HPLC-PDA/ESI-MS determination of the polyphenolic profile and evaluation of the cytotoxic effect of Tetraclinis articulata bark using in vitro and in silico methods

The present research aimed to establish the polyphenolic profile and to appraise the cytotoxic activity first by in vitro analyses, followed by a confirmatory in silico study to establish a stronger biochemical rationale for the activity of the ethyl acetate extract obtained from the bark of Tetraclinis articulata. Total phenolics and flavonoids of the ethyl acetate extract were quantified (phenolics, 65.30 mg gallic acid equivalents/g extract; flavonoids, 28.90 mg quercetin equivalents/g extract). A total of 22 polyphenolic compounds were identified in the ethyl acetate extract by HPLC-PDA/ESI-MS analysis. Tetraclinis articulata extract exerted a significant cytotoxic effect against a HeLa cell line (IC50 = 07.02 ± 1.15 μg/mL). The in silico analysis was in agreement with the in vitro study in which major constituents of ethyl acetate extract showed low binding energy and a correct mode of interaction in the active pocket of the enzyme (PDB: 4I5I). These results might be due to the synergistic action of constituents present in ethyl acetate extract or acting separately. This is the first report on the polyphenolic composition and cytotoxic activity of the extract from the bark of T. articulata.