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

Abstract

Curcumin is a polyphenol extracted from the roots of the Curcuma longa plant. 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 and proliferation of primary cultures of Schwann cells. The use of nanoparticles as delivery systems has been shown to be 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), which we characterized by transmission and scanning electron microscopy. We analyzed the curcumin-PDA turnover with UHPLC-MS, and describe two different hydrophobic forms of curcumin, released at different times from their PDA-carrier. An increased cell viability and proliferation was observed in endoneurial fibroblast primary cell culture, when a low dose of curcumin-PDA was steadily supplied by prolonged periods. Furthermore, PDA alone as a vehicle showed no effect on viability and proliferation, in the same conditions. 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.