Mechanism of action of Houttuynia cordata extract and its application in animal production

The global phasing-out of antibiotic growth promoters (AGPs) has catalyzed an urgent search for efficacious and sustainable alternatives to maintain livestock health and productivity. Houttuynia cordata Thunb . (HC), a traditional pharmacophagous herb has emerged, as a promising candidate due to its pleiotropic bioactive profile. This review outlines the molecular mechanisms and clinical efficacy of HC extracts (HCE) as multifunctional feed additives. We elucidate that HCE, rich in volatile oils, flavonoids, and polysaccharides, systemically modulates host physiology by activating the Nrf2/HO-1 antioxidant signaling axis while concurrently suppressing hyper-inflammation via the inhibition of TLR4/NF-κB and NLRP3 inflammasome pathways. Crucially, HCE reinforces epithelial integrity across various biological barriers (intestinal and mammary) through the upregulation of tight junction proteins. Across diverse production systems, HCE has significant efficacy under experimental conditions. In ruminants, it alleviates heat stress-induced redox imbalance and mitigates mastitis. In monogastric species, it enhances viral resistance (notably against PRRSV) and optimizes meat quality. In aquaculture, it fortifies non-specific mucosal immunity against viral challenges. Despite technical hurdles regarding component stability and standardized quality control, HCE represents a transformative, green nutritional strategy. Advancements in microencapsulation and nano-emulsification are poised to catalyze the industrial integration of HCE, positioning it as a cornerstone of sustainable animal agriculture in the post-antibiotic era.