Method for Isolating Hypericin from Hypericum perforatum and Preparing Its Micelles for Biomedical Applications

Hypericin (Hyp) is a naturally occurring photosensitizer (PS) exhibiting a broad spectrum of biological activities. However, its high hydrophobicity significantly limits its medical applicability. This study aimed to develop an efficient method for extracting Hyp from Hypericum perforatum L. biomass and to obtain its water-soluble micellar formulation. A protocol for Hyp isolation from the aerial parts of the plant was established, involving a preliminary defatting step using a Soxhlet apparatus, followed by ultrasonic-assisted extraction with acetone. The water-soluble formulation was prepared via the thin-film hydration method using the nonionic block copolymer Pluronic F-127. The resulting micelles demonstrated colloidal stability, with a mean hydrodynamic diameter of approximately 30 nm. A high Hyp loading efficiency was achieved, with an encapsulation efficiency (EE) of 95.4 ± 2.7%, yielding a concentration of 600.6 ± 16.6 µM within the micellar formulation. In vitro biological studies were performed using the murine GL261 glioblastoma cell line. The micellar Hyp formulation exhibited efficient time-dependent cellular accumulation and photoinduced cytotoxicity, with no observable dark toxicity. The proposed method enables the production of a stable Hyp formulation that retains its photosensitizing properties, thereby opening promising avenues for its application in photodynamic and sonodynamic therapies.