More Than Pigments: The Potential of Astaxanthin and Bacterioruberin-Based Nanomedicines

Abstract

Carotenoids are natural products regulated by the food sector, currently used as feed dyesand as antioxidants in dietary supplements and composing functional foods for human consumption.Of the nearly one thousand carotenoids described to date, only retinoids, derived from betacarotene, have the status of a drug and are regulated by the pharmaceutical sector. In this review,we address a novel field: the transformation of xanthophylls, particularly the highly marketedastaxanthin and the practically unknown bacterioruberin, in therapeutic agents by altering their pharmacokinetics,biodistribution, and pharmacodynamics through their formulation as nanomedicines.The antioxidant activity of xanthophylls is mediated by routes different from those of the classicaloral anti-inflammatory drugs such as corticosteroids and non-steroidal anti-inflammatory drugs(NSAIDs): remarkably, xanthophylls lack therapeutic activity but also lack toxicity. Formulated asnanomedicines, xanthophylls gain therapeutic activity by mechanisms other than increased bioavailability.Loaded into ad hoc tailored nanoparticles to protect their structure throughout storage andduring gastrointestinal transit or skin penetration, xanthophylls can be targeted and delivered to selectedinflamed cell groups, achieving a massive intracellular concentration after endocytosis of smalldoses of formulation. Most first reports showing the activities of oral and topical anti-inflammatoryxanthophyll-based nanomedicines against chronic diseases such as inflammatory bowel disease, psoriasis,atopic dermatitis, and dry eye disease emerged between 2020 and 2023. Here we discuss in detailtheir preclinical performance, mostly targeted vesicular and polymeric nanoparticles, on cellularmodels and in vivo. The results, although preliminary, are auspicious enough to speculate upon theirpotential use for oral or topical administration in the treatment of chronic inflammatory diseases.