The Thai medicinal plant Gynura pseudochina var. hispida: chemical composition and in vitro NF-Kappa B inhibitory activity

Gynura pseudochina (L.) var. hispida Thv. (Asteraceae) has been used in traditional medicine in Thailand for the treatment of conditions associated with chronic and acute inflammation. In continuation of our search for bioactive natural products from Thai medicinal plants, G. pseudochina var. hispida showed potential in vitro NF-kappaB (Nuclear Factor kappa B) inhibitory activity and, therefore, was chosen for bio-assay-guided isolation of active compounds. Bioassay-guided fractionation of the methanol extract of the leaves of G. pseudochina var. hispida led to the isolation and identification, by spectroscopic and mass spectrometric methods, of four compounds previously not reported from this poorly studied species: Quercetin 3- rutinoside (1), 3,5-di-caffeoylquinic acid (2), 4,5-di-caffeoylquinic acid (3), and 5-monocaffeoylquinic acid (4). This paper discusses the current knowledge of these active components as NF-kappaB inhibitors, which lends some support to the use of this plant in traditional medicine. Potential risks associated with pyrrolizidine alkaloids will, however, have to be investigated further.