Advanced analytical techniques have recently revealed powerful health-promoting properties in components of some plants, which had remained obscure until present days because they were not typically consumed as food by humans. A particularly fascinating example is the seed kernel of sour cherry (Prunus cerasus). Chemical analysis of the seed kernel revealed that the solid flavonoid-rich fraction, comprising approximately 64–68% of the kernel, contains several health-enhancing polyphenolic compunds including catechins, stillbenes, anthocyanidins and resveratrol. The remaining 32–36% is an oil fraction rich in tocopherols and related compounds, including tocotrienols, oleic acid and triglycerides. Previous studies demonstrated that oral administration of sour cherry seed extract to animals strongly stabilizes healthy tissue homeostasis and suppresses ischemia-reperfusion injury by augmenting expression of heme oxygenase-1, a major endogenous cytoprotective enzyme. The sour cherry fruit is a major export of several nations, including Hungary, however the seed is currently considered an agricultural by-product and discarded. The better understanding of health protective effects of the seed extract would open new avenues for the Hungarian agriculture and food industry in the future.