Antioxidant, anti-inflammatory and anti-acne activities of stingless bee (Tetragonula biroi) propolis

We collected stingless bee propolis Tetragonula biroi in order to find materials for medicine and cosmetics applications from tropical rainforest resources. Even though this bee has some biological functions including a cancer cell line, hair growth promotion, asthma remedy, α-glucosidase enzyme inhibition, and antiviral action, the investigation on anti-acne has not been reported yet. This study was to focus on propolis Tetragonula biroi extracts and leads us to isolate active compounds for antioxidant, anti-inflammatory, and anti-acne. We used methanol to obtain the extract from this propolis and assayed it with antioxidants, anti-inflammation, and anti-acne. The extract showed strong activity in antioxidants by DPPH radical scavenging activity (82.31% in 6.25 μg/ml). Via a column chromatography and Reveleris PREP purification system, we isolated 3’–O–methyldiplacone, nymphaeol A, and 5,7,3′,4′–tetrahydroxy–6–geranyl flavonol. These compounds showed potential biological activity with IC₅₀ for antioxidant 6.33, 15.49, 17.32 μM; and antiinflammatory 121.54, 121.20, 117.31 μM. The isolated compounds showed anti-acne properties with properties 0.00, 14.11, and 13.78 mm for the inhibition zone (at a concentration of 1 μg/well), respectively. The results indicated that the propolis extract of Tetragonula biroi has the potential to be developed as a cosmetic agent; however, further work needs to be done to clarify its application.