New pentacyclic triterpene from Potentilla atrosanguinea Lodd. as anticancer agent for breast cancer targeting estrogen receptor-alpha

One new (compound 3) along with two previously known ursane type triterpenoids (compounds 1 and 2) were purified by chromatographic techniques from ethyl acetate extract of aerial parts of Potentilla atrosanguniea and characterized by HRMS, 1 D and 2 D-NMR. Compounds 1 (ursolic acid), 2 (euscaphic acid) and 3 (3 alpha,20 alpha-dihydroxy 2-oxo-urs-12-en-28-oic acid) were tested for their antiproliferative activity along with standard bazedoxifene. Compounds 1 and 3 were found to be of higher activity (3.71 and 6.05 mu g/mL) as compared to compound 2 and bazedoxifene (IC50: 24.53 and 17.87 mu g/mL). Anti-estrogenic activity of three compounds on breast cancer (BC) were studied in vitro by accessing their antiproliferative activity and binding with estrogen receptor alpha (ER-alpha). All three compounds have effective binding affinity towards ER-alpha and decreased cell growth by downregulating the expression of mRNA and its translational protein as tested by semi-qRT-PCR and western blotting. In terms of effectiveness compounds 1 and 3 were found more active due to their antiproliferative, and antiestrogenic activity as compared to standard bazedoxifene.