Effects of geographical location and environmental factors on metabolite content and immune activity of Echinacea purpurea in China based on metabolomics analysis

Echinacea purpurea (L.) Moench, a well-known “immunostimulant” in the West, is one of the most popular plants. The quality and activity of plants are often affected by the environment in that they grow, such as geographical location, climate, and soil. This study reports levels of primary and secondary metabolites and immunomodulatory activity in different parts of E. purpurea from the main regions in which these species are cultivated in China. Metabonomics results showed that E. purpurea in different regions were separated into multiple clusters. Furthermore, the contents of 8 metabolites in E. purpurea differed among regions and parts and differences in immune signaling in macrophages were also observed, including IL-1β, IL-6, TNF-α, and NO. Correlation analyses and redundancy analyses revealed that these differences of E. purpurea were related to geographical location (latitude and longitude) and environmental variables (climate and soil). Precipitation and soil pH were important factors affecting the difference in metabolite contents and immune activity of E. purpurea . The most critical reason for the high immune activity of E. purpurea in Hunan may be due to the high precipitation and slightly acidic pH. The results showed that the metabonomics approach is a powerful strategy for assessing the quality of medicinal plants . Meanwhile, our study was of great significance in site selection and rational cultivation of E. purpurea . • Identification of metabolites in E. purpurea using NMR metabolomic. • Environmental factors had significant effects on the composition of E. purpurea. • High AP and slightly acidic pH may benefit E. purpurea quality. • AP affects E. purpurea quality by affecting chlorogenic acid, choline, 3,5-o-dicaffeoylquinic acid, and coumaric acid levels. • pH affects E. purpurea quality by regulating chicoric acid, acetate, choline, and 1,3-o-dicaffeoylquinic acid levels.