Introduction:
Hydroxysafflor yellow A is the major active chemical ingredient of Carthamus tinctorius L. (safflower), which is widely used in patients with cardiovascular and cerebrovascular diseases in China.

Material and methods:
In our study, the inhibitory effect of hydroxysafflor yellow A on collagenase showed a lower value, IC50 = 78.81 µg/ml. In the cellular and molecular part of the recent study, the cells treated with hydroxysafflor yellow A were assessed by MTT assay for 48 h as regards the cytotoxicity and anti-small cell lung cancer effects on SBC-3, DMS273, and DMS114 cell lines.

Results:
The viability of small cell lung cancer cell lines decreased dose-dependently in the presence of hydroxysafflor yellow A. The IC50 values of hydroxysafflor yellow A were 539, 432, and 416 µg/ml against SBC-3, DMS273, and DMS114 cell lines, respectively. A molecular docking study was carried out for evaluation of the biological activity of hydroxysafflor yellow A against the collagenase H from Clostridium histolyticum.

Conclusions:
The results of the docking calculations revealed the considerable binding affinity of the inhibitor to the enzyme with a docking score of –9.238 (kcal/mol). This remarkable binding affinity could be attributed to the number of hydrogen bonds and hydrophobic contacts, which are 6 and 10, respectively.