Bio-guided fractionation and iron chelating activity of agricultural residues

Iron overload is implicated in many disorders in the body such as heart failure, liver cirrhosis and fibrosis, gallbladder disorders, diabetes, arthritis, depression, infertility, and cancer. Even though synthetic chelating agents are available, they have several limitations such as poor oral bioavailability, short plasma half-life, high cost and numerous side effects. Therefore, the aim of this study is using agricultural residues as sources for alternative efficient, benign, and economic iron chelators of natural origin. Eighteen agricultural residues were screened for iron chelating activity using 2, 2'-bipyridyl assay. The results showed that the extract of Mangifera indica leaves had the highest iron chelation activity (69.7%), in comparison to ethylenediaminetetraacetic acid (EDTA) (70.3%) (standard iron chelator). The M. indica leaves extract was further investigated for its flavonoidcontent, phenolic content and antioxidant activity. The high concentration of phenolic (405.5µg/g expressed as gallic acid equivalent) and flavonoid (336.9 µg/g expressed as quercetin equivalent) phytochemicals in the extract, as well as its significant antioxidant capacity (96.95%) compared to ascorbic acid (91.90%) (standard antioxidant agent), suggested that the M. indica leaves could represent a good source for new iron chelating agents in iron overload disorders.