Overexpression of the Anthocyanidin Synthase Gene in Strawberry Enhances Antioxidant Capacity and Cytotoxic Effects on Human Hepatic Cancer Cells

Food fortification through the increase
and/or modulation of bioactive
compounds has become a major goal for preventing several diseases,
including cancer. Here, strawberry lines of cv. Calypso transformed
with a construct containing an anthocyanidin synthase (ANS) gene were produced to study the effects on anthocyanin biosynthesis,
metabolism, and transcriptome. Three strawberry ANS transgenic lines (ANS L5, ANS L15, and ANS L18) were analyzed for
phytochemical composition and total antioxidant capacity (TAC), and
their fruit extracts were assessed for cytotoxic effects on hepatocellular
carcinoma. ANS L18 fruits had the highest levels of total phenolics
and flavonoids, while those of ANS L15 had the highest anthocyanin
concentration; TAC positively correlated with total polyphenol content.
Fruit transcriptome was also specifically affected in the polyphenol
biosynthesis and in other related metabolic pathways. Fruit extracts
of all lines exerted cytotoxic effects in a dose/time-dependent manner,
increasing cellular apoptosis and free radical levels and impairing
mitochondrial functionality.