Preparation, characterization, in vitro digestion, and anti-ulcerative colitis activity evaluation of Pithecellobium clypearia polyphenol nanoliposomes

Pithecellobium clypearia Benth polyphenols (PCBPL) possess potent antioxidant and anti-inflammatory properties, making them promising agents for ulcerative colitis (UC) therapy. However, their clinical translation is hindered by poor water solubility, low stability, and limited bioavailability. To overcome these limitations, Pithecellobium clypearia Benth polyphenols liposomes (PCBPL-Lips) were prepared via thin-film hydration. The resulting PCBPL-Lips exhibited a high encapsulation efficiency of 89.31 ± 1.09%, an average particle size of 124.51 ± 7.61 nm, and a zeta potential of −31.62 ± 2.37 mV. Transmission electron microscopy confirmed their uniform particle distribution, spherical morphology, and smooth surfaces. Stability evaluations showed that PCBPL-Lips remained stable under various pH, temperature, and ionic strength conditions. In vitro digestion studies revealed a sustained-release profile, suggesting potential for prolonged therapeutic action. Biocompatibility assessments showed a hemolysis rate below 5% and cell viability above 80%, indicating excellent safety. In vitro activity assays demonstrated that liposomal encapsulation preserved the antioxidant activity of PCBPL and significantly enhanced its anti-inflammatory efficacy. In a murine model of UC, PCBPL-Lips alleviated clinical symptoms, reduced body weight loss, increased colon length, decreased spleen index and tumor necrosis factor-alpha (TNF-α) levels, and improved colonic tissue architecture. This study demonstrates that liposomal encapsulation markedly enhances the stability, bioavailability, and therapeutic efficacy of PCBPL, providing a promising strategy for its use in the treatment of inflammatory bowel diseases.