Phytochemical analysis of Stachys iva: Discovering the optimal extract conditions and its bioactive compounds

The Lamiaceae family is one of the widest plant families among Greek flora, consisting of a great variety of species, with the genus Stachys being one of its largest representatives, spread to most continents. The genus Stachys is also known for its beneficial properties and has been used for years as a traditional remedy for healing various health conditions. Stachys iva, an endemic plant in the Kozani Regional unit, has also been consumed as an infusion by locals and is reported to relieve common cold symptoms, have antimicrobial properties, and contribute to normalizing blood glucose levels. The present study aimed to identify the chemical compounds (such as phenolic acids, flavonoids, and phenylethanoid glycosides) responsible for the herb's pharmacological properties and determine the optimal extraction conditions to gather an extract with high therapeutic value without solvent and energy waste. Experiments conducted proved that extracting by simple stirring with deionized water for 75 min at 80°C is the best option. In contrast, the extract's total polyphenol content was determined, and the compounds were identified by high-performance liquid chromatography analysis. In addition, other methods were utilized (e.g., ferric-reducing antioxidant power assay and 2,2-diphenyl-1-picrylhydrazyl antiradical activity assay) to reveal potent antioxidant, anti-hydrogen peroxide, and anti-inflammatory activity, while the correlation between these properties and extraction conditions was also examined.