Chemopreventive properties of phytosterols and maslinic acid extracted from Coleus tuberosus in inhibiting the expression of EBV early-antigen in Raji cells.
Bioassay-guided fractionation of a MeOH extract of tubers of Coleus tuberosus afforded the active anti-tumor-promoting compounds identified as the triterpenoid 2alpha,3beta-dihydroxyolean-12-en-28-oic acid (maslinic acid; CT2) and a phytosterol mixture (CT1). CT1 consists of stigmasterol (32%), beta-sitosterol (40.3%), and campesterol (27.7%) as determined by capillary gas chromatography. CT1 and CT2 showed very strong anti-tumor-promoting activities at IC(50) 0.7 microg/ml and 0.1 microg/ml, respectively, in a convenient, short-term in vitro assay, i.e., the inhibition of Epstein-Barr virus (EBV) activation induced by phorbol 12-myristate 13-acetate (PMA) and sodium butyrate. We report for the first time the anti-tumor-promoting activity of 2alpha,3beta-dihydroxyolean-12-en-28-oic acid and show that a mixture of stigmasterol, beta-sitosterol, and campesterol is more potent than the individual components in inhibiting tumor-promoting activity.
Mooi
Lim Yang
LY
Department of Science, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Malaysia. ymlim@utar.edu.my
Wahab
Norhanom Abdul
NA
Lajis
Nordin Haji
NH
Ali
Abdul Manaf
AM
D016588:Anticarcinogenic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D000956:Antigens, Viral / Q000378:metabolism*; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D002087:Butyrates / Q000494:pharmacology; D002460:Cell Line; D031330:Coleus / Q000737:chemistry*; D004854:Herpesvirus 4, Human / Q000187:drug effects; D006801:Humans; D008968:Molecular Conformation; D010840:Phytosterols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D035281:Plant Tubers / Q000737:chemistry; D013755:Tetradecanoylphorbol Acetate / Q000031:analogs & derivatives / Q000494:pharmacology; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D014775:Virus Activation / Q000187:drug effects; D009828:Oleanolic Acid / Q000031:analogs & derivatives
D016588:Anticarcinogenic Agents; D000956:Antigens, Viral; D000972:Antineoplastic Agents, Phytogenic; D002087:Butyrates; D010840:Phytosterols; D013755:Tetradecanoylphorbol Acetate; D014315:Triterpenes; C033305:Epstein-Barr virus early antigen; C020922:4-O-methyl-12-O-tetradecanoylphorbol 13-acetate; C412811:maslinic acid; D009828:Oleanolic Acid