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

Abstract

BackgroundThe 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.PurposeThis 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.MethodsThe tablet formulation was optimized using a Box-Behnken design and evaluated through composite performance scoring. Antibacterial efficacy was determined by monitoring Vibrio parahaemolyticus growth (OD600), measuring MIC/MBC values, assessing mutant prevention concentration (MPC) using high-density inoculum (1010CFU/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±1.2 s), stable pH (6.34±0.15), and sterility. Antibacterial testing showed strong efficacy against V. parahaemolyticus, with MIC/MBC of 16/32 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 (BBD) effectively optimized herbal effervescent tablets with superior pharmaceutical performance and potent bactericidal effects against V. parahaemolyticus. The narrow mutant selection window (MSW) indicates low resistance risk, highlighting their promise as a natural aquaculture treatment.