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1.
Int J Mol Sci ; 21(7)2020 Apr 04.
Article in English | MEDLINE | ID: mdl-32260390

ABSTRACT

The rhizome of Anemarrhena asphodeloides Bunge, used in Traditional Chinese Medicine as a brain function-improving herb, is a promising source of neuroprotective substances. The aim of this study was to evaluate the protective action of xanthones from A. asphodeloides rhizomes on the PC12 cell line exposed to the neurotoxic agent-3-nitropropionic acid (3-NP). The xanthone-enriched fraction of the ethanolic extract of A. asphodeloides (abbreviated from now on as XF, for the Xanthone Fraction), rich in polyphenolic xanthone glycosides, in concentrations from 5 to 100 µg/mL, and 3-NP in concentrations from 2.5 to 15 mM, were examined. After 8, 16, 24, 48, and 72 h of exposure of cells to various combinations of 3-NP and XF, the MTT viability assay was performed and morphological changes were estimated by confocal fluorescence microscopy. The obtained results showed a significant increase in the number of cells surviving after treatment with XF with exposure to neurotoxic 3-NP and decreased morphological changes in PC12 cells in a dose and time dependent manner. The most effective protective action was observed when PC12 cells were pre-incubated with the XF. This effect may contribute to the traditional indications of this herb for neurological and cognitive complaints. However, a significant cytotoxicity observed at higher XF concentrations (over 10 µg/mL) and longer incubation time (48 h) requires caution in future research and thorough investigation into potential adverse effects.


Subject(s)
Anemarrhena/chemistry , Neuroprotective Agents/pharmacology , Nitro Compounds/adverse effects , PC12 Cells/cytology , Propionates/adverse effects , Xanthones/pharmacology , Animals , Apoptosis/drug effects , Dose-Response Relationship, Drug , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/pharmacology , Molecular Structure , Neuroprotective Agents/chemistry , PC12 Cells/drug effects , Rats , Rhizome/chemistry , Time Factors , Xanthones/chemistry
2.
Article in English | MEDLINE | ID: mdl-32071052

ABSTRACT

This study was conducted in treatment-naive adults with drug-susceptible pulmonary tuberculosis in Port-au-Prince, Haiti, to assess the safety, bactericidal activity, and pharmacokinetics of nitazoxanide (NTZ). This was a prospective phase II clinical trial in 30 adults with pulmonary tuberculosis. Twenty participants received 1 g of NTZ orally twice daily for 14 days. A control group of 10 participants received standard therapy over 14 days. The primary outcome was the change in time to culture positivity (TTP) in an automated liquid culture system. The most common adverse events seen in the NTZ group were gastrointestinal complaints and headache. The mean change in TTP in sputum over 14 days in the NTZ group was 3.2 h ± 22.6 h and was not statistically significant (P = 0.56). The mean change in TTP in the standard therapy group was significantly increased, at 134 h ± 45.2 h (P < 0.0001). The mean NTZ MIC for Mycobacterium tuberculosis isolates was 12.3 µg/ml; the mean NTZ maximum concentration (Cmax) in plasma was 10.2 µg/ml. Negligible NTZ levels were measured in sputum. At the doses used, NTZ did not show bactericidal activity against M. tuberculosis Plasma concentrations of NTZ were below the MIC, and its negligible accumulation in pulmonary sites may explain the lack of bactericidal activity. (This study has been registered at ClinicalTrials.gov under identifier NCT02684240.).


Subject(s)
Antitubercular Agents/pharmacokinetics , Antitubercular Agents/therapeutic use , Mycobacterium tuberculosis/drug effects , Nitro Compounds/pharmacokinetics , Nitro Compounds/therapeutic use , Thiazoles/pharmacokinetics , Thiazoles/therapeutic use , Tuberculosis, Pulmonary/drug therapy , Adult , Antitubercular Agents/adverse effects , Female , Haiti , Humans , Male , Microbial Sensitivity Tests , Nitro Compounds/adverse effects , Sputum/microbiology , Thiazoles/adverse effects , Young Adult
3.
Sci Rep ; 9(1): 13770, 2019 09 24.
Article in English | MEDLINE | ID: mdl-31551470

ABSTRACT

Pesticide use is one of the main causes of pollinator declines in agricultural ecosystems. Traditionally, most laboratory studies on bee ecotoxicology test acute exposure to single compounds. However, under field conditions, bees are often chronically exposed to a variety of chemicals, with potential synergistic effects. We studied the effects of field-realistic concentrations of three pesticides measured in pollen and nectar of commercial melon fields on the solitary bee Osmia bicornis L. We orally exposed females of this species throughout their life span to 8 treatments combining two neonicotinoid insecticides (acetamiprid, imidacloprid) and a triazole fungicide (myclobutanil) via pollen and sugar syrup. We measured pollen and syrup consumption, longevity, ovary maturation and thermogenesis. Pesticide intake was three orders of magnitude higher via syrup than pollen. At the tested concentrations, no synergistic effects emerged, and we found no effects on longevity and ovary maturation. However, all treatments containing imidacloprid resulted in suppressed syrup consumption and drastic decreases in thoracic temperature and bee activity. Our results have important implications for pesticide regulation. If we had measured only lethal effects we would have wrongly concluded that the pesticide combinations containing imidacloprid were safe to O. bicornis. The incorporation of tests specifically intended to detect sublethal effects in bee risk assessment schemes should be an urgent priority. In this way, the effects of pesticide exposure on the dynamics of bee populations in agroecosystems will be better assessed.


Subject(s)
Bees/drug effects , Bees/physiology , Pesticides/adverse effects , Plant Nectar/administration & dosage , Pollen/metabolism , Animal Feed , Animals , Ecosystem , Female , Neonicotinoids/adverse effects , Nitro Compounds/adverse effects , Pollination/drug effects , Thiazoles/adverse effects
4.
Proc Biol Sci ; 285(1883)2018 07 25.
Article in English | MEDLINE | ID: mdl-30051863

ABSTRACT

Widespread use of neonicotinoid insecticides, such as imidacloprid, is often associated with diminishing populations of bees; this loss of pollinators presents a concern for food security and may cause unpredictable changes in ecological networks. However, little is known about the potential behavioural mechanisms behind the neonicotinoid-associated pollinator decline. We quantified the effects of low-dose (1 ppb) imidacloprid exposure on the foraging behaviour of bumblebees (Bombus terrestris). Individual bumblebees were released into a flight arena containing three patches of robotic flowers whose colour (yellow, orange, blue) indicated whether the flower delivered a reward (sugar solution). Exposure to imidacloprid had no significant effect on measures of bumblebee physical performance (such as flight speed) or learning (identifying rewarding flowers). However, pesticide-treated bumblebees had reduced foraging motivation compared with the control bumblebees, as they visited fewer robotic flowers, were slower to start foraging and did not visit all three flower colours as often. Neonicotinoid concentrations of 1 ppb, often reported in plant nectar near agricultural lands, can thus affect the foraging behaviour of bumblebees. Even without a notable impact on flight performance and learning, a reduction in foraging motivation could explain the poor performance of colonies of bumblebees exposed to neonicotinoids.


Subject(s)
Bees/drug effects , Insecticides/adverse effects , Neonicotinoids/adverse effects , Nitro Compounds/adverse effects , Plant Nectar/chemistry , Pollen/chemistry , Animals , Bees/physiology , Dose-Response Relationship, Drug , Feeding Behavior/drug effects , Learning , Motivation/drug effects
5.
Proc Biol Sci ; 285(1880)2018 06 13.
Article in English | MEDLINE | ID: mdl-29899072

ABSTRACT

Bumblebees are among the world's most important groups of pollinating insects in natural and agricultural ecosystems. Each spring, queen bumblebees emerge from overwintering and initiate new nests, which ultimately give rise to workers and new reproductives later in the season. Nest initiation and survival are thus key drivers of both bumblebee pollination services and population dynamics. We performed the first laboratory experiment with the model bumblebee species Bombus impatiens that explores how early nesting success is impacted by the effects of temporary or more sustained exposure to sublethal levels of a neonicotinoid-type insecticide (imidacloprid at 5 ppb in nectar) and by reliance on a monofloral pollen diet, two factors that have been previously implicated in bumblebee decline. We found that queens exhibited increased mortality and dramatically reduced activity levels when exposed to imidacloprid, as well as delayed nest initiation and lower brood numbers in the nest, but partially recovered from these effects when they only received early, temporary exposure. The effects of pollen diet on individual queen- and colony-level responses were overshadowed by effects of the insecticide, although a monofloral pollen diet alone was sufficient to negatively impact brood production. These findings speak to the sensitivity of queen bumblebees during the nest initiation phase of the colony cycle, with implications for how queens and their young nests are uniquely impacted by exposure to threats such as pesticide exposure and foraging habitat unsuitability.


Subject(s)
Bees/physiology , Insecticides/adverse effects , Neonicotinoids/adverse effects , Nesting Behavior/drug effects , Nitro Compounds/adverse effects , Pollen/adverse effects , Animals , Bees/drug effects , Diet/adverse effects
6.
J Toxicol Environ Health A ; 81(8): 229-239, 2018.
Article in English | MEDLINE | ID: mdl-29437547

ABSTRACT

Imidacloprid (IMD) is a neonicotinoid insecticide widely used in crops, pets, and on farm animals for pest control. Several studies were conducted examining the adverse effects of IMD on animals often exhibiting hepatic damage. The aim of this study was to determine the effects of IMD on bioenergetics of mitochondria isolated from rat liver. Imidacloprid (50-200 µM) produced a concentration-dependent decrease in oxygen consumption and ATP production without markedly affecting mitochondrial membrane potential (MMP). Oxygen consumption experiments showed that IMD did not significantly affect the respiratory chain, and this was similar to findings with oligomycin and carboxyatractyloside, suggesting a direct action on FoF1-ATP synthase and/or the adenine nucleotide translocator (ANT). Imidacloprid inhibited FoF1-ATP synthase activity only in disrupted mitochondria and induced a partial inhibition of ADP-stimulated depolarization of the MMP. Our results indicate that IMD interacts specifically with FoF1-ATP synthase resulting in functional inhibition of the enzyme with consequent impairment of mitochondrial bioenergetics. These effects of IMD on mitochondrial bioenergetics may be related to adverse effects of this insecticide on the liver.


Subject(s)
Energy Metabolism/drug effects , Insecticides/adverse effects , Liver/drug effects , Mitochondria/drug effects , Neonicotinoids/adverse effects , Nitro Compounds/adverse effects , Proton-Translocating ATPases/metabolism , Animals , Liver/enzymology , Male , Mitochondria/enzymology , Rats , Rats, Wistar
7.
Sci Rep ; 7(1): 15562, 2017 Nov 14.
Article in English | MEDLINE | ID: mdl-29138404

ABSTRACT

Neonicotinoid pesticides have been linked to global declines of beneficial insects such as bumblebees. Exposure to trace levels of these chemicals causes sub-lethal effects, such as reduced learning and foraging efficiency. Complex behaviours may be particularly vulnerable to the neurotoxic effects of neonicotinoids. Such behaviours may include buzz pollination (sonication), in which pollinators, usually bees, use innate and learned behaviours to generate high-frequency vibrations to release pollen from flowers with specialised anther morphologies. This study assesses the effect of field-realistic, chronic exposure to the widely-used neonicotinoid thiamethoxam on the development of sonication buzz characteristics over time, as well as the collection of pollen from buzz-pollinated flowers. We found that the pollen collection of exposed bees improved less with increasing experience than that of unexposed bees, with exposed bees collecting between 47% and 56% less pollen by the end of 10 trials. We also found evidence of two distinct strategies for maximising pollen collection: (1) extensions to the duration of individual buzzes and (2) extensions of the overall time spent buzzing. We find new complexities in buzz pollination, and conclude that the impacts of field-realistic exposure to a neonicotinoid pesticide may seriously compromise this important ecosystem service.


Subject(s)
Bees/drug effects , Neonicotinoids/adverse effects , Pesticides/adverse effects , Pollination/drug effects , Animals , Behavior, Animal/drug effects , Flowers/drug effects , Flowers/growth & development , Nitro Compounds/adverse effects , Pollen/drug effects
8.
Biomed Pharmacother ; 91: 1022-1041, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28531918

ABSTRACT

Imidacloprid (IMI) is very harmful to human health and cause problems. Recently, plants have been considered as potential agents for protection against these disorders. Urtica urens L. (UU) is very useful for relieving rheumatic pains and there is no scientific evidence justifying its use, which lets us think of its direct effect on the bone. This study aimed to investigate the protective effect of UU against toxicity effects of IMI in female rat. Rats were divided into control group, 3 groups treated with IMI at 50, 200 or 300mg/kg/day and 3 groups co-treated with IMI (50, 200 or 300mg/kg/day)+100mg/kg/day of UU. We studied bone remodeling through histological, histomorphometry and biochemical analyses. In IMI- treated groups, we have noted, following histomorphomotric analysis, significant decreases in cortical, trabecular thicknesses and osteoid surfaces. Elsewhere, IMI intoxication significantly decreased serum vitamin D and hydroxyproline levels in the groups treated for 60days. IMI intoxication increased significantly calcium, phosphorus contents, MDA and AOPP levels and the rate of calcification. It decreased significantly GSH, GPx, SOD, CAT, 17b-Estradiol and vitamin E levels, induces a tendency of rarefaction and increases of intrabecular spaces. The co-treatment with UU improved all biochemical parameters (hydroxyproline, MDA, AOPP, GSH, GPx, SOD, CAT, 17b-Estradiol, vitamin D, vitamin E calcium, phosphorus). UU leads to a significant increase in cortical, trabecular thicknesses, osteoid surfaces, a decrease in the intrabecular spaces and the rarefaction of bone. In conclusion, IMI inhibits bone remodeling and enhances bone formation. A significant antioxidant activity was also observed in UU and a total of 6 compounds were identified. Co-administration of UU provided a significant protection which might be due to its antioxidant property.


Subject(s)
Bone Remodeling/drug effects , Ethanol/chemistry , Neonicotinoids/adverse effects , Nitro Compounds/adverse effects , Plant Extracts/pharmacology , Protective Agents/pharmacology , Urticaceae/chemistry , Animals , Antioxidants/metabolism , Bone and Bones/drug effects , Bone and Bones/metabolism , Calcium/metabolism , Estradiol/metabolism , Female , Hydroxyproline/blood , Malondialdehyde/metabolism , Oxidative Stress/drug effects , Phosphorus/metabolism , Rats , Vitamin D/blood , Vitamin E/blood
9.
Biochim Biophys Acta ; 1853(10 Pt A): 2306-25, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25986861

ABSTRACT

Oncostatin M (OSM), a cytokine in the interleukin-6 (IL-6) family, has been proposed to play a protective role in the central nervous system, such as attenuation of excitotoxicity induced by N-methyl-D-aspartate (NMDA) and glutamate. However, the potential neuroprotective effects of OSM against mitochondrial dysfunction have never been reported. In the present study, we tested the hypothesis that OSM may confer neuronal resistance against 3-nitropropionic acid (3-NP), a plant toxin that irreversibly inhibits the complex II of the mitochondrial electron transport chain, and characterized the underlying molecular mechanisms. We found that OSM preconditioning dose- and time-dependently protected cortical neurons against 3-NP toxicity. OSM stimulated expression of myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic Bcl-2 family member expressed in differentiating myeloid cells, that required prior phosphorylation of Janus kinase-1 (JAK1), JAK2, extracellular signal-regulated kinase-1/2 (ERK1/2), signal transducer and activator of transcription-3 (STAT3), STAT1, and cAMP-response element-binding protein (CREB). Pharmacological inhibitors of JAK1, JAK2, ERK1/2, STAT3, STAT1, and CREB as well as the siRNA targeting at STAT3 and Mcl-1 all abolished OSM-dependent 3-NP resistance. Finally, OSM-dependent Mcl-1 induction contributed to the enhancements of mitochondrial bioenergetics including increases in spare respiratory capacity and ATP production. In conclusion, our findings indicated that OSM induces Mcl-1 expression via activation of ERK1/2, JAK1/2, STAT1/3, and CREB; furthermore, OSM-mediated Mcl-1 induction contributes to bioenergetic improvements and neuroprotective effects against 3-NP toxicity in cortical neurons. OSM may thus serve as a novel neuroprotective agent against mitochondrial dysfunction commonly associated with pathogenic mechanisms underlying neurodegeneration.


Subject(s)
Cerebral Cortex/metabolism , Cyclic AMP Response Element-Binding Protein/metabolism , Energy Metabolism/physiology , Janus Kinase 1/metabolism , Janus Kinase 2/metabolism , Mitochondria/metabolism , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Neurons/metabolism , Oncostatin M/metabolism , STAT1 Transcription Factor/metabolism , STAT3 Transcription Factor/metabolism , Animals , Antihypertensive Agents/adverse effects , Antihypertensive Agents/pharmacology , Cerebral Cortex/cytology , Energy Metabolism/drug effects , Myeloid Cell Leukemia Sequence 1 Protein/genetics , Neurons/cytology , Nitro Compounds/adverse effects , Nitro Compounds/pharmacology , Propionates/adverse effects , Propionates/pharmacology , Rats
10.
Nature ; 521(7550): 74-76, 2015 May 07.
Article in English | MEDLINE | ID: mdl-25901684

ABSTRACT

The impact of neonicotinoid insecticides on insect pollinators is highly controversial. Sublethal concentrations alter the behaviour of social bees and reduce survival of entire colonies. However, critics argue that the reported negative effects only arise from neonicotinoid concentrations that are greater than those found in the nectar and pollen of pesticide-treated plants. Furthermore, it has been suggested that bees could choose to forage on other available flowers and hence avoid or dilute exposure. Here, using a two-choice feeding assay, we show that the honeybee, Apis mellifera, and the buff-tailed bumblebee, Bombus terrestris, do not avoid nectar-relevant concentrations of three of the most commonly used neonicotinoids, imidacloprid (IMD), thiamethoxam (TMX), and clothianidin (CLO), in food. Moreover, bees of both species prefer to eat more of sucrose solutions laced with IMD or TMX than sucrose alone. Stimulation with IMD, TMX and CLO neither elicited spiking responses from gustatory neurons in the bees' mouthparts, nor inhibited the responses of sucrose-sensitive neurons. Our data indicate that bees cannot taste neonicotinoids and are not repelled by them. Instead, bees preferred solutions containing IMD or TMX, even though the consumption of these pesticides caused them to eat less food overall. This work shows that bees cannot control their exposure to neonicotinoids in food and implies that treating flowering crops with IMD and TMX presents a sizeable hazard to foraging bees.


Subject(s)
Bees/physiology , Diet/veterinary , Food Preferences , Insecticides/analysis , Plant Nectar/chemistry , Animals , Bees/drug effects , Chemoreceptor Cells/drug effects , Chemoreceptor Cells/metabolism , Female , Flowers/chemistry , Flowers/drug effects , Food Preferences/drug effects , Guanidines/adverse effects , Guanidines/analysis , Guanidines/pharmacology , Imidazoles/adverse effects , Imidazoles/analysis , Imidazoles/pharmacology , Insecticides/adverse effects , Insecticides/pharmacology , Male , Neonicotinoids , Nitro Compounds/adverse effects , Nitro Compounds/analysis , Nitro Compounds/pharmacology , Oxazines/adverse effects , Oxazines/analysis , Oxazines/pharmacology , Pollen/chemistry , Pollination , Reproduction/drug effects , Reproduction/physiology , Survival Analysis , Taste/physiology , Thiamethoxam , Thiazoles/adverse effects , Thiazoles/analysis , Thiazoles/pharmacology
11.
Zhongguo Zhong Yao Za Zhi ; 40(18): 3538-42, 2015 Sep.
Article in Chinese | MEDLINE | ID: mdl-26983196

ABSTRACT

The paper is aimed to establish a method of residue analysis for thiamethoxam and to study its degradation dynamic and final residue and its standard of safe application of thiamethoxam on Lonicera japonica. Samples extracted with methanol by ultrasonication were purified with dichloromethane by liquid-liquid extraction and SPE column and analysed by HPLC-UV. The results showed that average rate was 84.91%-94.44% and RSD 1.74%-4.96% with addition of thiamethoxam in respectively diverse concentration, which meets inspection requirement of pesticide residue. Two kinds of dosages of thiamethoxam were treated- varying from recommended dosage (90 g x hm(-2)) to high dosage (135 g x hm(-2)), Results of two years test showed that thiamethoxam was degraded more than 90% seven days after application and the half - life period of thiamethoxam was 1.54-1.66 d. The digestion rate of thiamethoxam was fast in the L. japonica. The recommended MRL of thiamethoxam in the L. japonica is 0.1 mg x kg(-1), the dosage of 25% thiamethoxam WDG from 90-135 g x hm(-2) is sprayed less than three times a year on L. japonica and 14 days is proposed for the safety interval of the last pesticide application's and harvest's date.


Subject(s)
Agriculture/standards , Insect Control/standards , Insecticides/chemistry , Lonicera/chemistry , Nitro Compounds/chemistry , Oxazines/chemistry , Pesticide Residues/chemistry , Plant Diseases/prevention & control , Thiazoles/chemistry , Agriculture/methods , Chromatography, High Pressure Liquid , Flowers/chemistry , Flowers/growth & development , Flowers/parasitology , Half-Life , Insect Control/methods , Insecticides/adverse effects , Lonicera/growth & development , Lonicera/parasitology , Neonicotinoids , Nitro Compounds/adverse effects , Oxazines/adverse effects , Pesticide Residues/adverse effects , Plant Diseases/parasitology , Thiamethoxam , Thiazoles/adverse effects
12.
Appl Physiol Nutr Metab ; 39(4): 487-96, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24669991

ABSTRACT

The beneficial effects of fish oil (FO) supplements on the central nervous system have been adequately demonstrated. However, FO supplementation at higher doses for longer duration is likely to cause oxidative stress in vivo. To overcome this, attempts have been made to enrich FO with known antioxidants/phytochemicals. In the present study, we examined the hypothesis that a combination of FO with ferulic acid (FA), a naturally occurring phenolic compound, is likely to provide higher degree of neuroprotection. This was examined by employing 3-nitropropionic acid (NPA), a well-known neurotoxin used to mimic behavioural and neurochemical features of Huntington's disease. Growing male rats administered with NPA (25 mg/kg of body weight (bw) for 4 days) were provided with either FO (2 mL/kg bw), FA (50 mg/kg bw) or FO+FA for 2 weeks. Interestingly, FO+FA not only offered significant protection against NPA-induced behavioural impairments, but also markedly attenuated oxidative stress in brain regions (striatum/cerebellum) as evidenced by the reduction in reactive species, malondialdehyde, hydroperoxides and nitric oxide (NO) levels. Further, FO+FA combination restored the activities of various antioxidant enzymes and the levels of cytosolic calcium. In striatum, activity levels of acetylcholinesterase enzyme and dopamine levels were markedly restored among FO+FA rats. Interestingly, NPA-induced mitochondrial dysfunctions were also attenuated among FO+FA rats. Collectively, our findings suggest the advantage of co-treatment of FO with known antioxidants to achieve a higher therapeutic benefit in the treatment of oxidative stress-mediated neurodegenerative conditions.


Subject(s)
Antioxidants/therapeutic use , Coumaric Acids/therapeutic use , Fish Oils/therapeutic use , Neuroprotective Agents/therapeutic use , Neurotoxicity Syndromes/etiology , Neurotoxicity Syndromes/prevention & control , Nitro Compounds/adverse effects , Oxidative Stress/drug effects , Propionates/adverse effects , Animals , Behavior, Animal/drug effects , Energy Metabolism/drug effects , Male , Rats , Rats, Wistar
13.
J Med Food ; 16(10): 934-43, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24138168

ABSTRACT

3-Nitropropionic acid (3-NP) induces cellular energy deficit and oxidative stress-related neurotoxicity via an irreversible inhibition of mitochondrial complex II enzyme, succinate dehydrogenase. Huntington's disease (HD) is a neurological disorder characterized by cognitive and motor dysfunctions. Lutein is a well-known antioxidant used in the management of oxidative stress related diseases. Clinical trials have supported the beneficial effect of lutein in Alzheimer's disease. The present study was designed to explore possible neuroprotective effects of lutein on 3-NP-induced mitochondrial dysfunction and oxidative stress. Systemic administration of 3-NP (25 mg/kg intraperitoneally [i.p.] for 4 consecutive days) caused loss of body weight and neurobehavioral deficits by hind-limb impairment (Narrow Beam test), motor coordination (locomotor activity) and memory dysfunction (Morris water maze and Elevated Plus maze performance). Biochemical analysis revealed significant increase in lipid peroxidation, nitrite concentration, reduced gutathione levels, and acetyl cholinesterase levels and depleted catalase activities in rat brain. The activities of mitochondrial complexes (I, II, IV, and MTT assay) were found to be significantly lowered in brain mitochondria. Daily lutein (50 or 100 mg/kg orally [p.o.]) administration for 14 days significantly improved body weight, neurobehavioral alterations and attenuated oxidative stress and improved mitochondrial enzymes complex activities of rat brain. Histopathological examination further affirmed the neuroprotective effect of lutein on 3-NP induced pathological lesions. The present study indicates that lutein is a promising candidate for the management of HD and related conditions.


Subject(s)
Huntington Disease/drug therapy , Lutein/administration & dosage , Neuroprotective Agents/administration & dosage , Nitro Compounds/adverse effects , Propionates/adverse effects , Animals , Brain/drug effects , Brain/metabolism , Female , Glutathione/metabolism , Humans , Huntington Disease/chemically induced , Huntington Disease/metabolism , Huntington Disease/psychology , Lipid Peroxidation , Maze Learning/drug effects , Memory/drug effects , Motor Activity/drug effects , Rats , Rats, Sprague-Dawley
14.
Article in English | MEDLINE | ID: mdl-23906092

ABSTRACT

The dissipation behaviour of three neonicotinoids - thiamethoxam, imidacloprid and acetamiprid - was compared in tea shoots, in Chinese green and black tea, and after tea infusion in hot water. The simple and rapid analytical procedures for the quantification of these three residues in these matrices were developed using HPLC with ultraviolet (UV) detection. Degradation rates in tea shoots of neonicotinoids applied in either recommended or double dosages followed first-order kinetics, with half-lives of 1.62 or 1.58 days for thiamethoxam, of 2.45 or 2.67 days for imidacloprid, and of 3.24 or 3.85 days for acetamiprid, respectively. Through harvest and processing the residue retentions for thiamethoxam, imidacloprid and acetamiprid were 85.0%, 84.1% and 70.6% of the initial dosages in green tea, and 77.1%, 52.4% and 57.4% in black tea. These three residues all showed high transfer rates through green or black tea brewing of 80.5% or 81.6% for thiamethoxam, of 63.1% or 62.2% for imidacloprid, and of 78.3% or 80.6% for acetamiprid. Waiting periods between the last application and harvest of at least 12, 17 and 20 days were suggested for thiamethoxam, imidacloprid and acetamiprid, respectively, after application at their recommend dosages to ensure levels below a maximum residue limit (MRL) of 0.05 mg kg(-1).


Subject(s)
Food Contamination/analysis , Insecticides/analysis , Tea/chemistry , Camellia sinensis/adverse effects , Camellia sinensis/chemistry , China , Food Handling , Humans , Imidazoles/adverse effects , Imidazoles/analysis , Insecticides/adverse effects , Neonicotinoids , Nitro Compounds/adverse effects , Nitro Compounds/analysis , Oxazines/adverse effects , Oxazines/analysis , Pesticide Residues/adverse effects , Pesticide Residues/analysis , Pyridines/adverse effects , Pyridines/analysis , Tea/adverse effects , Thiamethoxam , Thiazoles/adverse effects , Thiazoles/analysis
15.
Phytother Res ; 24(6): 885-92, 2010 Jun.
Article in English | MEDLINE | ID: mdl-19943239

ABSTRACT

While the usage of Centella asiatica (CA) is on the increase worldwide, evidence demonstrating its protective efficacy against neurotoxicants is scarce. Hence the present study aimed to understand the neuroprotective efficacy of a standardized aqueous extract of CA against 3-nitropropionic-acid(3-NPA)-induced oxidative stress in the brain of prepubertal mice. We assessed the degree of oxidative stress in cytoplasm of brain regions of male mice (4 wk- old) given CA prophylaxis (5 mg/kg bw) for 10 days followed by 3-NPA administration (i.p.75 mg/kg bw) on the last 2 days. The neurotoxicant elicited marked oxidative stress in the brain of untreated mice as evident by enhanced malondialdehyde levels, reactive oxygen species (ROS) generation, hydroperoxides and protein carbonyls (a measure of protein oxidation) in striatum and other regions (cortex, cerebellum and hippocampus), while CA prophylaxis completely ameliorated the 3-NPA- induced oxidative stress. Depletion of glutathione (GSH) levels, total thiols, perturbations in antioxidant enzymes and cholinergic enzymes in brain discernible among 3-NPA-treated mice were predominantly restored to normalcy with CA prophylaxis. It is hypothesized that the prophylactic protection offered by CA extract against neurotoxicant exposure may be largely due to its ability to enhance GSH, thiols and antioxidant defenses in the brain of prepubertal mice.


Subject(s)
Antioxidants/pharmacology , Brain/drug effects , Centella/chemistry , Nitro Compounds/adverse effects , Oxidative Stress/drug effects , Plant Extracts/pharmacology , Propionates/adverse effects , Animals , Brain/pathology , Lipid Peroxidation , Male , Malondialdehyde/metabolism , Mice , Reactive Oxygen Species/metabolism
16.
Phytomedicine ; 15(11): 971-84, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18539017

ABSTRACT

Centella asiatica (CA) is a common medicinal plant used in the ayurvedic system of medicine to treat various ailments and as a memory enhancer. Despite its extensive usage in children, data on its ability to modulate neuronal oxidative stress in prepubertal rodents are limited. Hence in the present study we have addressed primarily two questions (i) whether dietary intake of CA leaf powder possess the propensity to modulate endogenous oxidative markers in mouse brain regions and (ii) the efficacy of CA aqueous extract to abrogate 3-nitropropionic acid (3-NPA)-induced oxidative stress in brain mitochondria in vitro. Prepubertal male mice were fed CA-incorporated diet (0.5 and 1%) for 4 weeks, and biochemical markers of oxidative stress in brain regions were determined. Mice fed CA showed significant diminution in the levels of malondialdehyde (30-50%), reactive oxygen species (32-42%) and hydroperoxide levels (30-35%), which was accompanied by enhanced activities of antioxidant enzymes in all brain regions. While the levels of reduced glutathione and total thiols were elevated, the protein carbonyl content was decreased in brain among CA-fed mice. Interestingly, the oxidative markers among brain mitochondria of CA-fed mice were also significantly diminished (malondialdehyde, 25%; ROS, 30%; hydroperoxides, 35% and protein carbonyls, 28%). Further, the aqueous extract of CA showed significant free radical scavenging activity determined in established chemical test systems (viz., DPPH, superoxide and hydroxyl radical scavenging activity). Furthermore, the aqueous extract of CA markedly ameliorated the 3-NPA induced oxidative stress response in brain mitochondria under in vitro exposure,. Taken together, these data suggest that CA has the propensity to modulate both endogenous and neurotoxicant induced oxidative impairments in the brain and may be effectively employed as a neuroprotective adjuvant to abrogate oxidative stress in vivo.


Subject(s)
Brain/drug effects , Brain/metabolism , Centella , Mitochondria/drug effects , Oxidative Stress/drug effects , Triterpenes/pharmacology , Animals , Antioxidants/metabolism , Biomarkers/metabolism , Enzymes/metabolism , Glutathione/metabolism , Hydrogen Peroxide/metabolism , Male , Malondialdehyde/metabolism , Mice , Mitochondria/metabolism , Nitro Compounds/adverse effects , Plant Extracts , Plant Leaves , Plants, Medicinal , Propionates/adverse effects , Protein Carbonylation/drug effects , Puberty , Reactive Oxygen Species/metabolism
17.
Commun Agric Appl Biol Sci ; 70(4): 569-79, 2005.
Article in English | MEDLINE | ID: mdl-16628891

ABSTRACT

Thiamethoxam, mainly sold under the trademark of Actara, is a neonicotinoid widely used in covered vegetables for the control of aphids and whiteflies. In these crops, and particularly in covered tomatoes, bumble-bees are used for cross-pollination as an alternative to labour intensive manual techniques. In this study, made on tomatoes grown in separated greenhouse plots in Murcia, Southern Spain, thiamethoxam was applied through drip irrigation at a rate of 200 g ai/ha, and as a split application of the same rate, to evaluate the effects on pollinating bumble bees compared to a foliar application of a toxic standard. The results showed that the toxic foliar standard had a clear effect on the pollination of tomato flowers, declining to zero pollination two weeks after application, whereas both the single and split drip irrigation applications of Actara had no effect on pollination when compared to the control plots. The count of dead adults and larvae did not show any differences between the treatments, whereas the measurement of sugar water consumption was shown to correlate well with pollination. The consumption of sugar water declined in the toxic standard plots by 69% with respect to the control, whilst the decline in lower dose drip irrigation application was only 3%. In regard to hive weight, and number of adults and brood after destructive sampling; there were no statistical differences between the treatments but a negative effect of the foliar treatment was observed. Based on these results we can conclude that a split application of Actara applied in drip irrigation to the soil/substrate has no effect on the bumble-bees used in tomatoes for pollination.


Subject(s)
Agriculture/methods , Bees/growth & development , Insecticides/adverse effects , Nitro Compounds/adverse effects , Oxazines/adverse effects , Solanum lycopersicum/parasitology , Animals , Bees/drug effects , Bees/physiology , Dose-Response Relationship, Drug , Solanum lycopersicum/growth & development , Neonicotinoids , Pollen/physiology , Safety , Seasons , Thiamethoxam , Thiazoles
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