Objective To prepare sinomenine nanoemulsion (Sin-NE) co-stabilized by Bletilla striata polysaccharide and glycyrrhizic acid, systematically characterize its properties, investigate its stability and drug release behavior, and further evaluate its anti-inflammatory effects through in vitro experiments. Methods The Sin-NE was prepared using the ultrasonic emulsification method. Its morphology, particle size, polydispersity index (PDI), and ζ potential were observed and determined. Optimal formulation parameters were screened via single-factor and orthogonal experiments, followed by formulation validation. pH value, turbidity, viscosity, encapsulation efficiency, and drug loading capacity were measured. Stability was investigated under centrifugation, storage, dilution, and heating conditions was evaluated, and in vitro drug release behavior was investigated. A RAW264.7 cell inflammation model was established to validate the effects of the Sin-NE on nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Results The optimized formulation comprised 3% Coicis Semen oil, 0.5% combined emulsifiers, a 1∶9 mass ratio of Bletilla striata polysaccharide to glycyrrhizic acid, 10 min of ultrasonic treatment, and 325 W ultrasonic power. The resulting Sin-NE exhibited an average particle size of (145.30 ±2.35) nm, ζ potential of (-39.51 ±0.43) mV, PDI of 0.095 ±0.022, and pH value of 3.990 ±0.033. Encapsulation efficiency and drug loading capacity reached 88.78% and 26.14 mg/g, respectively. The nanoemulsion demonstrated excellent stability under centrifugation, storage, dilution, and heating conditions and displayed sustained-release characteristics. In vitro, it significantly inhibited NO release and effectively reduced IL-6 and TNF-α levels in inflamed cells. Conclusion The Sin-NE significantly enhances sinomenine’s bioavailability and anti-inflammatory activity, providing experimental evidence for developing novel traditional Chinese medicine nanoemulsion formulations.

Bletilla striata polysaccharide  /  sinomenine  /  glycyrrhizic acid  /  nanoemulsion  /  anti-inflammatory activity  /  ultrasonic emulsification method  /  interleukin-6  /  tumor necrosis factor-α