AIM:To investigate the anticancer activity of Honokiol on RKO,a human colorectal carcinoma cell line in vitro and in vivo,and to evaluate its possible use in clinic.METHODS:In vitro anticancer activity of honokiol wasdemonstrated by its induction of apoptosis in tumor cells.We analyzed cell proliferation with M-I-r assay,cell cycle withflow cytosmeter,DNA fragment with electrophoresis onagarose gels.To test the mechanism of honokiol-inducedapoptosis,Westem blotting was used to investigate the factorsinvolved in this process.The pharmacokinetics study ofhonokiol was tested by high phase liquid chromatography.In in vivo study,Balb/c nude mice were incubated withRKO cells.Honokiol was injected intraperitoneally everyother day into tumor bearing Balb/c nude mice.RESULTS:Our results showed that honokiol induced apoptosisof RKO cells in a time-and dose-dependent manner.At5-10 ug/mL for 48 h,honokiol induced apoptosis throughactivating Caspase cascades.Pharmacokinetics studydemonstrated that,honokiol could be absorbed quickly byintraperitoneal injection,and maintained in plasma for morethan 10 h.In nude mice bearing RKO-incubated tumor,honokioldisplayed anticancer activity by inhibiting tumor growth andprolonging the lifespan of tumor bearing mice.CONCLUSION:With its few toxicity to normal cells andpotent anticancer activity in vitro and in vivo,honokiol mightbe a potential chemotherapy candidate in treating humancolorectal carcinoma.
