Isoorientin is a common C-glycosyl flavone in the human diet. It has been isolated from several plant species, including Phyllostachys pubescens, Crataegus monogyna and Crataegus pentagyna, Patrinia villosa Juss, Drosophyllum lusitanicum, buckwheat, Arum palaestinum, and Rumex and Swertia. Isoorientin possesses significant anti-nociceptive and anti-inflammatory activities. Significantly protected PC12 nerve cells from 6-OHDA-induced apoptotic neurotoxicity and reduced the proliferation of HepG2 cells. Isoorientin showed anti-RSV (respiratory syncytial virus) activity.