Sodium houttuynia alleviates airway inflammation in asthmatic mice by regulating FoxP3/RORγT expression and reversing Treg/Th17 cell imbalance

•Sodium houttuynia (SH) effectively ameliorates the Treg/Th17 cell imbalance in vivo.•SH reduces the airway inflammation, hyperresponsiveness, and mucus hypersecretion.•It increases the frequency of CD4+CD25+FoxP3+ Treg cells and the secretion of IL-10.•It decreases the proportion of Th17 cells and IL-17A production.•Hence, SH may represent a therapeutic compound for asthma.