Dried powdered of plant samples (10 mg) were weighted, extracted with 500 μL methanol and then sonicated for 15 min. The extracts were centrifuged at 3,000 rpm for 3 minutes to collect the supernatant. This extraction procedure was repeated four times. The combined extract were evaporated at 50°C and re-dissolved in 1 mL methanol. Consequently, sample solutions were diluted into appropriated concentrations. The MuA concentrations were determined by indirect competitive ELISA using polyclonal antibody against MuA.