Cynara cardunculus var. cardunculus L., also known as cardoon, is a perennial weed naturalized in the Pampas region of Argentina. A quantification of cynarine and chlorogenic acid of callus and leaves from cardoon was performed by means of micellar electrokinetic capillary chromatography, showing that the content of cynarine is higher in calluses than in vivo leaves. The scavenging effect of the callus extract, determined by the thiobarbituric acid method, demonstrated its significant antioxidant capacity. The obtained results revealed that in vitro tissue culture is an excellent tool for producing cynarine for therapeutical purposes.