Studies On The Anticancer Activity Of HS-0, A Bioactive Compound From A Chinese Medicinal Herb, CD.

This paper focused on the study of the anticancer activity of HS-0, a bioactive compound from Chinese medicinal herb CD, in vivo & in vitro. Its mechanism of inducing cancer cells apoptosis was also investigated.The tumor growth of mice with S-180 was inhibited compared with the control group after animals were treated with HS-0 p.o. at 12.5, 25, 50 mg/kg/d for 10 days, and the tumor suppression rates of HS-0 at the three doses were respectively 45%, 52% and 58%.In vitro the proliferations of K562, HCT-15 and HT-1080 cells were reduced to 50% by HS-0 when the concentration up to 30 g/ml detected by MTT assay. The IC50 of HS-0 in the three tumor cell lines were 10.436 0.231 g/ml, 7.599 2.004 g/ml, 17.281 2.527 g/ml . HS-0 showed anticancer activity in vivo and in vitro in time- and dose- dependent manner.Moreover, under optic microscope we observed the typical morphological changes of apoptotic cells when incubated with HS-0, which strongly hinted us that HS-0 might exert its anticancer activity through triggering tumor cells apoptosis. So we tested the morphological and biochemical characteristics of tumor cells after treated by HS-0 , including the cell volume analysis by Coulter Multisizer II device, nuclear charter by Hoechst 33258 staining, cell cycle analysis by flow cytometer, mitochondria membrane voltage change by Rhodamine 123 stain, membrane phosphatidyl serine distribution by Annexin V-FITC probe and DNA agarose gel electrophoresis. The results of the above tests strongly supported that the tumor cells experienced apoptosis after treated by HS-0, that is to say , HS-0 could cause tumor cells apoptosis.Then we examined the apoptosis relating proteins expression level by western blotting method. Poly (ADP-ribose) polymersase (PARP) and pRb were cleaved by HS-0 treatment at 20 g/ml for 24 hours, but caspase-3 and caspase-7 were not activated by HS-0, which showed HS-0 and cis- Platinum shared different pathway in initiating apoptosis. The activity of HS-0 on cell cycle inhibition was p53, p21, p27-independent, and HS-0 showed no effect on Bcl-2 and Bax expressions.AbastractSo we came to the conclusion that HS-0 had the anticancer activity through inducing tumor cell apoptosis and its activity was independent of caspase-3,-7, Bcl-2, Bax, p53, p21 and p27.