翻白草总黄酮微乳的制备及其对糖尿病小鼠的治疗作用

摘要

AIM To prepare the microemulsions loaded with total flavonoids from Potentilla discolor Bunge and to evaluate the therapeutic effect on diabetic mice.METHODS Total flavonoids,the extract from P.discolor by 70％ ethanol,were made into microemulsions after purification with.macroporous resin.With types and amount of oil phase,emulsifier and co-emulsifier,and addition amount of total flavonoids as influencing factors,together with drug loading,encapsulation efficiency,particle size and Zeta potential as evaluation indices,the formulation was optimized by drawing pseudo-ternary phase diagram.By establishing diabetic mouse models induced by streptozotocin (STZ) and high fat diet,the obtained microemulsions' effects on fasting blood glucose,oral glucose tolerance (OGT),insulin,glycosylated serum protein (GSP),triglyceride (TG),total cholesterol (TC),low density lipoprotein (LDL),high density lipoprotein (HDL),superoxide dismutase (SOD) and malondialdehyde (MDA) in mice were investigated.RESULTS The optimal formulation was determined to be 400 mg for isopropyl myristate (oil phase) amount,400 mg for Cremophor RH 40 (emulsifier) amount,200 mg for polyethylene glycol 400 (coemulsifier) amount,and 80 mg for addition amount of total flavonoids.The spherical-like and uniformly-sized microemulsions shared average drug loading of (7.28 ± 0.12)％,encapsulation efficiency of (91.79 ± 1.02)％,particle size of (36.79 ±0.17) nm and Zeta potential of (-15.77 ±2.89) mV.They could significantly reduce fasting blood glucose level,promote insulin secretion,regulate blood lipid,increase SOD activity,and decrease MDA level in diabetic mice.CONCLUSION Once prepared into microemulsions,the total flavonoids from P.discolor demonstrate an obviously enhanced activity in reducing blood glucose.%目的 制备翻白草Potentilla discolor Bunge总黄酮微乳,并评价其对糖尿病小鼠的治疗作用.方法 70％乙醇和大孔树脂提取纯化翻白草总黄酮后,制备微乳.以油相、乳化剂、助乳化剂种类和用量、总黄酮加入量为影响因素,载药量、包封率、粒径、Zeta电位为评价指标,通过绘制伪三元相图优化处方.建立链脲佐菌素(STZ)结合高脂饲料诱导糖尿病小鼠模型,考察所得微乳对小鼠空腹血糖、口服糖耐量(OGT)、胰岛素、糖化血清蛋白(GSP)、甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)、超氧化物歧化酶(SOD)、丙二醛(MDA)的影响.结果 最佳处方为肉豆蔻酸异丙酯(油相)用量400 mg,Cremophor RH 40(乳化剂)用量400 mg,聚乙二醇400(助乳化剂)用量200 mg,总黄酮加入量80 mg.所得微乳呈类球形,大小均一,平均载药量(7.28±0.12)％,包封率(91.79±1.02)％,粒径(36.79±0.17) nm,Zeta电位(-15.77±2.89)mV.它们能显著降低糖尿病小鼠空腹血糖水平,促进胰岛素分泌,调节血脂,提高SOD活性,降低MDA水平.结论 翻白草总黄酮制成微乳后,可显著增强其降血糖的作用.