聚乙二醇1000维生素E琥珀酸酯-皂皮皂素微乳液的制备、表征及活性

选用毒性小、刺激性低且有P-糖蛋白抑制剂作用的聚乙二醇1000维生素E琥珀酸酯（D-α-tocopheryl polyethylene glycol 1000 succinate，TPGS）和乳化效果强的天然植物化合物皂皮皂素（quillaja saponin，QS），与聚氧乙烯氢化蓖麻油（RH40）复配为乳化剂，再以油酸乙酯为油相，异丙醇为助乳化剂，配制TPGS-QS微乳液。利用普通光学显微镜、透射电子显微镜和激光粒度测定仪观察微乳液液滴形貌、粒径分布和Zeta电位。结果：TPGS-QS微乳液具体配制方法为m（油酸乙酯）∶m（质量分数0.02%?TPGS溶液）∶m（质量分数1.5%?QS溶液）∶m（RH40）∶m（异丙醇）＝30∶6.6∶6.6∶39.4∶17.5，所用溶液均以纯水配制。该微乳液外观淡黄、澄清、透明，流动性强，液滴呈均一规则的圆球形，为O/W型乳液，微乳液平均粒径为（48.89±0.08）nm，Zeta电位为（－4.513±0.564）mV。为验证TPGS-QS微乳液是否具有生物活性，测定其α-葡萄糖苷酶抑制活性、1,1-二苯基-2-三硝基苯肼自由基清除能力、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除能力、铁离子还原能力，及其对HepG2和Caco-2细胞的毒性作用，发现该微乳液对α-葡萄糖苷酶活性的半抑制质量浓度为67.15?mg/mL，具有一定的抗氧化活性，并且几乎不会影响细胞的正常生长，甚至在一定质量浓度范围对细胞有增殖效果。

Effects of Bamboo Leaf Extract on the Quality and Nitrite Content of Low-Nitrite Western-Style Smoked Ham

D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), an inhibitor of P-glycoprotein (P-gp) with low toxicity and irritation, and the natural phytochemical quillaja saponin (QS), with a strong emulsifying effect, were selected for mixing with ethoxylated hydrogenated castor oil (RH40) as emulsifiers to prepare TPGS-QS microemulsion with ethyl oleate as an oil phase and isopropanol as a co-emulsifier. The morphology, particle size and zeta potential of emulsion droplets were observed by optical microscopy (OM), transmission electron microscopy (TEM) and laser particle size analyzer. The optimal microemulsion formulation consisted of a mixture of ethyl oleate, 0.02% TPGS, 1.5% QS, RH40 and isopropanol at a ratio of 30:6.6:6.6:39.4:17.5 (m/m). All solutions were prepared with purified water. The microemulsion was yellowish, clear and transparent in appearance with strong fluidity, and it was identified as an O/W-type emulsion with uniform spherical droplets. In addition, its average particle size was (48.89 ± 0.08) nm, and its zeta potential was (–4.513 ± 0.564) mV. The α-glycosidase inhibitory activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) cation radical scavenging capacity and iron reducing power of TPGS-QS microemulsion was tested, and its in vitro cytotoxicity on HepG2 and Caco-2 cells was evaluated through MTT assay. The half-maximal inhibitory concentration against α-glycosidase was 67.15 mg/mL, and the emulsion had antioxidant activity. It hardly affected the normal growth of cells, but even had a promoting effect on cell proliferation within a certain concentration range.