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Objective To evaluate the protective effect of pterostilbene against ultraviolet B (UVB)-induced acute damage in HaCaT cells,and to explore related mechanisms.Methods The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazo1ium (MTS) assay and flow cytometry were performed to estimate the proliferative activity and the apoptosis and necrosis rate of HaCaT cells treated with different concentrations of pterostilbene respectively,so as to screen the non-toxic concentration of pterostilbene.HaCaT cells were randomly divided into several groups:normal control group receiving no treatment,UVB group irradiated with 57 mJ/cm2 UVB,3 pterostilbene groups treated with 2.44,4.88 and 9.75 μmol/L pterostilbene respectively for 24 hours,3 pterostilbene + UVB groups treated with 2.44,4.88 and 9.75 μmol/L pterostilbene respectively for 24 hours followed by UVB radiation.Western blot analysis was conducted to detect changes of the transcription factor NF-E2-related factor 2 (Nrf2) expression in cell nuclei and cytoplasm before and after the treatment with pterostilbene and UVB,quantitative PCR to determine the mRNA expression of catalase and superoxide dismutase in the HaCaT cells,and enzyme-linked immunosorbent assay (ELISA) to evaluate the activity of catalase and superoxide dismutase.Results MTS assay and flow cytometry showed that 2.44,4.88 and 9.75 μmol/L pterostilbene had non-toxic effect on HaCaT cells.The protein expression of Nrf2 in the nuclei and cytoplasm in the normal control group was 1.03 ± 0.08 and 1.04 ± 0.11 respectively.Compared with the normal control group,the protein expression of Nrf2 in the nuclei and cytoplasm experienced no significant changes in the 2.44-,4.88-and 9.75-μmol/L pterostilbene groups,and the UVB group showed similar protein expression of Nrf2 in the cytoplasm,but significantly increased protein expression of Nrf2 in the nuclei (1.77 ± 0.08,q =17.24,P ＜ 0.01).Compared with the normal control group and UVB group,the 2.44-,4.88-and 9.75-μmol/L pterostilbene + UVB groups all showed significantly lower protein expression of Nrf2 in the cytoplasm (0.86 ± 0.10,0.87 ± 0.11 and 0.46 ± 0.11 respectively,all P ＜ 0.05),but significantly higher protein expression of Nrf2 in the nuclei (2.38 ± 0.11,2.57 ± 0.11 and 2.07 ± 0.13,all P ＜ 0.01).As qPCR showed,UVB radiation could significantly inhibit the mRNA expression of CAT (P ＜ 0.05),but had no obvious effect on the mRNA expression of SOD (P ＞ 0.05).The mRNA expression of CAT and SOD experienced no significant changes in the 2.44-,4.88-and 9.75-μmol/L pterostilbene groups compared with the normal control group (P ＞ 0.05).However,2.44,4.88 and 9.75 μmol/L pterostilbene could significantly reduce the inhibitory effect of UVB radiation on the mRNA expression of CAT (P ＜ 0.05) and up-regulate the mRNA expression of SOD in the pterostilbene + UVB groups (P ＜ 0.05).ELISA revealed that UVB radiation could inhibit the activity of CAT and SOD in the HaCaT cells (both P ＜ 0.001),while 2.44,4.88 and 9.75 μmol/L pterostilbene could reduce the inhibitory effect of UVB radiation on the activity of CAT and SOD (all P ＜ 0.05).However,the activity of CAT and SOD were still lower in the 2.44-,4.88-and 9.75-μmol/L pterostilbene + UVB groups than in the normal control group (P ＜ 0.05).Conclusion Pterostilbene can prevent UVB-induced acute damage in HaCaT cells by activating the Nrf2 pathway and up-regulating the expression of the downstream antioxidant enzymes CAT and SOD.
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Objective To explore the effect of tea polyphenols on the growth of human papillomavirus 16 (HPV16) subgenes-immortalized human cervical epithelial cells (H8 cells).Methods Cultured H8 cells were divided into 5 groups to be treated with 0 (control group),6.25,12.5,25 and 50 mg/L tea polyphenols respectively for 24,36,and 48 hours,and then cell counting kit-8 (CCK8)assay was performed to detect cell proliferation.After 24 hours of incubation,flow cytometry was conducted to detect cell apoptosis and cell cycle,and fluorescence microscopy to observe the morphology of apoptotic cells.Results After incubation with tea polyphenols at different concentrations for 24,36 and 48 hours,the proliferation of H8 cells was inhibited,and 12.5 mg/L tea polyphenols could inhibit the relative growth rate of H8 cells in a time-dependent manner.Flow cytometry showed that there was a significant difference in cell apoptosis rate among the 6.25-,12.5-,25-,50-mg/L tea polyphenols groups and the control group (52.62％ ± 0.62％,52.22％ ± 0.72％,42.52％ ± 0.90％,45.96％ ± 2.11％,29.96％ ± 0.70％ respectively,F =272.0,P ＜ 0.05).Moreover,all the tea polyphenol groups showed significantly increased cell apoptosis rate compared with the control group (all P ＜ 0.05).Fluorescence microscopy showed karyopyknosis,nuclear fragmentation and other typical apoptotic morphological changes in H8 cells in tea polyphenols groups.There were significant differences in the percentage of cells in G1,G2 phase and cell proliferation index among the 5 groups (all P ＜ 0.05).Compared with the control group,the 6.25-,12.5-,25-mg/L tea polyphenols groups showed significantly increased percentage of cells in G1 phase (55.96％ ± 0.72％,54.12％ ± 3.20％,65.30％ ± 1.51％ respectively,all P ＜ 0.05),but significantly decreased percentage of cells in G2 phase (3.17 ± 1.82％,4.94 ± 1.46％,4.65 ± 4.26％ respectively,all P ＜ 0.05) and lower cell proliferation index(0.44 ± 0.01,0.46 ± 0.02,0.36 ± 0.01 respectively,all P ＜ 0.05).Conclusion Tea polyphenols can inhibit the proliferation of H8 cells,induce cell apoptosis,and block cell cycle progression.
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Objective To investigate the protective effect of lycium barbarum polysaccharide (LBP) on DNA damage of HSF cells induced by UV.Methods We established the model of UV induced photo damage in HSF cells.We detected the viability of HSF cells by using MTT colorimetry.The UV absorption spectrum of LBP was also measured by UV spectrophotometer.The level of ROS was detected by DCFH-DA fluorescent probe method.Comet assay was employed to evaluate the DNA strand breakage damage.Results When the concentration of LBP was less than or equal to 300μg/ml,there was no significant effect on the proliferation of HSF cells (P＞0.05).When the concentration was more than 300 μg/ml,it could inhibit the cell proliferative activities (P＜0.05).Compared to the UV groups,UV+LBP groups can respectively improve the cell proliferation activity (P＜0.05).The absorbance was slight range 280 from 400 nm.Compared with the UV group,the relative fluorescence intensity and the migration distance of UV+ LBP groups were significantly decreased (P＜0.05).Conclusions Lycium barbarum polysaccharide can effectively inhibit the proliferation activity and protect the breakage of DNA strand induced by UV,which is probably due to its action of removing free radicals.
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Objective To evaluate the scavenging effect of crude polysaccharides extracted from Lycium barbarum (LBP) on reactive oxygen species in ultraviolet radiation-induced HaCaT cells,and to explore its possible mechanism.Methods Cultured immortalized human keratiuocyte HaCaT cells were divided into 6 groups:blank control group receiving no treatment,LBP group treated with crude LBP alone,ultraviolet A (UVA) group treated with UVA radiation alone,ultraviolet B (UVB) group treated with UVB radiation alone,UVA + LBP group treated with crude LBP for 24 hours followed by UVA radiation,and UVB + LBP group treated with crude LBP for 24 hours followed by UVB radiation.MTT colorimetry was performed to evaluate the cellular proliferative activity,UV spectrophotometric method to measure the UVA and UVB absorption of crude LBP,dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe assay to detect the level of ROS,enzymatic-biochemical method to estimate the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px),as well as to detect the leakage of lactate dehydrogenase (LDH).Results Crude LBP at different concentrations of 0,100,200,300,400,500,600,1 500,2 000 mg/L had no obvious effects on the proliferative activity of HaCaT cells.Crude LBP had a high transmittance of ultraviolet rays at 280-400 nm.Compared with the blank control group,the UVA group and UVB group both showed significantly higher LDH leakage and ROS level,lower activities of SOD and GSH-Px (P ＜ 0.001 or 0.05).Pretreatment with crude LBP before the ultraviolet radiation could significantly increase the activities of SOD and GSH-Px,decrease the LDH leakage and ROS level in the UVA + LBP group and UVB + LBP group compared with the UVA group or UVB group (P ＜ 0.05).Conclusion Crude LBP have no effect of sunscreening agents,but can effectively scavenge ROS,decrease LDH leakage,inhibit ultraviolet radiation-induced photodamage in HaCaT cells,which may be associated with the enhancement of antioxidant enzyme activity.
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Objective To evaluate effects of tea polyphenols on the mRNA and nucleoprotein expression of Nrf2/Bach1 in human skin fibroblasts (HSFs).Methods Some HSFs were incubated with tea polyphenols at different concentrations of 0,2.5,5,10,20 and 40 mg/L for 24 hours.Methyl thiazolyl tetrazolium (MTT) assay was conducted to evaluate the proliferative activity of HSFs to screen the optimal concentration of tea polyphenols.Then,some other HSFs were treated with tea polyphenols at this optimal concentration for 24 hours.Real-time quantitative PCR (RT-qPCR) was performed to determine mRNA expression of Nrf2 and Bach1,Western blot analysis to measure nuclear expression of Nrf2 and Bach1 proteins,and immunofluorescence assay to determine the distribution of Nrf2 and Bach1 protein in the cell nucleus.Results MTT assay showed that 5 mg/L tea polyphenols had no obvious effects on the proliferation of HSFs,so 5 mg/L was chosen as the optimal concentration of tea polyphenols for subsequent experiments.HSFs cultured without tea polyphenols served as control group.After the treatment,the 5-mg/L tea polyphenol group showed significantly decreased mRNA and nuclear protein expression of Bach 1 (mRNA:0.629 ± 0.077 vs.0.940 ± 0.033,t =6.397,P ＜ 0.05;protein:1.424 ± 0.171 vs.16.966 ± 1.702,t =15.730,P ＜ 0.05),but significantly increased mRNA and nuclear protein expression of Nrf2 (mRNA:1.467 ± 0.076 vs.0.977 ± 0.091,t =7.133,P ＜ 0.05;protein:6.929 ± 0.121 vs.3.537 ± 0.126,t =33.636,P ＜ 0.05) compared with the control group.Immunofluorescence assay showed increased accumulation of Nrf2 protein,but decreased accumulation of Bach1 protein in the nucleus.Conclusion Tea polyphenols can promote the mRNA and nuclear protein expression as well as nuclear distribution of Nrf2,but suppress the mRNA and nuclear protein expression as well as nuclear distribution of Bach 1,finally exerting antioxidative effects.
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Objective To establish an animal model for immunological contact urticaria in mice.Methods A total of 60 BALB/c mice were randomly and equally divided into 5 groups:anti-dinitrophenol IgE monoclonal antibody (anti-DNP IgE) + 2,4-dinitrofluorobenzene (DNFB) group and anti-DNP IgE + trimellitic anhydride (TMA) group both injected with anti-DNP IgE via tail veins firstly,followed by topical treatment with DNFB and TMA respectively on the ears at 24 hours after the injection,DNFB group,TMA group and normal saline (NS) group all injected with NS via the tail vein firstly,followed by topical treatment with DNFB,TMA and NS on the ears 24 hours after the injection.In the following 14 days,mice were observed daily for the appearance of wheals and for scratching behavior.All the mice were sacrificed at the end of the study followed by determination of the percentage of degranulated mast cells and spleen index as well as observation of pathological changes.Results Wheals were observed in all the mice (12/12) in the anti-DNP IgE + DNFB group,some mice (8/12) in the anti-DNP IgE + TMA group,but not observed in any mice in the other 3 groups.Compared with the NS group,both the anti-DNP IgE + DNFB group and anti-DNP IgE + TMA group showed a significant increase in the percentage of degranulated mast cells (70.21％ ± 26.01％ and 54.25％ ± 39.57％ vs.14.45％ ±6.79％,F=14.41,P=0.000),spleen index (7.54 ± 1.56 and 7.87 ± 1.18 vs.5.37 ± 1.16,F=4.29,P=0.004) and scratching frequency ((31.58 ± 3.58)/h and (22.17 ± 3.81)/h vs.(2.00 ± 0.85)/h at 30 minutes,F =437.86,P ＜ 0.01).Conclusion A stable mouse model for immunological contact urticaria can be established quickly by sensitization with anti-DNP IgE and challenge with DNFB.
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Objective To investigate the role of regulatory T (Treg) / T helper type 17 (Th17) cells in the pathogenesis of chronic spontaneous urticaria (CSU).Methods Eighty-nine patients with CSU were enrolled in this study,including 48 in active stage and 41 in remission stage.Forty-eight health check-up examinees,who were collected from the community hospitals in Guangzhou city,served as the healthy controls.Fluorescence-based realtime quantitative PCR was performed to determine the expression of transcription factors FOXP3 and RORγt in PBMCs from these subjects.Results Compared with the patients with CSU in remission stage and healthy controls,the patients in active stage showed a significantly higher level of FOXP3 mRNA (0.57 ± 0.19 vs.0.11 ± 0.21 and 0.13 ± 0.23,both P ＜ 0.05),but a significantly lower level of RORγt mRNA (0.43 ± 0.39 vs.0.89 ± 0.40 and 0.87 ± 0.43,both P ＜ 0.05).Conclusions The expression of Treg cell regulator FOXP3 increases,while the expression of Th17 cell regulator RORγt decreases in patients with CSU,suggesting that the imbalance between Treg and Th17 cells induced by the interaction between FOXP3 and RORγt may be involved in the pathogenesis of CSU.
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Objective To determine the coagulation status as well as circulating levels of complement and inflammation markers in patients with chronic urticaria (CU) during acute attack and in remission,and to estimate the relationship of coagulant and anticoagulant factors as well as fibrinolytic markers with the development of chronic urticaira.Methods This study included 40 patients with CU (22 during acute attack and 18 in remission) and 40 healthy blood donors from the Guangzhou Blood Center.Venous blood samples were obtained from these subjects,and enzyme-linked immunosorbent assay (ELISA) was performed to measure the plasma levels of prothrombin fragrnent 1 +2 (F1 +2),tissue factor (TF),thrombomodulin (TM),high molecular weight kininogen (HMWK),tissue-type plasminogen activator (t-PA),C5a and serum levels of C3,C4,antistreptolysin O antibodies (ASO),rheumatoid factor (RF) and C-reactive protein (CRP).Erythrocyte sedimentation rate (ESR) was also determined in these patients.Comparisons of these parameters were carried out by using t test,and the correlation of these factors with CU was evaluated by using Spearman correlation coefficient.Results Compared with the healthy controls,the patients with CU showed significantly higher plasma levels of F1+2 and HMWK (both P ＜ 0.01),but lower levels of TF,TM and t-PA (all P ＜ 0.01).The plasma levels of F1 +2,HMWK,t-PA were significantly correlated with the symptom scores in patients with CU (r =0.81,P ＜ 0.01; r =-0.39,P ＜ 0.05; r =0.35,P ＜ 0.05).A significant increase was observed in the plasma concentration of F1 +2 in patients during acute attack compared with those in remission (P ＜ 0.01),whereas no significant differences were noted in the plasma levels of TF,TM,HMWK,t-PA,C5a,serum levels of C3,C4,ASO,RF and CRP or ESR between the two groups of patients (all P ＞ 0.05).Conclusions It seems that coagulation,anti-coagulation and fibrinolysis are all involved in the development of urticaria.There is an obvious difference in the plasma level of prothrombin F1 +2 between patients with CU during acute attack and in remission,suggesting that coagulation factors play a certain role in the initiation and progression of CU.
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Objective To study the influence of sunscreens with different efficacy on delayed type hypersensitivity (DTH) and their immunoprotective effect in mice.Methods A cohort of mice were randomly divided into 5 groups with 10 mice in each group:group 1 as the positive control without irradiation,group 2 receiving solar-simulated radiation (SSR) only,group 3 receiving SSR and protected by sunscreen l with sun protection factor 15(SPF15)and persistent pigment darkening(PPD)12,group 4 receiving SSR and protected by sunscreen 2 with SPF 50 and PPD 28,and group 5 as the negative contml receiving SSR only.SSR was carried out on the back of mice with the UVA dose being 1.4 J/cm2 and UVB dose being 100 mJ/cm2 for 10 days.After a 5-day irradiation,the groups 1 to 4 were immunized by intraperitoneal injection with 100 μl(107 cells/ml) of Candida albicans suspension.On the 10th day both sides of the posterior foot pad were measured;then the foot pads were injected with additional 50 μl of the Candida albicans suspension.Twenty-four hours after the injection,the thickness of each foot pad was measured,and immunosuppression rate was calculated.Finally,the mice were sacrificed and skin samples were obtained from the back of these mice followed by the examination of CDla, CD80 and CD86 expression by Western blot.Resets The thickness of edema in foot pads was 0.41±0.38 mm,0.21±0.23 mm and 0.30 ± 0.25 mm in group 1,3 and 4,respectively,significantly higher than in group 5 and 2(0.04±0.03 mm,0.14±0.12 mm,respectively,all P0.05).Significant differences were observed in the immunosuppression rate between group 2,3 and 4(73.0%±11.3%,54.1%±6.4%,29.7%±7.5%,respectively,all P0.05).Conclusions The exposure to sub-erythema dose of UV can induce DTH,and sunscreens have an immunoprotective effect in this process.Epidermal Langerhans cells are not essential for UV-induced immunosuppression.
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Objective To evaluate the relationship of clinical symptom to plasmic levels of D-dimer, activated factorⅦ (FⅦa) and tissue factor pathway inhibitor (TFPI)/X a in patients with urticaria. Methods A total of 27 patients with chronic urticaria (CU), 27 patients with acute urticaria (AU) and 26 normal human controls were included in this study. Symptom score was determined and disease course was surveyed in these patients. ELISA was used to detect the plasma levels of D-dimer, FⅦa and (TFPI)/Xa in patients and controls. The relation of clinical symptom and disease course to plasma levels of these parameters was assessed. Results In patients with AU and normal controls, the plasma level of D-dimer was 450.57± 242.13 ng/mL and 266.81±40.68 ng/mL, respectively, the level of FⅦa, 2.23± 0.74 ng/mL and 5.23±1.35 ng/mL, respectively, and the level of TFPI/Xa 0.87±0.13 nmol/L and 0.88 ~ 0.12 nmol/L, respectively. There was a significant difference in the level of both D-dimer and FⅦa (both P < 0.01 ), whereas no differ-ence was observed in that of TFPI/X a (P > 0.05) between patients with AU and normal controls. In addi-tion, increased level of D-dimer and decreased level of FⅦa were noticed in patients with CU compared with those in normal controls (593.80±294.04 ng/mL vs 266.81±40.68 ng/mL, 3.98±0.35 ng/mL vs 5.23± 1.35 ng/mL, both P < 0.01 ), but there was no significant difference in the plasma level of TFPI/Xa (0.87± 0.16 nmol/L vs 0.88±0.12 nmol/L, P > 0.05). Significant difference was observed in the plasma level of D-dimer and FⅦa between patients with AU and CU (450.57±242.13 ng/mL vs 593.80 ±294.04 ng/mL, P < 0.05; 2.23± 0.74 ng/mL vs 3.98± 0.35 ng/mL, P<0.01 ). The plasma level of D-dimer positively corre-lated to the symptom score of patients with CU and those with AU (r= 0.68, P< 0.01; r= 0.82, P< 0.01),but was independent of discase course (P> 0.05). Neither the level of FⅦa nor that of TFPI/Xa correlated to symptom score or disease course of patients (all P > 0.05). Conclusions There is an overactivation of coagulation cascade, consumption of blood coagulation factors and secondary fibrinolysis in patients with urticaria, suggesting that plasma D-dimer and FⅦa may be associated with the clinical symptoms of urticaria.