Pumpkin Skin Polysaccharide-Zn(II) Complex: Preparation, Characterization, and Suppression of Inflammation in Zebrafish.

In this study, pumpkin (Cucurbita moschata) skin polysaccharide-zinc(II) (PSP-Zn) complex was successfully prepared. The structure and physicochemical properties of PSP and PSP-Zn were analyzed. The anti-inflammatory activity of PSP and PSP-Zn was investigated in zebrafish larvae induced by copper sulphate. PSP and PSP-Zn consisted of rhamnose, arabinose, galactose, glucose, and galacturonic acid. The molecular weight (Mw) of PSP and PSP-Zn were 3.034 × 106 and 3.222 × 106 Da, respectively. Fourier transform infrared spectrum (FT-IR) and circular dichroism (CD) analysis results suggested that the chemical modification of zinc might occur through hydroxyl groups of PSP. The PSP-Zn complex had lamellar texture, smooth surface morphology, and larger particle size. X-ray Diffraction (XRD) analysis revealed that both PSP and PSP-Zn were semi-crystalline substances. PSP-Zn solution showed superior stability in a weak acid and alkaline environment, especially at pH = 6.0. Moreover, PSP and PSP-Zn showed a good inhibitory effect on inflammation cells in zebrafish. Real-time quantitative polymerase chain reaction (RT-PCR) result suggested that the anti-inflammatory mechanism of PSP and PSP-Zn were through downregulation of the expression of nitric oxide synthase 2b (nos2b), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and nuclear factor-kappa B2 (NF-κB2). The present study indicated that PSP-Zn is expected to be a safe and efficient novel zinc supplement with anti-inflammatory activity.

Distribution and source identification of polychlorinated naphthalenes in bees, bee pollen, and wax from China.

Polychlorinated naphthalenes (PCNs) are highly toxic and persistent organic pollutants that can cause adverse effects in the environment and on human health. PCNs have been detected in remote areas because of their long-range transportation. Bees and bee products are commonly used as biomonitors for various pollutants in the environment. However, information on PCNs in apiaries is scarce. The aim of this study was to evaluate the occurrences of PCNs in bees and bee products from apiaries located in different geographical regions of China, and to identify potential pollution sources and assess exposure risks to humans. Our results showed that the average Σ75PCNs concentrations in bees, pollen, and wax were 74.1, 96.3, and 141 pg/g dry weight, respectively. The homologue and congener profiles of PCNs in bees, pollen, and wax were similar, and di- and tri-chlorinated naphthalenes (>60%) were the predominant homologues. The concentrations and distributions of PCNs in bees, pollen, and wax varied among different geographical regions, but their occurrences were correlated with PCN metallurgical sources in China. The health risks of PCNs in pollen were evaluated, and both carcinogenic and non-carcinogenic risks of PCNs exposure to humans through the diet were low.

Concentration and risk assessment of PCNs in green tea in different locations in China.

Polychlorinated naphthalenes (PCNs) were added to the Stockholm Convention list of persistent organic pollutants in 2015. PCNs are mainly unintentionally produced during industrial processes nowadays, and can be widely found in environmental media and foodstuffs. Dietary intake is the primary pathway for human exposure to PCNs. PCNs in different categories of foodstuffs have been reported. However, little information on PCN concentrations in green tea, a popular beverage worldwide is available. In this study, all 75 PCN congener concentrations and distributions in green tea samples (n = 102) from 11 regions in China were determined, and risk assessment of human exposure to PCNs through tea consumption was conducted. The PCN concentrations in all the green tea samples were 3.62-175 pg/g dry weight (mean 36.1 pg/g dry weight). Similar PCN homolog and congener profiles were found in green tea samples from different areas. The dominant PCN homologs in all of the green tea samples were di-CNs, tetra-CNs, and tri-CNs. No direct relationships were found between PCN emission sources and PCN concentrations in the green tea samples. The brewing technique could affect the PCN concentrations and homolog profiles in tea leaves. PCNs in green tea from China were found to pose little risk to humans.

Short- and medium-chain chlorinated paraffins in green tea from 11 Chinese provinces and their migration from packaging.

Chlorinated paraffins (CPs) have been found to occur ubiquitously in foodstuff of both animal and plant origin. However, limited information is available on the content of CPs in green tea, one of the most commonly consumed beverages worldwide. Herein, 107 commercial green tea samples originating from 11 provinces of China, were collected to study the occurrence of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively). The concentration of SCCPs in all green tea samples ranged from 4.99 to 717 ng/g (mean: 55.7 ng/g), while MCCPs ranged from 2.55 to 543 ng/g (mean: 33.5 ng/g). CP profiles in green tea samples from different provinces exhibited no regional differences. To identify the potential sources of CPs in green tea, 19 tea packaging samples were collected and analyzed, showing that SCCPs and MCCPs existed at much higher concentrations in the tea packaging material than in the teas. Migration tests indicated that CPs could migrate from packaging into teas during storage, with the migration velocity and efficiency of SCCPs being higher than MCCPs.

Laser irradiation promotes the proliferation of mouse pre-osteoblast cell line MC3T3-E1 through hedgehog signaling pathway.

Low-level laser could promote osteoblast proliferation, and it has been applied in clinical practice to promote wound healing and tissue regeneration. However, the mechanism related to laser irradiation remains unclear. This study aimed to investigate the effects of low-level laser irradiation on the cell proliferation and the expressions of hedgehog signaling molecules Indian hedgehog (Ihh), Ptch, and Gli in vitro. In our present study, the MTT method was used to evaluate the effect on cell proliferation of laser irradiation on MC3T3-E1 cells. And cell cycle was examined by flow cytometry. Gene and protein expressions of hedgehog signaling molecules, including Ihh, Ptch, Smoothened (Smo), and Gli, were examined by qRT-PCR and western blot analysis. The results showed that laser irradiation at dosage of 3.75 J/cm2 enhances the proliferation of MC3T3-E1 cells compared with control groups (p = 0.00). Moreover, laser irradiation (3.75 J/cm2) increased the cell amount at S phase (p = 0.00). In addition, the expressions of Ihh, Ptch, Smo, and Gli were significantly increased compared to the control during laser irradiation (3.75 J/cm2)-induced MC3T3-E1 osteoblast proliferation. After adding the hedgehog signaling inhibitor CY (cyclopamine), cell proliferation and Ihh, Ptch, Smo, and Gli expressions were inhibited (p = 0.00), and the cell amount at S phase was reduced compared with combination groups (p = 0.00). These results indicated that laser irradiation promotes proliferation of MC3T3-E1 cells through hedgehog signaling pathway. Our findings provide insights into the mechanistic link between laser irradiation-induced osteogenesis and hedgehog signaling pathway.

Cooking process: a new source of unintentionally produced dioxins?

To improve understanding of human background exposure to dioxins, the influence of cooking on dioxin concentrations in food has received much attention. Studies have focused on changes in the distribution of dioxins that originate from raw foods. However, the possibility of dioxin formation during cooking has been neglected. In this study, cooking experiments were designed to investigate the generation of dioxins during cooking at high temperature and with flavorings containing organic chlorine. Solid, liquid, and gas phase samples were collected during cooking. The results indicate that dioxins can be generated during some cooking processes, such as burning, or when cooking with reactive organic chlorides, and the dioxins are more likely to be present in the smoke (gas phase) than the edible portion (solid and liquid phases). Thus, more attention should be given to cooking of raw foods and organic chlorine-containing flavorings at high temperature. Maintaining good ventilation during cooking is also necessary to reduce human exposure risk to dioxins.