Evaluation of Galantamine, Phenolics, Flavonoids and Antioxidant Content of Galanthus Species in Turkey

Aims: The aim of the present study was to determine the total phenolic and flavonoid content and antioxidant activities in Galanthus species (Gaalanthus woronowii, Galanthus nivalis, and Galanthus elwesii) indigenous to Turkey.

Study Design: The plant materials used in the study, Galanthus elwesii samples were collected in Antalya province, Galanthus nivalis samples were collected in Istanbul province, and Galanthus woronowii samples were collected in Çaykara, Trabzon province in September 2018.

Place and Duration of Study: Plant samples were stored in Herbarium Material Warehouse at Afyon Kocatepe University. The plant leaves and grated bulbs were dried in an incubator at 60°C. The bulb and leaf samples were then pulverized to 80 mesh particle size for analysis.

Methodology: Total phenolic content was determined spectrophotometrically with Folin-Ciocalteu procedure and calculated as gallic acid equivalent (GAE). Total flavonoid content was determined with aluminum chloride colorimetric method and calculated as catechin equivalent (CAE). Antioxidant activities were determined with TEAC (Trolox equivalent antioxidant capacity) and DPPH (diphenyl-p-picrylhydrazyl radical) methods. The phenolic acid and galantamine content were determined by reversed phase HPLC.

Results: The highest total flovanoid content was determined as 33 mg CAE/g DW in Galanthus woronowii leaves and as 27 mg CAE / g DW in bulbs. DPPH removal activity was 77% in 500 μg/mL Galanthus woronowii leaf extract concentration and 93% in the ascorbic acid control group. The highest antioxidant content was observed in the leaves of Galanthus woronowii as 23 µmol Trolox/100 g DW and as 21 µmolTrolox/100 g DW in the bulbs. Higher galantamine content was determined in aerial parts (leaves) when compared to the underground parts (bulbs). The galantamine content in the leaves of all three Galanthus species was about 0.082%. The galantamine content in the bulbs of all three species was about 0.045%. Gallic, protocatechic, vanilic, caffeic, syringic, rosmarinic acid and catechin were identified in the leaves and bulbs of the three species with HPLC phenolic acid analysisIt was determined that the major phenolic acid was gallic acid.

Conclusion: The present study findings demonstrated that Galantthus species has antioxidant capacity. Galanthus spp. leaves had higher antioxidant activity when compared to the bulbs. Galanthus woronowii exhibited the highest antioxidant activity among the scrutinized species.