Atractylon, a novel dopamine 2 receptor agonist, ameliorates Parkinsonian like motor dysfunctions in MPTP-induced mice

Abstract

Background: Motor symptoms of Parkinson's disease (PD) are characterized by bradykinesia, resting tremor, rigidity, slow movement, impaired gait and postural instability, resulting from progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Atractylon is a natural furan compound in Atractylodes rhizomes, exhibiting anticancer, anti-inflammation, antiviral and gastroprotective activities, and so on. However, it is still unknown whether atractylon is beneficial to motor dysfunctions of PD.

Methods: GPCR-targeted piggyBac-TANGO compound screening system, cAMP assay, and immunostaining of p-CREB and BDNF were used to identify dopamine 2 receptor (DRD2) activation. The effects of atractylon on motor deficits and gait disturbances, as well as tyrosine hydroxylase (TH) in the SNpc were investigated in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice.

Results: Atractylon treatment increased the eGFP expression in dose-dependent manner in piggyBac-TANGO assay, decreased cAMP production, and enhanced the levels of p-CREB and BDNF in DRD2 highly expresseding SY-SY5Y cells. In MPTP-induced mice, atractylon improved the slow movement, diminished voluntary locomotion, and abnormal gait parameters, such as duration, cadence, average speed, step cycle, stride length, and so on. Moreover, atractylon rescued the TH positive cells in SNpc and TH positive nerve fibers in striatum.

Conclusions: Atractylon could effectively activate DRD2, attenuate motor deficits and gait disorders, and protect dopaminergic neurons in MPTP-induced PD mice. Our findings stretch out the therapeutic potential of atractylon for motor symptoms of PD.

Keywords: Atractylon; Dopamine 2 receptor; Gait analysis; Motor deficits; Parkinson’s disease.