Bisphosphonates are drugs widely used to treat bone disorders such as osteoporosis and bone metastases. Despite their clinical importance, the long-term use of bisphosphonates is linked to the onset of medication-related osteonecrosis of the jaw (MRONJ). This study aimed to assess in vitro cytoprotective effects of Arrabidaea chica Verlot extract, at 1 and 5 µg mL-1, associated with a fraction enriched with geranylgeraniol from Bixa orellana L., at 1, 7, and 15 µg mL-1, in keratinocytes exposed to zoledronic acid (ZA). Cells were submitted to assessments of MTT cell viability, antiproliferative activity, and clonogenic assay potential. With an association of A. chica at 1 and 5 µg mL-1 and a fraction enriched with geranylgeraniol at 15 µg mL-1, an increase was observed in cell viability of 73.5% and 71.1%, respectively. The antiproliferative activity showed this treatment was not able to increase the viability of tumor cells, while the clonogenic assay potential assessment showed the association with A. chica at the highest concentration tested (5 µg mL-1) was able to reverse the effects of ZA on the cells. This study provides data for a potential treatment for MRONJ, ensuring a better quality of life to patients who suffer from this comorbidity.

Keywords: Bisphosphonates; Natural products; Cell viability.