Epicatechin-Loaded Nanocapsules: Development, Physicochemical Characterization, and NLRP3 Inflammasome-Targeting Anti-Inflammatory Activity

Epicatechin is a flavonoid of the catechin subclass, found in fruits and medicinal plants such as açaí and green tea, widely studied for its anti-inflammatory properties. However, flavonoids often present chemical instability, low aqueous solubility, and poor bioavailability, limiting their therapeutic potential. This study aimed to incorporate epicatechin into nanocapsules to improve its applicability and evaluate whether the formulation maintains its anti-inflammatory effects via modulation of the NLRP3 inflammasome. Nanocapsules containing 0.25 mg/mL of epicatechin (NC-ECs) were prepared with Eudragit L-100 using interfacial deposition of a preformed polymer. The formulations were characterized for particle size, polydispersity index, zeta potential, and pH, as well as thermal stability over 45 days. Encapsulation efficiency and drug content were determined by high-performance liquid chromatography (HPLC), and morphology analyzed by atomic force microscopy (AFM). Cytocompatibility was assessed in VERO cells, and anti-inflammatory activity was investigated in THP-1-derived macrophages stimulated with LPS + nigericin. The NC-ECs displayed suitable physicochemical properties, high encapsulation efficiency (96%), and full drug loading. The formulation also showed good cytocompatibility and preserved anti-inflammatory activity through NLRP3 inflammasome modulation at low concentrations. These findings indicate NC-ECs as a promising nanotechnological strategy for treating inflammatory diseases involving NLRP3, highlighting its potential contribution to nanomedicine.