Effect of curcumin on multidrug resistance in resistant human gastric carcinoma cell line SGC7901/VCR

AIM: To investigate the reversal effects of curcumin on multidrug resistance (MDR) in a resistant human gastric carcinoma cell line. METHODS: The cytotoxic effect of vincristine (VCR) was evaluated by MTT assay. The cell apoptosis induced by VCR was determined by propidium iodide (PI)-stained flow cytometry (FCM) and a morphological assay using acridine orange (AO)/ethidium bromide (EB) dual staining. P-glycoprotein (P-gp) function was demonstrated by the accumulation and efflux of rhodamine123 (Rh123) using FCM. The expression of P-gp and the activation of caspase-3 were measured by FCM using fluorescein isothiocyanate (FITC)-conjugated anti-P-gp and anti-cleaved caspase-3 antibodies, respectively. RESULTS: Curcumin, at concentrations of 5 micromol/L, 10 micromol/L, or 20 micromol/L, had no cytotoxic effect on a parent human gastric carcinoma cell line (SGC7901) or its VCR-resistant variant cell line (SGC7901/VCR). The VCR-IC50 value of the SGC7901/VCR cells was 45 times more than that of the SGC7901cells and the SGC7901/VCR cells showed apoptotic resistance to VCR. SGC7901/VCR cells treated with 5 micromol/L, 10 micromol/L, or 20 micromol/L curcumin decreased the IC50 value of VCR and promoted VCR-mediated apoptosis in a dose-dependent manner. Curcumin (10 micromol/L) increased Rh123 accumulation and inhibited the efflux of Rh123 in SGC7901/VCR cells, but did not change the accumulation and efflux of Rh123 in SGC7901 cells. P-gp was overexpressed in SGC7901/VCR cells, whereas it was downregulated after a 24-h treatment with curcumin (10 micromol/L). Resistant cells treated with 1 mumol/L VCR alone showed 77% lower levels of caspase-3 activation relative to SGC7901 cells, but the activation of caspase-3 in the resistant cell line increased by 44% when cells were treated with VCR in combination with curcumin. CONCLUSION: Curcumin can reverse the MDR of the human gastric carcinoma SGC7901/VCR cell line. This might be associated with decreased P-gp function and expression, and the promotion of caspase-3 activation in MDR cells.     

PNIPAM nanoparticles for targeted and enhanced nose-to-brain delivery of curcuminoids: UPLC/ESI-Q-ToF-MS/MS-based pharmacokinetics and pharmacodynamic evaluation in cerebral ischemia model

Stroke is a one of the leading causes of disease and deaths worldwide, which causes irreversible deterioration of the central nervous system. Curcuminoids are reported to have a potential role in the amelioration of cerebral ischemia but they exhibit low serum and tissue levels due to low solubility and poor absorption. Curcumin (CUR), demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC)-loaded PNIPAM nanoparticles (NPs) were prepared by free radical polymerization and characterized for particles size, entrapment efficiency, zeta potential, in vitro release and ex vivo permeation study. Optimized CUR, DMC and BDMC-loaded NPs had the mean size of 92.46?±?2.8, 91.23?±?4.2 and 94.28?±?1.91?nm; zeta potential of ?16.2?±?1.42, ?15.6?±?1.33 and ?16.6?±?1.21 mV; loading capacity of 39.31?±?3.7, 38.91?±?3.6 and 40.61?±?3.6% and entrapment efficiency of 84.63?±?4.2, 84.71?±?3.99 and 85.73?±?4.31%, respectively. Ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectroscopy based bioanalytical method was developed and validated for pharmacokinetics, biodistribution, brain-targeting efficiency and brain drug-targeting potential studies post-intranasal (i.n.) administration which showed enhanced bioavailability of curcuminoids in brain as compared to intravenous administration. Improved neurobehavioural activity (locomotor and grip strength) and reduced cytokines levels (TNF-α and IL-1β) was observed in middle cerebral artery occlusion induced cerebral ischemic rats after i.n. administration of curcuminoids NPs. Finally, the toxicity study was performed which revealed safe nature of developed NPs.     

PCL-PEG-PCL载姜黄素纳米粒子的制备以及体外药物释放的考察

目的 制备一种生物可降解、生物相容性良好的姜黄素纳米粒子,并对其体外药物释放行为进行考察。方法 采用开环聚合法制备生物可降解的PCL-PEG-PCL三嵌段聚合物,然后采用乳液挥发法制备负载姜黄素的PCL-PEG-PCL纳米粒子,通过透射电镜观察所制备纳米粒子的形貌特征,动态光散射(DLS)测定粒径,采用HPLC测定纳米粒子的包封率和载药量,同时考察其体外药物释放行为。结果 姜黄素纳米粒子具有球形结构,粒径在200 nm左右,载药量为(14.23±0.35)%,3 d体外累积释药量65%。结论 所制备的姜黄素纳米粒子具有较高的载药量和包封率,同时体外药物释放实验证实姜黄素纳米粒子具有良好的缓释功能。     

Curcumin alleviates glucocorticoid‐induced osteoporosis by protecting osteoblasts from apoptosis in vivo and in vitro

Curcumin, an active component of the rhizomes of Curcumin longa L., possesses broad anti‐inflammation and anti‐cancer properties. Curcumin was previously reported to be capable of protecting ovariectomized rats against osteoporosis. However, the effect of curcumin on glucocorticoid‐induced osteoporosis (GIO) is not yet clear. The present study investigated the effects of curcumin on dexamethasone (Dex)‐induced osteoporosis in vivo and Dex‐induced osteoblast apoptosis in vivo and in vitro. The GIO rat model was induced by subcutaneous injection of Dex for 60 days and verified to be successful as evidenced by the significantly decreased bone mineral density (BMD) determined using dual X‐ray absorptiometry. Subsequently, curcumin administration (100 mg/kg) for 60 days obviously increased BMD and bone‐alkaline phosphatase, decreased carboxy‐terminal collagen cross links, enhanced bone mechanical strength, and improved trabecular microstructure, thereby alleviating Dex‐induced osteoporosis. Mechanically, curcumin remarkably reversed Dex‐induced femoral osteoblast apoptosis in vivo. In cultured primary osteoblasts, pretreatment with curcumin concentration‐dependently decreased the number of Dex‐induced apoptotic osteoblasts by down‐regulating the ratio of Bax/Bcl‐2 as well as the levels of cleaved caspase‐3 and cleaved poly ADP‐ribose polymerase (PARP). Moreover, curcumin pretreatment activated extracellular signal regulated kinase (ERK) signalling in Dex‐induced osteoblasts by up‐regulating the expression level of p‐ERK1/2. Taken together, our study demonstrated that curcumin could ameliorate GIO by protecting osteoblasts from apoptosis, which was possibly related to the activation of the ERK pathway. The results suggest that curcumin may be a promising drug for prevention and treatment of GIO.     

姜黄素的水溶性药物递送系统的研究进展

天然活性产物姜黄素具备良好的药理学、药效学活性及用药安全性,近年来其抗肿瘤活性成为研究热点,但是姜黄素水溶性差、易降解、生物利用度低的特点限制了其应用。因此姜黄素水溶性剂型的研制与开发成为解决其临床应用的一种有效途径,本文对近年来姜黄素新剂型的研究进展进行概述。     

姜黄素对人胚肺成纤维细胞转化生长因子β受体的影响

目的探讨姜黄素对经转化生长因子β(TGF-β)诱导后人胚肺成纤维细胞TGF-βⅠ、Ⅱ型受体(TGF-βRⅠ、RⅡ)在人胚肺成纤维细胞中表达的影响,及其与特发性肺纤维化的关系。方法细胞分为正常组、姜黄素组、模型组、治疗组,采用RT-PCR、Western blotting法检测TGF-βRⅠ、RⅡ在人胚肺成纤维细胞的变化。结果模型组TGF-βRⅠ与RⅡ表达增强,治疗组与正常组、模型组相比,TGF-βRⅠ与RⅡ表达明显减弱。结论姜黄素可抑制人胚肺成纤维细胞的胶原沉积,在延缓肺纤维化形成中起一定作用,其作用机制可能是通过抑制TGF-βRⅠ与RⅡ的表达而实现的。     

姜黄素对大鼠血瘀性脑缺血模型血液流变学及脑匀浆LD、LDH和TchE水平的影响

目的:探讨姜黄素对血瘀性脑缺血模型的作用特点。方法:采用肌肉注射地塞米松造血瘀模型,给血瘀模型大鼠连续灌服姜黄素混悬液10天,于第11天灌相应药物后1h,大鼠两侧颈总动脉作结扎30min,造脑缺血模型;取血肝素抗凝,测血液流变学;取大鼠脑组织用生理盐水制脑匀浆,测脑匀浆LD、LDH和TchE水平。结果:肌肉注射地塞米松造血瘀模型成功,结扎双侧颈总动脉造脑缺血模型成功;与模型组比,姜黄素可显著降低全血高低切粘度、红细胞聚集指数、全血高低切还原粘度及红细胞刚性,可显著降低脑匀浆乳酸含量,可显著提高脑匀浆乳酸脱氢酶水平及胆碱酯酶水平。结论:姜黄素可显著改善大鼠血瘀性脑缺血模型血液流变学及脑匀浆生化指标。     

姜黄素对过氧化氢诱导氧化损伤的小鼠脑神经瘤细胞的保护作用

<正>姜黄素(curcumin)是从姜科植物Curcumalonga根茎中分离得到的一种脂溶性多酚类化合物,具有抗肿瘤、抗炎症、抗氧化、抗纤维化、保护心血管系统和消化系统等功能[1-2]。近来研究     

Dietary polyphenols and obesity

The prevalence of overweight and obesity and their associated metabolic disorders are considered a major threat to the public's health. While several diet and exercise programs are available for weight loss and prevention of weight regain, progress is often slow and disappointing. Recently, natural bioactive phytochemicals present in foods have been discovered for their potential health benefit effects on the prevention of chronic disorders such as cancer, cardiovascular disease, inflammatory and metabolic diseases including obesity. Polyphenols are a class of naturally-occurring phytochemicals, of which some such as catechins, anthocynines, resveratrol and curcumin have been shown to modulate physiological and molecular pathways that are involved in energy metabolism, adiposity, and obesity. The potential in vivo, beneficial effects of these polyphenols on adiposity and obesity as complementary agents in the up-regulation of energy expenditure have emerged by investigating these compounds in cell cultures, animal models of obesity and in some human clinical and epidemiological studies. In this brief review, the efficacy of the above-named polyphenols and their potential efficacy to modulate obesity and some associated disorders are discussed.     

姜黄素-PLGA纳米粒提高口服给药生物利用度的研究

目的 研究乳酸/羟基乙酸共聚物（PLGA）纳米粒子提高姜黄素口服生物利用度。方法 采用乳液挥发法制备姜黄素-PLGA纳米粒;通过透射电镜（transmission electron microscope,TEM）观察纳米粒形态;采用动态光散射法（dynamic light scattering,DLS）测定纳米粒大小、表面电位（Zeta电位）;考察药物的体外稳定性以及药物释放行为;以大鼠口服灌胃给药方式考察姜黄素和姜黄素-PLGA纳米粒的体内药物生物利用度。结果 姜黄素-PLGA纳米粒粒度分布均匀,平均粒径大小约200 nm;姜黄素-PLGA纳米粒具有较高的载药量和包封率以及稳定性,体外药物释放实验结果显示具有一定的缓释效果;口服灌胃100 mg·kg^-1姜黄素和姜黄素-PLGA纳米粒,给药30 min之后,姜黄素-PLGA纳米粒给药组的血药浓度水平显著高于姜黄素组（P〈0.05）,药物生物利用度提高到原来的5.2倍。结论 姜黄素-PLGA纳米粒可以有效的提高姜黄素稳定性和口服给药生物利用度。