Yanmin Zou

Oxidative stress and immune related gene expression following exposure to di-n-butyl phthalate and diethyl phthalate in zebrafish embryos.

In the present study, we analyzed the oxidative stress related indices and immune related gene expression of zebrafish embryos after a short-term exposure to various concentrations of di-n-butyl phthalate (DBP), diethyl phthalate (DEP) and their mixture (DBP-DEP) from 4h post-fertilization (hpf) to 96hpf. Exposure to the chemicals was found to enhance the production of reactive oxygen species (ROS) and lipid peroxidation (LPO) in a concentration-dependent manner. Simultaneously, adaptive responses to DBP/DEP-induced oxidative stress were observed. The activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were all increased in a concentration-dependent manner. The transcription of innate immune related genes including interferon γ (IFNγ), interleukin-1β (IL1β), Myxovirus resistance (Mx), tumor necrosis factor α (TNFα), CC-chemokine, CXCL-clc, lysozyme (Lyz) and complement factor C3B (C3) were up-regulated upon DBP, DEP and their mixture exposure, suggesting the induction of immune response. In addition, co-exposure to DBP-DEP also induced antioxidant defense and immune response in zebrafish embryo. The results demonstrat that DBP/DEP exposure could induce the antioxidant and immune responses in zebrafish embryos.

Comparing anti-hyperglycemic activity and acute oral toxicity of three different trivalent chromium complexes in mice

Three different ligands (rutin, folate and stachyose) of chromium(III) complexes were compared to examine whether they have similar effect on anti-hyperglycemic activity as well as the acute toxicity status. Anti-hyperglycemic activities of chromium rutin complex (CrRC), chromium folate complex (CrFC) and chromium stachyose complex (CrSC) were examined in alloxan-induced diabetic mice with daily oral gavage for a period of 2 weeks at the dose of 0.5-3.0 mg Cr/kg. Acute toxicities of CrRC and CrFC were tested using ICR mice at the dose of 1.0-5.0 g/kg with a single oral gavage and observed for a period of 2 weeks. Biological activities results indicated that only CrRC and CrFC could decrease blood glucose level, reduce the activities of aspartate transaminase, alanine transaminase, alkaline phosphatase, and increase liver glycogen level. In acute toxicity study, LD(50) values for both CrRC and CrFC were above 5.0 g/kg. The minimum lethal dose for CrFC was above 5.0 g/kg, while that for CrRC was 1.0 g/kg. Anti-diabetic activity of those chromium complexes was not similar and their acute toxicities were also different. CrFC represent an optimal chromium supplement among those chromium complexes with potential therapeutic value to control blood glucose in diabetes and non-toxicity in acute toxicity.

Effects of di-n-butyl phthalate and diethyl phthalate on acetylcholinesterase activity and neurotoxicity related gene expression in embryonic zebrafish.

In the present study, zebrafish embryos were used to assess the neurotoxicity of di-n-butyl phthalate (DBP), diethyl phthalate (DEP) and their mixture. Four-hour post-fertilization (hpf) zebrafish embryos were exposed to various concentrations of DBP, DEP and their mixture (DBP–DEP) until 96 hpf. The transcriptions levels of selected neuron-related genes reported as neurotoxicity biomarkers were analyzed. The results showed that transcripts of growth associated protein 43 (gap43), embryonic lethal abnormal vision-like 3 (elavl3), glial fibrillary acidic protein (gfap), myelin basic protein (mbp), α1-tubulin and neurogenin1 (ngn1) were significantly up-regulated after DBP, DEP and DBP–DEP mixture exposure. In addition, acetylcholinesterase activity was significantly inhibited in the embryos. These results indicate that DBP and DEP have the potential neurotoxicity in zebrafish embryos.

Hollow-fiber-supported liquid-phase microextraction using an ionic liquid as the extractant for the pre-concentration of bisphenol A, 17-β-estradiol, estrone and diethylstilbestrol from water samples with HPLC detection.

A new method for the determination of four endocrine disrupting compounds (EDCs) (bisphenol A, 17-β-estradiol, estrone and diethylstilbestrol) in water samples has been developed using polypropylene hollow-fiber-supported ionic liquid (IL, 1-Octyl-3-methylimidazolium hexafluorophosphate, [C8MIM][PF6]) microextraction [HF-liquid-phase microextraction (LPME)] combined with high-performance liquid chromatography (HPLC)/UV. This method was used to investigate pollutants in surface water, on the Neijiang River, located at Zhenjiang, Jiangsu Province. Several parameters (sample pH, volume of accepter phase, ionic strength) were investigated. Under the optimum extraction conditions (sample pH, 2.0; volume of extraction solvent, 2.5 μL; ionic strength, 2.57) the proposed method offered: good linearity range, 0.15-100 μg L(-1), with the correlation coefficients (r(2)) of 0.9996, 0.9994, 0.9990 and 0.9984, respectively; low limits of detection, 0.03, 0.05, 0.10, 0.05 μg L(-1) (S/N = 3) for bisphenol A, 17-β-estradiol, estrone and diethylstilbestrol, respectively; good reproducibility (relative standard deviation (RSD), 8.41, 7.61, 9.00, 7.22%, respectively, n = 5); satisfactory recoveries (80.2-107.1%, n = 5); and high enrichment factors, 5,240, 3,693, 2,425 and 2,086, were achieved, for the four chemicals, respectively. Using the proposed HF-LPME, among 15 sampling sites along Neijiang River, bisphenol A, diethylstilbestrol and 17-β-estradiol were detected in some sites, all of which were the near suburban sampling sites. The results indicate that the role of municipal sewage is an important source of EDC contamination.

Application of Three Phase Hollow Fiber LPME Using an Ionic Liquid as Supported Phase for Preconcentration of Bisphenol A and Diethylstilbestrol from Water Sample with HPLC Detection

A new method for the determination of trace bisphenol A (BPA) and diethylstilbestrol (DES) in water samples has been developed by using three phase hollow fiber liquid-phase microextraction (HF-LPME) and an ionic liquid (IL, 1-Octyl-3-methylimidazolium hexafluorophosphate, [C8MIM][PF6]) as supported phase (IL-HF-LPME) combined with high performance liquid chromatography/ultraviolet spectrophotometry (HPLC/UV). The optimized microextraction conditions were as follows: [C8MIM][PF6] was used as the extraction solvent, pH 10 NaOH solution, 5 µL, as acceptor phase; 20 mL water sample with NaCl (5%, w/v) as donor phase and the extraction time was 30 min (stirring rate 200 rpm, 25°C). Under the optimal extraction conditions, the proposed method offered: good linearity range, 0.30–100 µg L−1, with correlation coefficients (r 2) of 0.9996 and 0.9988; low detection limit, 0.20 and 0.05 µg L−1 (S/N = 3) for BPA and DES, respectively; good reproducibility (relative standard deviation, RSD, 7.28% and 8.45%, respectively, n = 5); high enrichment factor, 850 and 624, respectively. The method was used to analyze real water samples, and satisfactory recoveries (75.4–99.2%) were obtained, which confirmed that the developed method was simple and environmentally friendly for the determination of BPA and DES in aquatic systems. Meanwhile, it was found that humic acid had no obvious influence on enrichment factor.

A multivariate assessment of innate immune-related gene expressions due to exposure to low concentration individual and mixtures of four kinds of heavy metals on zebrafish (Danio rerio) embryos

Concerns over the potential health effects of mixtures of low concentration heavy metals on living organisms keep growing by the day. However, the toxicity of low concentration metal mixtures on the immune system of fish species has rarely been investigated. In this study, the zebrafish model was employed to investigate the effect on innate immune and antioxidant-related gene expressions, on exposure to environmentally relevant concentrations of individual and mixtures of Pb (0.01 mg/L), Hg (0.001 mg/L), As (0.01 mg/L) and Cd (0.005 mg/L). Messenger-RNA (mRNA) levels of IL1β, TNF-α, IFNγ, Mx, Lyz, C3B and CXCL-Clc which are closely associated with the innate immune system were affected after exposing zebrafish embryos to metals for 120 h post fertilization (hpf). Individual and mixtures of metals exhibited different potentials to modulate innate-immune gene transcription. IL1β genes were significantly up regulated on exposure to Pb + As (2.01-fold) and inhibited on exposure to Pb + Hg + Cd (0.13-fold). TNF-α was significantly inhibited on exposure to As (0.40-fold) and Pb + As (0.32-fold) compared to control. Metal mixtures generally up regulated IFNγ compared to individual metals. Additionally, antioxidant genes were affected, as CAT and GPx gene expressions generally increased, whiles Mn-SOD and Zn/Cu-SOD reduced. Multivariate analysis showed that exposure to individual metals greatly influenced modulation of innate immune genes; whiles metal mixtures influenced antioxidant gene expressions. This suggests that beside oxidative stress, there may be other pathways influencing gene expressions of innate immune and antioxidant-related genes. Low concentration heavy metals also affect expression of development-related (wnt8a and vegf) genes. Altogether, the results of this study clearly demonstrate that low concentration individual and mixtures of metals in aquatic systems will greatly influence the immune system. It is indicative that mechanisms associated with toxicity of metal mixtures is complex, however, further studies to elucidate them are ongoing in our research laboratory.

Purification, characterization and immunoregulatory activity of a polysaccharide isolated from Hibiscus sabdariffa L.

BACKGROUND Hibiscus sabdariffa L. is not only used traditionally as a component of herbal drinks, beverages and flavoring agents but also as a herbal medicine in the drug industry. Bioactive polysaccharides are important constituents of H. sabdariffa that may contribute to the plants beneficial effects. This study was designed to investigate the structural characteristics of a water-soluble polysaccharide from H. sabdariffa, HSP41, and its immunoregulatory activity on RAW264.7 cells. RESULTS HSP41 was mainly composed of arabinose, xylose and mannose at a molar ratio of 1:1.34:15.6, with an average molecular weight of 3.3 × 105  Da. Fourier transform infrared (FTIR) spectra exhibited absorption peaks characteristic of HSP41. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed the amorphous form and aggregation conformation of HSP41 respectively. HSP41 significantly induced interleukin 1β (IL-1β) and inducible nitric oxide synthase (iNOS) expression in RAW264.7 cells in vitro, promoting an increase in nuclear factor kB p65 (NF-kB p65) levels in the nucleus. CONCLUSION The results indicated that HSP41 up-regulated the immune response by stimulating RAW264.7 cell activity. HSP41, a promising immunoregulator, possibly contributes to the health benefits of H. sabdariffa and might have potential applications in health food or medicine.

Water-Soluble Polysaccharides from Leaves of Abelmoschus esculentus: Purification, Characterization, and Antioxidant Activity

Two water-soluble polysaccharides were obtained from the leaves of Abelmoschus esculentus using aqueous extraction and purification with DEAE-52 and Sephadex G-100. AEP-11 (1.9 × 105 Da) consisted of D-arabinose, D-xylose, D-glucose, D-mannose, and D-galactose in a 2.9:3.1:0.3:0.4:3.4 ratio. AEP-22 (1.6 × 106 Da) consisted of D-arabinose, xylose, D-mannose, and galactose in a 4.7:0.8:0.6:3.9 ratio. AFM and Congo red indicated that the enhanced flexibilities of AEP-11 and AEP-22 chains could lead to agglomerated morphologies and may further confirm random coils instead of triple helical conformations. CD revealed the presence of disordered structure in AEP-22 compared with the ordered structure in AEP-11. In antioxidant activity assay, AEP, AEP-11, and AEP-22 all exhibited strong radical-scavenging capacities (AEP > AEP-11 > AEP-22) and obvious reducing power.

Study on preparation of Prunella dispersible tablets

Objective To study the prescription and preparation technology of Prunella ethanol extract dispersible tablets. Methods Take disintegration time as indexes, the prescription and preparation technology were optimized by an orthogonal design. The hardness, suspended uniformity, dissolution were investigated and preliminary stability were tested through accelerated test. Results The optimum prescription was: active components 40%, loading agent MCC 50%, disintegrating agent PVPP 8% and lubricant magnesium stearate 1%. The dispersible tablets were prepared under the optimum technology with hardness 5.1±0.3 kg·mm−2, satisfactory suspended uniformity, stable quality and accumulated dissolution in 30 min was more than 90%. Conclusion The prescription for the dispersible tablets was reasonable and its technology is feasible, which meets the quality requirement of the disperse tablets.