Antioxidant Potential and Phytochemical Profile of Althaea (Hatmi) and Hibiscus Flower Extracts: A Comprehensive Analysis

In this study, the bioactive components and antioxidant properties of Althaea (Hatmi) and Hibiscus plants were assessed using various methods. Both aqueous and ethanol extracts of these plants yielded distinct and effective results. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and Ferric Reducing Antioxidant Power (FRAP) assays at concentrations of 25, 50, 75, and 100 mg/mL. Hatmi extracts, both ethanol and aqueous, exhibited high DPPH activity, particularly at 75 and 100 mg/mL, while Hibiscus showed a linear increase in DPPH activity with concentration, reaching 2000 µM Trolox Equivalent (TE) /g dry weight (DW) at 100 mg/mL. In ABTS assays, lower concentrations of ethanol extracts were more effective, but higher aqueous concentrations showed greater activity. FRAP results indicated high antioxidant activity in Hatmi ethanol extracts, with activity reaching 2700 µM TE/g DW at higher concentrations. Phenolic analysis revealed high levels of apigenin 7-glucoside, hesperidin, and caffeic acid in Hatmi, while Hibiscus extracts contained significant amounts of chlorogenic acid and quercetin. Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that Hatmi had a higher abundance of volatile organic compounds compared to Hibiscus.