目的 制备负载芹菜素玉米肽纳米粒（Api-CP-NPs），考察其口服药动学特征及对自发性高血压（SH）大鼠的治疗效果。方法 采用自组装法制备Api-CP-NPs，通过单因素实验结合Box-Behnken设计-响应面法优化处方工艺。运用透射电子显微镜（TEM）观察微观形貌、X-射线粉末衍射法（XRPD）分析晶体结构，对纳米粒进行表征。比较芹菜素原料药与ApiCP-NPs在模拟胃、肠液中的降解动力学差异，采用透析袋法研究Api-CP-NPs的体外释药行为。对SH大鼠分别ig给予芹菜素原料药与Api-CP-NPs，计算主要药动学参数。将36只雄性SH大鼠随机分为模型组、卡托普利（阳性药，10 mg·kg_-1）组、玉米肽（1.66 g·kg_-1）组、芹菜素（100 mg·kg_-1）组及Api-CP-NPs低、高剂量（50、100 mg·kg_-1）组，另取6只WKY大鼠作为对照组。给药后每周监测血压，采用ELISA法测定血清中肾素（REN）、血管紧张素Ⅱ（Ang Ⅱ）及醛固酮（ALD）含量，苏木素-伊红（HE）染色法测量颈动脉厚度及观察血管病理形态。结果 优化得到的Api-CP-NPs最佳处方为：玉米肽质量浓度8.30 mg·mL^-1，制备温度47.50℃，制备时间3.00 h。该条件下制备的Api-CP-NPs，包封率、载药量、粒径及Zeta电位分别为（87.91± 1.04）%、（5.33± 0.12）%、（72.74± 3.45） nm及（-18.98± 0.63） mV。TEM观察显示Api-CP-NPs呈不规则球形，XRPD结果表明芹菜素在纳米粒中以无定形态存在。Api-CP-NPs可显著降低芹菜素在模拟胃肠液中的降解速率，同时大幅提高其在模拟肠液中的累积释放率。口服药动学结果显示，与芹菜素原料药相比，Api-CP-NPs的达峰时间（t_max）延迟至（2.11± 0.43） h，达峰浓度（C_max）升高至（2.58±0.87） μg·mL^-1，半衰期（t_1/2）延长至（5.50±1.76） h，血药浓度-时间曲线下面积（AUC_0～t）提高4.14倍，提示Api-CP-NPs可显著促进芹菜素的体内吸收。药效学结果显示，与模型组相比，芹菜素组在给药第3、4周血压显著下降（P＜0.05），与芹菜素组相比，Api-CP-NPs高剂量组给药第2周血压显著下降（P＜0.05），第3、4周血压极显著下降（P＜0.01）；同时，该组血清Ang Ⅱ、ALD含量极显著降低（P＜0.01），动脉中膜厚度极显著变薄（P＜0.01），中膜结构紊乱情况明显改善。结论 Api-CP-NPs可显著提高芹菜素的体外稳定性，促进其体内吸收，进而增强芹菜素对SH大鼠的治疗效果。

Objective To prepare apigenin-corn peptide nanoparticles (Api-CP-NPs) and investigate their oral pharmacokinetic characteristics and therapeutic effects on spontaneously hypertensive (SH) rats. Methods Api-CP-NPs were prepared by selfassembly method. The prescription and process were optimized by single factor experiments combined with Box-Behnken designresponse surface methodology. The nanoparticles were characterized by transmission electron microscopy (TEM) for microscopic morphology and X-ray powder diffraction (XRPD) for crystal structure. The degradation kinetics of apigenin raw material and ApiCP-NPs in simulated gastrointestinal fluid were compared, and the in vitro drug release behavior of Api-CP-NPs was studied by dialysis bag method. SH rats were ig administered with apigenin raw material and Api-CP-NPs, and the main pharmacokinetic parameters were calculated. Thirty-six male SH rats were randomly divided into model group, captopril positive drug group (10 mg·kg^-1), corn peptide group (1.66 g·kg^-1), apigenin group (100 mg·kg^-1), and low and high dose Api-CP-NPs groups (50, 100 mg·kg^-1), and another six WKY rats were used as the control group. Blood pressure was monitored weekly after administration. The contents of renin (REN), angiotensin II (Ang II) and aldosterone (ALD) in serum were determined by ELISA, and the pathological morphology of arterial vessels was observed by HE staining. Results The optimal prescription of Api-CP-NPs was obtained as follows: corn peptide mass concentration 8.30 mg·mL^-1, preparation temperature 47.50 ℃, and preparation time 3.00 h. Under these conditions, the encapsulation efficiency, drug loading, particle size and ζ potential of Api-CP-NPs were (87.91 ± 1.04)%, (5.33 ± 0.12)%, (72.74 ± 3.45) nm and (-18.98 ± 0.63) mV, respectively. TEM observation showed that Api-CP-NPs were irregular spherical, and XRPD results indicated that apigenin existed in an amorphous state in the nanoparticles. Api-CP-NPs could significantly reduce the degradation rate of apigenin in simulated gastrointestinal fluid and greatly increase its cumulative release in simulated intestinal fluid. The oral pharmacokinetic results showed that compared with apigenin raw material, the peak time (t_max) of Api-CP-NPs was delayed to (2.11 ± 0.43) h, the peak concentration (C_max) increased to (2.58 ± 0.87) μg·mL^-1, the half-life (t_1/2) was prolonged to (5.50 ± 1.76) h, and the area under the blood concentration-time curve (AUC_0～t) increased by 4.14 times, suggesting that Api-CP-NPs could significantly promote the in vivo absorption of apigenin. Pharmacodynamic results showed that compared with the model group, the apigenin group had a significant decrease in blood pressure at the 3rd and 4th weeks of administration (P < 0.05). Compared with the apigenin group, the high-dose Api-CP-NPs group had a significant decrease in blood pressure at the 2nd week of administration (P < 0.05), and a highly significant decrease at the 3rd and 4th weeks (P < 0.01). Meanwhile, the content of Ang Ⅱ and ALD in the serum of this group was highly significantly reduced (P < 0.01), and the thickness of the arterial media was highly significantly thinned (P < 0.01), with a significant improvement in the disordered structure of the media. Conclusion Api-CP-NPs can significantly improve the in vitro stability of apigenin, promote its in vivo absorption, and thereby enhance the therapeutic effect of apigenin on SH rats.

R285.5

河南省科技攻关项目（232102310384）