Rheum, Scutellaria, and Houttuynia effervescent tablets: a green strategy for controlling Vibrio parahaemolyticus outbreaks in aquaculture

ObjectiveThe widespread misuse of antibiotics in aquaculture has led to severe drug resistance, threatening both industry sustainability and food safety. With increasing restrictions on antibiotic use, plant-derived antimicrobials have emerged as eco-friendly alternatives. This study aims to optimize the formulation of herbal effervescent tablets incorporating extracts from Rheum officinale, Scutellaria baicalensis, and Houttuynia cordata, followed by evaluation of their antimicrobial efficacy against Vibrio parahaemolyticus (V. parahaemolyticus).MethodsThe tablet formulation was optimized using a Box-Behnken design (BBD) and evaluated through composite performance scoring. Antibacterial efficacy was determined by monitoring V. parahaemolyticus growth (Optical Density value in 600 nm, OD600), measuring minimal inhibitory concentration (MIC)/minimal bactericidal concentration (MBC) values, assessing mutant prevention concentration (MPC) using high-density inoculum (1010 colony-forming units (CFU)/mL), analyzing the mutant selection window (MSW), and performing time-kill kinetic studies.ResultsThe optimized effervescent tablets (0.5 g) contained 16.20% Rheum officinale, 9.75% Scutellaria baicalensis, and 4.05% Houttuynia cordata extracts, with excipients ensuring rapid disintegration (30 ± 1.2s), stable pH (6.34 ± 0.15), and sterility. Antibacterial testing showed strong efficacy against V. parahaemolyticus, with MIC/MBC of 32/64 mg/mL and MPC of 38.4 mg/mL (MSW: 32–38.4 mg/mL). Time-kill kinetics demonstrated concentration-dependent bactericidal effects (>3-log CFU reduction in 6 h at ≥2×MIC).ConclusionBox-Behnken design effectively optimized herbal effervescent tablets with superior pharmaceutical performance and potent bactericidal effects against V. parahaemolyticus. The narrow mutant selection window (MSW) indicates potentially low resistance risk, highlighting their promise as a potential green strategy that warrants further in vivo investigation.