Total phenolic content, total flavonoid and antioxidant activity of ethanolic bee pollen extracts from three species of Malaysian stingless bee

Bee pollen consists of flower pollen mixed with bee digestive enzymes and preserved with some honey and nectar. It contains high antioxidant activity due to the presence of polyphenols and flavonoids. This study was aimed at investigating the chemical profiles of bee pollen extracts from three species of Malaysian stingless bee, Trigona (Tetrigona) apicalis, Trigona (Heterotrigona) itama and Trigona (Geniotrigona) thoracica. Chemical profiles analyzed were total phenolic content (TPC), total flavonoid content (TFC) and antioxidant assay. T. apicalis showed the highest TPC value (135.93 +/- 0.02 mg GAE/g) followed by T. thoracica (103.62 +/- 0.04 mg GAE/g) and T. itama (33.46 +/- 0.02 mg GAE/g). The concentration of flavonoids in this study showed that T. thoracica had the highest TFC (31.80 +/- 0.13 mg QE/g), followed by T. apicalis (25.72 +/- 0.17 mg QE/g) and T. itama (15.28 +/- 0.04 mg QE/g). In antioxidant measurement, T. thoracica gave higher percentage of DPPH inhibition with the EC50 was 0.86 +/- 0.01 mg/ml. This was followed by T. apicalis at concentration of 1.05 +/- 0.01 mg/ml and T. itama at 3.24 +/- 0.03 mg/ml. In conclusion, bee pollen extract from T. thoracica showed the highest TFC and DPPH inhibition whereas T. apicalis showed the highest TPC value. Due to the diversity and complexity of the bee pollen, further investigations should be performed to further evaluate the chemical profiles of polyphenolic composition, which may be important for its health promoting effects.