Oridonin, A natural diterpenoid, protected NGF-differentiated PC12 cells against MPP+- and kainic acid-induced injury
Graphical abstract
Introduction
Oridonin (ORI) is a diterpenoid presented in Rabdosia rubescens and Rabdosia excisa, and these two herbs are commonly used in traditional Chinese medicine to treat inflammatory disorders (Wu et al., 2012). It has been documented that ORI exhibited in vitro and in vivo inhibitory effects against lung cancer, liver cancer and breast cancer through limiting nuclear factor (NF) κB transcription, angiogenesis and epithelial-mesenchymal transition (Wang et al., 2014; Li et al., 2018). So far, the neuro-protective effects of ORI have attracted attention. Zhang et al. (2013) reported that ORI could alleviate inflammatory reactions in microglial cells, decrease β-amyloid deposition and suppress microglial activation in brain of transgenic mice. The study of Wang et al. (2016) revealed that ORI rescued Aβ1-42 induced synaptic loss and improved mitochondrial activity in synaptosomes of mice with Alzheimer's disease. Those previous literatures suggest that ORI is able to protect brain and neuronal system. However, less attention was paid to the potent of ORI to attenuate Parkinson's disease (PD) and/or seizure.
PD is a neurodegenerative disease due to the loss of nigrostriatal dopamine (DA) neurons and the accumulation of α-synuclein in astrocytes, which further cause neurotransmitters deficiency and even neurotoxicity at striatum (Devi et al., 2008; Chen et al., 2015). Both inflammatory and oxidative responses are involved in pathological development of PD (Hald and Lotharius, 2005; Yadav et al., 2014). High levels of inflammatory cytokines such as interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha have been found in nigrostriatal DA regions and lumbar cerebrospinal fluid of PD patients (Nagatsu et al., 2000). In addition, tyrosine hydroxylase (TH) is the rate-limiting enzyme for the conversion of tyrosine to DA and other catecholamines. The reduced TH activity or expression resulted in DA loss and favored the progression of PD (Bademci et al., 2012). 1-Methyl-4-phenylpyridinium (MPP+) is the metabolite of an environmental toxin, 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine. MPP+ limits mitochondrial complex I, leads to ATP depletion, induces oxidative injury and cell death (Smeyne and Jackson-Lewis, 2005). Thus, MPP+ has been widely used as a neurotoxin to induce PD symptoms in cells or rodents’ models (Liu et al., 2015).
Seizure is a neurological disorder due to the over-reactivity of nerve cells in brain, especially in the area of hippocampus. Both inflammatory and oxidative stresses also play crucial roles in the etiopathogenesis of seizure (Vezzani et al., 2011; Huang et al., 2012). The massive release of inflammatory cytokines and reactive oxygen species (ROS) impairs nerve cell integrity, and initiates nerve cell apoptosis (Han et al., 2012). In addition, glutamate excitotoxicity due to the increased extracellular glutamate level in brain hyper-excitable areas promotes neuronal excitability and enhances seizure induction (Takanashi et al., 2015). Glutamine synthetase (GS) is in charge of glutamate clearance through converting glutamate to glutamine (Eid et al., 2013). It is reported that kainic acid (KA) could disturb nerve impulse transmission, depolarize neuronal membranes, cause focal hippocampal lesion and evoke seizure-like neuronal excitability (Malva et al., 2003). Thus, KA treated neuronal cells or rodents have been often used as seizure research models (Han et al., 2012; Huang et al., 2012).
In our present cell line study, the effects of pre-treatments from ORI at different concentrations against MPP+- or KA- induced damage in nerve growth factor (NGF)-differentiated PC12 cells were investigated. The effects of ORI upon cell survival, plasma membrane integrity, DA and glutamine levels, and mRNA expression of TH and GS were examined. In addition, the influence of ORI upon the change in Na+-K+ ATPase activity, an indicator of mitochondrial malfunction and even motor neuron death (Ellis et al., 2003), was evaluated. These results could enhance our understanding regarding the possibility of using ORI as an anti-PD or anti-seizure agent.
Section snippets
Materials
ORI (98%) was purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). MPP+, KA (99.5%) and NGF (99%) were purchased from Wako Chemical Co. (Tokyo, Japan). Antibiotics, medium and plates used for cell culture were obtained from Difco Laboratory (Detroit, MI, USA).
Cell culture and treatments
PC12 cells were regularly cultured with Dulbecco's modified Eagle's medium (DMEM) under 95% air and 5% CO2 at 37 °C. PC12 cells were first treated with NGF at 50 ng/ml, and followed by a 5-day incubation at 37 °C for cell
ORI at high concentrations impaired cell survival
The effects of ORI treatments alone upon cell viability and plasma membrane damage determined by LDH activity are presented in Fig. 1. After 48 h treatment, ORI at 0.25–4 μM did not affect the viability and plasma membrane stability of NGF-differentiated PC12 cells (P > 0.05). However, ORI treatments for 48 h at 8–32 μM dose-dependently decreased cell viability and increased LDH activity (P < 0.05).
ORI enhanced cell survival
As shown in Fig. 2, pre-treatments of ORI for 48 h at 0.25–2 μM protected NGF-differentiated
Discussion
The protective effects of ORI, a diterpenoid, for brain and neuronal system against β-amyloid deposition, microglial inflammation and synaptic dysfunction have been reported (Zhang et al., 2013; Wang et al., 2016). Our present study extended the neuronal protective possibilities of ORI toward PD and seizure. We found that ORI pre-treatments at 0.25–2 μM markedly decreased caspase-3 activity, stabilized Na+-K+ ATPase activity, attenuated oxidative and inflammatory stress, and enhanced cell
Conflicts of interest
All authors stated that no Conflict of Interest.
Acknowledgement
This study was partially supported by a grant from Asia University (ASIA-106-CMUH-29).
References (36)
- et al.
Irisflorentin improves α-synuclein accumulation and attenuates 6-OHDA-induced dopaminergic neuron degeneration, implication for Parkinson's disease therapy
Biomedicine
(2015) - et al.
Mitochondrial import and accumulation of alpha-synuclein impair complex I in human dopaminergic neuronal cultures and Parkinson disease brain
J. Biol. Chem.
(2008) - et al.
Extracellular hippocampal glutamate and spontaneous seizure in the conscious human brain
Lancet (London, England)
(1993) - et al.
Regulation of astrocyte glutamine synthetase in epilepsy
Neurochem. Int.
(2013) - et al.
Oxidative stress and inflammation in Parkinson's disease: is there a causal link?
Exp. Neurol.
(2005) - et al.
Neuroprotective effect of osthole on MPP+-induced cytotoxicity in PC12 cells via inhibition of mitochondrial dysfunction and ROS production
Neurochem. Int.
(2010) - et al.
The MPTP model of Parkinson's disease
Brain Res. Mol. Brain Res.
(2005) - et al.
Chemical constituents of flowers and fruits of Rabdosia excisa
Chin. J. Nat. Med.
(2012) - et al.
Tyrosine hydroxylase gene: another piece of the genetic puzzle of Parkinson's disease
CNS Neurol. Disord. - Drug Targets
(2012) - et al.
Global loss of Na, K-ATPase and its nitric oxide-mediated regulation in a transgenic mouse model of amyotrophic lateral sclerosis
J. Neurosci.
(2003)
Current status of tyrosine hydroxylase in management of Parkinson's disease
CNS Neurol. Disord. - Drug Targets
Protection of apigenin against kainate-induced excitotoxicity by anti-oxidative effects
Biol. Pharm. Bull.
Bioassay-guided isolation of neuroprotective fatty acids from Nigella sativa against 1-methyl-4-phenylpyridinium-induced neurotoxicity
Pharmacogn. Mag.
Pu-Erh tea and GABA attenuates oxidative stress in kainic acid-induced status epilepticus
J. Biomed. Sci.
Fresh green tea and gallic acid ameliorate oxidative stress in kainic acid-induced status epilepticus
J. Agric. Food Chem.
Faster flux of neurotransmitter glutamate during seizure - evidence from 13C-enrichment of extracellular glutamate in kainate rat model
PLoS One
Targeting Parkinson's - tyrosine hydroxylase and oxidative stress as points of interventions
CNS Neurol. Disord. - Drug Targets
Catecholamines: role in health and disease
Drugs
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These two authors equally contributed to this study.