Abstract
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 (EC50) 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.
Highlights
Flemingia philippinensis Merr. et Rolfe, which belongs to the plant family Leguminosae, is mainly distributed in tropical areas of China
The total flavonoid content in 19 samples were determined by calibration curve of genistein (Y = 0.1726X-0.0756 with r2=0.9996) and repeated three times for each under the optimal conditions
The extracts of 19 samples exhibited DPPH radical scavenging activities in the range 12.20 ± 1.41 % to 42.69 ± 1.07 % at concentration of 25 μg dry matter/mL, which suggested that the activities remarkably consisted with the content of their total flavonoids extracted under the optimal condition
Summary
Flemingia philippinensis Merr. et Rolfe, which belongs to the plant family Leguminosae, is mainly distributed in tropical areas of China. To the best of our knowledge, there are no reports on total flavonoids content to evaluate the quality of the herb F. philippinensis and explore the antitumor activity. Nineteen samples (numbered 1 - 19) of F. philippinensis were collected from different locations in China, mainly in Guangxi Province, in the spring of 2009 They were identified by Professor Xiaojun Ma, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College. The effect of sonication time (A), methanol concentration (B), solvent volume (C) and extraction times (D) on the yield of total flavonoids were investigated. Methanol solution of DPPH 2 mL of 0.2 mM radicals was incubated with a series of different concentrations of the extract or flavonoids. Statistical analysis was performed using Graphpad prism 5.0 and data analyzed using one way analysis of variance (ANOVA) for comparison between groups followed by Dunnett's multiple comparison test at a significant level of p < 0.05
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
