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Sipjeondaebo-tang (SDT) is used frequently as a herbal prescription to treat deficiency syndromes in traditional Korean medicine. We investigated the hepatoprotective effects of SDT against oxidative stress and attempted to clarify the underlying molecular mechanisms. SDT pretreatment reduced arachidonic acid (AA) plus iron-mediated cytotoxicity in a concentration-dependent manner and prevented changes in apoptosis-related protein expression. In addition, SDT pretreatment significantly reduced glutathione depletion, hydrogen peroxide production, and mitochondrial dysfunction via treatment with AA plus iron. SDT increased the phosphorylation of AMP-activated protein kinase (AMPK) in accordance with the phosphorylation of Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2). Experiments using an AMPK chemical inhibitor (Compound C) or CaMKK2 chemical inhibitor (STO-609) suggested that the CaMKK2-AMPK signaling pathway contributes to SDT-mediated protection of mitochondria and cells. Moreover, administration of SDT for 4 consecutive days to mice significantly reduced the alanine aminotransferase and aspartate aminotransferase activities induced by carbon tetrachloride, and the numbers of degenerated hepatocytes, infiltrated inflammatory cells, nitrotyrosine-positive cells, and 4-hydroxynonenal-positive cells in liver tissue. Therefore, SDT protects hepatocytes from oxidative stress via CaMKK2-dependent AMPK activation and has the therapeutic potential to prevent or treat oxidative stress-related liver injury.

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High blood pressure (BP) is a highly controllable risk factor for cardiovascular diseases; however, awareness of this condition and the rates of controlled hypertension are low. Experimental animal studies have shown that stimulation of the median nerve or PC6 acupoint over the wrist has effects on cardiovascular activities, including reductions in systolic and diastolic BPs. A proof-of-concept study was conducted in humans to investigate whether stimulation of median nerve near PC6 acupoint decreased high BP, identify the optimal stimulation parameters for the BP-lowering effects of median nerve stimulation, and determine the specific peripheral nerves or types of afferent fibers mediating the BP-lowering effects. Median nerve stimulation was carried out bilaterally or unilaterally with different stimulation parameters, and the BP and heart rate were monitored. The afferent mechanisms underlying the effects of median nerve stimulation on hypertension were investigated via microneurography, A-fiber blocking experiments, and localized chemical or electrical stimulation. Bilateral median nerve stimulation at either low or high frequencies produced profound but transient reductions in systolic BP, which were elicited when median nerve stimulation was unilaterally applied at interelectrode distances of 2 and 4 cm. Systolic BP was also reduced by electrical stimulation of the thumb on the palm side. Although microneurographic recordings revealed the excitation of both A- and C-fibers following median nerve stimulation, the median nerve-mediated reductions in BP were not affected by A-fiber blockade, and they were mimicked by the activation of C-fibers with capsaicin. The present results indicate that activation of C-fibers in the median nerve generates BP-lowering effects in humans. Based on our clinical study, an optimized median nerve stimulator was built and combined with a wrist BP monitor for simultaneous BP measurements and median nerve stimulation.

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RESUMEN

AIMS: Betula platyphylla (B. platyphylla) has traditionally been used in Korea to treat inflammatory diseases. However, the exact mechanism that accounts for the anti-inflammatory effect of B. platyphylla is not completely understood. The aim of the present study is to elucidate whether and how B. platyphylla modulates the mast cell-mediated allergy inflammation in vitro and in vivo. MAIN METHODS: We investigated to ascertain the pharmacological effects of B. platyphylla on both compound 48/80 or histamine-induced scratching behaviors and 2, 4-dinitrochlrobenzene (DNCB)-induced atopic dermatitis in mice. Additionally, to find a possible explanation for the anti-inflammatory effects of B. platyphylla, we evaluated the effects of B. platyphylla on the release of histamine in compound 48/80-induced rat peritoneal mast cells (RPMCs), production of inflammatory mediators and activation of nuclear factor-κB (NF-κB) and caspase-1 in phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated human mast cells (HMC-1). KEY FINDINGS: The finding of this study demonstrated that B. platyphylla reduced compound 48/80 or histamine-induced scratching behaviors and DNFB-induced atopic dermatitis in mice. Additionally, B. platyphylla inhibited the release of histamine in RPMC and production of inflammatory cytokines as well as the activation of NF-κB and caspase-1 in stimulated HMC-1. SIGNIFICANCE: Collectively, the findings of this study provide us with novel insights into the pharmacological actions of B. platyphylla as a potential molecule for use in the treatment of allergic inflammatory diseases.

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