Uji Aktivitas Antibakteri Kombinasi Ekstrak Etanol Daun Miana (Coleus atropurpureus L.) dan Daun Jambu Biji (Psidium guajava L.) terhadap Pertumbuhan Bakteri Escherichia coli

Masayu Syarmila Putri Abas (Universitas Negeri Gorontalo)
La Ode Aman (Universitas Negeri Gorontalo)
Multiani S. Latif (Universitas Negeri Gorontalo)
Ishak Isa (Universitas Negeri Gorontalo)
Karunita Ika Astuti (Universitas Negeri Gorontalo)

Obat: Jurnal Riset Ilmu Farmasi dan Kesehatan
Vol. 4 No. 5 (2026): September : OBAT: Jurnal Riset Ilmu Farmasi dan Kesehatan

This study aimed to determine the antibacterial activity of the combined ethanol extracts of miana leaves (Coleus scutellarioides L.) and guava leaves (Psidium guajava) against Escherichia coli and to evaluate their interaction using the CompuSyn method. This laboratory experimental study employed maceration extraction with 96% ethanol, followed by phytochemical screening, antibacterial testing using the disc diffusion method, One-Way ANOVA, and Combination Index (CI) analysis. The extraction yielded 11.11% for miana leaves and 24.92% for guava leaves. Phytochemical screening confirmed the presence of flavonoids and alkaloids in both extracts. All extract combinations inhibited E. coli growth, producing inhibition zones ranging from 8.10 to 12.75 mm, indicating moderate to strong antibacterial activity. One-Way ANOVA showed no significant differences among treatment groups (p = 0.837). CompuSyn analysis revealed that most combinations exhibited antagonistic interactions (CI > 1), whereas the combination of 10% guava extract and 20% miana extract showed synergistic effects (CI < 1) in two replicates. Overall, the combined extracts demonstrated antibacterial activity against E. coli, although most combinations did not exhibit synergistic interactions.