Pharmacognosy Department, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt.
Pharmacognosy Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt; Center for Drug Discovery Research and Development, Ain Shams University, Egypt.
J Ethnopharmacol. 2021 May 10;271:113767. doi: 10.1016/j.jep.2020.113767. Epub 2021 Jan 12.
Pulicaria incisa sub. candolleana E. Gamal-Eldin (Asteraceae) was traditionally used by Bedouins as a refreshing tea and as hypoglycemic, in gastrointestinal ailments, sinusitis and headache. Recently a great correlation has been established between liver cirrhosis and gastrointestinal dysfunction reflected by abdominal bloating, pain, diarrhea, constipation, besides decreased food intake. So far, the hepatoprotective effect of P. incisa sub. candolleana E. Gamal-Eldin was not studied before although other Pulicaria species have previously shown hepatoprotective and antioxidant effects.
In this study, we aimed to identify the phytochemical constituents of the P. incisa sub. candolleana E. Gamal-Eldin hydroethanolic extract (PICE), as well as to evaluate the hepatoprotective, anti-inflammatory and antioxidant activities in methotrexate (MTX)- intoxicated rats. Besides, the molecular interaction between the isolated compounds and cyclooxygenase-2 (COX-2) and phospholipase 2 (PLA-2) were assessed by in-silico screening.
The main phytoconstituents were characterized using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Vacuum liquid chromatography (VLC) aided by preparative high-performance liquid chromatography (HPLC) were also used to isolate the major phenolics from the hydroethanolic extract. Their structures were elucidated using different spectroscopic analysis methods, including 1D and 2D nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI/MS). The hepatoprotective activity of three doses (100, 250, 500 mg/kg) of PICE in MTX-intoxicated rats was assessed and compared to silymarin as a standard. Additionally, in silico docking study on cyclooxygenase-2 (COX-2) and phospholipase 2 (PLA-2) was performed to justify the anti-inflammatory activity of the isolated compounds.
Thirteen compounds were tentatively identified, including flavonoids and phenolic acids. Four main isolated compounds were identified as, eugenol-1-O-β-glucoside, 5-O-caffeoylquinic acid, 3, 5-di-O-caffeoylquinic acid and quercetin-3-O-β-glucoside. Treatment of MTX-intoxicated rats with the 250 mg/kg extract reversed the altered levels of biochemical markers of liver damage, ameliorated the oxidant status and reduced the inflammatory mediators, similar to treatment with silymarin. Quercetin-3-O-β-glucoside showed the best docking energy score of -19.12 kcal/mol against COX-2, forming four binding interactions with residues Leu 353, Arg 121, Tyr 356 and Ala 528, followed by 3,5-di-O-caffeoylquinic acid (-18.01 kcal/mol).
This study reveals P. incisa sub. candolleana as a rich source of phenolics including flavonoids, supporting its anti-inflammatory and hepatoprotective effects and suggesting its usage as a promising candidate in inflammatory conditions.
Pulicaria incisa sub. candolleana E. Gamal-Eldin（菊科）被贝都因人传统上用作清爽的茶，具有降血糖、治疗胃肠道疾病、鼻窦炎和头痛的功效。最近，人们发现肝硬化与胃肠道功能障碍之间存在密切关联，表现为腹胀、疼痛、腹泻、便秘和食欲下降。尽管其他 Pulicaria 物种已显示出保肝和抗氧化作用，但迄今为止，尚未对 P. incisa sub. candolleana E. Gamal-Eldin 的保肝作用进行研究。
本研究旨在鉴定 P. incisa sub. candolleana E. Gamal-Eldin 水醇提取物（PICE）中的植物化学成分，并评估其在甲氨蝶呤（MTX）中毒大鼠中的保肝、抗炎和抗氧化活性。此外，通过计算机筛选评估分离化合物与环氧化酶-2（COX-2）和磷脂酶 2（PLA-2）之间的分子相互作用。
使用液相色谱-串联质谱（LC-MS-MS）对主要植物成分进行鉴定。真空液相色谱（VLC）辅以制备高效液相色谱（HPLC）也用于从水醇提取物中分离主要酚类化合物。使用不同的光谱分析方法，包括一维和二维核磁共振（NMR）和电喷雾电离质谱（ESI/MS），对其结构进行了阐明。评估了 PICE 在 MTX 中毒大鼠中的三个剂量（100、250、500mg/kg）的保肝活性，并与水飞蓟素进行了比较。此外，还对 COX-2 和 PLA-2 进行了计算机对接研究，以证明分离化合物的抗炎活性。
共鉴定出 13 种化合物，包括黄酮类和酚酸类化合物。分离出的 4 种主要化合物分别为丁香酚-1-O-β-葡萄糖苷、5-O-咖啡酰奎宁酸、3,5-二-O-咖啡酰奎宁酸和槲皮素-3-O-β-葡萄糖苷。用 250mg/kg 提取物治疗 MTX 中毒大鼠可逆转肝损伤的生化标志物水平的改变，改善氧化状态并减少炎症介质，与水飞蓟素治疗效果相似。槲皮素-3-O-β-葡萄糖苷对 COX-2 的结合能评分为-19.12kcal/mol，与残基 Leu 353、Arg 121、Tyr 356 和 Ala 528 形成四个结合相互作用，其次是 3,5-二-O-咖啡酰奎宁酸（-18.01kcal/mol）。
本研究揭示了 P. incisa sub. candolleana 是一种富含类黄酮的酚类化合物的丰富来源，支持其抗炎和保肝作用，并表明其在炎症条件下具有作为有前途的候选物的用途。
