Phytotherapy has been used to treat a different type of diseases including cancer for a long time, and it was a source for different active anti-tumor agents. Oncolytic Newcastle disease virus (AMHA1) are very promising anti-tumor therapy. Nevertheless, NDV-based monotherapeutics have not been very useful to some resistant tumors. Thus, the efficiency of oncolytic NDV must enhance by combining NDV with other novel therapies. The current study aimed to determine the possibility of improving the oncolytic effect induced by NDV through Rheum ribes rhizomes extract administration in vitro and in vivo. Methods, the in vitro study include exposure of the crude extract of Rheum ribes alone or NDV alone or combination of both agents for 72 h. The cancer cells tested were murine mammary adenocarcinoma AMN3, Human Rhabdomyosarcoma RD, and Human Glioblastoma AMGM5, and using rat embryo fibroblast REF as normal control cells. MTT cell viability assay was used and analyzed for possible synergism using the Chou-Talalay analysis method. In vivo experiment included study the combination and the monotherapeutic modalities in the transplanted murine mammary adenocarcinoma AM3 line and tumor sections analyzed by histopathology. Results, Combination therapy of NDV-R. ribes showed enhanced oncolytic activity on cancer cells. With no cytotoxicity on normal cells. In vivo study showed that monotherapeutic modalities had lower growth inhibitory effect on transplanted tumors in mice in compare to combination therapy. Histopathological examination revealed the broader area of necrosis in tumors treated by combination therapy. In conclusion, the novel combination recommended for clinical application for cancer therapy.
Keywords: Combination therapy; Glioblastoma; Mammary adenocarcinoma; Newcastle disease virus; Rhabdomyosarcoma; Rheum ribes.