Abstract: The objective of this study is to explore and establish the optimal method for cultivating Rabdosia rubescens hairy roots and to test the anti-tumor activity of its extracts. Agrobacterium rhizogenes ATCC11325 and ATCC15834 were used to induce the growth of hairy roots in the R. rubescens explants,the effects of different types of medium and different sucrose concentrations on the growth of R. rubescens hairy roots were investigated,and thereafter,their growth curves were measured. Ultrasound was employed to prepare the crude extract from R. rubescens hairy roots,then the crude extracts were purified via macroporous adsorption resin,and further,the content of oridonin in the extract was determined by high performance liquid chromatography（HPLC）. The purified extracts were formulated into test solutions with different concentrations to be applied on the cancer cell line BEL-7402,A-549,SGC-7901,and HGC,and the cell viability were determined by the CCK-8 method. As results,only ATCC15834 induced adventitious roots from the petiole and the incision on stems,however,no adventitious roots grew in the leaf explants. The genetic identification of adventitious roots was consistent with the characteristics of hairy roots. Hairy roots had the highest proliferation rate in 3% sucrose B5 medium,and the growth curve was similar to a “S” type,the mid-logarithmic phase reached at the 25th day and the plateau phase was at the 70th day. The rude extract from hairy roots by ultrasound and macroporous resin extract were analyzed to have the content of oridonin of 0.0171% and 0.0022%,respectively. When the content of extract from hairy roots was 1 mg/mL,the inhibition rate to 4 cancer cells reached 95% or more. Conclusively,the extract rate from the hairy roots of R. rube is the highest when the hairy roots induced by ATCC15834 to infect the petiole and stem explant of R. rubescens are cultured in 3% sucrose B5 medium with shake flasks for 25 days and then subculturing them for 70 days. The extract from R. rubescens hairy roots contains oridonin that can effectively inhibit the growth of in vitro tumor cells.

Key words: Rabdosia rubescens hairy roots induction, oridonin, optimal method in cultivation, hairy roots extract, anti-tumor activity