目的 以香菇多糖为稳定剂制备土木香内酯纳米晶（Len-Ala-NCs），考察其口服相对生物利用度及对H1N1流感病毒感染小鼠的治疗作用。方法 采用高速剪切联合高压均质法制备Len-Ala-NCs，选取香菇多糖质量分数、均质压力、均质次数为主要影响因素，通过单因素试验结合Box-Behnken设计-响应面法（BBD-RSM）优化处方工艺，测定其粒径、多分散系数（PDI）及Zeta电位；采用扫描电镜（SEM）观察微观形貌，X射线粉末衍射法（XRPD）分析晶型，饱和溶剂法测定溶解度，透析法考察释药行为。ig给予SD大鼠土木香内酯及Len-Ala-NCs (均以土木香内酯计，100 mg·kg^-1)，比较药动学特征并计算口服相对生物利用度。通过滴鼻接种H1N1病毒构建小鼠流感感染模型，考察Len-Ala-NCs对模型小鼠生存率和肺组织H1N1流感病毒M2 mRNA相对表达量的影响。采用HE染色法观察肺组织病理学变化。结果 Len-Ala-NCs的最佳处方工艺为香菇多糖质量分数0.26%、均质压力85.00 MPa、均质次数8次。所得纳米晶平均粒径为（214.62±3.83）nm,PDI为0.115±0.007,Zeta电位为（-13.80±0.93）m V，微观形貌呈椭圆形；土木香内酯在Len-Ala-NCs中结晶度显著降低。LenAla-NCs可显著提高土木香内酯在pH 2.0、6.8磷酸盐缓冲液及水中的溶解度，12 h累积释放度达88.61%。与土木香内酯相比，Len-Ala-NCs的达峰时间(t_max)提前至（0.52±0.16）h，达峰浓度(C_max)增至（892.15±113.61）ng·mL^-1，口服相对生物利用度提高至3.99倍。Len-Ala-NCs (100 mg·kg^-1)可显著提高H1N1感染模型小鼠的存活率，且对肺组织M2 mRNA相对表达量的降低效果显著优于土木香内酯(100 mg·kg^-1)（P<0.01），与磷酸奥司他韦组比较无统计学差异（P>0.05）。HE染色结果显示，Len-Ala-NCs (100 mg·kg^-1)极大缓解了肺组织淤血及炎症反应，治疗效果趋近于磷酸奥司他韦组及对照组。结论 Len-Ala-NCs可显著提高土木香内酯的口服相对生物利用度，并增强对流感病毒感染小鼠的治疗作用。

Objective Lentinan-alantolactone nanocrystals（Len-Ala-NCs） was prepared using lentinan as stabilizer, and investigated its relative oral bioavailability and therapeutic effect of H1N1 influenza virus infection in mice. Methods High-speed shear combined with high-pressure homogenization method were employed to prepare Len-Ala-NCs. Lentinan concentration, homogenization power and times were selected as main influencing factors, single factor experiments and Box-Behnken response surface design method（BBD-RSM） was used to optimize the optimal prescription process of Len-Ala-NCs. Particle size, polymer dispersity index（PDI） value and Zeta potential of Len-Ala-NCs were determined. Microscopic morphology of Len-Ala-NCs was observed by scanning electron microscope（SEM）, crystal form was analyzed by X-ray powder diffraction（XRPD）, solubility was determined by saturated solvent method and drug release behavior was investigated by dialysis method. Alantolactone and Len-Ala-NCs were administered orally(100 mg·kg^-1, calculated by alantolactone), pharmacokinetic characteristic was compared and the oral relative bioavailability was calculated. The influenza infection model in mice was constructed by intranasal inoculation of H1N1 virus, and studied the effects of Len-Ala-NCs on the survival rate and relative expression level of M2 mRNA of H1N1 influenza virus in lung tissue. The pathology changes in lung tissue were observed by HE staining method. Results Optimal prescription process of Len-Ala-NCs: Lentinan concentration was 0.26%, homogenization power was 85.00 MPa and homogenization times was 8 times. Particle size, PDI and Zeta potential of Len-Ala-NCs were（214.62 ±3.83） nm, 0.115 ±0.007 and（-13.80 ±0.93） mV, respectively. Morphology of Len-Ala-NCs were ellipsoidal nanoparticles, and the crystallinity of alantolactone decreased significantly in Len-Ala-NCs. Len-Ala-NCs greatly improved the solubility of alantolactone in pH 2.0, 6.8 phosphate buffer and water, and the cumulative release rate reached 88.61% in 12 h. The t_max of Len-Ala-NCs was advanced to（0.52 ±0.16） h, C_max was enhanced to（892.15 ±113.61） ng·mL^-1, and relative oral bioavailability was enhanced to 3.99 times. Len-Ala-NCs(100 mg·kg^-1) effectively improved the survival rate of H1N1-infected mice and reduced H1N1 viral load in lung tissue, its effect was significantly better than that of alantolactone(100 mg·kg^-1), and there was no statistically significant difference with oseltamivir group（P ＞ 0.05）. The results of HE staining showed that Len-AlaNCs(100 mg·kg^-1) greatly relieved the bloodstasis and inflammatory response in lung tissue, and the therapeutic effect approached that of oseltamivir group and control group. Conclusion Len-Ala-NCs effectively improved oral bioavailability of alantolactone, and enhanced the therapeutic effect of influenza virus infection in mice.

R944.9;R978.7

河南省科技攻关项目(232102310384); 骨干教师培养计划(2023zygg08)