该研究探讨了优化超声波辅助复合酶法从长茎葡萄蕨藻藻渣中提取多糖的工艺条件，并探究其降脂功能。以长茎葡萄蕨藻藻渣为原料，在单因素试验的基础上，利用响应面法优化提取多糖的最佳参数；通过与胆酸盐的结合能力在体外评价长茎葡萄蕨藻藻渣多糖降脂作用；采用高脂饮食诱导小鼠建立高脂血症模型，以长茎葡萄蕨藻藻渣多糖灌胃干预，4周后评价其体内降脂效果。长茎葡萄蕨藻藻渣多糖的最佳提取条件为复合酶（中性蛋白酶: 木聚糖酶: 纤维素酶=1:1:1）质量分数2.5%，酶解温度48 ℃，酶解时间123 min，多糖得率可达36.62%，质量分数为87.20%。长茎葡萄蕨藻藻渣多糖（10 mg/mL）与胆酸钠、脱氧胆酸钠、牛磺胆酸钠和甘氨胆酸钠结合率分别为86.56%、89.47%、84.26%和64.68%。与模型组比较，长茎葡萄蕨藻藻渣多糖（200、400 mg/kg）显著减轻小鼠体质量（11.29%、15.38%），降低脂肪系数（4.07%、3.18%）及血清中TG（59.87%、68.42%）、TC（28.24%、39.08%）和LDL-C（34.93%、49.28%）水平，提高HDL-C（52.67%、99.00%）水平。优化得到的超声波辅助复合酶法提取长茎葡萄蕨藻藻渣多糖的条件合理可靠，所得多糖有较强的结合胆酸盐能力，对高脂饮食诱导的高血脂症具有预防作用。

The optimal conditions for ultrasound-assisted enzymatic extraction of polysaccharides from the algal residue of Caulerpa lentillifera were determined and the lipid-lowering effects of the extracted polysaccharides were investigated. Single-factor experiments and the response surface methodology were used to optimize the extraction parameters. The in vitro lipid-lowering effects of the extracted polysaccharides were evaluated on the basis of their ability to bind with bile acids. Additionally, mice were fed a high-fat diet to induce hyperlipidemia and then administered the extracted polysaccharides via oral gavage for 4 weeks. The optimal conditions for the ultrasound-assisted enzymatic extraction process were an enzyme mass fraction of 2.5% (neutral protease: xylanase: cellulase=1:1:1), an extraction temperature of 48 ℃, and an extraction time of 123 min. Under these conditions, the polysaccharide yield was 36.62% and the mass fraction was 87.20%. The binding rates of the extracted polysaccharides with cholic, deoxycholic, taurocholic, and glycocholic acids were 86.56%, 89.47%, 84.26%, and 64.68%, respectively. Compared with the hyperlipidemic mice, the mice treated with 200 or 400 mg/kg of the extracted polysaccharides exhibited significant decreases in body weight (11.29% and 15.38%, respectively), fat indices (4.07% and 3.18%), serum triglyceride levels (59.87% and 68.42%), total cholesterol (28.24% and 39.08%), and low-density lipoprotein-cholesterol (34.93% and 49.28%), as well as significant increases in high-density lipoprotein-cholesterol levels (52.67% and 99.00%). In conclusion, the optimized conditions for the ultrasound-assisted enzymatic extraction of polysaccharides from algal residue of C. lentillifera were reasonable and reliable, and the extracted polysaccharides showed good bile acid binding abilities in vitro as well as hyperlipidemia-ameliorating effects in model mice fed a high-fat diet.

海南省自然科学基金高层次人才项目（322RC590）；国家自然科学基金青年基金项目（31902418）；海南省自然科学基金面上项目（821MS027）