Antioxidant and antiproliferative properties of extracts from spinach grown under low oxygen availability

A fruit and vegetable rich diet plays a protective role on human health, reducing the risk of major chronic diseases including cancer. Cancer cells are known to have an unbalance in their redox state, with a higher amount of ROS, thus being more susceptible to any additional oxidative stress. We studied the possible antiproliferative and antioxidant activity of spinach leaf juice from plants subject to hypoxic stress on the HT29 human colorectal adenocarcinoma cell line. The antiproliferative activity was evaluated on a counting chamber of a hemocytometer in order to evaluate the number of cells in active proliferation. The Trypan blue exclusion method was used to determine cytotoxicity. The antioxidant activities were assessed through the alkaline version of the Comet assay, evaluating the DNA damage on 24 h pre-treated HT29 cells. We found that hypoxic spinach leaf extract have a significant antioxidant and protective effect on HT29 cell line when cells are treated with H2O2. The extract exhibits also an antiproliferative effect on the same cells, markedly enhanced when coming from 24 hours hypoxic spinach leaves.