Role of β-Cryptoxanthin as an Antioxidant and Its Ability to Bind with Transferrin

The potential nutraceutical benefits of carotenoids, which are versatile bioactive compounds, have been of great interest recently for its applications as dietary supplements. Carotenoids are red-orange coloured pigments which absorb light in the wavelength region of 400-550 nm. They are produced by plants, bacteria, algae and fungi and are abundantly distributed in the nature. In this study, our focus is on beta-cryptoxanthin (β-CRX), a yellow colored pro-vitamin A xanthophyll which is extracted from a previously isolated bacterium Kocuria marina DAGII grown in Brain Heart Infusion and sub-cultured in low cost dairy waste like whey and incubated at 25°C and 150 rpm for 5 days. The extracted beta-cryptoxanthin showed good radical scavenging activity and played a role in inhibition of lipid oxidation. Transferrin is a glycoprotein which plays a significant role in the mobilisation of iron in the body. It has two receptors TfR1 and TfR2 amongst which TfR1 binds to the iron-loaded transferrin. In cases of secondary hemochromatosis, HFE protein competes with transferrin to bind to TfR1 which leads to iron built up which is detrimental to the human body. Beta-cryptoxanthin was found to bind to Transferrin with a binding energy of -8.2 kcal/mol.