Cyperus rotundus L. alkaloid extracts enhance oncolytic Newcastle disease virus against digestive system neoplasms

Abstract

Digestive system cancers are common primary cancer in humans. Plants are an excellent source of compounds used in the treatment of different types of cancer. Virotherapy is a promising tool for fighting cancer because of its safety and selectivity. Thus, the present study proposed a new combination therapy consisting of secondary metabolite compounds (alkaloids) extracted from Cyperus rotundus L. and oncolytic Newcastle disease virus (NDV). The new combination was tested against three cancer cell lines (i.e., human rectal and esophagus cancer and mouse hepatocellular carcinoma) and a non-transformed rat embryo fibroblast cell line (REF). The MTT viability assay was used to analyze the possible synergism using the Chou–Talalay analysis method. The in vitro study showed that the combination therapy of NDV-alkaloid extract had synergistic enhanced anticancer activity on all the cancer cell lines tested. Moreover, combination therapy showed antagonism and low cytotoxic effect on the REF cell line. NDV-alkaloid treatment was found to upregulate p53 in comparison with each monotherapy alone, and thereby it is a possible explanation for the synergism. In conclusion, this study proposed a novel cancer therapy via the combination of C. rotundus L. (alkaloids) extract and oncolytic NDV, which may be a promising therapy for gastrointestinal tumors.