心肌缺血再灌注损伤模型大鼠经艾塞那肽预处理后心肌细胞的凋亡

背景：有研究表明艾塞那肽可改善心肌梗死和心力衰竭等过程发挥心血管保护作用,但其对缺血再灌注损伤后心肌细胞凋亡的作用尚未阐明。 目的：艾塞那肽预处理心肌缺血再灌注损伤模型大鼠,观察其对心肌组织细胞凋亡及对凋亡因子Bcl-2、Bax表达的影响。 方法：建立心肌缺血再灌注损伤模型大鼠,用艾塞那肽进行预处理,并设缺血再灌注组和假手术组作对照。 结果与结论：免疫组织化学染色、原位末端标记检测RT-PCR检测显示,与缺血再灌注组比较,艾塞那肽组Bcl-2的mRNA和蛋白表达显著升高(P < 0.05),Bax mRNA和蛋白表达显著降低(P < 0.05),心肌细胞凋亡指数显著降低(P < 0.05)。结果证实,艾塞那肽对大鼠心肌缺血再灌注有保护作用,其机制可能是通过上调Bcl-2的表达,下调Bax的表达,从而抑制心肌细胞凋亡有关。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程     

远隔缺血后处理对脑缺血模型大鼠再灌注损伤炎性反应相关信号的影响

背景：虽然目前已有一些研究表明远隔缺血后处理可以发挥神经保护作用,但是具体的机制尚不明了。 目的：探讨远隔缺血后处理对大鼠局灶性脑缺血再灌注损伤的保护作用。 方法：应用线栓法制备大鼠大脑中动脉闭塞局灶性脑缺血再灌注模型,并进行远隔缺血后处理,同时设假手术组和缺血再灌注组作对照。于缺血再灌注24 h后进行神经功能评分,检测梗死体积及脑含水量;RT-PCR检测缺血周围区脑组织内白细胞介素1β、白细胞介素6、肿瘤坏死因子α和单核细胞趋化蛋白1 mRNA表达情况;Western blot检测Bcl-2和Bax蛋白表达情况。 结果与结论：与缺血再灌注组相比,远隔缺血后处理组神经功能评分有所降低,但差异无显著性意义,梗死范围和脑组织含水量显著降低(P < 0.05)。远隔缺血后处理组与缺血再灌注组相比,大鼠缺血周围区脑组织白细胞介素1β、白细胞介素6、肿瘤坏死因子α、单核细胞趋化蛋白1 mRNA和Bax蛋白表达降低(P < 0.05),Bcl-2蛋白表达升高(P < 0.05)。结果证实,远隔缺血后处理可以减轻大鼠局灶性脑缺血再灌注产生的损伤,其机制可能与减轻炎性反应有关。  中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程     

骨髓间充质干细胞静脉移植脊髓损伤大鼠肿瘤坏死因子α及 白细胞介素1β的表达

背景：研究认为间充质干细胞的营养支持在脊髓损伤治疗中起了主要作用,其同损伤宿主神经组织间的相互作用可导致一些不利于损伤修复的炎症因子表达减少。 目的：观察大鼠骨髓间充质干细胞静脉注射移植对脊髓损伤后肿瘤坏死因子α、白细胞介素1β 表达的影响。 方法：运用改良Allen法制备大鼠T10脊髓外伤性截瘫模型,随机分为对照组和骨髓间充质干细胞移植组,设未损伤脊髓的假手术组做对照。骨髓间充质干细胞移植组、假手术组均接受大鼠骨髓间充质干细胞静脉注射移植,对照组静脉注射等量PBS。 结果与结论：对照组和骨髓间充质干细胞移植组损伤脊髓肿瘤坏死因子α、白细胞介素1β蛋白表达较假手术组有明显增加(P < 0.05);骨髓间充质干细胞移植组与对照组比较, 肿瘤坏死因子α、白细胞介素1β蛋白表达受到明显抑制(P < 0.05)。提示大鼠骨髓间充质干细胞静脉移植后能使损伤脊髓局部的肿瘤坏死因子α、白细胞介素1β表达程度降低。这可能是改变脊髓损伤区的微环境,减少脊髓继发性损伤,促进损伤大鼠运动功能恢复的机制之一。     

嗅鞘细胞移植脊髓全横断损伤大鼠大脑皮质运动区转化生长因子β表达的影响

背景：多项研究已证实嗅鞘细胞能促进脊髓损伤大鼠神经功能的恢复,但其分子机制还不清楚。 目的：观察嗅鞘细胞移植对脊髓全横断大鼠大脑皮质运动区转化生长因子β mRNA表达的影响。 方法：采用酶消化法培养GFP转基因小鼠嗅鞘细胞,制成细胞悬液。建立SD大鼠T9脊髓全横断模型,造模后分为假手术组、模型组和嗅鞘细胞移植组。应用RT-PCR方法检测各组大鼠大脑皮质运动区转化生长因子β mRNA的表达变化,用β-actin作内参。 结果与结论：模型组大鼠造模后3 d大脑皮质运动区转化生长因子β mRNA的表达量高于假手术组(P < 0.05),造模后7,14,21和28 d回到假手术组水平。嗅鞘细胞移植后21 d,嗅鞘细胞移植组转化生长因子β mRNA的表达量低于模型组(P < 0.05)。提示全横断脊髓损伤致大脑皮质运动区转化生长因子β mRNA早期表达上调,随后与假手术组相比无差别;嗅鞘细胞移植后期可逆转转化生长因子β mRNA的表达变化,有助于脊髓损伤的恢复。     

缺血后处理局灶性脑缺血再灌注模型大鼠相关通路以及白细胞介素8的表达

背景：缺血后处理能够激发内源性保护作用,抑制缺血再灌注后的炎症反应,但具体机制目前尚不明确。目的：观察缺血后处理对局灶性脑缺血再灌注大鼠Toll样受体4-核因子κB信号转导通路以及白细胞介素8表达的影响,进一步阐述缺血后处理的神经保护机制。方法：将110只大鼠随机分为假手术组10只、模型组和缺血后处理组各50只,将大鼠按照Zea-Longa法建立局灶性脑缺血再灌注模型,再进行缺血后处理,即大脑中动脉闭塞2 h后进行3个循环的再灌注15 s/缺血15 s,设模型组和假手术组作对照。对各组进行神经行为学评分,TTC染色测定脑梗死体积,免疫组织化学法检测脑组织Toll样受体4、核因子кB和白细胞介素8蛋白表达,原位杂交法检测其mRNA表达。结果与结论：模型组、缺血后处理组大鼠都出现神经行为学缺失及缺血侧大脑半球梗死。再灌注6,12,24,48,72 h,与模型组相比,缺血后处理组大鼠神经行为学评分显著改善(P < 0.05)、脑梗死体积明显减少(P < 0.05)。模型组和缺血后处理组Toll样受体4、核因子кB、白细胞介素8蛋白和mRNA表达于再灌注6 h时已升高,24 h达峰值。再灌注6,12,24,48,72 h,与模型组各对应时间点亚组比较,缺血后处理组上述各因子表达均显著降低(P < 0.05)。结果证实,缺血后处理可抑制缺血再灌注引起的炎症反应,通过抑制Toll样受体4-核因子κB信号转导通路和下调白细胞介素8的表达,以此发挥神经保护作用。  中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程     

NF-κB参与低氧预适应对自体原位肝移植大鼠JNK通路的影响

背景：在肝脏缺血再灌注损伤中,NF-κB与JNK通路的串扰方式决定了细胞的死亡或存活。而将低氧预适应用于肝移植过程所导致的细胞凋亡现象,尚未见有报道。 目的：探讨低氧预适应后NF-κB的表达对移植肝JNK通路的影响及保护作用。 方法：采用经门静脉灌注法建立大鼠自体原位肝移植模型,SD大鼠随机分为正常对照组：不接受任何处理;自体移植组：行自体原位肝移植;低氧预适应组：移植前体积分数8%氮氧混合气体的低氧预处理90 min,然后行自体原位肝移植。分别于移植后 1,6,24 h处死大鼠取肝脏标本检测肝组织丙二醛、超氧化物歧化酶水平,免疫组化方法测定大鼠肝组织p-JNK蛋白,RT-PCR检测肝脏 NF-κB mRNA含量,透射电子显微镜下观察肝细胞的超微结构变化。 结果与结论：与对照组比较,两移植组肝组织丙二醛水平升高,超氧化物歧化酶水平降低(P < 0.05);与自体移植组比较,低氧预适应组丙二醛水平显著降低、超氧化物歧化酶水平显著升高(P < 0.05)。与正常对照组比较,两移植组各时相p-JNK蛋白的表达、NF-κB mRNA的转录水平显著升高 (P <0.05);与自体移植组比较,低氧预适应组NF-κB mRNA转录水平显著增高(P < 0.05),p-JNK蛋白的表达明显降低(P < 0.05)。透射电镜下自体移植组肝细胞出现典型的凋亡征象,而低氧预适应组肝细胞无明显凋亡形态。提示,肝移植大鼠低氧预适应后可能通过上调NF-κB的表达,减少活性氧释放,抑制JNK通路的持续激活,从而抑制肝细胞凋亡,减轻肝脏缺血再灌注。     

右美托咪定抑制肾缺血/再灌注炎性反应

背景：在缺血/再灌注肾脏损伤的防治研究中,用药物激活或抑制机体某些因子从而保护肾组织,对肾移植和移植物的功能恢复有着重要意义。 目的：探索右美托咪定对大鼠肾缺血/再灌注炎性因子及C-X-C型趋化因子受体4表达的影响。 方法：40只大鼠随机等分为假手术组、缺血再灌注组、右美托咪定预处理组及右美托咪定后处理组。后3组行右肾切除,左肾缺血45 min,再灌注60 min,造肾缺血再灌注模型;右美托咪定预处理组于大鼠股静脉穿刺置管后泵注1 μg/kg右美托咪定,10 min后改为0.5 μg/kg,泵注30 min直至缺血即刻;右美托咪定后处理组于左肾再灌注后静脉泵注0.5 μg/kg右美托咪定 30 min。 结果与结论：肾脏缺血再灌注大鼠肾脏损伤严重,炎症明显,肾小管扩张,有肾小球肾炎表现,血清中白细胞介素1β和肿瘤坏死因子α水平显著升高(P < 0.05),血清和肾脏中C-X-C型趋化因子受体4水平也明显增加(P < 0.05);经右美托咪定预处理或后处理的肾缺血再灌注大鼠血清中白细胞介素1和肿瘤坏死因子α水平明显降低(P < 0.05),血清和肾脏中C-X-C型趋化因子受体4水平也明显降低(P < 0.05)。提示肾缺血再灌注可致以炎性反应为特征的肾损伤;右美托咪定可以抑制炎性反应并弱化C-X-C型趋化因子受体4的表达,具有一定的肾保护作用。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

骨髓间充质干细胞移植大鼠脑缺血区微血管密度和肝细胞生长因子的表达

背景：应用骨髓间充质干细胞移植治疗脑缺血可促进损伤神经功能的恢复,目前其作用机制尚未明确。 目的：分析骨髓间充质干细胞移植对大鼠脑缺血保护作用的机制。 方法：采用线栓法复制大鼠大脑中动脉栓塞模型,随机分为假手术组、大脑中动脉栓塞组、溶剂对照组和骨髓间充质干细胞组。骨髓间充质干细胞组于脑梗死1 d后经侧脑室注射入骨髓间充质干细胞,溶剂对照组则注射同等剂量的PBS。 结果与结论：大鼠脑缺血后缺血区皮质可见大量的微血管生成,2周达高峰。骨髓间充质干细胞组缺血区微血管密度显著高于大脑中动脉栓塞组和溶剂对照组(P < 0.01)。治疗后4,7,14 d骨髓间充质干细胞组脑组织中肝细胞生长因子的表达水平显著高于大脑中动脉栓塞组和溶剂对照组(P < 0.01)。提示骨髓间充质干细胞移植可促进大鼠缺血区微血管生成,改善缺血区血运,从而改善脑缺血大鼠的神经功能。     

紫癜性肾炎患者外周血单个核细胞Toll样受体3和4的信号转导途径

背景：目前关于Toll样受体3和Toll样受体4介导的信号转导通路在紫癜性肾炎的发病机制中的作用尚不清楚。目的：分析Toll样受体3和Toll样受体4在过敏性紫癜和紫癜性肾炎发病机制中的作用。方法：选取过敏性紫癜患儿64例,分为过敏性紫癜无肾损害组36例及过敏性紫癜性肾炎组28例,另选健康儿童30例作为正常对照组。实时荧光定量PCR检测外周血单核细胞Toll样受体3、Toll样受体4、髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6、白细胞介素12 mRNA的基因相对表达量;应用流式细胞术检测外周血单核细胞Toll样受体3、Toll样受体4蛋白表达率。结果与结论：①过敏性紫癜患儿Toll样受体4 mRNA及蛋白表达显著高于正常对照组(P < 0.05)。紫癜性肾炎组Toll样受体4 mRNA及蛋白表达均显著高于紫癜无肾损害组(P < 0.05)。②过敏性紫癜组髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6 mRNA的表达均显著高于正常对照组(P < 0.05),白细胞介素12 mRNA的表达显著低于正常对照组(P < 0.05);紫癜性肾炎组髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6 mRNA的表达显著高于紫癜无肾损害组(P < 0.05),紫癜性肾炎组白细胞介素12 mRNA的表达显著低于紫癜无肾损害组(P < 0.05)。③过敏性紫癜组患儿外周血单核细胞Toll样受体4 mRNA与蛋白表达呈正相关(r=0.60,P < 0.01);过敏性紫癜患儿Toll样受体4 mRNA与髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6表达均呈正相关(P < 0.01),与白细胞介素12 mRNA表达呈负相关(r=-0.66,P < 0.01)。提示Toll样受体4可能通过髓样细胞分化因子88依赖信号转导途径介导过敏性紫癜的免疫发病机制,Toll样受体4的过度活化可能与过敏性紫癜的肾损伤有关。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

骨髓间充质干细胞移植促进脑缺血性损伤大鼠神经细胞黏附分子的表达

背景：骨髓间充质干细胞移植能促进神经功能修复,其作用机制可能与上调神经细胞黏附分子有关。 目的：观察骨髓间充质干细胞移植对急性脑缺血损伤大鼠神经细胞黏附分子表达的影响。 方法：将SD大鼠按随机数字表法分为假手术组和模型组。模型组大鼠采用线栓法制作大脑中动脉阻塞模型,再随机分为细胞移植组(左侧侧脑室移植同种异体骨髓间充质干细胞5×10⁵)和对照组(移植磷酸盐缓冲液)。假手术组不闭塞大脑中动脉也不移植。 结果与结论：移植后7,14 d,细胞移植组与对照组梗死灶周围神经细胞黏附分子表达高于假手术组(P < 0.01),且细胞移植组高于对照组(P < 0.05)。移植后14 d,细胞移植组神经功能缺损评分明显低于对照组(P < 0.05)。说明骨髓间充质干细胞移植后通过上调局灶性脑缺血大鼠脑梗死灶周神经细胞黏附分子表达促进神经功能的恢复。     

Astaxanthin limits exercise-induced skeletal and cardiac muscle damage in mice

Dietary antioxidants may attenuate oxidative damage from strenuous exercise in various tissues. Beneficial effects of the antioxidant astaxanthin have been demonstrated in vitro, but not yet in vivo. We investigated the effect of dietary supplementation with astaxanthin on oxidative damage induced by strenuous exercise in mouse gastrocnemius and heart. C57BL/6 mice (7 weeks old) were divided into groups: rested control, intense exercise, and exercise with astaxanthin supplementation. After 3 weeks of exercise acclimation, both exercise groups ran on a treadmill at 28 m/min until exhaustion. Exercise-increased 4-hydroxy-2-nonenal-modified protein and 8-hydroxy-2'-deoxyguanosine in gastrocnemius and heart were blunted in the astaxanthin group. Increases in plasma creatine kinase activity, and in myeloperoxidase activity in gastrocnemius and heart, also were lessened by astaxanthin. Astaxanthin showed accumulation in gastrocnemius and heart from the 3 week supplementation. Astaxanthin can attenuate exercise-induced damage in mouse skeletal muscle and heart, including an associated neutrophil infiltration that induces further damage.     

产虾青素酿酒酵母工程菌的构建

目的 对酿酒酵母固有的β-胡萝卜素代谢途径进行扩展,构建能够合成虾青素的酿酒酵母工程菌。 方法 对不同来源的虾青素合成基因 crtZ（β-胡萝卜素羟化酶）与 crtW （β-胡萝卜素酮化酶）进行随机组合,采用overlap PCR 技术构建串联表达质粒,并将其导入产β-胡萝卜素酿酒酵母工程菌内,发酵产物经 HPLC 和 UPLC-MS鉴定,确定其成分。 结果 构建出8种 TEF1p-crtZ-ADH1t-PGK1P-crtW-CYC1t组合的串联表达模式,其中基因组合分别为 crtZ1-crtW1, crtZ1-crtW4工程菌 HCCB08571、HCCB08572产生了虾青素;工程菌 HCCB08566、HCCB08568、HCCB08573未检测到产物虾青素,而出现了中间产物玉米黄质和斑蝥黄质。 结论 成功构建了产生虾青素及其中间体的酿酒酵母工程菌。     

Antiproliferation and induction of cell death of Phaffia rhodozyma (Xanthophyllomyces dendrorhous) extract fermented by brewer malt waste on breast cancer cells

Astaxanthin has been shown to have antiproliferative activity on breast cancer and skin cancer cells. However, the high cost of production, isolation and purification of purified astaxanthin from natural sources or chemically synthetic methods limit its usage on cancer therapy. We show that astaxanthin could be produced by fermentating the Phaffia rhodozyma (Xanthophyllomyces dendrorhous) yeast cells with brewer malt waste using a 20 L B. Braun fermentor. The percentage composition of astaxanthin from the P. rhodozyma was >70% of total pigment as estimated by the high performance liquid chromatographic analysis. Furthermore, the antiproliferative activity of this P. rhodozyma cell extract (PRE) was demonstrated on breast cancer cell lines including the MCF-7 (estrogen receptor positive) and MDA-MB231 (estrogen receptor negative) by using the [3-(4,5-dimethylthiazol-2-yl)-5-(3-arboxymethoxyphenyl)-2- (4-sulfophenyl)-2H-tetrazolium] (MTS) assay. No apoptotic cell death, but growth inhibitory effect was induced after 48 h of PRE incubation as suggested by morphological investigation. Anchorage-dependent clonogenicity assay showed that PRE could reduce the colony formation potential of both breast cancer cell lines. Cell death was observed from both breast cancer cell lines after incubation with PRE for 6 days. Taken together, our results showed that by using an economic method of brewer malt waste fermentation, we obtained P. rhodozyma with a high yield of astaxanthin and the corresponding PRE could have short-term growth inhibition and long-term cell death activity on breast cancer cells.     

Effect of astaxanthin and melatonin on cell viability and DNA damage in human breast cancer cell lines

BackgroundAstaxanthin is a xanthophyll pigment found in algae and marine animals, having strong anti-oxidative, anti-tumoral, and anti-inflammatory effects. Additionally, melatonin has shown inhibitory effects on the growth of human breast cancer cells. The aim of the present study was to evaluate the effect of astaxanthin and the combined effects of astaxanthin and melatonin on breast cancer cells and the non-tumoral breast cell line.Materials and methodsThe human breast cancer cell lines, T47D and MDA-MB-231, and non-tumorigenic cell line MCF 10A were treated and compared to astaxanthin, melatonin, and co-administration of these two compounds. Cell viability, apoptosis induction, Bcl-2 protein expression, and DNA damage were measured by MTT assay, acridine orange/ethidium bromide (AO/EB) staining, immunocytochemistry, and comet assay.ResultsAstaxanthin at lower doses than melatonin reduced cell viability and Bcl2 expression, induced apoptosis and DNA damage in MDA-MB-231 and T47D. Meanwhile, the effects of astaxanthin on cell cytotoxicity, apoptosis, and DNA damage in MCF10A cells are insignificant compared to MDA-MB-231 and T47D. Moreover, the results indicated that astaxanthin in T47D cells caused more cell death compared to MDA-MB-231 cells. Astaxanthin induced cell death on breast cancer cells and without cell cytotoxicity for non-cancerous cells.ConclusionFurthermore, the presence of astaxanthin increased the function of melatonin-induced cell death in breast cancer cells.     

Possible immunomodulating activities of carotenoids in in vitro cell culture experiments

Immunomodulating activities of β-carotene and carotene-associated carotenoids such as canthaxanthin (β,β-carotene-4,4 dione) and astaxanthin (3,3′-dihydroxyl β,β-carotene 4,4-dione) were analyzed by in vitro cell culture experiments. (i) β-Carotene, canthaxanthin and astaxanthin caused significant stimulatory effects on the cell proliferative response of spleen cells and thymocytes from BALB/c mice at the concentrations of 2 × 10⁻⁸ to 10⁻⁷M, although they showed the activities different from each other. (ii) Astaxanthin exhibited the highest activity on the polyclonal antibody (immunoglobulin M and G) production of murine spleen cells at the concentrations of 2 × 10⁻⁸ to 10⁻⁷ M but β-carotene did not cause a significant effect at a low concentration (2 × 10⁻⁸ M) although stimulated at a high concentration (2 × 10⁻⁷M). Canthaxanthin expressed moderate activities at the same concentrations. (iii) All tested carotenoids significantly enhanced the release of interleukin-1 α and tumor necrosis factor-α from murine peritoneal adherent cells at the concentrations of 2 × 10⁻⁹ to 10⁻⁷M and the ranks of cytokine-inducing activities were astaxanthin > canthaxanthin > β-carotene. These results indicate that carotenoids such as β-carotene, canthaxanthin and astaxanthin have possible immunomodulating activities to enhance the proliferation and functions of murine immunocompetent cells.     

Microarray profiling of gene expression patterns in glomerular cells of astaxanthin-treated diabetic mice: a nutrigenomic approach

We have demonstrated that astaxanthin reduces glomerular oxidative stress as well as inhibits the increase in urinary albumin in diabetic db/db mice. The aim of the present study was to determine the gene expression patterns in the glomerular cells of the diabetic mouse kidney, and to investigate the effects of astaxanthin on the expression of these genes using a high-density DNA microarray. The diet administered to the astaxanthin-supplementation group was prepared by mixing a control powder with astaxanthin at a concentration of 0.02%. Glomerular cells were obtained from the kidneys of mice by laser capture microdissection. Preparation of cRNA and target hybridization were performed according to the Affymetrix GeneChip eukaryotic small sample target labeling assay protocol. The gene expression profile was evaluated by the mouse expression set 430A GeneChip. Array data analysis was carried out using Affymetrix GeneChip operating and Ingenuity Pathway analysis software. Comparison between diabetic db/db and non-diabetic db/m mice revealed that 779 probes (3.1%) were significantly affected, i.e. 550 probes were up-regulated, and 229 probes were down-regulated, both at levels of >/=1.5-fold in the diabetic mice. Ingenuity signal analysis of 550 up-regulated probes revealed the mitochondrial oxidative phosphorylation pathway as the most significantly affected caronical pathway. The affected genes were associated with complexes I, III, and IV located on the mitochondrial inner membrane, and the expression levels of these genes were decreased in mice treated with astaxanthin as compared to the levels in the control mice. In addition, the expression of many genes associated with oxidative stress, collagen synthesis, and transforming growth factor-beta signaling was enhanced in the diabetic mice, and this enhancement was slightly inhibited in the astaxanthin-treated mice. In conclusion, this genome-wide nutrigenomics approach provided insight into genes and putative genetic pathways that are thought to be affected by stimulation by high-glucose concentrations. In addition, the present approach may help us gain a better understanding of the genes and pathways involved in the anti-diabetic mechanism of astaxanthin.     

Lipid profile and glucose changes after supplementation with astaxanthin: a systematic review and meta-analysis of randomized controlled trials

Introduction

Many studies have shown that oral supplementation with astaxanthin may be a novel potential treatment for inflammation and oxidative stress in cardiovascular diseases, but evidence of the effects on lipid profile and glucose is still inconclusive. Therefore, we performed a meta-analysis to evaluate the efficacy of astaxanthin supplementation on plasma lipid and glucose concentrations.

Material and methods

The search included PubMed, Cochrane Library, Scopus, and EMBASE (up to November 27, 2014) to identify randomized controlled trials (RCTs) investigating the effects of astaxanthin supplementation on lipid profile and glucose levels. Two independent reviewers extracted data on study characteristics, methods and outcomes.

Results

Seven studies meeting inclusion criteria with 280 participants were selected for this meta-analysis; 163 participants were allocated to the astaxanthin supplementation group and 117 to the control group. A random-effect meta-analysis of data from 7 RCTs (10 treatment arms) did not show any significant effect of supplementation with astaxanthin on plasma concentrations of total cholesterol (weighted mean difference (WMD): –1.52 mg/dl, 95% CI: –8.69 to –5.66, p = 0.679), LDL-C (WMD: +1.25 mg/dl, 95% CI: –6.70 to +9.21, p = 0.758), HDL-C (WMD: +1.75 mg/dl, 95% CI: –0.92 to +4.42, p = 0.199), triglycerides (WMD: –4.76 mg/dl, 95% CI: –21.52 to +12.00, p = 0.578), or glucose (WMD: –2.65 mg/dl, 95% CI: –5.84 to +0.54, p = 0.103). All these effect sizes were robust, and omission of any of the included studies did not significantly change the overall estimate.

Conclusions

This meta-analysis of data from 10 RCT arms did not indicate a significant effect of supplementation with astaxanthin on plasma lipid profile, but a slight glucose-lowering effect was observed. Further, well-designed trials are necessary to validate these results.     

Effect of antioxidants on the immune response of Helicobacter pylori

Antioxidants are substances capable of inhibiting oxidation. In chronic diseases, inflammatory response cells produce oxygen free radicals. Oxygen free radicals cause DNA damage, and this may lead to gene modifications that might be carcinogenic. Chronic Helicobacter pylori infection causes the production of DNA-damaging free radicals. In recent years, various groups have studied the effects of antioxidants, especially on H. pylori -associated gastric cancer. In most of the studies, it has been shown that H. pylori infection does affect the level of antioxidants measured in the gastric juice, but there are also controversial results. Recent experimental studies, both in vivo and in vitro, have shown that vitamin C and astaxanthin, a carotenoid, are not only free radical scavengers but also show antimicrobial activity against H. pylori. It has been shown that astaxanthin changes the immune response to H. pylori by shifting the Th1 response towards a Th2 T-cell response. Very few experimental studies support the epidemiologic studies, and further studies are needed to describe the effect and the mechanism of antioxidants in the H. pylori immune response.     

Astaxanthin supplementation attenuates immobilization-induced skeletal muscle fibrosis via suppression of oxidative stress

Immobilization induces skeletal muscle fibrosis characterized by increasing collagen synthesis in the perimysium and endomysium. Transforming growth factor-β1 (TGF-β1) is associated with this lesion via promoting differentiation of fibroblasts into myofibroblasts. In addition, reactive oxygen species (ROS) are shown to mediate TGF-β1-induced fibrosis in tissues. These reports suggest the importance of ROS reduction for attenuating skeletal muscle fibrosis. Astaxanthin, a powerful antioxidant, has been shown to reduce ROS production in disused muscle. Therefore, we investigated the effects of astaxanthin supplementation on muscle fibrosis under immobilization. In the present study, immobilization increased the collagen fiber area, the expression levels of TGF-β1, α-smooth muscle actin, and superoxide dismutase-1 protein and ROS production. However, these changes induced by immobilization were attenuated by astaxanthin supplementation. These results indicate the effectiveness of astaxanthin supplementation on skeletal muscle fibrosis induced by ankle joint immobilization.     

Protective effects of astaxanthin on subarachnoid hemorrhage-induced early brain injury: Reduction of cerebral vasospasm and improvement of neuron survival and mitochondrial function

The purpose of this study was to evaluate the neuroprotective effects of astaxanthin on early brain injury (EBI) caused by subarachnoid hemorrhage (SAH) in rats and to explore possible molecular mechanisms. Experimental SAH model was introduced in adult male SD rats by injecting autologous arterial blood into the prechiasmatic cistern. Astaxanthin (75?mg/kg bodyweight) or olive oil was administered by oral gavage at 3?h after SAH. Our results showed that astaxanthin attenuated SAH-induced cerebral vasospasm and reduced neuronal apoptosis. Astaxanthin inhibited mitochondria-associated neuron apoptosis in the prefrontal cortex after SAH: increased mitochondrial membrane potential, decreased Bax/Bcl-2 ratio, inhibited cytochrome C release in cytoplasm, and suppressed caspase-3 enzyme activity. Furthermore, the cerebral expression levels of synaptic proteins (Synapsin-1, postsynaptic density-95 and growth-associated protein-43) and nerve growth and neuronal differentiation factors (brain-derived neurotropic factor and purine-rich binding protein-alpha) were reduced following SAH. Astaxanthin partly restored their expression. In conclusion, our current work demonstrates that astaxanthin attenuates SAH-induced EBI, possibly by improving neuronal survival and mitochondrial function.