Dietary Myo-Inositol Improves Growth, Antioxidant and Immune Responses in Bisphenol S-Exposed Procambarus clarkii

Bisphenol S (BPS) is an emerging environmental contaminant that can disrupt oxidative and immune homeostasis in aquatic organisms, whereas myo-inositol (MI) is a water-soluble nutrient involved in growth and cellular signaling. This study evaluated growth, hepatopancreatic biochemical indices, and stress-related gene transcription in crayfish fed 0 or 1000 mg/kg supplemental MI and chronically exposed to 0-10 µg/L BPS for 6 weeks. Compared with the control group, the BPS group had significantly lower weight gain rate (WGR), specific growth rate (SGR), molting frequency, antioxidant enzyme activities (SOD, CAT, and POD), and immune enzyme activities (ACP, AKP, PO, and LZM), together with higher MDA content (P < 0.05). Compared with the BPS group, the MI + BPS group had significantly higher WGR, SGR, molting frequency, SOD, POD, ACP, and PO activities (P < 0.05). The MI + BPS group also showed higher nrf2 and hmc mRNA levels and lower keap1, bip, ire1, casp3, cytc, jnk, il-6, tnf-α, and nf-κb mRNA levels than the BPS group (P < 0.05). WGR, SGR, molting frequency, and hmc mRNA abundance in the MI + BPS group did not differ significantly from the control group (P > 0.05), the remaining endpoints showed indicator-specific responses. These findings indicate that dietary MI supplementation was associated with improved growth and selected antioxidant and immune indices, as well as altered transcription of genes related to oxidative, endoplasmic-reticulum-stress, inflammatory, and apoptosis-associated responses under BPS exposure. Pathway activation, tissue injury, and apoptosis were not directly assessed.