Abstract

The nutritional profile of bee pollen varies based on botanical and geographical origin. The study was conducted to compare the bioactive compounds and free radical scavenging activity of methanol extract of pollen based on botanical origin. The botanical origin was identified using the harmonized method of melissopalynology. Phenol, flavonoid, and free radical scavenging activity were done by standard method. Five major plants namely Bidens spp., Guizotia scabra, Croton macrostychus, Eucalyptus camaldulensis and Zea mays were identified. The results indicated that pollen released from Bidens spp. exhibited minimum total phenolic contents (TPC; 27.5 ± 0.8 mg GAE (Gallic acid equivalent) 100 g-1) and total flavonoid content (TFC; 18.8 ± 0.7 mg (QE (Quercetin equivalent) 100 g-1) while E. camaldulensis recorded maximum TPC (62.4 ± 0.5 mg GAE 100 g-1) and TFC (59.6 ± 0.2 mg QE 100 g-1). Based on the EC50 values, the current finding showed antioxidant activity with IC50 values ranging from 0.036 ± 0.005 (E. camaldulensis) to 0.233 ± 0.057 (Bidens spp.) mg mL-1, which were lower than that of the positive ascorbic acid control (IC50, 0.023 ± 0.005 mg mL-1). Ethiopian bee pollen could be considered a nutritional addition to food to prevent diseases related to free radicals.

Keywords: Antioxidant activity, Flavonoid, Melissopalynological analysis, Phenol, Pollen