Study on extraction process and antioxidant activity of total flavonoids from Dendrobium officinale leaves

HUANG Qiong; XIE Xiangji

doi:10.13557/j.cnki.issn1002-2813.2025.15.015

Abstract：The study aimed to optimize the ultrasonic extraction process for total flavonoids from Dendrobium officinale leaves and investigate their antioxidant activity.The extraction process was optimized using a response surface methodology.The scavenging rates of the total flavonoids against 1,1-diphenyl-2-trinitrophenylhydrazine(DPPH)radicals,2,2-biazo-di(3-ethylbenzothiazole-6-sulfonic acid)diammonium salt(ABTS)radicals,and hydroxyl radicals were measured.Additionally,the total flavonoid content in Dendrobium officinale at different growth stages and plant parts,as well as the antioxidant activity of mature Dendrobium officinale from different parts,were determined.The results showed that the optimal ultrasonic extraction parameters were ultrasonic power of 300 W,extraction time of 20 min,ethanol concentration of 60％,liquid-to-material ratio of 35 mL/g,extraction temperature of 60 ℃,and two times of extraction.Under these conditions,the highest yield of total flavonoids from the leaves reached 2.91％.Mature Dendrobium officinale leaves exhibited the highest total flavonoid content of 2.91％,while seedling Dendrobium officinale stems showed the lowest total flavonoid content of 1.01％.The IC50 values of total flavonoids from Dendrobium officinale leaves on DPPH radicals,ABTS radicals,and hydroxyl radicals scavenging capacity were 0.39,0.43,and 0.36 g/L,respectively.The scavenging ability of mature Dendrobium officinale leaves to ABTS radicals and hydroxyl radicals was stronger than that of mature stems and flowers,while the scavenging ability of mature Dendrobium officinale flowers to DPPH radicals was stronger than that of mature leaves and stems.The study indicates that total flavonoids from Dendrobium officinale leaves and flowers hold potential as natural antioxidant feed additives.