Qing-Chun Zhao

Neuroprotective effects of Kukoamine B against hydrogen peroxide-induced apoptosis and potential mechanisms in SH-SY5Y cells

Oxidative stress mediates the cell damage in several neurodegenerative diseases, including multiple sclerosis, Alzheimers disease (AD) and Parkinsons disease (PD). This study aimed at investigating the protective effects of Kukoamine B (KuB) against hydrogen peroxide (H2O2) induced cell injury and potential mechanisms in SH-SY5Y cells. Our results revealed that treatment with KuB prior to H2O2 exposure effectively increased the cell viability, and restored the mitochondria membrane potential (MMP). Furthermore, KuB enhanced the antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and decreased the malondialdehyde (MDA) content. Moreover, KuB minimized the ROS formation and inhibited mitochondria-apoptotic pathway, MAPKs (p-p38, p-JNK, p-ERK) pathways, but activated PI3K-AKT pathway. In conclusion, we believed that KuB may potentially serve as an agent for prevention of several human neurodegenerative and other disorders caused by oxidative stress.

Neuroprotection by Kukoamine A against oxidative stress may involve N-methyl-D-aspartate receptors.

BACKGROUND Accumulative evidences have indicated that oxidative-stress and over-activation of N-methyl-d-aspartate receptors (NMDARs) are important mechanisms of brain injury. This study investigated the neuroprotection of Kukoamine A (KuA) and its potential mechanisms. METHODS Molecular docking was used to discover KuA that might have the ability of blocking NMDARs. Furthermore, the MTT assay, the measurement of LDH, SOD and MDA, the flow cytometry for ROS, MMP and Annexin V-PI double staining, the laser confocal microscopy for intracellular Ca2+ and western-blot analysis were employed to evaluate the neuroprotection of KuA. RESULTS KuA attenuated H2O2-induced cell apoptosis, LDH release, ROS production, MDA level, MMP loss, and intracellular Ca2+ overload (both induced by H2O2 and NMDA), as well as increased the SOD activity. In addition, it could modulate the apoptosis-related proteins (Bax, Bcl-2, p53, procaspase-3 and procaspase-9), the SAPKs (ERK, p38), AKT, CREB, NR2A and NR2B expression. CONCLUSIONS All the results indicated that KuA has the ability of anti-oxidative stress and this effect may partly via blocking NMDARs in SH-SY5Y cells. GENERAL SIGNIFICANCE KuA might have the potential therapeutic interventions for brain injury.

Neuroprotective effects of Arctium lappa L. roots against glutamate-induced oxidative stress by inhibiting phosphorylation of p38, JNK and ERK 1/2 MAPKs in PC12 cells

Many studies have shown that glutamate-induced oxidative stress can lead to neuronal cell death involved in the development of neurodegenerative diseases. In this work, protective effects of ethyl acetate extract (EAE) of Arctium lappa L. roots against glutamate-induced oxidative stress in PC12 cells were evaluated. Also, the effects of EAE on antioxidant system, mitochondrial pathway, and signal transduction pathway were explored. Pretreatment with EAE significantly increased cell viability, activities of GSH-Px and SOD, mitochondrial membrane potential and reduced LDH leakage, ROS formation, and nuclear condensation in a dose-dependent manner. Furthermore, western blot results revealed that EAE increased the Bcl-2/Bax ratio, and inhibited the up-regulation of caspase-3, release of cytochrome c, phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK 1/2). Therefore, our results indicate that EAE may be a promising neuroprotective agent for the prevention and treatment of neurodegenerative diseases implicated with oxidative stress.

Neuroprotective effects of Kukoamine A on neurotoxin-induced Parkinson's model through apoptosis inhibition and autophagy enhancement

&NA; Parkinsons disease (PD) is characterized by the loss of dopaminergic neurons in substantia nigra (SN). Our previous study demonstrated Kukoamine A to exhibit strong neuroprotective effects through anti‐oxidative stress, anti‐inflammation, anti‐excitoxicity. In the present study, MPP+ and MPTP‐induced PD models of cell and animal were used to investigate the effects of KuA on PD. Our results demonstrated that KuA ameliorated cell loss and mitochondrial membrane potential (MMP) loss, and inhibited Bax/Bcl‐2 ratio and MAPKs family that were induced by MPP+. In addition, animal experiments showed that KuA improved the motor function and neuronal activity, and increased the positive cells of tyrosine hydroxylase (TH) both in substantia nigra (SN) and striatum (Str). Moreover, KuA could decrease the expression of &agr;‐synuclein in brain. Finally, KuA exerted apparent autophagy enhancement both in vitro and in vivo. In conclusion, KuA protected against neurotoxin‐induced PD due to the apoptosis inhibition and autophagy enhancement, suggesting that KuA treatment might represent a neuroprotective treatment for PD. Graphical abstract Figure. No caption available. HighlightsIt was the first time to report that KuA have effects on PD both in vitro and in vivo.It was the first time to report that KuA could induce autophagy both in vitro and in vivo.The action mechanisms of KuA on PD were involved in multiple signalling pathways.KuA might be a promising neuroprotective agent for the prevention of PD.

Kukoamine B, an amide alkaloid, protects against NMDA-induced neurotoxicity and potential mechanisms in vitro

A major cause of cerebral ischemia is overactivation of the N-methyl-D-aspartate receptors (NMDARs). Therefore, NMDAR antagonists are needed for the treatment of cerebral ischemia. In our research, KuB protected the SH-SY5Y cells against NMDA-induced injury, apoptosis, LDH release and MMP loss. In addition, KuB could decrease MDA levels while increasing SOD activity. Meanwhile, KuB decreased NADPH oxidase-mediated ROS production, inhibited Ca(2+) influx, and increased the Bcl-2/Bax ratio. Furthermore, KuB not only down-regulated expression of the NR2B subunit of NMDAR but also actively modulated expression of the signaling molecules downstream of NR2B, including p-ERK, p-CREB, p-AKT and SAPKs. Finally, docking results showed that KuB had a high affinity for NR2B-containing NMDARs. Therefore, we conclude that KuB protected the SH-SY5Y cells from NMDA-induced injury likely by antagonizing NMDARs and reducing oxidative stress.

Effect of active fraction of Eriocaulon sieboldianum on human leukemia K562 cells via proliferation inhibition, cell cycle arrest and apoptosis induction

Eriocaulon sieboldianum (Sieb. & Zucc. ex Steud.), a genus of Eriocaulon in the Eriocaulaceae family, is an edible and medicinal plant used in traditional Chinese medicine. It was processed into healthcare beverages for expelling wind-heat, protecting eyes, and reducing blood fat. Also, it has been used with other herbs as Traditional Chinese herbal compound to treat cancer as adjuvants in tumor therapy in China. However, the active fractions and precise cellular mechanisms of E. sieboldianum extract remain to be illustrated. The goal of this study was to investigate the effects of the active fraction of E. sieboldianum on the growth of K562 cells and understand the possible mechanisms of its action. Our findings suggested that the fraction E3 of E. sieboldianum could effectively inhibit the activity of Aurora kinase and induce apoptosis via blocking cell cycle, up-regulating the expression of proapoptotic proteins including p53 and Bax and reducing the expression of Bcl-2. The levels of Cytochrome C, cleaved caspase-9, cleaved caspase-3 and cleaved PARP were also found to be increased after treatment with fraction E3 of E. sieboldianum. This study could improve the development of E. sieboldianum and raise its application value in cancer adjuvant therapy. Considering it is both a dietary supplement and a traditional Chinese herbal medicine which exhibits anticancer activities, it can be developed into functional food.

Neuroprotective effects of Kukoamine A against cerebral ischemia via antioxidant and inactivation of apoptosis pathway

ABSTRACT Kukoamine A (KuA) is a bioactive compound, which is known for a hypotensive effect. Recent studies have shown that KuA has anti‐oxidative effect and anti‐apoptosis stress in vitro. However, its neuroprotective effect in rats with cerebral ischemia is still unclear. In the study, we investigated whether KuA could attenuate cerebral ischemia induced by permanent middle cerebral artery occlusion (pMCAO) in rats. Results revealed that KuA could significantly reduce infarct volume both pre‐treatment and post‐treatment, and increase corresponding Garcia neurological scores. Acute KuA postconditioning not only significantly reduced cerebral infarct volume, brain water content and improved neurological deficit scores, but also decreased the number of TUNEL‐positive cells. Moreover, it markedly increased the activities of Cu/Zn‐SOD and Mn‐SOD, reduced levels of MDA and H2O2. Increased expressions of caspase‐3, cytochrome c and the ratio of Bax/Bcl‐2 were significantly alleviated with KuA treatment. These findings demonstrated that KuA was able to protect the brain against injury induced by pMCAO via mitochondria mediated apoptosis signaling pathway. HIGHLIGHTSKuA could reduce the infarct volume both in pre‐occlusion and post‐occlusion.KuA could attenuate brain swelling and the number of apoptotic cells in the ischemic brain.The potential mechanisms may be involved in modulating oxidative status and inactivation mitochondrial apoptosis pathway.

Erratum to: Caffeoylquinic Acid Derivatives Protect SH-SY5Y Neuroblastoma Cells from Hydrogen Peroxide-Induced Injury Through Modulating Oxidative Status

Oxidative stress has been confirmed as a contribution to the pathogenesis and pathophysiology of many neurological disorders such as Alzheimer’s disease and Parkinson’s disease. Caffeoylquinic acids (CQAs) are considered to have anti-oxidative stress ability in a previous study, but the structure–activity relationships (SARs) of CQAs in neuroprotective effects are still unclear. In the present study, we primarily expound the SARs of CQAs in counteracting H2O2-induced injury in SH-SY5Y cells. We found that CQAs (1–10) represented the protection of SH-SY5Y cells against H2O2-induced injury in varying degrees and malonyl groups could obviously increase the anti-oxidative stress ability of CQAs. Intensive studies of 4,5-O-dicaffeoyl-1-O-(malic acid methyl ester)-quinic acid (MDCQA) indicated that the mechanisms could potentially involve activation of endogenous antioxidant enzymes and the regulation of the phosphorylation of MAPKs and AKT. In conclusion, MDCQA could serve as a neuroprotective agent with a potential to attenuate oxidative stress.

Ethanol extract and its dichloromethane fraction of Alpinia oxyphylla Miquel exhibited hepatoprotective effects against CCl4-induced oxidative damage in vitro and in vivo with the involvement of Nrf2

Alpinia oxyphylla Miq. (A. oxyphylla), as a kind of medicine which also be used as food, is widely used in East Asian for the treatment of dyspepsia, diarrhea, abdominal pain and deficiency cold of spleen and stomach. This study aimed to investigate the protective effects of ethanol extract (EE) and its dichloromethane fraction (DM) of A. oxyphylla, which are rich in phenolic compounds, against CCl4-induced hepatic injury in vitro and in vivo. EE, DM and silymarin ameliorated CCl4-induced decrease of cell viability and increase of reactive oxygen species (ROS) in HepG2 cells. The CCl4-induced changes of glutathione (GSH) and methane dicarboxylic aldehyde (MDA) levels, and the decrease of superoxide dismutase (SOD) and catalase (CAT) activities were all restored with the pretreatment of EE, DM and silymarin. The results in liver injury model in rats showed that EE, DM and silymarin could significant decrease the levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin than the model group. Liver histopathology revealed that EE and DM attenuated the incidence of liver lesions triggered by CCl4 intoxication. They also effectively relieved CCl4-induced oxidative damage. Western blot analysis indicated NF-E2-related factor (Nrf2) pathway played an critical role in the protection of EE and DM against CCl4-induced oxidative stress. In conclusion, the extracts from A. oxyphylla might be used as hepatoprotective agents.

NSCA-1—a novel N-substituted coumalamide derivative—increases Adriamycin sensitivity in HepG2/adriamycin cells through modulating Akt/GSK-3β signaling and p53-dependant apoptotic pathway

Coumalamide derivatives are one of 2-pyrones derivatives, exerting multifunctional bioactivity. An array of coumalamide derivatives have been developed and presented good antiproliferative properties on cancer cells. However, the synthesis of 5-substituted coumalamide derivatives has not yet been published. Resistance to chemotherapeutic drugs is a major obstacle in hepatocellular carcinoma therapy. Recent evidence suggests that overexpression of constitutively active Akt confers on cancer cells resistance to chemotherapy. In this study, we report the synthesis and biological evaluation of a novel N-substituted coumalamide derivative (NSCA-1). The results indicated that NSCA-1 exerts synergistic cytotoxicity with Adriamycin in HepG2/ADR (HepG2/adriamycin) cells. Furthermore, both of the Akt kinase activity and phosphorylated Akt (Ser473) were found to be inhibited by NSCA-1 and subsequently resulting in decreased phosphorylation of GSK-3β. The intracellular accumulation of Adriamycin was also boosted by NSCA-1 via reducing the expression of p-gp. In addition, we found that combined treatment with NSCA-1 enhance cell apoptosis induced by Adriamycin via p53-dependant apoptotic pathway.