Fig. 9.

The graphical illustration of the inhibitory effects of KH in a PMACI-induced mast cell activation. Apart from the IgE-mediated mast cell activation, a mast cell can be stimulated to release allergic-related inflammatory mediators, such as histamine, β-hexosaminidase, IL-4, IL-6, IL-8, and TNF-α by the use of PMACI. An increase in intracellular calcium level due to PMACI causes activation of the signalling pathways associated with mast cell stimulation. The present study demonstrated that polyphenols from stingless bee honey were able to inhibit the activation of mast cells by interacting with some of the signalling molecules such as MAPKs (p38α, ERK, and JNK), NF-κB, Calmodulin-1, and PKC alpha. In particular, the interaction of the polyphenols with MAPKs is stronger than the other 3 signalling molecules (denoted by a larger inhibition sign)