Melittin (MLT, Forapin, Forapine) is an activator of phospholipase A2 (PLA2) that stimulates the activity of the low molecular weight PLA2, while it does not the increase the activity of the high molecular weight enzyme.
In vitro studies using TNF-α/IFN-γ-stimulated human keratinocytes shows that melittin inhibits the increased expression of chemokines, such as CCL17 and CCL22, and pro-inflammatory cytokines, including IL-1β, IL-6 and IFN-γ, through the blockade of the NF‐κB and STAT signalling pathways.[2]
Melittin exhibits potent anti-atopic activities, shown by decreased Atopic dermatitis (AD)-like skin lesions, induced by DNCB in mice.[2]
[1] M R Steiner, et al. Biochim Biophys Acta. 1993 Feb 10;1166(1):124-30. [2] Hyun-Jin An, et al. Br J Pharmacol. 2018 Dec;175(23):4310-4324.