Antioxidant Bioactivity of Extracts from Beach Cast Leaves of Posidonia oceanica (L.) Delile

The marine environment is a generous source of biologically active compounds useful for human health. In 50 years, about 25,000 bioactive marine compounds have been identified, with an increase of 5% per year. Peculiar feature of algae and plants is the production of secondary metabolites, such as polyphenols, synthesized as a form of adaptation to environmental stress. Posidonia oceanica is a Mediterranean endemic and dominant seagrass and represents a biologically, ecologically and geologically important marine ecosystem. Within this study, methanolic and ethanolic extracts were generated from fresh and dried Posidonia oceanica leaves, with the aim to employ and valorize the beach cast leaves. The best yield and antioxidant activity (polyphenols content equal to 19.712 ± 0.496 mg GAE/g and DPPH IC50 of 0.090 µg/µL.) were recorded in 70% ethanol extracts (Gd-E4) obtained from leaves dried for two days at 60 °C and ground four times. HPLC analyses revealed the presence of polyphenols compounds (the most abundant of which was chicoric acid) with antioxidant and beneficial properties. Bioactive properties of the Gd-E4 extracts were evaluated in vitro using fibroblast cells line (HS-68), subjected to UV induced oxidative stress. Pre-treatment of cells with Gd-E4 extracts led to significant protection against oxidative stress and mortality associated with UV exposure, thus highlighting the beneficial properties of antioxidants compounds produced by these marine plants against photo damage, free radicals and associated negative cellular effects. Beach cast leaves selection, processing and extraction procedures, and the in vitro assay results suggested the potentiality of a sustainable approach for the biotechnological exploitation of this resource and could serve a model for other marine resources.     

Glucose Uptake and Oxidative Stress in Caco-2 Cells: Health Benefits from Posidonia oceanica (L.) Delile

Posidonia oceanica (L.) Delile is an endemic Mediterranean marine plant of extreme ecological importance. Previous in vitro and in vivo studies have demonstrated the potential antidiabetic properties of P. oceanica leaf extract. Intestinal glucose transporters play a key role in glucose homeostasis and represent novel targets for the management of diabetes. In this study, the ability of a hydroalcoholic P. oceanica leaf extract (POE) to modulate intestinal glucose transporters was investigated using Caco-2 cells as a model of an intestinal barrier. The incubation of cells with POE significantly decreased glucose uptake by decreasing the GLUT2 glucose transporter levels. Moreover, POE had a positive effect on the barrier integrity by increasing the Zonulin-1 levels. A protective effect exerted by POE against oxidative stress induced by chronic exposure to high glucose concentrations or tert-butyl hydroperoxide was also demonstrated. This study highlights for the first time the effect of POE on glucose transport, intestinal barrier integrity, and its protective antioxidant effect in Caco-2 cells. These findings suggest that the P. oceanica phytocomplex may have a positive impact by preventing the intestinal cell dysfunction involved in the development of inflammation-related disease associated with oxidative stress.     

An Overview of New Insights into the Benefits of the Seagrass Posidonia oceanica for Human Health

Posidonia oceanica (L.) Delile is a Mediterranean-endemic angiosperm often described for its great ecological importance. Despite evidence of a millennia-old relationship between P. oceanica and humans, as well as traditional medicine applications, the potential benefits of P. oceanica for human health have been documented only recently. This review aims to compile newly acquired knowledge on P. oceanica bioactive properties that allow the scientific community to look at this plant as a promising source of natural therapeutical products for human health. Experimental investigations conducted in both in vitro cellular-based and in vivo animal models pave the way for new research projects aiming at the development of alternative and complementary therapeutic strategies based on P. oceanica against a wide range of pathological conditions.     

Dihydroaustrasulfone Alcohol Inhibits PDGF-Induced Proliferation and Migration of Human Aortic Smooth Muscle Cells through Inhibition of the Cell Cycle

Dihydroaustrasulfone alcohol is the synthetic precursor of austrasulfone, which is a marine natural product, isolated from the Taiwanese soft coral Cladiella australis. Dihydroaustrasulfone alcohol has anti-inflammatory, neuroprotective, antitumor and anti-atherogenic properties. Although dihydroaustrasulfone alcohol has been shown to inhibit neointima formation, its effect on human vascular smooth muscle cells (VSMCs) has not been elucidated. We examined the effects and the mechanisms of action of dihydroaustrasulfone alcohol on proliferation, migration and phenotypic modulation of human aortic smooth muscle cells (HASMCs). Dihydroaustrasulfone alcohol significantly inhibited proliferation, DNA synthesis and migration of HASMCs, without inducing cell death. Dihydroaustrasulfone alcohol also inhibited platelet-derived growth factor (PDGF)-induced expression of cyclin-dependent kinases (CDK) 2, CDK4, cyclin D1 and cyclin E. In addition, dihydroaustrasulfone alcohol inhibited PDGF-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), whereas it had no effect on the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/(Akt). Moreover, treatment with PD98059, a highly selective ERK inhibitor, blocked PDGF-induced upregulation of cyclin D1 and cyclin E and downregulation of p27^kip1. Furthermore, dihydroaustrasulfone alcohol also inhibits VSMC synthetic phenotype formation induced by PDGF. For in vivo studies, dihydroaustrasulfone alcohol decreased smooth muscle cell proliferation in a rat model of restenosis induced by balloon injury. Immunohistochemical staining showed that dihydroaustrasulfone alcohol noticeably decreased the expression of proliferating cell nuclear antigen (PCNA) and altered VSMC phenotype from a synthetic to contractile state. Our findings provide important insights into the mechanisms underlying the vasoprotective actions of dihydroaustrasulfone alcohol and suggest that it may be a useful therapeutic agent for the treatment of vascular occlusive disease.     

儿茶素对ECV304细胞增殖和迁移的影响

利用体外细胞培养技术探讨了四种儿茶素对ECV304细胞增殖和迁移的影响。结果发现,EGCG对ECV304细胞存活率的影响最显著,在EGCG浓度为50~150μmol/L时,细胞存活率达到极显著差异,半数抑制浓度IC50为75~150μmol/L;EGCG对该细胞迁移作用影响明显,且呈剂量依赖性,IC50为150μmol/L,EGCG可能通过抑制内皮细胞的迁移抑制新生血管的生成;ECG与ECV304作用36h和48h,IC50分别为390μmol/L和370μmol/L;C和EC与ECV304作用时,细胞存活率在80%以上。四种儿茶素在浓度低于75μmol/L时,对正常ECV304细胞抑制影响不大。     

Inhibitory Effect of Dihydroaustrasulfone Alcohol on the Migration of Human Non-Small Cell Lung Carcinoma A549 Cells and the Antitumor Effect on a Lewis Lung Carcinoma-Bearing Tumor Model in C57BL/6J Mice

There are many major causes of cancer death, including metastasis of cancer. Dihydroaustrasulfone alcohol, which is isolated from marine coral, has shown antioxidant activity, but has not been reported to have an anti-cancer effect. We first discovered that dihydroaustrasulfone alcohol provided a concentration-dependent inhibitory effect on the migration and motility of human non-small cell lung carcinoma (NSCLC) A549 cells by trans-well and wound healing assays. The results of a zymography assay and Western blot showed that dihydroaustrasulfone alcohol suppressed the activities and protein expression of matrix metalloproteinase (MMP)-2 and MMP-9. Further investigation revealed that dihydroaustrasulfone alcohol suppressed the phosphorylation of ERK1/2, p38, and JNK1/2. Dihydroaustrasulfone alcohol also suppressed the expression of PI3K and the phosphorylation of Akt. Furthermore, dihydroaustrasulfone alcohol markedly inhibited tumor growth in Lewis lung cancer (LLC)-bearing mice. We concluded that dihydroaustrasulfone alcohol is a new pure compound with anti-migration and anti-tumor growth activity in lung cancer and might be applied to clinical treatment in the future.     

Antitumor Effects of a Sesquiterpene Derivative from Marine Sponge in Human Breast Cancer Cells

In this study, the anti-proliferative effect of ilimaquinone, a sesquiterpene derivative from the marine sponge, in breast cancer cells was investigated. Ilimaquinone inhibited the proliferation of MCF-7 and MDA-MB-231 breast cancer cells with IC₅₀ values of 10.6 μM and 13.5 μM, respectively. Non-tumorigenic human breast epithelial cells were less sensitive to ilimaquinone than breast cancer cells. Flow cytometric and Western blot analysis showed that ilimaquinone induced S-phase arrest by modulating the expression of p-CDC-2 and p21. Ilimaquinone induces apoptosis, which is accompanied by multiple biological biomarkers, including the downregulation of Akt, ERK, and Bax, upregulation of p38, loss of mitochondrial membrane potential, increased reactive oxygen species generation, and induced autophagy. Collectively, these findings suggest that ilimaquinone causes cell cycle arrest as well as induces apoptosis and autophagy in breast cancer cells.     

Arthropod communities related to different mixtures of oil (Glycine max L. Merr.) and essential oil (Artemisia annua L.) crops

Plants can host many herbivores and their natural enemies during their growth cycles. For this reason, changes in the relative abundance of crop and weed plants in a monocropping system as well as different crop plants in an intercropping system may produce great bottom up impacts in the specific and functional structure of spontaneous communities of arthropods. The hypothesis of this study was that the combination of two contrasting species, soybean (Glycine max, Fabaceae, N₂ fixing plant) and annual wormwood (Artemisia annua, Asteraceae, VOCs plant), would be related to different spontaneous communities of arthropods depending on the proportion of each species, and this would favor crop biodiversity without compromising crop production. The objectives of the study were: (a) to analyze the differences of spontaneous communities of arthropods related to different soybean (S)-annual wormwood (W) mixtures, using standard crop management for S production in Argentina, (b) to determine S and W total biomass and W essential oil content and yield and, (c) to analyze the relationship between arthropod communities and crop productivity. Factorial field experiments with 3 replications were done during 2006 and 2007. S density was kept constant (40 plants m⁻²) and different W densities (plants m⁻²) were added. Treatments were pure S, S + 2W, S + 4W, S + 8W and pure W (8 plants m⁻²). Arthropods were sampled at soybean full flowering and were classified in functional groups as herbivores and non-herbivores. S and W total and relative biomass and W essential oil content and yield from leaves and inflorescences were estimated in reproductive stage. Arthropod morphospecies abundance and richness were determined for each treatment. Data were analyzed using uni (ANOVA) and multivariate (CCA) techniques. Arthropods belonging to 7 orders presented a total richness of 48 morphospecies in 2006 and 36 in 2007, while total abundance was 379 in 2006 and 318 in 2007. The proportion of non-herbivores was higher than the proportion of herbivores. Different arthropod communities were observed according to each treatment. No differences were found among treatments in S + W and S total biomass production, while W total biomass and essential oil yield were both different among treatments. Relative biomass production of S and W was the main explanatory variable related to the contrast of arthropod communities between pure annual wormwood (W) and the rest of the treatments. Annual wormwood could be used as an accompanying essential oil crop or left as a weed in the densities tested in this work, favoring biodiversity and, eventually, pest management without compromising soybean crop yield.     

长春花4种提取物肝癌细胞毒活性的研究

用溶剂萃取法对长春花地上部分的95%乙醇提取物进行分段处理,以肝癌细胞系SMMC-7721为筛选模型,利用MTT法测定各提取物的体外肿瘤细胞毒活性,对长春花的肝癌细胞毒活性部位进行了筛选。结果表明：长春花乙醇总提取物和正丁醇提取物对体外肝癌细胞表现出较强的抑制活性,石油醚提取物﹑乙酸乙酯提取物和水提取物则没有活性。说明正丁醇提取物部分是长春花体外肝癌细胞毒活性部位。     

自然低温对茶树内源激素含量的影响

以南京中山陵茶园中十年生龙井长叶茶树为试验材料,用酶联免疫法(ELISA)测定自然低温下茶树叶片内源激素含量的变化,以探讨自然低温下茶树内源激素变化规律。结果显示,自然越冬期间,茶树叶片中吲哚乙酸(IAA)含量的波动幅度最大,脱落酸(ABA)次之,而赤霉素(GA_3)与玉米素核苷(ZR)波动幅度较小;同时,除了ABA外,茶树其他内源激素IAA、ZR和GA_3含量变化趋势一致;激素间比值变化和相关性分析显示ZR与GA_3、ZR与IAA、IAA与GA_3含量变化极显著相关,ABA与IAA、ABA与ZR呈显著正相关。试验结果表明,茶树内源激素之间关系密切,茶树可能通过调控ABA/(GA_3+IAA+ZR)的比值来适应自然低温环境。     

Salinity-Induced Ultrastructural Alterations in Leaf Cells of Rice (Oryza sativa L.)

Summary

High concentrations of NaCl significantly reduced the fresh and dry weights and lengths of roots and shoots. NaCl exhibited a more rapid effect in water culture than in soil culture. In both water and solid cultures, root growth was suppressed more severely than shoot growth. Electron microscopic studies revealed that NaCl caused swelling of thylakoids, accumulation of starch grains and lipid droplets, distortion of grana stacking, increase in the size and number of plastoglobuli and vesiculation of cellular membrane. Mitochondria became deficient in cristae, swelled and the matrix appeared pale in salt-treated plants as compared with control plants. Disappearance of nucleolus and nuclear chromatin and destruction of vascular tissues were occasionally observed in salt-treated plants.     

Changes in some nutrients of fenugreek (Trigonella Foenum graecum L.) seeds during water boiling

Fenugreek seeds were boiled in water for various lengths of time (5, 10 and 15 min). Changes in weight, volume, moisture content, total sugars, nitrogen compounds, minerals, phosphorus compounds, phytic acid, amino acids and the in vitro digestibility of the seeds as well as the total solids of the boiling water were determined. Data indicated that there was an increase in both weightand volume as well as the in vitro digetibility of fenugreek seeds especially after the first 5 minutes of boiling. On the other hand, a decrease in the content of total sugars, protein compounds, calcium, magnesium, phytic acid, phosphorus and amino acids was observed. The reduction was accompanied by a gradual increase in the total solids of boiling water.     

花生细胞工程与遗传转化研究进展

花生细胞工程与遗传转化的研究对于花生品种改良、新品种繁育以及种质资源保存等具有重要意兰。对二十世纪90年代以来花生高效再生技术和遗传转化研究的现状以及发展趋势进行概述和讨论。     

Hierridin B Isolated from a Marine Cyanobacterium Alters VDAC1, Mitochondrial Activity,and Cell Cycle Genes on HT-29 Colon Adenocarcinoma Cells

Background: Hierridin B was isolated from a marine cyanobacterium Cyanobium sp. strain and induced cytotoxicity selectively in HT-29 adenocarcinoma cells. The underlying molecular mechanism was not yet elucidated. Methods: HT-29 cells were exposed to the IC₅₀ concentration of hierridin B (100.2 μM) for 48 h. Non-targeted proteomics was performed using 2D gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The mRNA expression of apoptotic and cell cycle genes were analyzed by real-time PCR. Automated quantification of 160 cytoplasm and mitochondrial parameter was done by fluorescence microscopy using CellProfiler software. Results: Proteomics identified 21 significant different proteins, which belonged to protein folding/synthesis and cell structure amongst others. Increase of VDAC1 protein responsible for formation of mitochondrial channels was confirmed by mRNA expression. A 10-fold decrease of cytoskeleton proteins (STMN1, TBCA) provided a link to alterations of the cell cycle. CCNB1 and CCNE mRNA were decreased two-fold, and P21CIP increased 10-fold, indicative of cell cycle arrest. Morphological analysis of mitochondrial parameter confirmed a reduced mitochondrial activity. Conclusion: Hierridin B is a potential anticancer compound that targets mitochondrial activity and function.     

Palmitic Acid and Ergosta-7,22-dien-3-ol Contribute to the Apoptotic Effect and Cell Cycle Arrest of an Extract from Marthasterias glacialis L. in Neuroblastoma Cells

We describe the effect of a chemically characterized lipophilic extract obtained from Marthasterias glacialis L. against human breast cancer (MCF-7) and human neuroblastoma (SH-SY5Y) cell lines. Evaluation of DNA synthesis revealed that both cell lines were markedly affected in a concentration-dependent way, the SH-SY5Y cell line being more susceptible. Cell cycle arrest was observed, an effect induced by the sterol, ergosta-7,22-dien-3-ol, present in the extract. Morphological evaluation of treated cells showed the advent of lipid droplets and chromatin condensation compatible with apoptosis, which was confirmed by the evaluation of caspase-3 and -9 activities. Palmitic acid was the main compound responsible for this apoptotic effect by a ceramide-independent mechanism that involved endoplasmic reticulum (ER)-stress with upregulation of CCAAT/-enhancer-binding protein homologous protein (CHOP).     

Cell and nuclear degradation in root meristems following exposure of potatoes (Solanum tuberosum L.) to salinity

Summary In many plant species, it has been demonstrated at the whole plant level that supplemental Ca²⁺ alleviates the effects of salinity stress. These effects have been attributed to physiological processes, but there are no reports of the effects of supplemental Ca²⁺ on preventing nuclear damage to the root meristematic cells following exposure to NaCl salinity. Two in vitro cultured potato (Solanum tuberosum L.) cultivars, analysed by fluorescent microscopy and flow cytometry, showed a similar pattern of salinity-induced changes to the nuclei of root meristematic cells. Damage occurring after only a few hours was followed by nuclear degradation at 24 h. Flow cytometry histograms showed a reduction in G1 and G2 nuclei and an increase in degraded nuclei, in NaCl-stressed roots. Salinity-induced nuclear degradation was alleviated by the addition of CaCl₂.     

Cell wall mediated bulkiness as related to the texture of potato (Solanum tuberosum L.) tuber tissue

Summary Potato tuber bulkiness was studied in an attempt to elucidate the role of the cell wall (CW) in the tissue texture. The volume of the tissue homogenate was measured before and after enzymatic degradation of insoluble pectic substances (PS) and cellulose. Enzymatic removal of PS resulted in disappearance of the middle lamella ultrastructure, leading to a slight volumetric reduction at most, and both were retained the inner CW and the starch grains in the lumen. Enzymatic degradation of cellulose resulted in the loss of the CW ultrastructure and of the homogenate bulkiness; starch and protoplasmic residues precipitated separately. Among the neutral sugars, starch-glucose was the predominant one (ca. 15% of the fresh weight), and the others were cellulose-glucose, rhamnose, arabinose, xylose, mannose and galactose. The microfibrillar lattice of the cellulose glucan provided the tissue bulkiness and texture. Other factors such as pectin and starch may affect texture through interactions with the microfibrillar lattice of cellulose. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. 1518-E, 1985 series.     

Variations of endoreduplication and its potential contribution to endosperm development in rice (Oryza sativa L.)

ABSTRACT

Endoreduplication is the phenomenon by which cells increase their ploidy. Endoreduplication is initiated by the transition from the mitotic cell cycle to the endocycle, in which DNA replication occurs without a subsequent chromosome separation and cytokinesis, and is enhanced by endocycle reiteration. This process appears to play an important role in endosperm development, but the characteristics of endoreduplication in the endosperm of rice (Oryza sativa) remain unclear. To elucidate the features and variations of endoreduplication in rice endosperm, endoreduplication progression in the developing endosperm was compared among 10 cultivars based on flow cytometry and fluorescence microscopy. The flow cytometric analysis detected significant differences among 10 cultivars in the following three parameters: mean ploidy of all nuclei, the proportion of nuclei ≥6C (%E, an estimate of the initiation of the endocycle), and the mean ploidy of nuclei ≥6C (E6P, an estimate of the reiteration of the endocycle). However, no significant correlation between %E and E6P was observed, suggesting that the initiation and reiteration of the endocycle are independently regulated. Fluorescence microscopy revealed that the ploidy of the nuclei was higher in the intermediate region than in the central and peripheral regions of the endosperm. Cells with a higher ploidy were larger in the developing endosperm. Furthermore, the mean ploidy in the developing endosperm was significantly correlated with the mean cell size in the mature endosperm. These results indicate that endoreduplication progression in the endosperm differed significantly among the 10 rice cultivars and such differences may influence endosperm cell size.     

Phenolic compounds in raw and cooked rice (Oryza sativa L.) and their inhibitory effect on the activity of angiotensin I-converting enzyme

Whole rice has been widely studied due to the abundance of bioactive compounds in its pericarp. Some of the beneficial effects of these compounds on human health have been attributed to their antioxidant and other biological activities, such as enzyme inhibition. In this work, we evaluated the contents of total, soluble and insoluble phenolic compounds of 6 red and 10 non-pigmented genotypes of whole rice as well as their inhibitory effect on the activity of angiotensin I-converting enzyme (ACE). The effects of cooking on phenolics and their inhibitory activities were also investigated. Red genotypes showed high content of phenolics, mainly soluble compounds, at an average of 409.7 mg ferulic acid eq./100 g, whereas overall lower average levels (99.4 mg ferulic acid eq./100 g) at an approximate soluble/insoluble compound ratio of 1:1 were observed in non-pigmented rice. Pigmented rice displayed a greater inhibitory effect on ACE than non-pigmented rice. In fact, a significant correlation between the content of soluble phenolics and ACE inhibition was observed (r = 0.8985, p < 0.05). In addition to significantly reducing the levels of total phenolics and ACE inhibition, cooking altered the soluble/insoluble compound ratio, especially among red rice genotypes.     

Development, growth and chemical composition of the potato crop (solanum tuberosum L.). II. Tuber and whole plant

Summary This second paper of the review describes the development of the potato tuber and whole plant based on research data and literature. The development and growth, daily changes of fresh and dry matter, and of the contents of organic and inorganic components (dry matter, starch, sugars, organic acids, ascorbic acid, nitrogenous compounds, nitrate, crude lipid, glycoalkaloids, P, K, Ca, Mg, Mn, Na), discolouration indices, and physiological parameters (rate of assimilation and respiration, activity of enzymes) are reviewed.