Chemical constituents isolated from Polygala japonica leaves and their inhibitory effect on nitric oxide production in vitro

Abstract

A methanolic extract of dried leaves of Polygala japonica Houtt (Polygalaceae) significantly attenuated nitric oxide production in lipopolysaccharide-simulated BV2 microglia. Five anthraquinones chrysophanol (1), emodin (2), aloe-emodin (3), emodin 8-O-β-D-glucopyranoside (4) and trihydroxy anthraquinone (5), and four flavonoids kaempferol (6), chrysoeriol (7), kaempferol 3-gentiobioside (8) and isorhamnetin (9) were isolated from the methanolic extract using bioactivity-guided fractionation. Among them, compounds 1–4, 6 and 7 showed significant inhibitory effect on lipopolysaccharide-induced nitric oxide production in BV2 microglia at the concentrations ranging from 1.0 to 100.0 μM.

Keywords::

• Polygala japonica
• lipopolysaccharide
• BV2 microglia
• nitric oxide
• inhibition

Acknowledgements

This research was supported by a grant PF06200-00 from Plant Diversity Research Center of the 21st Century Frontier Research Program funded by the Ministry of Science and Technology, Korea.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.