Prenylated Flavonoids as Antioxidant and Melanin Inhibitors From Stingless Bee (Wallacetrigona incisa) Propolis

Abstract

Propolis from 4 stingless bees ( Homotrigona apicalis, Wallacetrigona incisa, Tetragonula fuscobalteata, and Tetragonula fuscibasis) was investigated in the search for medicinal and cosmetic materials from tropical rainforest resources. Methanol extracts of the propolis were screened using antioxidant and antimelanogenesis assays (tyrosinase enzyme activity and melanin inhibitor in B16 melanoma). The extract of H. apicalis showed the strongest antioxidant activity, both in the 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays, with half-maximal inhibitory concentration values of 0.72 ± 0.01 (mg/mL) and 0.26 ± 0.00 (mg/mL), respectively. The H. apicalis extract also displayed the strongest inhibition of tyrosinase (53% at 100 µg/mL). In the B16 melanoma cell assay, the W. incisa extract showed the strongest inhibition of melanin (21%) and was less cytotoxic. The W. incisa extract was fractioned to isolate the compounds with biological activities. Two prenylated flavonoids were obtained, named broussoflavonol F and glyasperin A. Both showed potent antioxidant activities, as well as inhibiting melanin in B16 melanoma, but not tyrosinase activity. These results indicated the potential of methanol extract of W. incisa to be developed for cosmetic material, but further experiments are needed to verify the function.

Extracts from European Propolises as Potent Tyrosinase Inhibitors

“…Tested extracts at a concentration of 100 µg/mL showed the inhibition of tyrosinase at a range of 14-53%. The highest inhibitory activity was shown for the extract of propolis produced by the species Wallacetrigona incisa, rich in two prenylated flavonoids: broussoflavonol F and glyasperin A [2]. In another work, among 21 samples of propolis collected in different locations in Morocco, two of them exhibited potent inhibitory activity towards tyrosinase, with IC 50 values of 0.050 and 0.037 mg/mL [7].…”

“…Samples rich in flavonoid compounds showed inhibition in the range of 40.14-56.66%, and propolis samples of mixed composition inhibited tyrosinase by 37.24-47.25% [5]. In another study, propolis extracts from the samples acquired from four stingless bee species (Homotrigona apicalis, Wallacetrigona incisa, Tetragonula fuscobaleata, and Tetragonula fuscibasis) were screened for melanogenesis regulatory activity [2]. Tested extracts at a concentration of 100 µg/mL showed the inhibition of tyrosinase at a range of 14-53%.…”

“…After 15 min of incubation at room temperature in darkness, the absorbance of the samples was measured at λ = 405 nm using a microplate reader. The percentage of radical scavenging in both assays was calculated for each sample based on the following equation: % of radical scavenging = [1 − (Abs(S)/Abs(C))] × 100 (2) where Abs(S)-the corrected absorbance of the extract and Abs(C)-the corrected absorbance of the control sample (radical + solvent).…”

“…Propolis, also known as bee glue, is a resinous material, due to its physical properties, used by bees in the hive mainly as a sealing and building material to strengthen the edges of the combs and the entrance to the hive. Bees coat the cavities, damages, and gaps in the walls of the hive with propolis [1,2]. Chemically, propolis is a mixture of plant resin (60%), wax (30%), and volatiles (10%), completed with 5% of other organic compounds [3].…”

Evaluating the Application Potential of a Recombinant Ganoderma Protein as Bioactive Ingredients in Cosmetics

“…Melanin, a pigment commonly found in animals, plants and humans, is prominent in the skin, mucosa, retina, and ovaries. Melanin is synthesized by specialized pigment-producing cells known as melanocytes through a series of enzymatic and spontaneous reactions related to tyrosine conversion [ 5 ], accompanied by the production of reactive oxygen species (ROS) and reactive oxidants [ 6 ]. Melanosomes within melanocytes enable the synthesis of melanin that was transferred to the surrounding keratinocytes, providing the basic tone of human skin [ 7 ].…”