Antioxidant, antitumor, and anti-inflammatory activity of natural products obtained from the brown alga Cystoseira usneoides

Macroalgae are an inexhaustible source of natural products that display a variety of pharmacological and biological activities. Among marine algae, the genus Cystoseira has proven to produce a wide variety of secondary metabolites that could benefit human health. However, studies on the natural products of the species Cystoseira usneoides and their respective biological properties are scarce. Hence, in this thesis, the extract of the brown alga Cystoseira usneoides and the natural products isolated therefrom were tested for antioxidant, anticancer, and antiinflammatory activities. The extract of C. usneoides exhibited potent radical-scavenging and inhibited the proliferation of HT-29 cancer cells by inducing apoptotis and G2/M arrest of the cell cycle. The extract was also found to inhibit the production of TNF-α in LPS-stimulated THP-1 human macrophages. The chemical study of the extract yielded six known algal meroterpenoids (AMTs): usneoidone Z (1), 11-hydroxy-1´-O-methylamentadione (2), cystomexicone B (3), cystomexicone A (4), 6-cis-amentadione-1′-methyl ether (5), and amentadione-1′-methyl ether (6), together with six new compounds: cystodiones A-F (7-12). AMTs 1-10 showed radical-scavenging activity in the ABTS assay. The most active were compounds 5, 6, 7, and 8, which exhibited antioxidant capacity equal or superior to that of the Trolox standard. AMTs 1-8 displayed significant cytotoxic activity against HT-29 human colon cancer cells, whereas lower cytotoxicity was observed against non-tumor cells CCD 841 CoN. Flow cytometry analysis revealed that AMTs 2, 3, and 5 caused apoptosis in HT-29 cells and compounds 1, 2, 3, 4, 5, and 7 induced cell cycle arrest in G2/M phase. Furthermore, AMTs 1-8 also inhibited the migration and invasion of colon cancer cells. Interestingly, exposure of HT-29 cells to different concentrations of AMTs 1-8 correlated with the down-regulation of p-ERK, p-JNK, and p-AKT pathways. Regarding to the anticancer effect of AMTs 1-8 against A549 human lung cancer cells, the cytotoxicity of all compounds was selective for A549 cells when compared to the non-tumor MRC-5 cells. Moreover, treatment of A549 cancer cells with AMTs 1-8 also led to cell cycle arrest in S and G2/M phases. In the in vitro anti-inflammatory assays, AMTs 1-8 showed significant activity as inhibitors of the production of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, COX-2 and iNOS in LPSstimulated THP-1 human macrophages. The in vivo study clearly demonstrated that the compound 11-hydroxy-1´-O-methylamentadione (AMT-E, 2) significantly ameliorated DSS colitis (seven days), including the reduction of weight loss, disease activity, macroscopic and microscopic colonic injury. The levels of TNF-α, IL-1β, IL-10, COX-2 and iNOS expression were also significantly decreased in AMT-E treated DSS colitis. Taken together, these findings strengthen the potential of the natural products isolated from C. usneoides as leads for novel antioxidant, anticancer, and anti-inflammatory agents

A new Leach protocol based on ICH-Leach for adaptive image transferring using DWT

Nowadays, the rapid development and the miniaturization of CMOS image sensors in the last years allowed the creation of WMSN (Wireless Multimedia Sensor Network). Therefore, transferring images through the network becomes an important field of research. The main goal is to transmit the data from a sensor node to another to reach finally the Sink node. Thus, routing protocols play an important role in managing and optimizing the node's resources particularly the energy consumption. Therefore, some routing protocols are known by their ability to save energy and extend the lifetime of the network such as Leach protocol and derived variants. However, multimedia content transferring was not a priority for these protocols. In this paper, the main idea is to adapt ICH-Leach [1], for image transferring. This protocol was tested in a previous work and has given good performances against Leach [2], balanced Leach [3] and MLD-Leach [4]. In fact, the Haar wavelet transform is used, in the application layer, to extract the resolution level to be used in image transmission, depending on the rate flow between the sensor node and the sink node. This paper provides statistics concerning the lifetime of the network, the energy consumption and statistics related to receive images using the peak signal-to-noise ratio (PSNR). The Castalia framework is used for simulation, obtained results show the efficiency of the proposed approach by network lifetime extending and more images transmitting with better quality compared to other protocols

Leach routing protocol for image transfer using Castalia simulator

International audienceIn multimedia wireless sensor network, a routing protocol plays an important role in saving the limited resources of sensors. It allows a node to transmit a multimedia content, an image in our case, to the sink. In this paper, we are going to use the Castralia simulator to test different configurations of leach routing protocol. The aim of these tests is to determine how we can transmit the biggest number of images through network with minimum energy consumption

Anticancer Activities of Meroterpenoids Isolated from the Brown Alga Cystoseira usneoides against the Human Colon Cancer Cells HT-29

Colorectal cancer (CRC) is one of the most common types of cancers and a leading cause of cancer death worldwide. The current treatment for CRC mainly involves surgery, radiotherapy, and chemotherapy. However, due to the side effects and the emergence of drug resistance, the search for new anticancer agents, pharmacologically safe and effective, is needed. In the present study, we have investigated the anticancer effects of eight algal meroterpenoids (AMTs, 1-8) isolated from the brown seaweed Cystoseira usneoides and their underlying mechanisms of action using HT-29, a highly metastatic human colon cancer cell line. All the tested meroterpenoids inhibited the growth of HT-29 malignant cells and were less toxic towards non-cancer colon cells, with the AMTs 1 and 5 exhibiting selectivity indexes of 5.26 and 5.23, respectively. Treatment of HT-29 cells with the AMTs 1, 2, 3, 4, 5, and 7 induced cell cycle arrest in G2/M phase and, in some instances, apoptosis (compounds 2, 3, and 5). Compounds 1-8 also exhibited significant inhibitory effects on the migration and/or invasion of colon cancer cells. Mechanistic analysis demonstrated that the AMTs 1, 2, 5, 6, 7, and 8 reduced phosphorylation levels of extracellular signal-regulated kinase (ERK) and the AMTs 2, 3, 4, 5, 7, and 8 decreased phosphorylation of c-JUN N-terminal kinase (JNK). Moreover, the AMTs 1, 2, 3, 4, 7, and 8 inhibited phosphorylation levels of protein kinase B (AKT) in colon carcinoma cells. These results provide new insights into the mechanisms and functions of the meroterpenoids of C. usneoides, which exhibit an anticancer effect on HT-29 colon cancer cells by inducing cell cycle arrest and apoptosis via the downregulation of ERK/JNK/AKT signaling pathways

Visualization of hyperspectral images on parallel and distributed platform: Apache Spark

The field of hyperspectral image storage and processing has undergone a remarkable evolution in recent years. The visualization of these images represents a challenge as the number of bands exceeds three bands, since direct visualization using the trivial system red, green and blue (RGB) or hue, saturation and lightness (HSL) is not feasible. One potential solution to resolve this problem is the reduction of the dimensionality of the image to three dimensions and thereafter assigning each dimension to a color. Conventional tools and algorithms have become incapable of producing results within a reasonable time. In this paper, we present a new distributed method of visualization of hyperspectral image based on the principal component analysis (PCA) and implemented in a distributed parallel environment (Apache Spark). The visualization of the big hyperspectral images with the proposed method is made in a smaller time and with the same performance as the classical method of visualization

Spectral Classification of a Set of Hyperspectral Images using the Convolutional Neural Network, in a Single Training

International audienceHyperspectral imagery has seen a great evolution in recent years. Consequently, several fields (medical, agriculture, geosciences) need to make the automatic classification of these hyperspectral images with a high rate and in an acceptable time. The state-of-the-art presents several classification algorithms based on the Convolutional Neural Network (CNN) and each algorithm is training on a part of an image and then performs the prediction on the rest. This article proposes a new Fast Spectral classification algorithm based on CNN, and which allows to build a composite image from multiple hyperspectral images, then trains the model only once on the composite image. After training, the model can predict each image separately. To test the validity of the proposed algorithm, two free hyperspectral images are taken, and the training time obtained by the proposed model on the composite image is better than the time obtained from the model of the state-of-the-art

Arabic Text Summarization Challenges using Deep Learning Techniques: A Review

Text summarization is a challenging field in Natural Language Processing due to language modelisation and used techniques to give concise summaries.  Dealing with Arabic language does increase the challenge while taking into consideration the many features of the Arabic language, the lack of tools and resources for Arabic, and the Algorithms adaptation and modelisation. In this paper, we present several researches dealing with Arabic Text summarization applying different Algorithms on several Datasets. We then compare all these researches and we give a conclusion to guide researchers on their further work

Meroterpenoids from the Brown Alga Cystoseira usneoides as Potential Anti-Inflammatory and Lung Anticancer Agents

The anti-inflammatory and anticancer properties of eight meroterpenoids isolated from the brown seaweed Cystoseira usneoides have been evaluated. The algal meroterpenoids (AMTs) 1-8 were tested for their inhibitory effects on the production of the pro-inflammatory cytokines tumor necrosis factor (TNF-alpha), interleukin-6 (IL-6), and interleukin-1 beta (IL-1 beta), and the expression of cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in LPS-stimulated THP-1 human macrophages. The anticancer effects were assessed by cytotoxicity assays against human lung adenocarcinoma A549 cells and normal lung fibroblastic MRC-5 cells, together with flow cytometry analysis of the effects of these AMTs on different phases of the cell cycle. The AMTs 1-8 significantly reduced the production of TNF-alpha, IL-6, and IL-1 beta, and suppressed the COX-2 and iNOS expression, in LPS-stimulated cells (p < 0.05). The AMTs 1-8 displayed higher cytotoxic activities against A549 cancer cells than against MRC-5 normal lung cells. Cell cycle analyses indicated that most of the AMTs caused the arrest of A549 cells at the G2/M and S phases. The AMTs 2 and 5 stand out by combining significant anti-inflammatory and anticancer activities, while 3 and 4 showed interesting selective anticancer effects. These findings suggest that the AMTs produced by C. usneoides may have therapeutic potential in inflammatory diseases and lung cancer

The Algal Meroterpene 11-Hydroxy-11-O-Methylamentadione Ameloriates Dextran Sulfate Sodium-Induced Colitis in Mice

Inflammatory bowel disease (IBD) is a complex class of immune disorders. Unfortunately, a treatment for total remission has not yet been found, while the use of natural product-based therapies has emerged as a promising intervention. The present study was aimed to investigate the anti-inflammatory effects of the algal meroterpene 11-hydroxy-11-O-methylamentadione (AMT-E) in a murine model of dextran sodium sulphate (DSS)-induced colitis. AMT-E was orally administered daily (1, 10, and 20 mg/kg animal) to DSS treated mice (3% w/v) for 7 days. AMT-E prevented body weight loss and colon shortening and effectively attenuated the extent of the colonic damage. Similarly, AMT-E increased mucus production and reduced myeloperoxidase activity (marker for anti-inflammatory activity). Moreover, the algal meroterpene decreased the tumor necrosis factor (TNF)- , interleukin (IL)-1 , and IL-10 levels, and caused a significant reduction of the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Our results demonstrate the protective effects of AMT-E on experimental colitis, provide an insight of the underlying mechanisms of this compound, and suggest that this class of marine natural products might be an interesting candidate for further studies on the prevention/treatment of IBD

Repurposing anticancer drugs for the management of COVID-19

Since its outbreak in the last December, coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has rapidly spread worldwide at a pandemic proportion and thus is regarded as a global public health emergency. The existing therapeutic options for COVID-19 beyond the intensive supportive care are limited, with an undefined or modest efficacy reported so far. Drug repurposing represents an enthusiastic mechanism to use approved drugs outside the scope of their original indication and accelerate the discovery of new therapeutic options. With the emergence of COVID-19, drug repurposing has been largely applied for early clinical testing. In this review, we discuss some repurposed anticancer drugs for the treatment of COVID-19, which are under investigation in clinical trials or proposed for the clinical testing.info:eu-repo/semantics/publishedVersio