Evaluating Astaxanthin Bioavailability, and a New Technology for Improving it, Using Natural Food Materials Only

Astaxanthin (AX) is a red xanthophyll carotenoid found mainly in algae (notably Haematococcus Pluvialis microalga) and marine animals. AX is a stronger antioxidant than vitamin E and β-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 drugs), 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 (OO). The average particle diameters after preparation were 0.29, 0.29, and 1.76 μm, and after freeze-drying and reconstitution 0.17, 0.07, and 6.93 μm, 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.

Inclusion criteria

• Healthy volunteers
• Aged 18 - 26
• Normal physical examination
• Normal electrocardiogram (E.C.G.)
• Normal laboratory profile

Exclusion criteria

• Any active medical illness (e.g. liver disease, kidney disease, or diabetes, intestinal malabsorption, hypercalcemia)
• Lactose intolerance
• Food allergies
• Excessive alcohol use (over 40 ml/day)
• Pregnant or breast-feeding
• Hyperlipidemia (LDL>130, triglycerides>200)
• Regular medication use
• Obesity (BMI>30 kg/m2)
• Use of multivitamins, or carotenoid supplements during the past month prior to the study
• Current smoking