Endogenous abscisic acid is involved in methyl jasmonate-induced reactive oxygen species and nitric oxide production but not in cytosolic alkalization in Arabidopsis guard cells

We recently demonstrated that endogenous abscisic acid (ABA) is involved in methyl jasmonate (MeJA)-induced stomatal closure in Arabidopsis thaliana. In this study, we investigated whether endogenous ABA is involved in MeJA-induced reactive oxygen species (ROS) and nitric oxide (NO) production and cytosolic alkalization in guard cells using an ABA-deficient Arabidopsis mutant, aba2-2, and an inhibitor of ABA biosynthesis, fluridon (FLU). The aba2-2 mutation impaired MeJA-induced ROS and NO production. FLU inhibited MeJA-induced ROS production in wild-type guard cells. Pretreatment with 0.1 μM ABA, which does not induce stomatal closure in the wild type, complemented the insensitivity to MeJA of the aba2-2 mutant. However, MeJA induced cytosolic alkalization in both wild-type and aba2-2 guard cells. These results suggest that endogenous ABA is involved in MeJA-induced ROS and NO production but not in MeJA-induced cytosolic alkalization in Arabidopsis guard cells.     

Amelioration of cognitive impairment and neurodegeneration by catechin hydrate in rat model of streptozotocin-induced experimental dementia of Alzheimer’s type

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder resulting in cognitive decline and enhancement of oxidative loads in the brain. Flavonoids have been considered to exert human health benefits by anti-oxidant and anti-inflammatory properties. The present study is aimed to elucidate the neuroprotective effect of catechin hydrate (CH), a natural flavanoid with potential antioxidant and anti-inflammatory properties, on intracerebroventricular streptozotocin (ICV-STZ) induced neuronal loss and memory impairment. To test this hypothesis, male Wistar rats were pretreated with CH (10 and 20 mg/kg bwt) orally once daily for 21 days and then bilaterally injected with ICV-STZ (3 mg/kg bwt), while sham group rats receive the same volume of vehicle. After 2 weeks of ICV-STZ infusion, rats were tested for cognitive performance using Morris water maze (MWM) test and then sacrifice for biochemical and histopathological assays. CH was found to be successful in upregulating the antioxidant status and prevented the memory loss. The expression of choline acetyl transferase (ChAT) was decreased in ICV-STZ group and CH pretreatment increases the expression of ChAT. Moreover, inflammatory mediators like TNF-α, IL-1β levels and expression of iNOS were significantly attenuated by CH pretreatment. The study suggests that CH is effective in preventing memory loss, ameliorating the oxidative stress and might be beneficial for the treatment of sporadic dementia of Alzheimer’s type (SDAT).     

Bioaccumulation of Trace Mercury in Trophic Levels of Benthic, Benthopelagic, Pelagic Fish Species, and Sea Birds from Arvand River, Iran

In this study, concentration of mercury was determined in the trophic levels of benthic, benthopelagic, pelagic fish species, and river birds from Arvand River, located in the Khuzestan province in the lowlands of southwestern Iran at the head of the Persian Gulf. The order of mercury concentrations in tissues of the fish species was as follows: liver>gill>muscle and in tissues of the kingfisher species was as follows: feather>liver>kidney>muscle. Therefore, liver in fish and feather in kingfisher exhibited higher mercury concentration than the other tissues. There was a positive correlation between mercury concentrations in fish and kingfisher species with size of its food items. We expected to see higher mercury levels in tissues of female species because they are larger and can eat larger food items. The results of this study show that the highest mean mercury level were found in the kingfisher (Anas crecca), followed by benthic (Epinephelus diacanthus), benthopelagic (Chanos chanos), and pelagic fish (Strongylura strongylura). Mean value of mercury in fish species, S. strongylura were (0.61 μg g^?1 dry weight), C. chanos (0.45 μg g^?1 dry weight), E. diacanthus (0.87 μg g^?1 dry weight), and in kingfisher species A. crecca was (2.64 μg g^?1 dry weight). Significant correlation between mercury concentration in fish and kingfisher may be related to high variability of mercury in the fish.     

A Pilot Study on Neopterin Levels and Tryptophan Degradation in Zinc-Exposed Galvanization Workers

Hot-dip galvanization is a zinc-coating process to protect the metal items from corrosion. Zinc oxide nanoaerosol fume rising from hot metal bath surface in nano dimensions contains the greatest risk for workers in galvanization process. In the present study, it was evaluated whether inhalation of zinc causes any alteration in cellular immunity and tryptophan degradation by measuring neopterin, tryptophan, kynurenine, and zinc levels in 63 male galvanization workers and 23 male office personnel as controls. Serum and urinary zinc levels were found as 14.90?±?0.90 and 102?±?4.7 μg/dL in workers while 12.87?±?1.45 and 75?±?4.2 μg/dL in controls, respectively (both, p?<?0.05). Similarly, the mean urinary neopterin levels and serum neopterin and kynurenine levels were found to be statistically higher in galvanization workers than the controls (all, p?<?0.05). Significant correlations were found between urinary neopterin levels and kynurenine to tryptophan ratio or serum zinc levels. The results indicated cellular immune activation by occupational zinc exposure. It was estimated that neopterin, in parallel with kynurenine pathway, could reflect occupational exposure to zinc nanoaerosols and might be useful in early diagnosis of immune alterations due to nano-scale exposures.     

Slow Regulated Release of H2S Inhibits Oxidative Stress Induced Cell Death by Influencing Certain Key Signaling Molecules

Hydrogen sulphide (H₂S) is one of three gaseous signaling molecules after nitric oxide and carbon monoxide. Various H₂S donor compounds have been synthesized to study its physiological function. Among these compounds sodium hydrosulphide (NaHS), a donor of releasing H₂S rapidly have shown to be protective in certain neuronal cell line but several in vivo studies have generated conflicting data. Furthermore several slow releasing H₂S donors have been shown to have positive effects on cells in culture. The intracellular concentration of H₂S and hence its rate of production may be a factor in keeping the balance between its neuroprotective and toxic effects. The present study was undertaken to deduce how a rapid releasing H₂S donor (NaHS) as opposed to a slow releasing donor (ADTOH), affect oxidative stress related intracellular components and survival of RGC-5 cells. It was concluded that when RGC-5 cells are exposed to the toxic effects of glutamate in combination with buthionine sulfoxime (Glu/BSO), ADTOH was more efficacious in inhibiting apoptosis, scavenging reactive oxygen species (ROS), stimulation of glutathione (GSH) and gluthathione-S-transferase (GST). Western blot and qPCR analysis showed ADTOH increased the levels of Nrf2, HO-1, PKCα, p-Akt, Bcl-2 and XIAP but caused a decrease of Nfκβ and xCT greater than NaHS. This study is first to compare the efficacy of two H₂S donor drugs as potential neuroprotectants and demonstrate that slow regulated release of H₂S to cell culture can be more beneficial in inhibiting oxidative stress induced cell death.     

Enhanced Expression of Glia Maturation Factor Correlates with Glial Activation in the Brain of Triple Transgenic Alzheimer’s Disease Mice

We previously demonstrated that glia maturation factor (GMF), a brain specific protein, isolated, sequenced and cloned in our laboratory, induce expression of proinflammatory cytokines and chemokines in the central nervous system. We also reported that the up-regulation of GMF in astrocytes leads to the destruction of neurons suggesting a novel pathway of GMF-mediated cytotoxicity of brain cells, and implicated its involvement in the pathogenesis of inflammatory neurodegenerative diseases. In the present study, we examined the expressions of GMF in triple-transgenic Alzheimer’s disease (3xTg-AD) mice. Our results show a 13-fold up-regulation of GMF and 8–12-fold up-regulation of proinflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-1β, interferon gamma (IFN-γ), and chemokine (C–C motif) ligand 2 (CCL2) and C–X–C motif chemokine 10 (CXCL10/IP-10) mRNA as determined by quantitative real-time RT-PCR in the brain of 3xTg-AD mice as compared to non-transgenic (Non-Tg) mice. In conclusion, the increase in GMF and cytokine/chemokine expression was correlated with reactive glial fibrillary acidic protein positive astrocytes and ionized calcium binding adaptor molecule 1 (Iba-1)-positive microglia in 3xTg-AD mice.     

Antioxidant and Neuroprotective Effects of Scrophularia striata Extract Against Oxidative Stress-Induced Neurotoxicity

In this study, the neuroprotective effect of Scrophularia striata Boiss (Scrophulariaceae) extract, a plant growing in northeastern of Iran, against oxidative stress-induced neurocytotoxicity in PC12 was evaluated. The PC12 cell line pretreated with different concentrations (10, 50, 100, and 200 μg/ml) of the extract and then treated with H₂O₂ to induce oxidative stress and neurotoxicity. Survival of the cells, reactive oxygen species (ROS) generation, and apoptosis were measured using MTT assay, fluorescent probe 2′,7′-dichlorofluorescein diacetate, and annexin V/propidium iodide, respectively. Moreover, the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) was used to evaluate the antioxidant capacity of the plant extract. Phytochemical assay by thin layer chromatography showed that the main components, including phenolic compounds, phenyl propanoids and flavonoids, were presented in the S. striata extract. The extract in concentrations of 50–200 μg/ml protected PC12 cells from H₂O₂-induced toxicity. The survival of the cells at concentration of 200 μg/ml was 64 % compared to that of H₂O₂ alone-treated cells (48 %) (p < 0.001). The extract also dose-dependently reduced intracellular ROS production (p < 0.001). Moreover, the extract showed antioxidative effects and decreased apoptotic cells. Collectively, these findings indicated the ability of S. striata to decrease ROS generation and cell apoptosis and also suggest the presence of the neuroprotective agents in this plant.     

Microsporum fulvum, an Ignored Pathogenic Dermatophyte: A New Clinical Isolation from Iran

Misidentifying with Microsporum gypseum has for a long time been accounted for less prevalence of the geophilic species, Microsporum fulvum in human dermatophytosis. We describe a new case of infection with the species in an Iranian young man. Direct examination of skin scrapings revealed a tinea corporis, and morphological study of the recovered isolate from the culture resulted in the identification of M. gypseum. However, PCR amplification of ITS1-5.8S rDNA-ITS2 region and subsequent ITS-RFLP and sequencing were indicative of M. fulvum as the true causative agent. To recognize M. fulvum in human infections and to validate the morphologically distinguished isolates of M. gypseum, the genetic-based identification is strongly recommended.     

Severe Disseminated Phaeohyphomycosis in an Immunocompetent Patient Caused by Veronaea botryosa

We present a severe case of disseminated phaeohyphomycosis due to Veronaea botryosa. A 32-year-old female, native from Cuautla, Morelos, Mexico, presented a chronic dermatosis which started 10 years earlier with multiple exophytic, multilobulated, soft, and pedunculated or sessile neoformations of diverse sizes from 2 to 10 cm in diameter, which became verrucose and increased in size. The patient was immunocompetent, and no hereditary or familiar precedents of importance were known. No treatment was given, and the dermatosis remained relatively stable until the patient became pregnant in 2001 and 2003. The infection then exacerbated and worsened, leading to dissemination to the extremities, trunk, and face. The initial diagnosis was chromoblastomycosis which was treated with terbinafine and itraconazole but without visible improvement. Histopathology revealed pigmented, irregular, unbranched, and septate hyphae. Veronaea botryosa was isolated (CBS 127264 = JX566723), and its identity was confirmed by sequencing the internal transcribed spacer (ITS) rDNA. Therapy with posaconazole (800 mg/day) was started showing a gradual improvement of lesions with a reduction in size and flattening of the eruptions.