Chemical and Biological Characterization of Metabolites from Silene viridiflora Using Mass Spectrometric and Cell-Based Assays

Abstract

A comprehensive metabolite profiling of the medicinal plant Silene viridiflora using an UHPLC-ESI-MS/MS method is described for the first time. A total of 71 compounds were identified and annotated, the most common of which were flavonoids, triterpene glycosides, and ecdysteroids. The three major compounds schaftoside, 26-hydroxyecdysone, and silviridoside can be chosen as the markers for the assessment of the quality of S. viridiflora preparations. The methanol extract and a variety of metabolites identified in S. viridiflora were screened for their cytotoxic and Wnt pathway-inhibiting activities against triple-negative breast cancer (TNBC), the deadliest form of cancer in women. 2-Deoxy-20-hydroxyecdysone with submicromolar IC₅₀ was identified as a result. The structure-activity relationship derived from the data from the in vitro proliferation assay showed that the hydroxyl group present at position C-2 of steroid core reduces the ecdysteroids' cytotoxicity against cancer cells.

Keywords: Silene viridiflora; TNBC; UHPLC-MS; Wnt signaling; cytotoxicity; metabolite annotation.

Figure 1

Inhibitory effect at various (2–0.069 µM) concentrations of 2-deoxy-20-hydroxyecdysone (58) on cell lines BT-20 (A), HCC1395 (B), MDA-MB-231 (C), and HEK293 (D) (MTT test). Data are represented as an average ±SEM from N = 3 independent experiments, performed in duplicate for each concentration (n = 2). Statistical significance was assessed by one-way ANOVA with multiple comparisons and is shown as * p < 0.05, *** p < 0.001 (for each point within the indicated span).

Figure 2

Structure of tested ecdysteroids.

Figure 3

Summary of the SARs for the anti-proliferative activities of tested ecdysteroids.