You-Zhi Wang,Yu-Long Wang,Hao-Jie Che,Yi-He Jia,Hui-Fang Wang,Lin-Fei Zuo,Kan Yang,Ting-Ting Li,Jin-Xin Wang
Ethnopharmacological relevance Sumu ( Lignum sappan ), the dry heartwood of Caesalpinia sappan L., is a traditional Chinese medicine used as an analgesic and anti-inflammatory agent. Aim of the study The study aspired to discover natural phosphodiesterase 4 (PDE4) inhibitors with dual anti-inflammatory and antioxidant activities from Sumu for the treatment of chronic obstructive pulmonary disease (COPD). Materials and methods To accurately and efficiently identify natural PDE4 inhibitors from Sumu, molecular docking and molecular dynamics (MD) analysis methods were used for structure-based virtual screening of a self-built database of primary polyphenols in Sumu. According to the previous studies of Sumu and the free radical scavenging mechanism of polyphenols, the reported antioxidant components from Sumu and the potential antioxidants with the antioxidant pharmacophore of catechol and π-conjugated moieties were selected from the potential PDE4 inhibitors predicted by docking. Sappanone A, a potential PDE4 inhibitor with antioxidant activity from Sumu, was selected, calculated and synthesized to evaluate its dual anti-inflammatory and antioxidant functions in vitro and in vivo studies. Herein sappanone A was assayed for its inhibitory effects against PDE4 enzyme activity, tumor necrosis factor-alpha (TNF-α) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophages and malondialdehyde (MDA) production induced by Fe 2+ in mouse lung homogenate; sappanone A was also assayed for its abilities of radical (DPPH) scavenging, reducing Fe 3+ and complexing Fe 2+ in vitro. Additionally, LPS-induced acute lung injury (ALI) in mice was used to evaluate its anti-inflammatory activity as a PDE4 inhibitor in vivo, and the levels of TNF-α and total protein in bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) activity in the lung were assayed. Results The present study predicted and validated that sappanone A was a promising PDE4 inhibitor from Sumu with dual anti-inflammation and antioxidant activities from Sumu. In vitro, sappanone A remarkably inhibited PDE4 enzyme activity and reduced TNF-α production induced by LPS in RAW264.7 macrophages and MDA production induced by Fe 2+ in mouse lung homogenate. Meanwhile, it showed outstanding abilities of scavenging DPPH radicals, reducing Fe 3+ and complexing Fe 2+ . In vivo, sappanone A (25 mg/kg and 50 mg/kg, i.p., twice daily for 7 days) distinctly prevented LPS-induced ALI in mice by reducing the levels of TNF-α and total protein in BALF and MPO activity in the lung. Conclusion Sappanone A is a natural PDE4 inhibitor with dual anti-inflammatory and antioxidant activities from the traditional Chinese medicine Sumu, which may be a promising therapeutic agent to prevent the vicious cycle of COPD inflammation and oxidative stress.
Youzhi Wang,Huifang Wang,Guoqing Yang,Qingjing Hao,Kan Yang,Huizhen Shen,Yulong Wang,Jinxin Wang
It is well known that chronic obstructive pulmonary disease (COPD) patients are always trapped in the vicious circle of inflammation and oxidative stress , therefore anti-inflammatory and antioxidant bifunctional agents may interrupt this vicious cycle in COPD. Phosphodiesterase 4 (PDE4) inhibitors, as anti-inflammatory drugs, have been used for COPD treatment in clinical, and the PDE4 inhibitors with antioxidant properties may be a good strategy to design bifunctional agents for COPD. Sappanone A was the first PDE4 inhibitor with antioxidant properties we identified from natural products in our previous study, which was used by us as a hit compound to design new bifunctional agents for COPD in this study. 27 derivatives of sappanone A including homoisoflavonoids , aurones and chalcones were designed and synthesized by innovatively fusing the antioxidant pharmacophore of catechol from polyphenols and the pharmacophore of catechol ether abstracted from the PDE4 inhibitors of the catechol ether class such as rolipram , roflumilast and apremilast respectively. All the compounds were assayed for the PDE4 inhibitory and radical scavenging against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) activities in vitro. Herein we obtained a series of bifunctional compounds with better PDE4 inhibitory activity than sappanone A, and their free radical scavenging activities were superior to edaravone in vitro. In addition, they can reduce tumour necrosis factor-alpha (TNF-α) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophages and malondialdehyde (MDA) production induced by Fe 2+ in mouse lung homogenate . Meanwhile, it showed outstanding abilities in reducing Fe 3+ and complexing Fe 2+ . 6o , as the candidate anti-inflammatory and antioxidant bifunctional compound, exhibited good drug-likeness, ADME (Absorption, Distribution, Metabolism, Excretion) properties and human liver microsomal stability. In vivo, 6o (50 mg/kg and 100 mg/kg, i. p.) distinctly prevented LPS-induced serum levels of TNF-α in mice. In conclusion, the preliminary investigation provided a novel class of PDE4 inhibitors with antioxidant properties as bifunctional agents for the potential treatment of COPD, which can interrupt the vicious cycle of chronic inflammation and oxidative stress in COPD.