Recent advances of basic research and clinical application of lactoferrin as an antiviral reagent against chronic hepatitis C

Hepatitis C virus(HCV), discovered in 1989, is the major causative agent of chronic viral hepatitis. Most patients progress to liver cirrhosis and hepatocellular carcinoma. In the therapy of hepatitis C, only interferon has been used effectively as an anti-HCV reagent in Japan, but its effectiveness is limited to about 30% of cases. Using human hepatocyte cell line which could support efficient HCV replication, we previously found that lactoferrin inhibited HCV infection, and demonstrated that this inhibiting activity was due to the interaction of lactoferrin with HCV. Further analysis found that the carboxyl region of lactoferrin, which partially shows amino acid sequence homology to human CD81, specifically bound to the HCV E2 envelope protein, and identified a 33 amino acids as a critical binding domain of lactoferrin. On the other hand, it has been shown that bovine lactoferrin was effective in some patients with chronic hepatitis received an 8-week course of lactoferrin treatment. Further clinical trials showed that lactoferrin is a promising candidate for adjuvant therapy with interferon in patients with chronic hepatitis C.