title: Effects of Lecythis pisonis Camb. (Lecythidaceae) in a mouse model of pruritus.
abstract: BACKGROUND
  Lecythis pisonis Camb. (Lecythidaceae), is popularly known as "Sapucaia". In traditional medicine, leaves are used for the treatment of pruritus.
  
  
  OBJECTIVE
  The present study is aimed to investigate the antipruritic effect of the ethanol extract from leaves of Lecythis pisonis (LPEE), fractions (hexane-LPHF, ether-LPEF and ethyl acetate-LPEAF) and mixture of triterpenes [ursolic and oleanolic acids (MT)] in mice and rats.
  
  
  METHODS
  The LPEE, LPHF, LPEF, LPEAF and MT were evaluated on scratching behavior induced by compound 48/80 in mice. In addition, LPEE, LPEF and MT were investigated on rat peritoneal mast cells degranulation induced by compound 48/80 (ex vivo study). The anti-inflammatory activity of LPEE and LPEF was investigated in rats using carrageenan-induced hind paw edema model. In the evaluation of the spontaneous motor activity, the LPEE was studied for its effect on spontaneous motor activity in an open-field test in mice.
  
  
  RESULTS
  The scratching behavior induced by compound 48/80 was significantly inhibited in mice pretreated with LPEE, LPHF, LPEF, LPEAF and MT. The suppressive effect of LPEE, LPEF and MT was only partially antagonized by naloxone. In addition, the compound 48/80-elicited degranulation of rat peritoneal mast cells was also markedly reduced in animals pretreated with LPEE, LPEF and MT. In the anti-inflammatory test, LPEE decreased the paw edema at the third hour after carrageenan (Carr) administration. Moreover, LPEF also was able to inhibit the oedematogenic response evoked by carr at all analysed time points. In the open-field test, LPEE-pretreated mice showed no impairment of spontaneous locomotion. Furthermore, the LPEE demonstrated no overt toxicity up to an oral dose of 2g/kg in an acute toxicity assay.
  
  
  CONCLUSIONS
  These results clearly indicate the antipruritic effects of Lecythis pisonis leaves and suggest that this effect may be related to a stabilizing action on mast cell membrane. Furthermore, these data support the traditional use of this plant against cutaneous pruritus.
authors: Medicinal Plants Research Center, Federal University of Piauí, Teresina, Brazil.
authors: L L
authors: LL
authors: Silva
authors: B S
authors: BS
authors: Gomes
authors: B P
authors: BP
authors: Sousa-Neto
authors: J P C
authors: JP
authors: Oliveira
authors: E L F
authors: EL
authors: Ferreira
authors: M H
authors: MH
authors: Chaves
authors: F A
authors: FA
authors: Oliveira
mesh_terms: D000818:Animals; D000982:Antipruritics / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D001522:Behavior, Animal / Q000187:drug effects; D002351:Carrageenan; D015550:Cell Degranulation / Q000187:drug effects; D004195:Disease Models, Animal; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology; D000431:Ethanol / Q000737:chemistry; D004986:Ether / Q000737:chemistry; D005260:Female; D031381:Lecythidaceae / Q000737:chemistry; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000502:physiology; D008519:Medicine, Traditional; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D009828:Oleanolic Acid / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves / Q000737:chemistry; D011537:Pruritus / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents / Q000737:chemistry; D013020:South America; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use; D003189:p-Methoxy-N-methylphenethylamine; D000097245:Ursolic Acid
chemical_list: D000982:Antipruritics; D002351:Carrageenan; D000431:Ethanol; D004986:Ether; D009828:Oleanolic Acid; D010936:Plant Extracts; D012997:Solvents; D014315:Triterpenes; D003189:p-Methoxy-N-methylphenethylamine; D000097245:Ursolic Acid