Department of Biochemistry and Pharmacology, Federal University of Piaui, Teresina-PI, Brazil.
Pharm Biol. 2013 Oct;51(10):1243-8. doi: 10.3109/13880209.2013.786096. Epub 2013 Jul 11.
CONTEXT. Cenostigma macrophyllum Tul. var. acuminata Teles Freire (Leguminosae- Caesalpinioideae) is popularly known as "caneleiro". Previous studies showed antioxidant action and analgesic effects of the ethanol extract from the leaves of C. macrophyllum. The phytochemical evaluation of the stem bark revealed the presence of antinociceptive compounds.
To investigate the antinociceptive actions of the ethanol extract and ethyl acetate fraction from C. macrophyllum stem bark in streptozotocin (STZ)-induced diabetic rats and the involvement of opioid and nitrergic mechanisms.
STZ-rats received the ethanol extract (E.EtOH 200 and 300 mg/kg, p.o.) during 5 weeks. In acute experiments, untreated diabetic rats were treated with the ethyl acetate fraction (F.EtOAc 250 and 500 mg/kg, p.o.), on the 28th day of diabetes induction when the opioid and nitrergic mechanisms were investigated. The mechanical nociceptive threshold (MNT) was determined by application of von Frey filaments.
Data show that STZ-induced diabetic rats developed a significant tactile allodynia during 5 weeks. Diabetic rats that received E.EtOH (200 and 300 mg/kg) and F.EtOAc (250 and 500 mg/kg) had a pain threshold higher than those in the STZ-vehicle group. F.EtOAc effects were inhibited by pretreatment with naloxone and were not influenced by .-arginine.
The results suggest that the ethanol extract and ethyl acetate fraction of C. macrophyllum presented antinociceptive activity. Thus, F.EtOAc may be exerting its effect by affecting the opioid system, but nitrergic mechanisms are not detectable. The observed activity may be due to its gallic acid, lupeol and bergenin content.
研究毛瓣山蚂蝗茎皮乙醇提取物和乙酸乙酯部位在链脲佐菌素（STZ）诱导的糖尿病大鼠中的镇痛作用及阿片和氮能机制的参与。
STZ 大鼠在 5 周内接受乙醇提取物（E.EtOH200 和 300mg/kg，po）治疗。在急性实验中，未经处理的糖尿病大鼠在第 28 天糖尿病诱导时用乙酸乙酯部位（F.EtOAc250 和 500mg/kg，po）治疗，研究阿片和氮能机制。机械性痛觉阈值（MNT）通过 von Frey 丝测定。
数据显示，STZ 诱导的糖尿病大鼠在 5 周内发生明显的触觉过敏。接受 E.EtOH（200 和 300mg/kg）和 F.EtOAc（250 和 500mg/kg）的糖尿病大鼠的痛阈高于 STZ-载体组。F.EtOAc 的作用被纳洛酮预处理抑制，不受.-精氨酸影响。
结果表明，毛瓣山蚂蝗的乙醇提取物和乙酸乙酯部位具有镇痛活性。因此，F.EtOAc 可能通过影响阿片系统发挥其作用，但氮能机制不可检测。观察到的活性可能与其没食子酸、羽扇豆醇和 Bergenin 含量有关。
