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Objective@#To analyze liquid milk exposure of thiocyanate among Chinese population and preliminarily assess its health risk.@*Methods@#A total of 2 059 raw milk samples were collected during 2013 and 2014 from 12 Chinese provinces, New Zealand and Netherlands. Farms were chosed according to the main sources of dairy companies, the distribution of farms and the yield of milk. Content of thiocyanate were detected by ion chromatography. Liquid milk consumption data were taken from Chinese beverage and alcoholic beverage consumption survey in 18 cities or counties in 9 provinces, including 16 775 subjects older than 3. A simple distribution model was used to estimate the exposure of thiocyanate from liquid milk. The tolerable daily intake (TDI) of thiocyanate was made 0.08 mg·kg-1·d-1. Then the exposures of different age groups were compared with TDI.@*Results@#Finally, 1 331 samples out of 2 059 were detected to contain thiocyanate. The detection rate was 65%. The average concentration of thiocyanate was 2.11 mg/kg, with a range of 0.10-16.20 mg/kg. The general population's consumption of thiocyanate by drinking liquid milk was 0.001 mg · kg-1 · d-1, which was lower than TDI. The P95 of general population and consumers were 0.009 mg · kg-1 · d-1 and 0.020 mg·kg -1·d-1 respectively, which were also lower than TDI. Mean exposures of population aged 3-6, 7-12, 13-17, 18-59 as well as elderly aged 60 and above were 0.007, 0.003, 0.002, 0.001 and 0.001 mg · kg-1·d-1 respectively, which were all lower than TDI.@*Conclusion@#The results suggested that the health risk of thiocyanate exposure by drinking liquid milk among Chinese population was at a low level. However, milk products for children deserve more concern.
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Background Sulforaphane (SFN) is an effective chemopreventive agent and can regulate the biological molecular mechanisms to inhibit the overgrowth of cells.Autophagy is a biological process of maintaining cellular internal environment.Understanding the affection of SFN to biological behavior of human lens epithelial cells (LECs) and the association of SFN with autophagy is helpful for the prevention and target treatment of posterior capsule opacification (PCO).Objective This study was to investigate the eradication effeccts of SFN on residual lens cell population in vitro posterior capsule opacification (PCO) model and evaluate the mechanism of SFN-induced cell death.Methods In vitro human capsular bag models were generated from fresh donor eyes by phacoemulsification and were cultured in EMEM containing 2％ fetal bovine serum (FBS).Different concentrations of SFN (0,1,10 and 100 μ mol) were added in the medium for 30 days respectively according to grouping,and the growth of LECs was observed by optical microscope and immunofluorescence technique.FHL124,a human LEC line,was cultured with EMEM containing 5％ FBS and divided into 0,1,10,30 and 100 μmol SFN groups.Lactate dehydrogenase (LDH) release rate in the medium was detected to evaluate cell damage/death.The migration of the cells on capsular bags was assessed by scratch test.The ultrastructure and number of autophagosomes were examined under the transmission electron microscope.The expression of LC3 in the cells were detected using Western blot in the presence or absence of autophagy inhibitors.Results The cell coverage rates on the capsular bags were significantly lower in the 10 and 100 μ mol/L SFN groups than those in the 0 and 1 μmol/L SFN groups,with a statistically significant difference among the groups (F =48.57,P ＜ 0.01).Immunofluorescence showed that the density of F-actin-and Vimentin-positive cells was evidently decreased in the 10 and 100 μmol/L SFN groups compared with 0 and 1 μ mol/L SFN groups.The releasing levels of LDH (absorbancy) were 0.19± 0.03,0.39±0.06,0.56±0.07,0.68±0.08 and 0.89±0.09 in the 0,1,10,30 and 100 μ mol/L SFN groups,respectively,and the releasing level of LDH was gradually increased in the 10 and 100 μ mol/L SFN groups in comparison with the 1 μmol/LSFN group (all at P＜0.01).With the increase of SFN concentration,the reduction rate of scratched area decreased with the increase of SFN concentration,and the decrease of scratch area was significantly lower than that of adjacent low mass concentration group and the differences were statistically significant (P＜0.05).The relative expressions of LC3-Ⅱ protein were 0.423±0.003,14.543±0.024,0.668±0.024 and 0.576±0.056 in the blank control group,SFN group,SFN + 3-MA group and 3-MA group,respectively,and the relative expressions of LC3-Ⅱ protein were significantly lower in the SFN+3-MA group and 3-MA group than those in the SFN group (all at P＜0.01).The number of autophagosomes was 4.07±0.32,4.13±0.34,9.21 ±0.53 and 21.02± 1.34 in the blank control group,and 1,10,100 μmol/L SFN groups,and the number of autophagosomes in the 10 and 100 μ mol/L SFN groups was significantly higher than that in the blank control group and 1 μmol/L SFN group (all at P＜0.01).Conclusions SFN mediates LECs death by promoting autophagy in ex vivo capsular bags,and SFN may be a novel agent of potential chemopreventive and target treatment for PCO.
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Background Evidences indicated that oxidative stress damage is an essential pathological process in primary open angle glaucoma.Sulforaphane (SFN) can play an antioxidative stress role to many tissues and cells by activating Nrf2/ARE single pathway.However,whether SFN has a protective role to oxidative stress induced damage of trabecular meshwork cells is still unclear.Objective This study was to investigate the antioxidant effect of SFN against H2O2-induced oxidative damage in bovine trabecular meshwork cells.Methods Trabecular cells were isolated from fresh black bovine eyeballs and primarily cultured and passaged.The third generation of cells were incubated to 96-well dish at a density of 1 ×103/well for 24 hours and divided into 4 groups.The cells were incubated using 100 μl serum-free medium in the blank control group.Oxidative damage models were established by adding 100 μmol/L H2O2(100 μl) in medium in the H2O2 group.The cells were cultured with the medium containing 10 μmol/L SFN (100 μl) in the SFN group,and 100 μl H2O2 at the final concentration of 100 μmol/L was added in the SFN-treated cell medium in the SFN +H2O2 group.The cell vitality in various groups was assayed by using cell counting kit-8 (CCK-8).The apoptosis rate of the cells was detected by Annexin V-FITC/PI double-staining with flow cytometry.Results Cultured cells showed a spindle shape with uniform size,abundant cytoplasm,numberous pigmented particles and big nucleolus.The relative cell vitality reduced to (67.00± 1.27)％ and (80.00±6.25)％ in the H2O2 group and SFN+H2O2 group in comparison with 100％ in the blank control group,and the cell vitality in the SFN+ H2O2 group was lower than that in the SFN group but higher than that in the H2 O2 group (both at P＜0.01).The mean apoptosis rate was (11.33 ±0.77) ％,(32.31 ± 1.03) ％,(10.44 ±0.68) ％ and (17.68 ±0.21) ％ in the blank control group,H2 O2 group,SFN group and SFN+H2O2 group,respectively,showing a significant difference among the groups (F=539.96,P＜0.01),and the apoptosis rate in the SFN+H2O2 group was significantly lower than that in the H2O2 group but higher than that in the blank control group and SFN group (all at P＜0.01).Conclusions SFN can improve the antioxidative stress ability of trabecular meshwork cells and alleviate the damage induced by oxidative stress.
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Objective To evaluate the effects of sulforaphane preconditioning on cognitive dysfunction induced by sevoflurane anesthesia in aged rats.Methods Thirty Sprague-Dawley rats,aged 22 months,weighing 380-560 g,were randomly divided into 3 groups (n =10 each) using a random number table:control group,sevoflurane group (Sev group),and sulforaphane group (Sul group).In group Sul,sulforaphane25 mg/kg was administered by oral gavage once a day for 7 consecutive days,while the equal volume of distilled water was given instead of sulforaphane in Sev and C groups.Groups Sev and Sul inhaled 3％ sevoflurane in oxygen (2.5 L/min) and group C inhaled air (100 min/d) for 5 consecutive days starting from the end of gavage.At 24 h after sevoflurane inhalation,cognitive function was detected using Morris water maze and open field tests.The escape latency,frequency of crossing the original platform,the number of crossing the grid,the number of standing on the back legs and the time the animals spent in the central square were recorded.Results Compared with group C,the frequency of crossing the original platform,the number of crossing the grid,and the number of standing on the back legs were significantly reduced,the time the animals spent in the central square and escape latency on 1st day were prolonged and no significant changes were found in the escape latency on 2nd-4th days in group Sev.Compared with group Sev,the frequency of crossing the original platform,the number of crossing the grid,and the number of standing on the back legs were significantly increased,and the time the animals spent in the central square and escape latency on 1st day were shortened.Conclusion Sulforaphane preconditioning can improve the cognitive dysfunction induced by sevoflurane anesthesia in aged rats.
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Objective To investigate the effect of sulforaphane on 1-methyl-4-phenylpyridinium (MPP +)-induced cell viability loss in cultured PC12 cells and to explore the possible mechanism.Methods MPP + induced damage in PC12 cells was prepared as oxidative damage model.Sulforaphane (0.5,1.O,2.5,5.0 and 10.0 μmol/L) was added in each group cell growth medium.Subsequent experiments were divided into 4 groups:(A) normal control group,(B) sulforaphane group,(C) MPP+ injury group,(D)sulforaphane pretreatment + MPP+ injury group.Cell viability was detected by MTT assay,and the sulforaphane pretreatment PC12 cell viability was observed in different concentrations.Flow cytometry was used to detect changes in the rate of apoptosis in different packet PC12 cells,and protein expression levels of nuclear factor erythroid2-related factor 2 (Nrf2),heme oxygenase (HO-1) and human NAD (P) H dehydrogenase,quinone 1 (NQO1) were detected by Western blot when the PC12 cells were incubated with sulforaphane (2.5 μmol/L) and (or) MPP+ (500 μmol/L) for 24 h in vitro.Results Compared to control group (cell survival rate was 98.70％),the survival percents of PC12 cells were significantly decreased in MPP+-treated group (58.16％).A significant difference was showed between group A and C (F =21.83,P ＜ 0.05),and the cell survival rate in group D was significantly improved.Compared to control group,the rate of apoptosis in MPP+ injury group was increased,and the rate of apoptosis after pretreatment of the sulforaphane was significantly reduced.Compared to MPP+ injury group,the levels of Nrf2,HO-1 and NQO1 protein expression were significantly increased in sulforaphane pretreatment group.Conclusion Sulforaphane have a protective effect against MPP+-induced PC12 cell model damage,and the protective effect may be achieved by activating the Nrf2-antioxidant response element pathway.