Pterodon pubescens seed extract induces the cell cycle arrest of leukemic cells by deregulating cyclin D1 and E2 mRNA levels.

Plant-derived compounds are important sources of effective anti-cancer agents. Pterodon pubescens is a native Brazilian plant popularly known for its anti-inflammatory and anti-arthritic effects. The ethanolic extract of its seeds (EEPp) is a viscous, brown and fragrant oil containing geranylgeraniol, farnesol, naphthalene, dimethyldodecatrienol and vouacapan diterpene derivatives, in addition to other compounds. This study investigated the in vitro anti-leukemic properties of EEPp using the resistant human leukemia cell line K562. The EEPp anti-proliferative effect was demonstrated by the inhibition of DNA synthesis and cell growth, and the induction of cell cycle arrest in the G(1) phase. Furthermore, cyclin E2 mRNA levels were down-regulated, while those of cyclin D1 were up-regulated. An EEPp anti-leukemic effect may have also triggered apoptosis, as it increased the number of shrunken cells and phosphatidylserine cell membrane exposure. These observations suggest that EEPp deregulates cyclin D1 and E2 expression, inducing cell cycle arrest and apoptosis of leukemic cells.