Department of Anesthesiology, Women's and Children's Hospital Affiliated to Qingdao University, Qingdao 266034, China.
2 Yangzhou University, Yangzhou 225009, China.
J Tradit Chin Med. 2023 Oct;43(5):915-924. doi: 10.19852/j.cnki.jtcm.20230802.006.
To evaluate the effect of berberine on morphine analgesia, tolerance, and hyperalgesia.
Morphine-induced acute tolerance model: mice received intraperitoneal berberine at doses of 2.5, 5.0, and 10 mg/kg; 30 min later, subcutaneous morphine 10 mg/kg was injected every hour for nine continuous h. Morphine 10 mg/kg alone was administered at 24 and 48 h. Morphine-induced chronic tolerance model: mice received intraperitoneal berberine 2.5, 5.0, and 10 mg/kg; 30 min later, 10 mg/kg morphine was injected subcutaneously for eight consecutive days. On the ninth day, morphine 10 mg/kg was given alone. Morphine-induced established tolerance model: mice were injected subcutaneously with morphine 10 mg/kg once a day for eight consecutive days. Berberine 2.5 mg/kg was administered on day one, four, and seven and morphine 10 mg/kg alone on day nine. The baseline latency (T0) and post-treatment latency (T1) were determined by the hot plate test, and the maximum possible analgesic effect (MPAE) was calculated. Nitric oxide synthase (NOS) activity and nitric oxide (NO) content in the spinal cord were measured by spectrophotometer. Verification of berberine analgesic effect by blocking N-methyl-D-aspartate (NMDA) receptor: HT-22 and HEK-293 cells transfected with NMDA plasmid were randomly divided into five groups: control group, NMDA group, berberine low-dose, medium-dose, and high-dose groups (5, 10, 20 μmol/L, respectively). Except for the control group, cells were treated with NMDA (HT-22 cells: 20 mmol/L; HEK-293 cells: 50 μmol/L). After 24 h, cell viability was detected by cell counting kit-8. The molecular mechanism between berberine and the NMDA receptor was studied by molecular docking.
Berberine 2.5 and 5.0 mg/kg could prolong the analgesic time of morphine. In acute and chronic morphine tolerance models, berberine could inhibit the decrease of MPAE and baseline latency (0.05). In the established tolerance model, berberine could rapidly reverse the decreased MPAE (0.05). The combination of berberine and morphine on day one could effectively inhibit the morphine-induced increase of NOS activity and NO content in the spinal cord (0.05). Berberine significantly increased the cell viability of NMDA-induced nerve injury in HT-22 and HEK-293 cells (0.05). Molecular docking showed that berberine binds to the receptor pocket of NMDA.
Berberine could effectively enhance and prolong the duration of morphine analgesia and inhibit the development of morphine-induced tolerance and hyperalgesia. Furthermore, berberine has a certain neuroprotective effect, which may be related to the inhibition of NMDA activity.
评价小檗碱对吗啡镇痛、耐受和痛觉过敏的影响。
吗啡诱导的急性耐受模型：小鼠分别腹腔注射小檗碱 2.5、5.0 和 10 mg/kg；30 min 后，每隔 1 h 皮下注射吗啡 10 mg/kg，连续 9 小时。在 24 和 48 h 时单独给予吗啡 10 mg/kg。吗啡诱导的慢性耐受模型：小鼠分别腹腔注射小檗碱 2.5、5.0 和 10 mg/kg；30 min 后，连续 8 天皮下注射吗啡 10 mg/kg。第 9 天，单独给予吗啡 10 mg/kg。吗啡诱导的已建立的耐受模型：小鼠连续 8 天每天皮下注射吗啡 10 mg/kg。在第 1、4 和 7 天给予小檗碱 2.5 mg/kg，第 9 天单独给予吗啡 10 mg/kg。采用热板试验测定基线潜伏期（T0）和治疗后潜伏期（T1），计算最大可能镇痛效应（MPAE）。用分光光度计测定脊髓中一氧化氮合酶（NOS）活性和一氧化氮（NO）含量。通过阻断 N-甲基-D-天冬氨酸（NMDA）受体验证小檗碱的镇痛作用：将转染 NMDA 质粒的 HT-22 和 HEK-293 细胞随机分为五组：对照组、NMDA 组、小檗碱低、中、高剂量组（分别为 5、10、20 μmol/L）。除对照组外，NMDA（HT-22 细胞：20 mmol/L；HEK-293 细胞：50 μmol/L）处理细胞 24 h 后，用细胞计数试剂盒-8 检测细胞活力。通过分子对接研究小檗碱与 NMDA 受体之间的分子机制。
小檗碱 2.5 和 5.0 mg/kg 可延长吗啡的镇痛时间。在急性和慢性吗啡耐受模型中，小檗碱可抑制 MPAE 和基线潜伏期的降低（0.05）。在已建立的耐受模型中，小檗碱可迅速逆转 MPAE 的降低（0.05）。第 1 天小檗碱和吗啡联合使用可有效抑制吗啡诱导的脊髓 NOS 活性和 NO 含量增加（0.05）。小檗碱可显著增加 NMDA 诱导的 HT-22 和 HEK-293 细胞神经损伤的细胞活力（0.05）。分子对接显示，小檗碱与 NMDA 的受体口袋结合。
小檗碱可有效增强和延长吗啡镇痛作用，并抑制吗啡诱导的耐受和痛觉过敏的发展。此外，小檗碱具有一定的神经保护作用，这可能与抑制 NMDA 活性有关。
