Metabolite Profiling of Rosemary Cell Lines with Antiproliferative Potential against Human HT-29 Colon Cancer Cells

Rosemary (Rosmarinus officinalis) is a culinary and medicinal plant used in food and pharmaceutical industry. The wide range of biological activities is mainly related to phenolic and terpenic compounds; like carnosic acid (CA), carnosol (CS) and rosmarinic acid (RA), mainly reported in rosemary leaf extracts, and recently described in rosemary callus extracts. The aim of this work was to investigate the chemical profile of rosemary cell lines and evaluate their antiproliferative potential against human HT-29 colorectal cancer cell lines. For this purpose, rosemary leaf explants were dedifferentiated on MS medium and added with 2, 4-D (2, 4-dichlorophenoxyacetic acid; 2 mg/L) and BAP (6-benzylaminopurine; 2 mg/L). Cell aggregates were separated according to colour and three rosemary cell lines cultures were established: green (RoG), yellow (RoY) and white (RoW). The chemical profile of rosemary cell lines extracts was characterized by combining HPLC and GC platforms coupled to HR-MS/MS. The antiproliferative activity against HT-29 cell line was analyzed with MTT assay. A total of 71 compounds, including hydroxycinnamic acid and hydroxybenzoic acid derivatives, flavonoids, phenolic di- and triterpenes, as well as relevant unsaturated fatty acids and their esters, phytosterols, and carotenoids were tentatively identified in the extract of the target cell lines. The antiproliferative activity test against HT-29 cell using the MTT assay revealed that the viability of HT-29 colon cancer cells was affected after treatment with the RoW extract (IC50 of 49.63 μg/mL) at 48 h. These results showed that rosemary cell lines can also accumulate other bioactive phytochemicals with demonstrated antiproliferative potential.