A heart with the medicinal plants including hawthorn, advertising Zeller's heart and nerve drops (medicine). Colour lithograph by A. Engel, 1944 (?).

A dew drop falls from the plants on to the heart. The firm of Zeller A.G. specializes in the manufacture of herbal remedies. It was founded by Max Zeller in Romanshorn, Thurgau, Switzerland, in 1864. Its heart and nerve-drops contain extracts from hawthorn leaves, flowers and berries (information from the website of the company, 2007). "Hawthorn extract can significantly ease the symptoms of chronic heart failure, research suggests. Researchers identified 14 trials that compared the effects of adding either hawthorn extract, or a placebo to conventional therapies. The results indicated that the extract increased the maximum workload that patients could endure. It also decreased the amount of oxygen used by the heart"--Daily telegraph, 23 January 2008