Immune Enhancing Effects of Aqueous Extracted Black Raspberry in Diet-induced Hyperlipidemia Mice

As obese population has increased today, metabolic diseases accompanied with obesity have been issued as well. Hyperlipidemia, one of those metabolic abnormalities, is commonly diagnosed with obesity. It is also associated with inflammation and immune dysfunctions, which can be led to global immune decline as the host ages. In this study, the potential effects of black raspberry on the diet-induced hyperlipidemia were examined in terms of immunology. We first induced hyperlipidemia in mice by feeding with 45kcal high fat diet (HFD) for 23 weeks and the progress of disease was traced by blood lipid profiling. Oral administration of black raspberry then proceeded for 16 weeks. As a result, the lymphocyte subset populations such as CD4 + , CD8 + and CD11c + were quantitatively restored by black raspberry treatment. The proliferation and cytokine production of lymphocytes were also normalized in black raspberry treated mice. Regarding specific immunity, oral administration of black raspberry significantly restored both cellular and humoral immune function as determined by in vivo cytotoxic T lymphocytes (CTLs) assay and specific immunoglobulin G (IgG) production level. Lastly the lipid indices including total cholesterol and HDL were considerably improved by black raspberry treatment, indicating the therapeutic effect of black raspberry on hyperlipidemia. That is, not only practical improvement in hyperlipidemia, but also the immune-enhancing effect of black raspberry was newly elucidated with quantitative and qualitative evidences.