Glycogen synthase kinase-3β (GSK-3β) acts as a negative regulator of NF-E2 related factor 2 (Nrf2) by inducing Nrf2 degradation and nuclear export. Our previous study demonstrated that the flavonoid hyperoside elicits cytoprotection against oxidative stress by activating the Keap1-Nrf2-ARE signaling pathway, thus increasing the expression of antioxidant enzymes, such as heme oxygenase-1 (HO-1), superoxide dismutase (SOD) and catalase. However, the role of GSK-3β in hyperoside-mediated Nrf2 activation is unclear. Here, we demonstrate that in a normal human hepatocyte cell line, (L02), hyperoside is capable of inducing the phosphorylation of GSK-3β at Ser9 without affecting the protein levels of GSK-3β and its phosphorylation at Thr390. Lithium chloride (LiCl) and short interfering RNA (siRNA)-mediated inhibition of GSK-3β significantly enhanced the ability of hyperoside to protect L02 liver cells from H2O2-induced oxidative damage, leading to increased cell survival shown by the maintenance of cell membrane integrity and elevated levels of glutathione (GSH), one of the endogenous antioxidant biomarkers. Further study showed that LiCl and siRNA-mediated inhibition of GSK-3β increased hyperoside-induced HO-1 expression, and the effect was dependent upon enhanced Nrf2 nuclear translocation and gene expression. These activities were followed by ARE-mediated transcriptional activation in the presence of hyperoside, which was abolished by the transfection of the cells with Nrf2 siRNA. Furthermore, the siRNA-mediated inhibition of Keap1 also enhanced hyperoside-induced Nrf2 nuclear accumulation and HO-1 expression, which was relatively smaller than the effects obtained from GSK-3β siRNA administration. Moreover, Keap1 siRNA administration alone had no significant effect on the phosphorylation and protein expression of GSK-3β. Collectively, our data provide evidence that hyperoside attenuates H2O2 -induced L02 cell damage by activating the Nrf2-ARE signaling pathway through both an increase in GSK-3β inhibitory phosphorylation at Ser9 and an inhibition of Keap1 and that hyperoside-mediated GSK-3β inhibition exhibits more significant effects.

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BackgroundMigraine has been recognized as one of the leading causes of disability in the 2013 Global Burden of Disease Study and seriously affects the quality of patients’ life, current treatment options are not ideal. Monoclonal antibodies to calcitonin gene-related peptide and its receptor (CGRP-mAbs) appear more promising for migraine because of considerably better effect and safety profiles. The objective of this study is to systematically assess the clinical efficacy and safety of CGRP-mAbs for migraine therapy.MethodsA systematic literature search in PubMed, Cochrane Library and Baidu Scholar was performed to identify randomized controlled trials (RCTs), which compared the effect and safety of CGRP-mAbs with placebo on migraine. Regarding the efficacy, the reduction of monthly migraine days from baseline to weeks 1–4, 5–8, and 9–12; responder rates were extracted as the outcome measures of the effects of CGRP-mAbs. Regarding the safety, total adverse events, the main adverse events, and other adverse events were evaluated.ResultsWe found significant reduction of monthly migraine days in CGRP-mAbs vs. placebo (weeks 1–4: SMD −0.49, 95% CI −0.61 to −0.36; weeks 5–8: SMD −0.43, 95% CI −0.56 to −0.30; weeks 9–12: SMD −0.37, 95% CI −0.49 to −0.24). 50% and 75% responder rates (OR 2.59, 95% CI 1.99 to 3.37; and OR 2.91, 95% CI 2.06 to 4.10) were significantly increased compared with placebo. There was no significant difference in total adverse events (OR 1.17, 95% CI 0.91 to 1.51), and the main adverse events including upper respiratory tract infection (OR 1.44, 95% CI 0.82 to 2.55), nasopharyngitis (OR 0.59, 95% CI 0.30 to 1.16), nausea (OR 0.61, 95% CI 0.29 to 1.32), injection-site pain (OR 1.73, 95% CI 0.95 to 3.16) and back pain (OR 0.97, 95% CI 0.49 to 1.90) were not obviously changed compared with placebo control, but the results showed significant increase of dizziness in CGRP-mAbs vs. placebo (OR 3.22, 95% CI 1.09 to 9.45).ConclusionsThis meta-analysis suggests that CGRP-mAbs are effective in anti-migraine therapy with few adverse reactions, but more and larger sample-size RCTs are required to verify the current findings.

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