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.