Preliminary Screening for Various Bioactivities in Honey and Propolis Extracts from Thai Bees

Aims: Honey and propolis have long been used in traditional medicine whilst honey is consumed as food. A screening for various bioactivities in honey from Apis florea and A. andreniformis, and the crude water and ethanol extracts of propolis from A. mellifera and Tetragonula laeviceps, from Thailand are reported.
Study Design: Cell based study.
Place and Duration of Study: Department of Biology, Faculty of Science, Chulalongkorn University, between June 2010 and April 2011.
Methodology: Various components such as protein, sugar, gluconic acid were assayed in honey while total sugar, reducing sugar, total polyphenol and flavonoid content were assayed in crude propolis. Samples were tested for in vitro antimicrobial, in vitro antiplasmodial and antiproliferative activities.
Results: The crude propolis extracts showed good bioactivities. Antibacterial activity was found against Bacillus cereus (a model Gram-positive bacteria) in the water extracts of propolis from T. laeviceps (TLW) and A. mellifera (AMW), with MIC values of 50 and 100 µg/ml, respectively, whilst against Escherichia coli (a model Gram-negative bacteria), TLE revealed some 24.0% growth inhibition. Most interestingly, the ethanol extract of propolis from T. laeviceps (TLE) displayed a strong anti-malarial activity with a MIC of 4.48 µg/ml against in vitro Plasmodium falciparum growth, whilst AMW revealed a high inhibition of Mycobacterium tuberculosis growth (74.3%). Furthermore, TLW (50 µg/ml) provided the highest anti-Herpes Simplex Virus type 1 replication activity at 33.0% without any sign of cytotoxicity to the host Vero cells. Finally, in vitro anti-proliferation activity against four cancer cell lines in tissue culture was noted with IC50 vales ranging between 25.5 - 29.3 and 26.8 – 49.5 µg/ml for TLE and AME, respectively.
Conclusion: Overall, the propolis of Thai A. mellifera and T. laeviceps exhibit diverse and some novel bioactivities worthy of further enrichment and characterization.