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Journal ArticleDOI

Histopathological Changes In The Motor Cortex Of Rat CNS After Pyrethroid Based Mosquito Repellent Inhalation An Experimental Study

30 Aug 2015-International journal of biomedical research-Vol. 6, Iss: 8, pp 559-562

TL;DR: It is established that pyrethroids given by inhalational route do cause neurotoxicity on chronic exposure as shown by inflammatory and degenerative changes in the histological sections of CNS.

AbstractIntroduction: The liquid vaporizers are very commonly used as residential insecticides in developing countries. Neurotoxic effects of pyrethroids have been reported earlier but studies regarding their histopathological effects on motor cortex area of cerebrum are rare. So the present study was planned  to assess and compare the effects of pyrethroid based mosquito repellent inhalation in the motor cortex of  rat CNS. Method: Twenty albino rats were divided into two groups of control and experimental. Rats in experimental group were exposed to 3.2% w/v prallethrin vapours 12 hours daily for 180 days. Control animals were kept under identical conditions without exposure to said repellent. The animals were sacrificed after 180 days. Their Cerebrum removed and  processed. Sections cut and stained with Haematoxylin,Eosin and thionin . Result: Neurohistological alteration in our study in experimental rats were, loss of organisation of the cortical  layer, increased density of inflammatory cells and initial signs of neuronal damage when compared to control ones Conclusion: The findings of our study establish that pyrethroids given by inhalational route do cause neurotoxicity on chronic exposure as shown by inflammatory and degenerative changes in the histological sections of CNS.

Topics: Prallethrin (53%)

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Citations
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Journal ArticleDOI
TL;DR: There is oxidative stress in Wistar rats exposed to pyrethroids based insecticides and lowered antioxidant defenses also observed in the studied population and there was increased in weight differences with possibility of becoming obese.
Abstract: Indiscriminate use of pesticides appears to increase the production of free radicals in organisms such as humans and other animals. Thus, the aim of this study was to investigate the effect of pyrethroid insecticides on oxidative stress biomarkers and atherogenic indices in exposed adult Wistar rats. A total number of apparently healthy 60 Wistar rats were randomly selected for this study and divided into two groups. Thirty six (36) were exposed to 1.2 % w/v pyrethroid insecticides while the remaining twenty four (24) were grouped as non-exposed. The animals in each group were anesthetized and blood sample was collected from the inferior vena cava after days of exposure. Plasma levels of total antioxidant status (TAS), malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), Nitric Oxide (NO) and lipids profiles were determined using standard spectrophotometric techniques. Plasma activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were determined using standard spectrophotometric techniques. Statistical analysis of data was obtained and P<0.05 was considered significant. The mean TChol and HDL were significantly higher in 7days than 41days exposure, while plasma mean TChol and HDL were significantly lower in 41days than 21days exposure. The plasma mean levels of SOD, GPx, CAT, GSH and TAS were significantly decreasing while plasma mean levels of MDA, H2O2 and NO were significantly increasing from 7 days through 41 days exposure in exposed groups irrespective of the gender. In conclusion, this study observed that there is oxidative stress in Wistar rats exposed to pyrethroids based insecticides and lowered antioxidant defenses also observed in the studied population. Also, there was increased in weight differences with possibility of becoming obese. Thus, antioxidant supplements are advised as a prophylactic supportive therapy for adequate measures in preventing development of oxidative stress-associated complications among exposed individuals.

4 citations


Journal ArticleDOI
TL;DR: It is observed that pyrethroids can cause oxidative stress, deplete antioxidant levels, nephrotoxicity, and may modulate both humoral and cellular immune functions, and established NGAL as a sensitive diagnostic tool and early biomarker for acute kidney injury (AKI).
Abstract: BACKGROUND: Insecticide usage has increased in the tropics and subtropics due to the high prevalence of vector-borne infections, even though insecticide use effectively reduces insect-borne diseases. Insecticide exposure can cause oxidative stress and have severe consequences for human health. The study was then designed to evaluate oxidative stress and its effects on immunomodulatory and renal integrity among Wistar rats exposed to pyrethroids. METHODS: Eighty-four Wistar rats were randomly selected and divided into two groups. Fifty-one rats were exposed to 1.2 %w/v pyrethroids, while the remaining thirty-three rats were grouped as non-exposed. The groups were divided into three different groups, each with 7, 21, and 41 days. After days of exposure, the animals in each group were anesthetized, and blood samples were collected from the inferior vena cava. Using standard spectrophotometric techniques, the levels of total antioxidant status (TAS), malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), urea, creatinine and uric acid were determined. Blood activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) were determined. ELISA was used to determine levels of IgG, IgA, IgE, TNF-α, and NGAL. Data obtained were statistically compared. RESULTS: The serum mean levels of SOD, GPx, CAT, GSH, and TAS were significantly reduced (p < 0.05) while mean levels of MDA, H2O2, IgG, IgE, IgA, TNFα, neutrophil gelatinase-associated lipocalin (NGAL), urea, uric acid, and creatinine were significantly elevated (p < 0.05) from 7 to 41 days exposure in exposed groups. NGAL had a higher area under the ROC curve than urea and creatinine. CONCLUSIONS: This study observed that pyrethroids can cause oxidative stress, deplete antioxidant levels, nephrotoxicity, and may modulate both humoral and cellular immune functions. It also established NGAL as a sensitive diagnostic tool and early biomarker for acute kidney injury (AKI).

Journal ArticleDOI
TL;DR: It is self-evident that pyrethroid chemicals exposure may disrupt carbohydrate and lipid metabolism by raising the risk of obesity among the exposed groups.
Abstract: BACKGROUND: Due to widespread use of pesticides, an individual’s lifetime exposure to pesticide mixtures is unavoidable, resulting in potentiation of toxic effects such as changing metabolic signaling temporarily or permanently due to the formation of free radicals among exposed individuals. OBJECTIVE: This study then looked at the expression of leptin and insulin receptors in Wistar rats exposed to pyrethroid and its effects on adipokines and glycemic indices. METHODS: 84 Wistar rats were randomly selected and divided into two groups. 51 rats were exposed to 1.2 % w/v pyrethroid insecticides, while the remaining 33 rats were grouped as non-exposed. The groups were divided into three different groups, each with 7, 21, and 41 days. The animals were anesthetically sacrificed and samples of blood were collected after days of exposure. The levels of total antioxidant status (TAS), malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), nitric oxide (NO), glucose and lipids were determined. Blood activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) were also determined. ELISA was used to assess leptin, adiponectin, insulin, CRP, IL-6, and TNFα. Glycaemic indices were calculated appropriately. Leptin and Insulin expression was determined using the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Data obtained were statistically compared, and P≤0.05 was considered significant. RESULTS: The mean TChol, TAG, and HDL-C were significantly different (p < 0.05) among the exposed groups. The serum mean levels of SOD, GPx, CAT, GSH, TAS, QUICKI, TNFα, IL6, and CRP were significantly reduced (p < 0.05), while mean levels of MDA, H2O2, NO, insulin, HOMA-IR, FIRI, leptin, and adiponectin were significantly elevated (p < 0.05) in exposed groups. The relative expression of insulin and leptin genes in exposed and non-exposed groups was also shown by column. CONCLUSION: It is self-evident that pyrethroid chemicals exposure may disrupt carbohydrate and lipid metabolism by raising the risk of obesity among the exposed groups.

References
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Journal ArticleDOI
TL;DR: Insecticide research, having passed through several Golden Ages, is now in a renaissance of integrating chemicals and biologicals for sustainable pest control with human safety.
Abstract: Insecticide research led to the first "complete" victories in combatting pests almost 50 years ago with the chlorinated hydrocarbons followed quickly by the organophosphates, methylcarbamates, and pyrethroids--all neuroactive chemicals. This Golden Age of Discovery was the source of most of our current insecticides. The challenge then became health and the environment, a Golden Age met with selective and degradable compounds. Next the focus shifted to resistance, novel biochemical targets, and new chemical approaches for pest control. The current Golden Age of Genetic Engineering has curtailed, but is unlikely to eliminate, chemical use on major crops. Insecticide research, having passed through several Golden Ages, is now in a renaissance of integrating chemicals and biologicals for sustainable pest control with human safety.

585 citations


"Histopathological Changes In The Mo..." refers background in this paper

  • ...Their use has risen dramatically during the last 10 years in India and other developing countries due to high insecticidal and low mammalian toxic effects[1,4-7]....

    [...]


Journal ArticleDOI
TL;DR: Comparative sequence analysis of housefly strains carrying kdr or the more potentsuper-kdr factor revealed two amino acid mutations that correlate with these resistance phenotypes, and suggest a binding site for pyrethroids at the intracellular mouth of the channel pore in a region known to be important for channel inactivation.
Abstract: We report the isolation of cDNA clones containing the full 6.3-kb coding sequence of the para-type sodium channel gene of the housefly, Musca domestica. This gene has been implicated as the site of knockdown resistance (kdr), an important resistance mechanism that confers nerve insensitivity to DDT and pyrethroid insecticides. The cDNAs predict a polypeptide of 2108 amino acids with close sequence homology (92% identity) to the Drosophila para sodium channel, and around 50% homology to vertebrate sodium channels, Only one major splice form of the housefly sodium channel was detected, in contrast to the Drosophila para transcript which has been reported to undergo extensive alternative splicing. Comparative sequence analysis of housefly strains carrying kdr or the more potent super-kdr factor revealed two amino acid mutations that correlate with these resistance phenotypes. Both mutations are located in domain II of the sodium channel. A leucine to phenylalanine replacement in the hydro-phobic IIS6 transmembrane segment was found in two independent kdr strains and six super-kdr strains of diverse geographic origin, while an additional methionine to threonine replacement within the intracellular IIS4-S5 loop was found only in the super-kdr strains. Neither mutation was present in five pyrethroid-sensitive strains. The mutations suggest a binding site for pyrethroids at the intracellular mouth of the channel pore in a region known to be important for channel inactivation.

498 citations


Journal ArticleDOI
TL;DR: The results support the idea that membrane ATPases are one target of the neurotoxic effect of pyrethroid compounds.
Abstract: Pyrethroids are used widely as insecticides both in agriculture and in households. A cellular target of pyrethroids is the sodium channel in the membrane. In the present study, the activity of the membrane bound integral protein ATPase was studied as a biomarker for the membrane effect of the pyrethroids permethrin and cypermethrin. Male Sprague-Dawley rats were used for cerebral synaptosome preparation. The isolation of synaptosomes was performed with the Percoll gradient method. Both total ATPase and Mg(2+) activated ATPase were studied by determining inorganic phosphate liberated from the substrate ATP. One hour exposure to permethrin (Biokill) and cypermethrin (Ripcord) insecticide products affected ATPase activities. The activity of Na(+), K(+) ATPase decreased dose-dependently in 10-50 microM concentrations of permethrin, and Mg(2+) activated ATPase increased over twofold in the same concentrations of the active components. The effect of the cypermethrin compound Ripcord was not clearly dose-dependent. The activity of total ATPase was almost entirely lost in the concentrations of 100 microM of permethrin and cypermethrin. The results support the idea that membrane ATPases are one target of the neurotoxic effect of pyrethroid compounds.

99 citations


"Histopathological Changes In The Mo..." refers background in this paper

  • ...Their use has risen dramatically during the last 10 years in India and other developing countries due to high insecticidal and low mammalian toxic effects[1,4-7]....

    [...]


Journal ArticleDOI
TL;DR: Pyrethroid‐based mosquito repellents (MR) are commonly used to protect humans against mosquito vector and the neurotoxicity caused by MR has aroused concern among public regarding their use.
Abstract: Pyrethroid-based mosquito repellents (MR) are commonly used to protect humans against mosquito vector. New born babies and children are often exposed to pyrethroids for long periods by the use of liquid vaporizers. Occupational and experimental studies indicate that pyrethroids can cause clinical, biochemical and neurological changes, and that exposure to pyrethroids during organogenesis and early developmental period is especially harmful. The neurotoxicity caused by MR has aroused concern among public regarding their use. In the present study, the effect of exposure of rat pups during early developmental stages to a pyrethroid-based MR (allethrin, 3.6% w/v, 8h per day through inhalation) on blood-brain barrier (BBB) permeability was investigated. Sodium fluororescein (SF) and Evan's blue (EB) were used as micromolecular and macromolecular tracers, respectively. Exposure during prenatal (gestation days 1-20), postnatal (PND1-30) and perinatal (gestation days 1-20 + PND1-30) periods showed significant increase in the brain uptake index (BUI) of SF by 54% (P < 0.01), 70% (P < 0.01), 79% (P < 0.01), respectively. This increase persisted (68%, P < 0.01) even 1 week after withdrawal of exposure (as assessed on PND37). EB did not exhibit significant change in BBB permeability in any of the group. The results suggest that MR inhalation during early prenatal/postnatal/perinatal life may have adverse effects on infants leading to central nervous system (CNS) abnormalities, if a mechanism operates in humans similar to that in rat pups.

50 citations


"Histopathological Changes In The Mo..." refers background in this paper

  • ...Prallethrin is regularly used with its maximal human exposure for prolonged periods for atleast 8h/day[8] but there is a paucity of information concerning the effect of routine and long term use of the prallethrin based mosquito repellents in humans....

    [...]


Journal ArticleDOI
TL;DR: The data suggests that low level exposure to DT in utero during brain growth spurt period adversely affects the developing brain and the changes persist even up to 12 weeks postnatal period in rats.
Abstract: Effect of low level in utero exposure to deltamethrin (DT) (1mg /kg wt.) during gestation day 14-20 was studied on selected neurobehavioral, neurochemical, immunohistochemical parameters in rats at 6 and 12 weeks postnatal period. The significant increase in acetylcholinesterase activity and decrease in (3)H-quinuclidinyl benzilate binding in the hippocampal region of DT exposed animals, suggesting impairment in cholinergic (muscarinic) receptors. A significant decrease in the learning and memory performances was also observed both at 6 and 12 weeks, which is directly correlated with decrease in muscarinic receptor binding. Immunohistochemistry and image analysis of growth associated protein-43, a neuron specific protein present in axonal growth cone and a marker for neuronal differentiation and synaptogenesis, exhibit aberrant increase in its expression in the hippocampus in DT exposed rats at both time periods. The data suggests that low level exposure to DT in utero during brain growth spurt period adversely affects the developing brain and the changes persist even up to 12 weeks postnatal period in rats. Although there is no significant recovery at 12 weeks assessment but still significant impairment persist on biochemical and behavioural parameters.

45 citations


"Histopathological Changes In The Mo..." refers result in this paper

  • ...There was insult to the nervous tissue by pyrethrin manifested by immune photochemistry and image analysis of growth associated protein-43, a neuron specific protein present in arsenal growth cone and a marker for neuronal differentiation as per the study of Aziz[9]....

    [...]

  • ...There was insult to the nervous tissue by pyrethrin manifested by immune photochemistry and image analysis of growth associated protein-43, a neuron specific protein present in arsenal growth cone and a marker for neuronal differentiation as per the study of Aziz[9]....

    [...]