Abstract:
This study aims to investigate the antioxidant and hypoglycemic potentials of sweet potato(
Ipomoea batatas L.)leaves by comparing antioxidant activity and
α-glucosidase inhibitory activity of sweet potato leaf extracts from 7 varieties. The content of total polyphenols and flavonoids in sweet potato leaves was measured. The antioxidant activity(DPPH· scavenging ability,ABTS
+· scavenging ability,·OH scavenging and reducing ability)and
α-glucosidase inhibitory activity were evaluated by
in vitro experiments. The results showed that there were significant differences in the content of total polyphenols and flavonoids,antioxidant activity and
α-glucosidase inhibitory activity among sweet potato leaf extracts from 7 varieties. The content of total polyphenols in sweet potato leaves ranged from 15.02 to 33.33 mg GAE/g DW,and the content of total flavonoids from 1.06 to 3.11 mg RE/g DW. The content of total polyphenols and flavonoids was the highest in sweet potato leaves of Xushu 18,Jishu 18 and Longshu 9,without statistical differences(
P>0.05). Free radical scavenging ability(DPPH·,ABTS
+·,·OH)was the highest in Longshu 9. The reducing ability was the highest in Jishu 18. Shangshu 19 presented the highest
α-glucosidase inhibitory activity. The content of total polyphenols and flavonoids showed an extremely positive correlation with antioxidant activity(
P<0.01),but no obvious correlation with
α-glucosidase inhibitory activity(
P>0.05). This study demonstrates that sweet potato leaves are a good source of potential antioxidants and
α-glucosidasee inhibitors,providing a theoretical basis for sweet potato cultivation and the selection of sweet potato varieties.