Thymus carnosus extracts induce anti-proliferative activity in Caco-2 cells through mechanisms that involve cell cycle arrest and apoptosis

Abstract

Thymus carnosus is a thyme species rich in bioactive compounds with potential medicinal properties, but the effect of its extract are poorly studied. This work aims to compare the effect of aqueous (decoction) and hydroethanolic (HE) extracts from T. carnosus aerial parts, concerning anti-proliferative activity and underlying mechanisms.Caco-2 and HepG2 cells exposure to extracts induced dose- and time-dependent reduction in cell viability. Decoction showed very low toxicity (IC50 > 500 µg/mL (both cell lines) comparing to HE (IC50 ∼ 30 (Caco-2) and ∼120 (HepG2) µg/mL). Dose-dependent cell cycle arrest was observed in Caco-2 cells exposed to both extracts. At IC50 concentrations, HE extracts only slightly increase Annexin/PI double staining, while decoction extracts significantly increased Annexin/PI fluorescence which results in a dose-dependent large increase of cells in late apoptosis.In conclusion, Thymus carnosus anti-proliferative activity against Caco-2 cells highlights the potential of this plant, and its extracts, as functional food/ingredient with nutraceutical and pharmacological value.