Comparative In-Vitro Efficacy of Chenopodium quinoa Seed and Eriobotrya japonica Fruit Extracts Against Methicillin-Resistant Staphylococcus aureus (MRSA)

The rise of antimicrobial resistance, particularly Methicillin-resistant Staphylococcus aureus (MRSA), necessitates the exploration of novel therapeutic agents from accessible and affordable sources. This study provides a direct comparative evaluation of the in-vitro antimicrobial efficacy of methanolic extracts from commercially available Chenopodium quinoa seeds and Eriobotrya japonica fruit against a clinical MRSA isolate. Plant materials were purchased from a local supermarket. Extracts were prepared using Soxhlet extraction with 100% methanol. The antimicrobial activity was assessed by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) using the broth microdilution method according to CLSI guidelines. Data were analyzed using independent samples t-tests. The E. japonica fruit extract demonstrated significantly stronger anti-MRSA activity than the C. quinoa seed extract. The mean MIC and MBC for E. japonica fruit were 126.0 ± 2.8 µg/mL and 251.0 ± 2.4 µg/mL, respectively. In contrast, C. quinoa seeds exhibited a mean MIC of 501.6 ± 5.3 µg/mL and an MBC of 1005.0 ± 10.0 µg/mL. The differences were statistically significant (p < 0.0001), with the E. japonica fruit extract being approximately 4-fold more potent. The antimicrobial effects were dose-dependent. The methanolic fruit extract of Eriobotrya japonica, a commercially available product, is a potent source of bactericidal compounds against MRSA and shows significantly greater promise than Chenopodium quinoa seeds for the development of new phytotherapeutic agents to combat antibiotic-resistant infections. The accessibility and affordability of loquat fruit make it particularly attractive for large-scale development