Effect of deltamethrin on production of reactive oxygen species in PC12 cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effect of deltamethrin (DM) on production of reactive oxygen species (ROS) of rat pheochromocytoma (PC12) cells and its mechanism.</p><p><b>METHODS</b>PC12 cells were treated with various dose of DM (0, 10 or 100 micromol/L) for 1, 6 or 12 h respectively. Furthermore, PC12 cells were treated with various dose of DM (0, 10 or 100 micromol/L) for 24 or 48 h, respectively. PC12 cells were pre-incubated with 10 mmol/L N-acetyl-L-cysteine (NAC) for 2 h, or with 500 micromol/L DL-Buthionine-[S, R]-Sulfoximine (BSO) for 16 h, or with 40 micromol/L tertiary butylhydroquinone (tBHQ) for 16 h, prior to exposure to DM and then with 10 micromol/L DM for 6 h. After treatment, ROS production in PC12 cells were measured by a molecular probe, 2', 7'-dichlorofluorescein diacetate (DCFH-DA).</p><p><b>RESULTS</b>DM induced a dose-time dependent increase in ROS production (indicated by DCF fluorescence intensity). 10 micromol/L DM treatment for 6 h enhanced DCF fluorescence intensity that reached approximately 2.24 times of values of control group. Furthermore, a pretreatment with NAC, BSO or tBHQ significantly reduced the DM-enhanced DCF fluorescence intensity that reached approximately 22%, 62% or 38% of values of DM treatment, respectively (P < 0.05), indicating that all these pretreatments attenuate ROS production.</p><p><b>CONCLUSION</b>The in vitro studies demonstrate that DM could enhance ROS production, and may be the influential factor for the decreased mercapto level and antioxidative function.</p>

Protective effect of melatonin on oxidative damage by deltamethrin in rat brain / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the potential protective effect of melatonin on the oxidative damage induced by deltamethrin in cerebral cortex, hippocampus and cerebellum of rats.</p><p><b>METHODS</b>35 male wistar rats were randomly divided into five groups(seven rats per group): olive oil control, deltamethrin-treated (12.5 mg/kg), melatonin(25.0 mg/kg) and deltamethrin plus melatonin (25.0 mg/kg , 2.5 mg/kg respectively) group. Levels of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione (GSH) in cerebral cortex, hippocampus and cerebellum were determined after 5 days of DM treatments.</p><p><b>RESULTS</b>MDA content in cerebral cortex, hippocampus and cerebellum tissue of the DM-treated rats were significantly higher than those in control group, and compared with DM-treated group, MDA content in those tissue of MT + DM-treated group have significantly decreased after 5 days of DM exposure (P < 0.05). Activities of GSH-Px in DM-treated group were significantly lower than those in control group, and those in the MT + DM group were significantly higher than DM group(P < 0.05).</p><p><b>CONCLUSION</b>DM can induce the oxidative damage in rat brain and melatonin has protective effects on deltamethrin-induced oxidative damage in hippocampus, cerebral cortex and cerebellum of rats.</p>

Effects of deltamethrin on gene expression of some antioxidase, gamma glutamylcysteine synthetase and NFE2 related factor 2 (Nrf2) in brain tissue / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of deltamethrin (DM) on the mRNA expression of copper-zinc dependent SOD (CuZn-SOD), glutathione reductase (GR) and gamma glutamylcysteine synthetase (gamma-GCS) light subunit (GCSl), as well as on expression of both mRNA and protein of gamma-GCS heavy subunit (GCSh) and NFE2 related factor 2 (Nrf2) in cerebral cortex and hippocampus of rats.</p><p><b>METHODS</b>Eighteen Wistar male rats were randomizedly divided into three groups, six for each group. The low dosage and high dosage DM treated groups were administrated intraperitoneally with DM (the daily dosage was 3.125, 12.500 mg/kg BWT respectively) for five consecutive days while the control group was administered intraperitoneally with olive oil. The relative amount of mRNA expression of these genes was measured by the method of reverse transcription polymerase chain reaction (RT-PCR) (n = 6). The protein level was detected by the method of immunohistochemistry and image analysis system (n = 4).</p><p><b>RESULTS</b>There was no change in mRNA expression level of CuZn-SOD, GR, GCSh and Nrf2 gene in both cerebral cortex and hippocampus tissue in rats administrated with DM. However, the mRNA level of GCSl gene in cerebral cortex of high dosage group as well as in both cerebral cortex and hippocampus of the low dosage group was significantly lower than that in corresponding tissue in the control group, and was decreased to 71.1%, 63.6% and 75.2% of mRNA level of corresponding tissue in the control group (P < 0.01). There was no obvious effect on protein level of both GCSh and Nrf2 in CA1, CA2, CA3 and dentate gyrus (DG) of hippocampus as well as on that in cerebral cortex in rats treated with DM.</p><p><b>CONCLUSION</b>Under the experimental conditions, there is no obvious effect in the mRNA expression level of CuZn-SOD, GR gene, as well as on expression of both mRNA and protein of Nrf2 gene in both cerebral cortex and hippocampus tissue in rats administered with DM. DM depresses the mRNA expression of GCSl gene, but does not affect the mRNA expression of GCSh gene.</p>

Effects of deltamethrin on the apoptosis and the expression of caspase-3 in rat neural cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of deltamethrin on the apoptotic rate and the expression of caspase-3 in rat neural cells.</p><p><b>METHODS</b>Male Wistar rats were randomly divided into 5 groups: control, 5 h, 24 h, 48 h and 5 d exposed groups. Apoptotic rate and the expression of caspase-3 were measured by FACS420 Flow Cytometer; Ac-DEVD-pNa was used as a substrate to detect the activity of caspase-3.</p><p><b>RESULTS</b>Apoptotic rates in 24 h, 48 h and 5 d exposed groups in hippocampus and cerebral cortex [hippocampus: (8.45 +/- 1.02)%, (9.44 +/- 1.14)%, (7.58 +/- 0.75)%; cerebral cortex: (7.90 +/- 0.49)%, (8.01 +/- 0.87)%, (7.97 +/- 0.41)% respectively] were higher than those in the control [hippocampus: (2.97 +/- 0.36)%; cerebral cortex: (3.50 +/- 0.48)%] (P < 0.01); the activity of caspase-3 in 5 h, 24 h and 48 h exposed groups (A(405) nm in hippocampus: 0.389 +/- 0.038, 0.472 +/- 0.041, 0.295 +/- 0.049; A(405) nm in cerebral cortex: 0.321 +/- 0.068, 0.429 +/- 0.077, 0.344 +/- 0.047) and 5 d group of hippocampus (0.246 +/- 0.065) were all higher than those of the control (hippocampus: 0.184 +/- 0.054; cerebral cortex: 0.198 +/- 0.049) (P < 0.05, P < 0.01); the expression of caspase-3 in 5 h, 24 h and 48 h exposed groups increased apparently while 5 d group did not.</p><p><b>CONCLUSION</b>Exposure to high dose of deltamethrin would affect the apoptosis, the activity and expression of caspase-3 in rat neural cells. The increase in caspase-3 activity and expression occurred before the rising of neuronal apoptotic rate may be the upstream event of apoptosis.</p>