岩藻黄素在振荡剪切应力致EPCs功能改变及衰老中的影响作用

目的 探讨岩藻黄素（Fucoxanthin, FUCO）对振荡剪切应力作用下内皮祖细胞（Endothelial progenitor cells,EPCs）生物学功能及细胞衰老的影响作用。方法 采用Flexcell STR-4000平行板流动系统模拟体内扰动流剪切应力（振荡剪切应力,Oscillatory shear stress,OSS,± 4 dynes/cm2,1 Hz）并加载于EPCs;利用结晶紫染色法观察OSS作用后EPCs的形态学改变;应用Boyden小室、自发性细胞贴壁及Matrigel基质胶分别检测细胞迁移、粘附和体外血管形成能力的变化;采用Western Blot检测促沉默信息调节因子1（Silent mating type information regulation 2 homolog-1,SIRT1）蛋白和β-半乳糖苷酶法检测细胞衰老程度的改变;通过Dihydroethidium（DHE）荧光探针法检测细胞内超氧化物阴离子。结果 与静态培养组相比,OSS导致EPCs形态学发生明显改变,表现为细胞长宽比降低,细胞之间间距增加;而FUCO对OSS导致的EPCs形态学改变无显著影响作用;与OSS处理组相比,FUCO可显著促进EPCs的迁移（10.00±1.73 vs 21.00±2.65个/视野）、粘附（8.00±1.00 vs 20.00±1.73个/视野）及体外血管形成能力（8538.67±1231.47 vs 11009.33±570.08像素/视野）。进一步研究发现,FUCO可降低OSS导致的β-半乳糖苷酶阳性细胞比例（21.18±1.38% vs 12.69±3.94%）以及促进SIRT1蛋白表达上调;同时,FUCO可减弱OSS诱导的EPCs胞内超氧阴离子的产生（P<0.05）。结论 FUCO可缓解OSS环境下引发的EPCs细胞功能降低、细胞衰老的发生,提示其可有效提升内源性EPCs的血管修复能力。     

岩藻黄质对高脂饮食诱导的肥胖小鼠胰岛素抵抗的影响

研究岩藻黄质对高脂饮食诱导的肥胖小鼠胰岛素抵抗的作用及其分子机制。将50只C57BL/6J雄性小鼠随机分为正常组(10只)、高脂组(40只),高脂组经高脂饲料喂养12周形成肥胖胰岛素抵抗模型,将其随机分为模型组、岩藻黄质0.2%剂量组、岩藻黄质0.4%剂量组和二甲双胍组,每组10只,连续喂养含有相应药物饲料6周后,测定各组小鼠体质量和附睾脂肪质量;检测血清中空腹血糖(FBG)、空腹胰岛素(FINS)、总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDLC)、高密度脂蛋白胆固醇(HDL-C)含量,并计算胰岛素抵抗指数(HOMA-IR);HE染色法观察各组小鼠肝脏病理变化;Western blot法检测肝脏组织中胰岛素受体底物1(IRS-1)/磷酸肌醇-3-激酶(PI3K)/苏氨酸蛋白激酶(Akt)和过氧化物酶体增殖剂激活受体-γ(PPARγ)/胆固醇调节元件结合蛋白-1(SREBP-1)/脂肪酸合成酶(FAS)通路相关蛋白的表达。结果显示,与模型组相比,各给药组小鼠的体质量、附睾脂肪质量以及FBG,FINS,TC,TG,LDL-C,HOMA-IR水平,肝组织中PPARγ,SREBP-1和FAS蛋白表达显著降低(P<0.05或P<0.01),同时HDL-C水平及肝组织中p-IRS-1,IRS-1,PI3K,p-Akt的蛋白表达显著升高(P<0.05或P<0.01),且肝组织病理形态明显改善。结果表明,岩藻黄质可明显减轻肥胖小鼠的肥胖及糖脂紊乱,并改善胰岛素抵抗,其作用可能与调控IRS-1/PI3K/Akt和PPARγ/SREBP-1/FAS通路有关。     

The effects of Xanthigen™ in the weight management of obese premenopausal women with non-alcoholic fatty liver disease and normal liver fat

Aim: To investigate the effects of Xanthigen (brown marine algae fucoxanthin + pomegranate seed oil (PSO)) on body weight, body fat, liver lipids, and blood biochemistry; and Xanthigen and its individual components on resting energy expenditure (REE) in obese, non-diabetic female volunteers with non-alcoholic fatty liver disease (NAFLD) and normal liver fat (NLF) content.
Methods: Sixteen-week, double-blind, randomized, placebo-controlled study. Food record data, body composition, REE (only 41 volunteers with NAFLD) and blood sample analysis were assessed weekly for 16 weeks in 151 non-diabetic, obese premenopausal women with liver fat content above 11% (NAFLD) n = 113, and below 6.5% (NLF) n = 38.
Results: Xanthigen-600/2.4 mg (300 mg PSO + 300 mg brown seaweed extract containing 2.4 mg fucoxanthin) resulted in statistically significant reduction of body weight (5.5 ± 1.4 kg NAFLD group and 4.9 ± 1.2 kg NLF group, p < 0.05), waist circumference (NAFLD group only), body (3.5 ± 1.9 kg NAFLD group, p < 0.001; 3.6 ± 0.7 kg NLF group, p < 0.05) and liver fat content, liver enzymes (NAFLD group only), serum triglycerides and C-reactive protein. Weight loss and reduction in body and liver fat content occurred earlier in patients with NLF than in patients with NAFLD. Fucoxanthin ( > 2.4 mg) and Xanthigen-400/1.6 mg (200 mg PSO + 200 mg brown seaweed extract containing 1.6 mg fucoxanthin) significantly increased REE in NAFLD subjects compared to placebo.
Conclusions: Xanthigen promoted weight loss, reduced body and liver fat content, and improved liver function tests in obese non-diabetic women. Xanthigen and Fucoxanthin also increased REE. This product may be considered a promising food supplement in the management of obesity.     

Effects of fucoxanthin on lipopolysaccharide-induced inflammation in vitro and in vivo

The aim of the present study was to investigate the efficacy of fucoxanthin on endotoxin-induced uveitis (EIU) in rats. The effects of fucoxanthin on endotoxin-induced leucocyte and protein infiltration, nitric oxide (NO), prostaglandin (PG)-E2 and tumour necrosis factor (TNF)-alpha concentrations in rat aqueous humour, as well as on the cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) protein expression in a mouse macrophage cell line (RAW 264.7 cells) were studied. EIU was induced in male Lewis rats by a footpad injection of lipopolysaccharide (LPS). Immediately after the LPS injection, either 0.1, 1 or 10mgkg(-1) of fucoxanthin was injected intravenously. The aqueous humour was collected 24hr later from both eyes, and both the number of cells infiltrating into the aqueous humour and the aqueous humour protein concentration were measured. The levels of PGE2, NO and TNF-alpha were determined by enzyme-linked immunosorbent assay. The RAW 264.7 cells were pretreated with various concentrations of fucoxanthin for 24hr and subsequently incubated with LPS for 24hr. COX-2 and iNOS protein expression was analysed by the Western blotting method. Levels of PGE2, NO and TNF-alpha production were determined. Fucoxanthin suppressed the development of EIU in a dose-dependent fashion. Treatment with fucoxanthin resulted in a reduction in PGE2, NO and TNF-alpha concentrations in the aqueous humour. The expression of COX and iNOS protein in the fucoxanthin treated RAW264.7 cells decreased significantly compared to that the LPS group. It also significantly reduced the concentration of PGE2, NO and TNF-alpha production in the medium of cells. The present result indicate fucoxanthin suppresses the inflammation of EIU by blocking the iNOS and COX-2 protein expression and its anti-inflammatory effect on eye is comparable with the effect of predinisolone used in similar doses.     

超声提取裙带菜中岩藻黄素的工艺研究

目的运用超声提取法对裙带菜Undaria pinnatifida中岩藻黄素的提取工艺进行研究。方法以HPLC法检测岩藻黄素的量,通过单因素实验考察了提取溶剂、乙醇体积分数、提取时间、提取液料比、提取温度对岩藻黄素提取率的影响;并用正交试验得到超声波法提取岩藻黄素的最佳工艺。结果超声提取的最佳工艺是：乙醇体积分数为90%,超声时间为30min,提取温度为40℃,液料比10∶1。此条件下测得岩藻黄素的提取量为1.362mg/g。结论裙带菜中岩藻黄素的含量丰富,超声法提取岩藻黄素操作简单、方便快捷。     

Fucoxanthin treatment inhibits nasopharyngeal carcinoma cell proliferation through induction of autophagy mechanism

Nasopharyngeal carcinoma (NPC) arises from the epithelium of the nasopharyngeal mucosa. Elderly people above the age of 65 years are more susceptible to NPC. Nasopharyngectomy is the renowned treatment procedure to NPC; however, it is too risky due to its complicated surgical procedure. Other treatment methods also reported with serious side effects such brain injury; hence, the alternative anticancer drug without any side effects was needed. Fucoxanthin is a carotenoid derived from marine algae with the numerous pharmacological functions. This study aims to examine the inhibitory potential in NPC cell proliferation via apoptosis and autophagy. The cytotoxicity of fucoxanthin on C666‐1 cells was observed by the MTT assay. The expression of autophagy‐linked proteins was assessed with immunoblotting analysis. The expression of autophagy protein LC3 was estimated using immunocytochemical analysis in C666‐1 and GFP‐LC3 transfected cells. Furthermore, the fucoxanthin‐treated C666‐1 cells were analyzed with TUNEL assay. The apoptotic level in the fucoxanthin‐treated C666‐1 cells was evaluated using acridine orange staining. Fucoxanthin significantly increased the expression of autophagy‐linked proteins which is clearly depicted in the immunoblotting analysis and immunocytochemical analysis of GFP‐tagged LC3 protein. The results of TUNEL assay of fucoxanthin‐treated C666‐1 in the presence autophagy inhibitors demonstrated the induction of autophagy by fucoxanthin. Acridine orange staining results of C666‐1 confirmed fucoxanthin decreases the expression of autophagy‐linked proteins during stressed condition thereby causes apoptosis. Our overall results authentically conclude that fucoxanthin induces autophagy and apoptosis in NPC cell line, and it can be ideal agent to treat nasopharyngeal cancer in future with further investigations.     

Effect of Fucoxanthin Alone and in Combination with D‐glucosamine Hydrochloride on Carrageenan/kaolin‐induced Experimental Arthritis in Rats

The objective of the present study was to investigate the effect of the fucoxanthin (FUCO) alone and in combination with glucosamine hydrochloride (GAH) on carrageenan/kaolin‐induced inflammatory arthritis model in rats and to explore its underlying mechanisms. Joint swelling, muscle weight ratio (%), histopathological examination and scoring, and proteoglycan degradation were examined. Pro‐inflammatory interleukin (IL‐1β) and tumor necrosis (TNF‐α) levels, cyclooxygenase‐2 (COX‐2), and inducible nitric oxide synthase(iNOS) protein expression and nitric oxide (NO) level in knee synovial tissue extract were analyzed using enzyme‐linked immunosorbent assay, western blotting analysis, and Griess reagent assay, respectively. FUCO and FUCO + GAH not only may significantly reduce degrees of knee joint swelling and prevent against muscle atrophy, but also may significantly attenuate inflammation in synovial tissue, cartilage erosion, and proteoglycan loss. The efficacies of FUCO + GAH were stronger than that of GAH or FUCO. FUCO alone and FUCO + GAH can significantly inhibit upregulation of COX‐2 and iNOS protein expressions, decrease of IL‐1β and TNF‐α levels, and reduce NO production in knee synovial tissue extract. These results indicated that FUCO is an effective anti‐arthritis agent through an antiinflammation mechanism. FUCO may enhance therapeutic effect of GAH on rat arthritis through mechanism of antiinflammation. Copyright © 2013 John Wiley & Sons, Ltd.     

Anti-Cancer Mechanism and Possibility of Nano-Suspension Formulation for a Marine Algae Product Fucoxanthin

Recently, use of natural products available from marine sources, and especially algae products, are receiving more attention. Scientific evidence for claimed nutraceutical and therapeutical effects of one such marine algae product, fucoxanthin, is discussed in this paper with a summary of the currently available literature regarding its antioxidant, anti-obesity and anticancer activities. It is safe for use in humans, but as it has poor solubility a nano-suspension mode of delivery may be adopted to improve efficacy of supplments. We conclude from ourliterature review that the marine algae product fucoxanthin has significant antioxidant, anti-obesity and anticancer activity with established mechanisms of action.