title: Anticancer effects of geopropolis produced by stingless bees on canine osteosarcoma cells in vitro.
abstract: Geopropolis is produced by indigenous stingless bees from the resinous material of plants, adding soil or clay. Its biological properties have not been investigated, such as propolis, and herein its cytotoxic action on canine osteosarcoma (OSA) cells was evaluated. OSA is a primary bone neoplasm diagnosed in dogs being an excellent model in vivo to study human OSA. spOS-2 primary cultures were isolated from the tumor of a dog with osteosarcoma and incubated with geopropolis, 70% ethanol (geopropolis solvent), and carboplatin after 6, 24, 48, and 72 hours. Cell viability was analyzed by the crystal violet method. Geopropolis was efficient against canine OSA cells in a dose- and time-dependent way, leading to a distinct morphology compared to control. Geopropolis cytotoxic action was exclusively due to its constituents since 70% ethanol (its solvent) had no effect on cell viability. Carboplatin had no effect on OSA cells. Geopropolis exerted a cytotoxic effect on canine osteosarcoma, and its introduction as a possible therapeutic agent in vivo could be investigated, providing a new contribution to OSA treatment.
authors.affiliation: Surgery and Orthopedics Department, Medical School, São Paulo State University (UNESP), 18618-970 Botucatu, SP, Brazil.
authors.forename: Naiara Costa
authors.initials: NC
authors.lastname: Cinegaglia
authors.forename: Paulo Ricardo Oliveira
authors.initials: PR
authors.lastname: Bersano
authors.forename: Maria José Abigail Mendes
authors.initials: MJ
authors.lastname: Araújo
authors.forename: Michelle Cristiane
authors.initials: MC
authors.lastname: Búfalo
authors.forename: José Maurício
authors.initials: JM
authors.lastname: Sforcin