POTENTIAL CYTOTOXIC AND ANTIANGIOGENIC PROPERTIES OF EHRETIA MICROPHYLLA LEAF ETHANOLIC EXTRACT THROUGH THE MODULATION OF MEK AND VEGFR 2

Abstract

Ehretia microphylla (E. microphylla) leaf is commonly consumed as herbal tea, known for its various benefits, such as anti-inflammatory, anti-mutagenic, anti-mitotic, antiproliferative, and anticancer. Two significant aspects of its anticancer potential, namely the intracellular signaling and angiogenic mechanism, remain elusive. This paper investigated the cell toxicity and antiangiogenic mechanism of E. microphylla leaf ethanolic extract (EMLEE). There were three experiments employed in this study. In the in vitro set-up, the human hepatoma cell line (HepG2) was examined after treatments with doxorubicin or various concentrations of EMLEE. For the in-ovo experiment, the 3-day-old duck embryo was observed for its degree of vascularization after injecting it with either EMLEE, 1% dimethyl sulfoxide (DMSO), or none. In the in silico study, the known compounds present in E. microphylla identified from various literatures available in PubChem were assessed for their predicted oral bioavailability. The candidate lead compounds were docked to selected proteins associated with intracellular signaling and angiogenesis. The top binding compounds were visualized along with their respective docked protein crystal structures. Findings show that the LC50 of EMLEE is about 1.1 mg/ml, diminishing blood vessel formation in the treated embryo by 57%. Out of the 58 known compounds, only 29 followed Lipinski's rule of five, indicating high predicted oral bioavailability. Additionally, only 8 of these compounds demonstrated high binding affinity with the selected proteins. Most of the compounds have a high binding affinity with MEK from intracellular signaling, whereas VEGFR2 for angiogenesis. Also, caffeic anhydride and apigenin bind to most of the selected proteins. Altogether, the high binding affinity of the lead compounds with the selected proteins, particularly MEK and VEGFR2, may explain the cytotoxic and antiangiogenic properties of EMLEE.

Keywords

• ehretia microphylla
• cytotoxicity
• angiogenesis
• intracellular signaling
• molecular docking