Recovery Effect of a Rutin-Enriched Fraction Prepared From Forsythia koreana Flowers on Alloxan-Induced Pancreatic Islets in Zebrafish Larvae (Danio rerio)

A simple method to prepare a high-content rutin fraction from Forsythia koreana flowers (HRFK) is described. Rutin, isolated for the first time from the flowers, was identified from spectroscopic data including nuclear magnetic resonance, mass spectrometry, and infrared. As a result of HPLC quantitative analysis, the content of rutin was found to be 80.0 ± 0.02% in HRFK. Our previous study reported that F koreana MeOH extract (FK) significantly recovered alloxan-induced pancreatic islets in zebrafish. However, HRFK as well as rutin exhibited an enhanced anti-diabetic effect compared to FK in our latest experiments. In conclusion, HRFK, as well as rutin and FK, have potential as anti-diabetic agents.