Effects of commercial citrate-containing juices on urolithiasis in a Drosophila model

Diet modification plays an important role in nephrolithiasis. Development of an easy, ready-to-use beverage such as a commercial juice drink to use as a preventive treatment for renal calculi formation would be widely welcomed. We previously developed a novel Drosophila model for the study of nephrolithiasis. It provides a new well-established drug discovery platform for this common disease. In our current study, we used the Drosophila model to investigate the preventive effects of various commercial juices as potential treatments for nephrolithiasis. Our results showed that apple, cranberry, orange, and pomegranate juices failed to reduce calcium oxalate (CaOx) crystal formation, whereas our positive control—potassium citrate (K-citrate)—significantly prevented CaOx crystal formation. Unlike the commercial fruit juices that were tested, the administration of K-citrate significantly ameliorated the ethylene glycol (EG)-induced life-span reduction in treated flies. These results indicate that EG-induced CaOx nephrolithiasis in Drosophila can be prevented by K-citrate, but not by commercial citrate-containing juices. However, the inhibitory capability of citrate-containing juices to reduce renal stone formation in humans requires further elucidation.