Department of Pharmacology and Therapeutics, Kogi State University, Anyigba, Nigeria.
Department of Pharmacology and Therapeutics, Ahmadu Bello University, Zaria, Nigeria.
J Ethnopharmacol. 2017 Mar 6;199:323-327. doi: 10.1016/j.jep.2016.12.052. Epub 2017 Feb 4.
Preparations of Olax subscorpioidea have been used traditionally for the management of pains, inflammatory diseases, yellow fever, cancer and rheumatism. Previously, the analgesic activity of its leaf extract have been reported. Furthermore, an analgesic assay guided fractionation showed that the butanol soluble fraction is the most active. However, the mechanism of this activity remains to be elucidated. This present study investigated the possible pharmacological mechanisms involved in the analgesic activity of the butanol leaf fraction of Olax subscorpioidea (BFOS) using the acetic acid induced writhing test in mice.
Animals were orally administered distilled water (10ml/kg), BFOS (1,000mg/kg) and morphine (10mg/kg) 60minutes before i.p administration of acetic acid and the resulting writhing were counted for 10minutes. To establish the possible mechanism(s) of action of BFOS, separate group of animals were pretreated with naloxone (2mg/kg, i.p), prazosin (1mg/kg, i.p), yohimbine (1mg/kg, i.p), propranolol (20mg/kg, i.p), metergoline (2mg/kg, i.p), glibenclamide (5mg/kg, i.p) and l-arginine (50mg/kg, i.p) 15minutes before BFOS.
BFOS and morphine showed marked analgesic activities (p<0.001); the pretreatment of animals with naloxone, metergoline and l-arginine significantly (p<0.05 and p<0.001) reduced the analgesic activity of BFOS; however, pretreatment with prazosin, yohimbine, propranolol and glinbenclamide showed no effect on its analgesic activity.
Results obtained in this study suggest the involvement of opioidergic, serotonergic and nitric oxide-l-arginine pathways in the analgesic effect of butanol leaf fraction of Olax subscorpioidea.
Olax subscorpioidea 的制剂已被传统上用于治疗疼痛、炎症性疾病、黄热病、癌症和风湿病。此前，已有研究报道其叶提取物具有镇痛活性。此外，镇痛测定导向分离表明，正丁醇可溶性部分是最活跃的。然而，这种活性的机制仍有待阐明。本研究采用醋酸诱导扭体试验，研究 Olax subscorpioidea 正丁醇叶部分（BFOS）的镇痛活性的可能药理学机制。
动物在腹腔注射醋酸前 60 分钟分别口服蒸馏水（10ml/kg）、BFOS（1000mg/kg）和吗啡（10mg/kg），并在 10 分钟内计数扭体反应。为了确定 BFOS 的作用机制，另一组动物在 BFOS 预处理前 15 分钟分别用纳洛酮（2mg/kg，腹腔注射）、哌唑嗪（1mg/kg，腹腔注射）、育亨宾（1mg/kg，腹腔注射）、普萘洛尔（20mg/kg，腹腔注射）、麦角乙脲（2mg/kg，腹腔注射）、格列本脲（5mg/kg，腹腔注射）和 l-精氨酸（50mg/kg，腹腔注射）预处理。
BFOS 和吗啡表现出明显的镇痛活性（p<0.001）；纳洛酮、麦角乙脲和 l-精氨酸预处理的动物显著（p<0.05 和 p<0.001）降低了 BFOS 的镇痛活性；然而，哌唑嗪、育亨宾、普萘洛尔和格列本脲预处理对其镇痛活性无影响。
本研究结果表明，Olax subscorpioidea 正丁醇叶部分的镇痛作用涉及阿片能、5-羟色胺能和一氧化氮-l-精氨酸途径。
