ABSTRACT
Parkinson′s disease(PD),the second neurodegenerative disease in the world,is characterized by a combination of motor symptoms(rest tremor,bradykinesia,rigidity,postural instability,stooped posture and freezing of gait)and non-motor symp?toms(including psychiatric and cognitive disorders). The core neuropathological features of PD are the loss of dopaminergic neurons in the substantia nigra and the deposition of iron and cytoplasmic protein aggregates(Lewy bodies)inside neurons. Currently,clinical treatment for PD is symptomatic and there is no effective treatment to restore neuronal degeneration. In the PD therapy ,medication re?mains dominant. Anti-PD drugs are mainly based on the critical signal pathways or some specific targets which play a key role in the pathogenesis of PD to relieve the symptoms of PD. Research and development in novel drugs to prevent or treat PD have been a crucial subject,and some novel candidates are under development. In this paper,we summarize and analyze the anti-PD drugs,and make a brief discussion about its pharmacological targets.
ABSTRACT
Objective To develop and validate a simple,rapid,sensitive,and reproducible HPLC method for simultaneous determination of baicalein and its metabolite baicalin in dog plasma and for the subsequent pharmacokinetic study after iv administration to dogs.Methods An accurate and reproducible HPLC-UV method was developed and validated for simultaneous determination of baicalein and baicalin in dog plasma,using luteolin as internal standard.The analytes were separated by an Agilent Zorbax SB-C column(250 mm×4.6 mm,5μm)and the column temperature was maintained at 40 ℃.The mobile phase was a binary mixture of acetonitrile and water(27:73),containing 0.05% phosphoric acid in water,with a flow rate of 1.0 mL/min.The UV detector was set al 276 nm.Results Linear relationships were validated over the range of 0.05-25 μg/mL for baicalein and 0.05-20 μg/mL for baicalin.The intra-and inter-day precision values for all samples were within 8.0%,using relative standard deviation.This method was successfully applied to the pharmacokinetic studies in dogs after iv administration of baicalein.Baicalein was converted to baicalin quickly.Cmax values were 21.13 μg/mL at 0.05 h for baicalein and 1.57 μg/mL at 0.5 h for baicalin,areas under the plasma concentration-time curve were 4.97 h.μg/mL for baicalein and 0.63 h.μtg/mL for baicalin,and the elimination half-life is 0.50 h for baicalein and 0.75 h for baicalin,respectively.Conclusion The method is able and sufficient to be used in drug metabolism and pharmacoklnetic studies of baicalein.