New Strategies for the Delivery of Some Natural Anti-oxidants with Therapeutic Properties

Nature offers tremendous potential in the medicine field. Natural antioxidant molecules inhibit or quench free radical reactions and delay or inhibit cellular damage. In the last few years, researchers have been focusing on the health benefits of natural products. Particularly some dietary nutrients, such as curcumin, crocin, resveratrol, quercetin, coenzyme Q10, vitamin C, as well as some polysaccharides have been evaluated for their numerous and unique therapeutic properties. This review focuses on examples of pharmaceutical applications of natural anti-oxidants, with special regards to their encapsulation in micro- and nano- delivery systems. In vitro and in vivo studies have been conducted to investigate the physicochemical and pharmacological properties of different delivery systems containing antioxidant molecules. For instance, ethosomes, organogels, monoolein aqueous dispersions and solid lipid nanoparticle have been considered. It was found that micro and nanoencapsulation strategy can improve the solubility of lipophilic molecules and the chemical stability of labile antioxidants, thus prolonging their efficacy. In vitro and in vivo studies have highlighted that antioxidant encapsulation prolongs release kinetics, bioavailability and antioxidant effects. Noticeably, some encapsulated antioxidants effectively inhibit cancer cell proliferation, cell migration and colony formation, thus suppressing cancer progression.