Preventive Efficacy of Bulk and Nanocurcumin Against Lead-Induced Oxidative Stress in Mice

Chronic lead exposure is associated with several health disorders in humans and animals. Lead exposure leads to the generation of reactive oxygen species and depletes body antioxidant enzymes causing damage to various macromolecules and ultimately cell death. Curcumin has been widely recognized to protect against metal toxicity but has major limitations of reduced bioavailability. Nanoencapsulation of curcumin could be an effective strategy to combat lead induced toxic manifestations. The present study investigates the protective efficacy of bulk and nanocurcumin against lead-induced toxicity. Swiss albino mice were daily exposed to lead acetate (25 mg/kg, i.p.) alone and after 1 h treated either with curcumin (15 mg/kg, orally) or nanocurcumin (15 mg/kg, orally) for two consecutive weeks. The preventive efficacy of nanocurcumin was evaluated against various altered biochemical variables suggestive of oxidative stress and lead accumulation in blood and soft tissues. Coadministration of nanocurcumin with lead restored the altered δ-aminolevulinic acid dehydratase activity, glutathione (reduced and oxidized) levels, and also decreased reactive oxygen species, and thiobarbituric acid reactive substances levels. Nanocurcumin due to its possible chelating property and enhanced bioavailability efficiently removed lead from blood and soft tissues compared to bulk curcumin. Results demonstrate the enhanced preventive efficacy of nanocurcumin and suggest an interesting and novel approach for better treatment of lead toxicity.     

Reproductive and embryological toxicity of lead acetate in male mice and their offspring and mitigation effects of quercetin

Exposure to heavy metals not only impacts on fertility in males, it may also affect the offspring. The aim of the present study was to examine the toxic effects of lead acetate on fertility in male mice and their offspring, and the potential effect of quercetin on mitigating the likely effects. Experimental mice were randomly divided into three groups and administered with (i) distilled water (control); (ii) lead acetate (150 mg/kg BW/day); (iii) lead acetate (150 mg/kg BW/day) with quercetin (75 mg/kg BW/day). Lead acetate administration in male mice adversely affected their fertility through changes in sperm motility, viability, morphology, maturity, membrane integrity, and intracellular reactive oxygen species (P < 0.05). Similar findings were observed in the offspring of the lead-treated male mice. Early embryonic development and implantation rate were also adversely influenced in both the sires and offspring when male mice were treated with lead acetate (P < 0.05). The data demonstrated that down-regulation of Cks2 (CDC28 protein kinase regulatory subunit-2) in sperm had an association with early embryonic development in lead acetate treated group. In conclusion, lead acetate administration adversely impacted on the fertility of the male mice and their male offspring fertility; on the other hand, paternal quercetin co-administration somewhat ameliorated the adverse effects of lead on male mice and their offspring.     

Hydroalcoholic Seed Extract of Coriandrum sativum (Coriander) Alleviates Lead-Induced Oxidative Stress in Different Regions of Rat Brain

Lead exposure is known to cause apoptotic neurodegeneration and neurobehavioral abnormalities in developing and adult brain by impairing cognition and memory. Coriandrum sativum is an herb belonging to Umbelliferae and is reported to have a protective effect against lead toxicity. In the present investigation, an attempt has been made to evaluate the protective activity of the hydroalcoholic extract of C. sativum seed against lead-induced oxidative stress. Male Wistar strain rats (100–120 g) were divided into four groups: control group: 1,000 mg/L of sodium acetate; exposed group: 1,000 mg/L lead acetate for 4 weeks; C. sativum treated 1 (CST1) group: 250 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure; C. sativum treated 2 (CST2) group: 500 mg/kg body weight/day for seven consecutive days after 4 weeks of lead exposure. After the exposure and treatment periods, rats were sacrificed by cervical dislocation, and the whole brain was immediately isolated and separated into four regions: cerebellum, hippocampus, frontal cortex, and brain stem along with the control group. After sacrifice, blood was immediately collected into heparinized vials and stored at 4 °C. In all the tissues, reactive oxygen species (ROS), lipid peroxidation products (LPP), and total protein carbonyl content (TPCC) were estimated following standard protocols. An indicator enzyme for lead toxicity namely delta-amino levulinic acid dehydratase (δ-ALAD) activity was determined in the blood. A significant (p?<?0.05) increase in ROS, LPP, and TPCC levels was observed in exposed rat brain regions, while δ-ALAD showed a decrease indicating lead-induced oxidative stress. Treatment with the hydroalcoholic seed extract of C. sativum resulted in a tissue-specific amelioration of oxidative stress produced by lead.     

Flaxseed Oil as a Neuroprotective Agent on Lead Acetate-Induced Monoamineric Alterations and Neurotoxicity in Rats

Lead remains a considerable occupational and public health problem, which is known to cause a number of adverse effects in both man and animals. Here, the neuroprotective effect of flaxseed oil (1,000 mg/kg) on lead acetate (20 mg/kg) induced alternation in monoamines and brain oxidative stress was examined in rats. The levels of lead, dopamine (DA), norepinephrine (NE), serotonin (5-HT), lipid peroxidation, nitrite/nitrate (NO), and glutathione (GSH) were determined; also, the activity of acetylcholinesterase (AChE) and Na(+)-K(+)-ATPase were estimated on different brain regions of adult male albino rats. The level of lead was markedly elevated in different brain regions of rats. This leads to enhancement of lipid peroxidation and NO production in brain with concomitant reduction in AChE activity and GSH level. In addition, the levels of DA, NE, and 5-HT were decreased in the brain. These findings were associated with BAX over expression. Treatment of rats with flaxseed oil induced a marked improvement in most of the studied parameters as well as the immunohistochemistry features. These data indicated that dietary flaxseed oil provide protection against lead-induced oxidative stress and neurotoxic effects.     

Myelin Deficits Produced by Early Postnatal Exposure to Inorganic Lead or Triethyltin Are Persistent

Abstract: Long-Evans rat pups were exposed to either inorganic lead (400 mg Pb as lead acetate/kg body weight/day) or triethyltin sulfate (1.0 mg/kg body weight/day), by gastric intubation, from 2 days through 29 days of age. The rats were then weaned and placed on standard lab chow ad libitum. At 30 days of age, leadtreated rats exhibited statistically significant decreases in body and brain weights (22% and 17%, respectively), and the concentration of forebrain myelin was significantly reduced, by 21% relative to the 4.9 mg myelin protein/g brain in control rats. Although these animals recovered from the body weight deficits after several months, the deficits in brain weight and myelin concentration were still present at 120 days of age. This suggests that the lead-induced myelin deficits were permanent. Lead levels in brain, which were maximal at 30 days of age when the treatment was terminated, decreased more slowly than in other organs and were still 30% of maximal levels at 120 days of age. Triethyltin-treated animals also had significantly decreased body and brain weights (20% and 11%, respectively) at 30 days of age, and an even more severe reduction in forebrain myelin concentration (33%). These animals also regained a normal body weight by 120 days of age, but again the deficits in brain weight and myelin concentration persisted. Tin levels in brain and other organs had decreased to control levels by 60 days of age. Animals malnourished by maternal deprivation to match the body weights of the treated animals had myelin deficits that were less severe than those in the treated animals at 30 days of age (approximately 11% less than controls); however, these myelin deficits also persisted throughout the subsequent 90-day recovery period examined. The apparent lack of recovery from CNS myelin deficits produced by neonatal exposure to different heavy metals or to malnutrition reemphasizes the vulnerability of the developing nervous system to a wide range of metabolic insults.     

Prophylactic effect of melatonin on lead-induced inhibition of heme biosynthesis and deterioration of antioxidant systems in male rats

We studied the protective role of the pineal hormone melatonin on lead-induced suppression of the heme synthesis pathway as a consequence of reduced antioxidant systems in rat. We injected rats intramuscularly with lead acetate (10 mg/kg body weight) daily for 7 days, which significantly abolished heme synthesis as evidenced by decreased blood hemoglobin, liver delta-aminolevulinic acid synthetase, erythrocytic delta-aminolevulinic acid dehydratase, and hepatic iron content. These effects were accompanied with marked elevation of hepatic lipid peroxidation and decreased enzymatic antioxidants such as glutathione reductase, glutathione-S-transferase, superoxide dismutase, and catalase, as well as nonenzymatic antioxidants such as total sulfhydryl groups and glutathione. Furthermore, lead treatment caused hepatic deficiency in copper and zinc accompanied by a significant elevation of lead concentration in both plasma and liver. Daily pretreatment with melatonin (30 mg/kg body weight) intragastrically prevented the suppressive effects of lead on heme-synthesizing enzymes and iron deficiency. In addition, preadministration of melatonin reduced the inhibitory effect of lead on both enzymatic and nonenzymatic antioxidants. This was accompanied by marked normalization of lipid peroxidation and modulation of copper and zinc levels in liver. The action of melatonin on lead-induced changes was attributed to protection of the antioxidant capacity in cells in addition to the ability of melatonin to scavenge free radicals.     

Lead induced alterations in nitrite and nitrate levels in different regions of the rat brain

Nitric oxide (NO) is a free radical synthesized by nitric oxide synthase (NOS) during the conversion of l-arginine to citrulline. Lead (Pb) affects neuronal functioning in the rat brain. Nitric oxide, a neuronal messenger has a short half life and converts immediately into nitrite and nitrate. The present study is designed to determine lead-induced alterations in NO production by measuring nitrite and nitrate in the cerebellum, the hippocampus, the frontal cortex and the brain stem of the rat brain. Male Sprague–Dawley rats were treated with lead acetate (5 and 15 mg/kg body wt.) by intraperitoneal injection. The control and experimental rats were sacrificed at the end of 7 and 14 days after treatment and different regions of the brain were isolated. Nitrite and nitrate (NOx) levels were estimated by the chemiluminescent method using the NOA 280 (Sievers). The data suggested dose-dependent and region-specific responses to lead. Both treatments of lead reduced NOx levels in the cerebellum and the hippocampus. However, the frontal cortex and the brain stem responded differently to Pb exposure. NOx levels in the frontal cortex were significantly increased in rats treated with low and high doses of Pb for 7 days but not in rats treated for 14 days, whereas in the brain stem, NOx levels were increased in a dose- and time-dependent manner. Although, the response was time-dependent, the variation between 7- and 14-day treatment was not clearly delineated. These results provide additional evidence that Pb exposure alters NO-production in rat brain leading to neuronal dysfunction.     

Antioxidant effects of Emblica officinalis and Zingiber officinalis on arsenic and lead induced toxicity on Albino rats

It is of interest to document the effect of Emblica officinalis (E. officinalis) and Zingiber officinalae (Z. officinalae) leaf extract on reactive oxygen species, antioxidant potential changes in arsenic and lead-induced toxicity in male rats. We used 8 groups of adult male Wistar rats with 1 control group for this study. The animals were divided into Group I: Control and Group II: Lead and sodium arsenite induced rats (animals were induced for metal toxicity by the combined administration of arsenic (13.8 mg/ kg body weight) and lead (116.4 mg/kg body weight). These doses were administered by gastric intubation during 14 consecutive days using known standard procedures. Arsenic and lead induced rats treated with ethanolic extract of Emblica officinalis (60 mg/kg body weight/day, orally for 45 days) are group III rats. Group IV animals are arsenic and lead induced rats treated orally with ethanolic extracts of E. officinalis (120 mg/kg body weight/day for 45 days). Group V animals are arsenic and lead induced rats treated orally with ethanolic extracts of Z. officinalae (60 mg/kg body weight/day for 45 days). Group VI animals are arsenic and lead induced rats orally treated with ethanolic extracts of Zingiber officinalis (120 mg/kg body weight/day for 45 days). Group VII animals are arsenic and lead induced rats treated orally with ethanolic extracts of E. officinalis and Z. officinalae (60 + 60 mg/kg body weight/day for 45 days). Group VIII animals are arsenic and lead induced rats treated orally with ethanolic extracts of E. officinalis and Z. officinalae (120 + 120 mg/kg body weight/day, orally for 45 days). Normal Control animals were treated orally with ethanolic extracts of E. officinalis (120mg/kg body weight) + Z. officinalae (120mg/kg body weight) for 45 days. The control and experimental animals were then subjected to analysis for oxidative stress markers such as H2O2, *OH, and lipid peroxidation (LPO), antioxidant enzymes in addition to liver and kidney function markers. Results: Arsenic and lead induced rats showed a significant increase in the levels of reactive oxygen species (H2O2, OH* and LPO) with concomitant alterations in the renal and liver tissues. However, enzymic and non-enzymic antioxidant levels were decreased. Nevertheless, an oral effective dose of E. officinalis and Z. officinalae (120 + 120 mg/kg body weight/day increased the antioxidant enzymes and retrieved the altered levels of ROS and LPO that were induced by arsenic and lead. Thus, we show that E. officinalis and Z. officinalae leaf extract exhibits nephroprotective and hepatoprotective role through the restoration of reactive oxygen species and antioxidant enzymes in the kidney and liver tissue of Arsenic and Lead-induced nephrotoxicity and hepatotoxicity in rats. Hence, E. officinalis and Z. officinalae leaf extract are potential therapeutic options for the treatment of metal toxicity-induced kidney and liver diseases.     

The antidiabetic activity of aloes: preliminary clinical and experimental observations

The dried sap of the aloe plant (aloes) is one of several traditional remedies used for diabetes in the Arabian peninsula. Its ability to lower the blood glucose was studied in 5 patients with non-insulin-dependent diabetes and in Swiss albino mice made diabetic using alloxan. During the ingestion of aloes, half a teaspoonful daily for 4-14 weeks, the fasting serum glucose level fell in every patient from a mean of 273 +/- 25 (SE) to 151 +/- 23 mg/dl (p less than 0.05) with no change in body weight. In normal mice, both glibenclamide (10 mg/kg twice daily) and aloes (500 mg/kg twice daily) induced hypoglycaemia after 5 days, 71 +/- 6.2 and 91 +/- 7.6 mg/dl, respectively, versus 130 +/- 7 mg/dl in control animals (p less than 0.01); only glibenclamide was effective after 3 days. In the diabetic mice, fasting plasma glucose was significantly reduced by glibenclamide and aloes after 3 days. Thereafter only aloes was effective and by day 7 the plasma glucose was 394 +/- 22.0 versus 646 +/- 35.9 mg/dl, in the controls and 726 +/- 30.9 mg/dl in the glibenclamide treated group (p less than 0.01). We conclude that aloes contains a hypoglycaemic agent which lowers the blood glucose by as yet unknown mechanisms.     

N-acetylcysteine exposure on lead-induced lipid peroxidative damage and oxidative defense system in brain regions of rats

Lead (Pb) is known to disrupt the pro-oxidant/antioxidant balance of tissues, which leads to biochemical and physiological dysfunction. Oxidative stress is considered a possible molecular mechanism involved in Pb neurotoxicity. Considering the vulnerability of the brain to oxidative stress under Pb neurotoxicity, this study investigated the effects of exposure of the thiol antioxidant N-acetylcysteine (NAC) on lead-induced oxidative damage and lipid peroxidation in brain regions of the rat. Wister strain rats were exposed to lead in the form of lead acetate (20 mg/kg body wt/d) for a period of 2 wk and the effects of NAC on lead-induced neurotoxicity in rat brain regions were assessed by postadministration of NAC (160 mg/kg body wt/d) for a period of 3 wk. The lipid peroxidation byproduct, malondialdehyde (MDA) increased following lead exposure in both of the regions, and the antioxidant capacities of the cell in terms of the activity of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) was diminished. Following NAC treatment, lead-induced lipid peroxidation decreased and antioxidant enzyme activities improved, with CAT showing enhancement in the cerebral region only and SOD showing enhancements in the cerebellar region. Our result suggests that thiol-antioxidant supplementation following Pb exposure might enhance the reductive status of brain regions by arresting the lipid peroxidative damage in brain regions.     

Prophylactic Efficacy of <Emphasis Type="Italic">Coriandrum sativum</Emphasis> (Coriander) on Testis of Lead-Exposed Mice

Lead poisoning is a worldwide health problem, and its treatment is under investigation. The aim of this study was to access the efficacy of Coriandrum sativum (coriander) in reducing lead-induced changes in mice testis. Animal exposed to lead nitrate showed significant decrease in testicular SOD, CAT, GSH, total protein, and tissue lead level. This was accompanied by simultaneous increase in the activities of LPO, AST, ALT, ACP, ALP, and cholesterol level. Serum testosterone level and sperm density were suppressed in lead-treated group compared with the control. These influences of lead were prevented by concurrent daily administration of C. sativum extracts to some extent. Treating albino mice with lead-induced various histological changes in the testis and treatment with coriander led to an improvement in the histological testis picture. The results thus led us to conclude that administration of C. sativum significantly protects against lead-induced oxidative stress. Further work need to be done to isolate and purify the active principle involved in the antioxidant activity of this plant.     

Mortality in Swiss albino mice after i.p. injection of oxazepam in dimethyl sulphoxide.

Twenty percent of the Swiss albino mice administered with a single dose (60 mg/kg) of oxazepam dissolved in dimethyl sulphoxide (DMSO) died within 7 days. Similarly high mortality rate (37%) was observed in diazepam sensitive mice derived from a Swiss albino stock. In contrast, zero mortality was observed in Swiss albino mice administered with DMSO or diazepam (35 mg/kg). Mortality at 60 mg/kg diazepam was only 10%. The high mortality caused by oxazepam in Swiss albino mice seemed to be strain-related as only 7% mortality was observed with identically treated BALB/c mice. Since DMSO is the only convenient vehicle for the administration of oxazepam by injection, it is suggested that a suitable strain must be selected for experimentation in order to avoid unnecessary loss of animals.     

Motor behavior and brain enzymatic changes after acute lead intoxication on different strains of mice

Lead is a nonphysiological metal that has been implicated in toxic processes that affect several organ systems in humans and other animals. Although the brain generally has stronger protective mechanisms against toxic substances than other organs have, exposure to lead results in several neurophysiological and behavioral symptoms. The administration of a single injection (i.p.) of lead acetate in mice is a model of acute Pb2 + toxicity. In the present study, this model was used to explore the magnitude of the effect of different doses, time intervals and mice strains on several biobehavioral parameters. We investigated the effects of acute lead acetate administration on body and brain weight, brain lead acetate accumulation and specially, spontaneous locomotion and brain catalase activity. Lead acetate was injected i.p. in outbred (Swiss or CD1) and inbred (BALB/c, C57BL/J6 or DBA/2) mice at doses of 0, 50, 100, 150 or 200 mg/kg. At different time intervals following this acute treatment, several biochemical, physiological and behavioral responses were recorded. Results indicated that acute lead acetate has deleterious dose-dependent effects on brain and body weight. The effect on body weight in the present study was transient, although lead acetate was detected in neural tissues for several days after administration. Spontaneous locomotor activity only was reduced up until 24 hours. The effect of lead on body weight was strain-dependent, with Swiss mice showing greater resistance compared to the other strains. Total brain catalase activity in lead-pretreated Swiss mice showed a significant induction. This enzymatic upregulation could provide a protective mechanism for oxidative stress in these mice.     

Protective effect of aqueous garlic extract against lead-induced hepatic injury in rats

Effect of aqueous extract of garlic on hepatic injury due to lead-induced oxidative stress in experimental rats has been investigated. Lead acetate (LA) at a dose of 15 mg/kg body wt was administered ip to rats for 7 consecutive days to induce hepatic injury. Freshly prepared aqueous garlic extract (AGE) at a dose of 50 mg/kg body wt was fed orally to rats 1 h before LA treatment for similar period. LA treatment caused hepatic injury as evident from increased activities of serum glutamate pyruvate transaminase (SGPT) and alkaline phosphatase (ALP), increased serum bilirubin level and damage in the tissue morphology. Lead-induced oxidative stress in liver was evident from increased levels of lipid peroxidation and reduced glutathione. The decreased activity of superoxide dismutase (SOD) and an increased activity of catalase as well as an increased activity of xanthine oxidase (XO) indicate generation and possible accumulation of reactive oxygen intermediates. Furthermore, altered activities of lactate dehydrogenase (LDH), isocitrate dehydrogenase (ICDH), alpha-keto glutarate dehydrogenase (alpha-KGDH) and succinate dehydrogenase (SDH) also indicate an impaired substrate utilization and generation of oxidative stress. All these changes were found to be mitigated when the rats were pre-treated with the AGE. Results indicate that AGE has the potential to ameliorate lead-induced hepatic injury due to oxidative stress in rats. The protective effects may be due to the antioxidant properties of AGE and may have future therapeutic relevance.     

Curcumin-loaded cockle shell-derived calcium carbonate nanoparticles: A novel strategy for the treatment of lead-induced hepato-renal toxicity in rats

Lead (Pb) toxicity affects the hepatic and renal systems resulting to homeostasis imbalance. Curcumin is a strong antioxidant but has restrained clinical applications due to its poor bioavailability. Nanomedicine showed promising potentials in drug delivery and has brought forth the use of cockle shell-derived aragonite calcium carbonate nanoparticles (CSCaCO₃NP) to enhance the effectiveness and targeted delivery of curcumin (Cur). Thus, this study aimed at evaluating the therapeutic effect of curcumin-loaded CSCaCO₃NP (Cur- CSCaCO₃NP) on lead-induced hepato-renal toxicity in rats. Thirty-six male adults Sprague-Dawley rats were randomly assigned into five groups. All groups contained six rats each except for group A, which contained 12 rats. All rats apart from the rats in group A (control) were orally administered a flat dose of 50 mg/kg of lead for four weeks. Six rats from group A and B were euthanized after four weeks of lead induction. Oral administration of curcumin (100 mg/kg) for group C and Cur-CSCaCO₃NP (50 and 100 mg/kg) for groups D and E respectively, commenced immediately after 4 weeks of lead induction which lasted for 4 weeks. All rats were euthanized at the 8th week of the experiment. Further, biochemical, histological and hematological analysis were performed. The findings revealed a biochemical, hematological and histological changes in lead-induced rats. However, treatments with the Cur-CSCaCO₃NP and free curcumin reversed the aforementioned changes. Although, Cur-CSCaCO₃NP presented better therapeutic effects on lead-induced toxicity in rats when compared to free curcumin as there was significant improvements in hematological, biochemical and histological changes which is parallel with attenuation of oxidative stress. The findings of the current study hold great prospects for Cur-CSCaCO₃NP as a novel approach for effective oral treatment of lead-induced hepato-renal impairments.     

Response of lead-induced oxidative stress and alterations in biogenic amines in different rat brain regions to combined administration of DMSA and MiADMSA

The present study was planned to investigate if combined administration of meso-2,3-dimercaptosuccinic acid (DMSA) and monoisoamyl DMSA (MiADMSA) could achieve better recovery in the altered biochemical parameters suggestive of brain oxidative stress and depletion of lead from blood and brain following acute lead exposure. Male Wistar rats were exposed to lead nitrate (50 mg/kg, i.p., once daily for 5 days) followed by treatment with the above chelating agents using two different doses of 25 or 50 mg/kg (orally) either alone and in combination once daily for five consecutive days. Lead exposure resulted in the significant inhibition of δ-aminolevulinic acid dehydratase activity and depletion of glutathione (GSH) in blood. These changes were accompanied by significant reduction in blood hemoglobin, RBC levels and superoxide dismutase and catalase activities. Significant increase in blood reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) levels were noted. We observed marked increase in brain ROS level while GSH/oxidized glutathione ratio showed significant decrease accompanied by a significant increase in blood and brain lead concentration. The levels of norepinephrine, dopamine and serotonin in different brain regions were also altered on lead exposure. Co-administration of DMSA and MiADMSA particularly at the lower dose was most effective in the recovery of lead-induced changes in the hematological variables and oxidative stress and resulted in more pronounced depletion of lead from blood and brain compared to monotherapy with these chelators. On the other hand, combined administration of MiADMSA (50 mg/kg) in combination with DMSA (25 mg/kg each) had additional beneficial effect over the individual effect of chelating agent in the recovery of altered levels of brain biogenic amines. The study suggests that administration of MiADMSA is generally a better lead chelator than DMSA while combined administration of DMSA and MiADMSA might be a better treatment option compared to monotherapy at least in the removal of lead from the target tissues.     

Naringenin alleviate reproductive toxicity evoked by lead acetate via attenuation of sperm profile and biochemical alterations in male Wistar rat: Involvement of TGFβ/AKT/mTOR pathway

Exposure to Lead -causes testicular dysfunction through oxidative stress, inflammation, and apoptosis; however, naringenin (NGN) therapeutic impact against lead-evoked testicular dysfunction remains elusive. Herein, the point of the study was to examine the defensive impact of NGN on testicular dysfunction initiated by lead. Seventy-Two male Wistar rats were allotted into nine groups; control group, drug control groups, lead acetate group, as well as NGN treated groups (10, 25, and 50 mg/kg) respectively, given 5 days before lead acetate treatment. The result showed clearly the impact of lead on reduced sperm count, sperm motility as well as serum testosterone and LH levels. Additionally, it caused a significant rise in testicular inflammatory markers TNF-α, IL-1β, and TGFβ, effects that were accompanied by a reduction of AKT and mTOR levels. Lead acetate also caused degenerative changes in the testis, atrophy, and loss of spermatogenic series. Our findings revealed that NGN in a dose-dependent manner improved spermiotoxicity induced by lead acetate via restoration of the testicular function, preservation of spermatogenesis, halting inflammatory cytokines along with the enhancement of germ cell survival using upregulation of AKT/mTOR expressions. The present study discloses that NGN suppresses lead acetate toxicity that is involved in the antioxidant effect in a dose-dependent manner, besides its anti-inflammatory property.     

Protective action of vitamins on the spermatogenesis in lead-treated Swiss mice

The protective action of vitamins C and E against lead acetate-induced reduced sperm count and sperm abnormalities in Swiss mice has been studied. Intraperitoneal injection of lead acetate (10mg/kg body weight) in the present study stimulates lipid peroxidation in the testicular tissue, indicated by a significant increase in malondialdehyde content in the experimental mice group. This is associated with an increased generation of noxious reactive oxygen species (ROS). Significantly reduced sperm count associated with increased sperm abnormality percentage in the lead-injected mice group compared to controls substantially proves the ongoing damaging effects of lead-induced ROS on developing germ cells. However, intraperitoneal administration of vitamin C (Vit C) at a concentration equivalent to the human therapeutic dose (10 mg/kg body weight) was able to minimize significantly the testicular malondialdehyde content with a concomitant increase in sperm count and significant decrease in the percentage of abnormal sperm population. Vitamin E (Vit E) (100 mg/kg body weight) treatment of a batch of lead-injected mice had a similar effect as Vit C but with a comparatively lower efficacy. On the other hand, coadministration of both vitamins (Vit C + Vit E) at the above mentioned doses to lead-treated mice led to the most significant decline in malondialdehyde content along with elevated sperm count and reduction in the percentage of abnormal sperm population. The protective action and the synergistic action of both vitamins (C and E) against lead-induced genotoxicity are discussed.     

Ginkgo biloba supplement abates lead-induced endothelial and testicular dysfunction in Wistar rats via up-regulation of Bcl-2 protein expression,pituitary-testicular hormones and down-regulation of oxido-inflammatory reactions

BackgroundApoptotic and oxido-inflammatory pathways have been found to be up-regulated in lead acetate poisoning which has been associated to endothelial and testicular dysfunctions. It is yet uncertain, nevertheless, if treatment with Ginkgo biloba supplements (GBS), a flavonoid-rich natural product can lessen the adverse effects of lead on endothelial and testicular functions. This study investigated the impact of Ginkgo biloba supplementation on lead-induced endothelial and testicular dysfunctions.MethodsThe animals were treated with GBS (50 mg/kg and 100 mg/kg orally) for 14 days following oral exposure to lead acetate (25 mg/kg) for 14 days. After euthanasia, blood samples, epididymal sperm, testes, and aorta were collected. The quantities of the hormones (testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH), as well as the anti-apoptotic, oxidative, nitrergic, inflammatory markers, were then determined using immunohistochemistry, ELISA, and conventional biochemical methods.ResultsGBS reduced lead-induced oxidative stress by increasing the levels of the antioxidant enzymes catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD), while lowering malondialdehyde (MDA) in endothelium and testicular cells. Normal testicular weight was restored by GBS which also decreased endothelial endothelin-I and increased nitrite levels. TNF-α and IL-6 were decreased while Bcl-2 protein expression was enhanced. Lead-induced alterations in reproductive hormones (FSH, LH, and testosterone) were also restored to normal.ConclusionAccording to our result, using Ginkgo biloba supplement prevented lead from causing endothelial and testicular dysfunction by raising pituitary-testicular hormone levels, boosting Bcl-2 protein expression and lowering oxidative and inflammatory stress in the endothelium and testes.     

Dietary grape seed procyanidin extract protects against lead-induced heart injury in rats involving endoplasmic reticulum stress inhibition and AKT activation

To investigate the protective role of grape seed procyanidin extract (GSPE) against lead-induced heart injury and the possible molecular mechanism associated with this event, Wistar rats were orally given GSPE (200 mg/kg) daily with or without lead acetate (PbA) (0.5 g/L) in drinking water for 56 d. GSPE attenuated oxidative stress, heart dysfunction, and lead accumulation in lead-exposed rat hearts. Meanwhile, GSPE inhibited the protein kinase RNA-like endoplasmic reticulum (ER) kinase/eukaryotic initiation factor 2α signaling pathway, and promoted protein kinase B (AKT) and glycogen synthase kinase 3β phosphorylation altered by lead, and regulated lead-activated apoptosis and its related signaling pathway. This study suggests that dietary GSPE ameliorates lead-induced heart injury associated with ER stress inhibition and AKT activation. Dietary GSPE may be a protector against lead-induced heart injury and a novel therapy for lead exposure.