Research paperIdentification and optimization of piperine analogues as neuroprotective agents for the treatment of Parkinson’s disease via the activation of Nrf2/keap1 pathway
Graphical abstract
Introduction
Parkinson’s disease (PD) is one of the most common incurable neurodegenerative diseases, which affects about 1% of global elderly over sixty ages and more than 3% over eighty ages, that brings severe financial and society burden [1]. It has been characterized by cardinal motor symptoms, such as resting tremor, muscular rigidity, akinesia, and postural instability resulting from the loss of dopamine (DA) neurons in the substantia nigra (SN) and the depletion of the neurotransmitter DA in the striatum [2]. Currently, dopamine precursor levodopa [3] (dopaminergic agents) as well as adamantamine hydrochloride and cabergoline (direct or indirect dopamine agonist) are the most widely used drugs for PD treatment. Among the agents, levodopa remains the cornerstone for managing PD patients, especially in the early stages [4]. Other drugs are generally used in combination with levodopa to control specific symptoms or to enhance levodopa activity [3]. However, those drugs only ameliorate motor symptoms for a short period of time and even cause side effects, such as l-DOPA-induced dyskinesia, when taken for long periods [5,6]. So far, no drugs have been developed to slow or reverse the neurodegenerative process in PD [7]. Therefore, it is important to develop new therapies preventing the death of DA neurons in PD-affected brain areas.
Recently, the role of oxidative stress in neurological abnormalities, including PD, has been particularly addressed. Oxidative stress is a disturb of the balance of cellular antioxidant defense systems by over expression of reactive oxygen species (ROS) [8]. Nuclear factor erythroid 2-related factor 2 (Nrf2) is the master regulator of cellular defense against oxidative stress [9]. Under normal conditions, Nrf2 is rapidly degraded (half-life ∼ 20min) by the Kelch like ECH-associated protein 1 (Keap1), an adaptor in the Cul3 (cullin3)-based ubiquitin E3 ligase, mediated ubiquitin proteasome system. Under stress conditions, oxidants and electrophiles react with cysteine sensors within Keap1, causing a conformational change of Keap1 and a detachment of Nrf2 from Keap1, which allows Nrf2 to translocate to the nucleus where Nrf2 binds to antioxidant responsive elements (ARE) via hetero-dimerization with small Maf proteins, activating the expression of its target genes, including several antioxidant and detoxification genes, such as heme oxygenase-1 (HO-1), superoxide dismutase (SOD), NAD(P)H: quinoneoxidoreductase (NQO1), the glutamate-cysteine ligasemodifer (GCLM) and the catalytic (GCLC) subunit [10,11]. Therefore, activating the Keap1/Nrf2 signaling pathway has been considered to be able to reduce and prevent neuronal cell death, representing a promising avenue for PD therapy [12,13].
Covalently modifying the thiol-rich Keap1 protein via electrophilic molecules is the major strategy for Nrf2 activation, which sparked the interest of the pharmaceutical industry and led to a substantial improvement in the clinical development of NRF2 modulators [9]. The first Nrf2-inducer dimethyl fumarate (Tecfidera) with the mechanism of reacting with Cys151 of Keap 1 protein has been approved by FDA for the treatment of remitting-relapsing multiple sclerosis and psoriasis [14,15]. CDDO, the first phase II clinical drug for the treatment of diabetic nephropathy, and its methyl ester (bardoxolone methyl or CDDO-Me), phase III for the treatment of chronic kidney disease and hypertension, pulmonary arterial are also thought to react with Cys151 for the activation of Nrf2 through its α,β-unsaturated scaffold [16]. Some other Nrf2 activators based on different scaffolds are under clinical development at various stages, such as cyanoenone triterpenoids, fumaric acid analogues, curcumin, and isothiocyanate sulforaphane (SFN) [16]. Thus, chemicals with electrophilic scaffold, especially α,β-unsaturated ketone structure, have the potentials for the treatment of PD through Nrf2 activation. Piperine (PIP) as a major alkaloid, isolated from the fruits of Piper longum and Piper nigrum [17], demonstrated various of biological activities [[18], [19], [20], [21], [22], [23], [24]]. Its α,β-unsaturated ketone structure makes a perfect lead for the Nrf2 activator development. Previously, PIP has been reported to exhibit good neuroprotective effects in both 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP) or 6-OHDA induced Parkinson’s animal models through antioxidant, anti-apoptotic and anti-inflammatory mechanism [25,26]. In order to improve the neuroprotective activity of PIP, we synthesized a series of PIP analogues following the strategy shown in Chart 2 and evaluated their neuroprotective activities in H2O2 induced PC12 cell damage model. Among the forty-one PIP derivatives, 3b exhibited the best neuroprotective effect. The cellular assay showed that 3b demonstrated cytoprotection effects via suppression of ROS accumulation and restoration of mitochondrial membrane potential in PC12 cells, which might be related to the activation of Nrf2 and the expression of corresponding antioxidant protein by promoting Nrf2 entry into the nucleus, thereby activating cellular oxidative stress and protecting PC12 cells. Moreover, the neuroprotective effect of 3b was abolished when Nrf2 was knockdown by shRNA transfection, which further confirmed that Nrf2 was crucial for the neuroprotective effect of 3b. Molecular docking study with the homology structure for the all length Keap1 constructed by I-TASSER online service also showed that 3b might activate Nrf2 through covalently binding with Cys residues in Keap1 based on the lowest binding energy. In in vivo experiment, 3b improved motor behavior and rescued dopaminergic neuronal cell death against MPTP induced PD mice model.
Section snippets
Protection of PC12 cells against H2O2-induced cell damage by PIP analogues
Hydrogen peroxide (H2O2), an endogenous cellular signaling molecule could generate exogenous free radicals immediately [27]. Neuronal damage in the nervous system induced by abnormal high levels of H2O2 has been implicated in AD, PD and other neurodegenerative diseases [27]. Since H2O2 at concentration of 650 μM could induced approximate 50% PC12 cell damage (Fig. S1), it was then chosen for the further study. Neuroprotective effects of PIP analogues (12.5 μM) against H2O2-induced damage of
Conclusion
PIP as a natural alkaloid, isolated from the fruits of Piper longum and Piper nigrum [17], has been reported that it has the ability to activate Nrf2 [[41a][41b], [41a]]ssss and has in vivo activity in MPTP or 6-OHDA induced PD mouse model [25,26]. However, the clinical usage was obstructed partially due to the low activity and undisclosed exacted mechanism [ref]. In order to improve the activity of PIP, a series of piperine analogues were designed and synthesized and their neuroprotective
Chemistry
All commercially available reagents were used without further purification. All solvents were dried and redistilled prior to use in the usual manner. Reaction progress was monitored using analytical thin layer chromatography (TLC) on precoated silica gel GF254 (Yantai, China) plates and the spots were detected under UV light (254 nm and 360 nm). Column chromatography was performed on silica gel (200–300 mesh, Yantai, China). 1H and 13C NMR spectra were on a Bruker Avance 400 spectrometer
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgement
The authors appreciate the financial support from the National Natural Science Foundation of China (81527806 and 81874297) and the 1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University (ZY2017202).
References (53)
- et al.
Emerging roles of Nrf2 and phase II antioxidant enzymes in neuroprotection
Prog. Neurobiol.
(2013) - et al.
Antioxidant and anti-inflammatory effects of curcuminoid-piperine combination in subjects with metabolic syndrome: a randomized controlled trial and an updated meta-analysis
Clin. Nutr.
(2015) - et al.
Piperine ameliorated lupus nephritis by targeting AMPK-mediated activation of NLRP3 inflammasome
Int. Immunopharmacol.
(2018) - et al.
Antidepressant like effects of piperine in chronic mild stress treated mice and its possible mechanisms
Life Sci.
(2007) - et al.
Rosmarinic acid attenuates β-amyloid-induced oxidative stress via Akt/GSK-3β/Fyn-mediated Nrf2 activation in PC12 cells
Free Radic. Biol. Med.
(2018) - et al.
Withaferin a induces heme oxygenase (HO-1) expression in endothelial cells via activation of the Keap1/Nrf2 pathway
Biochem. Pharmacol.
(2016) - et al.
Design, synthesis and biological evaluation of chalcone analogues with novel dual antioxidant mechanisms as potential anti-ischemic stroke agents
Acta Pharm. Sin. B
(2019) - et al.
Piperine protects cisplatin-induced apoptosis via heme oxygenase-1 induction in auditory cells
J. Nutr. Biochem.
(2007)et al.Synthesis of coumaperine derivatives: their NF-κB inhibitory effect, inhibition of cell migration and their cytotoxic activity
Eur. J. Med. Chem.
(2016) - et al.
Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells
Sci. Rep.
(2015) - et al.
Different electrostatic potentials define ETGE and DLG motifs as hinge and latch in oxidative stress response
Mol. Cell Biol.
(2007)
Crystal-contact engineering to obtain a crystal form of the Kelch domain of human Keap1 suitable for ligand-soaking experiments
Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun.
VERIFY3D: assessment of protein models with three-dimensional profiles
Methods Enzymol.
Autodock4 and autodocktools4: automated docking with selective receptor flexibility
J. Comput. Chem.
Optimization of vinyl sulfone derivatives as potent nuclear factor erythroid 2-related factor 2 (Nrf2) activators for Parkinson’s Disease therapy
J. Med. Chem.
Converging pathways in neurodegeneration, from genetics to mechanisms
Nat. Neurosci.
Pathogenesis of Parkinson’s disease, Movement disorders
Off. J. Mov. Disord. Soc.
A phase Ib randomized controlled study to evaluate the effectiveness of a single-dose of the NR2B selective N-methyl-D-aspartate antagonist MK-0657 on levodopa-induced dyskinesias and motor symptoms in patients with Parkinson disease
Clin. Neuropharmacol.
Levodopa in the treatment of Parkinson’s disease: an old drug still going strong
Clin. Interv. Aging
An update on the diagnosis and treatment of Parkinson disease
Can. Med. Assoc. J.
ADS-5102 (amantadine) extended release capsules for levodopa-induced dyskinesia in Parkinson disease (EASE LID study): a randomized clinical trial
JAMA Neurol.
The impact of mathematical modeling in understanding the mechanisms underlying neurodegeneration: evolving dimensions and future directions
CPT Pharmacometrics Syst. Pharmacol.
The role of oxidative stress in neurodegenerative diseases
Exp. Neurobiol.
Discovery and development of kelch-like ECH-associated protein 1. nuclear factor erythroid 2-related factor 2 (KEAP1:NRF2) protein-protein interaction inhibitors: achievements, challenges, and future directions
J. Med. Chem.
Global mapping of binding sites for Nrf2 identifies novel targets in cell survival response through ChIP-Seq profiling and network analysis
Nucleic Acids Res.
Cell survival responses to environmental stresses via the Keap1-Nrf2-ARE pathway
Annu. Rev. Pharmacol. Toxicol.
Synthesis of piperlongumine analogues and discovery of nuclear factor erythroid 2-related factor 2 (Nrf2) activators as potential neuroprotective agents
J. Med. Chem.
Cited by (34)
Recent progress and applications of small molecule inhibitors of Keap1–Nrf2 axis for neurodegenerative diseases
2024, European Journal of Medicinal ChemistryThe role of Nrf2/HO-1 signal pathway in regulating aluminum-induced apoptosis of PC12 cells
2023, Journal of Trace Elements in Medicine and BiologyDesign, synthesis, and SAR study of novel flavone 1,2,4-oxadiazole derivatives with anti-inflammatory activities for the treatment of Parkinson's disease
2023, European Journal of Medicinal ChemistryPiperine ameliorates psoriatic skin inflammation by inhibiting the phosphorylation of STAT3
2023, International ImmunopharmacologyPotential roles of gut microbiota and microbial metabolites in Parkinson's disease
2021, Ageing Research ReviewsCitation Excerpt :Notably, several other disorders such as essential tremor (ET; Rajput et al., 2019), multiple system atrophy (MSA; Yu et al., 2020) and progressive supranuclear palsy (PSP; Ali et al., 2019; Piot et al., 2020) are accompanied by similar motor signs and symptoms, thus presenting practical challenges to the diagnosis of PD. At present, the main therapeutic strategies for treating PD involve pharmacological approaches—including through the use of dopamine precursor levodopa, catechol-o-methyl transferase (COMT) inhibitors (Balestrino and Schapira, 2020), monoamine oxidase B (MAO-B) inhibitors (Tábi et al., 2020), anticholinergics (Rajan et al., 2020) and dopamine agonists (Wang et al., 2020)—as well as nonpharmacologic approaches such as deep brain stimulation (Deuschl and Krack, 2020; Hacker et al., 2020). Administration of dopamine modulators is the first-line intervention in PD management, even though this treatment does not slow the neurodegenerative process of PD and can exert serious side effects (Wang et al., 2020).
Development and optimization of halogenated vinyl sulfones as Nrf2 activators for the treatment of Parkinson's disease
2021, European Journal of Medicinal Chemistry
- 1
These authors contributed equally.