Antibacterial Activity, Antioxidant Capacity and Immune Gene Modulation of Six Medicinal Plants in CHSE-214 Cells

This study evaluated the therapeutic potential of 70% ethanol extracts from six medicinal plants (<i>Chenopodium album</i>, <i>Cassia tora</i>, <i>Cudrania tricuspidata</i>, <i>Dioscorea polystachya</i>, <i>Lonicera japonica</i>, <i>Solidago virgaurea</i> subsp. <i>gigantea</i>) through their antibacterial, antioxidant, cytotoxic, and immunomodulatory activities, targeting applications in aquaculture. All extracts exhibited potent antibacterial activity (MIC ≤ 10 μg/mL) against <i>Aeromonas</i> spp. and <i>Photobacterium damselae</i> subsp. <i>damselae</i>, but limited efficacy against <i>Streptococcus parauberis</i>. <i>C. tricuspidata</i> (CTR) and <i>C. tora</i> (CTO) demonstrated superior antioxidant activity (IC₅₀ = 1292 μg/mL and IC₅₀ = 227 μg/mL, respectively), correlating with high polyphenol content (1498 and 1409 mg GAE/g). CTR displayed significant concentration-dependent cytotoxicity (IC₅₀ = 904.2 μg/mL), while <i>C. album</i> (CA) promoted cell proliferation (132.3% viability). In LPS-stimulated CHSE-214 cells, <i>D. polystachya</i> (DP) induced the highest <i>IL-8</i> expression (207-fold), followed by <i>Chenopodium album</i> (CA) (194-fold <i>IL-8</i>, 49-fold <i>TNF-α</i>) and CTR (245-fold <i>RIPK2</i>), activating NF-κB, MAPK, and NOD-like receptor pathways critical for teleost immunity. <i>Lonicera japonica</i> (LJ) suppressed <i>TNF-α</i> (0.4-fold) and <i>IRF1</i> (0.3-fold), indicating anti-inflammatory potential, while <i>S. virgaurea</i> subsp. <i>gigantea</i> (SV) showed biphasic <i>TNF-α</i> modulation (79-fold at 10 μg/mL, 5-fold at 100 μg/mL). These diverse bioactivities, particularly the robust immunomodulatory effects, highlight the promise of these extracts as natural therapeutic agents for fish health management in aquaculture.