Evaluating Biological Properties of Stingless Bee Propolis

• Published in: Foods
• Main Authors: Jin Ru Lim, Lee Suan Chua, Dawood Ali Salim Dawood
• Format: Article
• Language: English
• Published: MDPI AG 2023-06-01
• Subjects: chemical composition; maceration; stingless bee propolis; ultrasonic pretreatment; antioxidant; antibacterial activity
• Online Access: https://www.mdpi.com/2304-8158/12/12/2290

The aim of the present study was to determine the content of phenolics, flavonoids and tannins, as well as the biological functions of propolis extracts from the stingless bee (<i>Heterotrigona itama</i>). The raw propolis was extracted via maceration with ultrasonic pretreatment in 100% water and 20% ethanol. The yield of ethanolic propolis extracts was about 1% higher than its aqueous counterpart. The colorimetric assays showed that the ethanolic propolis extract had about two times higher phenolics (17.043 mg GAE/g) and tannins (5.411 mg GAE/g), and four times higher flavonoids (0.83 mg QE/g). The higher phenolic content had enhanced the antiradical and antibacterial capacities of the ethanolic extract. The propolis extracts significantly exhibited higher antibacterial activity against gram-positive bacteria (<i>Staphylococcus aureus</i>) than gram-negative bacteria (<i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>). However, aqueous extract was found to have a higher anticancer property based on the viability of lung cancer cells. No cytotoxic effect was observed on normal lung cells as the cell viability was maintained >50%, even the concentration of propolis extracts were increased up to 800 µg/mL. Different chemical compositions of propolis extract would show different bioactivities depending upon the individual applications. The high content of phenolics suggests that the propolis extract could be a natural source of bioactive ingredients for the development of innovative and functional foods.