Berberine-loaded PLGA nanoparticles alleviate ulcerative colitis by targeting IL-6/IL-6R axis.

Aims: The present study aims to develop a nano-delivery system that encapsulates berberine (BBR) into PLGA-based nanoparticles (BPL-NPs), to treat ulcerative colitis (UC). Furthermore, the therapeutic efficacy and molecular targeting mechanisms of BPL-NPs in the management of UC are thoroughly examined.

Methods: Emulsion solvent-driven methods were used to self-assemble BBR and PLGA into nanoparticles, resulting in the development of the nano-delivery system (BPL-NPs). The therapeutic effectiveness of BPL-NPs was evaluated using a dextran sulfate sodium (DSS)-induced model of ulcerative colitis in mice and a lipopolysaccharide (LPS)-induced model of inflammation in THP-1 macrophages. The interaction between Mφs and NCM-460 cells was investigated using a co-culture system. The molecular targeting ability of BPL-NPs in the treatment of UC was validated through in vitro as well as in vivo experiments.

Results: The BPL-NPs demonstrated a particle size of 184 ± 22.4 nm, enhanced dispersibility in deionized water, and a notable encapsulation efficiency of 31.1 ± 0.2%. The use of BPL-NPs clearly improved the clinical symptoms and pathological changes associated with UC in mice while also ensuring minimal toxicity. In addition, BPL-NPs improved intestinal epithelial cell apoptosis and enhanced the function of the intestinal barrier by inhibiting M1 Mφs infiltration and IL-6 signaling pathway in mice with UC. Furthermore, the BPL-NPs were found to selectively target the IL-6/IL-6R axis during the M1 Mφs-induced apoptosis of NCM460 cells.

Conclusion: The BPL-NPs were confirmed to harbor anti-inflammatory effects both in vitro and in vivo, along with enhanced water solubility and bioactivity. In addition, the precise targeting of the IL-6/IL-6R axis was confirmed as the mechanism by which the BPL-NPs exerted therapeutic effects in UC, as demonstrated in both in vitro as well as in vivo studies.