◽

Nrf2 Signaling Pathway ◽

Antioxidant Proteins ◽

Pre Treatment ◽

Induced Apoptosis ◽

Excessive Accumulation

Pregnancy complications are associated with oxidative stress induced by accumulation of trophoblastic ROS in the placenta. We employed the human trophoblast HTR8/SVneo cell line to determine the effect of curcumin pre-treatment on H2O2-induced oxidative damage in HTR8/Sveo cells. Cells were pretreated with 2.5 or 5 μM curcumin for 24 h, and then incubated with 400 μM H2O2 for another 24 h. The results showed that H2O2 decreased the cell viability and induced excessive accumulation of reactive oxygen species (ROS) in HTR8/Sveo cells. Curcumin pre-treatment effectively protected HTR8/SVneo cells against oxidative stress-induced apoptosis via increasing Bcl-2/Bax ratio and decreasing the protein expression level of cleaved-caspase 3. Moreover, curcumin pre-treatment alleviated the excessive oxidative stress by enhancing the activity of antioxidative enzymes. The antioxidant effect of curcumin was achieved by activating Nrf2 and its downstream antioxidant proteins. In addition, knockdown of Nrf2 by Nrf2-siRNA transfection abolished the protective effects of curcumin on HTR8/SVneo cells against oxidative damage. Taken together, our results show that curcumin could protect HTR8/SVneo cells from H2O2-induced oxidative stress by activating Nrf2 signaling pathway.

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