title: Further studies on the anticancer activity of citrus limonoids.
abstract: Research in this laboratory has shown that some citrus limonoids can inhibit the development of 7,12-dimethylbenz[a]anthracene-induced oral tumors. The data from these studies have suggested that certain rings in the limonoid nucleus may be critical to antineoplastic activity. Using the hamster cheek pouch model, three new limonoids (ichangensin, deoxylimonin, and obacunone) have now been tested for cancer chemopreventive activity. In the first experiment, it was found that the treatments with ichangensin had no effect on tumor number or burden. In the second experiment, obacunone reduced tumor number and burden by 25 and 40%, respectively, whereas deoxylimonin reduced tumor number and burden by 30 and 50%, respectively. The results with deoxylimonin were significant, p < 0.05. Overall, the data indicated that changes in the A ring of the limonoid nucleus can lead to a loss of anticancer activity, whereas changes in the D ring can be tolerated without any apparent loss of biological activity.
authors.affiliation: Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M University System Health Science Center, 3302 Gaston Avenue, Dallas, Texas 75246, USA. emiller@bcd.tamhsc.edu
authors.forename: Edward G
authors.initials: EG
authors.lastname: Miller
authors.forename: Jo Lynn
authors.initials: JL
authors.lastname: Porter
authors.forename: William H
authors.initials: WH
authors.lastname: Binnie
authors.forename: Ingrid Y
authors.initials: IY
authors.lastname: Guo
authors.forename: Shin
authors.initials: S
authors.lastname: Hasegawa
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001584:Benzoxepins / Q000627:therapeutic use; D002957:Citrus / Q000737:chemistry*; D006224:Cricetinae; D004195:Disease Models, Animal; D005260:Female; D005638:Fruit / Q000737:chemistry*; D036701:Limonins / Q000627:therapeutic use*; D008647:Mesocricetus; D009062:Mouth Neoplasms / Q000139:chemically induced / Q000517:prevention & control; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D001584:Benzoxepins; D036701:Limonins; C489353:deoxylimonin; C489360:ichangensin; C067207:obacunone