scholarly journals Saponins fromAralia taibaiensisAttenuate D-Galactose-Induced Aging in Rats by Activating FOXO3a and Nrf2 Pathways

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Ying-Na Li ◽  
Yu Guo ◽  
Miao-Miao Xi ◽  
Pei Yang ◽  
Xue-Ying Zhou ◽  
...  

Reactive oxygen species (ROS) are closely related to the aging process. In our previous studies, we found that the saponins fromAralia taibaiensishave potent antioxidant activity, suggesting the potential protective activity on the aging. However, the protective effect of the saponins and the possible underlying molecular mechanism remain unknown. In the present study, we employed a D-galactose-induced aging rat model to investigate the protective effect of the saponins. We found that D-galactose treatment induced obvious aging-related changes such as the decreased thymus and spleen coefficients, the increased advanced glycation end products (AGEs) level, senescence-associatedβ-galactosidase (SAβ-gal) activity, and malondialdehyde (MDA) level. Further results showed that Forkhead box O3a (FOXO3a), nuclear factor-erythroid 2-related factor 2 (Nrf2), and their targeted antioxidants such as superoxide dismutase 2 (SOD2), catalase (CAT), glutathione reductase (GR), glutathione (GSH), glutamate-cysteine ligase (GCL), and heme oxygenase 1 (HO-1) were all inhibited in the aging rats induced by D-galactose treatment. Saponins supplementation showed effective protection on these changes. These results demonstrate that saponins fromAralia taibaiensisattenuate the D-galactose-induced rat aging. By activating FOXO3a and Nrf2 pathways, saponins increase their downstream multiple antioxidants expression and function, at least in part contributing to the protection on the D-galactose-induced aging in rats.

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 380 ◽  
Author(s):  
Huang ◽  
Chang ◽  
Chau ◽  
Chiu

Hispidin, a polyphenol compound isolated from Phellinus linteus, has been reported to possess antioxidant activities. In this study, we aimed to investigate the mechanisms underlying the protective effect of hispidin against hydrogen peroxide (H2O2)-induced oxidative stress on Adult Retinal Pigment Epithelial cell line-19 (ARPE-19) cells. Hispidin was not cytotoxic to ARPE-19 cells at concentrations of less than 50 μM. The levels of intracellular reactive oxygen species (ROS) were analyzed by dichlorofluorescin diacetate (DCFDA) staining. Hispidin significantly restored H2O2-induced cell death and reduced the levels of intracellular ROS. The expression levels of antioxidant enzymes, such as NAD(P)H:Quinine oxidoreductase-1 (NQO-1), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutamate-cysteine ligase modifier subunit (GCLM) were examined using real-time PCR and Western blotting. Our results showed that hispidin markedly enhanced the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), HO-1, NQO-1, GCLM, and GCLC in a dose-dependent manner. Furthermore, knockdown experiments revealed that transfection with Nrf2 siRNA successfully suppresses the hispidin activated Nrf2 signaling in ARPE-19 cells. Moreover, activation of the c-Jun N-terminal kinase (JNK) pathway is involved in mediating the protective effects of hispidin on the ARPE-19 cells. Thus, the present study demonstrated that hispidin provides protection against H2O2-induced damage in ARPE-19 cells via activation of Nrf2 signaling and up-regulation of its downstream targets, including Phase II enzymes, which might be associated with the activation of the JNK pathway.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Guosheng Lin ◽  
Dandan Luo ◽  
Jingjing Liu ◽  
Xiaoli Wu ◽  
Jinfen Chen ◽  
...  

The effect of polysaccharides isolated from Dendrobium officinale (DOP) on acetaminophen- (APAP-) induced hepatotoxicity and the underlying mechanisms involved are investigated. Male Institute of Cancer Research (ICR) mice were randomly assigned to six groups: (1) control, (2) vehicle (APAP, 230 mg/kg), (3) N-acetylcysteine (100 mg/kg), (4) 50 mg/kg DOP, (5) 100 mg/kg DOP, and (6) 200 mg/kg DOP. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in the serum and glutathione (GSH), malondialdehyde (MDA), catalase (CAT), total antioxidant capacity (T-AOC), myeloperoxidase (MPO), and reactive oxygen species (ROS) levels in the liver were determined after the death of the mice. The histological examination of the liver was also performed. The effect of DOP on the Kelch-like ECH-associated protein 1- (Keap1-) nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway was evaluated using Western blot analysis and real-time polymerase chain reaction (PCR). The results showed that DOP treatment significantly alleviated the hepatic injury. The decrease in ALT and AST levels in the serum and ROS, MDA, and MPO contents in the liver, as well as the increases in GSH, CAT, and T-AOC in the liver, were observed after DOP treatment. DOP treatment significantly induced the dissociation of Nrf2 from the Nrf2−Keap1 complex and promoted the Nrf2 nuclear translocation. Subsequently, DOP-mediated Nrf2 activation triggered the transcription and expressions of the glutamate–cysteine ligase catalytic (GCLC) subunit, glutamate–cysteine ligase regulatory subunit (GCLM), heme oxygenase-1 (HO-1), and NAD(P)H dehydrogenase quinone 1 (NQO1) in APAP-treated mice. The present study revealed that DOP treatment exerted potentially hepatoprotective effects against APAP-induced liver injury. Further investigation about mechanisms indicated that DOP exerted the hepatoprotective effect by suppressing the oxidative stress and activating the Nrf2−Keap1 signaling pathway.


2016 ◽  
Vol 94 (5) ◽  
pp. 517-525 ◽  
Author(s):  
Jinlian Li ◽  
Yanli Zhang ◽  
Haiyun Luan ◽  
Xuehong Chen ◽  
Yantao Han ◽  
...  

In our previous study, l-carnitine was shown to have cytoprotective effect against hydrogen peroxide (H2O2)-induced injury in human normal HL7702 hepatocytes. The aim of this study was to investigate whether the protective effect of l-carnitine was associated with the nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) pathway. Our results showed that pretreatment with l-carnitine augmented Nrf2 nuclear translocation, DNA binding activity and heme oxygenase-1 (HO-1) expression in H2O2-treated HL7702 cells, although l-carnitine treatment alone had no effect on them. Analysis using Nrf2 siRNA demonstrated that Nrf2 activation was involved in l-carnitine-induced HO-1 expression. In addition, l-carnitine-mediated protection against H2O2 toxicity was abrogated by Nrf2 siRNA, indicating the important role of Nrf2 in l-carnitine-induced cytoprotection. Further experiments revealed that l-carnitine pretreatment enhanced the phosphorylation of Akt in H2O2-treated cells. Blocking Akt pathway with inhibitor partly abrogated the protective effect of l-carnitine. Moreover, our finding demonstrated that the induction of Nrf2 translocation and HO-1 expression by l-carnitine directly correlated with the Akt pathway because Akt inhibitor showed inhibitory effects on the Nrf2 translocation and HO-1 expression. Altogether, these results demonstrate that l-carnitine protects HL7702 cells against H2O2-induced cell damage through Akt-mediated activation of Nrf2 signaling pathway.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Hongming Lv ◽  
Hua Ren ◽  
Lidong Wang ◽  
Wei Chen ◽  
Xinxin Ci

Licochalcone A (Lico A) exhibits various biological properties, including anti-inflammatory and antioxidant activities. In this study, we investigated the antioxidative potential and mechanisms of Lico A againsttert-butyl hydroperoxide- (t-BHP-) induced oxidative damage in RAW 264.7 cells. Our results indicated that Lico A significantly inhibitedt-BHP-induced cytotoxicity, apoptosis, and reactive oxygen species (ROS) generation and reduced glutathione (GSH) depletion but increased the glutamate-cysteine ligase modifier (GCLM) subunit and the glutamate-cysteine ligase catalytic (GCLC) subunit genes expression. Additionally, Lico A dramatically upregulated the antioxidant enzyme heme oxygenase 1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2), which were associated with inducing Nrf2 nuclear translocation, decreasing Keap1 protein expression and increasing antioxidant response element (ARE) promoter activity. Lico A also obviously induced the activation of serine/threonine kinase (Akt) and extracellular signal-regulated kinase (ERK), but PI3K/Akt and ERK inhibitors treatment displayed clearly decreased levels of LicoA-induced Nrf2 nuclear translocation and HO-1 expression, respectively. Furthermore, Lico A treatment markedly attenuatedt-BHP-induced oxidative damage, which was reduced by treatment with PI3K/Akt, ERK, and HO-1 inhibitors. Therefore, Lico A might have a protective role againstt-BHP-induced cytotoxicity by modulating HO-1 and by scavenging ROS via the activation of the PI3K/Akt and ERK/Nrf2 signaling pathways.


2022 ◽  
Vol 20 (2) ◽  
pp. 275-280
Author(s):  
Lei Ji ◽  
Xue Zhong ◽  
Xingxing Xia ◽  
Wei Yu ◽  
Yuping Qin

Purpose: To investigate the protective role of syringaresinol in a rat model of diabetic nephropathy (DN). Methods: Streptozotocin was injected intraperitoneally into rats to establish the diabetic model. Streptozotocin-induced rats were orally administered syringaresinol, and pathological changes in kidneys were assessed using hematoxylin and eosin staining. Enzyme-linked immunosorbent assay (ELISA) was used to determine kidney injury indicators, 24-h urine proteins, blood urea nitrogen (BUN), and serum creatinine (SCR). Blood glucose was measured using a blood glucose meter, while levels of malonaldehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) in kidney were also measured using ELISA. Results: Pathological changes in the kidneys were observed in rats post-streptozotocin treatment. Administration of syringaresinol reduced the lesion degree, with improved pathological morphology in kidney. Syringaresinol administration significantly attenuated streptozotocin-increased levels of BUN, SCR, 24-h urine protein, and blood glucose (p < 0.01). Streptozotocin-induced oxidative stress, shown by enhanced MDA level and reduced levels of SOD, CAT, and GSH-PX, was reversed in rat kidneys following syringaresinol administration. However, the expression levels of nuclear factor erythropoietin- 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) proteins decreased, while transforming growth factor-beta 1 (TGF-β1) and signal transducer and transcriptional modulator (Smad) 2/3/7 proteins increased in rats post-streptozotocin treatment. Syringaresinol administration reversed the effects of streptozotocin on protein expression of Nrf2, HO-1, TGF-β1, and Smad 2/3/7. Conclusion: Syringaresinol exerted a protective effect against DN through activation of Nrf2 and inactivation of TGF-β1/Smad pathways. Thus, the compound can potentially be developed for management of diabetic nephropathy.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Si Huang ◽  
Haiyan Yuan ◽  
Wenqun Li ◽  
Xinyi Liu ◽  
Xiaojie Zhang ◽  
...  

Polygonatum sibiricum, a well-known life-prolonging tonic in Chinese medicine, has been widely used for nourishing nerves in the orient, but the underlying molecular mechanisms remain unclear. In this study, we found that P. sibiricum polysaccharides (PSP) ameliorated 1-methyl-4-phenyl-1,2.3,6-tetrahydropyridine- (MPTP-) induced locomotor activity deficiency and dopaminergic neuronal loss in an in vivo Parkinson’s disease (PD) mouse model. Additionally, PSP pretreatment inhibited N-methyl-4-phenylpyridine (MPP+) induced the production of reactive oxygen species, increasing the ratio of reduced glutathione/oxidized glutathione. In vitro experiments showed that PSP promoted the proliferation of N2a cells in a dose-dependent manner, while exhibiting effects against oxidative stress and neuronal apoptosis elicited by MPP+. These effects were found to be associated with the activation of Akt/mTOR-mediated p70S6K and 4E-BP1 signaling pathways, as well as nuclear factor erythroid 2-related factor 2- (Nrf2-) mediated NAD(P)H quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (Gclc), and glutamate-cysteine ligase modulatory subunit (Gclm), resulting in antiapoptotic and antioxidative effects. Meanwhile, PSP exhibited no chronic toxicity in C57BJ/6 mice. Together, our results suggest that PSP can serve as a promising therapeutic candidate with neuroprotective properties in preventing PD.


Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 167
Author(s):  
Seyed Hossein Shahcheraghi ◽  
Fateme Salemi ◽  
Niloufar Peirovi ◽  
Jamshid Ayatollahi ◽  
Waqas Alam ◽  
...  

Nuclear factor erythroid 2 p45-related factor (2Nrf2) is an essential leucine zipper protein (bZIP) that is primarily located in the cytoplasm under physiological conditions. Nrf2 principally modulates endogenous defense in response to oxidative stress in the brain.In this regard, Nrf2 translocates into the nucleus and heterodimerizes with the tiny Maf or Jun proteins. It then attaches to certain DNA locations in the nucleus, such as electrophile response elements (EpRE) or antioxidant response elements (ARE), to start the transcription of cytoprotective genes. Many neoplasms have been shown to have over activated Nrf2, strongly suggesting that it is responsible for tumors with a poor prognosis. Exactly like curcumin, Zinc–curcumin Zn (II)–curc compound has been shown to induce Nrf2 activation. In the cancer cell lines analyzed, Zinc–curcumin Zn (II)–curc compound can also display anticancer effects via diverse molecular mechanisms, including markedly increasing heme oxygenase-1 (HO-1) p62/SQSTM1 and the Nrf2 protein levels along with its targets. It also strikingly decreases the levels of Nrf2 inhibitor, Kelch-like ECH-associated protein 1 (Keap1) protein.As a result, the crosstalk between p62/SQSTM1 and Nrf2 could be used to improve cancer patient response to treatments. The interconnected anti-inflammatory and antioxidative properties of curcumin resulted from its modulatory effects on Nrf2 signaling pathway have been shown to improve insulin resistance. Curcumin exerts its anti-inflammatory impact through suppressing metabolic reactions and proteins such as Keap1 that provoke inflammation and oxidation. A rational amount of curcumin-activated antioxidant Nrf2 HO-1 and Nrf2-Keap1 pathways and upregulated the modifier subunit of glutamate-cysteine ligase involved in the production of the intracellular antioxidant glutathione. Enhanced expression of glutamate-cysteine ligase, a modifier subunit (GLCM), inhibited transcription of glutamate-cysteine ligase, a catalytic subunit (GCLC). A variety of in vivo, in vitro and clinical studies has been done so far to confirm the protective role of curcumin via Nrf2 regulation. This manuscript is designed to provide a comprehensive review on the molecular aspects of curcumin and its derivatives/analogs via regulation of Nrf2 regulation.


Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 977
Author(s):  
Nancy S. Younis ◽  
Mohamed S. Abduldaium ◽  
Maged E. Mohamed

Background: Myocardial infarction (MI) is still a major contributor to mortality worldwide, and therefore, searching for new drugs is an urgent priority. Natural products are a renewable source for medicinally and pharmacologically active molecules. The objective of this study was to explore the potential of geraniol, a monoterpene alcohol, to protect against MI. Methods: Five groups of Wister rats were used: a control group; a group treated only with geraniol; a group treated only with isoproterenol, to induce MI; and two groups pretreated with geraniol (100 or 200 mg/kg, respectively) for 14 days and challenged with isoproterenol on the 13th and 14th days. Several parameters were measured including electrocardiogram (ECG), cardiac markers, the expression of Kelch-like ECH-associated protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), and other downstream antioxidant enzymes, as well as the expression of phosphoinositide 3-kinases (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and other downstream apoptotic and inflammatory mediators. Results: Geraniol treatment reduced the size of the infarct region, attenuated the levels of cardiac indicators, and diminished myocardial necrosis and immune cell infiltration. Geraniol treatment also activated the Keap1/Nrf2/heme oxygenase-1 (HO-1) pathway, increased antioxidant enzyme activities, modulated the PI3K/Akt/mTOR pathway, and ameliorated myocardial autophagy, inflammation, and apoptosis. Conclusion: Geraniol may possess a protective effect against MI through moderating MI-induced myocardial oxidative stress (glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), and Keap1/Nrf2 pathway), inflammation (IL-1β, IL-6, TNF-α, and Nuclear factor-κB (NF-κB)), apoptosis (caspase-3, caspase-9, Bcl2, and Bax), and autophagy (PI3K/Akt/mTOR pathway).


2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Wenwen Li ◽  
Fenfen Ma ◽  
Laiyin Zhang ◽  
Yong Huang ◽  
Xinghui Li ◽  
...  

This study investigated the antioxidative effect of S-propargyl-cysteine (SPRC) on nonalcoholic fatty liver (NAFLD) by treating mice fed a methionine and choline deficient (MCD) diet with SPRC for four weeks. We found that SPRC significantly reduced hepatic reactive oxygen species (ROS) and methane dicarboxylic aldehyde (MDA) levels. Moreover, SPRC also increased the superoxide dismutase (SOD) activity. By Western blot, we found that this protective effect of SPRC was importantly attributed to the regulated hepatic antioxidant-related proteins, including protein kinase B (Akt), heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and cystathionineγ-lyase (CSE, an enzyme that synthesizes hydrogen sulfide). Next, we examined the detailed molecular mechanism of the SPRC protective effect using oleic acid- (OA-) induced HepG2 cells. The results showed that SPRC significantly decreased intracellular ROS and MDA levels in OA-induced HepG2 cells by upregulating the phosphorylation of Akt, the expression of HO-1 and CSE, and the translocation of Nrf2. SPRC-induced HO-1 expression and Nrf2 translocation were abolished by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002. Moreover, the antioxidative effect of SPRC was abolished by CSE inhibitor DL-propargylglycine (PAG) and HO-1 siRNA. Therefore, these results proved that SPRC produced an antioxidative effect on NAFLD through the PI3K/Akt/Nrf2/HO-1 signaling pathway.


Sign in / Sign up

Export Citation Format

Share Document