Antioxidant, Anticholinesterase, Antiproliferative Activities and Phenolic Content of Geranium tuberosum

In this study, antioxidant, anticholinesterase, antiproliferative activities and phenolic compound contents of Geranium tuberosum L. were investigated. Plant samples were collected from Sivas (Turkey) and extracts were prepared by ethanol extraction. Antioxidant capacities were determined by total antioxidant capacity (TAS), total oxidant level (TOS), oxidative stress index (OSI), DPPH radical scavenging and FRAP methods. Anticholinesterase activity was tested using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes according to the Ellman method, with galantamine used as a positive control. Antiproliferative effects were investigated in the A549 lung adenocarcinoma cell line by MTT method at concentrations of 25, 50, 100 and 200 µg/mL. Phenolic contents were determined by LC-MS/MS analysis. TAS, TOS, and OSI values of G. tuberosum were found to be 3.257 ± 0.138 mmol/L, 10.335 ± 0.139 µmol/L, and 0.318 ± 0.012, respectively. DPPH and FRAP values were measured as 114.304±3.642 and 159.957 ± 1.978 mg TE/g, respectively. In anticholinesterase assays, AChE was 145.027 ± 3.847 µg/mL, and BChE was 202.030 ± 2.350 µg/mL, which were higher than the values of the positive control galantamine. In antiproliferative assays, cell viability was found to decrease depending on concentration, with the strongest cytotoxic effect observed at 200 µg/mL. In the phenolic analysis, the highest compound was gallic acid (15253.09 ± 4.36 mg/kg), followed by quercetin (6393.49 ± 3.74 mg/kg) and kaempferol (3292.65 ± 1.91 mg/kg). Protocatechuic acid, caffeic acid, catechin hydrate, luteolin, and syringic acid were also determined. The results revealed that G. tuberosum is rich in phenolic compounds, exhibits strong antioxidant properties, provides significant inhibition of cholinesterase enzymes, and exhibits a dose-dependent antiproliferative effect against cancer cells. These findings suggest that the species is a valuable natural resource from a pharmacological perspective and may be evaluated in phytotherapeutic and functional food formulations in the future.