Effects of Lactic Acid Bacteria Fermentation on the Active Components, Antioxidant Activity and Enzymes on Hypoglycemic Activity in Vitro of Acanthopanax senticosus Leaves

In order to provide a theoretical basis for the application of Acanthopanax senticosus leaves in probiotic fermented health products, the Acanthopanax senticosus leaves were used as raw materials, and the three kinds of lactic acid bacteria were used for fermentation, namely Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum. After that，the changes in the content of bioactive compounds in Acanthopanax senticosus leaves fermented by lactic acid bacteria were studied, and the effect on antioxidant and inhibitory activity of hypoglycemic related enzymes in vitro were evaluated. The results showed that the fermentation abilities of the 3 strains were different. The fermentation of Lactobacillus plantarum and Lactobacillus acidophilus significantly increased the content of total flavonoids in Acanthopanax senticosus leaves (P<0.05), 2.02 times and 1.45 times higher than that in the control group. The content of polysaccharides, saponins and isoperidine in Acanthopanax senticosus leaves were significantly increased by fermentation of three strains of lactic acid bacteria (P<0.05), and the polysaccharide content of Lactobacillus casei fermentation group was the highest, reaching 12.7 mg/g. The saponin content of Lactobacillus plantarum fermentation group was the highest, which was 1.9 times as high as that of the control. The content of isoperidine in Lactobacillus casei fermentation group was the highest, which was 3.2 times higher than that in control group. In vitro functional evaluation experiments showed that the fermentation by 3 lactic acid bacteria improved DPPH free radical scavenging ability, hydroxyl free radical scavenging ability, superoxide anion free radical scavenging ability, and α-amylase and α-glucosidase inhibition ability of Acanthopanax senticosus leaves, which increased with the increase of the concentration of fermentation products. To sum up, the fermentation of Acanthopanax senticosus leaves by lactic acid bacteria could enrich the bioactive compounds, enhance the ability of antioxidant and inhibition of hypoglycemic related enzymes, which could be used as an important way for processing functional food from Acanthopanax senticosus leaves.