cytochrome-c-t and peoniflorin

Paeoniflorin (PF), a bioactive monoterpene glucoside, has shown a variety of pharmacological effects such as anti-inflammation and autophagy modulation etc. In this study, we investigated whether and how PF exerted a protective effect against ischemic brain injury in vivo and in vitro. Primary rat cortical neurons underwent oxygen/glucose deprivation/reperfusion (OGD/R) for 90 min. We showed that after OGD/R, a short fragment of histone deacetylase 4 (HDAC4) produced by caspase3-mediated degradation was markedly accumulated in the nucleus and the activity of caspase3 was increased. Treatment with PF (100 nM, 1 μM) significantly improved the viability of cortical neurons after OGD/R. Furthermore, PF treatment could maintain HDAC4 intrinsic subcellular localization and reduce the caspase3 activity without changing the HDAC4 at the transcriptional level. PF treatment significantly reduced OGD/R-caused inhibition of transcriptional factor MEF2 expression and increased the expression of downstream proteins such as GDNF, BDNF, and Bcl-xl, thus exerting a great anti-apoptosis effect as revealed by TUNEL staining. The beneficial effects of PF were almost canceled in HDAC4 (D289E)-transfected PC12 cells after OGD/R. In addition, PF treatment reduced the caspase9 activity, rescued the release of cytochrome c from mitochondria, and maintained the integrity of mitochondria membrane. We conducted in vivo experiments in 90-min-middle cerebral artery occlusion (MCAO) rat model. The rats were administered PF (20, 40 mg/kg, ip, 3 times at the reperfusion, 24 h and 48 h after the surgery). We showed that PF administration dose-dependently reduced infarction area, improved neurological symptoms, and maintained HDAC4 localization in rats after MCAO. These results demonstrate that PF is effective in protecting against ischemic brain injury and inhibit apoptosis through inhibiting the cytochrome c/caspase3/HDAC4 pathway.

Topics: Animals; Anti-Inflammatory Agents; Brain Ischemia; Caspase 3; Cytochromes c; Disease Models, Animal; Glucosides; Histone Deacetylases; Male; Monoterpenes; Morris Water Maze Test; Open Field Test; Rats; Rats, Sprague-Dawley; Rotarod Performance Test; Signal Transduction

Parkinson's disease (PD) is second only to Alzheimer's disease as the most common devastating human neurodegenerative disorder. Despite intense investigation, no curative therapy is available for PD. Paeoniflorin, a monoterpene glucoside isolated from the Paeonia lactiflora Pall., possesses wide pharmacological effects in the nervous system. This study aims at evaluating the effect of paeoniflorin on 6-hydroxydopamine (6-OHDA)-induced apoptosis and to characterize involved signal transduction pathways in PC12 cells. Our results showed that paeoniflorin suppresses mitochondria-mediated apoptosis of PC12 cells induced by 6-OHDA, and anti-apoptotic effects of paeoniflorin on PC12 cells might mainly result from its antioxidant capability by increasing glutathione (GSH). Moreover, we also found that paeoniflorin can dramatically attenuate the 6-OHDA-induced nuclear factor κB (NF-κB) translocation without affecting phosphorylation of Akt, JNK, p38, and ERK1/2. 6-OHDA-induced protein kinase Cδ (PKCδ) upregulation was blocked by paeoniflorin treatment in PC12 cells. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor diphenyleneiodonium or NF-κB inhibitor BAY 11-7082 could partially attenuate 6-OHDA-induced cell death. Together, our results indicate that the inhibition of PC12 cell apoptosis by paeoniflorin might be mediated, at least in part, by inhibiting reactive oxygen species (ROS)/PKCδ/NF-κB signaling pathway. This evidence supports the pharmacological potential of paeoniflorin in the management of neurodegenerative disorders associated with oxidative stress, including PD.

Topics: Animals; Antioxidants; Apoptosis; Cell Survival; Cytochromes c; Cytosol; Glucosides; Monoterpenes; NADPH Oxidases; Neuroprotective Agents; NF-kappa B; Oxidative Stress; Oxidopamine; PC12 Cells; Protein Kinase C-delta; Rats; Reactive Oxygen Species; Signal Transduction

Alzheimer's disease (AD) is a major neurodegenerative brain disorder affecting about 14 million people worldwide. Aβ-induced cell injury is a crucial cause of neuronal loss in AD, thus the suppression of which might be useful for the treatment of this disease. In this study, we aimed to evaluate the effect of paeoniflorin (PF), a monoterpene glycoside isolated from aqueous extract of Radix Paeoniae Alba, on Aβ25-35-induced cytotoxicity in SH-SY5Y cells. The results showed PF could attenuate or restore the viability loss, apoptotic increase, and ROS production induced by Aβ25-35 in SH-SY5Y cells. In addition, PF strikingly inhibited Aβ25-35-induced mitochondrial dysfunction, which includes decreased mitochondrial membrane potential, increased Bax/Bcl-2 ratio, cytochrome c release and activity of caspase-3 and caspase-9. Therefore, our study provided the first experimental evidence that PF could modulate ROS production and apoptotic mitochondrial pathway in model of neuron injury in vitro and which might provide new insights into its application toward Alzheimer's disease therapy.

Topics: Amyloid beta-Peptides; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Cell Death; Cell Line, Tumor; Cytochromes c; Enzyme Activation; Glucosides; Humans; Membrane Potential, Mitochondrial; Mitochondria; Monoterpenes; Neuroprotective Agents; Oxidative Stress; Peptide Fragments

The protective effects of paeoniflorin isolated from Paeonia lactiflora against pharmacological inhibition of the respiratory chain were studied using osteoblastic MC3T3-E1 cells. Here we show that paeoniflorin decreases cell death induced by antimycin A, an inhibitor of mitochondrial complex III. Paeoniflorin restored antimycin A-induced inactivation of phosphoinositide 3-kinase (PI3K) and thioredoxin reductase, suggesting that PI3K and thioredoxin reductase may be involved in paeoniflorin-induced cytoprotective responses. We also examined the effect of paeoniflorin on mitochondrial dysfunction and oxidative stress induced by antimycin A. Paeoniflorin inhibited mitochondrial membrane potential dissipation, ATP loss, inactivation of complexes I and IV, cytochrome c release, and cardiolipin oxidation induced by antimycin A. In addition, paeoniflorin prevented antimycin A-induced ROS release and nitrotyrosine increase. These results imply that paeoniflorin protects osteoblasts from antimycin A-induced cell death via improved mitochondrial function.

Topics: 3T3 Cells; Animals; Antimycin A; Antioxidants; Benzoates; Bridged-Ring Compounds; Cardiolipins; Cell Survival; Cytochromes c; Glucosides; Membrane Potential, Mitochondrial; Mice; Mitochondria; Monoterpenes; Osteoblasts; Oxidative Stress; Paeonia; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Plant Extracts; Protective Agents; Reactive Oxygen Species; Thioredoxin-Disulfide Reductase; Tumor Necrosis Factor-alpha; Tyrosine

Paeoniflorin (PF), the principal component of Paeoniae Radix prescribed in traditional Chinese medicine, has been reported to exhibit many pharmacological effects including protection against ischemic injury. However, the mechanisms underlying the protective effects of PF on cerebral ischemia are still under investigation. The present study showed that PF treatment for 14 days could significantly inhibit transient middle cerebral artery occlusion (MCAO)-induced over-activation of astrocytes and microglia, and prevented up-regulations of pro-inflamamtory mediators (TNFα, IL-1β, iNOS, COX(2) and 5-LOX) in plasma and brain. Further study demonstrated that chronic treatment with PF suppressed the activations of JNK and p38 MAPK, but enhanced ERK activation. And PF could reverse ischemia-induced activation of NF-κB signaling pathway. Moreover, our in vitro study revealed that PF treatment protected against TNFα-induced cell apoptosis and neuronal loss. Taken together, the present study demonstrates that PF produces a delayed protection in the ischemia-injured rats via inhibiting MAPKs/NF-κB mediated peripheral and cerebral inflammatory response. Our study reveals that PF might be a potential neuroprotective agent for stroke.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Astrocytes; bcl-2-Associated X Protein; Benzoates; Brain; Brain Ischemia; Bridged-Ring Compounds; Cerebral Infarction; Cyclooxygenase 2; Cytochromes c; Disease Models, Animal; Gene Expression Regulation; Glucosides; Hippocampus; Inflammation; Interleukin-1beta; Lipoxygenase; Male; Microglia; Mitogen-Activated Protein Kinases; Monoterpenes; Neurons; NF-kappa B; Nitric Oxide Synthase Type II; Proto-Oncogene Proteins c-bcl-2; Rats; Signal Transduction; Tumor Necrosis Factor-alpha