title: Antithrombotic and antiallergic activities of rhaponticin from Rhei Rhizoma are activated by human intestinal bacteria.
abstract: To evaluate the antithrombotic and antiallergic properties of rhaponticin extracted from Rhei Rhizoma, the in vitro and ex vivo inhibitory activities of rhaponticin and its metabolite, rhapontigenin, were measured. These compounds inhibited in vitro ADP- and collagen-induced platelet aggregation. Rhapontigenin was more potent, with IC50 values of 4 and 70 microg/ml, respectively. In ex vivo ADP- and collagen-induced rat platelet aggregation, these compounds also exhibited a potent inhibitory effect. The antiplatelet aggregation effects of rhaponticin and rhapontigenin were more potent than those of aspirin. Rhapontigenin showed significant protection from death due to pulmonary thrombosis in mice. Rhapontigenin also showed the strongest inhibitory activity against beta-hexosaminidase release induced by DNP-BSA. These compounds inhibited PCA reaction in mice. Rhapontigenin intraperitoneally administered showed the strongest inhibitory activity and significantly inhibited PCA at doses of 25 and 50 mg/kg, with inhibitory activities of 48 and 85%, respectively. The inhibitory activity of orally administered rhaponticin was stronger than that of intraperitoneally administered rhaponticin. These results suggest that rhaponticin, in the rhizome of Rhei Rhizoma, is a prodrug that has extensive antiallergic and antithrombotic properties.
authors.affiliation: College of Pharmacy, Kyung Hee University, Dongdaemun-ku, Seoul, Korea.
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Park
authors.forename: Min-Kyung
authors.initials: MK
authors.lastname: Choo
authors.forename: Hae-Kyung
authors.initials: HK
authors.lastname: Yoon
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kim
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000378:metabolism / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D001419:Bacteria / Q000378:metabolism*; D001711:Biotransformation; D001777:Blood Coagulation / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005343:Fibrinolytic Agents / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D006821:Hyaluronoglucosaminidase / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D007422:Intestines / Q000382:microbiology*; D008297:Male; D051379:Mice; D010323:Passive Cutaneous Anaphylaxis / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012250:Rheum / Q000737:chemistry*; D013267:Stilbenes / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
chemical_list: D018926:Anti-Allergic Agents; D000975:Antioxidants; D004791:Enzyme Inhibitors; D005343:Fibrinolytic Agents; D013267:Stilbenes; D006821:Hyaluronoglucosaminidase; D001619:beta-N-Acetylhexosaminidases; C023538:rhapontin