Enhancing the Oral Bioavailability of Natural Astaxanthin Using Plantbased Micro- and Nano-Encapsulation Materials: Results of an in Vitro Evaluation and a Crossover Study in Humans

Astaxanthin (AX) is a red xanthophyll carotenoid found mainly in algae (notably Haeniatococcus Pluvialis microalga) and marine animals. AX is a stronger antioxidant than vitamin E and 0-carotene but has very low oral bioavailability. The purpose of this study was to develop a potato protein (PP)-based delivery system for increasing oral bioavailability of lipophilic bioactives (nutraceuticals and drags), using AX as a model, and to evaluate the system in vitro and in vivo in a crossover clinical study in human volunteers. Three different formulations were prepared, encapsulating AX oleoresin (AXO) with (1) PP only, (2) PP+lecithin (LEC), and (3) PP+olive oil (00). The average particle diameters after preparation were 0.29, 0.29, and 1.76 pm, and after freeze-drying and reconstitution 0.17, 0.07, and 6.93 pm, respectively. In vitro bioaccessibility was 33,47, and 69%, respectively, versus 16% only for the raw AXO. In a randomized, double-blind, crossover study in human subjects, the PP-OO-AX formulation had a 4.8-fold higher median plasma AX area under the concentration-over time curve (AUC; P<0.001) compared to the raw AXO formulation. In conclusion, a non-allergenic, vegan, PP-based delivery system made of “all-natural ingredients” offers a great promise for increasing oral bioavailability of lipophilic bioactives such as AX, for the enrichment of food and for dietary supplements, or oral delivery of lipophilic drugs.