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[Growth inhibition of tanshinones on SPC-A-1 cell line and their structure-activity relationship].

BACKGROUND AND OBJECTIVE
Numerous studies have shown that Tanshinones have anti-tumor effects in vitro, but few studies were focusing on the anti-tumor activity of Tanshinones against one special cancer cell line. The aim of this study is to investigate the growth inhibition effect of four Tanshinones on SPC-A-1 cell line and the relationship between their structures and cytotoxicity.


METHODS
The modified MTT assay was adopted to measure the inhibition effect of Tanshinones on SPC-A-1 cells at different concentrations at 24 h, 48 h and 72 h, and the changes of cell morphology were observed by inverted phase contrast microscope.


RESULTS
Tanshinones could inhibit the proliferation of SPC-A-1 cells effectively, and their cytotoxicities on SPC-A-1 cells are all in concentration-dependent and time-dependent manners. The IC50 of dihydro-Tanshinone I, Tanshinone I, Tanshinone IIA and Cryptotanshinone at 24 h were 2.77 μg/mL, 6.01 μg/mL, over 10 μg/mL and over 10 μg/mL, at 48 h were 1.80 μg/mL, 4.04 μg/mL, 8.12 μg/mL, 8.71 μg/mL, at 72 h were 1.36 μg/mL, 1.69 μg/mL, 3.81 μg/mL, 7.35 μg/mL, respectively.


CONCLUSIONS
All of the four Tanshinones have proliferation inhibitory effects on SPC-A-1 cell line, among which the Dihydrotanshinone I is the most active one, followed by Tanshinone I, Tanshinone IIA and Cryptotanshinone subsequently. The results showed that the structure of aromatic ring A could enhance the cytotoxicity and the structure of furan ring C would influence the cytotoxicity, but the mechanism is still remained to be further investigated.