Evaluating “Helleborus cyclophyllus” extract’s cytotoxic activity against malignant and normal cell lines? preliminary evidence of gastric acid resistance, and a promising therapeutic window

Abstract

Helleborus cyclophyllus is an ancient pharmaceutical plant that exhibits remarkable in vitro cytotoxic activity against malignant cell lines. In the present study, we evaluated the cytotoxic activity of Helleborus cyclophyllus dried powdered rhizome’s aqueous extract in both malignant (PC3, TPC1, K1 ) and normal ( Nthy-ori 3.1) cell lines. Our results demonstrated a promising therapeutic window, as normal cell lines exhibited significantly higher (x 10) IC50 than malignant cell lines. Gastric acid did not adversely affect Helleborus cyclophyllus extract’s cytotoxic activity as previous incubation in 1.0 M HCl acid did not result in IC50 values escalation. Finally, high extracellular lactic acid concentration resulted in Helleborus cyclophyllus extract’s cytotoxic activity amplification, whereas the presence of sodium lactate adversely affected cytotoxicity, revealing a possible indirect potential role for aerobic glycolysis to the clinically observed inadequacy of per os Helleborus cyclophyllus administration in cancer treatment.