Correlation analysis of Antimicrobial, Antioxidant, and Anti-Inflammatory Activities of Two-Spotted Cricket (Gryllus bimaculatus) Oil: Implications for Veterinary and Cosmeceutical Use

Purpose: In a previous study, two-spotted cricket oil (GBO) was characterized for terms of its fatty acid composition and its antioxidant and anti-inflammatory activities, while its antimicrobial activity remained unexamined. This study aimed to evaluate the antimicrobial activity of GBO against five animal pathogenic bacteria and to investigate the correlations among the antimicrobial, antioxidant, and anti-inflammatory activities of GBO. Methods: The antimicrobial activity of GBO was evaluated against five animal pathogens (<i>Aeromonas salmonicida</i> subsp. salmonicida, <i>Staphylococcus aureus, Salmonella</i> Typhimurium, <i>Lactococcus garvieae</i>, and <i>Vibrio anguillarum</i>) using the broth dilution method. Spearman correlation analysis was performed between the pathogen growth inhibition data and previously reported antioxidant, anti-inflammatory, and cell viability data for GBO. Results: GBO exhibited minimum inhibitory concentrations (MICs) ranging from 3.125% to 6.25% (v/v) against the five animal pathogenic bacteria, well below its previously established cytotoxic threshold. Bacterial growth was strongly negatively correlated with total flavonoid content (TFC) and DPPH radical scavenging activity, and strongly positively correlated with nitric oxide (NO) production. Conclusion: GBO exhibited broad-spectrum antimicrobial activity against all five pathogens tested and Spearman correlation analysis showed that this activity varied in a coordinated manner with its flavonoid-driven antioxidant capacity and suppression of NO production. These findings suggest an interconnected, rather than independent, basis for its antimicrobial, antioxidant, and anti-inflammatory properties and support its potential as a functional ingredient in veterinary cosmeceutical formulations for companion and aquatic animals.