Dietary Chlorella vulgaris Ameliorates Altered Immunomodulatory Functions in Cyclophosphamide-Induced Immunosuppressive Mice

XQZ3, a Chlorella pyrenoidosa polysaccharide suppresses cancer progression by restraining mitochondrial bioenergetics via HSP90/AKT signaling pathway

The mitochondria are known to exert significant influence on various aspects of cancer cell physiology. The suppression of mitochondrial function represents a novel avenue for the advancement of anti-cancer pharmaceuticals. The heat shock protein HSP90 functions as a versatile regulator of mitochondrial metabolism in cancer cells, rendering as a promising target for anticancer interventions. In this work, a novel acid polysaccharide named as XQZ3 was extracted from Chlorella pyrenoidosa and purified by DEAE-cellulose and gel-filtration chromatography. The structural characteristic of XQZ3 was evaluated by monosaccharides composition, methylation analysis, TEM, FT-IR, and 2D-NMR. It was found that XQZ3 with a molecular weight of 29.13 kDa was a complex branched polysaccharide with a backbone mainly composed of galactose and mannose. It exhibited good antitumor activity in vitro and in vivo by patient-derived 3D organoid models and patient-derived xenografts models. The mechanistic investigations revealed that XQZ3 specifically interacted with HSP90, impeding the activation of the HSP90/AKT/mTOR signaling cascade. This, in turn, led to the induction of mitochondrial dysfunction, autophagy, and apoptosis, ultimately resulting in the demise of cancer cells due to nutrient deprivation. This study offers a comprehensive theoretical foundation for the advancement of XQZ3, a novel polysaccharide inhibitor targeting HSP90, with potential as an effective therapeutic agent against cancer.

Physicochemical characterization, digestion profile and gut microbiota regulation activity of intracellular polysaccharides from Chlorella zofingiensis

A number of studies have shown that the polysaccharides from microalgae exhibit diverse biological activities, however, little is known about their digestibility and impact on human gut microbiota. In this study, a simulating digestion and fermentation system were established to investigate the digestibility and fermentation of intracellular polysaccharides from Chlorella zofingiensis (CZIP-S3). The results indicated that CZIP-S3 is a macromolecular polysaccharide composed of mannose, glucose, galactose and rhamnose, consisting of a main chain and two branched repeating units. CZIP-S3 could not be digested in the upper gastrointestinal tract. However, CZIP-S3 could be metabolized into smaller molecules by the gut microbiota. The pH values continuously decrease during fermentation, whereas, the amount of short-chain fatty acids steadily increase. Furthermore, CZIP-S3 could modulate the composition of gut microbiota, via lowering the ratio of Firmicutes/Bacteroidetes and increasing the relative abundance of Bacteroides, Bifidobacterium and Akkermansia. The data suggested that CZIP-S3 could potentially be used as an ingredient for functional foods or prebiotics to improve human health by promoting the relative abundances of beneficial bacteria.

Benefits of Chlorella vulgaris against Cadmium Chloride-Induced Hepatic and Renal Toxicities via Restoring the Cellular Redox Homeostasis and Modulating Nrf2 and NF-KB Pathways in Male Rats

In our life scenarios, we are involuntarily exposed to many heavy metals that are well-distributed in water, food, and air and have adverse health effects on animals and humans. Cadmium (Cd) is one of the most toxic 10 chemicals reported by The World Health Organization (WHO), affecting organ structure and function. In our present study, we use one of the green microalga Chlorella vulgaris (ChV, 500 mg/kg body weight) to investigate the beneficial effects against CdCl2-induced hepato-renal toxicity (Cd, 2 mg/kg body weight for 10 days) on adult male Sprague-Dawley rats. In brief, 40 adult male rats were divided into four groups (n = 10); Control, ChV, Cd, and Cd + ChV. Cadmium alters liver and kidney architecture and disturbs the cellular signaling cascade, resulting in loss of body weight, alteration of the hematological picture, and increased ALT, AST, ALP, and urea in the blood serum. Moreover, cadmium puts hepatic and renal cells under oxidative stress due to the up-regulation of lipid peroxidation resulting in a significant increase in the IgG level as an innate immunity protection and induction of the pro-inflammatory cytokines (IL-1β and TNF-α) that causes hepatic hemorrhage, irregular hepatocytes in the liver and focal glomeruli swelling and proximal tubular degeneration in the kidney. ChV additive to CdCl2, could organize the protein translation process via NF-kB/Nrf2 pathways to prevent oxidative damage by maintaining cellular redox homeostasis and improving the survival of and tolerance of cells against oxidative damage caused by cadmium. The present study shed light on the anti-inflammatory and antioxidative properties of Chlorella vulgaris that suppress the toxicity influence of CdCl2.

Prevention effect of total ginsenosides and ginseng extract from Panax ginseng on cyclophosphamide-induced immunosuppression in mice

Oral decoction is widely applied in traditional Chinese medicines. The polysaccharides of decoction promote the exposure of small molecules and increase their bioavailability. This study mainly compared the component and activities of total ginsenosides (TGS) and ginseng extract (GE) on immunosuppressed mice induced by cyclophosphamide. Thirty-two mice were randomly divided into control, model, TGS, and GE groups. The mice were orally administered for 28 days and then injected with cyclophosphamide on the last four days. The results of component analysis showed the total content of 12 ginsenosides in TGS (67.21%) was higher than GE (2.04%); the total content of 17 amino acids in TGS (1.41%) was lower than GE (5.36%); the total content of 10 monosaccharides was similar in TGS (74.12%) and GE (76.36%). The animal results showed that both TGS and GE protected the hematopoietic function of bone marrow by inhibiting cell apoptosis, and recovering the normal cell cycle of BM; maintained the dynamic balance between the Th1 and Th2 cells; also protected the spleen, thymus, and liver. Meanwhile, TGS and GE protected the intestinal bacteria of immunosuppressed mice by increasing the abundance of lactobacillus and decreasing the abundance of the odoribacter and clostridia_UCG-014. The prevention effect of GE was superior to TGS in some parameters. In conclusion, TGS and GE protected the immune function of immunosuppressed mice induced by cyclophosphamide. Meanwhile, GE showed higher bioavailability and bioactivity compared with TGS, because the synergistic effect of polysaccharides and ginsenosides plays an important role in protecting the immune function.

Prevention effect of total ginsenosides and ginseng extract from Panax ginseng on cyclophosphamide‐induced immunosuppression in mice

Oral decoction is widely applied in traditional Chinese medicines. The polysaccharides of decoction promote the exposure of small molecules and increase their bioavailability. This study mainly compared the component and activities of total ginsenosides (TGS) and ginseng extract (GE) on immunosuppressed mice induced by cyclophosphamide. Thirty‐two mice were randomly divided into control, model, TGS, and GE groups. The mice were orally administered for 28 days and then injected with cyclophosphamide on the last four days. The results of component analysis showed the total content of 12 ginsenosides in TGS (67.21%) was higher than GE (2.04%); the total content of 17 amino acids in TGS (1.41%) was lower than GE (5.36%); the total content of 10 monosaccharides was similar in TGS (74.12%) and GE (76.36%). The animal results showed that both TGS and GE protected the hematopoietic function of bone marrow by inhibiting cell apoptosis, and recovering the normal cell cycle of BM; maintained the dynamic balance between the Th1 and Th2 cells; also protected the spleen, thymus, and liver. Meanwhile, TGS and GE protected the intestinal bacteria of immunosuppressed mice by increasing the abundance of lactobacillus and decreasing the abundance of the odoribacter and clostridia_UCG‐014. The prevention effect of GE was superior to TGS in some parameters. In conclusion, TGS and GE protected the immune function of immunosuppressed mice induced by cyclophosphamide. Meanwhile, GE showed higher bioavailability and bioactivity compared with TGS, because the synergistic effect of polysaccharides and ginsenosides plays an important role in protecting the immune function.

Chlorella vulgaris Modulates Gut Microbiota and Induces Regulatory T Cells to Alleviate Colitis in Mice

Chlorella vulgaris (C. vulgaris) is unicellular green algae consumed worldwide as a functional food. The immune stimulatory function of C. vulgaris is known; however, no study has elucidated its immune regulatory potential and associated microbiome modulation. In the current study, we aimed to validate the immune regulatory role of C. vulgaris mediated through two mechanisms. Initially, we assessed its ability to promote the expansion of the regulatory T cell (Treg) population. Subsequently, we investigated its impact on gut microbiota composition and associated metabolites. The supplementation of C. vulgaris altered the gut microbiota composition, accompanied by increased short-chain fatty acid (SCFAs) production in mice at homeostasis. We later used C. vulgaris in the treatment of a DSS-induced colitis model. C. vulgaris intervention alleviated the pathological symptom of colitis in mice, with a corresponding increase in Treg levels. As C. vulgaris is a safe and widely used food supplement, it can be a feasible strategy to instigate cross-talk between the host immune system and the intestinal flora for the effective management of inflammatory bowel disease (IBD).

The Structural Characterization and Immunomodulatory Activity of Polysaccharides from Pleurotus abieticola Fruiting Bodies

Polysaccharides obtained from mushrooms have been reported to possess immunomodulatory properties. In this study, a water-soluble polysaccharide was purified from the fruiting bodies of Pleurotus abieticola, entitled PAPS1. After its composition and structural analysis, the immunomodulatory activity was investigated in immunosuppressed mice induced by cyclophosphamide (CTX) at a dosage of 70 mg/kg by intraperitoneal injection for 7 days. After 28 days of intragastric administration, PAPS1 alleviated cyclophosphamide (CTX)-induced histopathological damage and increased the expressions of splenic CD4, CD8, CD56 and IgM in the serums of immunosuppressed mice. PAPS1 suppressed the oxidative stress indicated by preventing the increases in ROS and MDA levels. According to the intestinal microflora analysis, PAPS1 regulated 11 bacteria at the gene level, including Helicobacter and Paraprevotella, which are related to immunity and oxidative capacity. Compared with CTX-treated mice, significant increases in immune-related cytokines, such as interleukin (IL)-2, IL-6 and IL-12 in the serums of mice treated with PAPS1, were observed. Finally, PAPS1 can strongly increase the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream proteins. In conclusion, PAPS1-boosted immunity may be related to its suppression on oxidative stress via enhancing the activity of Nrf2 signaling. Thus, PAPS1 can be investigated as a candidate for immunomodulatory therapy.

Research Progresses on the Physiological and Pharmacological Benefits of Microalgae-Derived Biomolecules

Microalgae are a kind of photoautotrophic microorganism, which are small, fast in their growth rate, and widely distributed in seawater and freshwater. They have strong adaptability to diverse environmental conditions and contain various nutrients. Many scholars have suggested that microalgae can be considered as a new food source, which should be developed extensively. More importantly, in addition to containing nutrients, microalgae are able to produce a great number of active compounds such as long-chain unsaturated fatty acids, pigments, alkaloids, astaxanthin, fucoidan, etc. Many of these compounds have been proven to possess very important physiological functions such as anti-oxidation, anti-inflammation, anti-tumor functions, regulation of the metabolism, etc. This article aimed to review the physiological functions and benefits of the main microalgae-derived bioactive molecules with their physiological effects.

Immunomodulatory functional foods and their molecular mechanisms

The immune system comprises a complex group of processes that provide defense against diverse pathogens. These defenses can be divided into innate and adaptive immunity, in which specific immune components converge to limit infections. In addition to genetic factors, aging, lifestyle, and environmental factors can influence immune function, potentially affecting the susceptibility of the host to disease-causing agents. Chemical compounds in certain foods have been shown to regulate signal transduction and cell phenotypes, ultimately impacting pathophysiology. Research has shown that the consumption of specific functional foods can stimulate the activity of immune cells, providing protection against cancer, viruses, and bacteria. Here, we review a number of functional foods reported to strengthen immunity, including ginseng, mushrooms, chlorella, and probiotics (Lactobacillus plantarum). We also discuss the molecular mechanisms involved in regulating the activity of various types of immune cells. Identifying immune-enhancing functional foods and understanding their mechanisms of action will support new approaches to maintain proper health and combat immunological diseases.

Evidence is building to support the idea that specific ‘functional foods’ can stimulate the activity of cells and signaling systems of the immune system to provide protection against cancer, viruses and bacteria. Sanguine Byun and colleagues at Yonsei University in Seoul, South Korea, review research into a range of functional foods, foods thought to have health benefits beyond their nutritional value. These include ginseng, mushrooms, the green algae called Chlorella and the probiotic bacteria Lactobacillus plantarum. They also consider individual components of foods such as poly-gamma-glutamate, a natural polymer made by bacteria. A wide body of research is revealing diverse molecular mechanisms through which biochemicals in functional foods can modulate different aspects of the immune system. These include effects on both non-specific innate immunity and adaptive immunity, which targets specific invading pathogens and diseased cells.

Immune-Enhancing Effects of Lactobacillus plantarum 200655 Isolated from Korean Kimchi in a Cyclophosphamide-Induced Immunocompromised Mouse Model

In this study, we evaluated the immune-enhancing activity of kimchi-derived Lactobacillus plantarum 200655 on immune suppression by cyclophosphamide (CP) in ICR mice. Animals were fed distilled water or 1×10⁹ colony-forming unit/kg B.W. 200655 or Lactobacillus rhamnosus GG as a positive control for 14 days. An in vivo model of immunosuppression was induced using CP 150 and 100 mg/kg B.W. at 7 and 10 days, respectively. Body weight, spleen index, spleen weight, and gene expression were measured to estimate the immune-enhancing effects. The dead 200655 (D-200655) group showed an increased spleen weight compared to the sham control (SC) group. Similarly, the spleen index was significantly higher than that in the CP-treated group. The live 200655 (L-200655) group showed an increased mRNA expression of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 in splenocytes. Also, the iNOS and COX-2 mRNA expression was upregulated in the L-200655 group compared to the CP-only (SC) group. The phosphorylation of ERK and MAPK was also upmodulated in the L-200655 group. These results indicate that L. plantarum 200655 ameliorated CP-induced immune suppression, suggesting that L. plantarum 200655 may have the potential to enhance the immune system.

The immunomodulatory effects of Carapax Trionycis ultrafine powder on cyclophosphamide-induced immunosuppression in Balb/c mice

BACKGROUND

There are abundant resources of Carapax Trionycis from soft-shelled turtle processing wastes each year in China. Our preliminary work showed that Carapax Trionycis ultrafine powder (CTUP) obtained using ball-milling with a particle size of 2.24 μm (D0.025) contained more active ingredients. The CTUP D0.025 has a good bioaccessibility, but there has been no report about the immunomodulatory function of CTUP. Therefore, using a cyclophosphamide-induced immunosuppression mice model, we investigated the immunomodulatory effects of CTUP D0.025.

RESULTS

The results indicated that CTUP D0.025 administration significantly improved the immune organ (bone marrow, thymus and spleen) indices, ameliorated spleen tissue morphology and increased the capacity of splenocyte proliferation and the activity of macrophage phagocytosis. CTUP D0.025 also significantly promoted the secretion of cytokines (IL-2, IL-4, IL-10, IFN-γ and TNF-α), improved the related mRNA expression levels of IL2, IFN-γ, T-bet and GATA3 in immunosuppressed mice and increased the production of serum hemolysin and the levels of IgG, IgM as well as complement C₃ . Moreover, CTUP D0.025 administration enhanced the antioxidant capacity of mice, exhibited a moderating effect on the damage of bone and skeletal muscle and improved the recovery of bone mineral density and calcium metabolism.

CONCLUSIONS

These findings demonstrated that CTUP D0.025 had an effective immune-enhancing function in immunosuppressive Balb/c mice and also exhibited anti-osteoporosis properties. © 2020 Society of Chemical Industry.

Protective role of Chlorella vulgaris with Thiamine against Paracetamol induced toxic effects on haematological, biochemical, oxidative stress parameters and histopathological changes in Wistar rats

Paracetamol is extensively consumed as an analgesic and antipyretic drug, but at a high dose level, it leads to deleterious side effects, such as hepatic and nephrotoxicity. This research aimed to estimate the prophylactic efficacy of Chlorella vulgaris and/or thiamine against paracetamol (P) induced hepatorenal and cardiac toxicity. Forty-eight female Wistar rats were randomly divided into eight equal groups (n = 6 rats). Group 1, normal control group. Group 2, Paracetamol group. Groups 3, 4 and 5 were treated with Silymarin drug, Chlorella vulgaris alga, Chlorella vulgaris alga supplemented with thiamine, respectively daily for 7 successive days, then all were administered Paracetamol (2gm/kg. bwt.). While, Groups 6, 7 and 8 were treated by Silymarin, Chlorella vulgaris alga, Chlorella vulgaris supplemented with thiamine, respectively daily for 7 successive days without paracetamol administration. Our results clarified that Paracetamol toxicity caused significant adverse effects on hematological, serum biochemical parameters, and oxidant -antioxidant status as well as histopathological picture of heart, liver, and kidney. However, in the Paracetamol intoxicated groups pretreatment either with Chlorella vulgaris alone or plus thiamine successfully improved the undesirable deleterious effects of paracetamol, and restored almost all variables to near their control levels. This study has finished to that oxidative stress participates in the pathogenesis of paracetamol-induced toxicity in rats and using Chlorella vulgaris alga either alone or plus thiamine alongside their health benefits can protect against oxidative harmful effects induced by paracetamol through their free radical scavenging and powerful antioxidant effects, and they can be used as propylactic agents against paracetamol-induced toxicity.

The immune-enhancing effect of anthocyanin-fucoidan nanocomplex in RAW264.7 macrophages and cyclophosphamide-induced immunosuppressed mice

Aronia, a healthy fruit well known as black chokeberry, has health-promoting effects on hypertension, oxidative stress, and diabetes. Despite many reports of bioactivities of aronia, there is little scientific research on the potential for immune-enhancement. So, anthocyanin-fucoidan nanocomplex (AFNC, a nanocomplex of aronia extract and fucoidan) has been developed to improve immune-enhancement. This study aimed to identify immunomodulatory effects and underlying mechanisms of AFNC using RAW264.7 macrophages and cyclophosphamide-induced immunosuppressed mice. As a result, AFNC-treated RAW264.7 macrophages elevated the production of IL-2, IL-6, tumor necrosis factor (TNF)-α, and nitric oxide (NO). AFNC-enhanced inducible NO synthase expression via nuclear factor-κB signaling pathways. AFNC dose-dependently increased levels of IL-2, IL-6, TNF-α, IL-10, IL-12, interferon-γ, or IL-4 in the serum and spleen of immunosuppressed mice. Taken together, AFNC encourages the immune-enhancing activity through immunostimulatory cytokine production by activation of macrophage. Therefore, these results suggest that AFNC is useful for immunodeficiency-related disorders. PRACTICAL APPLICATIONS: In these days of prevalence of infectious diseases, individual immunity is very important. AFNC has the immune-enhancing effects through immunostimulatory cytokine production by activation of macrophage. Therefore, AFNC could be widely applied to ameliorate a variety of diseases caused by immunosuppression such as infectious diseases.

Chlorella sp. and Nannochloropsis sp. Inclusion in Plant-Based Diets Modulate the Intestine and Liver Antioxidant Mechanisms of European Sea Bass Juveniles

This study aimed to evaluate the effects of including microalgae Chlorella sp. or Nannochloropsis sp. in plant-based diets on antioxidant mechanisms of European sea bass (Dicentrarchus labrax) juveniles. For this purpose, three isoproteic (50%) and isolipidic (19%) diets were formulated: a practical diet, containing 15% fish meal (FM) and plant ingredients as the protein source and a mixture of fish oil and vegetable oils (40: 60) as lipid source (control diet); and two diets identical to the control but with the FM replaced by Nannochloropsis sp. or Chlorella sp. (diets Nanno and Chlo, respectively). The diets were offered to quadruplicate groups of 25 fish (initial body weight: 24 ± 1 g) for 11 weeks and then enzymatic and non-enzymatic antioxidant mechanisms and lipid oxidative biomarkers were assessed in the liver and intestine of these fish. Results showed that the antioxidant response was tissue-dependent, with the liver exhibiting lower glutathione peroxidase and glucose-6-phosphate dehydrogenase (only in Chlo group) activities, and intestine lower superoxide dismutase activity with the diets including microalgae compared to control diet. An increase of oxidized glutathione content was also observed in the intestine of fish fed the microalgae diets. Catalase and glutathione reductase activities, oxidative stress index, and total and reduced glutathione, were unaffected by dietary treatments in both tissues. Overall, the lipid peroxidation status was not compromised by the replacement of FM by microalgae.

Antioxidative and immunoprotective potential of Chlorella vulgaris dietary supplementation against chlorpyrifos-induced toxicity in Nile tilapia

This study highlighted the effects of chronic chlorpyrifos (CPF) exposure on Nile tilapia (Oreochromis niloticus) and the benefits of using dietary Chlorella vulgaris (Ch) to ameliorate CPF-induced toxicity. Genes encoding antioxidant enzymes and stress-responsive proteins in the liver as well as cytokine expression in the spleen and head kidney were evaluated in O. niloticus fed with a basal diet or diets containing 1, 2, and 3% of supplementary Ch against 15 mg/L CPF at 4 and 8 weeks. CPF-exposed groups displayed a notable induction in the hepatic expression of heat shock protein 70/hsp70, glutathione peroxidase/GPx, and glutathione synthase/GSS, while glutathione reductase/GSR was markedly decreased. The mRNA levels of interleukin 1β/IL-1β, TNF-α, transforming growth factor β1/TGFβ1, and interleukin 8/ IL-8 in the spleen and head kidney increased significantly after CPF exposure. Interestingly, Ch supplementation, particularly at levels 2 and 3%, was able to modulate the stress and immune-related genes of Nile tilapia sub-chronically exposed to CPF. These outcomes provide valuable insights regarding the toxic impact of chronic exposure to CPF in fish at the molecular level and a better understanding of the Ch dietary vital roles. Besides, our findings encourage adequate monitoring of pesticide levels owing to its impacts on fish health and human as a final consumer.

Protective effects of polysaccharides from Cordyceps gunnii mycelia against cyclophosphamide-induced immunosuppression to TLR4/TRAF6/NF-κB signalling in BALB/c mice

Polysaccharides are closely associated with immune regulation. In this study, the aim was to investigate the effect of polysaccharides from Cordyceps gunnii mycelia (PPS) in cyclophosphamide (CTX)-induced immunodeficient mice. Compared with the CTX-induced immunosuppressed mice, the spleen and thymus indexes in mice with orally administered PPS were significantly increased, body weight loss was alleviated, and the natural killer (NK) cytotoxicity and proliferative activities of the lymphocytes were elevated. The recovery of peripheral white blood cells, red blood cells, hemoglobins and platelets was accelerated. Furthermore, the results from ELISA showed that PPS could up-regulate the serum levels of IL-2, IL-12, IFN-γ and IgG, and reduce the level of TGF-β. Histopathological analysis of the spleen revealed the protective effect of PPS against CTX-induced immunosuppression. Western blotting results showed that PPS possessed immunomodulatory activity via TLR4/TRAF6/NF-κB signalling pathways. Finally, the intestinal absorption of PPS was poor, as detected in the Caco-2 transwell system. Taken together, these findings suggest that PPS plays a crucial role in protection against immunosuppression in cyclophosphamide-treated mice and could be a potential candidate for use in immune therapy regimens.

Immune Relevant and Immune Deficient Mice: Options and Opportunities in Translational Research

In 1989 ILAR published a list and description of immunodeficient rodents used in research. Since then, advances in understanding of molecular mechanisms; recognition of genetic, epigenetic microbial, and other influences on immunity; and capabilities in manipulating genomes and microbiomes have increased options and opportunities for selecting mice and designing studies to answer important mechanistic and therapeutic questions. Despite numerous scientific breakthroughs that have benefitted from research in mice, there is debate about the relevance and predictive or translational value of research in mice. Reproducibility of results obtained from mice and other research models also is a well-publicized concern. This review summarizes resources to inform the selection and use of immune relevant mouse strains and stocks, aiming to improve the utility, validity, and reproducibility of research in mice. Immune sufficient genetic variations, immune relevant spontaneous mutations, immunodeficient and autoimmune phenotypes, and selected induced conditions are emphasized.

Chlorella vulgaris modulates the expression of senescence-associated genes in replicative senescence of human diploid fibroblasts

Human diploid fibroblasts (HDFs) cultured in vitro have limited capacity to proliferate after population doubling is repeated several times, and they enter into a state known as replicative senescence or cellular senescence. This study aimed to investigate the effect of Chlorella vulgaris on the replicative senescence of HDFs by determining the expression of senescence-associated genes. Young and senescent HDFs were divided into untreated control and C. vulgaris-treated groups. A senescence-associated gene transcription analysis was carried out with qRT-PCR. Treatment of young HDFs with C. vulgaris reduced the expression of SOD1, CAT and CCS (p < 0.05). In addition, the expression of the SOD2 gene was increased with C. vulgaris treatment in young, pre-senescent and senescent HDFs (p < 0.05). Treatment of senescent HDFs with C. vulgaris resulted in the downregulation of TP53 gene expression. The expression of the CDKN2A gene was significantly decreased upon C. vulgaris treatment in young and senescent HDFs. C. vulgaris treatment was also found to significantly upregulate the expression of the MAPK14 gene in pre-senescent HDFs. In addition, the expression of MAPK14 was significantly upregulated compared to that in the untreated senescent HDFs (p < 0.05). In summary, the expression of senescence-associated genes related to antioxidants and the insulin/insulin-like growth factor-1 signalling, DNA damage-associated signalling, cell differentiation and cell proliferation pathways was modulated by C. vulgaris during replicative senescence of human diploid fibroblasts.

Effect of inhibiting ACAT-1 expression on the growth and metastasis of Lewis lung carcinoma

Accumulating evidence suggests that acetyl-CoA acetryltransferase 1 (ACAT-1) may mediate tumor development and metastasis. However, the specific function served by ACAT-1 in lung cancer is not well understood. Therefore, the present study initially verified that ACAT-1 was overexpressed in Lewis lung carcinoma (LLC) tissues compared with non-LLC mice and that this overexpression promoted the proliferation, invasion and metastasis of these LLC samples. Western blotting, immunofluorescence microscopy and flow cytometry allowed the present study to determine that the ACAT-1 inhibitor avasimibe significantly reduced the expression of ACAT-1 in LLC compared with LLC cells that are not treated with avasimibe (P<0.05). A combination of Cell Counting Kit-8 and wound healing assays demonstrated that downregulating ACAT-1 expression sufficiently inhibited the proliferation of LLC cells. Avasimibe promoted LLC cell apoptosis as assessed by a Annexin V/propidium iodide double staining assay. Furthermore, avasimibe inhibited tumor growth in vivo and improved immune responses, with tissue biopsies from LLC model mice exhibiting higher levels of ACAT-1 compared with in healthy controls. Altogether, the results of the present study reveal that avasimibe may inhibit the progression of LLC by downregulating the expression of ACAT-1, which may thus be a potential novel therapeutic target for lung cancer treatment.

Transcriptional response of cultured porcine intestinal epithelial cells to micro algae extracts in the presence and absence of enterotoxigenic Escherichia coli

Background

Micro algae's are worldwide considered as an alternative source of proteins in diets for animals and humans. Micro algae also produce an array of biological active substances with potential to induce beneficial and health promoting effects. To better understand the mode of action of micro algae's when applied as additive in diets, porcine intestinal epithelial cells (IPEC-J2), stressed by enterotoxigenic Escherichia coli (ETEC) or under non-stressed conditions, were exposed to micro algae extracts and changes in gene expression were recorded.

Methods

IPEC-J2 cells were exposed for 2 and 6 h to extracts prepared from the biomass of the microalgae Chlorella vulgaris (C), Haematococcus pluvialis (H), Spirulina platensis (S), or a mixture of Scenedesmus obliques and Chlorella sorokiniana (AM), in the absence and presence of ETEC. Gene expression in cells was measured using porcine "whole genome" microarrays.

Results

The micro algae extracts alone enhanced the expression of a set of genes coding for proteins with biological activity that are secreted from cells. These secreted proteins (hereafter denoted as effector proteins; EPs) may regulate processes like remodelling of the extracellular matrix, activation of an antiviral/bacterial response and oxygen homeostasis in the intestine and periphery. Elevated gene expression of immunostimulatory proteins CCL17, CXCL2, CXCL8 (alias IL8), IFNA, IFNL1, HMOX1, ITGB3, and THBS1 was observed in response to all four extracts in the absence or presence of ETEC. For several of these immunostimulatory proteins no elevated expression was observed when cells were exposed to ETEC alone. Furthermore, all extracts highly stimulated expression of an antisense RNA of the mitochondrial/peroxisome symporter SLC25A21 gene in ETEC-challenged cells. Inhibition of SLC25A21 translation by this antisense RNA may impose a concentration gradient of 2-oxoadipic and 2-oxoglutarate, both metabolites of fatty acid β-oxidation, between the cytoplasm and the interior of these organelles.

Conclusions

Exposure of by ETEC stressed intestinal epithelium cells to micro algae extracts affected "fatty acid β-oxidation", ATP and reactive oxygen species production and (de) hydroxylation of lysine residues in procollagen chains in these cells. Elevated gene expression of specific EPs and immunostimulatory proteins indicated that micro algae extracts, when used as feed/food additive, can steer an array of metabolic and immunological processes in the intestines of humans and monogastric animals stressed by an enteric bacterial pathogen.

Influences of Chlorella vulgaris dietary supplementation on growth performance, hematology, immune response and disease resistance in Oreochromis niloticus exposed to sub-lethal concentrations of penoxsulam herbicide

Little is known regarding the impact of penoxsulam, a fluorinated benzenesulfonamid rice herbicide, on Oreochromis niloticus (O. niloticus). Therefore, the current study was undertaken to highlight the effects of penoxsulam exposure on O. niloticus and to evaluate the advantages of Chlorella vulgaris (CV) dietary supplementation against the induced effects. The 96-h lethal concentration 50 (LC₅₀) penoxsulam value for O. niloticus was estimated at 8.948 mg/L by probit analysis in a static bioassay experiment. Next, 360 healthy fish were randomly allocated into 6 treatment groups. The T1 group served as the negative control and was fed a basal diet. The T2 group served as the positive control and was fed a basal diet supplemented with 10% CV. The fish in the T3 and T4 groups were exposed to 1/10 the 96-h LC₅₀ of penoxsulam (0.8948 mg/L) and were fed the basal diet alone or the basal diet supplemented with 10% CV, respectively. The fish in the T5 and T6 groups were exposed to 1/5 the 96-h LC₅₀ of penoxsulam (1.7896 mg/L) and fed the basal diet alone or the basal diet supplemented with 10% CV, respectively. Sub-acute penoxsulam exposure significantly altered hematological indices, as well as compromised the fish's immune defense mechanisms, including the phagocytic percentage, phagocytic index, nitric oxide production, immunoglobulin M levels and lysozyme, anti-trypsin and bactericidal activities subsequently decreasing O. niloticus's resistance to the Aeromonus sobria challenge and increasing disease symptoms and the mortality rate. Furthermore, sub-chronic penoxsulam exposure markedly altered growth performance, oxidant/antioxidant status and liver status and down-regulated the expression of interleukin-1β (IL-1β) and tumor necrosis-α (TNF-α). Interestingly, incorporating 10% CV into the diet protects fish against sub-acute penoxsulam-induced immunotoxicity via improvement of immune responses that increases the resistance against bacterial infection. Further, it improved the growth performance, oxidant/antioxidant status, liver status and markedly up-regulated immune-related gene expression, IL-1β and TNF-α, in the spleens of fish sub-chronically exposed to penoxsulam. These outcomes showed that dietary CV supplementation can protect the commercially valuable freshwater fish O. niloticus against penoxsulam toxicity and may be a potential feed supplement for Nile tilapia in aquaculture.

Immunomodulatory effect of Schisandra polysaccharides in cyclophosphamide-induced immunocompromised mice

As a strategy to prevent the well-known immunosuppressant effects of cyclophosphamide (Cyp), the immunomodulatory effects of the polysaccharide extract of the fruit of Schisandra chinensis (Turcz.) Baill. were investigated in the present study. The crude Schisandra polysaccharide (SCP) was obtained by water extraction and alcohol precipitation methods. The total carbohydrate, uronic acid and protein contents were determined using the phenol-sulfuric acid, m-hydroxydiphenyl and Bradford method, respectively. The monosaccharide composition of SCP was determined by high-performance liquid chromatography. ICR mice were randomly divided into control, model, low-dose SCP (0.4 mg/10 g), medium-dose SCP (0.8 mg/10 g) and high-dose SCP (1.6 mg/10 g) groups. The mice in the SCP groups were intragastrically administered SCP once a day for 21 days and those from the control and model groups were administered the same volume of distilled water. Subsequently, the mice in the model and SCP groups were intraperitoneally injected with Cyp (20 mg/kg) once a day for 5 days. The mouse leukocyte count in the peripheral blood as well as thymus and spleen indexes were determined, and the phagocytic function of macrophages was estimated using a carbon clearance test. The thymus and spleen were histomorphologically observed. The levels of tumor necrosis factor-α and interferon-γ were measured by ELISA. Furthermore, antibody formation and spleen lymphocyte proliferation were measured by the serum hemolysin and the MTT method, respectively. The apoptotic rate of splenic lymphocytes was determined by flow cytometric analysis. The results indicated that SCP prevents Cyp-induced impairment of the cellular, humoral and non-specific immunity, and may be an auxiliary immune enhancer for the prevention of immune hypofunction.