Screening for Potential Antibreast Cancer Components From Prunellae Spica Using MCF-7 Cell Extraction Coupled with HPLC-ESI-MS/MS

Prunellae Spica (PS), the dry spikes of Prunella vulgaris L., is a medicinal herb widely distributed in Asia and Europe. As a traditional Chinese medicine, PS has been used for the treatment of mastitis, infectious hepatitis, and hypertension. The oral solution and some compounds (polysaccharide, ursolic acid, and betulinic acid) of PS have been reported to show activities against breast cancer. In this study, Michigan Cancer Foundation-7 (MCF-7) cell extraction coupled with high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) analysis was applied to screen for potential antibreast cancer ingredients from PS. Protocatechuic acid (1), protocatechualdehyde (2), caffeic acid (3), and rosmarinic acid (4) were identified as high-affinity components. The cytotoxic activities of these compounds were evaluated in MCF-7 cells using Cell Counting Kit-8 assay. All the compounds displayed cytotoxicity to MCF-7 cells, but protocatechualdehyde and caffeic acid exhibited significant cytotoxicity with half-maximal inhibitory concentration values of 10.9 mu M and 26.8 mu M, respectively. This study provides the first report of the successful usage of cell extraction coupled with LC-MS/MS to screen active ingredients from PS. This method can be used as a screening tool for bioactive constituents in natural products.