The flame retardant DE-71 (a mixture of polybrominated diphenyl ethers) inhibits human differentiated thyroid cell function in vitro.

BACKGROUND: Normal thyroid function is essential for general growth and metabolism, but can be affected by endocrine disrupting chemicals (EDCs). Polybrominated diphenyl ethers (PBDEs) have been used worldwide to reduce flammability in different materials and are suspected to be EDCs. The production of the commercial Penta- and OctaBDE mixtures is banned, but DecaBDEs and existing products may leak PBDEs into the environment. Our aim was to investigate the effect of the PentaBDE mixture DE-71 on human thyroid cells in vitro. MATERIALS AND METHODS: Primary human thyroid cells were obtained as paraadenomatous tissue and cultured in monolayers. The influence of DE-71 on cyclic adenosine monophosphate (cAMP) and thyroglobulin (Tg) production was examined in the culture medium by competitive radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Real-time quantitative PCR analysis of thyroid-specific genes was performed on the exposed cell cultures. PBDE concentrations were determined in cellular and supernatant fractions of the cultures. RESULTS: DE-71 inhibited Tg-release from TSH-stimulated thyrocytes. At 50 mg/L DE-71, mean Tg production was reduced by 71.9% (range: 8.5-98.7%), and cAMP by 95.1% (range: 91.5-98.8%) compared to controls). Expression of mRNA encoding Tg, TPO and TSHr were significantly inhibited (p<0.0001, p = 0.0079, and p = 0.0002, respectively). The majority of DE-71 added was found in the cell fraction. No cytotoxicity was found. CONCLUSIONS: DE-71 inhibited differentiated thyroid cell functions in a two phase response manner and a concentration-dependent inhibition of Tg and cAMP production, respectively, as well as expression of mRNA encoding Tg, TPO and TSHr. Our findings suggest an inhibiting effect of PBDEs on thyroid cells.

Lactobacillus reuteri supplements do not affect salivary IgA or cytokine levels in healthy subjects: A randomized, double-blind, placebo-controlled, cross-over trial.

OBJECTIVES: To evaluate the effect of daily ingestion of probiotic lactobacilli on the levels of secretory IgA (sIgA) and selected cytokines in whole saliva of healthy young adults. MATERIALS AND METHODS: The study group consisted of 47 healthy adults (18-32 years) who volunteered for a randomized, double-blind, placebo-controlled, cross-over trial after informed consent. During intervention, the subjects ingested two lozenges per day containing two strains of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) or placebo lozenges. The intervention and wash-out periods were 3 weeks. Saliva samples were collected at baseline, immediately after each intervention period and 3 weeks post-intervention. ELISA was used to measure sIgA and luminex technology was used to measure the interleukins (IL)-1ß, IL-6, IL-8 and IL-10. For statistical analyses a mixed ANOVA model was employed to calculate changes in the salivary outcome variables. RESULTS: Forty-one subjects completed the study and reported a good compliance. No significant differences in the concentrations of salivary sIgA or cytokines were recorded between the L. reuteri and placebo interventions or between baseline and 3 weeks post-intervention levels. No side- or adverse effects were reported. CONCLUSIONS: Supplementation with two strains of the probiotic L. reuteri did not affect sIgA or cytokine levels in whole saliva in healthy young adults. The results thereby indicate that daily oral supplementation with L. reuteri do not seem to modulate the salivary oral immune response in healthy young subjects (ClinicalTrials.gov NCT02017886).

Triterpene acids from rose hip powder inhibit self-antigen- and LPS-induced cytokine production and CD4⁺ T-cell proliferation in human mononuclear cell cultures.

A triterpene acid mixture consisting of oleanolic, ursolic and betulinic acid isolated from a standardized rose hip powder (Rosa canina L.) has been shown to inhibit interleukin (IL)-6 release from Mono Mac 6 cells. The present study examined the effects of the triterpene acid mixture on the cytokine production and proliferation of CD4⁺ T cells and CD19⁺ B cells induced by a self-antigen, human thyroglobulin and by lipopolysaccharide in cultures of normal mononuclear cells. The triterpene acid mixture inhibited the production of tumor necrosis factor-α and IL-6 with estimated IC50 values in the range 35-56 µg/mL, the Th1 cytokines interferon-γ and IL-2 (IC50 values 10-20 µg/mL) and the antiinflammatory cytokine IL-10 (IC50 values 18-21 µg/mL). Moreover, the mixture also inhibited CD4⁺ T-cell and CD19⁺ B-cell proliferation (IC50 value 22 and 12 µg/mL, respectively). Together, these data demonstrate that oleanolic, ursolic and betulinic acid are active immunomodulatory constituents of the standardized rose hip powder. However, since the estimated IC50 values are in the µg/mL range, it is questionable whether the content of the triterpene acids in the standardized rose hip powder, alone, can explain the reported clinical effects.

Enhancement of natural killer cell activity in healthy subjects by Immulina®, a Spirulina extract enriched for Braun-type lipoproteins.

Immulina®, a commercial extract of Arthrospira (Spirulina) platensis is a potent activator of THP-1 monocytes and CD4+ T cells IN VITRO and enhances several immunological functions in mice. We further characterized Immulina® by determining that Braun-type lipoproteins are responsible for a major portion of the IN VITRO monocyte activation exhibited by this material. In order to understand the effect of Immulina® on NK cell activity, a pilot study was conducted on ten healthy North American individuals who supplemented their diet with Immulina® (400 mg/day) for seven days. We observed a 40% average increase in the killing of K562 tumor cells by NK cells (p < 0.01) after Immulina® supplementation. In a separate placebo-controlled, crossover study involving 11 healthy Danish subjects, we observed increased mRNA expression of the NK cell marker NKG2D by 37% (p = 0.02) and by 55% (p = 0.0003) after administration of Immulina® (200 mg and 400 mg per day, respectively) for seven days. The mRNA expression of the NK- and T-cell marker perforin increased by 75% (p = 0.008) after administration of 400 mg Immulina® per day. Both markers displayed significant dose-dependent effects (p = 0.0003 and p = 0.02, respectively). The ratio between CD56 (bright) and CD56 (dim) NK cells was not affected by Immulina® administration. In summary, two independent studies showed enhancement of NK cell activity following administration of Immulina® for seven days.

Enhancement of human adaptive immune responses by administration of a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis.

The effect of consumption of Immulina, a high-molecular-weight polysaccharide extract from the cyanobacterium Arthrospira platensis, on adaptive immune responses was investigated by evaluation of changes in leukocyte responsiveness to two foreign recall antigens, Candida albicans (CA) and tetanus toxoid (TT), in vitro. Consumption of Immulina by 11 healthy male volunteers caused an immediate, but temporary, increase of CA-induced CD4+ T-helper (Th) cell proliferation (P < .02). TT-induced Th cell proliferation was increased in individuals over 50 years of age (P < .05) and correlated with age (P < .02). Consumption for 8 days enhanced the CA-induced B cell proliferation (P < .02), but after 56 days a diminution was seen (P < .03). The CA-elicited production of the Th1 cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, and interferon (IFN)-gamma was increased after Immunlina administration for 3 days (P < .001, < .03, and < .007, respectively), and increased IL-2 production persisted after 56 days (P < .004). The TNF-alpha, IFN-gamma, and IL-6 responses to TT were enhanced after 8 and 14 days (P < .002-.05), while IL-5 responses increased significantly within 3 days (P < .04) and fell below baseline levels after 14 days (P < .008). Conversely, consumption for 3 days inhibited the IL-4 responses to both CA and TT (P < .008 and P < .03, respectively). No effects on IL-10 responses were observed. Upon addition to normal mononuclear cells in vitro, Immulina elicited strong TNF-alpha, IL-1beta, and IL-6 responses, indicating that it acts by inducing a pro-inflammatory state. Taken together, the data suggest that Immulina causes an age-dependent, temporary enhancement of adaptive immune responses.