Sajid Moniba, Khan Muhammad Rashid, Shah Sayed Afzal, Majid Muhammad, Ismail Hammad, Maryam Sonia, Batool Riffat, Younis Tahira
Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
J Ethnopharmacol. 2017 Feb 23;198:407-416. doi: 10.1016/j.jep.2017.01.041. Epub 2017 Jan 21.
Stem bark of Alnus nitida (Spach) Endl. (family Betulaceae) is used by local communities in northern areas of Pakistan as a remedy for swelling, injuries and pain. However no pharmacological study of this plant has been reported to confirm these activities. In this study anti-inflammatory and analgesic effect of A. nitida stem bark have been evaluated.
Powder of the stem bark of A. nitida was extracted with methanol (ANBM) and partitioned in escalating polarity to get the n-hexane (ANBH), chloroform (ANBC), ethyl acetate (ANBE) and the residual soluble aqueous (ANBA) fractions. The methanol extract and derived fractions were evaluated for anti-inflammatory activity by using in vitro heat induced albumin denaturation assay and various in vivo assays; carrageenan-induced hind paw edema method, Freunds' complete adjuvant induced arthritis, histamine induced paw edema and xylene induced ear edema in Sprague Dawley rat. The extracts/fractions were also evaluated for analgesic effects by using hot plate analgesic test and acetic acid induced writhing test in rat. The ANBM composition was analyzed by HPLC-DAD and GC-MS analysis.
Results of heat induced albumin denaturation activity indicated that among the extract/fractions ANBC at concentration range of 100-500µg/ml remarkably protected the heat induced albumin denaturation. The pretreatment with ANBC significantly reduced the carrageenan induced edema with 90.81±1.6% after 4h, comparing with 86.63±3.42% reduction produced by the reference drug diclofenac potassium. Histopathological alterations of the gastric and hind paw were decreased with the extract/fractions. Furthermore, anti-inflammatory effects of ANBC were evident in Freunds' complete adjuvant induced arthritis, histamine induced paw edema and xylene induced ear edema. The latency time in hot plate analgesic assay with ANBC (61.59±0.38%) after 90min was comparable to standard drug morphine (69.31±2.67%) and aspirin (67.24±2.08%). Similarly ANBC significantly (p<0.01) inhibited the pain sensation in acetic acid induced writhing test in rat. HPLC-DAD analysis of ANBM indicated the presence of gallic acid, catechin and rutin while the GC-MS analysis of ANBM indicated the presence of 30 compounds predominantly of neophytadiene, 3,7,11,15 tetramethyl-2-hexadecen-1-ol, phytol, vitamin E and linalool.
The results of this study suggested that the presence of polyphenols, sterols, terpenoids and other constituents might contributed towards the anti-inflammatory and analgesic activities of the crude methanol extract of A. nitida bark and its derived fractions. This study endorsed the folklore use of A. nitida bark for inflammation related disorders.
亮叶桤木（桦木科）的茎皮被巴基斯坦北部地区的当地社区用作治疗肿胀、损伤和疼痛的药物。然而，尚未有关于该植物的药理学研究报告来证实这些活性。在本研究中，对亮叶桤木茎皮的抗炎和镇痛作用进行了评估。
亮叶桤木茎皮粉末用甲醇提取（ANBM），并按极性递增进行分配，得到正己烷（ANBH）、氯仿（ANBC）、乙酸乙酯（ANBE）和残留的可溶性水相（ANBA）部分。通过体外热诱导白蛋白变性试验和各种体内试验评估甲醇提取物及其衍生部分的抗炎活性；在Sprague Dawley大鼠中进行角叉菜胶诱导的后爪水肿法、弗氏完全佐剂诱导的关节炎、组胺诱导的爪水肿和二甲苯诱导的耳水肿试验。提取物/部分还通过热板镇痛试验和大鼠醋酸诱导扭体试验评估镇痛效果。通过HPLC-DAD和GC-MS分析对ANBM成分进行分析。
热诱导白蛋白变性活性结果表明，在提取物/部分中，浓度范围为100-500μg/ml的ANBC能显著保护热诱导的白蛋白变性。与参考药物双氯芬酸钾产生的86.63±3.42%的降低相比，ANBC预处理在4小时后显著降低了角叉菜胶诱导的水肿，降低率为90.81±1.6%。提取物/部分减轻了胃和后爪的组织病理学改变。此外，ANBC在弗氏完全佐剂诱导的关节炎、组胺诱导的爪水肿和二甲苯诱导的耳水肿中具有明显的抗炎作用。90分钟后，ANBC在热板镇痛试验中的潜伏期（61.59±0.38%）与标准药物吗啡（69.31±2.67%）和阿司匹林（67.24±2.08%）相当。同样，ANBC在大鼠醋酸诱导扭体试验中显著（p<0.01）抑制疼痛感觉。ANBM的HPLC-DAD分析表明存在没食子酸、儿茶素和芦丁，而ANBM的GC-MS分析表明存在30种化合物，主要是新植二烯、3,7,11,15-四甲基-2-十六碳烯-1-醇、叶绿醇、维生素E和芳樟醇。
本研究结果表明，多酚、甾醇、萜类化合物和其他成分的存在可能有助于亮叶桤木树皮粗甲醇提取物及其衍生部分的抗炎和镇痛活性。本研究支持了亮叶桤木树皮在民间用于治疗炎症相关疾病的用途。
