Antimicrobial Activity of Ag-NPs, Oil, and Extract

The minimum inhibitory concentration (MIC) values of Ag-NPs, oil, and extract were determined by broth microdilution assay. The Ag-NPs were serially diluted two-fold with deionized water in concentrations ranging from 5.00 to 7.812 μg/mL. The oil and extract were serially diluted two-fold with 10% dimethyl sulfoxide (DMSO) (Merck, Germany) containing 1.00 - 1.56 mg/mL of oil. After shaking, 100 mL of diluted Ag-NPs, oil, and extract was added to each well of 96-well microtiter plates. Cation-adjusted Muller-Hinton broth (Merck, Germany) was used as the broth medium. Microbial suspensions were adjusted to 0.5 MacFarland and diluted to 1 × 10⁶ CFU/mL, then 100 mL of the suspension was added to each well and incubated at 35 ± 2°C for 24 hours. MIC values were determined as the lowest concentration of compound that inhibited bacteria after 24 hours (17 (link), 18 ).