Department of Complex Prescription of TCM, Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Research, China Pharmaceutical University, 639 Longmian Road, Nanjing 211198, China.
Divsion of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, BMC box 574, S-751 23 Uppsala, Sweden.
Molecules. 2017 Aug 29;22(9):1392. doi: 10.3390/molecules22091392.
Licorice derived from the roots and rhizomes of . (Fabaceae), is one of the most widely-used traditional herbal medicines in China. It has been reported to possess significant analgesic activity for treating spastic pain. The aim of this study is to investigate the spasmolytic molecular mechanism of licorice on oxytocin-induced uterine contractions and predict the relevant bioactive constituents in the aqueous extract. The aqueous extraction from licorice inhibited the amplitude and frequency of uterine contraction in a concentration-dependent manner. A morphological examination showed that myometrial smooth muscle cells of oxytocin-stimulated group were oval-shaped and arranged irregularly, while those with a single centrally located nucleus of control and licorice-treated groups were fusiform and arranged orderly. The percentage of phosphorylation of HSP27 at Ser-15 residue increased up to 50.33% at 60 min after oxytocin stimulation. Furthermore, this increase was significantly suppressed by licorice treatment at the concentration of 0.2 and 0.4 mg/mL. Colocalization between HSP27 and α-SMA was observed in the myometrial tissues, especially along the actin bundles in the oxytocin-stimulated group. On the contrary, the colocalization was no longer shown after treatment with licorice. Additionally, employing ChemGPS-NP provided support for a preliminary assignment of liquiritigenin and isoliquiritigenin as protein kinase C (PKC) inhibitors in addition to liquiritigenin, isoliquiritigenin, liquiritin and isoliquiritin as MAPK-activated protein kinase 2 (MK2) inhibitors. These assigned compounds were docked with corresponding crystal structures of respective proteins with negative and low binding energy, which indicated a high affinity and tight binding capacity for the active site of the kinases. These results suggest that licorice exerts its spasmolytic effect through inhibiting the phosphorylation of HSP27 to alter the interaction between HSP27 and actin. Furthermore, our results provide support for the prediction that potential bioactive constituents from aqueous licorice extract inhibit the relevant up-stream kinases that phosphorylate HSP27.
甘草来源于. (豆科)的根和根茎，是中国应用最广泛的传统草药之一。据报道，它具有显著的镇痛活性，可用于治疗痉挛性疼痛。本研究旨在探讨甘草水提物对催产素诱导的子宫收缩的解痉作用机制，并预测水提物中相关的生物活性成分。甘草水提物呈浓度依赖性抑制子宫收缩的幅度和频率。形态学检查显示，催产素刺激组的子宫平滑肌细胞呈椭圆形，排列不规则，而对照组和甘草处理组的子宫平滑肌细胞呈梭形，排列有序，中央有一个核。催产素刺激 60 分钟后，HSP27 在丝氨酸 15 残基的磷酸化百分比增加到 50.33%。此外，甘草在 0.2 和 0.4 mg/mL 浓度下可显著抑制这种增加。在子宫组织中观察到 HSP27 与 α-SMA 的共定位，尤其是在催产素刺激组的肌动蛋白束中。相反，甘草处理后不再显示共定位。此外，ChemGPS-NP 的应用支持初步将甘草素和异甘草素鉴定为蛋白激酶 C (PKC)抑制剂，此外，甘草素、异甘草素、甘草苷和异甘草苷还可作为丝裂原激活蛋白激酶 2 (MK2)抑制剂。这些指定的化合物与相应蛋白的晶体结构对接，结合能为负且低，这表明它们与激酶的活性位点具有高亲和力和紧密结合能力。这些结果表明，甘草通过抑制 HSP27 的磷酸化来发挥其解痉作用，从而改变 HSP27 与肌动蛋白的相互作用。此外，我们的结果支持这样的预测，即来自甘草水提物的潜在生物活性成分抑制了磷酸化 HSP27 的相关上游激酶。
