Te Urewera Propolis Profile Reflects Local Flora Over Poplar Type

New Zealand researchers have determined that propolis produced by honeybees within the Te Urewera indigenous forest, or ngahere, possesses a distinct chemical signature that sets it apart from conventional European varieties. This significant finding challenges the long-held assumption that New Zealand's propolis is primarily of the "poplar type," which is typically characterized by high flavonoid content derived from poplar resins. The discovery highlights the unique ecological niche of the region and the specific interactions between local bees and the native flora.

A detailed study conducted in the Ruatāhuna region has established a direct link between the chemical profile of the local native vegetation and the final product manufactured by the bees. Initial assessments revealed that this propolis, sourced from indigenous flora, is heavily saturated with diterpenoids rather than the flavonoids that dominate resins collected from poplar trees. Specifically, scientists identified several key diterpenoids within this endemic propolis, including:

• Isocupressic acid
• Acetylisocupressic acid
• Manool
• Torulosal
• Communic acid
• Ferruginol

These identifications were rigorously confirmed using advanced analytical techniques, specifically gas chromatography-mass spectrometry (GC-MS) and NMR spectroscopy. Interestingly, this specific chemical makeup shares more similarities with Mediterranean-type propolis and certain samples found in Brazil than with its European counterparts. The geographic isolation of New Zealand has allowed its unique native flora to evolve independently over the 250 years since the beginning of European colonization.

A collaborative research effort involving the Tuawhenua Trust and the University of Waikato is currently underway to fully characterize these unique chemical components during the present nectar collection season. Experts from the University of Waikato’s School of Science, including researchers reachable at manleyha@waikato.ac.nz, are actively engaged in completing this comprehensive profiling to better understand the regional variations. Propolis is a complex resinous substance that bees gather from tree buds and modify with their own enzymes; it is known to contain more than 800 biologically active compounds.

While traditional propolis is often valued for its flavonoid-rich antibacterial properties, the diterpenoid-heavy New Zealand samples have demonstrated remarkable antioxidant behavior. Laboratory testing showed a high antioxidant potential, recording a TEAC value of 1481 mg of Trolox per gram. Furthermore, the substance exhibited dose-dependent inhibition of mitochondrial dehydrogenase and suppressed superoxide production with an IC50 value of 262 µg/mL, indicating a high level of biological activity.

Beyond its antioxidant capacity, the research also documented a potent inhibitory effect against both methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) Staphylococcus aureus. These medicinal properties are largely attributed to the presence of the identified diterpenoids, highlighting the immense therapeutic potential of this regional New Zealand product. This study not only redefines the chemical understanding of local propolis but also opens new avenues for the pharmaceutical and wellness industries to utilize these unique native compounds found in the heart of Te Urewera.