Effect of blueberry on hepatic and immunological functions in mice

BACKGROUND: Conventional drugs used in the treatment and prevention of liver diseases often have side effects, therefore research into natural substances are of significance. This study examined the effects of blueberry on liver protection and cellular immune functions. METHODS: To determine the effects of blueberry on liver protective function, male mice were orally administered blueberry (0.6 g/10 g) or normal saline for 21 days. Hepatic RNA was extracted by Trizol reagent, and the expression of Nrf2, HO-1, and Nqol was determined by real-time RTPCR. Superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenate were determined, and liver index was measured. To assess the effects of blueberry on cellular immune function, male mice received blueberry (0.4, 0.6, or 0.8 g/10 g) for 35 days, and the percentages of CD3(+), CD41(+), and CDS+ T lymphocyte subgroups in peripheral blood were detected by flow cytometry, the index of the thymus and spleen was measured, and lymphocyte proliferation in the spleen was determined by MTT assay. RESULTS: Blueberry treatment significantly increased the expression of Nrf2, HO-1, and Nqol, the important antioxidant components in the liver. Hepatic SOD in the blueberry group was higher and MDA was lower than that in the control group (P<0.05). Blueberry also increased the index of the spleen and enhanced the proliferation of lymphocytes of the spleen (P<0.05). The percentages of the CD3(+) and CDA(+) T lymphocyte subsets and the CD4(+)/CD8(+) ratio were also increased by blueberry (P<0.05). CONCLUSIONS: Blueberry induces expression of Nrf2, HO-1, and Nqol, which can protect hepatocytes from oxidative stress. In addition, blueberry can modulate T-cell function in mice. (Hepatobiliary Pancreat Dis Int 2010; 9: 164-168)