Lutein Emulsion Stabilized by a Food-Grade Biopolymer Enhanced Lutein Bioavailability and Improved Retinal Vessel Morphology in Neonatal Rats with Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a leading cause of blindness in infants, affecting 32% of hospitalized preterm infants. Oxidative stress, a primary pathogenic factor in ROP, triggers abnormal neovascularization of retinal vessels. Lutein, an antioxidant and the main component of macular pigment, is found in low levels in preterm infants and may help ameliorate ROP. However, its low bioavailability limits its application as a nutritional intervention. The study aimed to assess the effect of a lutein emulsion stabilized by a food-grade biopolymer on lutein bioavailability in neonatal rats with ROP and examine the effects of both unemulsified lutein and lutein emulsion on the disease. Neonatal rats were subcutaneously administered KRN 633 (10 mg/kg body weight) on postnatal days 7 and 8 (P7 and P8) to induce ROP. Neonatal rats that did not receive the treatment served as the control. From P9 to P21, both ROP and non-ROP rats were divided into 3 groups and given daily doses of olive oil, unemulsified lutein (2 mg/kg body weight lutein), or lutein emulsion (2 mg/kg body weight lutein). On P22, serum and tissues were collected. Lutein concentrations were measured using ultra-performance liquid chromatography, and retinal morphology was assessed using immunohistochemistry. Rats treated with lutein emulsion had significantly higher serum and tissue lutein concentrations than those receiving unemulsified lutein. Morphological assessments showed that ROP rats had more tortuous arteries, increased capillary density, enlarged vessels, reduced astrocyte density, and decreased neuronal cells. Both unemulsified lutein and lutein emulsion alleviated these abnormalities, with lutein emulsion showing superior efficacy in restoring neuronal cell levels to normal in the peripheral retina. Lutein, in both unemulsified and emulsified forms, effectively inhibited ROP progression in neonatal rats. The biopolymer-based lutein emulsion showed promise as a delivery system to enhance lutein bioavailability and mitigate ROP in preterm infants.