Ultrasonic-Assisted Extraction of Fucoxanthin from Marine Macroalga Padina australis:Optimization,Bioactivity,and Structural Characterization

Macroalgae serve as a potential feedstock for fucoxanthin extraction.Fucoxanthin,a bioactive pigment found in the chloroplasts of marine algae,exhibits significant pharmacological properties.As a member of the carotenoid family,fucoxanthin plays a crucial role in both the food and pharmaceutical industries.This research explores the effects of ultrasonics on the extraction of fucoxanthin from the marine macroalga Padina australis.In addition,various extraction techniques and the influence of solvents on the efficient separation of fucoxanthin from algae have been studied and compared.Using methanol,chloroform,and a combination of methanol and chloroform(1:1,v/v),conventional fucoxanthin extraction from Padina australis yielded 8.12 mg of fucoxanthin per gram of biomass.However,the ultrasonic-assisted extraction resulted in a significantly higher yield of 16.9 mg of fucoxanthin per gram of biomass,demonstrating that the use of ultrasonics enhances the extraction rate compared to conventional methods.Therefore,the efficient separation of fucoxanthin from Padina australis is highly dependent on ultrasonic-assisted extraction.The process conditions for the extraction were optimized to maximize the yield of fucoxanthin from seaweeds.The following parameters were selected for optimization studies:moisture content,particle size,mixing speed,extraction temperature,extraction duration,and solid-to-solvent ratio.The extracted fucoxanthin exhibited various biological activities,including antimicrobial and antioxidant properties,and its structure was elucidated through FTIR and NMR spectroscopy.Additionally,thin-layer chromatography of the crude algae extracts confirmed the presence of fucoxanthin in the marine algae.Given these findings,the optimized extraction process holds the potential for scaling up to large-scale fucoxanthin production.Fucoxanthin,as a potent pharmacological agent,offers promising applications in the treatment of various ailments.

褐藻提取物fucoxanthin抑制小鼠S_(180)移植性实体瘤生长及对小鼠免疫功能的影响

目的:研究褐藻提取物fucoxanthin对小鼠S180移植性实体瘤生长的作用及对其免疫功能的影响。方法:观察fucox-anthin(剂量为5,10,20 mg/kg体重)对小鼠S180移植性实体瘤瘤重及脾、胸腺脏器指数的影响;采用碳粒廓清法和DNFB诱导迟发性变态反应实验观察fucoxanthin(5,10,20 mg/kg体重)对正常小鼠免疫功能的作用。结果:fucoxanthin能明显抑制小鼠S180移植性实体瘤的生长,中、高剂量组移植性实体瘤重量分别为(0.63±0.43)g和(0.23±0.12)g,均显著低于模型对照组瘤重量(1.10±0.56)g(P<0.01)。fucoxanthin中、高剂量组的抑瘤率分别为42.7%和79.1%,且呈现剂量相关性。fucoxanthin对S180荷瘤小鼠胸腺指数的影响并无显著意义,但是高剂量的fucoxanthin却使S180荷瘤小鼠的脾指数下降,与模型对照组相比具有显著性差异(P<0.05);同时fucoxanthin对正常小鼠的廓清指数K、吞噬指数α和脾、胸腺指数以及DNFB诱导迟发性变态反应实验中小鼠耳肿胀度的影响均无显著意义。结论:fucoxanthin能明显抑制小鼠S180移植性实体瘤的生长,且呈现剂量相关性,提示其具有有效的体内抗实体瘤生长的作用。fucoxanthin对S180荷瘤小鼠胸腺指数及正常小鼠的免疫功能影响均无显著意义,但是高剂量的fucoxanthin却使S180荷瘤小鼠的脾指数下降,反而抑制其免疫功能,提示fucoxanthin可能并非是通过提高机体免疫功能,而是通过机体内其它生物学途径而发挥其抗肿瘤作用。

Inhibitory activities of microalgal fucoxanthin againstα-amylase,α-glucosidase, and glucose oxidase in 3T3-L1cells linked to type 2 diabetes

Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion and glucose absorption,making them key targets for many studies to treat postprandial hyperglycemia.We studied the inhibitory activities of microalgal fucoxanthin against rat-intestinalα-glucosidase and pancreaticα-amylase along with the antidiabetic eff ect to induce diff erentiation in 3T3-L1 pre-adipocytes using Oil Red-O staining.Fucoxanthin displayed strong hindrance activities towardα-amylase in a concentration-dependent manner,with an IC50 value of 0.68mmol/L,whereas weak inhibitory activity against α-glucosidase,with an IC 50 value of 4.75 mmol/L.Fucoxanthin also considerably elevated glucose oxidase activity in 3T3-L1 cells by 31.3%at 5μmol/L.During adipocyte differentiation,fucoxanthin showed lipid accumulation in 3T3-L1 cells with no cytotoxicity up to 20μmol/L.However,fucoxanthin had no inhibitory activity on glucose-6-phosphate dehydrogenase.These results suggest that fucoxanthin might be useful for the prevention of obesity or diabetes by inhibiting carbohydrate-hydrolyzing enzymes and lipid accumulation and be utilized as an ingredient for a functional food or dietary supplement.

Fucoxanthin Isolated from Undaria pinnatifida Can Interact with Escherichia coli and lactobacilli in the Intestine and Inhibit the Growth of Pathogenic Bacteria

Fucoxanthin is a xanthophyll-type carotenoid that provides many benefits to human health. However, the mechanism by which fucoxanthin interacts with microbes and inhibits pathogenic bacteria is unknown. In this study, we investigated the effects of fucoxanthin isolated from the edible seaweed Undaria pinnatifida on pathogenic bacteria Escherichia coli and lactobacilli both in vitro and in vivo. Fucoxanthin strongly inhibited the growth of Gram-positive pathogenic bacteria but was less effective against Gram-negative bacteria. Fucoxanthin extracted from the crude mixture had a recovery rate of 93.38% and a purity of 82.70%, which were higher than those of fucoxanthin extracted using a previous method. Fucoxanthin also promoted the growth of intestinal mi- crobes in mice. Fucoxanthinol, a metabolite of fucoxanthin, was generated in the culture media. Fucoxanthin can be deacetylated into fucoxanthinol not only by conventional digestive enzymes in the digestive tract, but also by E. coli and lactobacilli in the intestine. These results indicate that fucoxanthin interacts with and influences E. coli and lactobacilli in the intestine. Therefore, fucoxanthin isolated from Undaria pinnatifida possibly can be applied in human health maintenance.

A comparative analysis of fatty acid composition and fucoxanthin content in six Phaeodactylum tricornutum strains from diff erent origins

Phaeodactylum tricornutum is a potential livestock for the combined production of eicosapentaenoic acid(EPA) and fucoxanthin. In this study, six marine diatom strains identified as P. tricornutum were cultured and their total lipid, fatty acid composition and major photosynthetic pigments determined. It was found that the cell dry weight concentration and mean growth rate ranged between 0.24–0.36 g/L and 0.31–0.33/d, respectively. Among the strains, SCSIO771 presented the highest total lipid content, followed by SCSIO828, and the prominent fatty acids in all strains were C16:0, C16:1, C18:1, and C20:5(EPA). Polyunsaturated fatty acids, including C16:2, C18:2, and EPA, comprised a significant proportion of the total fatty acids. EPA was markedly high in all strains, with the highest in SCSIO828 at 25.65% of total fatty acids. Fucoxanthin was the most abundant pigment in all strains, with the highest in SCSIO828 as well, at 5.50 mg/g. The collective results suggested that strain SCSIO828 could be considered a good candidate for the concurrent production of EPA and fucoxanthin.

<i>In Vivo</i>Antioxidant Activity of Fucoxanthin on Obese/Diabetes KK-<i>A^y</i>Mice

Dietary intake of 0.1% fucoxanthin significantly reduced lipid hydroperoxide levels of liver and abdominal white adipose tissue (WAT) of obese/diabetes KK-Ay mice. The fucoxanthin supplementation also significantly reduced blood glucose level and hepatic lipid contents of the mice. Oxidative stress is known to be induced in hyperglycemia and high fat conditions. Therefore, in vivo antioxidant activity of fucoxanthin found in the present study could be attributed to its anti-diabetic effect and its decreasing effect on hepatic lipids. On the other hand, little effect of fucoxanthin on lipid hydroperoxide levels was found in normal ICR mice. Although the content of fucoxanthin metabolites in the abdominal WAT of KK-Ay mice was about 50 times higher that in the liver, there was little difference in its In Vivo antioxidant activity between in the liver and in the abdominal WAT. These results suggest that well-known ability of fucoxanthin to scavenge active oxygen species and/or free radicals would not be a main reason to explain its In Vivo antioxidant activity.

Fucoxanthin suppresses OxLDL-induced inflammation via activation of Nrf2 and inhibition of NF-κB signaling

Objective:To explore the impact of fucoxanthin on oxidized low-density lipoprotein(OxLDL)-induced stress and inflammation in human endothelial cells and its underlying mechanisms.Methods:HUVECs were treated with OxLDL and/or fucoxanthin for a range of time points and concentrations.We evaluated the effects of fucoxanthin on OxLDL-induced HUVECs using the MTT assay,reactive oxygen species accumulation assay,ELISA,RT-PCR,immunofluorescence,and Western blotting.Results:Fucoxanthin enhanced the cell viability in a dose dependent manner after OxLDL exposure.Furthermore,fucoxanthin pretreatment significantly decreased OxLDL-induced reactive oxygen species production and prevented the activation of the nuclear factor kappa-B pathway,which led to substantial suppression of pro-inflammatory gene expressions.OxLDL-induced upregulation of interleukin-6,intercellular adhesion molecule-1,vascular cell adhesion molecule-1,interleukin-1β,monocyte chemotactic protein-1,cyclooxygenase-1,and tumor necrosis factor-αwas significantly reduced by fucoxanthin.Conclusions:Fucoxanthin can inhibit OxLDL-induced vascular inflammation and oxidative stress in HUVECs by targeting Nrf2 signaling pathways.

Dual antidiabetic and antihypertensive activity of fucoxanthin isolated from Sargassum wightii Greville in in vivo rat model

In a previous study from our laboratory, fucoxanthin purified from brown algae, Sargassum wightii Greville has found to exhibit antioxidant activity and inhibition of angiotensin-I-converting enzyme(ACE)in vitro. The present study aims in understanding the protective effect of fucoxanthin purified from S. wightii against diabetes with hypertension in in vivo. Diabetes and hypertension were induced in rat by streptozotocin and sodium chloride treatment, respectively. In diabetes with hypertension rat, the blood pressure was increased along with hyperglycemia. Administration of fucoxanthin significantly reduced the blood pressure and ACE activity in diabetes with hypertension rat. Furthermore, administration of fucoxanthin significantly reduced the hyperglycemic state. The activity of various enzymes in the liver(hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase and fructose-1,6-phosphatase)and serum(creatine kinase)were normalized to that of control level. The level of glycogen, glycoprotein component and lipid profile were equivalent to control level by fucoxanthin administration in diabetes with hypertension rats. Fucoxanthin ameliorated the oxidative stress by preserving the endogenous antioxidant levels in diabetes with hypertension rats. Also, the pancreatic histological integrity was similar to that of control level in diabetes with hypertension rats by fucoxanthin treatment. Altogether, fucoxanthin showed dual antidiabetic and antihypertensive activity in vivo.

Effect of Sargassum filipendula Fucoxanthin against HeLa Cell and Lymphocyte Proliferation

This study aims to （1） obtain a pure extract of Sargassumfilipendula fucoxanthin, （2） determine the effect of concentration of fucoxanthin against HeLa cells, and （3） determine the effect of concentration of fucoxanthin against cancer cell lymphocytes. The benefit of this research is to find out that fucoxanthin can be used as an anti-cancer treatment. The study was conducted in September 2013 at the Laboratory of Fishery Product Technology FPIK UB and UB Medical Biomedical Laboratories, Malang. Sampling brown seaweed （Sargassum filipendula） of the District Rural Padike Talango Sumenep Madura. Extracted isolated by column chromatography using silica gel stationary phase and mobile phase hexane：ethyl acetate （6：4, v/v） ± 100 mL, then identified by TLC using the stationary phase, a silica gel F-254 HPLC with ODS stationary phase （C-18） 5 mL with a mobile phase of methanol, acetone and ammonium acetate （IM） （80：10：10, v/v） and a flow rate of 1.0 mL/min pigment solution of 20 mL compared with the standard of Japan. Research results indicate that, spectra maximum wavelength of 450 nm and 446 nm with a minimum of acetone solvent. HPLC has the same retention time = 10.12 standard, namely Sargassum filipendula = 10.11. By giving some of the best concentrations at 100 ppm is lethal HeLa cells ebesar 5236% which means that fucoxanthin effect against HeLa cells have the potential fucoxanthin that can induce cell apoptosis that occurs in HeLa cells, it is possible because of the anti-carcinogenic fucoxanthin mempuyai structure unique. While the cell lymphocytes in the dosage of 100 ppm were dead at 8.788%, the effect of the toxicity of a substance can be observed from how many dead lymphocytes when compared with the state charity by observing level of lymphocyte proliferation.

Isolation of Fucoxanthin from the Rhizoid of Laminariajaponica Aresch

Fucoxanthin was extracted from the intact rhizoid of Laminariajaponica Aresch with dimethyl sulfoxide （DMSO）, and then recovered from the DMSO extract by partitioning into ethyl acetate and subsequent evaporation. Some isolation conditions such as solvent volume and extraction time were screened. The quantity and quality of the extracted fucoxanthin were determined by spectral analysis （absorption spectra and fluorescence emission spectra）. The results indicated that： （1） the average total content of fucoxanthin was 122.1μg in 1 g of fresh L. japonica rhizoid; （2） in comparison with the widely used organic solvent, acetone, DMSO was much more effective for the extraction of fucoxanthin; （3） both DMSO volume and extraction time influenced extraction efficiency such as the recovery rate and purity of fucoxanthin （1 g of fresh L. japonica rhizoid treated with 4 mL DMSO for 60 min, yielded 〉 88% of the total fucoxanthin with purity 0.63）; （4） when （NH4）2SO4 concentration was in the range of 0.5-1.0 mol/L, the pigments rapidly and entirely moved from DMSO into the ethyl acetate phase; （5） the ethyl acetate and DMSO were recycled using a rotary evaporator.

Isolation of fucoxanthin from Sargassum thunbergii and preparation of microcapsules based on palm stearin solid lipid core

The objective of this study was to isolate fucoxanthin from Sargassum thunbergii and develop microcapsules with palm stearin as the solid lipid core for stability and efficient oral delivery of fucoxanthin. The microcapsules had smooth surfaces with the volume weighted mean diameter （d4.3） of 19.19 μm. Encapsulation efficiency and loading capacity of microcapsules with fucoxanthin were 98.3% and 0.04%, respectively. Moreover, the fucoxanthin in microcapsules presented higher stability than free fucoxanthin against light, humidity and temperature. Especially, the retention rates of fucoxanthin encapsulated in microcapsules reached 97.20% at 4℃, 92.60% at 25℃, 92.32% with the relative humidity of 33% and 92.60% in the dark. The cumulative amount of fucoxanthin released from microcapsules was 22.92% in simulated gastric fluid （SGF） and 56.55% in simulated intestinal fluid （SIF）.

Multi-omics Analyses Provide Insight into the Biosynthesis Pathways of Fucoxanthin in Isochrysis galbana

Isochrysis galbana is considered an ideal bait for functional foods and nutraceuticals of humans because of its high fucoxanthin(Fx)content.However,multi-omics analysis of the regulatory networks for Fx biosynthesis in I.galbana has not been reported.In this study,we report a high-quality genome assembly of I.galbana LG007,which has a genome size of 92.73 Mb,with a contig N50 of 6.99 Mb and 14,900 protein-coding genes.Phylogenetic analysis confirmed the monophyly of Haptophyta,with I.galbana sister to Emiliania huxleyi and Chrysochromulina tobinii.Evolutionary analysis revealed an estimated divergence time between I.galbana and E.huxleyi of~133 million years ago.Gene family analysis indicated that lipid metabolism-related genes exhibited significant expansion,including IgPLMT,IgOAR1,and IgDEGS1.Metabolome analysis showed that the content of carotenoids in I.galbana cultured under green light for 7 days was higher than that under white light,andβ-carotene was the main carotenoid,accounting for 79.09%of the total carotenoids.Comprehensive multi-omics analysis revealed that the content ofβ-carotene,antheraxanthin,zeaxanthin,and Fx was increased by green light induction,which was significantly correlated with the expression of IgMYB98,IgZDS,IgPDS,IgLHCX2,IgZEP,IgLCYb,and IgNSY.These findings contribute to the understanding of Fx biosynthesis and its regulation,providing a valuable reference for food and pharmaceutical applications.

Excited State Properties of Fucoxanthin Aggregates

The structure and excited state properties of the H- and J-aggregates of the marine carbonyl carotenoid, fucoxanthin(Fx), were studied by various spectroscopic methods, and compared with those of Fx monomers in polar organic solvents. The fluorescent analysis indicated tliat the higher vibronic states of S2 contribute more to populating the S1 state, from which fluorescent emission mainly originates. Resonance Raman and density functional theory calculations confirmed the ‘card-packed' and chead-to-taiF structures of the H- and J-aggregates of Fx, respectively. An fs time-resolved absorption study proved the coexistence of Si and intramolecular charge transfer relaxation pathways upon excitation to the S2 state for both tlie monomers and aggregates.

Cultivation of Anabena variabilis,Synechococcus elongatus,Spirulina platensis for the production of C-Phycocyanin,C-Phycoerythrin and Thalassiosira,Skeletonema,Chaetoceros for fucoxanthin

The pigments are vital parts of photosynthetic machinery in algae and exhibit a myriad of applications as nutraceuticals,cosmetics,colorants,which find huge applications in many industires,including the paint industry and paper industry.The antimicrobial,antioxidative,anti-inflammatory,and anti-cancer potential of microalgal pigments contribute towards their varied industrial applications.In this study,pigments(Fucoxanthin,C-phycocyanin,and C-phycoerythrin),extracted from microalgae were investigated to check the antimicrobial efficacy using agar well diffusion and disc diffusion methods against pathogenic bacteria:Staphylococcus aureus and Escherichia coli.The fucoxanthin pigment isolated from diatom Thalassiosira sp.exhibited the highest antibacterial activity against Staphylococcus aureus(17±1.53 mm)and in contrast fucoxanthin pigment isolated from Chaetoceroes sp.exhibited the highest bactericidal activity against Escherichia coli(18±1).The pigment extract of Spirulina plantesis showed the highest antibacterial activity against E.coli(41±0.3)and S.elongatus also exhibited high antibacterial activity against E.coli(32±0.5)while Anabaena variabilis showed the highest antibacterial activity against Staphylococcus aureus(34±0.5).The potential of microalgal pigments is highly valuable and further extensive studies can elaborate the underlying mechanisms.

尿苷二磷酸葡萄糖促进三角褐指藻岩藻黄素积累的研究

岩藻黄素(Fucoxanthin)是自然界中丰富的类胡萝卜素,为提高微藻中岩藻黄素的含量,本实验主要通过叶绿素荧光参数法、高效液相色谱法等探究了外源添加不同浓度的尿苷二磷酸葡萄糖(UDPG)对三角褐指藻光合作用能力及岩藻黄素含量的影响。研究表明,150μmol/L UDPG显著提高了三角褐指藻的光合作用能力,促进了三角褐指藻中岩藻黄素积累,其含量达到(9.57±0.81)mg/g,比对照组提高了161.76%。此外,硅甲藻黄素、硅藻黄素、β-胡萝卜素、紫黄质、叶绿素a和叶绿素c 2的含量分别比对照组提高了84.31%、79.73%、164.74%、123.04%、358.35%和2260.09%。研究结果表明,外源添加150μmol/L UDPG可显著促进三角褐指藻积累岩藻黄素。

岩藻黄质活化核因子E2相关因子2改善糖皮质激素诱导的成骨细胞凋亡

背景:骨质疏松症发病率高,易导致骨折等并发症的发生,而现有药物干预不良反应大,难以满足临床需求。目的:探索岩藻黄质对糖皮质激素诱导成骨细胞骨质疏松症模型的作用与潜在机制。方法:将原代大鼠成骨细胞接种于6孔板内,待细胞融合度达到80%后分4组干预:对照组单纯培养24 h,糖皮质激素组使用地塞米松干预24 h,岩藻黄质组使用岩藻黄质干预24 h,糖皮质激素+岩藻黄质组使用地塞米松与岩藻黄质同时干预24 h。干预结束后,检测细胞增殖、凋亡、细胞内活性氧含量以及凋亡相关蛋白、骨形成相关蛋白、细胞核核因子E2相关因子2的蛋白表达。结果与结论:①CCK-8检测显示,与对照组比较,糖皮质激素组细胞活性降低(P<0.05);与糖皮质激素组比较,糖皮质激素+岩藻黄质组细胞活性升高(P<0.05);②JC-1线粒体膜电位染色与流式细胞学检测显示,与对照组比较,糖皮质激素组细胞凋亡比例增加(P<0.05);与糖皮质激素组比较,糖皮质激素+岩藻黄质组细胞凋亡比例减少(P<0.05);③Western Blot检测显示,与对照组比较,糖皮质激素组BAX、裂解聚ADP核糖聚合酶的蛋白表达升高(P<0.05),BCL2、Ⅰ型胶原蛋白α1肽链、碱性磷酸酶、骨钙蛋白、RUNX2的蛋白表达降低(P<0.05);与糖皮质激素组比较,糖皮质激素+岩藻黄质组BAX、裂解聚ADP核糖聚合酶的蛋白表达降低(P<0.05),BCL2、Ⅰ型胶原蛋白α1肽链、碱性磷酸酶、骨钙蛋白、RUNX2的蛋白表达升高(P<0.05);④荧光探针检测显示,与对照组比较,糖皮质激素组活性氧含量增加(P<0.05);与糖皮质激素组比较,糖皮质激素+岩藻黄质组活性氧含量减少(P<0.05);⑤免疫荧光染色与Western Blot检测显示,与对照组比较,糖皮质激素组细胞核核因子E2相关因子2的蛋白表达降低(P<0.05);与糖皮质激素组比较,糖皮质激素+岩藻黄质组细胞核核因子E2相关因子2的蛋白表达升高(P<0.05);⑥结果表明,岩藻黄质通过活化核因子E2相关因子2改善糖皮质激素诱导的成骨细胞凋亡与骨形成相关分子表达。

An axenic strain reveals the responses of Phaeodactylum tricornutum to external organic carbon

The model diatom Phaeodactylum tricornutum is considered a promising source of various high value bioproducts,and developing cultivation processes is crucial for its commercialization.Although mixotrophy and heterotrophy have been recommended as effective strategies for microalgal cultivation,previous studies on P.tricornutum have yielded conflicting results in terms of cultivating this microalga.To verify the capacity of this microalga utilizing external organic carbon,both heterotrophic and mixotrophic cultivation with varied carbon sources were performed using an axenic strain.The results demonstrate that glycerol was the only organic carbon that substantially stimulated the growth of P.tricornutum in the presence of light.Sodium acetate(NaAc)at low concentrations could also promote growth,while at high concentrations led to severe inhibition under mixotrophic conditions.The addition of glucose imposed no appreciable impact on either cell density or biomass concentration,confirming that P.tricornutum cannot metabolize external glucose.Subsequently,a comparative analysis between mixotrophy and autotrophy was performed to reveal the influences of glycerol on the cellular metabolism based on growth performances,biochemical compositions,and chlorophyll fluorescence parameters.Results also indicate that the addition of glycerol did not have detrimental effects on the capacity of either pigments biosynthesis or photosynthesis,but enhanced the saturated fatty acids and reduced the unsaturated fatty acids.

不同光周期对湛江等鞭金藻生长、岩藻黄素含量和光合作用及相关基因表达的影响

为研究不同光周期对湛江等鞭金藻(Isochrysis zhanjiangensis)细胞生长和岩藻黄素含量的影响,及其光合作用和基因表达调控机理,本研究测定了5种光周期条件下湛江等鞭金藻岩藻黄素、叶绿素含量和叶绿素荧光参数,利用实时荧光定量聚合酶链式反应(RTq-PCR)研究光合作用和岩藻黄素合成关键酶基因表达水平。结果表明,18L∶6D光周期条件下,湛江等鞭金藻细胞生长最快。当光周期为12L∶12D时,湛江等鞭金藻岩藻黄素产量最高,为4.35 mg·L^(-1)。当光周期为6L∶18D时,湛江等鞭金藻单位细胞岩藻黄素含量最高,为0.33 mg·10^(5)cells^(-1),与光周期12L∶12D、18L∶6D和24L∶0D相比分别提高了5.3%、39.1%和63.5%(P<0.01)。光合生理指标结果表明,随着光周期时间的增加,湛江等鞭金藻叶绿素含量及叶绿素荧光参数中PSⅡ实际光合量子产率Y(Ⅱ)和非光化学淬灭系数(qP)呈下降趋势,与岩藻黄素含量的变化趋势一致。RTq-PCR结果表明,随着光周期时间的增加,湛江等鞭金藻Rubisco酶大亚基基因(rbcL)、八氢番茄红素脱氢酶基因(pds)、番茄红素β-环化酶基因(lcyb)和玉米黄素环氧酶基因3(zep3)表达呈下降趋势,与岩藻黄素含量的变化趋势一致,说明光周期可能通过rbcL、pds、lcyb和zep3调控岩藻黄素合成。光周期通过调控光合作用和岩藻黄素生物合成相关基因表达影响湛江等鞭金藻中岩藻黄素的积累。本研究为提高湛江等鞭金藻中的岩藻黄素含量提供了理论依据。

岩藻黄素的抗炎、抗癌活性及作用机制研究进展

岩藻黄素(Fucoxanthin)是一种类胡萝卜素,呈红褐色,主要来源于褐藻和硅藻等海洋生物,因其独特的化学结构和丰富的生物活性而引起了广泛的科研兴趣。研究表明,岩藻黄素具有显著的抗炎和抗癌活性,其抗炎作用机制主要包括抑制氧化应激、调控炎症因子、诱导细胞自噬和抵抗细胞凋亡等,抗癌作用机制主要包括诱导细胞自噬与凋亡机制、调控细胞周期、抑制细胞迁移和细胞侵袭等多个方面。本文对岩藻黄素的抗炎、抗癌活性及相关作用机制的研究进展进行简要概述,为进一步深入研究及开发岩藻黄素提供理论基础和借鉴。

岩藻黄质通过AKT/mTOR途径调节糖酵解代谢促进人急性淋巴细胞白血病细胞凋亡的作用研究

为阐明岩藻黄质促进人急性淋巴细胞白血病(CEM/C1)细胞凋亡的作用机制,本研究采用MTT法检测岩藻黄质处理后的CEM/C1细胞活力;利用流式细胞仪测定CEM/C1细胞的早期与晚期凋亡率以及细胞周期的分布;采用试剂盒检测岩藻黄质对CEM/C1细胞中丙酮酸激酶(PK)和己糖激酶(HK)活性以及葡萄糖摄取量、三磷酸腺苷(ATP)生成量、乳酸生成量的影响;通过蛋白免疫印迹法(WB)测定CEM/C1细胞相关蛋白表达水平,并通过分子对接进行验证。结果表明,岩藻黄质对CEM/C1细胞活力具有显著的抑制效果,并呈剂量和时间依赖性;随着岩藻黄质浓度的增加,CEM/C1细胞的早期凋亡率和晚期凋亡率明显增加,G1/G2细胞的比例显著或极显著下降,S期细胞的比例显著或极显著上升;岩藻黄质显著抑制糖酵解相关酶(PK、HK)的活性以及蛋白表达;岩藻黄质显著降低磷酸化mTOR和磷酸化AKT蛋白的表达水平;岩藻黄质与AKT和mTOR蛋白对接的结合能均小于-5 kcal·mol^(-1),主要通过氢键作用于酶活中心。综上,岩藻黄质能显著促进CEM/C1细胞凋亡,其作用机制可能与AKT/mTOR信号通过调控的糖酵解有关。研究结果为羊栖菜高附加值产品开发及天然、安全抗白血病药物前体的筛选提供了一定的理论依据。