β Lapachone blocks the cell cycle and induces apoptosis in canine osteosarcoma cells

Abstract

Osteosarcoma is a malignant tumor of primitive bone cells with a high incidence in dogs and humans. The need for more effective drugs with less adverse consequences has pushed the development of chemotherapeutic agents from plants and other natural sources. The aim of this study was to verify the cytotoxic effects of β-lapachone, a compound present in the sawdust of Tabebuia sp. (popularly known as ipê) wood, on canine osteosarcoma cells subcultured and treated in different concentrations (0.1μm, 0.3μm e 1.0μm) and exposure times (24h, 48h e 72h). Results were obtained through Trypan blue dye exclusion, tetrazolium reducing method, cell survival assay, Annexin V-FITC and Propidium Iodine labeling, JC-1 dye labeling and cell cycle kinetics e analysis. The group treated with 0.3μm β-lapachone presented higher decrease in cell viability (80.27%, 24h, 47.41%, 48h and 35.19%, 72h) and greater progression of cytotoxicity (19.73%, 24h, 52.59%, 48h and 64.81%, 72h). The lower IC50 (0.180μm) was verified in the group treated for 72 hours. Cell growth after treatment decreased as concentration and time of exposure increased, with 0.50% survival fraction at the concentration of 1.0μm. Initial apoptosis was the most frequent type of cell death in all groups, reaching bottom in the 24-hour group treated with 0.1μm (4.26%) and peaking in the 72-hour group treated with 1.0μm (85.89%). Mitochondrial depolarization demonstrated a dose-dependent phenomenon, indicating the intrinsic apoptosis. Cell growth inhibition by blocking cell cycle in the G0/G1 phase related to the exposure the time. β-lapachone is cytotoxic for canine osteosarcoma cells, induces apoptosis and promotes cell cycle arrest in G0/G1 phase.

Crude extract of Jatobá leaves promotes canine osteosarcoma cell D17 proliferation

“…Herein, the ratio of positive staining of mutant p53 was higher in the groups treated with EBFG, with a significant difference in the EIS of that protein, according to the increased EBFG concentration. The opposite result was found in D17 cells treated with beta-lapachone [ 2 ], curcumin [ 40 ], and the ethanol extract of pequi peel [ 41 ], where the expression of mutant p53 decreased with increasing dosages and exposure time.…”

Cytotoxicity assessment of beta-lapachone in endothelial cells

“…This substance induced autophagy and suppressed the migration and invasion of HNE1 nasopharyngeal carcinoma cells (Han, Shi, & Li, 2019). In addition to the studies regarding human species, the cytotoxic action of this substance has recently been demonstrated in canine osteosarcoma cells (Cruz et al, 2018). The mechanism of action was the induction of intrinsic apoptosis, by rupturing the mitochondrial membrane potential and blocking the cell cycle in the G0/G1 phase.…”

“…In other words, this substance likely has antineoplastic activity, with selective non-cytotoxic action on non-neoplastic labile cells. BLP induces death in cancer cells through apoptosis, necrosis and autophagy, with the potential to treat neoplasms (Pinto & Castro, 2009;Cruz et al, 2018). The induction of cell death by necroptosis in SK-Hep1 cells of human hepatocellular carcinoma has recently been demonstrated (Park et al, 2014).…”

“…In addition, BLP can inhibit the topoisomerase complex, which allows the functions of transcription, repair, replication, and structuring of the chromosome to occur normally. By inhibiting the topoisomerase-DNA complex, checkpoints are formed in the cell cycle, which induce the death of malignant cells (Kleiner & Silva, 2013).Due to the activity of inhibition of DNA topoisomerase I, which is an enzyme that plays an important role in DNA replication and packaging processes, studies on BLP's antineoplastic action in prostate, ovarian, breast, myeloma, lung, canine osteosarcoma and liver cancers have been carried out (Pardee et al 2002;Kung, Lu, & Chau, 2014;Cruz et al, 2018). In cancer cells, BLP triggers the mechanisms of apoptosis, autophagy, and cell death by necrosis (Park et al, 2014).…”