Potential activities for constituents from Vicia faba L.

A survey of phytochemical and biological investigation of Vicia faba L. flowers resulted in isolation of polyphenolic and nitrogenous compounds; kaempferol-3- O-α-D-galactopyranosyl 7-O-α-L rhamnopyranoside 1, kaempferol-3-O-(3"-O-α-Lrhamnopyranosyl)-α-L-rhamnopyranoside 2, kaempferol-3-O-α-L-rhamnopyranosyl (1→6)-β-D-galactopyranoside-7-O-α-L-rhamnopyranoside 3, allantoin 4 and adenosine 5. For 1-3, it is the first report of their isolation from V. faba L. The structure of the isolated compounds has been characterized on the basis of spectroscopic methods in addition to comparison with literature data. These compounds along with methanol extract were tested to evaluate their antioxidant activity estimated by oxygen radical absorption capacity (ORAC) assay and anti-allergic activities through inhibition of β-hexosaminidase enzyme. For the antioxidant activity, both methanolic extract and the isolated compounds exhibited a high activity ranged from 3.1-9.6 mg TE/ mg extract. For the antiallergic activity, it was noticed that all the tested compounds and methanol extract have good inhibition for β-hexosaminidase release without affecting the cell viability where the production of β-hexosaminidase was decreased to about 69- 82%. These results revealed that the methanol extract and its isolated compounds of V. faba L. flowers had high antioxidant and high anti-allergic activities. It is expected that V. faba L. flowers could be used for the treatment of oxidative stress and will find new and high-value-added uses in cosmetics.