Low hormetic dose of curcumin-PDA nanoparticles improves viability and proliferation in cell culture

Abstract

Abstract Curcumin is a polyphenol extracted from Curcuma longa’s roots. Low doses of curcumin are related to anti-inflammatory, antioxidant, and neuroprotective effects, while high doses are used for their lethality. This diversity of behaviors allows us to understand curcumin as a compound with hormetic action. Due to its hydrophobic character, curcumin is solubilized in organic compounds, about which we have recently reported undesirable effects on the viability of primary Schwann cell cultures. Using nanoparticles as delivery systems is a successful strategy for many compounds. In the present work, we describe the structure of Polydopamine (PDA) nanoparticles, loaded or not with a low dose of curcumin (0.05 µM, curc-PDA), which we characterized by transmission and scanning electron microscopy. We analyzed the curc-PDA turnover with UHPLC-MS and described two different hydrophobic forms of curcumin, released at other times from their PDA carrier. Increased cell viability and proliferation were observed in endoneurial fibroblast primary cell culture when curc-PDA was steadily supplied for prolonged periods. Furthermore, PDA alone showed no effect on viability and proliferation. These results confirm the beneficial properties of curcumin at very low doses, thus widening its therapeutic window thanks to the increased bioavailability provided by our biological approach.