Chemical Constituent Profiling of Phyllostachys heterocycla var. Pubescens with Selective Cytotoxic Polar Fraction through EGFR Inhibition in HepG2 Cells

Different extracts of the Bamboo shoot skin Phyllostachys heterocycla var. pubescens were screened against panel of cancer cell lines and normal one. The cell viability results exhibited that the ethyl acetate extract showed the least vitality percentage of 2.14% of HepG2 cells. Accordingly, it was subjected to chromatographic separation, which resulted in the isolation of a new natural product; 7-hydroxy, 5-methoxy, methyl cinnamate (1), together with four known compounds. The structures of the pure isolated compounds were deduced based on different spectroscopic data. The new compound (1) was screened against the HepG2 and MCF-7 cells and showed IC50 values of 7.43 and 10.65 µM, respectively. It induced apoptotic cell death in HepG2 with total apoptotic cell death of 58.6% (12.44-fold) compared to 4.71% in control by arresting cell cycle progression at the G1 phase. Finally, compound 1 was validated as EGFR tyrosine kinase inhibitor in both enzymatic levels (IC50 = 98.65 nM compared to Erlotinib (IC50 = 78.65 nM). Finally, in silico studies of compound 1 through the molecular docking indicated its high binding affinity towards EGFR protein and the ADME pharmacokinetics indicated it as a drug-like.