Distribution of 2,4,5-trichlorophenoxyacetic acid in the mouse fetus

The herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) readily crosses the placenta in the mouse on gestational day 13. Concentrations of 2,4,5-T in maternal tissues and fetuses were obvious at 30 min, highest at 8 h, diminished by 24 h and almost entirely eliminated by 48 h. Autoradiographs of the whole fetus showed that initially 2,4,5-T was mainly in the highly vascularized tissues such as liver followed by the skin, eyes and ventricles of the brain. At 48 h, there was a general distribution of 2,4,5-T in the skeletal muscles. None was detected in the palate. The excretion rate in the mouse was approx. 60 gm/h; about 52% of the dose was recovered unchanged in the urine in 24 h.     

Evaluation of renal function in saccharin treated rats

Renal function and transport have been examined in male and female rats at various times during a 6-month exposure to sodium saccharin. The animals were maintained on special diets containing 0%, 1%, 5% or 7.5% sodium saccharin. Development patterns for renal transport and renal function in the control animals were normal. The 5% and 7.5% concentrations of saccharin caused a reduction in the renal slice steady-state accumulation of p-aminohippurate (PAH) and tetraethylammonium (TEA) which became significant after the animals were 30 days of age or older. Enhanced sodium excretion was observed in every age group of animals tested when these animals consumed sodium saccharin concentrations ? 1% in the diet. At 60 days of age, increased urine volume, a decrease in urine osmolality, and increased potassium excretion were also found. All effects of saccharin on renal function and transport were promptly and completely reversible when the animals were removed from the saccharin diet for as little as 24 h. The effects of saccharin on PAH transport apparently were attributable to competitive inhibition. Although effects on TEA transport and other renal function parameters were not defined as to mechanism, the effects were as readily reversible as those on PAH when saccharin was removed from the diet.     

Teratogenic and toxicological examination of 2,4,5-trichlorphenoxyacetic acid in developing chick embryos

Practical grade 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), dissolved in dimethylsufoxide (DMSO), was injected into the air space of fertilized chicken eggs prior to incubation. Doses of 2,4,5-T administered were 12.5, 25, 50, 75, 100, and 125 mg/kg to determine herbicide toxicity on the first day of incubation. A similar group was studied on day 5 of incubation with doses of 2,4,5-T at 50, 75, 100 and 250 mg/kg. LD₅₀ was estimated to be 62 mg/kg on day zero and 68 mg/kg on day 5. Additional, embryos were exposed to 2,4,5-T at 50 mg/kg on day zero of gestation and sacrificed after 48 h of incubation. Serial sections were examined for teratological and developmental anomalies. None were found.     

Toxicological implications of pesticides: their toxic effects on seeds of food plants.

Pesticides are widely used for the protection of economic crops from a variety of noxious pests. The repeated and indiscriminate uses and the extreme stability of certain pesticides have led to their accumulation in plants, animals, soils and sediments, thus effecting widespread contamination of the environment. Soil contaminants are especially serious because they can inhibit or impair the seed germination of our food and feed crops. Seeds can come in close contact with pesticides through processes such as prematurity application, fumigation, seed dressings, and seed treatments. Several reports have indicated the toxic effects of pesticides on seed germination. Possible mechanisms of the toxic action on pesticides during the germination of seeds have been discussed with emphasis on biochemical, histological, and cytological alterations. Bioassay procedures employing seed germination as a smiple, feasible, economical, time-saving indicator of toxicity have been described briefly. Attention is then drawn to the possible potential health hazards arising from the presence of pesticidal chemicals in food plants since the toxicological implications of long term exposure to pesticides are often more far-reaching.     

Effects of anionic xenobiotics on rat kidney: I—tissue and mitochondrial respiration

The polar 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) metabolite, 2,2-bis p-chlorophenyl)acetic acid (DDA), and the phenoxyacetic acid herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), were previously shown to be accumulated to high levels in liver and kidney via the organic acid transport system, raising the possibility of organ-specific toxicity secondary to transport. In these studies, accumulation of DDA was shown to depress oxygen consumption by renal cortical slices at high doses (0.1 and 1 mM). Isolated renal and hepatic mitochondria were uncoupled by low doses of DDA (5–10 nmoles/mg mitochondrial protein). Maximal uncoupling was seen at 50–70 nmoles/mg. 2,4-D and 2,4,5-T also produced uncoupling, but at doses of 70 nmoles/mg or higher. All agents were more effective with α-ketoglutarate or pyruvatemalate as substrate than with succinate. With succinate as substrate (but not α-ketoglutarate or pyruvate-malate), all three agents also depressed State 3 (ADP-stimulated) respiration. Again. DDA was more effective than 2,4-D or 2,4,5-T. These results suggest that accumulation of these or other anionic xenobiotics may lead to toxicity in those tissues possessing the organic anion transport system.     

Uptake of phenoxyacetic acid derivatives into Caco-2 cells by the monocarboxylic acid transporters

The uptake mechanism of phenoxyacetic acid (PA) and its chlorine derivatives, 4-chlorophenoxyacetic acid (4-CPA), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), was investigated using Caco-2 cells. The cells were incubated with PA, 4-CPA, 2,4-D or 2,4,5-T at pH 6.0 and 37 °C. The order of uptake and lipophilicity expressed by n-octanol partition coefficients were PA < 4-CPA < 2,4-D < 2,4,5-T. Incubation at 4 °C or at pH 7.4 significantly decreased these uptake. Furthermore, pretreatment with the protonophore, carbonylcyanide-p-(trifluoromethoxy) phenylhydrazone, or coincubation with benzoic acid, a typical substrate for the proton-linked monocarboxylic acid transporters (MCTs), significantly decreased the uptake of all compounds. The initial uptake rates of all compounds except PA were apparently saturable, suggesting the involvement of a carrier-mediated process. The order of uptake clearance of the compounds was the same as the order of their uptake and lipophilicity. Preloading of cells with benzoic acid significantly increased their uptake except for PA. These results suggest that the uptake of PA, 4-CPA, 2,4-D and 2,4,5-T from the apical membrane of Caco-2 cells is mediated via common MCTs shared, at least in part, with benzoic acid, and the increase in lipophilicity due to the chlor-substitution may increase uptake via the MCTs.     

Mangosteen xanthones mitigate ovalbumin-induced airway inflammation in a mouse model of asthma

α- and γ-Mangostin, which are the major xanthones purified from a Mangosteen, Garcinia mangostana Linn., exhibit a wide range of anticancer, antioxidant, and anti-inflammatory activities. Here, we assessed their therapeutic effects in a mouse model of ovalbumin (OVA)-induced allergic asthma. Animals were treated with α- and γ-mangostins orally for 3 days at doses of 10 and 30 mg/kg daily, 1 h before the OVA challenge. Administration of α- and γ-mangostins significantly reduced the major pathophysiological features of allergic asthma, including inflammatory cell recruitment into the airway, airway hyperresponsiveness (AHR), and increased levels of Th2 cytokines. In addition, α- and γ-mangostins attenuated the increases in phosphoinositide 3-kinase (PI3K) activity, phosphorylation of Akt, and NF-κB in nuclear protein extracts after OVA challenge. In conclusion, α- and γ-mangostin may have therapeutic potential for the treatment of allergic asthma.     

奥美拉唑促小鼠胃癌发生的机制研究

【】目的：研究奥美拉唑(omeprazole, ome)是否会增加小鼠胃癌的发病率并探讨其可能存在的机制。方法：实验分为单纯对照组、ome低剂量组(6mg/kg)、ome高剂量组(30mg/kg)、甲基硝基亚硝基胍(N-methyl-N"-nitro-N-nitrosoguanidine, MNNG)组、MNNG ome低剂量组、MNNG ome高剂量组,MNNG加入饮用水中(100mg/L)小鼠自由饮用。每组7只小鼠,常规饲养24周后处死小鼠收集标本并计算小鼠脾脏重量指数,HE染色观察小鼠胃病理形态学改变,ELISA法检测小鼠血清及脾脏中酸性磷酸酶(acid phosphatase, ACP)、N-乙酰-β-D-氨基葡萄糖苷酶(N-acetyl-β-D-glucosaminidase, NAG)含量; Western Blotting检测小鼠胃P21、P53、mTOR表达。结果：ome组与对照组相比及MNNG组与ome 组相比,小鼠脾重指数、血清及脾脏中溶酶体酶活性明显下降;与MNNG组相比ome 组小鼠胃癌发生率明显增加,尤其是MNNG ome高剂量组,两者差异具有统计学意义(P<0.05); 和对照组相比,实验组p53表达增加,p21表达减少,mTOR表达减少,差异均有统计学意义(P<0.05)。结论：Ome可以促进胃癌发生,其机制可能是和抑制小鼠体内溶酶体及其水解酶的活性,从而降低小鼠免疫功能有关。     

Effects of in utero meso-2,3-dimercaptosuccinic acid with calcium and ascorbic acid on lead-induced fetal development

To examine the effects of meso-2,3-dimercaptosuccinic acid (DMSA) on developmental toxicity resulting from exposure to lead in utero, female albino mice were exposed to lead by drinking water contaminated with lead acetate for 4 weeks. After the cessation of lead exposure, female mice were supplemented by gavage with saline solution, DMSA, or DMSA and calcium as well as ascorbic acid from the fourth day of gestation until parturition, respectively. Lead levels (blood, liver, and bone) were measured at birth. Pups were then tested about neural development including surface righting reflex, cliff avoidance and air righting reflex. The markers of physical maturation, such as body weight, pinna unfolding, incisor eruption, and eye opening were also recorded. DMSA treatment decreased blood lead levels of pregnant mice, however, increased lead levels in both liver and bone of fetus, and delayed the early physical and neural development of offspring. Calcium and ascorbic acid reduced the transfer of lead to fetus. In conclusion, DMSA treatment during pregnancy enhances lead-induced fetal developmental toxicity.     

Ascorbic acid protects against lipopolysaccharide-induced intra-uterine fetal death and intra-uterine growth retardation in mice

Lipopolysaccharide (LPS) has been associated with adverse developmental outcomes including embryonic resorption, intra-uterine fetal death (IUFD), intra-uterine growth retardation (IUGR) and preterm labor. Reactive oxygen species (ROS) mediate LPS-induced developmental toxicity. Ascorbic acid is an antioxidant. In the present study, we investigated the effect of ascorbic acid on LPS-induced IUFD and IUGR in mice. All ICR pregnant mice except controls received an intraperitoneal (75 microg/kg, i.p.) injection of LPS daily on gd 15-17. The experiment was carried out in three different modes. In mode A, the pregnant mice were pretreated with a single dose (500 mg/kg, i.p.) of ascorbic acid before LPS. In mode B, the pregnant mice were administered with a single dose (500 mg/kg, i.p.) of ascorbic acid at 3h after LPS. In mode C, the pregnant mice were administered with 500 mg/kg (i.p.) of ascorbic acid at 30 min before LPS, followed by additional dose (500 mg/kg, i.p.) of ascorbic acid at 3h after LPS. The number of live fetuses, dead fetuses and resorption sites was counted on gd 18. Live fetuses in each litter were weighed. Crown-rump and tail lengths were examined and skeletal development was evaluated. Results showed that maternally administered LPS significantly increased fetal mortality, decreased fetal weight and crown-rump and tail lengths of live fetuses, and retarded skeletal ossification in caudal vertebrae, anterior and posterior phalanges, and supraoccipital bone. LPS-induced IUFD and IUGR were associated with lipid peroxidation and GSH depletion in maternal liver, placenta and fetal liver. Pre-treatment with ascorbic acid significantly attenuated LPS-induced lipid peroxidation, decreased fetal mortality, and reversed LPS-induced fetal growth and skeletal development retardation. By contrast to pre-treatment, post-treatment with ascorbic acid had less effect on LPS-induced IUFD, although post-treatment significantly attenuated LPS-induced lipid peroxidation and reversed LPS-induced fetal growth and skeletal development retardation. Furthermore, post-treatment with ascorbic acid reduced the protective effects of pre-treatment on LPS-induced IUFD. All these results suggest that pre-treatment with ascorbic acid protected against LPS-induced fetal death and reversed LPS-induced growth and skeletal development retardation via counteracting LPS-induced oxidative stress, whereas post-treatment had less effect on LPS-induced IUFD.     

The dietary administration of monosodium glutamate or glutamic acid to C-57 black mice for two years

l-Monosodium glutamate, dl-monosodium glutamate (dl-MSG) and l-glutamic acid (l-GA) were each incorporated at levels of 1.0 and 4.0% w/w in the diets of male C-57 black mice for 715 days. Mortality and disease, some of which was attributable to fighting and attendant injury, did not differ significantly from the findings in control mice, and there was no evidence of malignancy. The only tumour detected was a single benign adenoma of the lung in a mouse receiving 1% dl-MSG.     

Reversible suppression of spermiogenesis in beagle dogs following overdosage with the narcotic analgesic cogazocine lactate

Acute single overdosage (1.0 mg/kg, i.m.) with the novel benzmorphan narcotic analgesic agent Cogazocine lactate lowered serum LH and testosterone concentrations of Beagle dogs. The effect was rapidly reversible and persisted for less than 24 h after drug administration. Repeated administration (1.0 mg/kg, i.m.) induced reversible suppression of spermatid maturation with subsequent effects on semen characteristics. Examination of circulating LH and testosterone concentrations, together with pituitary and prostate morphology, suggested that the changes were due to inhibition of LH release. It is probable that the underlying mechanism is an exaggerated pharmacological response to repeated overdosage, common to many potent narcotic analgesic agents.     

Effect of various antibiotics on modulation of intestinal microbiota and bile acid profile in mice

Antibiotic treatments have been used to modulate intestinal bacteria and investigate the role of intestinal bacteria on bile acid (BA) homeostasis. However, knowledge on which intestinal bacteria and bile acids are modified by antibiotics is limited. In the present study, mice were administered various antibiotics, 47 of the most abundant bacterial species in intestine, as well as individual BAs in plasma, liver, and intestine were quantified. Compared to the two antibiotic combinations (vancomycin + imipenem and cephalothin + neomycin), the three single antibiotics (metronidazole, ciprofloxacin and aztreonam) have less effect on intestinal bacterial profiles, and thus on host BA profiles and mRNA expression of genes that are important for BA homeostasis. The two antibiotic combinations decreased the ratio of Firmicutes to Bacteroidetes in intestine, as well as most secondary BAs in serum, liver and intestine. Additionally, the two antibiotic combinations significantly increased mRNA of the hepatic BA uptake transporters (Ntcp and Oatp1b2) and canalicular BA efflux transporters (Bsep and Mrp2), but decreased mRNA of the hepatic BA synthetic enzyme Cyp8b1, suggesting an elevated enterohepatic circulation of BAs. Interestingly, the two antibiotic combinations tended to have opposite effect on the mRNAs of most intestinal genes, which tended to be inhibited by vancomycin + imipenem but stimulated by cephalothin + neomycin. To conclude, the present study clearly shows that various antibiotics have distinct effects on modulating intestinal bacteria and host BA metabolism.     

Cryopyrin-associated periodic syndromes: development of a patient-reported outcomes instrument to assess the pattern and severity of clinical disease activity

ABSTRACT

Objective: Development of an instrument for characterization of symptom patterns and severity in patients with cryopyrin-associated periodic syndromes (CAPS).

Methods: Two generations of daily health assessment forms (DHAFs) were evaluated in this study. The first-generation DHAF queried 11 symptoms. Analyses of results obtained with that instrument identified five symptoms included in a revised second-generation DHAF that was tested for internal consistency and test–retest reliability. This DHAF was also assessed during the initial portion of a phase 3 clinical study of CAPS treatment.

Results: Forty-eight CAPS patients provided data for the first-generation DHAFs. Five symptoms (rash, fever, joint pain, eye redness/pain, and fatigue) were included in the revised second-generation DHAF. Symptom severity was highly variable during all study phases with as many as 89% of patients reporting at least one symptom flare, and percentages of days with flares reaching 58% during evaluation of the second-generation instrument. Mean composite key symptom scores (KSSs) computed during evaluation of the second-generation DHAF correlated well with Physician's Global Assessment of Disease Activity (r = 0.91, p < 0.0001) and patient reports of limitations of daily activities (r = 0.68, p < 0.0001). Test–retest reliability and Cronbach's α‘s were high (0.93 and 0.94, respectively) for the second-generation DHAF. Further evaluation of this DHAF during a baseline period and placebo treatment in a phase 3 clinical study of CAPS patients indicated strong correlations between baseline KSS and Physician's Global Assessment of Disease Activity. Cronbach's α‘s at baseline and test–retest reliability were also high. Potentially important study limitations include small sample size, the lack of a standard tool for CAPS symptom assessment against which to validate the DHAF, and no assessment of the instrument's responsivity to CAPS therapy.

Conclusions: The DHAF is a new instrument that may be useful for capturing symptom patterns and severity in CAPS patients and monitoring responses to therapies for these conditions.     

Effects of the interferon inducing agents tilorone and polyriboinosinic acid · polyribocytidylic acid (poly IC) on the hepatic monooxygenase systems of pregnant and fetal rats

Interferon inducing agents, including tilorone and polyriboinosinic acid polyribocytidylic acid (poiy IC), are known to depress hepatic cytochrome P-450-dependent monooxygenase systems and the induction of these systems by phenobarbital (PB) and 3-methylcholanthrene (MC) in mature male rats. The current study investigated the effects of tilorone and poly IC on the cytochrome P-450 systems of non-induced, PB-induced, MC-induced and pregnenolonecarbonitrile (PCN)-induced pregnant rats and their fetuses. Pregnant rats received either tilorone or poly IC and saline, PB, MC or PCN, and microsomes from their livers and those of their fetuses were examiued for cytochrome P-450 content, aminopyrine (AP) N-demethylase activity and benxo[a]pyrene (BP) hydroxylase activity. The generalixation can be made from these studies that, when the interferon inducing agents caused changes in cytochrome P-450 content or monooxygenase activities of either induced (PB, MC or PCN) or non-induced (saline) animals, decreases were seen in maternal livers and increases in fetal livers. Thus, in maternal livers tilorone depressed cytochrome P-450 and AP N-demethylase activity in non-induced and PB-, MC- and PCN-induced rats and BP hydroxylase activity in the induced animals; BP hydroxylase activity was not depressed in non-induced maternal livers. Poly IC depressed cytochrome P-450 and AP N-demethylase activity in non-induced and PB-induced rats but not in PCN-induced animals. BP hydroxylase was depressed by poly IC in both PB- and PCN-induced animals. Fetal hepatic cytochrome P-450 and monooxygenase activities were increased by tilorone in PB- and PCN-induced rats but not in non-induced or MC-induced animals. Poly IC increased cytochrome P-450 and both monooxygenase activities in PB- and PCN-induced fetal livers, whereas only BP hydroxylase activity was increased in the fetuses of non-induced rats. Several possible explanations are offered for the opposite effects produced by interferon inducing agents in maternal and fetal livers. Unlike maternally administered tilorone, which induced fetal cytocbrome P-450 and monooxygenase activities in the liver, intrauterine tilorone depressed cytochrome P-450 and had no effect on AP N-demethylase or BP hydroxylase activities in the fetal liver. Intrauterine poly IC was without effect on the cytochrome P-450 systems of the fetal liver. Treatment of pregnant rats with tilorone on days 17–20 of gestation inhibited normal maternal weight gain and produced overt signs of toxicity. A dose of 10 mg/kg of poly IC was very toxic in pregnant rats but produced no overt signs of toxicity in virgin female rats. Time courses of the depressant effects of a single injection of poly IC were observed in mid-term pregnant, late-term pregnant, lactating and adult virgin females. Maximum losses of cytochrome P-450 and ethyhnorphine (EM) N-demethylase activity were seen 48 hr after poly IC administration to pregnant and virgin rats, and recoveries were complete within 96 hr. Similar results were observed in lactating rats except that the nadir occurred at 24 rather than at 48 hr. The response of BP hydroxylase activity to poly IC was qualitatively similar except that this activity was not depressed in the mid-term pregnant rats.     

Fatty acid amide hydrolase blockade attenuates the development of collagen-induced arthritis and related thermal hyperalgesia in mice

Fatty acid amide hydrolase (FAAH) is the primary degradative enzyme of the endocannabinoid anandamide (N-arachidonoylethanolamine), which activates cannabinoid CB₁ and CB₂ receptors. FAAH disruption reduces nociception in a variety of acute rodent models of inflammatory pain. The present study investigated whether these actions extend to the chronic, collagen-induced arthritis (CIA) model. We investigated the anti-arthritic and anti-hyperalgesic effects of genetic deletion or pharmacological inhibition of FAAH in the CIA model. FAAH (−/−) mice, and FAAH-NS mice that express FAAH exclusively in nervous tissue, displayed decreased severity of CIA and associated hyperalgesia. These phenotypic anti-arthritic effects were prevented by repeated daily injections of the CB₂ receptor antagonist, SR144528, but not the CB₁ receptor antagonist rimonabant. Similarly, repeated administration of the FAAH inhibitor URB597 reduced CIA severity, and acute administration of rimonabant, but not SR144528, blocked the anti-hyperalgesic effects of prolonged FAAH inhibition, suggesting that prolonged CB₂ receptor activation reduces the severity of CIA, whereas acute CB₁ receptor activation reduces CIA-induced hyperalgesia. In contrast, acute administration of URB597 elicited a CB₁ receptor-dependent anti-hyperalgesic effect. The observed anti-arthritic and anti-hyperalgesic properties of FAAH inhibition, coupled with a lack of apparent behavioral alterations, suggest that endocannabinoid modulating enzymes offer a promising therapeutic target for the development of novel pharmacological approaches to treat rheumatoid arthritis and associated hyperalgesia.     

Acute exposure of mice to hydrochloric acid leads to the development of chronic lung injury and pulmonary fibrosis

Objective: Accidental exposure to hydrochloric acid (HCl) is associated with acute lung injury in humans, development of long-term chronic airway obstruction, and fibrosis. However, the mechanisms responsible for the progression to pulmonary fibrosis remain unclear. We utilized a mouse model of progressive lung injury from a single exposure to HCl to investigate the effects of HCl on the lower respiratory tract.

Materials and methods: HCl (0.05–0.3?N) or saline was injected intratracheally into male C57Bl/6J mice. At 1, 4, 10 and 30 days post instillation, bronchoalveolar lavage fluid (BALF) and lung tissues were collected and examined for multiple outcomes.

Results and discussion: We observed an early inflammatory response and a late mild inflammation present even at 30?d post HCl exposure. Mice treated with HCl exhibited higher total leukocyte and protein levels in the BALF compared to the vehicle group. This was characterized by increased number of neutrophils, monocytes, and lymphocytes as well as pro-inflammatory cytokines during the first 4?d of injury. The late inflammatory response exhibited a predominant presence of mononuclear cells, increased permeability to protein, and higher levels of the pro-fibrotic mediator TGFβ. Pro-fibrotic protein biomarkers, phosphorylated ERK, and HSP90, were also overexpressed at 10 and 30?d following HCl exposure. In vivo lung function measurements demonstrated lung dysfunction and chronic lung injury associated with increased lung hydroxyproline content and increased expression of extracellular matrix (ECM) proteins. The acute inflammation and severity of fibrosis increased in HCl-concentration dependent manner.

Conclusions: Our findings suggest that the initial inflammatory response and pro-fibrotic biomarker upregulation may be linked to the progression of pulmonary fibrosis and airway dysfunction and may represent valuable therapeutic targets.     

Toxicokinetics of domoic acid in the fetal rat

Domoic acid (DA) is a potent neurotoxin that has both marine wildlife and human health impacts, including developmental effects during prenatal exposure in rodent models. However, little is known regarding DA toxicokinetics in the fetal unit during maternal-fetal transfer. Tissue distribution and toxicokinetics of DA were investigated in pregnant rats and their pups just prior to birth at gestational day 20. Pregnant Sprague Dawley rats were given an intravenous dose of 1.0 mg DA/kg and samples of maternal plasma, fetal plasma, placenta, amniotic fluid and fetal brain were taken at intervals over 24 h. Toxicokinetic parameters were determined using WinNonLin software analysis. Maternal plasma DA log concentration-time curves fit a two compartment pharmacokinetic profile, with alpha and beta half-lives of elimination of 26.9 and 297 min, respectively. Placenta had a C(max) of 752 ng/mL and a terminal half-life of 577 min. Maternal-fetal transfer between the plasma compartments was 31% with a fetal plasma C(max) of 86 ng/mL at 60 min and terminal half-life of 553 min. Amniotic fluid and fetal brain had overall averages of 27±12 ng/mL and 8.12 ng/g, respectively, and did not show evidence of elimination over 24 h. The longer fetal retention of DA, particularly in amniotic fluid, indicates that the fetus may be continually re-exposed during gestation, which could potentially lead to a disease state even at small exposure dose. This has implications for the California sea lions (Zalophus californianus), which exhibit an epilepsy-like disease that arises months after DA producing blooms.     

Effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in mice exposed to cocaine

Objective:

To investigate the effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in experimental animals exposed to cocaine.

Materials and Methods:

Mice were used in this study and were divided randomly into different groups of six animals each. They were either treated with intraperitoneal injection of saline or cocaine hydrochloride or an oral feeding of oil of Ocimum sanctum, ascorbic acid or verapamil, or both (ascorbic acid and verapamil), and were evaluated for a respiratory burst of macrophages, superoxide and nitric oxide (NO) production, estimation of TNF-α in the serum and supernatant of cultured macrophages, estimation of lipid peroxidation (malondialdehyde- MDA) in the serum, and superoxide dismutase activity in the erythrocytes.

Results:

Unstimulated respiratory burst as well as superoxide production was enhanced on treatment with cocaine and all the three drugs were found to attenuate this enhancement. The bactericidal capacity of macrophages decreased significantly on chronic cocaine exposure, as it was associated with decreased respiratory burst and superoxide production. There was a significant decrease in NO production by macrophages on chronic cocaine exposure and all the test drugs were found to restore nitrite formation to a normal level. There was an increase in the malonylodialdehyde (MDA) level and decrease in the superoxide dismutase level on chronic cocaine exposure, and all the three drugs effectively decreased the MDA level and increased superoxide dismutase level. There was an increase in serum TNF-α on chronic cocaine exposure, which was decreased significantly by ascorbic acid and verapamil.

Conclusion:

O. sanctum, ascorbic acid, and verapamil were equally effective in improving the macrophage function and reducing oxidative stress. These findings suggested that O. sanctum, ascorbic acid, and verapamil attenuated acute and chronic cocaine-mediated effects.     

Synergistic effects of pyrrolizidine alkaloids and lipopolysaccharide on preterm delivery and intrauterine fetal death in mice

Preterm birth is the leading cause of death for newborn infants, and lipopolysaccharide (LPS) is commonly used to induce preterm delivery in experimental animals. Pyrrolizidine alkaloids (PAs) are widespread and occur in foods, herbs, and other plants. This study was to investigate the synergistic effects of LPS and two representative PAs, retrorsine (RTS) and monocrotaline (MCT), on preterm delivery and fetal death. Pregnant Kunming mice were divided into seven groups: control, RTS, MCT, LPS, RTS + LPS and two MCT + LPS groups. Animals in PAs and PAs + LPS groups were dosed intragastrically with RTS (10 mg/kg) or MCT (20 mg/kg or 60 mg/kg) from gestational day (GD) 9 to GD16; mice given LPS were injected intraperitoneally with 150 μg/kg on GD15.5. Latencies to delivery, numbers of pups live and dead at birth were recorded, and livers of live neonates were collected. The incidence of LPS-induced preterm birth was enhanced in dams pretreated with MCT, and combination of PAs and LPS increased fetal mortality from PAs. The enhancement of LPS-induced preterm delivery and fetal demise in animals exposed chronically to PAs and other substances found in foods and beverages consumed widely by humans merits further focused investigation.