Lotus stamen has antioxidant properties. - GreenMedInfo Summary
Antioxidant principles of Nelumbo nucifera stamens.
Arch Pharm Res. 2003 Apr;26(4):279-85. PMID: 12735685
Faculty of Food Science and Biotechnology, Pukyong National University, Busan 608-737, Korea.
In our ongoing study to identity antioxidants from natural sources, the antioxidant activity of Nelumbo nucifera stamens was evaluated for their potential to scavenge stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, inhibit total reactive oxygen species (ROS) generation, in kidney homogenatas using 2',7'-dichlorodihydrofluorescein diacetate (DCHF-DA), and scavenge authentic peroxynitrites (ONOO-). A methanol (MeOH) extract of the stamens of N. nucifera showed strong antioxidant activity in the ONOO- system, and marginal activity in the DPPH and total ROS systems, so were therefore fractionated with several organic solvents, such as dichloromethane (CH2Cl2), ethyl acetate (EtOAc) and n-butanol (n-BuOH). The EtOAc soluble fraction, which exhibited strong antioxidant activity in all the model systems tested, was further purified by repeated silica gel and Sephadex LH-20 column chromatographies. Seven known flavonoids [kaempferol (1), kaempferol 3-O-beta-D-glucuronopyranosyl methylester (2), kaempferol 3-O-beta-D-glucopyranoside (3), kaempferol 3-O-beta-D-galactopyranoside (4), myricetin 3',5'-dimethylether 3-O-beta-D-glucopyranoside (5), kaempferol 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (6) and kaempferol 3-O-beta-D-glucuronopyranoside (7)], along with beta-sitosterol glucopyranoside (8), were isolated. Compound 1 possessed good activities in all the model systems tested. Compounds 2 and 7 showed scavenging activities in the DPPH and ONOO- tests, while compounds 3 and 4 were only active in the ONOO- test. Conversely, compound 8 showed no activities in any of the model systems tested.