Purpose:
To develop a simple and rapid method for extracting total flavonoids from the roots of
Flemingia philippinensis
and to investigate the antioxidant and anti-tumor activities of the extracts of the
materials from various locations in China.
Methods:
The total flavonoids in
F. philippinensis were obtained by ultrasonic-assisted conventional
solvent extraction method, and the extraction conditions were optimized by single factor and orthogonal
test. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and anti-tumor activities, using 3-(4,5-
dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, of the extract were evaluated. The
contents of flemiphilippinin A, auriculasin, 5,7,3',4'-tetrahydroxy-6,8 –diprenylisoflavone and dorsmanins
I were also determined.
Results:
Optimal extraction conditions were as follows: extraction time, 40 min; methanol concentration,
85%; and solvent to solid ratio, 40 mL/g; and number of extraction, once. Total flavonoid content varied
greatly (3.7 - 14.35%) among the 19 samples collected from different origins in China. Flemiphilippin A,
5,7,3',4'- tetrahydroxy-6,8 -diprenylisoflavone, auriculasin and dorsmanins I showed varying DPPH
radical scavenging activities with effective half maximal concentration (EC
50) of 18.36, 23.59, 57.25 and
63.54 μg/mL, respectively. Flemiphilippinin A (5 μg/mL) also exhibited some level of antitumor activity
against human hepatocellular carcinoma cell (BEL-7402), human lung epithelial (A-549) and human
ileocecal adenocarcinoma cell (HCT-8) with inhibition of 91.13 ± 1.6, 91.22 ± 3.23, and 79.77 ± 3.57 %,
respectively.
Conclusion:
Total flavonoids can be extracted efficiently from
F. philippinensis by ultrasonic-assisted
extraction method. Flemiphilippinin A has a potential for use in medicine as an antioxidant and antitumor
drug.
