Water spinach (Ipomoea aquatic Forsk.) reduced the absorption of heavy metals in an in vitro bio-mimicking model system

This study was conducted to investigate the effect of water spinach on bioaccessibility and intestinal uptake of heavy metals (Arsenic (As), Cadmium (Cd), and Lead (Pb)) using an in vitro digestion model with Caco-2 cells. Aliquots of each heavy metal were co-digested with each part of water spinach (stem and leaf) and then cultured with Caco-2 intestinal cells for 1 h at 37 °C. Each heavy metal of As, Cd, and Pb was quantified using an ICP-OES. As the amount of stem and leaf (10, 50, 100, and 500 mg) of water spinach increased, bioaccessibility of As, Cd, and Pb decreased to 42.63%, 12.04%, and 26.17% by leaf and 30.37%, 43.27%, 40.07% by stem, respectively. Intestinal uptake of As, Cd, and Pb reduced to 65.8%, 25.7%, and 44.8% for leaf (500 mg) and 48.4%, 51.3%, and 64.3% for stem (500 mg), respectively, compared with the control without leaf and stem. The leaf from water spinach was the most effective for decreasing both bioaccessibility and cellular uptake of Cd.

► Leaf and stem from water spinach have an ability of chelating heavy metals. ► Leaf and stem from water spinach hinder the intestinal uptake of heavy metals. ► This study suggests that water spinach could be an excellent food source to reduce absorption of heavy metals. ► Intake of water spinach may result in lower health risk of exposure to heavy metals.