COMPARATIVE CHEMICAL AND BIOLOGICAL ACTIVITY OF SELECTIVE HERBAL EXTRACTS
Ioana Humulescu
Abstract
The imbalance of oxidative processes poses a serious threat by overproduction of free radicals and various reactive species. Therefore, polyphenol and flavonoid-rich medicinal plants represent a common trend in daily use and pharmaceutical research. Our study focused on two type of extracts that isolated flavonoid derivatives, polyphenolic acids, and iridoids from three Teucrium species endemic in Romania. The chemical evaluation by spectrophotometric and ultra-high-performance liquid chromatography techniques indicated that methanol was a better solvent than methanol/dichloromethane mixture for quercetin, luteolin, and apigenin derivatives. Caffeic acid, rosmarinic acid, and harpagide were also identified. The biological activity was assessed by antioxidant assays (2, 2-diphenyl-1-picrylhydrazyl radical scavenger, lipoxygenase, and cholinesterase's inhibition). All in all, the methanolic extracts exhibited the best antiradical and enzyme inhibitory activity, the intensity was correlated to the chemical composition. Also, T. polium followed by T. chamaedris proved to be the richest in compounds with good antioxidant activity and represent the best choices for further investigation.