Lead and calcium crosstalk tempted acrosome damage and hyperpolarization of spermatozoa: signaling and ultra-structural evidences.

BACKGROUND: Exposure of humans and animals to heavy metals is increasing day-by-day; thus, lead even today remains of significant public health concern. According to CDC, blood lead reference value (BLRV) ranges from 3.5 µg/dl to 5 µg/dl in adults. Recently, almost 2.6% decline in male fertility per year has been reported but the cause is not well established. Lead (Pb2+) affects the size of testis, semen quality, and secretory functions of prostate. But the molecular mechanism(s) of lead toxicity in sperm cells is not clear. Thus, present study was undertaken to evaluate the adverse effects of lead acetate at environmentally relevant exposure levels (0.5, 5, 10 and 20 ppm) on functional and molecular dynamics of spermatozoa of bucks following in vitro exposure for 15 min and 3 h. RESULTS: Lead significantly decreased motility, viable count, and motion kinematic patterns of spermatozoa like curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency and maximum amplitude of head lateral displacement even at 5 ppm concentration. Pb2+ modulated intracellular cAMP and Ca2+ levels in sperm cells through L-type calcium channels and induced spontaneous or premature acrosome reaction (AR) by increasing tyrosine phosphorylation of sperm proteins and downregulated mitochondrial transmembrane potential. Lead significantly increased DNA damage and apoptosis as well. Electron microscopy studies revealed Pb2+ -induced deleterious effects on plasma membrane of head and acrosome including collapsed cristae in mitochondria. CONCLUSIONS: Pb2+ not only mimics Ca2+ but also affects cellular targets involved in generation of cAMP, mitochondrial transmembrane potential, and ionic exchange. Lead seems to interact with Ca2+ channels because of charge similarity and probably enters the sperm cell through these channels and results in hyperpolarization. Our findings also indicate lead-induced TP and intracellular Ca2+ release in spermatozoa which in turn may be responsible for premature acrosome exocytosis which is essential feature of capacitation for fertilization. Thus, lead seems to reduce the fertilizing capacity of spermatozoa even at 0.5 ppm concentrations.

Sinapic acid protects against lead acetate-induced lung toxicity by reducing oxidative stress, apoptosis, inflammation, and endoplasmic reticulum stress damage.

Lead acetate (PbAc) is a compound that produces toxicity in many tissues after exposure. Sinapic acid (SNP) possesses many biological and pharmacological properties. This study aimed to investigate the efficacy of SNP on the toxicity of PbAc in lung tissue. PbAc was administered orally at 30 mg/kg and SNP at 5 or 10 mg/kg for 7 days. Biochemical, genetic, and histological methods were used to investigate inflammatory, apoptotic, endoplasmic reticulum stress, and oxidative stress damage levels in lung tissue. SNP administration induced PbAc-reduced antioxidant (GSH, SOD, CAT, and GPx) and expression of HO-1 in lung tissue. It also reduced MDA, induced by PbAc, and thus alleviated oxidative stress. SNP decreased the inflammatory markers NF-κB, TNF-α and IL-1ß levels induced by PbAc in lung tissue and exhibited anti-inflammatory effect. PbAc increased apoptotic Bax, Apaf-1, and Caspase-3 mRNA transcription levels and decreased anti-apoptotic Bcl-2 in lung tissues. SNP decreased apoptotic damage by reversing this situation. On the other hand, SNP regulated these markers and brought them closer to the levels of the control group. PbAc caused prolonged ER stress by increasing the levels of ATF6, PERK, IRE1α, GRP78 and this activity was stopped and tended to retreat with SNP. After evaluating all the data, While PbAc caused toxic damage in lung tissue, SNP showed a protective effect by reducing this damage.

Zinc Phenolsulfonate.

The Expert Panel for Cosmetic Ingredient Safety reviewed newly available studies since their original assessment in 1986 and a previous re-review in 2004, along with updated information regarding product types and concentrations of use. Considering this information, the Panel confirmed that Zinc Phenolsulfonate is safe as a cosmetic ingredient in the present practices of use and concentration as described in this report.

A "turn-on" red cyclometalated iridium (III) complex for long-term tracking the diffusion of CORM-2 in cells and zebrafish.

Transition metal carbonyl compound of CO releasing molecules (CORMs) are widely used to treat arthritis, tumor and immune. They play a physiological role by directly acting on target tissues to release CO for disease treatment without matrix metabolism after dissolution. It is important to track the level and diffusion process of CORMs in vivo to control CO dose and distribution, facilitating to understand the roles of CORMs in disease treatment. Herein, we designed two red ring Ir1/2 complexes with a large stokes shift. Both Ir1 and Ir2 complexes probes can sensitively and selectively respond to CORM-2. The probe Ir1 exhibits rapid reaction with CORM-2 in Phosphate Buffered Saline within 1 min, showing a detection limitation of 0.13 µM and manifesting a linear relationship with the CORM-2 concentration from 0 to 70 µM at λem = 618 nm. Due to low toxicity even after 12 h exposure and fluorescence stability, this probe has been successfully used for continuous tracking the diffusion process of CORM-2 in living cells for up to 60 min and visualizing CORM-2 distribution in zebrafish. Additionally, this probe showed a good capacity for deep penetration (126 µm), suggesting the potential in detecting CORM-2 in living tissues.

Environmental occurrence, biological effects, and health implications of zinc pyrithione: A review.

Due to the detrimental effects on aquatic organisms and ecosystem, tributyltin as a antifouling agent have been banned worldwide since 1990s. As a replacement for tributyltin, zinc pyrithione (ZnPT) has emerged as a new environmentally friendly antifouling agent. However, the widespread use of ZnPT unavoidably leads to the occurrence and accumulation in aquatic environments, especially in waters with limited sunlight. Despite empirical evidence demonstrating the ecotoxicity and health risks of ZnPT to different organisms, there has been no attempt to compile and interpret this data. The present review revealed that over the past 50 years, numerous studies have documented the toxicity of ZnPT in various organisms, both in vitro and in vivo. However, long-term effects and underlying mechanisms of ZnPT on biota, particularly at environmentally realistic exposure levels, remain largely unexplored. In-depth studies are thus necessary to generate detailed ecotoxicological information of ZnPT for environmental risk assessment and management.

Gadolinium-based contrast agents aggravate mechanical and thermal hyperalgesia in a nitroglycerine-induced migraine model in male mice.

In the diagnosis of migraine, which is a neurovascular disease, gadolinium-based contrast agents (GBCAs) are used to rule out more serious conditions. On the other hand, it remains unclear as a scientific gap whether GBCAs may trigger migraine-related pain. The aim of this study was to investigate the effect of GBCAs on mechanical and thermal pain behaviour in a nitroglycerin (NTG)-induced migraine model in mice. NTG (10 mg/kg) was administered intraperitoneally to adult (6-8weeks old) BALB/c mice 2 h before behavioral tests 5 times every other day on days 1st, 3rd, 5th and 9th to induce migraine model (N = 50). As GBCAs, gadobenate dimeglumine (linear-ionic), Gadodiamide (linear-nonionic), and gadobutrol (macrocyclic-nonionic) were delivered intravenously through the tail vein of mice for 5 days on test days. Mechanical pain threshold (plantar and facial withdrawal threshold) was evaluated by plantar von Frey and periorbital von Frey tests on days 1st, 5th, and 9th, and thermal pain threshold (latency) was evaluated by hot plate and cold plate tests on days 3rd and 7th. There was a statistically significant increase in mechanical and thermal hyperalgesia in NTG administered groups compared to the control group. Gadodiamide, gadobutrol and gadobenate dimeglumine administration significantly decreased latency, paw and facial withdrawal threshold (0.18 ± 0.05, 0.17 ± 0.07, 0.16 ± 0.09; 9th day values respectively) compared to NTG group (0.27 ± 0.05). The results of this in vivo study show that GBCAs produce effects that may trigger migraine attacks in migraine. It is recommended that these effects be further investigated and supported by further clinical studies.

Copper pyrithione and zinc pyrithione induce cytotoxicity and neurotoxicity in neuronal/astrocytic co-cultured cells via oxidative stress.

Previous studies on copper pyrithione (CPT) and zinc pyrithione (ZPT) as antifouling agents have mainly focused on marine organisms. Even though CPT and ZPT pose a risk of human exposure, their neurotoxic effects remain to be elucidated. Therefore, in this study, the cytotoxicity and neurotoxicity of CPT and ZPT were evaluated after the exposure of human SH-SY5Y/astrocytic co-cultured cells to them. The results showed that, in a co-culture model, CPT and ZPT induced cytotoxicity in a dose-dependent manner (~ 400 nM). Exposure to CPT and ZPT suppressed all parameters in the neurite outgrowth assays, including neurite length. In particular, exposure led to neurotoxicity at concentrations with low or no cytotoxicity (~ 200 nM). It also downregulated the expression of genes involved in neurodevelopment and maturation and upregulated astrocyte markers. Moreover, CPT and ZPT induced mitochondrial dysfunction and promoted the generation of reactive oxygen species. Notably, N-acetylcysteine treatment showed neuroprotective effects against CPT- and ZPT-mediated toxicity. We concluded that oxidative stress was the major mechanism underlying CPT- and ZPT-induced toxicity in the co-cultured cells.

Immunohistochemical and morphological changes associated with hepatic damage in lead acetate-induced toxicity and mitigatory properties of naringin in cockerel chicks.

Lead (Pb) toxicity constitutes a major health hazard to both humans and animals especially in the developing countries. It is a ubiquitous environmental contaminant found in the air essentially because of unregulated mining and other industrial activities. Lead can be found naturally in the soil thus, contaminating crops for human and animal food, as well as run-off water and air pollution. Intensively and extensively reared domestic chickens are exposed to contamination via inhalation and ingestion of contaminated food materials. Naringin, a product from citrus plant has been described to possess excellent metal chelating ability. Naringin is rich in flavonoid with attendant antioxidant, anti-autophagy, anti-inflammatory, hepatoprotective and cardio-nephroprotective properties. This study was conducted to investigate the hepatoprotective and modulation of oxidative stress in commercial cockerel chickens by Naringin. Thirty-six commercial cockerel chickens were randomly assigned into six groups A-F of six birds each viz: Group A served as control group while groups B, C, and D received Lead acetate at 300 ppm via drinking water continuously till the end of the experiment. In addition, groups C and D were treated with Naringin at 80 mg/kg and 160mg/kg, respectively, via oral gavage for 8 weeks. Groups E and F were administered naringin only at 80mg/kg and 160mg/kg respectively for eight weeks. Pb toxicity induced degenerative changes in the histological sections as well as, higher expression of hepatic caspase 3 as shown by immunohistochemistry. There was increased oxidative stress markers (H2O2, MDA) and depletion of the antioxidant defense system markers SOD, GPx, GSH, and GST. It concluded that Co- treatment with Naringin ameliorated oxidative stress, enhanced antioxidant defense system, reduced the expression of hepatic caspase 3 thus, offering protection against lead acetate-induced derangements in the liver of commercial cockerel chickens.

Effect of an extract of Aloe vera on the biodistribution of sodium pertechnetate (Na99mTcO4) in rats / Efeito de um extrato de Aloe vera na biodistribuição do pertecnetato de sódio (Na99mTcO4) em ratos

PURPOSE: Aloe vera is a tropical plant popularly known in Brazil as babosa. We have investigated the effect of aqueous extract of Aloe vera on the biodistribution of Na99mTcO4 and laboratorial parameters in Wistar rats. METHODS: Twelve animals were divided into treated and control groups. In the treated group, Aloe vera was given by gavage (5mg/mL/day) during 10 days. The control group received sorbitol by the same way and period. One hour after the last dose, we injected 0.1mL of Na99mTcO4 by orbital plexus. After 60 min, all the animals were killed. Samples were harvested from the brain, liver, heart, muscle, pancreas, stomach, femur, kidneys, blood, testis and thyroid and the percentage of radioactivity ( percentATI/g) was determined. Biochemical dosages were performed. RESULTS: There was a significant increase of percentATI/g in blood, femur, kidneys, liver, stomach, testis and thyroid and also in blood levels of AST and ALT. A significant decrease in levels of glucose, cholesterol, triglycerides, creatinine and urea occurred. The statistical analyses were performed by Mann-Whitney test and T-Student test (p<0.05). CONCLUSION: The aqueous extract of Aloe vera facilitated the uptake of Na99mTcO4 in organs of rats and it was responsible to a high increase of levels of AST and ALT.

OBJETIVO: Aloe vera é uma planta tropical popularmente conhecida no Brasil por "babosa". Investigou-se o efeito de extrato aquoso do A. vera na biodistribuição do pertecnetato de sódio (Na99mTcO4) e em parâmetros laboratoriais de ratos Wistar. MÉTODOS: Doze animais foram divididos em 2 grupos: tratado e controle. No grupo tratado, o extrato de A. vera foi administrado via oral (5mg/mL/dia) por 10 dias. O grupo controle recebeu sorbitol do mesmo modo. Uma hora após a última dose, ambos receberam 0,1mL de Na99mTcO4 via plexo orbital. Após 60 minutos, os animais foram sacrificados. Foram retiradas amostras do cérebro, fígado, coração, músculo, pâncreas, estômago, fêmur, rins, sangue, testículos e tiróide e determinou-se o percentual de radioatividade por grama ( por centoATI/g) de cada uma. Dosagens bioquímicas foram realizadas. RESULTADOS: Houve um aumento significativo do por centoATI/g no sangue, fêmur, rins, fígado, estômago, testículos e tiróide e nos níveis sanguíneos das enzimas AST e ALT. Ocorreu uma diminuição significativa dos níveis de glicose, colesterol, triglicérides, creatinina e uréia. Análises estatísticas foram feitas pelos testes de Mann-Whitney e T-student (p<0,05). CONCLUSÃO: O extrato aquoso de A. vera facilitou a captação do Na99mTcO4 em órgãos de ratos e foi responsável pelo aumento dos níveis de AST e ALT.

Avaliação do efeito cumulativo do antimoniato de meglumina sobre a prole de camundongos swiss: ensaio biológico / Evaluate the cumulative effect of meglumine antimoniate on the progeny of swiss mice: biologic assay

OBJETIVOS: Avaliar o efeito do antimoniato de meglumina na transferência materno-fetal na geração F1 (prole de matrizes expostas ao composto), e conseqüências em progênies F2. MÉTODOS: Camundongos fêmeas Swiss foram tratados com antimoniato de meglumina, via subcutânea, com administração diária, do sétimo ao 12º dia de gestação (ddg), na dose equivalente a 100mgSb v/kg peso/dia. O grupo controle recebeu apenas o veículo (água destilada). Após o nascimento da prole (geração F1), 59 fêmeas foram examinadas diariamente para determinação do ciclo estral. Quando determinado o ciclo estro, acasalou-se 18 fêmeas com machos da mesma linhagem. No 18º ddg, as fêmeas foram eutanasiadas por câmara de CO2, o abdômen incisado e o útero exposto, quando avaliou-se os sítios de desenvolvimento embrionário e fetal quanto ao número de reabsorções, fetos vivos e mortos. Todos os fetos e placentas foram pesados para calcular o índice placentário. Três placentas de cada ninhada foram separadas para análise microscópica. RESULTADOS: A exposição ao antimoniato de meglumina não interferiu no ciclo estral dos animais tratados, pelo fato de não alterar o intervalo precoital e o índice de fertilidade. Não foram observadas alterações placentárias em progênies F2. CONCLUSÃO: O antimoniato de meglumina não altera a performance reprodutiva das mães expostas cronicamente. Estes dados sugerem que ocorre uma gradual eliminação do antimoniato de meglumina no organismo materno, sem acarretar danos a proles futuras.

OBJECTIVES: Evaluate the effect of Meglumine Antimoniate on maternal-fetal transference in F1 generations (offspring of dams exposed to the drug), and embryotoxicity in F2 generations. METHODS: Female Swiss mice were treated with daily s.c. injection of Meglumine Antimoniate (100mgSb v/kg bw/day) from day 7 until day 12 of pregnancy. The control group received only the vehicle (distilled water). After birth of offspring (F1 generation), 59 females were examined daily for determination of the estral cycle. When the cycle estrus was determined, males were mated with 18 females of the same lineage. On day 18 of pregnancy, females were euthanasied in a chamber of CO2 and after incision of the abdomen, the uterus was exposed. Then, resorptions as well as living and dead fetuses were evaluated, also the number of embryo/fetal implantation sites. Fetuses and their placenta were weighted to calculate the placental index. Three placentas of each litter were separated for microscopic analysis. RESULTS: Administration of the Meglumine Antimoniate did not interfere in the estral cycle of the treated group, since it did not alter the precoital interval and fertility index. Placenta alterations were not observed in the F2 generations. CONCLUSION: Meglumine Antimoniate did not interfere in the reproductive performance, after chronic exposition of dams. Data suggest that there is a gradual elimination of Meglumine Antimoniate by the maternal organism without damaging the future offspring.

El plomo inhibe la corriente activada por protones (ASIC) en las neuronas de los ganglios dorsales / Lead inhibits proton gated currents (ASIC) in dorsal root ganglion neurons

Antecedentes. Los canales iónicos ASIC (del inglés Acid Sensing Ion Channel) son canales iónicos activados por reducciones transitorias en el pH extracelular. Pese a no conocerse con exactitud su mecanismo, la activación ocurre por medio de la unión de protones al dominio extracelular del canal y es modulada por iones calcio y zinc. Objetivo. El hecho de que los cationes divalentes modifiquen el funcionamiento del canal nos llevó a preguntar si el plomo, otro catión divalente, sería capaz de alterar el funcionamiento de los ASIC. Métodos y resultados. Mediante el uso de la técnica de fijación de voltaje en configuración de célula completa en las neuronas de los ganglios de la raíz dorsal de la rata, encontramos que el plomo inhibe la corriente ASIC en forma dependiente de la concentración. Conclusiones. Estos resultados contribuyen a definir los mecanismos de activación de los canales ASIC y a explicar algunos de los mecanismos tóxicos del plomo en el organismo.

BACKGROUND: Acid sensing ion channels (ASIC) are ionic channels activated by transient pH reductions in the ext raceilularenvi ronment. Although the activation mechanism is not fully elucidated, it is clear that the channel is activated by proton binding to its extraceilular domain, a process that is modulated by calcium and zinc. OBJECTIVE: The fact that divalent cations are able to modify ASIC operation, lead us to consider if lead, anotherdivalent cation and widely distributed neurotoxicant, is also capable to affect ASIC function. METHODS: For this purpose, we recordedASiC currents in rat dorsal root ganglion neurons using the whole cell patch-clamp technique. RESULTS: The results indicated that lead inhibits ASIC currents in a concentration -dependent fashion. CONCLUSIONS: These results contribute to the understanding of the activation mechanism of ASIC and to explain some of the toxic mechanisms of lead in the organism.

Pentavalent antimonial nephrotoxicity in the rat

Estudou-se a funcao renal de ratos tratados com Glucantime (Antimoniato de Meglumine, Rhodia) e Pentostam (estibogloconato de Sodio, Wellcome) na dose de 30 mg de "Sb POT v" por 100g de peso por dia, durante 30 dias. Observou-se um disturbio na concentracao urinaria, que foi reversivel 7 dias apos cessada a administracao das drogas. O estudo histopatologico do rim, por meio da microscopia optica, nao evidenciou alteracoes significativas. Por outro lado, ratos tratados com altas doses dos antimoniais (220mg de "Sb POT v" por 100g de peso por dia) mostraram alteracoes funcionais e histopatologicas renais compativeis com necrose tubular aguda

Chronic lead exposure induces alterations on local circuit neurons

Se estudiaron los efectos de la exposición crónica por plomo en ratas lactantes, particularmente en las neuronas de circuito local (LCN) del hipocampo. La administración del plomo se inició en la primera semana de vida de la cría, a través de la leche de la madre. Durante la lactancia el agua de bebida de la madre contenía 1 g% de acetato de plomo (p/v) dosis subclínica. Después de destete las ratas jóvenes fueron tratadas con la misma concentración de agua adulterada con plomo. Los estudios con el microscopio electrónico se realizaron a los 30, 45, 60, 75 y 90 días de edad. Después de 2 meses de exposición al plomo se encontraron bordes irregulares y citoplasma condensado en las células no piramidales, en cesto y granulosas. En el neuropilo se vieron ciertos axones y terminales sináptico, así como algunas dendritas lisas en forma de cuentas de rosario, más condensadas y oscuras que los elementos circundantes. Coincidente con las alteraciones de las LCN, los astrocitos mostraron un aumento de los gliofilamentos. Estos resultados sugieren que la actividad funcional de las LCN podría modificarse por los cambios observados. Estas alteraciones constituirían el sustrato morfológico de pequeños cambios neuropsicológicos observados en ratas expuestas a concentraciones relativamente bajas de plomo