Evaluation of the Pharmacological Potential of Strychnos camptoneura Trunk Bark Hydroethanol Extract on Reproductive Functions in Male Guinea Pigs (Cavia porcellus) Exposed to Cypermethrin

The main objective of this study was to evaluate the pharmacological potential of the hydroethanol extract of Strychnos camptoneura trunk bark on reproductive functions in male guinea pigs exposed to cypermethrin. The results showed that administration of the hydroethanolic extract (100 and 250 mg/kg) of Strychnos camptoneura trunk bark after exposure of the animals to cypermethrin induced a highly significant (p Strychnos camptoneura trunk bark produced a highly significant (p Strychnos camptoneura trunk bark may have protective effects against cypermethrin-induced male infertility due to its androgenic, spermatogenic and antiradical properties.

ZETA-CYPERMETHRIN EW对蚊蝇蟑毒效初探

本文报道了ZETA-CYPERMETHRIN EW三个剂量施在3种不同板面上,对蚊蝇蟑毒力测定结果。在玻璃面施药10、20、30mg a.i./m^2,对蚊蝇两试虫,致死率为70％时,持效期均为90天和40mg a.i./m^2时,对蟑螂致死率为100％时,持效90天;油漆面20、30mg a.i./m^2时,致死率在70％时,致死率在70％以上,对蟑螂持效期为60天;石灰面30mg a.i./m^2时,致死率在70％时,持效期分别为蚊60天、蝇0天,水泥面40mg a.i./m^2时,致死率在70％以上,对蟑螂持效期为15天。

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper （Cu） ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied. Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time, the analysis of the extracts from the soil was carded out using gas chromatography （GC）. The photodegradation of pyrethroids in water system was conducted under UV irradiation. The effect of Cu^2＋ on the pesticides degradation was measured with half life 00.5） of degradation. It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed. But Cu^2＋ could accelerate photodegradation of the pyrethroids in water. The t0.5 for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil. As for photodegradation, t0.5 for cyhalothrin reduced from 173.3 to 115.5 min and for cypermethrin from 115.5 to 99.0 min. The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms. However, it had catalyst tendency for photodegradation in water system. The difference for the degradation efficiency of pyrethroid isomers in soil was also observed. Copper could obviously accelerate the degradation of some special isomers.

Effect of cypermethrin insecticide on the microbial community in cucumber phyllosphere

Cucumber (Cucumis sativus) is one of the most widely used vegetable in the world,and different pesticides have been extensively used for controlling the insects and disease pathogens of this plant.However,little is known about how the pesticides affect the microbial community in cucumber phyllosphere.This study was the first attempt to assess the impact of pyrethroid insecticide cyperemethrin on the microbial communities of cucumber phyllosphere using biochemical and genetic approaches.Phospholipid fatty ac...

Effects of Cypermethrin on Male Reproductive System in Adult Rats

Objective To evaluate effects of cypermethrin on the testis histology and testosterone, LH and FSH in adult male Sprague-Dawley rats. Methods The intact adult male rats were randomly divided into five groups and were treated with cypermethrin at doses of 0, 7.5, 15, 30, or 60 mg/kg per day by oral gavage for 15-days. After the treatments, serum was collected for hormone assays. The testes, epididymides, seminal vesicles, and prostates were excised and weighed. The right testis was frozen for daily sperm production and the left one was processed for histopathology. Results Daily sperm production decreased significantly in 30 and 60 mg/（kg.day） groups. Testicular structure abnormalities included atrophic and distorted seminiferous tubules, deformed and disordered arrangement of germ cells, reduced germ cells, Sertoli cells and Leydig cells, vacuolization and multinucleated formations of spermatids in the cypermethrin-treated rats. Vacuolization was found in Sertoli cells and the deformed nucleus was noted in Leydig cells. Serum testosterone reduced significantly in 30 and 60 mg/（kg.day） groups. Serum FSH increased significantly in 60 mg/（kg.day） group. Conclusion Cypermethrin induces impairments of the seminiferous tubules structure and spermatogenesis in the rats. The damages of the male reproductive system may be attributed to the imbalance of circulating testosterone.

Effect of Nitrogen on the Degradation of Cypermethrin and Its Metabolite 3-Phenoxybenzoic Acid in Soil

Increasing use of pyrethroid insecticides has resulted in concerns regarding potential effects on human health and ecosystems. Cypermethrin and its metabolite 3-phenoxybenzoic acid(PBA) have exerted adverse biological impacts on the environment;therefore,it is critically important to develop different methods to enhance their degradation. In this study,incubation experiments were conducted using samples of an Aquic Inceptisol supplied with nitrogen(N) in the form of NH4NO3 at different levels to investigate the effect of nitrogen on the degradation of cypermethrin and PBA in soil. The results indicated that appropriate N application can promote the degradation of cypermethrin and PBA in soil. The maximum degradation rates were 80.0% for cypermethrin after 14 days of incubation in the treatment with N at a rate of 122.1 kg ha-1 and 41.0% for PBA after 60 days of incubation in the treatment with N at a rate of 182.7 kg ha-1. The corresponding rates in the treatments without nitrogen were 62.7% for cypermethrin and 27.8% for PBA. However,oversupplying N significantly reduced degradation of these compounds. Enhancement of degradation could be explained by the stimulation of microbial activity after the addition of N. In particular,dehydrogenase activities in the soil generally increased with the addition of N,except in the soil where N was applied at the highest level. The lower degradation rate measured in the treatment with an oversupply of N may be attributed to the microbial metabolism shifts induced by high N.

Assessing cypermethrin-contaminated soil with three different earthworm test methods

A series of tests (lethal,sublethal,and behavioral) on earthworms were conducted as an eco-assessment of pesticides.In this study,the toxicity of cypermethrin-contaminating soil on adult and juvenile earthworms was assessed.Beside the acute and chronic tests,an avoidance response test was carried out.It was shown that the all-round toxicity from cypermethrin was weak on adult earthworms.Compared with adult earthworms,the toxicity of juvenile earthworms from cypermethrin especially chronic toxicity increased...

Acute Toxicity of Clethodim, Cypermethrin and 2,4-D-butylate to the Larva of Chironomus sinicus

[Objective] The aim of this study was to detect the acute toxicity of clethodim, cypermethrin and 2,4-D-butylate. [Method] Chironomus sinicus larvae were exposed to different concentrations of clethodim, cypermethrin and 2,4-D-butylate. Survival rate, lethal concentration 50 （LC50） and superoxide dismutase （SOD） activity in the homogenate of the larvae were monitored to detect the toxicity of the pesti- cides. [Result] The survival rates of C. sinicus larvae exposed to cypermethrin and 2,4-D-butylate for 12 h were almost unchanged at different concentrations, but de- creased with concentration increasing 48 h later. For each pesticide, the differences in survival rates of C. sinicus larvae at 48 h were significant. The 48 h LC50 of clethodim, cypermethrin and 2,4-D-butylate to C. sinicus larvae were 1.842, 0.150 and 1.999 mg/L, respectively. The acute toxicity of cypermethrin was the highest a- mong the three pesticides and that of 2,4-D-butylate was the lowest. Clethodim sig- nificantly reduced the SOD content in a dose-dependent manner. 2,4-D-butylate also reduced SOD content in C. sinicus larvae, but the reduction was not significantly re- lated to its dosage. However, cypermethrin showed no significant effect on SOD ac- tivity in C. sinicus larvae.

Enantioselective separation and zebrafish embryo toxicity of insecticide beta-cypermethrin

Enantioselectivity of chiral pollutants is receiving growing concern due to the difference in toxicology and environment fate between enantiomers.In this study,enantiomers of insecticide beta-cypermethrin （beta-CP） were separated on selected chiral column by HPLC,and the toxicity of enantiomers was evaluated using the zebrafish embryo-larval assays.The enantiomers of beta-CP were baseline separated on Chiralcel OD and Chiralpak AD columns and detected by circular dichroism （CD） at 236 nm.Better separation could be achieved at lower temperature （e.g.,20°C） and with lower levels of polar modifiers.Pure enantiomers were obtained on Chiralcel OD.The CD spectra of enantiomers were recorded.By comparing the elution order with a previous similar study,the absolute configuration of beta-CP enantiomers was determined.The individual enantiomers were used in zebrafish embryo test,and the results showed that beta-CP enantioselectively induced yolk sac edema,pericardial edema and crooked body.The 1R-cis-αS and 1R-trans-αS enantiomers showed strong developmental toxicities at concentration of 0.1 mg/L,while the 1S-cis-αR and 1S-trans-αR induced no malformations at higher concentration （e.g.,0.3 mg/L）.The results suggest that the enantioselective toxicological effects of beta-CP should be considered when evaluating its ecotoxicological effects.

The Effect of Adjuvants on Penetration of beta-cypermethrin Through the Epidermis of Cabbage Leaf

The effects of three types of adjuvant (mineral oil, higher aliphatic acid and nonionic surfactant) on the penetration of beta-cypermethrin through the cabbage leaf surface were studied. The results showed that the penetration was positively correlated with both the concentration of adjuvant and the time after application, in a given range of treatment. A synergistic effect of two types of adjuvant on the penetration was found. Some physical properties of emulsions were determined. The change of the structures of the cabbage leaf surface by these adjuvants was observed from photomicrographs. The mechanism concerned with the effect of these adjuvants on the penetration of beta- cypermethrin through the cabbage leaf surface was tentatively discussed.

Evaluation of the Effects of Cypermethrin on Female Reproductive Function by Using Rabbit Model and of the Protective Role of Chinese Propolis

The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethrin induced atypia in the ovary and uterus, and decreased the ovulation sites and the number of embryos. Cypermethrin-induced oxidative stress during pregnancy, decreased the parturition rate as well as the number and weight of offspring and increased the incidence of morphological malformations in the offspring. Administration of propolis to cypermethrin-treated animals mitigated cypermethrin-induced reproductive toxicity.

Removal of Cypermethrin with Seaweed Gracilaria lemaneiformis

Abstract The removal of cypermethrin with a red macroalga, Gracilaria lemaneiformis, was studied under laboratory conditions. Results showed that the residue contents with G. lemaneiformis were significantly lower than those corresponding groups without the algal thalli after 96 h treatment. The removal rates decreased with increasing concentrations, which were about 50% without G. lemaneiformis after 96h exposure, and increased to 89%, 73%, and 66% in flasks with G. lemaneiformis at the concentrations of 10, 100, and 1000 gg L-1, respectively. The amount of biosorption （absorption and adsorption） by G. lemaneiformis increased with the increasing concentration and exposure time. Adsorption was the main process for the removal by G. lemaneiformis, which accounted for 75%-97% of the total biosorption. However, biosorption only contributed 0.5%-19.3% to the total losses of cypermethrin, which was more efficient under the low concentration. Natural losses contributed the largest portion of losses, which was over 65% in all treatments during the experiment. The unknown pathway of removal, which might be the bio-decomposed by microorganisms attaching the algal thalli, also contributed a lot to the total removal. The results suggested that cultivation of G. lemaneiformis could significantly remove cypermethrin, especially at low concentrations, and large-scale cultivation of G. lemaneiformis has considerable potential of biorestoration of eutrophic and cypermethrin-poUuted coastal sea areas.

Acute toxicity of Cypermethrin, a synthetic pyrethroid to estuarine clam Katelysia opima (Gmelin) and its effect on oxygen consumption

The impact of acute exposure of Cypermethrin on the rate of oxygen consumption of the estuarine clam, Katelysia opima was studied. After 12, 24, 36, 48, 60, 72 84 and 96 h of exposure to acute concentration, the average oxygen consumption in LC0 group was 0.215, 0.305, 0364, 0.355, 0.362, 0.376, 0.313, 0.305, 0.297 (ml/L/hr/gm) and in LC50 group it was 0.210, 0.299, 0.356, 0.247, 0.217, 0.244, 0.203, 0.186, 0.174 (ml/L/hr/gm). It was observed that the rate of oxygen consumption fluctuated with an increase in the exposure period. The decrease was maximum in LC50 group as compared to LC0 group.

EFFECTIVENESS OF BETA-CYPERMETHRIN ON GLUTAMIC- PYRUVIC TRANSAMINASE (GPT) AND GLUTAMIC-OXALOACETIC TRANSAMINASE (GOT) ACTIVITIES FROM CRUCIAN CARP (CARASSIUS AURATUS) SERUM

Beta-cypermethrin is one of the synthetic pyrethroid, which is widely used to control insect pests and is found to be more effective than organphosphates and carbamates. However, it is also reported to be more toxic than organphosphates and carbamates. It has been suggested that synthetic pyrethroids are readily absorbed by the gills of fish even at very low concentrations. Glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) exist in the cells of every tissue, particularly in the liver. If the liver is damaged, the enzymes are discharged from the cells into the serum. It increases the GPT and GOT metabolic activities quickly. It is, therefore, proposed that the effects of toxicants on serum GPT and GOT could be used as indexes in toxicological assessments. In this experiment, the effectiveness of beta-cypermethrin on the acute toxicity and on serum GPT and GOT concentration of crucian carp was studied. The LC 50 of beta-cypermethrin for crucian carp was 11.4μg/L. The crucian carp serum was treated against beta-cypermethrin levels of 0.114μg/L, 0.57μg/L and 1.14μg/L for exposure times of 0d, 5d, 10d, 15d and 20d, at all concentrations. The results show that when the beta-cypermethrin concentration increases and the exposure time is prolonged, the GPT and GOT activities of serum increased also. The results proved that beta-cypermethrin could cause great damage to crucian carp and its biochemical functions.

Effects of melatonin on changes in cognitive performances and brain malondialdehyde concentration induced by sub-chronic coadministration of chlorpyrifos and cypermethrin in male Wister rats

Objective:To evaluate the ameliorative effect of melatonin on sub-chronic chlorpyrifos(CPF)and cypermethrin(CYP)-evoked cognitive changes in male Wistar rats.Methods:Fifty adult male Wistar rats,divided into five groups of ten rats each,were used for the study.GroupsⅠandⅡwere given distilled water and soya oil(2 ml/kg)respectively.GroupⅢwas administered with melatonin at 0.5 mg/kg only.GroupⅣwas administered with CPF[7.96 mg/kg(1/10th LD_(50))]and CYP[29.6 mg/kg(1/10th LD_(50))].and Group V was administered with CPF[7.96 mg/kg(1/10th LD_(50)]and CYP[29.6 mg/kg(1/10th LD_(50)]30 min after melatonin(0.5 mg/kg).The regimens were administered by gavage once daily for 12 weeks.Thereafter,cognitive performances were determined and the brain was evaluated for malonaldehyde concentration.Results:CPF and CYP induced cognitive deficits and increased brain malonaldehyde concentration,which were all ameliorated by melatonin.Conclusion:Cognitive deficits elicited by CPF and CYP was mitigated by melatonin due to its antioxidant property.

Inhibitory Effects of Cypermethrin on Interactions of the Androgen Receptor with Coactivators ARA70 and ARA55

Objective The purpose of this study was to investigate the anti-androgenic mechanism of cypermethrin involving coactivators.Methods Mammalian two-hybrid assays were performed to study the effects of cypermethrin on interactions of the androgen receptor(AR)with the coactivators androgen receptor-associated protein70(ARA70)and androgen receptor-associated protein 55(ARA55).Results The results showed that AR–ARA70 and AR–ARA55 interactions were remarkably enhanced by dihydrotestosterone(DHT,P≤0.05).Cypermethrin inhibited DHT-induced AR–ARA70 and AR–ARA55 interactions significantly(P≤0.05).Conclusion The study indicates that cypermethrin exhibits inhibitory effects on AR transcription associated with repression of AR–ARA70 and AR–ARA55 interactions in a ligand-dependent manner.The data show novel anti-androgenic mechanisms of cypermethrin that contribute to male reproductive toxicology.

Kinetic Characteristic of Photooxidation of Cypermethrin by Organic Peroxy Radical

The kinetic characteristic of photolysis of cypermethrin (CPM) sensitized by acetophenone (AP) and the effect of probe substance 2,6-Di-tert-butyl-4-methylphenol and tetralin is studied in this report. It showed that the photolysis rate of CPM increases slightly with the increase of AP concentration; photolysis rate of CPM has no relationship with [CPM] itself; The more dipolar moment the solvent has, the more the interaction between radical and solvent has, and the slower the photolysis of CPM is. The addition of radical probe substance confirms that ROO·is more than RO·. The steady-state concentration of ROO·is about 10?8 mol·L?1.

Toxicity of cypermethrin to Daphnia magna HB

The acute toxic effect of the pesticide cypermethrin to Daphnia magna HB was examined. D. magna HB was exposed to cypermethrin at concentrations of 0, 1, 3, 5, 7, and 9 mg/L for 24 h. Data showed that the 24 h-LC 50 of cypermthrin on D. magna HB was 4.81 mg/L. In contrast, the 24 h-LC 50 of K 2Cr 2O 7(the national standard toxicant) to Daphnia magna was 0.38 mg/L in the current study. Results indicated that the Daphnia magna was very sensitive to pesticides. In addition, the effects of the culture condition(such as hardness, temperature and DO etc.) on Daphnia magna HB was also studied.

Determination of Acute Lethal Doses of Acetamiprid and Cypermethrin for the Native Bee <i>Apis mellifera</i>(Hymenoptera: Apidae) in Cameroon

Honey bees are important pollinators and are essential in agriculture;as such they get exposed to a wide range of pesticides while foraging in contaminated fields or during the spray of chemical on crops. It is therefore important to know the toxicity and evaluate the impacts of bees’ exposure to these molecules. Acetamiprid and cypermethrin are two pesticides widely used in Cameroon and other countries. The objective of this study was to determine the toxicity of acetamiprid and cypermethrin on the native subspecies of Apis mellifera L. in agricultural areas in Adamaoua-Cameroon and to evaluate the impact on honeybee foragers exposed to lethal and sublethal doses of these two insecticides. The results obtained in laboratory conditions show that acetamiprid and cypermethrin are toxic to A. mellifera. The symptoms of neurotoxicity and first mortality appear 15 min after the ingestion of the high concentrations and about 30 to 45 min after the inoculation of the pesticides through contact route and the mortality increases with the concentration and time. The LC50 of acetamiprid obtained after 24 h are respectively 5.26 ng/μl for the topical application and 4.70 μg/μl by the oral route. At the same time, the LC50 of cypermethrin are respectively 2.27 ng/μl for topical application and 2.68 ng/μl for oral toxicity. For a sustainable agriculture and beekeeping, it is, therefore, important to establish quality measures on these insecticides in the ecosystem and to set up a phyto-pharmacovigilance and awareness system to the population.

Bioassay evaluation on the efficacy of a-cypermethrin impregnated into long lasting insecticide treated nets using Anopheles stephensi

Objective:To evaluate the bioefficacy ofα-cypermethrin impregnated into long lasting insecticide treated nets(LLITNs- INTERCEPTOR?) against main malaria vector,Anopheles stephensi（An.stephensi）.Methods:The effectiveness of bed net impregnated withα-cypermethrin(INTERCEPTOR?) with washing was evaluated.The washing procedure and bioassay tests were carried out according to the WHO-recommended methods.Malaria vector, An.stephensi was exposed to impregnated bed net for three minutes and then mortality measured after 24 h recovery period.Knockdown was also measured according to the logarithmic times. Results:Result of cone bioassay method showed that bioefficacy ofα-cypermethrin decreased from 100%in unwashed to 15%in 20 washes.KT50 was measure as one minute in one wash and increased to 40 min in 20 washes.Discussion:Findings of this study provide guideline for malaria vector control authorities and people using pyrethroid-impregnated bed nets.