千里光超微粉的镇痛机制研究

Study on Analgesic Mechanism of Senecio scandens Ultrafine Powder

为研究中草药千里光(Senecio scandens Buch.-Ham)超微粉的镇痛机制,为千里光镇痛剂的开发利用提供参考依据,本研究以6周龄昆明小鼠为试验动物,制备千里光超微粉混悬液,设千里光超微粉高(360mg/kg体重)、中(180mg/kg体重)、低(90mg/kg体重)剂量组,以灌胃方式连续给药7d后进行后续相关试验,通过甲醛致痛模型和热浴甩尾法验证其镇痛作用并用以区分中枢镇痛和外周镇痛作用,通过纳洛酮颉颃试验、利血平颉颃试验及对小鼠血清和脑组织中五羟色胺(5-HT)和一氧化氮(NO)浓度的检测等方法来探究其中枢镇痛和外周镇痛机制。结果显示,千里光超微粉能提高甲醛致痛模型和热浴甩尾法中小鼠的痛阈值,且呈剂量-效应关系;纳洛酮和利血平分别作为阿片受体阻断剂和抗去甲肾上腺素能神经末梢药,可部分颉颃千里光超微粉的镇痛作用;千里光超微粉可显著提高脑组织5-HT的浓度,降低血清中5-HT的浓度(P<0.05),但对于脑组织和血清中NO的浓度调节效果不明显。结果表明,千里光超微粉具有中枢性和外周性镇痛作用,其镇痛途径与阿片受体存在一定关系,可通过抑制囊泡膜对递质去甲肾上腺素(NE)的主动摄取过程而间接发挥镇痛作用;还可通过升高中枢NO和5-HT的浓度及降低外周NO和5-HT的浓度来发挥其镇痛作用,但对于NO的浓度调节效果不明显。

To investigate the analgesic mechanism of Senecio scandens ultrafine powder,and provide theoretical basis and reference for the S.scandens analgesic.In this study,6-week-old Kunming mice were used as experimental animals.The suspension of S.scandens ultrafine powder was prepared,and S.scandens ultrafine powder was administered at high(360 mg/kg·BW),medium(180 mg/kg·BW)and low(90 mg/kg·BW)dose groups,after 7 days of continuous administration by gavage,follow-up related experiments were carried out.The analgesic effect was verified by formaldehyde-induced pain model and hot-water tail-flick,and it was used to distinguish central analgesia and peripheral analgesia.The analgesic mechanism of S.scandens ultrafine powder was investigated by naloxone antagonistic test,reserpine antagonistic test,and detecting the concentrations of serotonin(5-HT)and nitric oxide(NO)in serum and brain tissue.The experiment proved that S.scandens ultrafine powder could increase the pain threshold of formaldehyde-induced pain model and hot-water tail-flick in a dose-dependent manner;Naloxone and reserpine as opioid receptor blockers and anti-noradrenergic nerve terminal,respectively,could partially antagonize the analgesia effect of S.scandens ultrafine powder.S.scandens ultrafine powder could significantly increase the content of 5-HT in brain tissue and reduce the content of 5-HT in serum(P<0.05),but was not significant for NO.S.scandens ultrafine powder had central and peripheral analgesic effects in a dose-dependent manner.The analgesic pathway was related to opioid receptors and NE;It also exerted its analgesic effect by increasing the contents of central NO and 5-HT,and decreasing the contents of peripheral NO and 5-HT,but the effect of regulating NO content was not obvious.