Antioxidant activity and phenolic–flavonoid content of Phlomis pungens var. pungens collected in Erzincan (Türkiye)

Objective: In this study, the antioxidant capacity of the methanol:water (7:3, v/v) extract obtained from the aerial parts of Phlomis pungens var. pungens (PP), native to Erzincan province, Turkey, was evaluated. Methods: The antioxidant activity of the herbal extract was investigated by different spectrophotometric methods; 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical scavenging tests, ferric reducing antioxidant power (FRAP), total phenolic content (TPC) and total flavonoid content (TFC) analyses were carried out. Results: According to the obtained data, the DPPH• and ABTS•+ free radical scavenging capacity of the PP extract was determined to be low compared to synthetic antioxidants (DPPHIC50: 99.02 µg/mL, ABTS IC50: 36.04 µg/mL). The 82.45 mg TE/g extract value obtained as a result of the ferric reducing antioxidant power (FRAP) analysis indicates that the reducing capacity of PP is moderate. Total phenolic content was measured as 49.23 mg GAE/g extract, and total flavonoid content was measured as 24.57 mg QE/g extract. These values indicate that the extract has a certain level of antioxidant potential. Conclusion: The findings suggest that PP may be considered a potential natural antioxidant source due to its phenolic and flavonoid compounds, although its activity was observed to be moderate. Furthermore, when compared with the limited number of studies in literature, the results are generally consistent; however, some differences were observed due to factors such as the extraction methods used, solvent ratios, and the environmental conditions in which the plant was collected. Overall, this study contributes valuable data to the current understanding of the biological potential of PP and supplements the limited existing literature on this species.