Guaijaverin and Epigallocatechin Gallate Complex Modulate Th1 and Th2 Cytokine-Mediated Allergic Responses Through STAT1/T-bet and STAT6/GATA3 Pathways.

We aimed to determine the in vitro and in vivo synergistic antiallergic effect of guaijaverin and epigallocatechin gallate (EGCG) complex (GEC), and the antiallergic rhinitis (AR) properties of guaijaverin-rich Psidium guajava and EGCG-rich Camellia sinensis (ILS-F-2301). GEC showed synergistic inhibition of β-hexosaminidase by 4.20% and interleukin (IL)-4, -5, and -13 by 4.08%, 0.67%, and 4.71%, respectively, while increasing interferon (IFN)-γ by 12.43%, compared with EGCG only. In addition, 50 μg/mL of ILS-F-2301 inhibited β-hexosaminidase release, and inhibited IL-4, -5, and -13 by 61.54%, 58.79%, and 59.25%, respectively, while increasing IFN-γ (showing 133.14% activation). Moreover, 50 μg/mL of ILS-F-2301 suppressed p-STAT6 and GATA3, while p-STAT1 and T-bet increased, and 0.039 μg/mL of guaijaverin or 5.275 μg/mL of EGCG modulated T helper (Th)1- and Th2-related proteins. These data suggested that guaijaverin and EGCG in ILS-F-2301 was the main active compound involved in Th1/Th2 modulation. In the AR mouse model, the administration of ILS-F-2301 inhibited ovalbumin (OVA)-specific IgE, histamine in serum; it also inhibited IL-4 and -5 by 28.23% and 47.15%, respectively, while increasing IFN-γ (showing 37.11% activation), compared with OVA/Alu-treated mice. Taken together, our findings suggest that ILS-F-2301 is a functional food for alleviating anti-AR.