Biologically Active Compounds and Antioxidant and DNA-Protective Potential of Rhodope Avens (Geum rhodopaeum...

This article is the first report highlighting Rhodope avens as a natural source of bioactive compounds with potential pharmaceutical applications. Dry tinctures obtained from herba (HDT) and rhizoma (RDT) from the Balkan Peninsula endemic plant Geum rhodopaeum were analyzed and tested for antioxidant activity (DPPH, ABTS, FRAP, CUPRAC assays) and DNA nicking protection potential. The tinctures were characterized by a high total polyphenol content (total the polyphenols in RDT were more than twice that of HDT, i.e., 516.6 mg GAE/g dt; p < 0.01). HPLC analysis revealed the presence of 14 phenolics, with the main one being (over 3 mg/g dt) (+)-catechin (28.21 mg/g dt for RDT; 9.67 mg/g dt HDT), followed by protocatechuic acid, salicylic acid, and rutin. Rosmarinic acid content is herein first reported for the genus Geum. GC/MS analysis identified 41 compounds, among which monosaccharides predominated (with the highest fructose content), followed by gluconic acid, glucose-1-phosphate, mannitol, sorbitol, and glycerol in HDT, along with xylitol in RDT. The tinctures exhibited strong antioxidant potential as evaluated by the methods used, with the most pronounced effect found in the CUPRAC assay (5 458.87 μM TE/g dt for HDT; 10 073.99 μM TE/g dt for RDT; p < 0.01), as confirmed in comparison to proven antioxidants such as BHT and vitamin C. DNA-protective activity against oxidative damage was established and microscopic identification of the herbal substances was also performed.