A bionic yeast for the colon-targeted delivery of curcumin in the treatment of inflammatory bowel disease

• Curcumin bionic yeast is assembled layer by layer from YCs, Alg and CS. • β-glucan enhanced the bio-accessibility and colon-targeting release ability of curcumin. • Curcumin bionic yeast has a more pronounced anti-inflammatory effect than curcumin does. • The AUC of curcumin bionic yeast increased with 11.8-fold. Inflammatory bowel disease (IBD) is a continuously increasing chronic inflammation, and it has been a worldwide health threat. Nevertheless, long-term treatments for IBD remain limited in clinical application. Curcumin is an ideal anti-oxidation and anti-inflammatory drug candidate for chronic inflammation and yet is still pharmacologically safe. However, its clinical application is limited by low solubility and poor bioavailability. To this end, we developed a colon-targeted curcumin carrier using β-glucan, sodium alginate (Alg) and chitosan (CS) named bionic yeast (BY) to improve the anti-inflammatory activity in IBD therapy. Saccharomyces cerevisiae -derived β-glucan greatly enhanced the bio-accessibility and colon-targeting release ability of curcumin. Moreover, the cell viability of bionic yeast demonstrated almost no toxicity on Caco-2 and RAW 264.7cells. The NO, iNOS, and proinflammatory factor including TNF-α, IL-1β, IL-6 were measured in LPS-induced RAW 264.7 cell line. These results indicated that bionic yeast containing β-glucan has a more pronounced anti-inflammatory effect than curcumin does. Therapeutic efficacy of bionic yeast was evaluated in DSS-induced IBD mouse model. It maintained the body weight, liver and spleen index triggered by DSS. The colon proinflammatory factor and inflammatory cell infiltration were significantly alleviated after receiving bionic yeast treatment. Furthermore, the bioavailability of bionic yeast was determined by pharmacokinetics. Compared with free curcumin, the concentration of bionic yeast increased with 11.8-fold in bloodstream and 14.1-fold in colon, demonstrating that bionic yeast is readily absorbed after oral administration. This bionic yeast delivery system combines the immune-enhancing properties of β-glucan with the colon-targeting capabilities of Alg and CS, bridging the gap in ‘natural carrier synergistic therapy’ and addressing the challenge of long-term management in acute bowel inflammation.