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)

Effects of blueberry on hepatic fibrosis and transcription factor Nrf2 in rats

AIM:To investigate the effects of blueberry on hepatic fibrosis and NF-E2-related factor 2(Nrf2) transcription factor in rats.METHODS:Forty-five male Sprague-Dawley rats were randomly divided into control group(A);CCl4-induced hepatic fibrosis group(B);blueberry prevention group(C);Dan-shao-hua-xian capsule(DSHX) prevention group(D);and blueberry + DSHX prevention group(E).Liver fibrosis was induced in rats by subcutaneous injection of CCl4 and a high-lipid/low-protein diet for 8 wk(except the control group).The level of hyaluronic acid(HA) and alanine aminotransferase(ALT) in serum was examined.The activity of superoxide dismutase(SOD),glutathione-S-transferase(GST) and malondialdehyde(MDA) in liver homogenates was determined.The degree of hepatic fibrosis was evaluated by hematoxylin and eosin and Masson staining.Expression of Nrf2 and NADPH quinone oxidoreductase 1(Nqo1) was detected by real-time reversed transcribed-polymerase chain reaction,immunohistochemical techniques,and western blotting.RESULTS:Compared with group B,liver indices,levels of serum HA and ALT of groups C,D and E were reduced(liver indices:0.038 ± 0.008,0.036 ± 0.007,0.036 ± 0.005 vs 0.054 ± 0.009,P<0.05;HA:502.33 ± 110.57 ng/mL,524.25 ± 255.42 ng/mL,499.25 ± 198.10 ng/mL vs 828.50 ± 237.83 ng/mL,P<0.05;ALT:149.44 ± 16.51 U/L,136.88 ± 10.07 U/L,127.38 ± 11.03 U/L vs 203.25 ± 31.62 U/L,P<0.05),and SOD level was significantly higher,but MDA level was lower,in liver homogenates(SOD:1.36 ± 0.09 U/mg,1.42 ± 0.13 U/mg,1.50 ± 0.15 U/mg vs 1.08 ± 0.19 U/mg,P<0.05;MDA:0.294 ± 0.026 nmol/mg,0.285 ± 0.025 nmol/mg,0.284 ± 0.028 nmol/mg vs 0.335 ± 0.056 nmol/mg,P<0.05).Meanwhile,the stage of hepatic fibrosis was significantly weakened(P<0.05).Compared with group A,the activity of GST liver homogenates and expression levels of Nrf2 and Nqo1 in group B were elevated(P<0.05).The expression level of Nrf2 and Nqo1 in groups C,D,and E were increased as compared with group B,but the difference was not significant.CONCLUSION:Blueberry has preventive and protective effects on CCl4-induced hepatic fibrosis by reducing hepatocyte injury and lipid peroxidation.However,these effects may not be related to the activation of Nrf2 during long-term of CCl4.