Correlation of the immunostimulatory activities of honeys with their contents of identified bioactives

- All New Zealand and non-New Zealand honeys are capable of inducing TNF-α release from blood monocytes, except for amber honey.
- The different honeys differed greatly in their immunostimulatory activity.
- Arabinogalactan proteins (AGPs) and apisimin are commonly present in both New Zealand and non-New Zealand honeys at different concentrations.
- The levels of apisimin and AGPs levels did not correlate exactly with the immunostimulatory activity of a particular honey type.

Honeys with unique compositions and properties are worth studying for their health-promoting effects. In order to correlate bioactive content with immunostimulatory activity we compared the abilities of seventy eight New Zealand and non-New Zealand honeys to stimulate blood monocytes to release tumour necrosis factor (TNF)-α, and examined the compositions of selected honeys that had widely varying activities. All the honeys, except for a Malaysian “Amber honey” stimulated the release of TNF-α from monocytes. However, the honeys differed greatly in their immunostimulatory activity, even within the same honey type. They differed in their contents of immunostimulatory components, including apalbumins, arabinogalactan proteins, and apisimin, whose levels did not correlate exactly with immunostimulatory activities. We suggest that the immunostimulatory properties of honey may be influenced by other factors, including unidentified immunostimulatory bioactives and immunosuppressive components; the bioavailability of some bioactives may depend on unidentified factors.