Antioxidant Properties of Galium Verum

The genus Galium (Rubiaceae), comprised of approximately 1300 species and used for the treatment of a variety of pathological conditions in folk medicine of many cultures. In this study, antioxidant activities of aerial parts of G. verum were investigated employing various in vitro assay systems, i.e. DPPH and nitric oxide radical scavenging, reducing power and H2O2 scavenging. IC50 for DPPH radical-scavenging activity was 59.6 ± 0.04 μg ml . The extract exhibited potent reducing power at 50 800 μg ml that were comparable with Vitamin C. Also, extract showed very strong nitric oxide-scavenging. IC50 was 1.7 ± 0.01 μg ml. Extract was capable of scavenging hydrogen peroxide in a concentration dependent manner. It showed very strong activity. At 50 μg ml, percentage of inhibition was 92.5 %. The extract exhibited very potent antioxidant activities in all tested models. The total amount of phenolic compounds in extract was determined as gallic acid equivalents (753 ± 21 mg g of extract) and total flavonoid contents were calculated as quercetin equivalents (151.25 ± 8.2 mg g of extract) from a calibration curve. This plant was a good source of phenols and contains very high amount of total flavonoids and phenolic compounds. The very potent antioxidant activity may be attributed to the presence of phenols and flavonoids in the extract.