Cudrania tricupidataBureau (CTB) Glycoprotein Inhibits Proliferation by Di(2-ethylhexyl) phthalate in Primary Splenocytes: Responses in Cell Proliferation Signaling

Relationship between phthalates exposures and hyperuricemia in U.S. general population, a multi-cycle study of NHANES 2007-2016

BACKGROUND

Phthalates exposure might cause kidney damage and a potential risk for hyperuricemia. However, direct evidence on phthalates and hyperuricemia is somewhat limited.

OBJECTIVE

To examine associations between 10 phthalates metabolites and hyperuricemia in a large-scale representative of the U.S.

METHODS

A cross-sectional study of 6865 participants aged over 20 from NHANES 2007-2016 was performed. All participants had complete data on ten phthalate metabolites (MECPP, MnBP, MEHHP, MEOHP, MiBP, cx-MiNP, MCOP, MCPP, MEP, MBzP), hyperuricemia, and covariates. We used multivariable logistics regression, restricted cubic splines (RCS) model, and Bayesian kernel machine regression (BKMR) models to assess single, nonlinear, and mixed relationships between phthalate metabolites and hyperuricemia. As a complement, we also assessed the relationship between phthalate metabolites and serum uric acid (SUA) levels.

RESULTS

The multivariable logistics regression showed that MECPP, MEOHP, MEHHP, MBzP, and MiBP were generally positively associated with hyperuricemia (P_FDR < 0.05), especially in MiBP (Q3 (OR (95 %): 1.31 (1.02, 1.68)) and Q4 (OR (95 %): 1.68 (1.27, 2.24)), compared to Q1). All ten phthalate metabolites had a linear dose-response relationship with hyperuricemia in the RCS model (P for non-linear >0.05). BKMR showed that mixed phthalate metabolites were associated with a higher risk of hyperuricemia, with MBzP contributing the most (groupPIP = 0.999, condPIP = 1.000). We observed the consistent results between phthalate metabolites and SUA levels in three statistical models. The relationship between phthalate metabolites and hyperuricemia remained in the sensitivity analysis.

CONCLUSIONS

The present study suggests that exposure to phthalates, individually or jointly, might increase the risk of hyperuricemia. Since hyperuricemia influences on the quality of life, more explorations are needed to confirm these findings.

Effects of di(2-ethylhexyl)phthalate exposure on 1,2-dimethyhydrazine-induced colon tumor promotion in rats

Di(2-ethylhexyl)phthalate (DEHP) may cause carcinogenicity in the liver; however, few have detailed on the potential effects of DEHP exposure on colorectal cancer. Male Sprague-Dawley rats received i.p. injections of 1,2-dimethylhydrazine (DMH) once-a-week for the first 4 weeks, and rats in each group were treated with DEHP through oral gavage daily for either 7, 10 or 15 weeks; after which, all rats were euthanized and their colons were assessed (a) morphologically for aberrant crypt foci (ACF) or tumors, (b) cytologically for mitotic index (MI), and (c) immunohistochemically for the expression of β-catenin, cyclooygenase (COX)-2, vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), cyclin D1, and c-myc. Our results indicated that the mean total ACF, tumor incidence, and MI were significantly higher in the DEHP-treated DMH compared to control and the DEHP-alone groups. The level of β-catenin and cyclin D1 was increased in DEHP-exposed rats. Expression of β-catenin, COX-2, VEGF, and cyclin D1 was significantly higher in the combined DMH and DEHP-treated rats by comparison to that of the DMH group. In conclusion, this study indicates that exposure to DEHP may exacerbate DMH-induced colon tumorigenesis and provides impetus to evaluate the effect of DEHP in conjunction with other carcinogens.

Protection against cyclophosphamide-induced myelosuppression by ZPDC glycoprotein (24 kDa)

Immunomodulatory agents are often used to reduce myelosuppression and enhance immune response for cancer treatment. Cyclophosphamide (CTX) can induce oxidative stress in bone marrow resulting in suppression of anti-oxdiantive enzymes and causes myelosuppression. We isolated glycoprotein from Zanthoxylum piperitum DC fruit (ZPDC), and it consists of a carbohydrate (18%) and a protein (82%). The objective of this study was to investigate its protective activity against CTX-induced myelosuppression in Balb/c (n=6/group). The mice were orally administrated by ZPDC glycoprotein (10 and 20 mg/kg, BW) for 1 week in the presence or absence of CTX. Intracellular reactive oxygen species (ROS), anti-oxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT)], cyclin kinase inhibitors (CKIs: p53, p21 and p27), cyclin D1/ cyclin dependent kinase (CDK) 4, PCNA and cytokines [interleukin (IL)-3, and granulocyte⁄ macrophage-colony-stimulating factor (GM-CSF)] were evaluated using biochemical activity, Western blot analysis, and ELISA. The results obtained from this study showed that CTX decreased spleen and thymic indices, bone marrow cellularity and expression of cyclin D1/CDK4 and PCNA, but it increased CKIs, whereas ZPDC glycoprotein (20 mg/kg, BW) resulted in vice versa in CTX-induced Balb/c. Expression of IL-3 and GM-CSF were normalized by ZPDC glycoprotein. Thus, this study suggested that ZPDC glycoprotein prevents oxidative stress and myelosuppression in CTX-induced mice and might be a potential immunomodulatory agent.