METHODS: The present study examined the inhibitory effects of all collected honey on the release of selected inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-4, IL-6, IL-8, histamine, and β-hexosaminidase in an activated HMC. Besides that, all honey's total phenolic content (TPC) was also examined, followed by using liquid chromatography with tandem mass spectrometry (LC-MS/MS) to identify the phytochemicals in the honey. Further examination of the identified phytochemicals on their potential interaction with selected signaling molecules in an activated mast cell was conducted using computational methods.
RESULTS: The results indicated that there were significant inhibitory effects on all selected inflammatory mediators' release by KH sourced from bamboo (BH) and rubber tree (RH) at 0.5% and 1%, but not KH sourced from mango (AH) and noni (EH). BH and RH were found to have higher TPC values and were rich in their phytochemical profiles based on the LC-MS/MS results. Computational studies were employed to determine the possible molecular target of KH through molecular docking using HADDOCK and PRODIGY web servers.
CONCLUSIONS: In short, the results indicated that KH possesses anti-allergic effects towards an activated HMC, possibly by targeting downstream MAPKs. However, their anti-allergic effects may vary according to their botanical sources. Nevertheless, the present study has provided insight into the potential application of stingless bee honey as a complementary and alternative medicine to treat various allergic diseases.
AIM OF THE STUDY: As allergy could be mediated by both IgE and IgG, we further evaluated the anti-allergy potential of CNAE in both in vitro model of IgG-induced macrophage activation and in vivo anaphylaxis models to further dissect the mechanism of action underlying the anti-allergic properties of CNAE.
MATERIAL & METHODS: The anti-allergy potential of CNAE was evaluated in in vivo anaphylaxis models of ovalbumin-challenged active systemic anaphylaxis (OVA-ASA) and IgE-challenged passive systemic anaphylaxis (PSA) using Sprague Dawley rats as well as IgG-challenged passive systemic anaphylaxis (IgG-PSA) using C57BL/6 mice. Meanwhile, in vitro model of IgG-induced macrophage activation model was performed using IC-21 macrophages. The release of soluble mediators from both IgE and IgG-mediated pathways were measured using enzyme-linked immunosorbent assay (ELISA). The signaling molecules targeted by CNAE were identified by performing Western blot.
RESULTS: IgG, platelet-activating factor (PAF) and IL-6 was suppressed by CNAE in OVA-ASA, but not IgE. In addition, CNAE significantly suppressed PAF and IL-6 in IgG-PSA but did not suppress histamine, IL-4 and leukotrienes C4 (LTC4) in IgE-PSA. CNAE also inhibited IL-6 and TNF-α by inhibiting the phosphorylation of ERK1/2 in the IgG-induced macrophage activation model.
CONCLUSION: Overall, our findings supported that CNAE exerts its anti-allergic properties by suppressing the IgG pathway and its mediators by inhibiting ERK1/2 phosphorylation, thus providing scientific evidence supporting its traditional use in managing allergy.