Variation in phenolic profiles and antioxidant properties among medicinal and culinary herbs of the Lamiaceae family

Abstract

Lamiaceae herbs are known for their ability to produce high concentrations of phenolic compounds and other antioxidants. In this study, the phenolic content and antioxidant properties of twenty-three Lamiaceae plants spanning ten different genera—including well known and less common cultivars—were determined and phenolic compounds were identified within these herbs. Phenolic production in plants is highly dependent on various environmental factors, so herbs were grown under identical conditions to minimize differences in chemical composition due to agronomic practices. Results showed statistical differences in the total phenolic contents, ferric reducing ability of plasma (FRAP) reducing capacities, and DPPH (2,2-diphenyl-1-picrylhydrazyl) antioxidant capacities among these culinary and medicinal herbs. Genus also significantly influenced phenolic concentrations and antioxidant properties. Thirteen phenolic compounds were identified within the plants including hydroxycinnamates, hydroxybenzoates, flavonoid glycosides, and tuberonic acid glucoside (a jasmonate). Hierarchical cluster analysis placed herbs in the Monarda genus in a single group that was characterized by high phenolic levels and strong antioxidant properties. Monarda plants are valued in traditional medicine based upon their healing properties, and our results suggest that these herbs are important candidates for further investigation.