Mn- and Cd-Contaminated Wild Water Spinach: in vitro Human Gastrointestinal Digestion Studies, Bioavailability Evaluation, and Health Risk Assessment

摘要

Human health may be at risk when consuming edible but metal-contaminated aquatic plants. This present study was conducted to evaluate the bioavailabilities of manganese (Mn) and cadmium (Cd) in metals-contaminated wild water spinach (WWS), Ipomoea aquatic Forssk. through in vitro human gastrointestinal digestions. Additionally, the health risks from consuming the plant were also assessed. Metals-contaminated hydroponic nutrient solutions were used to grow the plants under greenhouse conditions. The plants were harvested after seven days of metal exposure and their edible shoots (stems and leaves) underwent digestions simulated from the human gastrointestinal tract. A standard reference material (peach leaves, SRM 1547) was used to assess the precision and accuracy of the in vitro digestion studies. Results showed that the metal concentrations in plants increased when the treatment concentration increased; the metals concentrations were higher in the raw (RHS) samples than in the cooked (DHS and CHS) samples. The bioavailabilities of Mn and Cd were found to be higher in the intestinal extractions than in the gastric extractions. The health risk index (HRI) showed that the adults averagely aged 44 in Selangor, Malaysia was at risk if they consumed Mn-T1-contaminated cooked (CHS) WWS and Cd-contaminated raw (RHS) and cooked (CHS) WWS at T1 and T2 because their HRI values were more than 1.