Characterization, digestive properties and glucose metabolism regulation of curcumin-loaded Pickering emulsion

Curcumin, a polyphenolic compound with antioxidant and hypoglycemic properties, has limited applications due to low stability and poor oral bioavailability. This study aimed to overcome these challenges by developing stable oil-in-water Pickering emulsions with curcumin and evaluating their stability and digestive characteristics. Using a T2DM mouse model, we further examined the effects of curcumin-loaded Pickering emulsions on glucose metabolism. The emulsions demonstrated high curcumin encapsulation efficiency (96.72 % ± 2.15 %) and minimal average droplet size. Both emulsions showed stable zeta potential, favorable rheological properties, and strong environmental and storage stability, lasting up to 60 days. In vitro digestion studies indicated that the Pickering emulsion substantially improved curcumin bioavailability (25.48 %-36.43 %) and increased antioxidant and hypoglycemic activity compared to oil-soluble curcumin, both before and after digestion. In animal experiments, the curcumin-loaded Pickering emulsion enhanced fasting blood glucose, glucose tolerance, and insulin resistance in T2DM mice, compared to the untreated model group. It also supported tissue repair in the pancreas, liver, and colon, reduced oxidative stress in the liver, activated the PI3K/Akt signaling pathway, and favorably influenced gut microbiota and short-chain fatty acids. These findings suggest that Pickering emulsions are an effective delivery system for curcumin in functional foods, supporting their application in curcumin-based product development.