Background: Breast cancer is an important problem in human females and therapies used for treatment often found to produce side effects. The present study was conducted to evaluate the effect of Saussurea costus root extract (SC) against metastatic breast cancer to the lungs. 
 
Methods: The anti-neoplastic activity of SC extract was assessed by calculating the % cytotoxicity on Leydig cell testicular tumour cells-540 (LC-540). The anti-metastatic effect of SC extract at 3 different doses (100, 250 and 500 mg/kg BW) for a period of 18 weeks against 12-dimethylbenz (a) anthracene (DMBA) induced mammary tumours in Sprague Dawley (SD) female rats was studied through radiography, gross lesion scoring, histopathology and immunohistochemistry (MMP-9). 
 
Result: SC extract exhibited the highest anti-neoplastic activity in a time and concentration-dependent manner. After 72 h of duration SC extract exhibited highest anti-neoplastic activity at 200 &mu;g of concentration. On radiological and gross pathological examination, the inhibition of metastases was maximal in the rats treated with highest dose of the extract as compared with only DMBA treated group. The histopathological changes and immunohistochemical expression of metastases marker MMP-9 in lung tissue were more severe in the rats treated with DMBA only and were reduced in the groups treated with SC extract in a dose-dependent manner. SC extract has potential anti-neoplastic activity and prevents the rate of metastases from mammary tumours to lungs. Further research in exploring the possible therapeutic usage of SC extract against various neoplastic conditions is warranted.

Prevention of DMBA-induced Mammary Tumors from Pulmonary Metastases by Saussurea costus (Falc.) Lipsc Root Ethanolic Extract in Sprague Dawley Rats