Combination of white tea and peppermint demonstrated synergistic antibacterial and anti-inflammatory activities

BACKGROUND White tea, considered to be the oldest form of tea, is becoming a popular beverage for its organoleptic characteristics. Peppermint tea, used as a herbal remedy for centuries, is now also very popular throughout the world as herbal tea. What interested us was that in ancient China, peppermint was used in combination with tea as a detoxification or anti-inflammatory agent. However, there are few reports on the combined use of white tea and peppermint. Therefore, this study aims to investigate the antibacterial and anti-inflammatory activities of white tea in combination with peppermint. RESULTS A synergistic inhibitory effect against four bacterial strains, especially against Staphylococcus argenteus, was observed in the combination of white tea and peppermint in vitro. In addition, the combined formula demonstrated a stronger anti-inflammatory effect in vivo than either of the two used alone, which was associated with the decrease of the pro-inflammatory cytokines of interleukin-6 (IL-6), interleukin-1beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). In a further mechanism study, it was found that white tea and peppermint inhibited the phosphorylation of p-I kappa B-alpha and mitogen-activated protein kinase (MAPK) at different degrees. While the enhanced anti-inflammatory effect of the combined formula was associated with the combination of NF-kappa B down-regulation and p-MAPK inhibition. CONCLUSION In our study, it was for the first time shown that when white tea was combined with peppermint, the antibacterial and anti-inflammatory effects were enhanced. The results suggested an effective application of white tea in combination with peppermint as a potential antibacterial and anti-inflammatory functional food. (c) 2020 Society of Chemical Industry

Automated summary

White tea and peppermint combination showed a synergistic inhibitory effect against bacterial strains and a stronger anti-inflammatory effect compared to individual use in both in vitro and in vivo studies. The enhanced anti-inflammatory effect was attributed to the down-regulation of pro-inflammatory cytokines and the inhibition of NF-kappa B and p-MAPK phosphorylation. The study suggests the potential application of white tea and peppermint as a functional food with antibacterial and anti-inflammatory properties.