Chitosan-tripolyphosphate nanoparticles as Arrabidaea chica standardized extract carrier: synthesis, characterization, biocompatibility and antiulcerogenic activity.

Abstract

Natural products using plants have received considerable attention because of their potential to treat various diseases. Arrabidaea chica (Humb. & Bonpl.) Verlot is a native tropical American vine with healing properties employed in folk medicine for wound healing, inflammations and gastrointestinal colic. Applying nanotechnology to plant extracts has revealed an advantageous strategy for herbal drugs considering the numerous features that nanostructured systems offer, including solubility, bioavailability, and pharmacological activity enhancement. The present study reports the preparation and characterization of chitosan-sodium tripolyphosphate (CS-TPP) nanoparticles (NP) charged with Arrabidaea chica standardized extract (AcE). Particle size and zeta potential were measurements using a Zetasizer Nano. The NP morphological characteristics were observed using scanning electron microscopy. Our studies indicated that CS/TPP mass ratio of 5 and volume ratio of 10 were found to be the best condition to achieve the lowest NP sizes, with an average hydrodynamic diameter of 150 ±13 nm and zeta potential of +45 ± 2 mV. Particle size decreased with AcE addition (60 ± 10,2 nm), suggesting an interaction between extract`s composition and polymers. The NP biocompatibility was evaluated using human skin fibroblasts. AcE-NP demonstrated capability of maintaining cell viability at the lowest concentrations tested, stimulating cell proliferation at higher concentrations. Antiulcerogenic activity of AcE-NP was also evaluated with acute gastric ulcer experimental model induced by ethanol and indomethacin. Nanoparticles loaded with A. chica extract reduced the ulcerative lesion index using lower doses compared with the free extract, suggesting that extract encapsulation in chitosan nanoparticles allowed a dose reduction for gastroprotective effect. The AcE encapsulation offers an approach for further application of A. chica extract that could be considered a potential candidate for ulcer healing pharmaceutical systems. (AU)