These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Antiplatelet effects of piplartine, an alkamide isolated from Piper tuberculatum: possible involvement of cyclooxygenase blockade and antioxidant activity.
    Author: Fontenele JB, Leal LK, Silveira ER, Felix FH, Bezerra Felipe CF, Viana GS.
    Journal: J Pharm Pharmacol; 2009 Apr; 61(4):511-5. PubMed ID: 19298699.
    Abstract:
    OBJECTIVES: Piplartine (piperlongumine; 5,6-dihydro-1-[1-oxo-3-(3,4,5-trimethoxyphenyl]-2(1H) pyridinone) is an alkaloid amide isolated from Piper species (Piperaceae). It has been reported to show multiple pharmacological activities in vitro and in vivo. METHODS: We evaluated the in-vitro antiplatelet effect of piplartine isolated from the roots of P. tuberculatum, on human platelet aggregation induced in platelet-rich plasma by the agonists collagen, adenosine 5'-diphosphate (ADP), arachidonic acid (AA) and thrombin. KEY FINDINGS: Piplartine (100 mug/ml) caused a 30% inhibition in platelet aggregation when collagen was the agonist. At 200 mug/ml, piplartine significantly inhibited the aggregation induced by arachidonic acid (100%), collagen (59%) or ADP (52%) but not that induced by thrombin. The highest concentration of piplartine (300 mug/ml) inhibited thrombin- (37%), ADP- (71%) and collagen- (98%) induced aggregation. The inhibitory effect of piplartine on ADP-induced platelet aggregation was not modified by pretreatment with pentoxifylline (a phosphodiesterase inhibitor), L-arginine (a substrate for nitric oxide synthase) or ticlopidine (a P2Y(12) purinoceptor antagonist). However, aspirin, a well-known inhibitor of cyclooxygenase, greatly increased the inhibitory effect of piplartine on arachidonic-acid-induced platelet aggregation. CONCLUSIONS: The mechanism underlying the piplartine antiplatelet action is not totally clarified. It could be related to the inhibition of cyclooxgenase activity and a decrease in thromboxane A(2) formation, similar to that occurring with aspirin. This and other possible mechanisms require further study.
    [Abstract] [Full Text] [Related] [New Search]