Impact of Valerian (Valeriana officinalis) Extract Supplementation on Common Carp (Cyprinus carpio L.) Growth Performance, Immune Responses, and Gene Expression

This study evaluated the effects of dietary supplementation with valerian (Valeriana officinalis) extract on growth performance, immune responses, and gene expression in common carp (Cyprinus carpio). Four experimental diets (V-0, V-0.25, V-0.5, and V-1) containing 0%, 0.25%, 0.5%, and 1% valerian extract were administered for 30 days. Dietary supplementation did not significantly influence growth performance (p > 0.05). Glutathione peroxidase (GPX) activity remained unchanged except in the high-dose group (V-1), while malondialdehyde (MDA) activity was significantly reduced in the V-0.25 group (p < 0.05). Aspartate aminotransferase (AST) activity increased in the V-1 group (p < 0.05), whereas alanine aminotransferase (ALT) activity decreased in the V-0.25 group (p < 0.05). Albumin (ALB) levels were elevated in the V-1 group (p < 0.05), while globulin (GLB) levels increased in all valerian-supplemented groups (p < 0.05). Creatinine (CRT) levels rose significantly only in the V-1 group (p < 0.05), and cholesterol levels decreased in the 0.5% and 1% groups (p < 0.05). Gene expression analysis revealed an increase in interleukin-1 beta (IL-1β) expression in the V-0.5 group (p < 0.05) but reductions in IL-10 and heat shock protein 70 (HSP70) in the V-0.25 group (p < 0.05). Superoxide dismutase (SOD) and catalase (CAT) gene expression levels significantly decreased in the groups fed with 0.25% and 0.5% valerian extract (p < 0.05), while catalase (CAT) gene expression levels significantly decreased in the groups fed with 0.25% and 0.5% valerian extract (p < 0.05). GPX gene expression levels declined across all experimental groups (p < 0.05). Tumor necrosis factor alpha (TNF-α) gene expression showed no significant changes (p > 0.05). These findings highlight the potential of valerian extract as a functional feed additive. However, further research with extended feeding durations and varying doses is required to understand its physiological effects in aquaculture better.