title: Neuroprotective effects of alkaloids from Piper longum in a MPTP-induced mouse model of Parkinson's disease.
abstract: BACKGROUND
  Alkaloids of Piper longum L. (Piperaceae) (PLA) include piperine and piperlonguminine. Piper longum and piperine have multiple biological properties including antioxidant activity.
  
  
  OBJECTIVE
  The present study investigated the neuroprotective effects of PLA in a MPTP-induced mouse model of Parkinson's disease.
  
  
  METHODS
  PLA was prepared by extracting the dry seed of P. longum using 85% ethanol. Adult male C57BL/6 mice were divided into eight groups of 12 rats each. Experimental and control groups received an equivalent volume of saline, 0.5% CMC-Na, and 0.1% Tween 80, treated groups received oral PLA (30, 60, and 120 mg/kg), other groups treated with piperine (60 mg/kg) or Madopar (50 mg/kg). The PLA prevention group (PLA-Pr) administrated PLA (120 mg/kg) for 1 week before MPTP challenged. Except for the PLA-Pr group, others were treated for seven consecutive weeks. Parkinson's disease was induced by injecting MPTP intraperitoneally (25 mg/kg) twice weekly for five consecutive weeks. Dopaminerigic (DA) neurons and their metabolism were detected by UFLC-MS/MS. Tyrosine hydroxylase (TH)-immunohistochemistry assay and Western blotting were performed. The antioxidant enzymatic levels were determined by kit-based assays.
  
  
  RESULTS
  The LD50 value of PLA was determined at 1509 mg/kg of body weight. PLA (60 mg/kg) can significantly increase total movement time and distance (p < 0.05), increase levels of DA (p < 0.05) and DOPAC (p <  .05), increase glutathione (GSH) level and superoxide dismutase (SOD) activity (p < 0.05), and decrease the lipid peroxidation of malondiadehycle (MDA) (p < 0.05) in PLA-treated groups as compared with the control group.
  
  
  CONCLUSIONS
  Our results indicate that PLA possesses neuroprotective effects and has ameliorative properties in dopaminergic neurons.
authors: Beijing Key Lab of TCM Collateral Disease Theory Research, School of Traditional Chinese Medicine, Capital Medical University , Beijing , PR China .
authors: Ying
authors: Y
authors: Bi
authors: Peng-Cheng
authors: PC
authors: Qu
authors: Qing-Song
authors: QS
authors: Wang
authors: Li
authors: L
authors: Zheng
authors: Hao-Long
authors: HL
authors: Liu
authors: Rong
authors: R
authors: Luo
authors: Xiao-Qing
authors: XQ
authors: Chen
authors: Yin-Ying
authors: YY
authors: Ba
authors: Xia
authors: X
authors: Wu
authors: Hui
authors: H
authors: Yang
mesh_terms: D000470:Alkaloids / Q000302:isolation & purification / Q000627:therapeutic use*; D000818:Animals; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018696:Neuroprotective Agents / Q000302:isolation & purification / Q000627:therapeutic use*; D020734:Parkinsonian Disorders / Q000378:metabolism / Q000517:prevention & control*; D031701:Piper; D016896:Treatment Outcome
chemical_list: D000470:Alkaloids; D004365:Drugs, Chinese Herbal; D018696:Neuroprotective Agents
keywords: Antioxidants; Piperaceae; lipid peroxidation; oxidative stress