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 1ß/IL-1ß, TNF-α, transforming growth factor ß1/TGFß1, 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.

Effects of Chlorella vulgaris on tumor growth in mammary tumor-bearing Balb/c mice: discussing association of an immune-suppressed protumor microenvironment with serum IFNγ and IgG decrease and spleen IgG potentiation.

PURPOSE: Chlorella vulgaris (CV) has exhibited immune-enhancing and protective activities against cancer and infections. However, there is an increasing concern about the use of Chlorella species in human, regarding its various molecules with antigenic features found in infectious microorganisms. Our goal was to investigate the impact of higher concentrations of CV on tumor growth in spontaneous mouse mammary tumor (SMMT) models. METHODS: Balb/c mice were daily given CV powder at doses of 0, 200, or 300 mg/kg for 42 days (CONTROL, CV200, and CV300 groups, respectively; n = 6/group). On day 14, the SMMT was inoculated. Tumor volume (TV) and body weight (BW) were monitored on 5-day intervals following tumor challenge. On day 43, blood, spleen, lungs, and tumor tissues were collected. Histopathological examinations on lungs and tumor tissues were performed following hematoxylin-eosin staining. Intratumor expression of 27 genes was assessed by real-time PCR. Total IgG, IFNγ, and IL-4 levels in serum and spleen culture supernatant were measured by ELISA. RESULTS: The TV/BW index showed significant increase in the CV200 group compared to the CONTROL (p = 0.047). The CV200 tumors exhibited more malignant phenotype, higher angiogenesis rate, and lower peritumoral neutrophil and macrophage-to-lymphocyte infiltration ratio compared to the CONTROL. Serum concentrations of IFNγ, IL-4, and IgG were declined, and the spleen IFNγ and IgG production was higher in the CV200 compared to the CONTROL. The IL-1ß, IL-10, TGFß1, FOXP3, HO-1, Gr1, CD11b, PCNA, LCN2, iNOS2, VEGFR2, CD31, and CD105L expressions were markedly increased in the CV200 tumors compared to the CONTROL (p = 0.001, 0.002, 0.006, 0.021, 0.004, 0.030, 0.016, 0.031, 0.025, 0.008, 0.014, 0.022, and 0.037, respectively). The changes in cytokine, IgG and gene expression values considerably correlated with tumor size, as well as with each other. CONCLUSIONS: Our data provided evidence that C. vulgaris at a specific dose (200 mg/kg) promoted tumor growth in a mammary tumor model. This consequence might reflect an immune derangement in favor of developing a protumor microenvironment. However, this hypothesis needs to be further investigated in future.

Investigation of Chlorella vulgaris UTEX 265 Cultivation under Light and Low Temperature Stressed Conditions for Lutein Production in Flasks and the Coiled Tree Photo-Bioreactor (CTPBR).

Lutein has an increasing share in the pharmaceutical and nutraceutical market due to its benefits to eye health. Microalgae may be a potential source for lutein production while the expense limits the commercialization. In this study, a coiled tubular tree photobioreactor (CTPBR) design was investigated for cultivating the cold tolerant microalgae Chlorella vulgaris UTEX 265 under various conditions for lutein production. The influence and interaction of light irradiance strength, lighting cycle, and temperature on microalgae and lutein production efficiency at low temperature range were also studied in flasks via response surface method (RSM). The results demonstrated that 14 h day-light, 120 µmol photons m-2 s-1, and 10 °C was the optimal condition for algae growth and lutein production at low temperature experimental ranges. C. vulgaris UTEX 265 showed good potential to produce lutein in cold weather, and the optimum lutein production was contrary to the specific lutein content but corresponds to the trend of optimum growth. Additionally, fast growth (µ = 1.50 day-1) and good lutein recovery (11.98 mg g-1 day-1) in CTPBR were also achieved at the low irradiance stress condition and the low temperature photo-inhibition conditions.

[Effects of azithromycin and Chlorella vulgaris treatment on certain cytokine values and NK cell activity in an acute murine toxoplasmosis model]. / Akut toksoplazmozlu fare modelinde Azitromisin ve Chlorella vulgaris'in tedavi etkinliginin, NK aktivasyonu ve bazi sitokin degerlerinin arastirilmasi.

Toxoplasmosis is a common infection with a complicated treatment process. Azithromycin (AZT) is a macrolide antibiotic that can be effectively used in patients with cerebral and ocular toxoplasmosis and has fewer side effects. Chlorella vulgaris (CV), a single-cell green algae that contains nutrients and has various biological effects. CV extract (CVE) has been shown to have protective effects against infections via immune enhancement by increasing the cytotoxicity of NK cells, IL-12 and IFN-γ levels. The aim of this study was to investigate the protective effects of AZT and CV, individually and in combination, against acute toxoplasmosis in mice, and their effects on NK cell cytotoxixity, IL-12, IFN-γ, and IL-2 levels. Six groups of mice (Balb/c) were formed. With the exception of the healthy control (HC) group, all other groups were infected with 1 ml (11 x 104 trofozoit/ml) Toxoplasma gondii RH strain trophozoites. No further action was performed for infected control (IC) group. After 24 hours from trophozoite infection, CVE was given to CV group, AZT to azithromycin group and CVE + AZT combination to CV + AZT group by oral gavage for 6 days. All of the mice from IC, CV, AZT and CV + AZT groups were sacrified on the 8th day of the infection and serum, peritoneal fluid and spleen samples were collected. Trophozoite count of the groups were determined in all groups except HC group and the average growth inhibition activity was calculated by using the growth inhibition formula. In all groups IL-12, IFN-γ, IL-2 levels were measured with ELISA method and cytotoxicity of the NK cells were measured using Cytotox 96 Non-Radioactive Cytotoxicity Assay. The number of trophozoites were significantly lower in the CV group than the IC group (p< 0.001), and also significantly lower in CV + AZT combination group than the AZT group. According to the growth inhibition calculations CV treatment showed 88.6%, AZT treatment 98.46%, AZT + CV combination treatment 99.4% antiprotozoal activity against T.gondii compared with the IC group. NK cell cytotoxicity in the CV and the combination group were significantly higher than all the other groups (p< 0.001). IL-12 and IFN-γ levels were highest in IC group and the lowest in AZT + CV group. This situation has been linked to the fact that the severity of the infection has fallen considerably. IL-2 levels were significantly higher in CV, CV + AZT groups than in the other groups (p< 0.001). In our study, even CV administration alone caused a significant decline in infection.This may be related to the increased NK cytotoxicity, IL-2, IL-12 and IFN-γ levels. CV + AZT combination seems to be an effective treatment option than AZT alone, particularly in patients who are difficult to treat with common methods or in patients with immunosuppression.

Beneficial immunostimulatory effect of short-term Chlorella supplementation: enhancement of natural killer cell activity and early inflammatory response (randomized, double-blinded, placebo-controlled trial).

BACKGROUND: In vitro and animal studies have demonstrated that Chlorella is a potent biological response modifier on immunity. However, there were no direct evidences for the effect of Chlorella supplementation on immune/inflammation response in healthy humans. METHODS: This study was designed for an 8-week randomized, double-blinded, placebo-controlled trial: 5g of Chlorella (n=23) or Placebo (n=28) as form of tablets. Mainly, cytotoxic activities of Natural killer (NK) cells and serum concentrations of interferon-γ, interleukin-1ß and interleukin-12 were measured. RESULTS: After the 8-week, serum concentrations of interferon-γ (p<0.05) and interleukin-1ß (p<0.001) significantly increased and that of interleukin-12 (p<0.1) tended to increase in the Chlorella group. The increments of these cytokines after the intervention were significantly bigger in the Chlorella group than those in the placebo group. In addition, NK cell activities (%) were significantly increased in Chlorella group, but not in Placebo group. The increments of NK cell activities (%) were also significantly bigger in the Chlorella group than the placebo group. Additionally, changed levels of NK cell activity were positively correlated with those of serum interleukin-1ß (r=0.280, p=0.047) and interferon-γ (r=0.271, p<0.005). Signficantly positive correlations were also observed among the changed levels of serum cytokines; between interferon-γ and interleukin-1ß (r=0.448, p<0.001), between interleukin-12 and interleukin-1ß (r=0.416, p=0.003) and between interleukin-12 and interferon-γ (r=0.570, p<001). CONCLUSION: These results may suggest a beneficial immunostimulatory effect of short-term Chlorella supplementation which enhances the NK cell activity and produces interferon-γ and interleukin-12 as well as interleukin-1ß, the Th-1 cell-induced cytokines in healthy people.

Hematopoietic response of rats exposed to the impact of an acute psychophysiological stressor on responsiveness to an in vivo challenge with Listeria monocytogenes: modulation by Chlorella vulgaris prophylactic treatment.

In this study, we investigated the hematopoietic response of rats pretreated with CV and exposed to the impact of acute escapable, inescapable or psychogenical stress on responsiveness to an in vivo challenge with Listeria monocytogenes. No consistent changes were observed after exposure to escapable footshock. Conversely, the impact of uncontrollable stress (inescapable and psychogenical) was manifested by an early onset and increased severity and duration of myelossuppression produced by the infection. Small size CFU-GM colonies and increased numbers of clusters were observed, concurrently to a greater expansion in the more mature population of bone marrow granulocytes. No differences were observed between the responses of both uncontrollable stress regimens. CV prevented the myelossuppression caused by stress/infection due to increased numbers of CFU-GM in the bone marrow. Colonies of cells tightly packed, with a very condensed nucleus; in association with a greater expansion in the more immature population of bone marrow granulocytes were observed. Investigation of the production of colony-stimulating factors revealed increased colony-stimulating activity (CSA) in the serum of normal and infected/stressed rats treated with the algae. CV treatment restored/enhanced the changes produced by stress/infection in total and differential bone marrow and peripheral cells counts. Further studies demonstrated that INF-gamma is significantly reduced, whereas IL-10 is significantly increased after exposure to uncontrollable stress. Treatment with CV significantly increased INF-gamma levels and diminished the levels of IL-10. Uncontrollable stress reduced the protection afforded by CV to a lethal dose of L. monocytogenes, with survival rates being reduced from (50%) in infected rats to 20% in infected/stressed rats. All together, our results suggest Chlorella treatment as an effective tool for the prophylaxis of post-stress myelossupression, including the detrimental effect of stress on the course and outcome of infections.