The pulmonary toxicity study of nano-silica particles on rats through dynamic inhalation / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the pulmonary toxicity of different concentrations of nano-silica (nano-SiO2) under continuous dynamic inhalation conditions in the rat.</p><p><b>METHODS</b>48 male Sprague-Dawley rats were randomly divided into four groups, including the dispersant control group (saline) and nano-SiO2 low-dose group (0.3%, w/v), the middle-dose group (1%) and the high-dose group (3%). Animals were sacrificed at 28 d after exposure under continuous dynamic inhalation conditions, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected. And following items were observed: body coefficient, BALF related items (leukocytes and classification, total protein content, LDH activity), lung tissue pathological changes (HE staining), and pulmonary fibrosis forming (collagen fiber VG staining).</p><p><b>RESULTS</b>Compared to the dispersant control group, there was no significant change on lung organ coefficient in Nano-SiO2 group (P < 0.05). The BALF total WBC count in 1% and 3% in nano-SiO2 groups showed higher value than the dispersant control group (P < 0.05). No obvious changes were found on total protein content and LDH activity in nano-SiO2 groups compared to the dispersant control group (P > 0.05). For differential WBC counts, lymphocyte count in BALF in nano-SiO2 groups was significantly decreased (P < 0.05), monocyte and macrophage counts were significantly increased (P < 0.05), but there was no difference on the proportion of neutrophils (P > 0.05). HE staining results showed that the obvious thickening of alveolar wall in nano-SiO2 groups, inflammatory cell infiltration also increased around the bronchial and vascular wall. Lung fibrosis VG staining showed no significant change of collagen fiber distribution.</p><p><b>CONCLUSION</b>Under our experimental conditions, the continuous dynamic inhalation of nano-SiO2 only caused the significant inflammation in rat lungs, pulmonary fibrosis phenomenon could not be observed significantly.</p>

Pulmonary toxicity in high-fat diet SD rats induced by intravenous injection of multi-walled carbon nanotubes / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the pulmonary toxicity of multi-walled carbon nanotubes (MWCNTs) in high-fat diet SD rats.</p><p><b>METHODS</b>One hundred forty male SD rats were randomly divided into 6 groups. The normal control group, high-fat diet model group, vehicle group, and group treated with low dose of MWCNTs consisted of 30 rats, respectively, which were divided in 3 subgroups (10 rats each subgroup), respectively. The groups treated with medium and high loses of MWCNTs consisted of 10 rats, respectively. All the animals were exposed to high-fat-diet except for the control group which was given with normal diet. Before intravenous exposure, the high-fat diet model group, vehicle group, and three MWCNTs treated groups were gavaged with 700 thousand U/kg Vit D3 for three days, then given with high-fat-diet. The vehicle group was exposed to normal saline containing 1% Tween 80 and the low exposure group was exposed to MWCNTs at the dose of 50 µg/kg by tail vein injection twice a week for 8, 12 or 16 weeks. Other tow exposure groups were exposed to MWCNTs at the doses of 100, and 200 µg/kg by tail vein injection twice a week, respectively for 16 weeks. The lungs were from the executed rats, the lung indexes were calculated, the pathological changes of lungs were examined under light microscope after HE staining. qRT-PCR assay was utilized to detect the expression levels of pro-inflammation cytokines IL-1β (IL-1β) and TNF-α mRNA in the lungs.</p><p><b>RESULTS</b>As compared with the vehicle group, the lung indexes in groups exposed to 100 and 200 µg/kg MWCNTs increased significantly (P < 0.05). It was found under light microscope that the MWCNTs were accumulated in lungs of three exposure groups in 16 weeks after exposure, including pneumorrhagia, alveolar walls thicken, fibrosis, and granulomas. As compared with the vehicle group, the levels of IL-1β mRNA in group exposed to 50 µg/kg MWCNTs for 12 weeks and the groups exposed to 50, 100 and 200 µg/kg MWCNTs for 16 weeks decreased significantly (P < 0.05). As compared with the vehicle group, the levels of TNF-α mRNA in the groups exposed to 50 µg/kg MWCNTs for 8 and 16 weeks increased significantly (P < 0.05), the level of TNF-α mRNA in the groups exposed to 50 µg/kg MWCNTs for 12 weeks decreased significantly (P < 0.05). As compared with the vehicle group, the level of TNF-α mRNA in the groups exposed to 200 µg/kg MWCNTs for 16 weeks reduced significantly (P < 0.05).</p><p><b>CONCLUSION</b>The MWCNTs accumulation and chronic inflammatory changes were found in the lungs of rats exposed to MWCNTs by tail vein injection.</p>

Effects of multi-walled carbon nano onions on platelet adhesion and experimental thrombogenesis in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effects of multi-walled carbon nano-onions (MWCNOs) on platelet adhesion and experimental thrombosis in rats.</p><p><b>METHODS</b>Experimental rats were randomly divided into sham operation group, solvent group, and MWCNO group, each including 6 ∼ 9 rats. An inverted fluorescence microscope and a flow chamber were used to observe the effects of 20 g/ml MWCNOs on platelet adhesion at shear rates of 500 s(-1) and 1000 s(-1); the experiment was repeated at least three times in each group. A rat model of carotid artery thrombosis was induced by 25% FeCl3, and the effects of 2 mg/kg MWCNOs on the blood flow and wet weight of thrombus per millimeter in the model were observed.</p><p><b>RESULTS</b>When the shear rate was 500 s(-1), the MWCNO group showed a significantly smaller number of adhering platelets than the solvent group (58.3 ± 16.1 platelets/0.01 mm(2) vs 190.1 ± 36.0 platelets/0.01 mm(2)), but the inhibitory effect of MWCNOs on platelet adhesion disappeared as the shear rate increased to 1000 s(-1). The wet weights of thrombus per millimeter at 0 h after injection of a solvent or MWCNOs via the caudal vein were 0.83 ± 0.12 mg/mm in the solvent group and 0.97 ± 0.11 mg/mm in the MWCNO group, and the wet weights of thrombus per millimeter at 12 h after injection were 0.89 ± 0.12 mg/mm in the solvent group and 1.01 ± 0.15 mg/mm in the MWCNO group, exhibiting no significant differences between the two groups (P > 0.05). There were also no significant differences between the two groups in terms of blood flow at 0 h and 12 h after injection (P > 0.05).</p><p><b>CONCLUSION</b>MWCNOs have inhibitory effect on platelet adhesion in vitro, but the injection of MWCNOs via the caudal vein has no effects on the blood flow and wet weight of thrombus per millimeter in experimental thrombosis in rats.</p>

Effects of multiwall carbon nano-onions on platelet aggregation and hemostatic function / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effects of multiwall carbon nano-onions (MWCNOs) on platelet aggregation and hemostatic function.</p><p><b>METHODS</b>The platelet aggregation was determined with Born's method at different concentration of MWCNOs (0, 0.2, 2.0, 20.0 microg/ml) in vitro. Twenty male SD rats were randomly divided into 4 groups which were exposed to 0, 2, 4 and 8 mg/kg MWCNOs, respectively. Then platelet count, platelet aggregation, activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), bleeding time (BT) and platelet count (PC) were measured at 12 h after receiving tail intravenous injection of MWCNOs. The effects of MWCNOs (4 mg/kg) on platelet aggregation and platelet count at different time points were observed.</p><p><b>RESULTS</b>In vitro, MWCNOs exhibited the potent inhibitory effects on rat platelet aggregation caused by ADP in a concentration-dependent manner. The platelet aggregation in the highest dosage of 20.0 microg/ml group was 50.0% +/- 6.9% which was significantly lower than that (73.2% +/- 4.3%) in control group (P<0.01). In vivo, the highest inhibitory was up to 20.4%, but there was no significant difference, as compared with control group. MWCNOs did not affect the APTT, PT, TT, BT and PC.</p><p><b>CONCLUSION</b>Under this experimental condition, MWCNOs might inhibit platelet aggregation but not affect hemostatic function.</p>

Oxidative damage of single-walled carbon nanotubes in striaturn and hippocampi of mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the oxidative damage of SWCNTs in striaturn and hippocampi of mice.</p><p><b>METHODS</b>Forty male ICR mice were divided into experiment group (12.5 mg/kg SWCNTs) and control group (saline containing 0.1% Tween80) randomly. Each group was subdivided into 1, 7, 14 and 28 days group, 5 mice in each subgroup, then treated with tail intravenous injection for 5 continuous days. The striatum and hippocampus were isolated on the ice bath and homogenized in saline. SOD, GSH-Px, and MDA in the supernatants were measured with xanthine oxidize, GSH consumption in enzymatic reaction and TBA methods.</p><p><b>RESULTS</b>After exposure to 12.5 mg/kg SWCNTs for 5 d, SOD activity in striaturn and hippocampi decreased on 1st day and reached the minimum on 7th day, then increased gradually. The SOD activity in the SWCNTs treatment groups on 7th day were significantly decreased when compared to control (P < 0.05). Comparison with control group, GSH-Px activity in striaturn obviously decreased on 7th day then increased on 14th day, the difference between 7th day and 14th day was significantly (P < 0.05). GHS-Px activity in the hippocampi in SWCNTs group on 7th day and 14th day was significantly lower than that in control group (P < 0.05), then increased to the level of control group on 28th day. MDA contents of striaturn and hippocampi in SWCNTs group reduced on 1st day, then gradually increased on 7th day and 14th day, then reduced, MDA contents on7th day and 14th day n SWCNTs group were significantly higher than that in control group (P < 0.05).</p><p><b>CONCLUSIONS</b>The results of present study indicated that SWCNTs could decrease antioxidase activity and increase the Lipid peroxide in striaturn and hippocampi of mice.</p>

Antiandrogenic effects of cypermethrin and beta-cypermethrin / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the antiandrogenic activities of cypermethrin and beta-cypermethrin in vitro and in vivo.</p><p><b>METHODS</b>Transcriptional activation assay based on MDA-kb2 cell was used to determine the antiandrogenic effect of cypermethrin and beta-cypermethrin in vitro. The cells were treated by 10(-8), 10(-7), 10(-6) and 10(-5) mol/L of cypermethrin and beta-cypermethrin with 1.0 nmol/L DHT at the same time. The effects of antagonism towards the androgenic receptor were studied. In in vivo assays, Hershberger assay was used to determine the antiandrogenic activities of cypermethrin and beta-cypermethrin. Six-week-old castrated male SD rats were administered by cypermethrin (7, 21 and 63 mg/kg) and beta-cypermethrin (6, 18 and 54 mg/kg). After 7-day treatments, all rats were euthanized and androgen-responsive tissues were excised and weighed respectively.</p><p><b>RESULTS</b>The in vitro experiments showed that 10(-6) and 10(-5) mol/L cypermethrin could inhibit significantly the antagonism activity towards the androgenic receptor of DHT. In in vivo tests, the weight of seminal vesicle, ventral prostate, dorsolateral prostate and preputial glands in the 63 mg/kg cypermethrin [(52.8 +/- 7.1), (42.4 +/- 8.9), (36.6 +/- 4.5) and (43.4 +/- 11.1) mg] decreased significantly compared with those in the control group. In 21 mg/kg cypermethrin treated group only the weights of ventral prostate and dorsolateral prostate decreased significantly, and in 7 mg/kg cypermethrin only the weight of dorsolateral prostate decreased (P < 0.05). For beta-cypermethrin, any antiandrogen effect in in vivo and in vitro experiments was not found in all the groups.</p><p><b>CONCLUSION</b>Cypermethrin is a moderate antiandrogen that elicits antiandrogenic effects at least partly by antagonizing AR and beta-cypermethrin is not an antiandrogen in our experiments.</p>

Study of toxicity to rats induced by nanosized SiO2 and standard SiO2 / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the pulmonary toxicity to rats induced by the nanosized SiO(2) or the standard SiO(2).</p><p><b>METHODS</b>Seventy-two male SD rats were divided into three groups: the nanosized SiO(2) group, the standard SiO(2) group and the control group. 24 rats each group. The nanosized SiO(2) group and the standard SiO(2) group were instilled intratracheally with 0.5 ml suspension of 0.6 mg/ml nanosized SiO(2) or standard SiO(2) respectively while the control group was instilled with 0.5 ml physiological saline. On the 3rd, 7th, 14th, and 28th day after exposure, six rats were sacrificed at each time point and the total white cells counts and total protein in BALF and the histopathological changes were observed. The pulmonary toxicities of the two SiO(2) dusts were compared.</p><p><b>RESULTS</b>Nanosized SiO(2) caused significant increase at 3rd, 7th, 14th day after the exposure [(16.0 +/- 6.0) x 10(6), (11.1 +/- 4.0) x 10(6), (12.2 +/- 4.6) x 10(6)] compared with saline (P < 0.05 or P < 0.01) in the total numbers of white cells and on the 3rd after the exposure compared with standard SiO(2) [(5.7 +/- 3.7) x 10(6), P < 0.01]. Meanwhile, Nanosized SiO(2) significantly increased the total protein on the 14th, 28th day after the exposure (0.41 +/- 0.14, 0.41 +/- 0.19 g/L) compared with saline or standard SiO(2) and nanosized SiO(2) on the 3rd, 7th day after the exposure (P < 0.05 or P < 0.01). Nanosized SiO(2)-treated rats showed marked white cell infiltration in alveolar space or around brondum the blood vessel. Standard SiO(2) caused similar but less severe responses compared with nanosized SiO(2). Van Gieson's-stained sections showed no significant fibrosis in these dust-exposed rats at 28th day after the exposure.</p><p><b>CONCLUSION</b>Nanosized SiO(2) can cause severer and longer pulmonary toxicity in rats than standard SiO(2). The pulmonary particle load threshold of nanosized SiO(2) may be lower than that of standard SiO(2).</p>

Human pregnane X receptor-mediated transcriptional regulation of cytochrome P450 3A4 by some phytochemicals / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To test the effect on human pregnane X receptor (hPXR)-mediated transcription regulation of CYP3A4 by five selected phytochemicals.</p><p><b>METHODS</b>Transient cotransfection reporter gene assays in HepG(2) cells were performed with the hPXR expression plasmid and the reporter gene plasmid which contains XRE in the promoter of CYP3A4 linked to luciferase.</p><p><b>RESULTS</b>In the dose-effect study, soybean isoflavone, luteolin and curcumin induced the CYP3A4 transcription via PXR in an evident dose-dependent manner, but isorhamnetin and rutin did not. The inducibility of soybean isoflavone, luteolin and curcumin was also increased in concentrations between 1 micromol/L and 50 micromol/L, 24 h after induction, 50 micromol/L soybean isoflavone, luteolin and curcumin exhibited a 5.46-fold, 2.87-fold, and 2.07-fold increase respectively, compared with 0.1% DMSO treated cells. In the time-effect study, 10 micromol/L and 50 micromol/L soybean isoflavone, luteolin and curcumin induced CYP3A4 transcription between 12 h and 48 h, the strongest induction appeared in 48 h. 48 h after induction, 50 micromol/L soybean isoflavone, luteolin and curcumin exhibited a 6.72-fold, 3.24-fold, and 2.13-fold increase respectively, compared with 0.1% DMSO treated cells.</p><p><b>CONCLUSION</b>Three phytochemicals, i.e. soybean isoflavone, luteolin and curcumin stimulate the PXR-mediated transcription of CYP3A4. Isorhamnetin and rutin have no effect on the CYP3A4 transcription via PXR.</p>

Kaempferol activates human steroid and xenobiotic receptor-mediated cytochrome P450 3A4 transcription / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate whether kaempferol stimulates pregnane X receptor (PXR)-mediated transcription of CYP3A4.</p><p><b>METHODS</b>Transient cotransfection reporter gene assay was performed with PXR expression plasmid and a reporter plasmid containing the XREs in the CYP3A4 gene promoter in HepG(2)cells.</p><p><b>RESULTS</b>Kaempferol activated PXR-mediated transcription of CYP3A4 in a dose, time-dependent manner. In the dose-response study, kaempferol exposure at concentrations of 1.0 x 10(-3), 1.0 x 10(-2), 0.1, 1.0 and 10.0 mol/L for 24 h increased CYP3A4 transcription by (1.31+/-0.27), (1.45+/-0.36), (1.96+/-0.50), (2.90+/-1.07) and (7.93+/-0.75) fold, respectively compared with 0.1% DMSO (P<0.05). The results from time-course study showed that after 48 h exposure 1.0 and 10.0 mol/L of kaempferol enhanced the transcription of CYP3A4 by (3.73+/-1.21) fold and (8.42+/-1.47) fold, respectively.</p><p><b>CONCLUSION</b>Kaempferol may be a human CYP3A4 gene inducer through PXR, and may affect the metabolism of a large number of substrates of CYP3A4 simultaneously taken.</p>

Effects of kaempferol and quercetin on cytochrome 450 activities in primarily cultured rat hepatocytes / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To observe the effects of kaempferol and quercetin on the activity of cytochrome P450 in rat hepatocytes.</p><p><b>METHODS</b>Primarily cultured rat hepatocytes were exposed to kaempferol or quercetin in concentrations of 0.1, 1, 10 micromol/L for 12 h, 24 h and 48 h. Hepatocytes CYP isoemzymes-erythromycin N-demethylase (ERND) and aminopyrine N-demethylase (ADM) activities were determined by Nash methods. Erythromycin (10 micromol/L) was used as positive control and DMSO(0.1%) as solvent control.</p><p><b>RESULTS</b>Kaempferol and quercetin inhibited ENRD activity in a dose-and time-dependent manner. In dose-response study, the ENRD activities in kaempferol (0.1,1 and 10 micromol/L) treated groups were (0.088+/-0.008), (0.074+/-0.006) and (0.041+/-0.003)micromol/(mg.min(-1)), respectively. ENRD activity in quercetin treated groups at the same concentrations were (0.082+/-0.007), (0.063+/-0.007) and (0.034+/-0.005) micromol/(mg.min(-1)), respectively. In time-courses study, the ENRD activity exposed to 10 micromol/L kaempferol or quercetin for 12 h and 48 h were (0.053+/-0.006) and (0.037+/-0.007) micromol/(mg.min(-1)), or (0.067+/-0.005) and (0.032+/-0.004) micromol/(mg.min(-1)). ADM activity was inhibited only by kaempferol in 10 mol/L at 24 h, but was not significantly altered by quercetin at any concentration tested.</p><p><b>CONCLUSION</b>In the present condition, kaempferol and quercetin act as potential CYP3A4 inhibitors as they can significantly inhibit ENRD in primarily cultured rat hepatocytes.</p>

Effect of kaempferol on the pharmacokinetics of nifedipine in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effect of kaempferol on the pharmacokinetics of nifedipine (NFP) in rats.</p><p><b>METHODS</b>Twenty male SD rats, weighing 220-260 g, were distributed randomly into 4 groups. The animals were fasted, but allowed free access to water for 12 h before the administration of drugs. NFP dissolved in corn oil was administered via gastric intubation to the rats in control group at a dose of 10 mg/kg. Kaempferol was administered orally to the other three groups with dose of 5, 10, 15 mg/kg, respectively, followed by oral administration of NFP 10 mg/kg. Blood samples were collected through tail vein in heparinized plastic microcentrifuge tubes before and after drug administration. The plasma concentration of NFP was monitored with reversed phase high-performance liquid chromatography (RP-HPLC). Nimodipine was used as the internal standard. Statistical data evaluation was performed with Student's t-test and one-way analysis of variances.</p><p><b>RESULTS</b>The maximal plasma concentration (C(max)) of the three treated groups were 0.51, 0.70 and 0.81 microg/ml, respectively. The area under the concentration-time curve (AUC(0-8)) were 1.81, 2.83 and 3.63 microg/(h.ml(-1)), respectively. The C(max), AUC(0-8) and the mean retention time (MRT(0-8)) of NFP were significantly increased by simultaneous oral treatment with kaempferol (P<0.01). On the other hand, there were no significant differences in the mean peak value time in plasma (T(max)) and the elimination half-life (t1/2(ke)) between the control and the treated groups.</p><p><b>CONCLUSION</b>The concomitant oral use of kaempferol with NFP may influence the pharmacokinetic parameters of NFP in rats, which suggests that kaempferol might reduce the first-pass metabolism of NFP.</p>

Effects of phytoestrogens on gap junctional intercellular communication / 中华预防医学杂志

<p><b>OBJECTIVE</b>To observe effects of phytoestrogens quercetin (QC), Genistein (GEN), coumestrol (COM), and enterolactone (ENL) on gap junctional intercellular communication (GJIC) in HaCaT cells.</p><p><b>METHODS</b>HaCaT cells were exposed to QC, GEN, COM, and ENL at 0.1, 1.0, 10.0 and 100.0 micromol/L for 24 hours. The effects of phytoestrogens on GJIC were determined by fluorescence redistribution after photobleaching (FRAP) technique of using a laser scanning confocal microscope (LSCM).</p><p><b>RESULTS</b>QC did not affect the GJIC at 0.1-10.0 micromol/L, whereas, GEN, COM, and ENL exhibited inhibition on the GJIC in some extent at 0.1-10.0 micromol/L without showing significant cytotoxicity. The ratio of fluorescence recovery were between 31.77% to 37.06%, which were significantly decreased compared the vehicle control (44.74%).</p><p><b>CONCLUSION</b>The phytoestrogens GEN, COM, and ENL, but not QC, could inhibit the GJIC function in HaCaT cells at concentrations could be reached in human serum in some instance, indicating they could, under certain conditions, be cancer promoters. Therefore, it should be prudent to use these chemicals as pharmaceuticals or dietary supplements.</p>

The antiandrogenic effect of dimethachlon and its mechanism / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To evaluate the antiandrogenic effect of heterocyclic fungicide dimethachlon and its mechanism.</p><p><b>METHODS</b>A combination of in vivo and in vitro assays was selected. Hershberger assay was used to determine the antiandrogenic potential of dimethachlon in vivo. Six-week-old castrated male SD rats were administrated once daily for 7 days with testosterone propionate (TP, 100 micro g/d, sc) plus gavage doses of dimethachlon (50, 100 or 200 mg x kg(-1) x d(-1)), or procymidone (150 or 300 mg x kg(-1) x d(-1), positive control), or iprodione (100 mg x kg(-1) x d(-1), positive control), or flutamide (50 mg x kg(-1) x d(-1), positive control). Transcriptional activation assay in vitro was employed to determine the mechanism of antiandrogenic activity of dimethachlon. Human hepatoma liver cells HepG2 were transiently cotransfected with human androgen receptor (AR) expression plasmid and AR-dependent luciferase report plasmid. Transfected cells were exposed to various concentrations of dimethachlon or flutamide with or without dihydrotestosterone to induce the expression of luciferase gene.</p><p><b>RESULTS</b>In Hershberger assay, dimethachlon, as well as other known antiandrogens, caused decrease in weight of androgen dependent organs or tissues. In 200 mg/kg group, the weight of seminal vesicle, ventral prostate, dorsolateral prostate, Cowper's gland, and levator ani plus bulbocavernosus muscles decreased by 57.8%, 44.8%, 43.9%, 30.1%, and 34.1% respectively, but did not decrease in the vehicle control group. The order of their antiandrogenic potencies was: flutamide > procymidone > dimethachlon > iprodione. In transcriptional activation assay, dimethachlon could inhibit dihydrotestosterone-dependent AR activity in transfected HepG2 cells in dose-effect relationship. The inhibiting potency of dimethachlon was about 1/100 of that of flutamide.</p><p><b>CONCLUSION</b>Dimethachlon has antiandrogenic effect, and acts as an AR antagonist. Its antiandrogenic potency is lower than flutamide and procymidone, but higher than iprodione.</p>

Study on the mechanism of male reproductive toxicity of metadoxine in mice and rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the mechanism of male reproductive toxicity of metadoxine (MTDX) on mice and rats.</p><p><b>METHODS</b>Mouse multiple endpoints assay and Hershberger assay were employed to evaluate the potential estrogenic and/or antiandrogenic effects of MTDX. In mouse multiple endpoints assay, MTDX (0, 640, 1500 and 4000 mg/kg, respectively) were administered once daily p.o. for 5 days in sexually matured and ovariectomied female NIH mice. Five endpoints evaluated as markers of estrogenicity included the ratio of uterine weight to body weight, incidence and extent of uterine fluid imbibition (hydrometra), vaginal epithelial cornification during estrous cycle (estrinization) and thickness of uterine epithelial cell and stroma cell. In Hershberger assay, MTDX (0, 600 and 1500 mg/kg, respectively) was administered once daily p.o. for 10 days to castrated male SD rats with or without testosterone propionate (TP, 12.5 mg/kg, i.p. for 10 days) substitution. Relative weight of androgen dependent issues was measured.</p><p><b>RESULTS</b>In mouse multiple endpoints assay, ratio of uterine weight to body weight was 1.33, 1.38 and 1.31 x 10(-4) in MTDX 640, 1500 and 4000 mg/kg groups, respectively, without significant difference from that in control group (1.22 x 10(-4)). Thickness of uterine uterine epithelial cell (0.90 and 1.03 microm) and stroma cell (3.38 and 3.25 microm) in MTDX 1500 and 4000 mg/kg groups was not significantly different from the control group (0.85 microm and 2.77 microm, respectively). In Hershberger assay, relative weight of prostate plus seminal vesicle, levator ani muscle and bulbocavernous muscle was 1.13, 0.17 and 0.42, respectively, in the 1500 mg/kg group, significantly decreased as compared with those in the control group (1.46, 0.24 and 0.70, respectively) (P < 0.01). Relative weight of prostate plus seminal vesicle (1.29) in the MTDX 600 mg/kg group reduced slightly, with statistical significance (P < 0.05), as compared with that in the control group (1.46).</p><p><b>CONCLUSIONS</b>In the present study, MTDX did not exhibit any estrogenic effect in mice in vivo. However, it had antiandrogenic activity in castrated male SD rats, indicating that its antiandrogenic effect may be involved in it's male reproductive toxicity.</p>

Study on the transcriptional modulation of cytochrome P450 3A4 expression by zearalenone / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study whether zearalenone (ZEA), a fungal estrogen, can transcriptionally up-regulate the expression of cytochrome 450 3A4 (CYP3A4) transcription by activating human steroid hormone and xenobiotic receptor (SXR).</p><p><b>METHOD</b>Transient cotransfection reporter gene assays were performed with human SXR expression plasmid and a reporter plasmid containing the SXR in the CYP3A4 gene promoter in HepG(2) cells.</p><p><b>RESULTS</b>The transcriptional induction of CYP3A4 by ZEA with a dose, time-dependent manner. ZEA at the concentrations of 0.01, 0.10, 1.00 and 10.00 micromol/L, respectively, could induce CYP3A4 with (1.50 +/- 0.21), (1.66 +/- 0.27), (3.04 +/- 0.82) and (3.96 +/- 1.16) folds, as compared with 0.1% DMSO. Results from a time-dependent study show that 1.00 and 10.00 micromol/L of ZEA for 12 to 48 hours could enhance the transcription of CYP3A4 with (3.69 +/- 1.34) and (5.18 +/- 1.50) folds, and 10.00 micromol/L of ZEA for 48 hours could induce the CYP3A4 gene expression (5.18 +/- 1.50) folds, as compared with 0.1% DMSO by activating human SXR.</p><p><b>CONCLUSION</b>ZEA could induce the expression of the CYP3A4 gene transcription through activating SXR, possibly by affecting the other substrates of the CYP3A4, especially affecting the metabolism of drugs in the body.</p>

Assessment of the estrogenicity of endosulfan and other chemicals with the in vitro proliferation of human breast cancer cell / 浙江大学学报·医学版

OBJECTIVE: To develop a rapid screening method for xenoestrogens and to screen the estrogenicity of some environmental chemicals. METHODS: The E-SCREEN test was developed based on proliferation of human breast cancer cells (MCF-7), and the estrogenicity of diethylstilbestrol, 4-hydrotamoxifen and endosulfan was assessed. RESULTS: The E-SCREEN detected estradiol at very low concentration as 1x10(-13) mol/L. It was found that diethylstilbestrol was a full agonist of estrogen receptor, endosulfan was a partial agonist, while 4 hydrotamoxifen lacked estrogenic effects at this assay. CONCLUSION: The E-SCREEN test is sensitive, rapid, easy to perform and, therefore, suitable for large scale screening for estrogenicity of environmental chemicals.

Immunomodulatory effects of polysaccharide of Cistanche Deserticola Y C Ma / 浙江大学学报·医学版

OBJECTIVE: To study the immunomodulatory effects of the polysaccharide Cistanche Deserticola Y C Ma (CDPS) and its mechanism. METHODS: The immunomodulatory function of CDPS was studied in vitro by observing the proliferation of murine thymus lymphocytes, which was measured with MTT method. The effects of CDPS on cell cycle and thymus intracellular calcium delivering were studied with FACScan flow cytometer. RESULTS: The inhibition function of ISO and DEX and high concentration of TNFgamma on lymphocyte proliferation was decreased with CDPS at higher concentration. It could stimulate the division of thymus lymphocyte and promote thymus intracellular calcium delivering. CONCLUSION: The enhancing effect of CDPS on murine thymus lymphocyte proliferation is related to its promotion on thymus intracellular calcium delivering.