Phenolic Compound Composition and Biological Activities of Fractionated Soybean Pod Extract

Abstract

The objective of this study was to determine the potential of dry extracts from soybean pods as a source of bioactive compounds. The phenolic compound composition of the extract (E) and fraction (F1-F3) as well as their respective lipophilicity were analyzed by UPLC-ESI-QTOF-MS. The biological activity as measured by antioxidant and cytotoxic activity was also evaluated. The in vitro anticancer potential of the ethanolic extract and fraction of soybean pods was measured through MTT assay using human colorectal carcinoma (HTC-116) and prostate cancer (PC-3) cell lines. The F2 fraction, with medium lipophilicity, produced the most pronounced cytotoxic effect in PC-3 cells. Analysis of Pearson’s correlation demonstrated a high relationship between the content of phenolic compounds, the antioxidant activity of the extract and fractions, and cytotoxic activity towards PC-3 cells. UPLC-ESI-QTOF-MS analysis of soybean pod extract resulted in putative identification of 50 polyphenols belonging to three different chemical families (phenolic acids, flavonoids, and other polyphenols), the first time such an analysis has been performed. Among the fractions with variable lipophilicity, fraction F2 was the most abundant in phenolic compounds. This was confirmed in the quantitative analysis, as a result of which the highest total content of phenolic compounds was found in the extract (E) and fraction F2. Soybean pods might be useful material for obtaining preparations with anti-radical and anti-cancer properties. They can also be an active food additive or a component in dietary supplements.