Cytotoxicity of triterpenoids from Clerodendrum glabrum against triple negative breast cancer cells in vitro

Abstract Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β‑hydroxy‑5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines. Interestingly, none of the compounds were toxic towards hormone receptor positive breast cancer cells, while displaying varying toxicity against the TNBC and non-cancerous breast epithelial cells. In particular, lupeol-3-palmitate (47.6 ± 1.50 μM) and glutinol (26.9 ± 1.30 μM) displayed the greatest inhibitory activity against the HCC70 cell line, with the former being selectively toxic to HCC70 and not MCF-12A non-cancerous cells.