Evaluation of Antioxidant Activity, Phenolic, and Flavonoid Content of Tussilago farfara L. in Different Altitudes and Phenological Stages

Tussilago farfara L. is a perennial forb belonging to the Asteraceae family. The leaves and flowers of this plant have medicinal properties, and its essential oil has been used for the treatment of dry coughs and inflammation of the mouth, throat, and respiratory tract. This study aimed to assess some phytochemical characteristics of Tussilago farfara L. and compare changes in this plant at different altitudes.

To investigate the changes in the amount of the effective substance of the studied plant in the altitude gradient, altitude classes of 1100-2600 meters were considered in Golestan province, Iran, considering the presence and abundance of the species. In each phenological stage (before and after flowering time), plant samples were randomly collected in each altitude class and transferred to the laboratory. Total phenol content and flavonoid content were measured using the Folin-Ciocalteu and aluminum chloride methods, respectively. The antioxidant activity of the methanolic extract was also evaluated using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) reagent.

The results showed that the highest amounts of total phenol content, flavonoids, and antioxidant activity were observed at altitudes above 2200 meters, and there was a significant difference in plants (Tussilago farfara L.) grown in different altitudes in terms of phytochemical properties. Based on the comparison of phytochemical properties of this plant in different phenological stages, the highest content of total phenol and flavonoids were observed in the phonological stage of flowering and the highest (42.08%) antioxidant activity of leaves was observed in the vegetative stage.

The results of this study can help activists in the field of medicinal plants to determine the appropriate height range and phenological stage in harvesting the leaves of this plant to achieve the highest levels of phenol content, flavonoids, and antioxidant activity.