A multiplex metabolomic approach for quality control of Spirulina supplement and its allied microalgae (Amphora & Chlorella) assisted by chemometrics and molecular networking.

Microalgae species are of economic importance regarded as "green gold" being rich in bioactive compounds. Spirulina and Chlorella are the most popular microalgal species and are marketed as healthy food supplements. At the same time, Amphora holds potential as a source of healthy lipids and essential fatty acids. Yet, there are considerable variations in their reported chemical composition, and less is known about their compositional differences. A multiplexed metabolomic approach was adopted for the quality control (QC) of Spirulina supplements and to compare its constitutive metabolome to Chlorella and Amphora. The adopted protocol comprised gas chromatography-mass spectrometry (GC-MS), ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-HRMS/MS), and ultraviolet-visible spectrophotometry (UV/Vis) for mapping their primary and secondary metabolome. Interestingly, UPLC-HRMS/MS analysis delineated the abundance of fatty acids in Amphora versus glycolipids enrichment in Spirulina, and porphyrins were the main pigments identified in Spirulina, with scarce occurrence in Chlorella. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) analysis of GC-MS data set revealed palmitic acid, 3-mannobiose, and glyceryl-glycoside as being most enriched in Spirulina, versus sucrose and leucine in Chlorella and Amphora, respectively. Despite being of low discriminatory potential, UV/Vis OPLS-DA modeling showed that Spirulina was distinguished with the UV absorbances of carotenoids and chlorophyll pigments, as indicated by its OPLS-DA derived S-plot. Our study provides a QC approach for the analysis of the microalgal species and poses alternative spectral and compositional markers for their discrimination.

Ultrasound-induced cell disintegration and its ultrastructure characterization for the valorisation of Chlorella pyrenoidosa protein.

Chlorella pyrenoidosa (CP) has great potential for feeding future demands in food, environment, energy, and pharmaceuticals. To achieve this goal, the exploitation of emerging efficient technique such as ultrasound-assisted extraction (UAE) for CP nutrient enrichment is crucial. Here, UAE is deployed for high-efficient CP protein (CPP) valorisation. Compared to conventional solvent extraction (CSE), remarkable mass transfer enhancements with 9-time protein yields and 3-time extraction rate are achieved by ultrasonic cavitation in UAE, indicating UAE can drastically shift intracellular nutrients including proteins and pigments to solvent. Cell morphology and ultrastructure show the different responses of cell wall and membrane, indicating that the cell membrane may play a role in the extraction process, based on which the extremely-low efficiency of CSE and high efficiency of UAE are highlighted. This study provides a solution for future food crisis by extracting CPP and may open a new discussion field in ultrasonic extraction.

Microalga Chlorella sp. extract induced apoptotic cell death of cholangiocarcinoma via AKT/mTOR signaling pathway.

Cancer is the leading cause of death worldwide. Drug resistance and relapse after current standard treatments frequently occur; thus, alternative and effective treatments are required. Algae and cyanobacteria are abundant organisms that serve as bioresources of nutrients/metabolites, which are attractive sources of numerous bioactive compounds for drug discovery. In the present study, we, therefore, investigated anti-cancer activities of crude polysaccharide and ethanolic extracts from Chlorella sp., Sargassum spp., and Spirulina sp. against cell lines of five top-leading cancers including lung cancer (A549), cervical cancer (Hela), breast cancer (MCF7), hepatocellular carcinoma (Huh7), and cholangiocarcinoma (CCA; KKU213A). Only ethanolic extracts of Chlorella sp. showed consistent inhibition of growth of all cancer cell types. CCA was the most sensitive to Chlorella sp. ethanolic extract with CC50 of 277.4, 400.5, and 313.4 µg/mL for KKU055, KKU100, and KKU213A cells, respectively. Flow cytometric analysis demonstrated that CCA cell death was triggered via apoptosis pathway in accompany with lowering procaspase-3, -8, and -9 and increasing caspase enzymatic activity in addition to reducing anti-apoptosis Bcl-2 protein. Interestingly, the treatment of the extract at 400 µg/mL greatly inhibited the AKT/mTOR survival signaling as evidenced by significant reduction of phosphorylated-AKT and phosphorylated-mTOR proteins. The presence of reported bioactive compounds, gallic acid, and lutein, were confirmed in Chlorella sp. extract by high-performance liquid chromatography. Gallic acid and lutein treatment caused a significant reduction of KKU055, KKU100, and KKU213A cell viability. This study demonstrated the anti-cancer effect of Chlorella sp. ethanolic extract to promote cancer cell death via inhibition of AKT/mTOR pathway.

Process intensification for the enhancement of growth and chlorophyll molecules of isolated Chlorella thermophila: A systematic experimental and optimization approach.

In our current work, we have optimized six physicochemical parameters (light intensity, light period, pH, inoculum size, culture period, and salt concentration) toward growth and chlorophyll synthesis using isolated fresh water microalgae Chlorella thermophila [contains ∼6% (w/w on dry biomass basis) chlorophyll]. Here, both experimental and computational [Taguchi orthogonal array (TOA), artificial neural network (ANN), and genetic algorithm (GA)] approaches were employed for the process intensification. Results revealed that the content of biomass and chlorophyll were enhanced by 118% and 95%, respectively, with productivity enhancement of 30% for biomass and 61% for chlorophyll from the optimization of physicochemical parameters. Further, optimum light intensity was found to be 128 µmol m-2 s-1 after conducting experiments in optimized chemical and physicochemical conditions, contributing to the enhancement of productivity of 46% for biomass and 106% for chlorophyll. Urea was found to be the most effective nitrogen source with an increase of 70% and 160% biomass and chlorophyll productivity, respectively. Moreover, sucrose as a carbon source contributed to an increase of 97% and 264% biomass and chlorophyll productivity.

Anti-Diabetic Potential of Chlorella Pyrenoidosa-Based Mixture and its Regulation of Gut Microbiota.

The aim of the present study was to investigate the anti-diabetic effect of CGSGCG and its beneficial effects on gut microbiota in type 2 diabetes (T2D) mice induced by streptozotocin and high sucrose and high fat diet. The results showed that treatment with CGSGCG reduced fasting blood glucose, improved oral glucose tolerance test, protected the liver from injury, and reduced inflammation in T2D mice. The contents of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid and isovaleric acid in CGSGCG group were 2.49-, 1.74-, 3.31-, 1.93-, 1.36- and 1.30-fold than that of the model group. Moreover, administration of CGSGCG up-regulated the expression of INSR/IRS-1/PI3K/AKT/GLUT4 and mTOR but down-regulated the P38MAPK expression. Furthermore, the abundance of beneficial bacteria such as Verrucomicrobia, Proteobacteria, Osillibacter, Dubosiella and Lactococcus in intestinal tract increased, indicating that CGSCGG regulated and improved the bacterial community structure of T2D mice, which were closely related to glycometabolism.

Biosorption of Uranium from aqueous solution by green microalga Chlorella sorokiniana.

Uranium and its compounds are radioactive and toxic, as well as highly polluting and damaging the environment. Novel uranium adsorbents with high biosorption capacity that are both eco-friendly and cost-effective are continuously being researched. The non-living biomass of the fresh water green microalga Chlorella sorokiniana was used to study the biosorption of uranium from aqueous solution. The biosorption of uranium from aqueous solutions onto the biomass of microalga C. sorokiniana was investigated in batch studies. The results showed that the optimal pH for uranium biosorption onto C. sorokiniana was 2.5. Uranium biosorption occurred quickly, with an equilibrium time of 90 min. The kinetics followed a pseudo-second-order rate equation, and the biosorption process fit the Langmuir isotherm model well, with a maximum monolayer adsorption capacity of 188.7 mg/g. The linear plot of the DKR model revealed that the mean free energy E = 14.8 kJ/mol, confirming chemisorption adsorption with ion exchange mode. The morphology of the algal biomass was investigated using a scanning electron microscope and energy dispersive X-ray spectroscopy. The FTIR spectroscopy analysis demonstrated that functional groups (carboxyl, amino, and hydroxyl) on the algal surface could contribute to the uranium biosorption process, which involves ion exchange and uranium absorption, and coordination mechanisms. Thermodynamic simulations indicated that the uranium biosorption process was exothermic (ΔH = -19.5562 kJ/mol) and spontaneous at lower temperatures. The current study revealed that C. sorokiniana non-living biomass could be an efficient, rapid, low-cost, and convenient method of removing uranium from aqueous solution.

Magnetic Biohybrid Microrobot Multimers Based on Chlorella Cells for Enhanced Targeted Drug Delivery.

Magnetic micro-/nanorobots have been regarded as a promising platform for targeted drug delivery, and tremendous strategies have been developed in recent years. However, realizing precise and efficient drug delivery in vivo still remains challenging, in which the versatile integration of good biocompatibility and reconfiguration is the main obstacle for micro-/nanorobots. Herein, we proposed a novel strategy of magnetic biohybrid microrobot multimers (BMMs) based on Chlorella (Ch.) and demonstrated their great potential for targeted drug delivery. The spherical Ch. cells around 3-5 µm were magnetized with Fe3O4 to fabricate biohybrid microrobots and then loaded with doxorubicin (DOX). Using magnetic dipolar interactions, the microrobot units could reconfigure into chain-like BMMs as tiny dimers, trimers, and so forth via attraction-induced self-assembly and disassemble reversibly via repulsion. The BMMs exhibited diverse swimming modes including rolling and tumbling with high maneuverability, and the rolling dimer's velocity could reach 107.6 µm/s (∼18 body length/s) under a 70 Gs precessing magnetic field. Furthermore, the BMMs exhibited low cell toxicity, high DOX loading capacity, and pH-triggered drug release, which were verified by chemotherapy experiments toward HeLa cancer cells. Due to the remarkable versatility and facile fabrication, the BMMs demonstrate great potential for targeted anticancer therapy.

Hypoglycemic peptide-enriched hydrolysates of Corbicula fluminea and Chlorella sorokiniana possess synergistic hypoglycemic activity through inhibiting α-glucosidase and dipeptidyl peptidase-4 activity.

BACKGROUND: The prevalence of diabetes mellitus worldwide has increased in recent decades. Maintaining the level of blood glucose is the most basic and important issue for diabetics. This study aimed to investigate the hypoglycemic activity of a combination of hypoglycemic peptide-enriched hydrolysates of Corbicula fluminea (ACH) and Chlorella sorokiniana (PCH). RESULTS: Combined supplementation of ACH and PCH synergistically inhibited α-glucosidase and DPP4 activities in vitro. After 4 weeks of treatment with ACH and/or PCH, the plasma glucose concentration and insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), total cholesterol (TC) and triglyceride (TG) levels significantly decreased. The hypoglycemic peptides in ACH and PCH were purified and assayed for α-glucosidase and DPP4 activity. The hypoglycemic peptides in ACH and PCH effectively decreased α-glucosidase and DPP4 activities. In silico assays showed that these two peptide types have different docking poses, which determined their inhibitory effect against α-glucosidase and DPP4 activity. CONCLUSION: Combined treatment with hypoglycemic peptide-enriched ACH and PCH could modulate blood glucose by synergistically inhibiting α-glucosidase and DPP4 activities. © 2021 Society of Chemical Industry.

Butylated hydroxyl-toluene, 2,4-Di-tert-butylphenol, and phytol of Chlorella sp. protect the PC12 cell line against H2O2-induced neurotoxicity.

Oxidative stress is considered the main cause of cellular damage in a number of neurodegenerative disorders. One suitable ways to prevent cell damage is the use of the exogenous antioxidant capacity of natural products, such as microalgae. In the present study, four microalgae extracts, isolated from the Persian Gulf, were screened to analyze their potential antioxidant activity and free radical scavenging using ABTS, DPPH, and FRAP methods. The methanolic extracts (D1M) of green microalgae derived from Chlorella sp. exhibited potent free radical scavenging activity. In order to characterize microalgae species, microscopic observations and analysis of the expression of 18S rRNA were performed. The antioxidant and neuroprotective effects of D1M on H2O2-induced toxicity in PC12 cells were investigated. The results demonstrated that D1M significantly decreased the release of nitric oxide (NO), formation of intracellular reactive oxygen species (ROS), and the level of malondialdehyde (MDA), whereas it enhanced the content of glutathione (GSH), and activity of heme oxygenase 1 (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO1), and catalase (CAT) in PC12 cells exposed to H2O2. The pretreatment of D1M improved cell viability as measured by the MTT assay and invert microscopy, reduced cell apoptosis as examined by flow cytometry analysis, increased mitochondrial membrane potential (MMP), and diminished caspase-3 activity. The GC/MS analysis revealed that D1M ingredients have powerful antioxidant and anti-inflammatory compounds, such as butylated hydroxytoluene (BHT), 2,4-di-tert-butyl-phenol (2,4-DTBP), and phytol. These results suggested that Chlorella sp. extracts have strong potential to be applied as neuroprotective agents, for the treatment of neurodegenerative disorders.

Enhanced whole-cell biotransformation of 3-chloropropiophenone into 1-phenyl-1-propanone by hydrogel entrapped Chlorella emersonii (211.8b).

OBJECTIVES: This study focuses on dehalogenation of halogenated organic substrate (3-Chloropropiophenone) using both free and hydrogel entrapped microalgae Chlorella emersonii (211.8b) as biocatalyst. We aimed at successful immobilization of C. emersonii (211.8b) cells and to assess their biotransformation efficiency. RESULTS: Aquasorb (entrapping material in this study) was found to be highly biocompatible with the cellular growth and viability of C. emersonii. A promising number of entrapped cells was achieved in terms of colony-forming units (CFUs = 2.1 × 104) per hydrogel bead with a comparable growth pattern to that of free cells. It was determined that there is no activity of hydrogenase that could transform 1-phenyl-2-propenone into 1-phenyl-1-propanone because after 12 h the ratio between two products (0.36 ± 0.02) remained constant throughout. Furthermore, it was found that the entrapped cells have higher biotransformation of 3-chloropropiophenone to 1-phenyl-1-propanone as compared to free cells at every interval of time. 1-phenyl-2-propenone was excluded from the whole-cell biotransformation as it was also found in the control group (due to spontaneous generation). CONCLUSION: Hence, enhanced synthesis of 1-phenyl-1-propanone by entrapped Chlorella (211.8b) can be ascribed to either an enzymatic activity (dehalogenase) or thanks to the antioxidants from 211-8b, especially when they are in immobilized form. The aquasorb based immobilization of microalgae is highly recommended as an effective tool for exploiting microalgal potentials of biocatalysis specifically when free cells activities are seized due to stress.

Novel Spray Dried Algae-Rosemary Particles Attenuate Pollution-Induced Skin Damage.

The present study investigated the effect of spray-dried algae-rosemary particles against pollution-induced damage using ex-vivo human biopsies exposed to diesel engine exhaust (DEE). For this, the complexation of hydroalcoholic rosemary extract with Chlorella (RCH) and Spirulina (RSP) protein powders was conducted. The process efficiency and concentration of rosmarinic acid (RA), carnosic acid (CA), and carnosol (CR) phenolic compounds of both products were compared. The RSP spray-dried production was more efficient, and RSP particles presented higher CR and CA and similar RA concentrations. Therefore, spray-dried RSP particles were prioritized for the preparation of a gel formulation that was investigated for its ability to mitigate pollution-induced skin oxinflammatory responses. Taken altogether, our ex-vivo data clearly demonstrated the ability of RSP gel to prevent an oxinflammatory phenomenon in cutaneous tissue by decreasing the levels of 4-hydroxynonenal protein adducts (4HNE-PA) and active matrix metalloproteinase-9 (MMP-9) as well as by limiting the loss of filaggrin induced by DEE exposure. Our results suggest that the topical application of spirulina-rosemary gel is a good approach to prevent pollution-induced skin aging/damage.

Chemical Characterization, Antiproliferative and Antioxidant Activities of Polyunsaturated Fatty Acid-Rich Extracts from Chlorella sp. S14.

Microalgae is a rich source of polyunsaturated fatty acid. This study was conducted to identify and isolate microalgal strain with the potentials for producing polyunsaturated fatty acids (PUFAs) and determine its cytotoxic effect on some cancer cells. The algal strain (Chlorella sp. S14) was cultivated using modified BG-11 media, and algal biomass obtained was used for fatty acid extraction. Gas chromatographic-mass spectrometry was used to identify and quantify the levels of the fatty acid constituents. The total content of monounsaturated fatty acids (1.12%) was low compared to polyunsaturated fatty acids (PUFAs) (52.87%). Furthermore, n-3 PUFAs accounted for (12.37%) of total PUFAs with the presence of α-linolenic acid (2.16%) and cis-11,14,17-eicosatrienoic acid (2.16%). The PUFA-rich extract did not exhibit a cytotoxic effect on normal cells. Treatment with the PUFA-rich extract (150 µg/mL) significantly reduced cell viability in MCF-7 (31.58%) and A549 (62.56%) cells after the 48 h treatment. Furthermore, treatment of MCF-7 with fatty acid extracts (125 and 150 µg/mL) showed a significant reduction in MDA levels, increase in catalase activities and decrease in GSH level compared to untreated cells. However, a slight decrease in MDA level was observed in A549 cells after the 48 h treatment. There are no significant changes in catalase activities and GSH level in treated A549 cells. However, a slight reduction of NO levels was observed in treated MCF-7 and A549 cells. These results indicate the potentials of PUFA-rich extracts from Chlorella sp. S14 to reduce viability and modulate redox status in A549 and MCF-7 cells.

Investigation of Chlorella pyrenoidosa Protein as a Source of Novel Angiotensin I-Converting Enzyme (ACE) and Dipeptidyl Peptidase-IV (DPP-IV) Inhibitory Peptides.

Chlorella pyrenoidosa (C. pyrenoidosa) is a microalgae species with a remarkably high protein content that may potentially become a source of hypotensive and hypoglycemic peptides. In this study, C. pyrenoidosa proteins were extracted and hydrolyzed overnight with pepsin and trypsin with final degrees of hydrolysis of 18.7% and 35.5%, respectively. By LC-MS/MS, 47 valid peptides were identified in the peptic hydrolysate (CP) and 66 in the tryptic one (CT). At the concentration of 1.0 mg/mL, CP and CT hydrolysates inhibit in vitro the angiotensin-converting enzyme (ACE) activity by 84.2 ± 0.37% and 78.6 ± 1.7%, respectively, whereas, tested at cellular level at the concentration of 5.0 mg/mL, they reduce the ACE activity by 61.5 ± 7.7% and 69.9 ± 0.8%, respectively. At the concentration of 5.0 mg/mL, they decrease in vitro the DPP-IV activity by 63.7% and 69.6% and in Caco-2 cells by 38.4% and 42.5%, respectively. Short peptides (≤10 amino acids) were selected for investigating the potential interaction with ACE and DPP-IV by using molecular modeling approaches and four peptides were predicted to block both enzymes. Finally, the stability of these peptides was investigated against gastrointestinal digestion.

Evaluation of the Potential of Marine Algae Extracts as a Source of Functional Ingredients Using Zebrafish as Animal Model for Aquaculture.

Research on immunotherapeutic agents has become a focus for the treatment of fish diseases. The ability of algae to produce secondary metabolites of potential interest as immunotherapeutics has been documented. The present research intended to assess antiviral and antibacterial activities of macro- and microalgae extracts against viral and bacterial pathogens and explore their immunomodulatory potential using zebrafish (Danio rerio) larvae as a model organism. The cytotoxicity and antiviral activity of eight methanolic and ethanolic extracts from two macroalgae (Fucus vesiculosus, Ulva rigida) and two microalgae (Nannochloropsis gaditana, Chlorella sp.) were analyzed in established fish cell lines. Six extracts were selected to evaluate antibacterial activity by disk diffusion and growth inhibition assays. The three most promising extracts were characterized in terms of fatty acid composition, incorporated at 1% into a plant-based diet, and evaluated their effect on zebrafish immune response and intestinal morphology in a short-term feeding trial. All extracts exhibited in vitro antiviral activity against viral hemorrhagic septicemia and/or infectious pancreatic necrosis viruses. Methanolic extracts from F. vesiculosus and U. rigida were richer in saturated fatty acids and exhibited in vitro antibacterial action against several bacteria. Most promising results were obtained in vivo with F. vesiculosus methanol extract, which exerted an anti-inflammatory action when incorporated alone into diets and induced pro-inflammatory cytokine expression, when combined with the other extracts. Moreover, dietary inclusion of the extracts improved intestinal morphology. In summary, the results obtained in this study support the potential of algae as natural sources of bioactive compounds for the aquaculture industry.

Impact of phytochemicals and plant extracts on viability and proliferation of NK cell line NK-92 - a closer look at immunomodulatory properties of goji berries extract in human colon cancer cells.

INTRODUCTION: Due to the fact that lymphocytes NK (natural killer cells) are the first line of defence of the body against cancer, one of the goals of modern immunotherapy is the enhancement of their natural activities for the effective recognition, detection, and elimination of cancer cells. OBJECTIVE: The aim of the study was to evaluate the influence of selected phytochemicals (curcumin and resveratrol) and plant extracts (chlorella and goji berries) on NK cells viability and proliferation, as well as cytotoxic activity against colon cancer - one of the most common cancer worldwide. MATERIAL AND METHODS: The impact of phytochemicals, viability and proliferation of plant extracts on NK cells was examined in NK-92 cells using both LDH and MTT assays. The immunomodulatory properties of selected compounds were tested against human colon cancer cell line LS180 using the MTT test. RESULTS: Extracts of chlorella and goji berries significantly increased NK cell proliferation, while curcumin and resveratrol did not affect this process. Curcumin, as well as extracts of chlorella and goji berries, did not impact NK viability, while resveratrol significantly increased it. LDH test revealed the cytotoxic effect of chlorella extract and curcumin in NK-92 cell cultures. On the contrary, goji berries extract significantly decreased LDH level, while resveratrol did not affect the integrity of NK cell membranes. Studies conducted in co-cultures NK cells, also directly eliminated colon cancer cells. CONCLUSIONS: Performed studies revealed immunomodulatory properties of goji berries extract, which improved viability and proliferation of NK cells, and above all, significantly increased their ability to recognize and eliminate colon cancer cells.

Green synthesis of mono and bimetallic alloy nanoparticles of gold and silver using aqueous extract of Chlorella acidophile for potential applications in sensors.

Bimetallic or alloy nanoparticles (NPs) have improved properties compared to their monometallic forms. Microalgae being rich in biocompatible reductants and being ecofriendly are potential sources to synthesize fuctionalized NPs. In this study, biosynthesis of silver, gold, and bimetallic NPs was carried out via bioreduction using aqueous extract of algal isolate Chlorella acidophile, inhabitant of non-arable land. C. acidophile is known to contain highly bioactive functional moieties, which can serve as nanobiofactories for metallic NPs. Various characterization techniques viz, UV-visible spectrophotometer, X-ray diffraction analysis, X-ray photo-electron spectroscopy, and Raman spectroscopy were employed to determine their composition, structure, and crystal phase. The monometallic and bimetallic particles were found to be crystalline state and generally in a spherical shape. Their size ranged from 5 to 45 nm and the corresponding FTIR spectra indicated that the specific organic functional groups from algal extract were involved in the bio-reduction. Furthermore, the core-shell in the case of Au-Ag NPs was formed due to the simultaneous reduction of gold and silver ions. An enhanced and more pronounced Raman spectra of Au-Ag NP compared to individual Au NP indicated the improved properties of bimetallic NPs, the latter having been of immense potential to be used as sensors in industries.

A simple and fast experimental protocol for the extraction of xanthophylls from microalga Chlorella luteoviridis.

This study aimed to optimize the key parameters of extraction methods and to increase the recovery yields of intact xanthophylls (violaxanthin, zeaxanthin, astaxanthin) from microalgae (Chlorella luteoviridis). An effective, simple, and fast extraction protocol is described. It consists of a grinding pretreatment followed by a microwave-assisted extraction, using ethanol 90% as an environmentally preferable extraction solvent. Xanthopylls were quantified using high performance liquid chromatography. Irradiation time of 6 s only resulted in the extraction of violaxanthin (4.479 ± 0.009 mg/g), astaxanthin (4.154 ± 0.013 mg/g), and zeaxanthin (4.776 ± 0.120 mg/g). The described protocol seems to be the fastest extraction method of xantophylls compared to the literature and could be an advantage for industrial scale, while saving time and energy.

Transcriptome analysis reveals possible antitumor mechanism of Chlorella exopolysaccharide.

Microalgae, one of the most important classes of biomass producers, can produce exopolysaccharides similar to bacteria. The exopolysaccharide from Chlorella (CEPS) displays remarkable anticancer activity the mechanism of which remains to be elucidated. In this study, we analyzed the inhibitory effect of CEPS on the growth of HeLa cells. The results showed that CEPS inhibited the proliferation, decreased the viability, and changed the morphology of HeLa cells. Transcriptome analysis showed that 1894 genes were differentially expressed in the CEPS-treated group compared with the control group, including 1076 genes that were upregulated and 818 genes that were downregulated. The results of gene function enrichment analysis showed that the differentially expressed genes (DEGs) were significantly enriched in apoptosis and tumor-related biological processes and participated in several cancer and apoptosisrelated signaling pathways, including the MAPK signaling pathway, TNF signaling pathway, and the PI3K-Akt signaling pathway. The protein-protein interaction network identified 13 DEGs including PTPN11, RSAD2, ISG15, IFIT1, MX2, IFIT2, OASL, OAS1, JUN, OAS2, XAF1, ISG20, and IRF9 as hub genes. Our results suggest that CEPS is a promising therapeutic drug for the follow-up interventional therapy of cancer.

Cellular and physiological approaches to evaluate the chelating effect of Chlorella on metal ion stressed lymphocytes.

Chlorella is a green alga consumed as dietary food supplement in pulverized form. In addition to its high nutritional value, it is reported as an excellent detoxifying agent. The pulverized Chlorella is partially soluble in water and insoluble portion has been reported for removal of mercury, cadmium and radioactive strontium from body. Chlorella contains a variety of metal-binding functional groups such as carboxyl, amino, phosphoryl, hydroxyl and carbonyl groups, which has high affinity towards various metal ions. The present study was envisaged to evaluate the chelating effect of water soluble fraction of Chlorella powder (AqCH) on metal ions. Fura-2 fluorescence ratio (F340/F380) was measured by fluorescence spectrometer (FS) after the exposure of chloride salt of metals viz., strontium, cobalt, barium, cesium, thallium and mercury to lymphocytes. Pretreatment of AqCH (0.1-20 mg mL-1) was given to evaluate the attenuating effect on fura-2 fluorescence ratio induced by metal ions. The intracellular levels of these metal ions were analyzed by atomic absorption spectrophotometer (AAS) and fluorescence microscopy (FM). Pretreatment with AqCH significantly attenuated the metal induced fluorescence ratio in dose-dependent manner. The results of AAS and FM were found in coherence with fura-2 fluorescence ratio which emphasized that AqCH significantly prevented the metal ions internalization. The present study suggests AqCH chelates with these metal ions and prevents its interaction with cells thereby reducing the intracellular mobilization of Ca2+.

Molecular and Structural Characterizations of Lipases from Chlorella by Functional Genomics.

Microalgae have been poorly investigated for new-lipolytic enzymes of biotechnological interest. In silico study combining analysis of sequences homologies and bioinformatic tools allowed the identification and preliminary characterization of 14 putative lipases expressed by Chlorella vulagaris. These proteins have different molecular weights, subcellular localizations, low instability index range and at least 40% of sequence identity with other microalgal lipases. Sequence comparison indicated that the catalytic triad corresponded to residues Ser, Asp and His, with the nucleophilic residue Ser positioned within the consensus GXSXG pentapeptide. 3D models were generated using different approaches and templates and demonstrated that these putative enzymes share a similar core with common α/ß hydrolases fold belonging to family 3 lipases and class GX. Six lipases were predicted to have a transmembrane domain and a lysosomal acid lipase was identified. A similar mammalian enzyme plays an important role in breaking down cholesteryl esters and triglycerides and its deficiency causes serious digestive problems in human. More structural insight would provide important information on the enzyme characteristics.