title: Antioxidative and antiplatelet effects of aqueous inflorescence Piper betle extract.
abstract: Piper betle, belonging to the Piperaceae family, is a tropical plant, and its leaf and inflorescence are popularly consumed by betel quid (BQ) chewers in Taiwan and many other South and Southeast Asian countries. However, little is known about the biochemical properties of inflorescence Piper betle (IPB) toward reactive oxygen species (ROS) and platelet functions. In the present work, aqueous IPB extract was shown to be a scavenger of H(2)O(2), superoxide radical, and hydroxyl radical with a 50% inhibitory concentration (IC(50)) of about 80, 28, and 73 microg/mL, respectively. IPB extract also prevented the hydroxyl radical induced PUC18 plasmid DNA breaks at concentrations higher than 40 microg/mL. Since ROS are crucial for platelet aggregation, we further found that IPB extract also inhibited the arachidonic acid (AA) induced and collagen-induced platelet aggregation, with an IC(50) of 207 and 335 microg/mL, respectively. IPB extract also inhibited the AA-, collagen- (>100 microg/mL of IPB), and thrombin (>250 microg/mL of IPB)-induced thromboxane B(2) (TXB(2)) production by more than 90%. However, IPB extract showed little effect on thrombin-induced aggregation. These results indicated that aqueous components of IPB are potential ROS scavengers and may prevent the platelet aggregation possibly via scavenging ROS or inhibition of TXB(2) production.
authors.affiliation: Laboratory of Dental Pharmacology & Toxicology, Department of Dentistry, National Taiwan University Hospital and National Taiwan University, College of Medicine, Taipei, Taiwan.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lei
authors.forename: Chiu-Po
authors.initials: CP
authors.lastname: Chan
authors.forename: Ying-Jan
authors.initials: YJ
authors.lastname: Wang
authors.forename: Tong-Mei
authors.initials: TM
authors.lastname: Wang
authors.forename: Bor-Ru
authors.initials: BR
authors.lastname: Lin
authors.forename: Chun-Hsun
authors.initials: CH
authors.lastname: Huang
authors.forename: Jang-Jaer
authors.initials: JJ
authors.lastname: Lee
authors.forename: Hsin-Ming
authors.initials: HM
authors.lastname: Chen
authors.forename: Jiiang-Huei
authors.initials: JH
authors.lastname: Jeng
authors.forename: Mei-Chi
authors.initials: MC
authors.lastname: Chang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001792:Blood Platelets / Q000378:metabolism; D016166:Free Radical Scavengers; D031721:Piper betle / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011817:Rabbits; D013929:Thromboxane B2 / Q000096:biosynthesis
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors; D013929:Thromboxane B2