Fig 3. C. difficile toxin inhibition by natural products and control antibiotics (vancomycin and fidaxomicin).

C. difficile was incubated with subinhibitory concentrations of drugs for 12 hours. Viable cells (log₁₀ CFU/ml, bars) in each sample were determined by plating and the amount of toxin in each supernatant (OD₄₅₀-OD₆₂₀, lines) was assessed using ELISA. The data represents the mean and standard deviation for triplicate samples of each treatment. Asterisk (*) indicates a statically significant difference in the toxin content of the supernatant between the fidaxomicin- or natural product-treated samples and the untreated control.