The in vitro cytotoxic efficacy of plant latex from Pergularia tomentosa L. was studied using five human cancer cell lines: HeLa cells (cervical carcinoma cells), A-549 (lung carcinoma), Panc-1 (pancreatic carcinoma cells), MDA-MB-231 (metastatic mammary adenocarcinoma), and MRC-5 (lung fibroblast cell line) cells. The phytonutrient content of plant latex was identified using the liquid chromatography/mass spectra-quadrupole time of flight (LC/MS-QTOF) technique. In silico studies of polyphenols were carried out to clarify the potential mode of action of the plant latex's constituents. The treatment of different tumor cell lines with different concentrations of plant latex revealed a potent efficacy on the human lung carcinoma cell line (A-549) (IC50 = 3.89 µg/mL) compared with that with vinblastine as a positive control (IC50 = 7.12 µg/mL). The effect of the potent concentration of plant latex on the A-549 cell line induced cell arrest, upregulated the expression of pre-apoptotic markers, and downregulated the expression of antiapoptotic markers. Seven identified polyphenols were selected for the in silico study. A docking assessment using the epidermal growth factor receptor kinase (EGFRk) and eltronib as a positive control showed a higher affinity for the enzyme receptor of the selected polyphenols, except for methyl orsellinate and ginkgotoxin. The ADMET assessment demonstrated the inhibitory effect of the polyphenols on CYP450, except for ouabagenin and xanthyletine. The selected polyphenols obey Lipinski's drug-likeness with no significant toxicity effect. In conclusion, the plant latex of P. tomentosa L. showed cytotoxic activity on the A-549 cell line, and the selected polyphenols showed a promising prodrug agent with a low profile of toxicity in the study.
Keywords: Pergularia tomentosa L. latex; apoptosis; cytotoxicity; docking; pharmacokinetic.