Pharmacology department, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
Pharmacognosy department, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran; Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
Prostaglandins Other Lipid Mediat. 2020 Oct;150:106473. doi: 10.1016/j.prostaglandins.2020.106473. Epub 2020 Jul 4.
Euphorbia is a large genus of flowering plants. In Iran, some plants of this family have been used in the treatment of inflammatory disorders and also to relieve back pain. Euphorbia spinidens is a rich source of Cycloarta-23-ene-3beta,25-diol. Cycloartane structures are the starting material for the synthesis of plant steroids, and the aim of this study is to demonstrate COX inhibitory activity, molecular docking and in vivo approach of anti-inflammatory activity of cycloartane compound isolated from Euphorbia spinidens.
Plant material was extracted with acetone-chloroform and submitted to column chromatography for fractionation. Based on preliminary H-NMR spectra, cycloartane fraction was selected and purified by repeated recycle HPLC system. The structure and purity of compound were determined by H and C-NMR, HPTLC, and mass spectra. Inhibitory activities of the tested compounds on COX-1 and COX-2 were evaluated by a colorimetric COX (ovine) inhibitor screening method. Vero cells were used to assess the toxicity against the normal cells, and calculate the selectivity index. COX inhibitory activity results were evaluated and confirmed by molecular docking experiments. In the in vivo approach, analgesic activity was assessed by acetic acid-induced abdominal writhing and formalin tests. Croton oil-induced ear edema in mice and carrageenan-induced rat paw edema in rats were used to evaluate anti-inflammatory activity. Pain tests were carried out on male Swiss mice (25-35 g). Male Wistar rats (160-200 g) were used for the carrageenan test.
Cycloart-23-ene-3β,25-diol showedin vitro cyclooxygenase 1 and 2 inhibitory activities with more selectivity for COX-2. Molecular docking by predicting binding energies in COX protein receptors confirmed in vitro COX inhibitory results, and determined the best position for ligand in COX receptors along with its residue interactions in receptor pockets, which must be considered for designing of their inhibitors. In the in vivo studies, cycloartane inhibited significantly acetic acid-induced abdominal contractions and formalin-induced licking behavior at a dose of 200 mg/kg. The same dose reduced croton oil ear edema in mice and carrageenan-induced paw edema in rats.
Therefore, according to these findings, cycloart-23-ene-3beta,25-diol showed promising analgesic and anti-inflammatory effects with low toxicity against normal cells and can be suggested as a template lead for designing anti-inflammatory compounds with good selectivity index, and potency for COX-2 inhibitory activity.
大戟属是开花植物的一个大属。在伊朗，该科的一些植物已被用于治疗炎症性疾病，并缓解背痛。棘叶大戟是环阿尔塔-23-烯-3β，25-二醇的丰富来源。环阿尔塔烷结构是植物甾体合成的起始材料，本研究的目的是证明从棘叶大戟中分离出的环阿尔塔烷化合物的 COX 抑制活性、分子对接和体内抗炎活性。
用丙酮-氯仿提取植物材料，并进行柱层析进行分离。根据初步的 H-NMR 光谱，选择环阿尔塔烷部分并通过重复循环 HPLC 系统进行纯化。通过 H 和 C-NMR、HPTLC 和质谱确定化合物的结构和纯度。用比色 COX（绵羊）抑制剂筛选法评价测试化合物对 COX-1 和 COX-2 的抑制活性。用 Vero 细胞评估对正常细胞的毒性，并计算选择性指数。通过分子对接实验评估和确认 COX 抑制活性结果。在体内方法中，通过醋酸诱导的腹部扭曲和福氏试验评估镇痛活性。用巴豆油诱导的小鼠耳肿胀和角叉菜胶诱导的大鼠足肿胀来评价抗炎活性。在雄性瑞士小鼠（25-35g）上进行疼痛测试。用雄性 Wistar 大鼠（160-200g）进行角叉菜胶试验。
环阿尔塔-23-烯-3β，25-二醇在体外对环氧化酶 1 和 2 具有抑制活性，对 COX-2 的选择性更高。通过预测 COX 蛋白受体中结合能的分子对接证实了体外 COX 抑制结果，并确定了配体在 COX 受体中的最佳位置及其在受体口袋中的残基相互作用，这对于设计它们的抑制剂必须考虑。在体内研究中，环阿尔塔烷在 200mg/kg 剂量下显著抑制醋酸诱导的腹部收缩和福氏诱导的舔行为。相同剂量可减少巴豆油诱导的小鼠耳肿胀和角叉菜胶诱导的大鼠足肿胀。
因此，根据这些发现，环阿尔塔-23-烯-3β，25-二醇表现出有希望的镇痛和抗炎作用，对正常细胞的毒性低，可作为设计具有良好选择性指数和 COX-2 抑制活性的抗炎化合物的模板先导。
