Effects of Standardized Eriobotrya japonica Extract in LP-BM5 Murine Leukemia Viruses-Induced Murine Immunodeficiency Syndrome.

Folk medicine has long employed leaves from Eriobotrya japonica Lindl. (Rosaceae) (LEJ) as relieving many diseases including chronic bronchitis and high fever. In this study, we investigated the immunomodulatory effects of leaves from LEJ water extracts (LEJE) in LP-BM5 murine leukemia viruses (MuLV)-induced immune-deficient animal model. Dietary supplementation of LEJE (100, 300, 500 mg/kg) began on the day of LP-BM5 MuLV infection and continued for 12 weeks. Dietary supplementation of LEJE inhibited LP-BM5 MuLV-induced splenomegaly and lymphadenopathy. Moreover, LEJE attenuated reductions of T- and B-cell proliferation and Th1/Th2 cytokine imbalance in LP-BM5. We found that dietary supplements of LEJE suppressed the hypergammaglobulinemia by ameliorating LP-BM5 MuLV infection-induced B-cell dysfunction and production of pro-inflammatory cytokines. We suggest that Eriobotrya japonica may have beneficial immunomodulatory effects, improving the balance of Th1/Th2 cytokines and anti-inflammatory effects.