Abstract:The optimal conditions for ultrasonic-assisted cellulase extraction of bioactive polysaccharides from alpiniae oxyphylla fructus (AOF) were clarified using response surface methodology and artificial neural network coupled with genetic algorithm. The optimized conditions were a solvent-to-solid ratio of 20 mL/g, cellulase mass fraction of 4%, and ultrasonic power of 300 W for 20 min, which yielded a total polysaccharide extraction of 4.20%. Fourier transform infrared spectra revealed that the extracted sample had polysaccharide characteristic absorption peaks containing uronic acid and pyranose rings. The results of in vitro antioxidant assays showed that the total antioxidant capacity of AOF polysaccharides was 80.76 μmol TE/mL at 300 μg/mL and the ferric reducing antioxidant power was 133.6 μmol FeE/mL. To further evaluate the biological activity of AOF polysaccharides, a zebrafish colitis model was established using 2,4,6-trinitrobenzene sulfonic acid. The results showed that AOF polysaccharides prepared via ultrasonic-assisted cellulase extraction significantly promoted the total antioxidant activity, decreased the expression of the proinflammatory factor interferon-γ, increased the expression of the anti-inflammatory factor interleukin-10, and decreased the production of nitric oxide in zebrafish with colitis. These results indicate that the AOF polysaccharides have anti-inflammatory and antioxidant effects, providing a theoretical basis for the development of AOF products.
