光诱导白藜芦醇与眼镜蛇神经毒素聚合和协同镇痛作用

Binding of resveratrol to cobra neurotoxin induced by illumination and their synergistic analgesic effects

目的:研究白藜芦醇与眼镜蛇神经毒素在生理pH条件下的经光诱发产生的相互作用及其对镇痛的影响。方法:采用紫外可见光谱和荧光光谱法扫描不同白藜芦醇浓度下眼镜蛇神经毒素(NT)在pH7.4磷酸缓冲液中的光谱,测定365 nm光照射白藜芦醇后的NT的荧光光谱。采用醋酸扭体法和热板法考察在白藜芦醇和NT联合用药并经尾静脉光照后对小鼠的镇痛效果。结果:紫外可见光谱和荧光光谱峰形发生了变化,紫外可见光吸收增强,荧光猝灭,光照加剧了猝灭效应,说明NT与白藜芦醇产生了聚合作用。其结合常数Ka为5.12×105 L·mol-1,结合位点数n为1,结合距离R为3.40 nm,故易发生非辐射能量转移。白藜芦醇和NT联合给药并光照后,小鼠镇痛效果较单独给药或联合给药但非光照组增强。结论:白藜芦醇在光诱导下活化与NT聚合,产生了协同镇痛作用。

OBJECTIVE To reveal the interaction of resveratroi with cobra neurotoxin （NT） induced by illumination in phys- iological pH condition, and their effects on pain inhibitiorL METHODS Ultra-violet spectra and fluorescence spectra of NT in pH 7. 4 phosphate buffer mixed with different concentration of resveratroi were determined under illumination by laser at 365nm. Analgesic effects were measured by acetic acid writhing method and hot plate test in mice after drug combination of res- veratrol and NT with tail vein vascular illumination. RESULTS Curve shape in spectra was changed, ultra-violet absorption was enhanced and fluorescence was quenched. Illumination of laser at 365 nm intensified the quenching. It showed that resvera- trol was bound to NT. The binding constants Ka were 5.12 ×105L·mol-1. Number of binding sites n was 1; the binding dis- tance R was 3.40 nm, and that easily leaded to non radiation energy transfer. Analgesic effects were stronger in the group of drug combination with illumination than others. CONCLUSION Resveratrol is activated by laser, bound to NT and that leads to synergistic analgesic effects.