Functional roles of ginger (Zingiber officinale) in strengthening the physiological responses, growth, antioxidant/immune gene expression, and resistance to Fusarium oxysporum in Red Tilapia (Oreochromis sp.): in vivo and in silico approaches

The integration of natural molecules into aquaculture promotes sustainability by leveraging the fish's immune system to optimize health, productivity, and pathogen resistance. Ginger is widely utilized as an immunomodulatory herb, its impact on the health and productivity of red tilapia (Oreochromis niloticus x O. mossambicus) has yet to be fully elucidated. Hence, this study sought to determine how dietary dried ginger powder (DGP) influences red tilapia by examining the growth performance, feed efficiency, body composition, blood chemistry, liver and intestinal health, gene expression (antioxidant and immune-related), and resistance to Fusarium oxysporum challenge. In a 56-day feeding trial, 180 red tilapia were assigned to a basal diet supplemented with 0 (DGP0), 5 (DGP5), 10 (DGP10), or 15 (DGP15) g/kg of dried ginger powder (DGP), followed by a Fusarium oxysporum challenge. Dietary DGP significantly improved growth indices and feed consumption while lowering the feed conversion ratio (FCR) compared to the control group (p < 0.05). Fish receiving 5 and 10 g/kg DGP exhibited reduced lipid content and lower liver enzyme activities (ALT, AST, and ALP), whereas all DGP inclusion levels significantly increased ash and moisture content (p < 0.005). DGP10 and DGP15 groups showed significantly higher protein content (p < 0.05) relative to other groups. Immune parameters (lysozyme and phagocytic activities) and antioxidant enzymes (SOD and CAT) were significantly enhanced by DGP supplementation, with the most pronounced effects observed at the 15 g/kg inclusion level (p < 0.05). Dietary DGP supplementation preserved the structural integrity of hepatopancreatic and intestinal tissues. These histological improvements were supported by a significant, dose-dependent upregulation of pro-inflammatory cytokines (IL1β, IL8) and chemokines (CC chemokine), alongside antioxidant enzymes (SOD, CAT, and GPx), particularly at the 15 g/kg inclusion level (p < 0.05). DGP-fortified diets significantly enhanced resistance against F. oxysporum, as evidenced by higher post-challenge survival rates. Molecular docking indicated that the eight ginger-derived compounds were assessed for their inhibitory potential against chitin synthase enzyme (Chs3) in F. oxysporum, through molecular docking. Among them, 10-Shogaol exhibited the highest binding affinity at -8.2 kcal/mol. Overall, DGP particularly at 10 or 15 g/kg, proved highly effective in enhancing red tilapia growth, blood health, and disease resistance. In vivo, DGP inclusion at 10 and 15 g/kg optimized growth indices and physiological health, providing robust protection against pathogenic challenge. Driven by its robust antioxidant and immunomodulatory properties, DGP represents a sustainable nutritional strategy for enhancing the performance and disease resistance of red tilapia.