Natural compounds in the treatment of osteosarcoma: just chemotherapy adjuvants? or is there much more?

Osteosarcoma is the most common type of bone tumor. Different therapeutic approaches are used in the management of osteosarcoma, where surgery is most often performed, often preceded and followed by chemotherapy, which however has serious short- and long-term side effects. Recently, much attention has been paid to natural compounds that can determine cell death of tumor. Some have a direct cytotoxic effect, and they also can reduce tumor and metastatic activity. Furthermore, it described how these molecules can also interact with elective chemotherapy against osteosarcoma. In this review, we have analysed the last decade literature, highlighting both the studies that have a direct cytotoxic effect on osteosarcoma, and those that are used as adjuvants to chemotherapy, allowing to reduce treatment doses, limiting the side effects. The comparison between the different studies have led to relevant considerations on the study standardization.