Nisar Muhammad, Ali Sajid, Muhammad Naveed, Gillani Syed N, Shah Muhmmad R, Khan Haroon, Maione Francesco
Institute of Chemical Sciences, University of Peshawar, Peshawar, Pakistan.
Department of Pharmacy, Abdul Wali Khan University, Mardan, Pakistan.
Toxicol Ind Health. 2016 Jul;32(7):1254-9. doi: 10.1177/0748233714555391. Epub 2014 Dec 11.
Rhododendron arboreum Smith. (Ericaceae), an evergreen small tree, is one of the 1000 species that belongs to genus Rhododendron distributed worldwide. In folk medicine, as various parts of this plant exhibit medicinal properties, it is used in the treatment of different ailments.The present study was designed to evaluate the potential anti-inflammatory and antinociceptive effects of methanolic extract of R. arboreum bark, followed by activity-guided fractionation of n-hexane, n-butanol, chloroform, ethyl acetate and aqueous fractions.The ethyl acetate fraction (200 mg/kg i.p.) showed the maximum analgesic effect (82%) in acetic acid-induced writhing, followed, to a less extent, by crude extract and chloroform fraction both at a dose of 200 mg/kg i.p. (65.09% and 67.89%, respectively). In carrageenan-induced mouse paw oedema, the crude extract and its related fractions displayed in a dose-dependent manner (50-200 mg/kg i.p.) an anti-inflammatory activity for all time-courses (1-5 hrs). For the active extract/fractions (200 mg/kg i.p.), the maximum effect was observed 5 h after carrageenan injection. These evidences were also supported by in vitro lipoxygenase inhibitory properties. In conclusion, R. arboreum crude methanolic extract and its fractions exhibited anti-inflammatory and antinociceptive effects. For these reasons, this plant could be a promising source of new compounds for the management of pain and inflammatory diseases.
树形杜鹃（杜鹃花科），一种常绿小乔木，是全球分布的杜鹃花属1000个物种之一。在民间医学中，由于该植物的各个部位都具有药用特性，因此被用于治疗各种疾病。本研究旨在评估树形杜鹃树皮甲醇提取物的潜在抗炎和抗伤害感受作用，随后对正己烷、正丁醇、氯仿、乙酸乙酯和水相部分进行活性导向分级分离。乙酸乙酯部分（200mg/kg腹腔注射）在醋酸诱导的扭体实验中显示出最大的镇痛效果（82%），其次是粗提取物和氯仿部分，腹腔注射剂量均为200mg/kg（分别为65.09%和67.89%）。在角叉菜胶诱导的小鼠足爪水肿实验中，粗提取物及其相关部分在所有时间点（1-5小时）均以剂量依赖性方式（50-200mg/kg腹腔注射）显示出抗炎活性。对于活性提取物/部分（200mg/kg腹腔注射），在注射角叉菜胶后5小时观察到最大效果。这些证据也得到了体外脂氧合酶抑制特性的支持。总之，树形杜鹃粗甲醇提取物及其部分表现出抗炎和抗伤害感受作用。基于这些原因，这种植物可能是用于管理疼痛和炎症性疾病的新化合物的有希望的来源。
