Acorbine, a Corbicula japonica-derived tripeptide containing non-proteinogenic amino acids, suppresses ethanol-induced liver injury.

Since ancient times, Corbicula extract has been believed in Japan to have hepatoprotective effects, but it remains unclear whether these claims are true, and if so, which component is responsible for hepatoprotection. In this study, we showed that Corbicula extract exerted a protective effect against liver damage. Recent work identified acorbine (ß-alanyl-ornithyl-ornithine), a novel tripeptide containing non-proteinogenic amino acids, in the extract of Corbicula japonica. Synthesized acorbine cured alcohol-induced liver damage in mice. In addition, acorbine purified from Corbicula extract exerted a protective effect against alcohol-induced hepatotoxicity in a culture liver model derived from mouse ES/iPS cells. Thus, acorbine is one of the components of Corbicula extract that protects hepatocytes against ethanol-induced death.

Influence of low-temperature processing of the brackish-water bivalve, Corbicula japonica, on the ornithine content of its extract.

The ornithine content of an extract of the brackish-water bivalve, Corbicula japonica, increased when the bivalve was frozen. It was not influenced by the period of freezing. This phenomenon was not apparent in the scallop, little-neck clam, or hard clam. We applied various low-temperature conditions for processing the bivalve from 4 degrees C to -10 degrees C and measured the ornithine content of each extract. The ornithine content was maximized by processing at - 4 degrees C. The increase in this ornithine content was reduced when the bivalve was stored at 5 degrees C or 15 degrees C after processing at - 4 degrees C, this decrease being reversed when the bivalve was again processed at - 4 degrees C after warming. Low-temperature processing of the brackish-water bivalve therefore increased the ornithine content of the extract.