Purification of naringin and neohesperidin from Huyou (Citrus changshanensis) fruit and their effects on glucose consumption in human HepG2 cells

Huyou (Citrus changshanensis) is rich in naringin and neohesperidin, which are natural flavanone glycosides with a range of biological activities. Among the different fruit parts, i.e. flavedo, albedo, segment membrane (SM), and juice sacs (JS), albedo showed the highest contents of both compounds, with 27.00 and 19.09mg/g DW for naringin and neohesperidin, respectively. Efficient simultaneous purification of naringin and neohesperidin from Huyou albedo was established by the combination of macroporous D101 resin chromatography and high-speed counter-current chromatography (HSCCC). Purified naringin and neohesperidin were identified by both HPLC and LC-MS, and their effects on glucose consumption were investigated in HepG2 cells. Cells treated with naringin and neohesperidin showed increased consumption of glucose, and this was associated with increased phosphorylation of AMP-activated protein kinase (AMPK). Therefore, naringin and neohesperidin from Huyou may act as potential hypoglycaemic agents through regulation of glucose metabolism.     

柚皮苷对人卵巢癌SKOV3细胞P38MAPK及ERK1/2蛋白表达的影响

目的: 探讨中药柚皮苷对人卵巢癌SKOV3细胞P38MAPK及ERK1/2蛋白表达水平的影响。方法: 体外培养人卵巢癌SKOV3细胞,分为空白对照组、柚皮苷10、20、40 μmol/L 组、塞来昔布 80 μmol/L 组。Western Blot测定培养 48 h 后各组细胞中P38MAPK及ERK1/2蛋白表达水平。结果: Western Blot结果显示,与空白对照组相比,低浓度柚皮苷组(10、20 μmol/L)对SKOV3细胞P38MAPK及ERK1/2蛋白的表达无明显影响,而 40 μmol/L 柚皮苷及塞来昔布组可明显下调P38MAPK及ERK1/2蛋白表达,具有统计学差异(P<0.05)。结论: 柚皮苷能抑制人卵巢癌SKOV3细胞P38MAPK及ERK1/2蛋白的作用,从而可能阻断卵巢癌的发生、发展。     

柑桔酒苦味的产生及脱苦

柑桔酒苦味主要来源于两个方面：一方面在柑桔汁加工过程中产生;另一方面来源于柑桔酒酿选及陈酿过程。本文根据苦味的产生,对如何分阶段将柑桔酒脱苦作了综述。     

Design and synthesis of mixed micellar system for enhanced anticancer efficacy of Paclitaxel through its co-delivery with Naringin

Emergence of multidrug resistance (MDR) has limited the success of chemotherapeutic agents. Reversal of drugs efflux systems through combination therapy has got wider attention for increasing anticancer drugs efficacy. This study aims at co-encapsulation of Paclitaxel with Naringin in mixed polymeric micelles for enhanced anticancer activity of the drug. Drug-loaded micelles were prepared using two different amphiphilic block co-polymers and were characterized for morphology, size, zeta potential, drug encapsulation, in vitro release and stability using atomic force microscope (AFM), zetasizer, UV spectrophotometer, and FT-IR. MTT assay and fluorescence microscopy were used for in vitro cytotoxicity and cellular uptake studies. Nano-size micelles with spherical morphology and negative charge encapsulated 76.52?±?0.94% and 32.87 0.61% Paclitaxel and Naringin, respectively. The micelles were thermally stable and retained 87.05?±?0.69% and 92.88?±?2.17% Paclitaxel and Naringin upon one-month storage. Maximum drug release was achieved at fourth hour of the study for both the loaded drugs. Paclitaxel co-encapsulation with Naringin synergistically improved its intracellular uptake and 65% in vitro cytotoxicity against breast cancer cells was achieved at its lower dose of 15?µg/mL. Results suggest that co-encapsulation of Paclitaxel with Naringin in mixed micelles is an effective strategy for achieving its higher anticancer activity.     

Contribution of response surface methodology to the modeling of naringin hydrolysis by naringinase Ca-alginate beads under high pressure

Naringin is the dominant flavonoid bitter principle in grapefruit juice. The aim of this work was the modeling of the enzymatic hydrolysis of naringin, with naringinase immobilised in Ca-alginate beads, under high pressure, in order to optimize this technique for removal of the bitter taste from juices, using response surface methodology (RSM). A central composite rotatable design (CCRD) was employed involving two variables (pressure and temperature) at five levels (−√2, −1, 0, +1, +√2). The second-order polynomial equations with R² values above 0.9 showed good agreement between experimental and predicted, respectively, naringinase activity, naringin conversion and naringenin formation. The higher naringin conversion of 81% was obtained using 205 MPa and 60 °C, during a process time of 30 min.It was found that pressure and temperature, as well as their interactions, had significant effects (p < 0.001) on naringin hydrolysis in model solutions (acetate buffer pH 4.0). Validation experiments carried out under selected conditions showed good correspondence between experimental and predicted naringinase activity, naringin conversion and naringenin formation, in model solutions and in grapefruit juice.These are promising results to optimize this technique for the removal of the bitter taste and, after future microbial studies to be addressed, as a sterilisation/pasteurization process of citrus juices.     

柚皮苷的药物代谢动力学研究概况与进展

柚皮苷是一种二氢黄酮类化合物,具有促进胃肠蠕动功能,主要存在于枳壳、枳实、骨碎补、化橘红等中药中。柚皮苷的口服吸收差,体内分布广泛,主要经开环、脱氢、裂解等反应产生对羟基苯丙酸、对羟基桂皮酸等代谢产物而排出体外。同时柚皮苷还能够通过抑制部分转运体、代谢酶的活性与其他药物发生相互作用,从而影响其他药物的代谢过程。本文通过综述柚皮苷的药物代谢动力学特征及柚皮苷对其他药物的代谢动力学的影响,发现柚皮苷代谢过程的相互作用机制及基因多态性对其药代动力学特征的影响尚需深入研究。     

两步生物法转化柚皮苷制备L-鼠李糖

考察了利用柚苷酶和酵母静息细胞作为催化剂,两步生物法转化柚皮苷制备L-鼠李糖的工艺过程。柚苷酶水解柚皮苷的最佳工艺条件是ρ(柚皮苷)=14 g/L的水溶液为底物,加酶量10 mL/L(即每升底物中加入酶的体积,下同),pH=5.5,酶解时间22 h。酵母代谢葡萄糖的最佳工艺条件是酵母用量2.5 g/L(即每升水解液中加入酵母的质量,下同),温度32℃,pH=6.0,发酵时间120 min。在30 L发酵罐中进行了小试,最终获得了质量分数大于98.5%的鼠李糖结晶85.6 g,为理论得率的86.5%。     

柑橘类柚皮苷提取工艺研究

采用正交试验与单因素实验相结合方法,对影响柚皮苷提取率的主要因素进行研究.结果表明,从柚皮中提取柚皮苷的较佳条件为:用饱和Ca(OH)2溶液作溶剂,料液比1:10,温度60℃,提取时问3h.     

RP-HPLC法测定不同产地枳实中的柚皮苷、橙皮苷及新橙皮苷

目的:建立同时测定枳实中柚皮苷、橙皮苷和新橙皮苷含量的方法.方法:采用反相高效液相色谱法分离检测柚皮苷、橙皮苷和新橙皮苷,色谱柱为Hypersil ODS2(250 mm ×4.6 mm,5μm大连依利特公司),流动相为乙腈-水(20:80),流速为1.0 mL/min,检测波长283 nm,柱温为30 ℃.结果:柚皮苷、新橙皮苷在1.00～7.50μg,橙皮苷在0.40～3.00 μg与峰面积呈良好的线性关系.柚皮苷、橙皮苷、新橙皮苷的平均回收率分别为100.56%(RSD=0.55%)、100.20%(RSD=1.00%)、101.14%(RSD=1.74%).结论:该方法简便、准确、可靠、重复性好,可用于枳实药材的质量控制.     

Immobilization and characterization of naringinase for the hydrolysis of naringin

The degree of hydrolysis of naringin was investigated at various temperatures (40, 50, 60 °C), enzyme concentrations (0.01–0.30 mg ml⁻¹), and pH values (2.5–5.5) for naringinase enzyme. Naringinase was immobilized on celite by simple adsorption. Naringin content was determined by HPLC method. The degree of hydrolysis of naringin showed a linear increase up to an enzyme concentration of 0.2 mg ml⁻¹ that corresponds to 82% hydrolysis. The optimum values of pH for the hydrolysis of naringin were 4.0 for free and 3.5 for immobilized enzymes. Maximum enzyme activities were found to be 70 and 60 °C for free and immobilized enzymes, respectively. The values of K _m,app and V _max,app calculated were 1.22 mM and 0.45 μmol min⁻¹ mg enzyme⁻¹ for free and 2.16 mM and 0.3 μmol min⁻¹ mg enzyme⁻¹ for immobilized enzyme, respectively. The mathematical modelling was applied to the experimental data for hydrolysis of naringin as a function of time at 30, 40 and 50 °C. The increase in temperature from 30 to 50 °C increased the rate constant 3.09 times for free enzyme. However, the rate constants found for immobilized enzyme applications did not increase in a similar trend as a function of temperature. The retained activity of celite-adsorbed naringinase was found to be 83% at their optimum conditions. The retained activity of immobilized enzyme was followed up to the fifth run and was found to be almost unchanged after the third use at optimum reaction conditions (pH 3.5, 60 °C).