Toward Understanding the Anticancer Activity of the Phytocompounds from Eugenia uniflora Using Molecular Docking, in silico Toxicity and Dynamics Studies.

Background: The Surinam cherry, Eugenia uniflora belongs to the family Myrtaceae, an edible fruit-bearing medicinal plant with various biological properties. Several anticancer studies have been conducted on its essential oils while the non-essential oil compounds including phenolics, flavonoids, and carotenoids have not been fully investigated.

Purpose: Therefore, the study evaluated the in silico anticancer potentials of phenolic, flavonoid, and carotenoid compounds of E. uniflora against the MDM2 and Bcl-xL proteins, which are known to promote cancer cell growth and malignancy. The physicochemical parameters, validation, cytotoxicity, and mutagenicity of the polyphenols were determined using the SwissADME, pkCSM, ProTox-II, and vNN-ADMET online servers respectively. Lastly, the promising phytocompounds were validated using molecular dynamics (MD) simulation.

Results: An extensive literature search resulted in the compilation of forty-four (44) polyphenols from E. uniflora. Top-rank among the screened polyphenols is galloylastragalin, which exhibited a binding energy score of -8.7 and -8.5 kcal/mol with the hydrophobic interactions (Ala93, Val141) and (Leu54, Val93, Ile99), as well as hydrogen bond interactions (Tyr195) and (Gln72) of the proteins Bcl-xL and MDM2 respectively. A complete in silico toxicity assessment revealed that the compounds, galloylastragalin, followed by myricetin, resveratrol, p-Coumaroylquinic acid, and cyanidin-3-O-glucoside, were potentially non-mutagenic, non-carcinogenic, non-cytotoxic, and non-hepatotoxic. During the 120 ns MD simulations, the RMSF analysis of galloylastragalin- MDM2 (complex 1) and galloylastragalin- Bcl-xL (complex 2) showed the fewest fluctuations, indicating the conformational stability of the respective complexes.

Conclusion: This study has shown that polyphenol compounds of E. uniflora led by galloylastragalin, are potent inhibitors of the MDM2 and Bcl-xL cancer proteins. Thus, they may be considered as candidate polyphenols for further anticancer studies.