Phenolic compounds in rosemary as potential source of bioactive compounds against colorectal cancer: In situ absorption and metabolism study

Phenolic compounds in rosemary have shown antiproliferative/cytotoxic activity against colorectal cancer cells. The aim of this work was to study in depth the absorption and metabolism of the compounds present in a rosemary extract. An in-situ perfusion assay was performed in mice, for which samples of gastrointestinal liquid taken at different times and plasma obtained at the end of the experiment were analysed by HPLC-ESI-QTOF-MS. The absorption-rate coefficients showed that flavonoids and diterpenes were highly absorbed compared to triterpenes. Several diterpenes and their metabolites were also bioavailable in plasma, highlighting the higher concentrations of glucuronide metabolites compared to non-metabolised phenolic compounds. The antiproliferative/cytotoxic properties could be attributed to the absorbed diterpenes and metabolites, which could reach the colon through bloodstream. On the other hand, compounds poorly absorbed, such as triterpenes and some diterpenes, could exhibit their bioactivity in the large intestine by a mechanism of direct interaction with the microbiota.