Antineuropathic pain actions of Wu-tou decoction resulted from the increase of neurotrophic factor and decrease of CCR5 expression in primary rat glial cells.

Wu-tou decoction (WTD), a classic Traditional Chinese medicine formula, has been extensively used in the treatment of neuropathic pain (NP) such as chronic inflammatory pain, trigeminal neuralgia, and cancer-induced pain. Our previous studies have shown that the severity of mechanical allodynia and thermo hypersensitivity in NP rats are reduced by WTD, of which analgesic candidates are paeoniflorin (Pae) and liquiritin (Liq). The aim of this study was to clarify the molecular mechanisms of WTD, Pae and Liq against NP based on the primary rat glial cells in vitro. The gene expression levels of neurotrophic factors such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and Artemin and C-C chemokine receptor type 5 (CCR5) were augmented by inflammatory cytokines, while chemokines increased only CCR5 gene expression. The constitutive and cytokine-augmented neurotrophic factor gene expression was enhanced by WTD, Pae, and Liq through PI3K- and PKA-dependent pathways in rat glial cells, leading to the increase of NGF and BDNF production. Furthermore, the CCR5 gene expression under basal and chemokine-treated conditions was suppressed by these reagents, in which signal pathway(s) was independent on the activation of PI3K and PKA. Moreover, there was no cytotoxicity in the WTD, Pae, and Liq treatments in glial cells. Thus, these results provide a novel evidence that WTD may exert the anti-NP actions by predominantly increasing the production of neurotrophic factors through PI3K- and PKA-signaling pathways in rat glial cells. Furthermore, Pae and Liq may play as analgesic candidates in WTD-mediated NP management.

Involvement of Catechols in Acteoside in the Activation of Promatrix Metalloproteinase-2 and Membrane Type-1-Matrix Metalloproteinase Expression via a Phosphatidylinositol-3-Kinase Pathway in Human Dermal Fibroblasts.

Granulation tissue formation during skin wound healing requires the migration and proliferation of dermal fibroblasts in the wound site, where a subsequent remodeling of extracellular matrices (ECM) occurs. An abnormality of ECM remodeling within the healing wound leads to fibrosis and a contracted scar. To evaluate whether acteoside, a phenylethanoid glycoside isolated from the leaves of Rehmannia glutinosa LIBOSCH., exhibits wound-healing actions, we examined the effect of acteoside on the expression of matrix metalloproteinases (MMPs) in normal human dermal fibroblasts (NHDF). Acteoside dose- and time-dependently augmented the activation of the precursor of MMP-2 (proMMP-2/progelatinase A) in untreated- and interleukin-1ß-treated NHDF, while the alteration of the MMP-2 gene expression was negligible. The acteoside-induced proMMP-2 activation was associated with the augmented membrane-type 1 MMP (MT1-MMP) expression in the NHDF. In addition, the proMMP-2 activation was enhanced by two aglycones in acteoside: caffeic acid and 3,4-dihydroxyphenylethanol, which consist of catechol. However, there was no change in the proMMP-2 activation in other catechol derivatives: homovanillyl alcohol- and homovanillic acid-treated NHDF, indicating that catechols in acteoside were requisite for the regulation of the MMP activation and expression in NHDF. Furthermore, the proMMP-2 activation by acteoside was selectively inhibited by LY294002, a potent phosphatidylinositol-3-kinase (PI3K) inhibitor. These results provide novel evidence that acteoside augments proMMP-2 activation along with an increase in MT1-MMP expression through a PI3K signal pathway in NHDF. Thus, acteoside is likely to be an attractive candidate that facilitates ECM remodeling in the skin wound repair process.