Figure 4
![Figure 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1472-6882-14-296/MediaObjects/12906_2013_Article_1874_Fig4_HTML.jpg)
Levodopa concentrations obtained alter the oral administration of 100:25 mg/kg levodopa/carbidopa in the three groups studied (initial situation blue triangle; treatment with Plantago ovata husk green circle and treatment with placebo red square) to 18 Parkinson patients. Volunteers 13 to 18.