Anatomical Specialization of Myristica fragrans Houtt. Extracts: Targeted Antimicrobial Efficacy Against Veterinary Cutaneous Pathogens

บทคัดย่อ

The escalating global crisis of antimicrobial resistance (AMR) in veterinary practice necessitates the urgent development of sustainable, plant-derived topical agents for managing cutaneous infections. This study systematically evaluated the antimicrobial potency of 75% ethanol extracts from three distinct anatomical fractions of nutmeg (Myristica fragrans Houtt.); the pericarp, seed coat (mace), and kernel; against major veterinary pathogens, including Pseudomonas aeruginosa, Staphylococcus aureus, S. epidermidis, and Streptococcus pyogenes. Using the agar well diffusion method, the extracts demonstrated significant anatomical specialization in their inhibitory profiles. The pericarp extract exhibited the broadest antimicrobial spectrum at 500 mg/mL, with inhibition zones reaching up to 29.40 ± 1.31 mm; however, its activity was attenuated at lower concentrations (≤125 mg/mL). In contrast, the kernel extract demonstrated remarkable inhibition efficacy, maintaining potent inhibitory zones (14.70–17.30 mm) against S. aureus, S. epidermidis, and S. pyogenes even at the lowest concentration of 125 mg/mL, suggesting the presence of highly active, dilution-stable compounds. Thin-layer chromatography profiling revealed that each fraction possesses distinct phytochemical fingerprints, correlating with their varying biological activities. These findings substantiate the necessity of targeted extraction strategies over whole-fruit processing to optimize therapeutic yield. Consequently, nutmeg-derived kernel and pericarp fractions represent promising natural candidates for integration into veterinary dermatological formulations to mitigate infection and address the AMR challenge.