Abstract
Purpose: To
optimize extraction of total
triterpene acids from loquat leaf and evaluate their in
vitro antioxidant activities.
Methods:
The independent variables
were ethanol concentration, extraction time, and solvent
ratio, while the dependent variable was content of total
triterpene acids. Composite design and response surface
method were used to optimize the extraction process,
while antioxidant activity was evaluated in vitro using
α,α-diphenyl-β-picrylhydrazyl (DPPH) and pyrogallol
autoxidation methods.
Results:
The optimum extraction
conditions were as follows: 81 % ethanol, extraction
time 160 min, and extraction cycles 2, ratio of solvent
to sample 14mL/g. Under these conditions, the yield of
total triterpene acids reached 3.41 %. Furthermore,
total triterpene acids exhibited strong reducing power,
as well as radical scavenging activity against DPPH (IC50,
203.41 mg/L) and superoxide anion free radical; when the
concentration was > 274.64 mg/L, scavenging ability
increased significantly.
Conclusion:
Total triterpene acids from
loquat leaf possess an antioxidant activity in vitro,
but further studies are required to develop them into
effective drugs and health foods for human applications.
Keywords:
Eriobotrya
japonica (Thunb.) Lindl.,, Triterpene acids, Extraction
optimization, Response surface methodology, Antioxidant
