Amber Extract Suppressed Mast Cell-Mediated Allergic Inflammation via the Regulation of Allergic Mediators—An In Vitro Study

The various clinical approaches for treating allergy-related diseases have shown modest progress in low side effects and improved clinical outcomes. Therefore, finding alternative anti-allergic agents is crucial. The present study explored the anti-allergic effects of amber extract (fossilized tree resin) in RBL-2H3 mast cells stimulated with different allergens. In order to support the information on the inflammatory effect of the amber extract, NO production analysis on RAW 264.7 cells was conducted. β-Hexosaminidase release, an indicator of the efficacy of the amber extract in preventing mast cell activation and degranulation, reactive oxygen species (ROS) generation, and the effect of the amber extract on key cytokines production on RBL-2H3 cells, was evaluated. The results demonstrated that amber extract at concentrations up to 50 μg/mL had no cytotoxic effect on RAW 264.7 and RBL-2H3 cells. Amber extract inhibited NO production in RAW 264.7 cells. Treatment with amber extract significantly suppressed the release of β-hexosaminidase, especially at 50 μg/mL. Furthermore, amber extract suppressed the significantly increased ROS levels induced by allergen stimulation and allergy-associated cytokines. The results also suggested that amber extract exerts anti-allergic inflammatory effects by inhibiting the MAPK and NF-κB signaling pathways, resulting in decreased cytokines production. Thus, the amber extract is a promising anti-allergic agent.