Acute and sub-acute effects of 2-butenoic acid-3-(diethoxy phosphinothioyl) methyl ester (RPR-II) on testis of albino rat

Acute and sub-acute toxic effects of a novel phosphorothionate coded as RPR-II on testis of albino rats were studied. In acute study rats received a single dose of 12.3 mg/kg of RPR-II and sacrificed after 24 hr. For sub-acute study 0.58 mg/kg/day was administered orally to rats for 10 and 21 days. Acute exposure of rats to RPR-II brought no change either in the gonadosomatic index (GSI) or in the structure of testis or in the serum levels of testosterone. Testis glutathione (GSH) level and glutathione S-transferase (GST) activity was significantly decreased whereas, acid phosphatase (AcP) levels increased significantly at 24 hr post-treatment. On 7th day (withdrawal period) after the cessation of the treatment the GSH, GST, AcP, and AkP levels reached to near control. The sub-acute study revealed a significant decrease in GSI on 10th and 21st day of the treatment. In contrast, a time-dependent and significant increased in GSH level and GST activity was observed on 100th and 21st day of post-treatment, except GSH level on 10th day, which was declined. Due to RPR-II treatment the testis AcP and alkaline phosphatase (AkP) levels were significant at both 10th and 21st day of medication but AcP levels were increased whereas AkP levels decreased. The histopathological studies on day 10th showed considerable loss of spermatozoids in testis and at 21st day complete derangement of cellular organization was observed. Testosterone levels decreased significantly on 10th day and remained significantly low at 21st day. However, withdrawal studies showed a recovery in testis of rat treated with RPR-II. GST, GSH, GSI, AcP and AkP values recovered, testosterone levels were also well recovered but recovery in testis structure remained at a low profile. The present study suggests that RPR-II may cause testicular toxicity in rats affecting the normal functioning of testis and it also gave some new information in withdrawal studies.

Effects of phosphorothionate on the reproductive system of male rats

Acute and Sub-acute toxic effects of a new pesticide phosphorothionate coded as RPR-V on testis of albino rat were studied. For the acute study, rats received a single dose of 30 mg/kg of RPR-V and sacrificed after 24 hours. For the Subacute study, 1.42 mg/kg/day was administered orally to rats for 10 days and 21 days. Acute exposure of rats to RPR-V brought no change either in the Gonadosomatic Index (GSI) or in the structure of testis or in the serum levels of Testosterone. Similarly, no significant change was observed in the Glutathione S-transferase (GST) activity. But, in testis there was significant increased in the reduced Glutathione (GSH) and Acid Phosphatase (AcP), whereas Alkaline Phosphatase (AkP) levels decreased significantly at 24hr post treatment. On 7th day (withdrawal period) after the cessation of the treatment the GSH, AcP, and AkP levels reached to near control. The sub-acute study revealed a significant post treatment. Due to RPR-V treatment the testis AcP levels increased significantly at 21st day of medication but AkP levels decreased both at 10th and 21st day of post treatment. Histopathological studies showed that after 10th day testis showed considerable loss of spermatozoids and at 21st day complete derangement of cellular organization was observed. Testosterone levels decreased significantly after 10th day and remained significantly low at 21st day. However, withdrawal studies showed a recovery in testis of rat treated with RPR-V. GST, GSH, GSI, AcP and AkP values were recovered, testosterone levels were also recovered but recovery in testis structure remained at a low profile.

Effects of Vepacide (Azadirachta indica) on aspartate and alanine aminotransferase profiles in a subchronic study with rats

The aim of this study was to ascertain the long-term effects of Vepacide, a neem-based pesticide on biochemical profiles. Albino Wistar rats were treated orally with 80 (low), 160 (medium) and 320 mg/kg (high) doses of Vepacide in coconut oil for 90 days. Control rats received the same volume of the vehicle. Vepacide caused increase of aspartate and alanine aminotransferase in serum, kidney and lung, and these enzymes decreased in liver in both male and female rats when measured after 45 and 90 days of treatment. The two-way analysis of variance (ANOVA) showed that the alterations in these enzymes were dose- and time-dependent. Sexual dimorphism was observed when male rats were compared with female rats (Student t-test at P< 0.05). Positive correlation was observed with regard to these enzymes between serum, kidney and lung, whereas in the case of serum and liver, a negative correlation was recorded. These enzyme profiles elucidate that they increased in serum with simultaneous decrease in liver, indicating necrosis of liver, whereas in other tissues, the level of enzymes increased, showing an adaptive mechanism due to the chemical stress. The affected enzymes were recovered to normal conditions after 28 days of post-treatment (withdrawal study). Due to the Vepacide treatment, lung was more affected followed by liver and kidney. This study has indicated that these enzymes could be useful as biomarkers for the insult of any toxicant. Besides, they can also help in predictive toxicology.

Genotoxic effect of monocrotophos to sentinel species using comet assay

Monocrotophos is the single largest selling agrochemical in India. Sensitive biomarkers to study the genotoxic effects caused by monocrotophos in aquatic organisms, especially fish, are lacking. The fish used in this study are Tilapia mossambica, which are edible, commercially valuable and distributed all over India. The objective of this study was to study DNA strand breaks induced by monocrotophos in T. mossambica in vivo using single-cell micro gel electrophoresis/comet assay. Tilapia were treated orally with 0.313, 0.625, 1.25, 1.875, 2.5, 3.125, 3.75 and 4.375 ppm of monocrotophos and the assay was performed on nucleated erythrocytes after 24, 48, 72 and 96 h. A significant increase in mean comet tail-length (5.21-7.46 microM), indicating DNA damage, was observed at all the doses with monocrotophos when compared to controls (3.36 microM). The mean tail-length showed a dose-related increase and time-dependent decrease. The maximum increase in mean comet tail-length was observed at 24 h. Relative to these effects, reductions in mean comet tail-length were seen at 48 and 72 h. By 96 h, values had returned to control levels at all doses, indicating repair of the damaged DNA and/or loss of heavily damaged cells. The study reveals that the comet assay is a sensitive and rapid method to detect genotoxicity of monocrotophos and other environmental pollutants in sentinel species.

Inhibition of acetylcholinesterase and different ATPases by a novel phosphorothionate (RPR-II) in rat brain

A novel phosphorothionate (2-butenoic acid-3-(diethoxy phosphinothioyl)-methyl ester (RPR-II), synthesized at the Indian Institute of Chemical Technology, Hyderabad, targets its effect on rat brain acetylcholinesterase (AChE) and Na(+)-K(+), Mg(2+), and Ca(2+) ATPases, as evident in this investigation. Three subchronic doses 0.014 (low), 0.028 (medium), and 0.042 (high) mg kg(-1) were administered to rats daily for a period of 90 days RPR-II caused statistically significant dose- and time-dependent inhibition in brain AChE and also in Na(+)-K(+), Mg(2+), and Ca(2+) ATPases in both male and female rats after 45 and 90 days of treatment. The low dose was generally insignificant while the medium and high doses were significantly effective. Females were more susceptible than males with regard to brain AChE, Na(+)-K(+), and Mg(2+) ATPases, which indicates sexual dimorphism in the treated rats. Interestingly, after 28 days post-treatment, recovery of these enzymes was observed. The relative sensitivities of these enzymes indicated that brain AChE was more sensitive than any of the ATPases, but among the ATPases Na(+)-K(+) ATPase was more susceptible than Ca(2+) or Mg(2+) ATPases. This compound, besides inhibiting the target of organophosphates, AChE, also inhibited different ATPases, suggesting both synaptic transmission and nerve conduction were affected.

Acid and alkaline phosphatase activities in a novel phosphorothionate (RPR-11) treated male and female rats. Evidence of dose and time-dependent response

The effect of a novel phosphorothionate, the methyl ester of 2-butenoic acid-3-diethoxy phosphinothioyl (RPR-II) was studied on membrane bound target enzymes Acid (AcP) and Alkaline (AkP) Phosphatases in different tissues of male and female albino Wistar rats. Three sub-chronic doses 0.014 (low), 0.028 (medium) and 0.042 (high)mg/kg-1 were administered to the rats daily for a period of 90 days. The long term and repeated administration of RPR-II caused significant increase of AcP and AkP in serum and kidney (AcP), whereas these enzymes simultaneously decreased significantly in liver, kidney (female rat AkP) and lung tissues in both male and female rats after 45 and 90 days of treatment. However, the kidney AcP increased significantly in both the sexes which is suggestive of an increase in synthesis of this enzyme which may be an adaptive mechanism to the toxicant stress. The changes in serum, liver, kidney and lung of both male and female rats by this compound were statistically significant when compared with two way Anova showing that they are dose and time dependent. The alterations in male rats were statistically insignificant when compared with female rats showing no sexual dimorphism by this compound. Recovery was observed after 28 days of post treatment (withdrawal study) indicating reversal of the toxic symptoms once the toxicant is removed. High degree negative correlation was observed for serum versus liver and lung and in other cases substantial correlation was observed. The changes observed in these enzymes showed that liver was most susceptible followed by lung and kidney. There are marker enzymes and their increase in different tissues might be due to the increased permeability of plasma membrane or cellular necrosis, showing the stress condition of the treated rats. This investigation elucidates the effect of these biomarker enzymes which increased in blood, might be due to the necrosis of liver, kidney and lung tissues by this compound.

Sub-chronic effect of neem based pesticide (Vepacide) on acetylcholinesterase and ATPases in rat

Acetylcholinesterases (AChE), Na(+)-K+, Mg2+ and Ca(2+)-ATPases were monitored in rat brain when treated orally with 80, 160 and 320 mg/kg of Vepacide, an active ingredient from neem seed oil, daily for 90 days. Brain AChE, Na(+)-K+ and Ca(2+)-ATPases were inhibited whereas Mg(2+)-ATPase levels were enhanced in both the sexes after 45 and 90 days of treatment. The relative sensitivities of these ATPases to Vepacide indicated that Ca(2+)-ATPase being more sensitive than Na(+)-K(+)-ATPase in both the sexes. The magnitude of Ca(2+)-ATPase inhibited by this compound was higher than that of brain AChE. It appears to be sexual dimorphism in the alterations of brain AChE, Na(+)-K+ and Mg(2+)-ATPases by Vepacide with females being significant when compared with males. After 28 days of post treatment the alterations observed were approached to those of controls both in male and female rats showing reversal of the toxicity. These results indicated that the ATPases were potently inhibited by Vepacide and seemed to be its precise target among the enzyme studied. This can be used as biochemical marker of exposure to this neem derived product.

Biochemical alterations induced by a new phosphorothionate (RPR-II) in tissues of male and female rats

This study was conducted to investigate the effect of a new phosphorothionate, the methyl ester of 2-butenoic acid-3-diethoxy phosphinothioyl (RPR-II) on membrane bound target enzymes aspartate amino transferase (ASAT), alanine amino transferase (ALAT) and RBC acetylcholinesterase (AChE) in different tissues of male and female albino wistar rats when treated orally with 0.014 (low), 0.028 (medium) and 0.042 (high) mg/kg daily for a period of 90 days. Repeated administration of RPR-II caused significant increase of ASAT and ALAT enzymes in serum, liver and kidney and significant decrease was recorded in lung in both male and female rats when measured after 45 and 90 days of treatment. This compound also caused significant inhibition of RBC AChE indicating its effect on nerve synapsis. Females were more susceptible than males with regard to ASAT and ALAT levels in serum and liver and also in kidney ASAT, whereas reverse trend was recorded in lung ALAT, suggesting sexual dimorphism in the treated rats. These studies also indicated that the levels of these affected enzymes were recovered to normal conditions after 28 days of post treatment (withdrawal study). Positive correlation was observed with regard to these enzymes between serum, liver and kidney, whereas in case of serum and lung a negative correlation was recorded. These enzymes profile elucidates lung necrosis whereas in other tissues the level of enzymes increased showing an adaptive mechanism due to the chemical stress.

Effects of a new phosphorothionate (RPR-V) on ATPases and acetylcholinesterase in rat brain by subchronic dosing

The effect of a new phosphorothionate, the ethyl ester of 2-butenoic acid 3-diethoxy phosphinothioyl (RPR-V) synthesized at the Indian Institute of Chemical Technology, Hyderabad was studied using peroral doses of 0.033, 0.066 and 0.099 mg kg(-1) in male and female rats daily over 90 days. This repeated administration of RPR-V caused significant inhibition of acetylcholinesterase, Na+-K+, Mg2+ and Ca2+-ATPases in the brain of male and female rats when measured after 45 and 90 days of treatment. The effects of the low dose were generally not statistically significant, whereas medium and high doses caused significant effects. Females were more susceptible with regard to brain AChE, but the reverse was seen with Mg2+-ATPase, suggesting sexual dimorphism. Enzyme recoveries were seen 28 days after the final dose. Since RPR-V not only inhibited AChE but also ATPases, it is possible that both synaptic transmission and nerve conduction were affected.

Teratism induced in the developing chick by RPR-V, an organophosphate

Fertile White Leghorn chicken eggs were injected on day 4 of incubation with 0, 0.25, 0.50 or 1.00 mg RPR-V/egg and opened on day 20 or allowed to hatch. The following parameters were examined: hatchability, growth and development, external malformations and skeletal deformities. As the dose was increased, the hatchability decreased, and the incidence of deformities increased. Staining of the skeleton with Alizarin red showed clear deformities in the embryos. The results suggest that RPR-V has teratogenic effects on chick embryos when injected on day 4 of incubation.

Haematological and hepatotoxic effects of isoprocarb in chicken

The haematological and hepatotoxic effects were studied after oral administration of Isoprocarb at 75, 112.5 and 150 mg kg-1 daily for 21 days in male and female chicken Gallus gallus domesticus (White Leghorns). The toxic effects as observed 10 or 21 days after medication include a statistically significant reduction in haemoglobin (Hb) content, haematocrit (Ht), protein and serum glutamate pyruvate transaminase (SGPT), and an increase in glucose, serum glutamate oxaloacetate transaminase (SGOT) and serum acid phosphatase (SAP) activities of male and female chicken. The changes in other haematological parameters were generally insignificant, except for one or two doses in RBC, WBC, mean corpuscular haemoglobin concentration (MCHC) and chloride. A significant inhibition of RBC acetylcholinesterase was noticed after 21 days of dosing only at the high dose (150 mg kg-1) in hens. The decrease in food intake and body weights of males and females indicated the overt signs of toxicity. In addition to haematological alterations, the results suggest both hepatotoxic and stress effects and pinpoint that these early biochemical changes induced by Isoprocarb may be predictive of pesticide toxicity.

Acute toxicity and anti acetylcholinesterase potential of some biphenyl derivatives to non target species

Five newly synthesised biphenyl derivatives were evaluated for their acute contact toxicity (LC50) against rice weevil and honey bee and anti acetylcholinesterase potential (I50) against honey bee, fish, pigeon and rat. Amongst, O,O-dimethyl-O, p-Nitro-biphenyl phosphate was most potent against rice weevil, whereas p-(4-Nitrophenyl) phenyl-N-methyl carbamate against honey bee. Based on I50 values the biphenyl derivatives of phosphoric acid esters were more potent anti acetylcholinesterase (AChE) agents against rat and fish brain AChE while derivative of carbamic esters towards pigeon brain AChE. The anti AChE potency of both groups appear to be of the same order towards bee head AChE.

The rate of re-endothelialization correlates inversely with the degree of the following intimal thickening in vein grafts. Electron microscopic and immunohistochemical studies

The distribution of re-endothelialization and the development of intimal thickening were investigated electron microscopically and immunohistochemically using saphenous vein grafts implanted into the femoral artery in dogs. Animals were divided into two groups according to a difference of preparation of the venous grafts before implantation: group 1 without storage, and group 2 with storage for 1 h in 0.9% sodium chloride solution containing papaverine and heparin. In group 2 endothelial cells were almost totally denuded at 1 day, while endothelial islands were always left on the back of valves. In group 1 small islands of surviving endothelial cells were occasionally observed away from the valves. By 1 week, the re-endothelialization of group 1 and group 2 extended to 71 +/- 14.7% and 47 +/- 9% (mean +/- SD) of the total luminal surface area, respectively, and spread mainly from the valves but not from the adjacent artery. Immunohistochemical study using anti-dog fibrinogen IgG suggested that increased permeability of the graft wall continued for one month, in spite of the endothelial covering. Intimal thickening was most pronounced at 1 month, especially near the anastomosis, but was less in the middle of the grafts. These results indicate that intimal thickening of the venous grafts is a response to injury which intimately depends on the rate of re-endothelialization.

Effect of dermal application of phosphamidon-92 (technical) on different tissues and hematobiochemical parameters in albino rat

The histological disturbances occurring from the dermal application of low, medium, and high doses of phosphamidon-92 (technical) to rats as observed by light microscope and analysis of hematobiochemical parameters of blood are presented. Groups of 10 male and 10 female albino rats (Wistar strain) were treated with the test material at dose levels of 0.48 (low), 2.2 (medium), and 3.98 (high) mg/kg X d for 3 wk, followed by a 2-wk observation period. During application, a reduction in food intake and in body weight was recorded with all three treatments. However, gain in body weight and food intake resumed during the observation period and was marked with the high-dose treatment only. Symptoms like hypersalivation and frothing were noticed in both the sexes, as well as a relative decrease in liver weight and gross pathological alterations on microscopical examination of skin, lung, kidney, and testis; significant alterations in some hematobiochemical parameters of blood were observed.