κ-卡拉胶/黄原胶骨架片的体外释药特性

目的:研究κ-卡拉胶/黄原胶骨架片的体外药物释放,探讨其释药特性。方法:采用κ-卡拉胶和黄原胶复配作为骨架材料,以阿司匹林为模型药物,湿法制粒压片制备骨架片,测定骨架片在不同pH值、离子强度的释放介质和搅拌转速条件下的体外释放度和骨架片溶蚀程度,分别采用零级方程和Peppas方程对骨架片的溶蚀度和释放数据进行拟合。结果:骨架片在pH6.8磷酸盐缓冲液中药物释放最快,纯化水中次之,0.1 mol/L盐酸液中最慢;药物释放随介质离子强度增加而减慢;药物释放随搅拌转速增加而加快;骨架片的药物释放机制为扩散和溶蚀释放协同作用。结论:κ-卡拉胶与黄原胶复配作为骨架材料可延缓骨架片中药物的释放。     

Antinociceptive effects of the N-acylethanolamine acid amidase inhibitor ARN077 in rodent pain models

Fatty acid ethanolamides (FAEs), which include palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), are endogenous agonists of peroxisome proliferator-activated receptor-α (PPAR-α) and important regulators of the inflammatory response. They are degraded in macrophages by the lysosomal cysteine amidase, N-acylethanolamine acid amidase (NAAA). Previous studies have shown that pharmacological inhibition of NAAA activity suppresses macrophage activation in vitro and causes marked anti-inflammatory effects in vivo, which is suggestive of a role for NAAA in the control of inflammation. It is still unknown, however, whether NAAA-mediated FAE deactivation might regulate pain signaling. The present study examined the effects of ARN077, a potent and selective NAAA inhibitor recently disclosed by our group, in rodent models of hyperalgesia and allodynia caused by inflammation or nerve damage. Topical administration of ARN077 attenuated, in a dose-dependent manner, heat hyperalgesia and mechanical allodynia elicited in mice by carrageenan injection or sciatic nerve ligation. The antinociceptive effects of ARN077 were prevented by the selective PPAR-α antagonist GW6471 and did not occur in PPAR-α–deficient mice. Furthermore, topical ARN077 reversed the allodynia caused by ultraviolet B radiation in rats, and this effect was blocked by pretreatment with GW6471. Sciatic nerve ligation or application of the proinflammatory phorbol ester 12-O-tetradecanoylphorbol 13-acetate decreased FAE levels in sciatic nerve and skin tissue, respectively. ARN077 reversed these biochemical effects. The results identify ARN077 as a potent inhibitor of intracellular NAAA activity, which is active in vivo by topical administration. The findings further suggest that NAAA regulates peripheral pain initiation by interrupting endogenous FAE signaling at PPAR-α.     

Compression behaviour of κ-carrageenan pellets

The compression behavior of high- and low drug strength pellets containing κ-carrageenan as pelletisation aid was investigated. Model drugs and fillers with different compression mechanisms were used and the effects of compression force and turret speed were examined. Regardless of the compression behavior of their starting components, all pellet formulations exhibited minimal to absent fragmentation and underwent compression by deformation, confirmed by increased equivalent diameter and aspect ratio and decreased roundness factor of the pellets retrieved after de-aggregation of tablets prepared from lubricated pellets. The retrieved pellets showed also higher fracture resistance in three of the tested formulations and no statistically significant difference in the remaining one thus excluding significant crack formation. A densification mechanism was suggested by decreased total porosity and reduced median pore radius of the compressed pellets. No effect of the process parameters on the degree of pellet deformation was reported. The tensile strength of the tablets prepared from unlubricated pellets increased slightly with increased compression force. Compression of pellets with high density silicified microcrystalline cellulose (SMCC HD 90) as embedding powder protected them from severe deformation and resulted in tablets with sufficient tensile strength, minimal friability, negligible elastic recovery and short disintegration time. The percentage of the pellets and the compression force affected the tensile strength of the prepared tablets whereas no influence of the turret speed and the pre-compression force was observed.     

Selective inhibition of cell proliferation and DNA synthesis by the polysulphated carbohydrate ι-carrageenan

-Carrageenan is a polysulphated carbohydrate that antagonises some heparin-binding growth factors. We assessed the effect of -carrageenan on the proliferation of a panel of cell lines, some of which require heparin-binding growth factors for mitogenesis. The importance of growth factor antagonism for the antiproliferative activity was also determined. Cell proliferation was determined by cell counts and a tetrazolium dye (MTT) assay, and DNA synthesis was determined by thymidine incorporation. The proliferation of the basic fibroblast growth factor (bFGF)-dependent endothelial cell line FBHE was inhibited by daily administration of -carrageenan in a dose-dependent manner [concentration inhibiting cell growth by 50% (IC₅₀ value), approx. 0.5 g/ml]. However, excess bFGF did not reverse the inhibitory effect. DNA synthesis was completely inhibited by concentrations of -carrageenan that nonetheless allowed significant protein synthesis to occur. The proliferation of the androgen-dependent prostate-carcinoma cell line LNCaP was also inhibited by -carrageenan (IC₅₀ value, 5.5 g/ml) and the cells were arrested at the G1/S boundary. -Carrageenan inhibited DNA synthesis in MCF-7 cells stimulated by bFGF and transforming growth factor (TGF) but not in those stimulated by insulin-like growth factor 1 (IGF-1). Blocking IGF-1-mediated DNA synthesis with anti-IGF-1 receptor antibody IR3 enhanced the inhibitory activity of -carrageenan against MCF-7 cells grown in serum. A number of other transformed and non-transformed cell lines were either partially inhibited or not inhibited by -carrageenan. -Carrageenan had low anti-coagulant activity. -Carrageenan is a selective anti-proliferative agent and warrants further investigation for anti-angiogenic therapy (in view of its activity against endothelial cells) and for the treatment of androgen-dependent prostate cancer.     

ɩ-卡拉胶抗肠道病毒71型研究

目的 对海洋来源的化合物?-卡拉胶进行体外抗肠道病毒71型活性研究。方法 CPE抑制实验评价?-卡拉胶抗肠道病毒71型的活性,CPE实验探究?-卡拉胶的细胞毒性。通过空斑实验、Western blot实验、实时荧光定量PCR实验探究?-卡拉胶的抗病毒活性。利用Co-IP实验探究其作用靶点。结果 ?-卡拉胶具有高效低毒的抗肠道病毒71型活性,在Vero细胞中效果最好,IC50为6.29 μg·mL?1,CC50大于1 mg·mL?1,不同作用方式和不同作用时间实验表明,?-卡拉胶主要起作用于病毒吸附后阶段,且0~2 h给药可以显著抑制病毒VP1蛋白表达。此外,?-卡拉胶可以与病毒VP1蛋白结合,从而影响病毒感染细胞。结论 ?-卡拉胶具有良好的体外抗肠道病毒71型活性,为发现和改造新的海洋来源的糖类化合物提供了借鉴,为寻找新的抗肠道病毒71型药物提供了新思路。