A Phenolic Extract Obtained from Methyl Jasmonate-Treated Strawberries Enhances Apoptosis in a Human Cervical Cancer Cell Line

In the present study, we evaluated the effect of methyl jasmonate (MeJA) treatment on strawberry phenolic composition. Strawberry extracts contain a mixture of phenolic compounds possessing several biological properties. We demonstrated that these extracts were more effective in inducing apoptosis in HeLa cells compared to phenolic preparations derived from untreated strawberries. Treatment of strawberries with 0.5% MeJA resulted in increased polyphenols content (from 7.4 to 8.6 mM quercetin equivalents) and antioxidant properties (from 3.9 to 4.6 mM quercetin equivalents). The identification and quantification of phenolic compounds by liquid chromatography–mass spectrometry in the strawberry extracts showed that cyanidin glucoside, pelargonidin glucoside, and ellagic glucoside acid were significantly higher in strawberries treated with MeJA. Phenolic extracts from MeJA-treated strawberries significantly decreased the cell viability in HeLa cells, compared to extracts derived from untreated fruits. We hypothesized that the enhanced apoptotic activity of MeJA-treated strawberries was due to a synergistic or additive effect of different phenolic compounds present in the extract, rather than the activity of a single molecule.