Chlorpyrifos-induced alterations in the activities of carbohydrate metabolizing enzymes in rat liver: The role of zinc

Exposure to Chlorpyrifos Alters Proliferation, Differentiation and Fatty Acid Uptake in 3T3-L1 Cells

Organophosphorus pesticides (OPs) are important factors in the etiology of many diseases, including obesity and type 2 diabetes mellitus. The aim of this study was to investigate the effect of a representative of OPs, chlorpyrifos (CPF), on viability, proliferation, differentiation, and fatty acid uptake in 3T3-L1 cells. The effect of CPF exposure on preadipocyte proliferation was examined by the MTT, NR, and BrdU assays. The impact of CPF exposure on the differentiation of preadipocytes into mature adipocytes was evaluated by Oil Red O staining and RT-qPCR. The effect of CPF on free fatty acid uptake in adipocytes was assessed with the fluorescent dye BODIPY. Our experiments demonstrated that exposure to CPF decreased the viability of 3T3-L1 cells; however, it was increased when the cells were exposed to low concentrations of the pesticide. Exposure to CPF inhibited the proliferation and differentiation of 3T3-L1 preadipocytes. CPF exposure resulted in decreased lipid accumulation, accompanied by down-regulation of the two key transcription factors in adipogenesis: C/EBPα and PPARγ. Exposure to CPF increased basal free fatty acid uptake in fully differentiated adipocytes but decreased this uptake when CPF was added during the differentiation process. Increased free fatty acid accumulation in fully differentiated adipocytes may suggest that CPF leads to adipocyte hypertrophy, one of the mechanisms leading to obesity, particularly in adults. It can therefore be concluded that CPF may disturb the activity of preadipocytes and adipocytes, although the role of this pesticide in the development of obesity requires further research.

Chlorpyrifos induces apoptosis and necroptosis via the activation of CYP450s pathway mediated by nuclear receptors in LMH cells

Chlorpyrifos (CPF), an organophosphorus pesticide, is detected commonly in environments, where it is thought to be highly toxic to non-target organisms. However, the mechanism of CYP450s pathway mediated by nuclear receptors on CPF-induced apoptosis and necroptosis at the cellular level and the effect of CPF on the cytotoxicity of the chicken hepatocarcinoma cell line (LMH) has also not been reported in detail. Therefore, this experiment aims to explore whether CPF can improve apoptosis and necroptosis in LMH cells by activating the nuclear receptors/CYP450s axis. LMH cells, the subject of this study, were exposed to 5 μg/mL, 10 μg/mL, and 15 μg/mL doses of CPF. With the increase of CPF concentration, the increase of nuclear receptor level led to the up-regulation of CYP450s activity. With the massive production of ROS, the expression of apoptotic pathway genes (Bax, Caspase9, and Caspase3) enhanced, while Bcl-2 expression dropped sharply. The expression of programmed necroptosis genes (RIPK1, RIPK3, and MLKL) heightened, and Caspase8 reduced considerably. In short, our data suggests that excessive activation of nuclear receptors and CYP450s induced by CPF promotes ROS production, which directs apoptosis and programmed necroptosis in LMH cells.

An Overview of Diabetes Mellitus in Egypt and the Significance of Integrating Preventive Cardiology in Diabetes Management

In Egypt, diabetes mellitus (DM) is a significant public health concern, and the disease is considered a modern pandemic throughout the world. The incidence of diabetes is steadily climbing, which is causing grave concern. As a result, it is essential to take into consideration the risk factors that are pervasive in Egyptian society and have led to the worsening of this problem. These risk factors include sedentary lifestyles, obesity, hepatitis C infections, pesticides, smoking, and bad cultural habits. In this review, we aim to demonstrate the possible solutions to fight diabetes mellitus and overcome its serious health and socioeconomic burdens in Egypt. A multidisciplinary, team-based approach is highly recommended in diabetes management. Primary care physicians, endocrinologists, nephrologists, and preventive cardiologists all play a crucial role in providing the highest possible level of care to diabetic patients by collaborating closely with one another. The assessment of cardiovascular risk and the prevention of life-threatening cardiovascular events, common among diabetic patients, warrant the introduction of preventive cardiology, a new and significant concept in diabetes care that demands adoption. The integration of preventive cardiology into the treatment of diabetic patients is expected to significantly cut down the morbidity and mortality rates associated with diabetes mellitus and provide them with a better quality of life.

A systematic review on the metabolic effects of chlorpyrifos

Organophosphate (OP) pesticides, including chlorpyrifos (CPF), can alter metabolic hemostasis. The current systematic study investigated blood glucose, lipid profiles, and body weight alterations in rodents and fish exposed to CPF. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Guidelines, querying online databases, including Web of Science, PubMed, and Scopus and also search engine including Google Scholar, through January 2021. Studies on rodent and fish exposed to CPF assessing metabolic functions were selected. All studies were in the English language, with other languages being excluded from the review. Two investigators independently assessed each of the articles. The first author's name, publication date, animal model, age, sample size, gender, dose, duration, and route of exposure and outcomes were extracted from each publication. The present review summarizes findings from 61 publications on glycemic, lipid profile, insulin, and body weight changes in rodents and fish exposed to CPF exposure. Most of the studies reported hyperglycemia, hyperlipidemia, and decreased insulin levels and body weight following exposure to CPF. Additionally, we confirmed that the CPF-induced metabolic alterations were both dose- and time-dependent. Our findings support an association between CPF exposure and metabolic diseases. However, more studies are needed to identify the metabolic-disrupting effects of CPF and their underlying mechanisms.

A comprehensive review on chlorpyrifos toxicity with special reference to endocrine disruption: Evidence of mechanisms, exposures and mitigation strategies

Chlorpyrifos (CPF) is a broad-spectrum chlorinated organophosphate (OP) pesticide used for the control of a variety of insects and pathogens in crops, fruits, vegetables, as well as households, and various other locations. The toxicity of CPF has been associated with neurological dysfunctions, endocrine disruption, and cardiovascular diseases (CVDs). It can also induce developmental and behavioral anomalies, hematological malignancies, genotoxicity, histopathological aberrations, immunotoxicity, and oxidative stress as evidenced by animal modeling. Moreover, eye irritation and dermatological defects are also reported due to CPF toxicity. The mechanism of action of CPF involves blocking the active sites of the enzyme, acetylcholinesterase (AChE), thereby producing adverse nervous system effects. Although CPF has low persistence in the body, its active metabolites, 3,5,6-trichloro-2-pyridinol (TCP), and chlorpyrifos-oxon (CPO) are comparatively more persistent, albeit equally toxic, and thus produce serious health complications. The present review has been compiled taking into account the work related to CPF toxicity and provides a brief compilation of CPF-induced defects in animals and humans, emphasizing the abnormalities leading to endocrine disruption, neurotoxicity, reproductive carcinogenesis, and disruptive mammary gland functionality. Moreover, the clinical signs and symptoms associated with the CPF exposure along with the possible pharmacological treatment are reported in this treatise. Additionally, the effect of food processing methods in reducing CPF residues from different agricultural commodities and dietary interventions to curtail the toxicity of CPF has also been discussed.

Effects of chlorpyrifos exposure on liver inflammation and intestinal flora structure in mice

Chlorpyrifos (CPF) is an organophosphate insecticide commonly used to treat fruit and vegetable crops. CPF can cause severe adverse effects on body organs including the liver and central nervous system. This study investigated the CPF-induced inflammation in mice and explored the role of intestinal flora changes in liver inflammation. Adult C57BL/6 male mice were exposed to a CPF of 0.01-, 0.1-, 1- and 10-mg/kg bodyweight for 12 weeks. The mice in experimental group given CPF solution dissolved in corn oil vehicle by gavage, was administered by intraoral gavage for 5 days per week for 12 weeks. Histopathological examination and inflammatory factor detection were performed on mice liver tissue. Faeces were used for 16S ribosomal RNA high-throughput sequencing to explore the impact of CPF on intestinal flora structure and diversity. The results showed that 1- and 10-mg/kg CPF caused different degrees of liver focal inflammation. The structure of intestinal flora changed significantly in mice including the decreased beneficial bacteria (Akkermansia, Prevotella and Butyricimonas) and increased pathogenic bacteria (Helicobacter and Desulfovibrio). Meanwhile, the results of Q-RT-PCR showed that there was more total bacterial DNA in the liver tissue of the mice treated with 10-mg/kg groups. In conclusion, the imbalance of intestinal flora, the decreased abundance of beneficial bacteria and the increased abundance of pathogenic bacteria, as well as the increase of total bacterial DNA in the liver tissues, maybe associated with the liver focal inflammation induced by CPF.

Chlorpyrifos Induces Metabolic Disruption by Altering Levels of Reproductive Hormones

Chlorpyrifos (CPF) is a widely used organophosphorus pesticide and detected frequently in fruits, vegetables, as well as in urine and blood in humans. Studies have suggested that CPF can induce metabolic disruption, such as type-2 diabetes mellitus and changed body weight. The main mechanisms are based on oxidative damage, fatty-acid synthesis, and lipid peroxidation. Studies have also shown that CPF can change reproductive hormone (RH) levels. CPF might result in metabolic disorders through altered RH levels. Here, we review the studies showing that CFP causes metabolic disruption. Then, we present the studies showing that CFP changes RH levels. Finally, we discuss a potential pathway of how CPF elicits metabolic disruption.

Chlorpyrifos Induction of Testicular-Cell Apoptosis through Generation of Reactive Oxygen Species and Phosphorylation of AMPK

Chlorpyrifos (CPF) is the most frequently applied insecticide. Aside from effects on the neuronal cholinergic system, previous studies suggested a potential relationship between CPF exposure and male infertility; however, the molecular mechanism remains elusive. The aim of this study was to investigate the toxic effect of CPF on testicular cells and the potential mechanism via in vitro and in vivo experiments. The cytotoxic effects of CPF on mouse-derived spermatogonial cell lines (GC-1), Sertoli cell lines (TM4) and Leydig cell lines (TM3) were assessed by a CCK-8 assay, flow cytometry, a TUNEL assay, quantitative RT-PCR, and Western blotting. Exposure to CPF (10-50 μM) for 12 or 24 h resulted in significant death in all three testicular cell lines. The number of TUNEL-positive apoptotic cells were dose-dependent and increased with raised CPF concentrations. Further investigation indicated that CPF induced cell-cycle arrest and then promoted cell apoptosis. Additionally, CPF increased reactive-oxygen-species (ROS) production and lipid peroxidation (MDA) and reduced mitochondrial-membrane potential. The mechanism of cell apoptosis induced by CPF involved an increase in phosphorylated-AMP-activated-protein-kinase (p-AMPK) levels in the tested cells. In vivo, the expression of steroid-hormone-biosynthesis-related genes in testis, spleen, and lung in F0 and F1 mice were downregulated when there was intraperitoneal injection or dietary supplementation of CPF. This study provides a potential molecular mechanism of CPF-induced toxicity in testicular cells and a theoretical basis for future treatment of male infertility.

Alpha lipoic acid protects against chlorpyrifos-induced toxicity in Wistar rats via modulating the apoptotic pathway

The chronic exposure to chlorpyrifos (CPF) pesticide induces several human disorders including hepatotoxicity. Alpha-lipoic acid (ALA) is a natural antioxidant compound found in plants and animals. The present study aimed to investigate the possible protective effect of ALA against CPF-induced hepatotoxicity and the possible underlying molecular mechanism. Thirty-two male Wistar rats were divided into: Normal rats received only vehicle; ALA group received ALA (10 mg/kg, i.p.); CPF group received CPF (18 mg/kg, s.c.) and CPF-ALA group received CPF (18 mg/kg, s.c.) once daily for 14 days. The present results demonstrated that administration of ALA significantly improved liver functions (p < 0.05) and limited the histopathological lesions induced by CPF in liver tissues. Furthermore, ALA decreased hepatic malondialdehyde contents while increased the glutathione peroxidase, catalase, superoxide dismutase and acetylcholinesterase activities. Interestingly, ALA showed significant antiapoptotic effects through downregulation of Bax and Caspase-3 expression levels. In conclusion, ALA possess protective effects against CPF-induced liver injury through attenuation of apoptosis and oxidative stress.

Epidemiology of and Risk Factors for Type 2 Diabetes in Egypt

BACKGROUND

Diabetes is a fast-growing health problem in Egypt with a significant impact on morbidity, mortality, and health care resources. Currently, the prevalence of type 2 diabetes (T2D) in Egypt is around 15.6% of all adults aged 20 to 79.

OBJECTIVE

To describe the epidemiology, principal causes, associated risk factors, cultural aspects, and challenges that may contribute to the rapid rise in T2D in Egypt.

METHODS

Review of papers in PubMed and relevant gray literature.

FINDINGS

The International Diabetes Federation (IDF) has identified Egypt as the ninth leading country in the world for the number of patients with T2D. The prevalence of T2D in Egypt was almost tripled over the last 2 decades. This sharp rise could be attributed to either an increased pattern of the traditional risk factors for T2D such as obesity and physical inactivity and change in eating pattern or other risk factors unique to Egypt. These include increased exposure to environmental risk factors like pesticides and increased prevalence of chronic hepatitis C.

CONCLUSIONS

Prevention, early identification, and effective intervention are integral components of effective T2D care in Egypt. These strategies may reduce the expanding economic burden associated with T2D care.

Protective effect of thymoquinone against diazinon-induced hematotoxicity, genotoxicity and immunotoxicity in rats

Several studies have shown that oxidative stress and cell damage can occur in the very early stages of diazinon (DZN) exposure. The present study was designed to determine the beneficial effect of thymoquinone (Thy), the main component of Nigella sativa (black seed or black cumin) against DZN immunotoxicity, hematotoxicity and genotoxicity in rats. In the present experimental study, 48 male Wistar rats were randomly divided into six groups, (eight per group) as follows: control (receiving corn oil as the DZN solvent), DZN (20mg/kg), Thy (10mg/kg), Thy (2.5mg/kg)+DZN, Thy (5mg/kg)+DZN and Thy (10mg/kg)+DZN. After four weeks of treatment, the hematological parameters of red blood cells (RBCs), white blood cells (WBCs), hemoglobin (Hb), hematocrit (Hct) and platelets (PLTs) were evaluated. The evaluation of genotoxicity was carried out using the micronucleus assay. For measurement of cytokine production, interferon gamma (IFN-γ), interleukin 10 (IL10) and interleukin 4 (IL4) were chosen as immunotoxicity indicators of DZN toxicity. DZN was found to decrease RBCs, WBCs, Hb, Hct, PLTs, butyrl- and acetyl-cholinesterase activity and I FN-γ and increased the micronucleus indices of IL10 and IL4 as compared with the control group. Treatment with Thy reduced DZN hematotoxicity and immunotoxicity, but, significantly, did not prevent genotoxicity. This study showed that Thy (without the significant effect on genotoxicity) decreased the hematological toxicity, immunotoxicity and butyrl and acetyl cholinesterase activity induced by DZN. The success of Thy supplementation against DZN toxicity can be attributed to the antioxidant effects of its constituents.

Cadmium and chlorpyrifos inhibit cellular immune response in spleen of rats

Cadmium (Cd) and chlorpyrifos (CPF) are common pollutants coexisting in the environment, and both of them have been reported to have immunotoxicity to organisms. However, the joint effects of these two chemicals on the immune system are still unknown. In this study, we used CdCl₂ and CPF to study their combined effects on immune functions in the spleen of rats. In in vivo experiments, SD rats were exposed to different doses of CdCl₂ (0.7 and 6 mg kg^-1 body weight/day) and CPF (1.7 and 15 mg kg^-1 body weight/day) or their combinations for consecutive 28 days. The proliferation and cytokine production ability of the splenocytes isolated from the treated animals were assessed. In in vitro experiments, we used different concentrations of CdCl₂ and CPF to treat concanavalin A (Con A)-induced splenocytes isolated from untreated rats. We found that the combination of CPF and high dose of CdCl₂ had a synergistic inhibitory effect on production of IFN-γ by spleen cells induced by Con A. The in vitro results showed that two chemicals had different effects on the cell proliferation and cytokine production depending on the exposure doses and time. This result suggests that exposure to both CdCl₂ and CPF at the environmentally-relevant low dose may be potentially more hazardous than exposure to each individual toxicant.

Protective effects of green tea and its main constituents against natural and chemical toxins: A comprehensive review

Toxins are natural or chemical poisonous substances with severe side effects on health. Humans are generally exposed by widespread toxic contaminations via air, soil, water, food, fruits and vegetables. Determining a critical antidote agent with extensive effects on different toxins is an ultimate goal for all toxicologists. Traditional medicine is currently perceived as a safe and natural approach against toxins. In this regard, we focused on the protective effects of green tea (Camellia sinensis) and its main components such as catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin and epigallocatechin gallate as a principal source of antioxidants against both natural and chemical toxins. This literate review demonstrates that protective effects of green tea and its constituents were mainly attributed to their anti-oxidative, radical scavenging, chelating, anti-apoptotic properties and modulating inflammatory responses. Although, some studies reveal they have protective effects by increasing toxin metabolism and neutralizing PLA₂, proteases, hyaluronidase and l-amino acid oxidase enzymes.

Arsenic and dichlorvos: Possible interaction between two environmental contaminants

Metals are ubiquitously present in the environment and pesticides are widely used throughout the world. Environmental and occupational exposure to metal along with pesticide is an area of great concern to both the public and regulatory authorities. Our major concern is that combination of these toxicant present in environment may elicit toxicity either due to additive or synergistic interactions or 'joint toxic actions' among these toxicants. It poses a rising threat to human health. Water contamination particularly ground water contamination with arsenic is a serious problem in today's scenario since arsenic is associated with several kinds of health problems, such arsenic associated health anomalies are commonly called as 'Arsenism'. Uncontrolled use and spillage of pesticides into the environment has resulted in alarming situation. Moreover serious concerns are being addressed due to their persistence in the environmental matrices such as air, soil and surface water runoff resulting in continuous exposure of these harmful chemicals to human beings and animals. Bio-availability of these environmental toxicants has been enhanced much due to anthropological activities. Dreadfully very few studies are available on combined exposures to these toxicants on the animal or human system. Studies on the acute and chronic exposure to arsenic and DDVP are well reported and well defined. Arsenic is a common global ground water contaminant while dichlorvos is one of the most commonly and widely employed organophosphate based insecticide used in agriculture, horticulture etc. There is thus a real situation where a human may get exposed to these toxicants while working in a field. This review highlights the individual and combined exposure to arsenic and dichlorvos on health.

Characterization of the interaction between cadmium and chlorpyrifos with integrative techniques in incurring synergistic hepatoxicity

Mixture toxicity is an important issue for the risk assessment of environmental pollutants, for which an extensive amount of data are necessary in evaluating their potential adverse health effects. However, it is very hard to decipher the interaction between compounds due to limited techniques. Contamination of heavy metals and organophosphoric insecticides under the environmental and biological settings poses substantial health risk to humans. Although previous studies demonstrated the co-occurrence of cadmium (Cd) and chlorpyrifos (CPF) in environmental medium and food chains, their interaction and potentially synergistic toxicity remain elusive thus far. Here we integrated the approaches of thin-layer chromatography and (1)H NMR to study the interaction between Cd(2+) and CPF in inducing hepatoxicity. A novel interaction was identified between Cd(2+) and CPF, which might be the bonding between Cd(2+) and nitrogen atom in the pyridine ring of CPF, or the chelation formation between one Cd(2+) and two CPF molecules. The Cd-CPF complex was conferred with distinct biological fate and toxicological performances from its parental components. We further demonstrated that the joint hepatoxicity of Cd ion and CPF was chiefly due to the Cd-CPF complex-facilitated intracellular transport associated with oxidative stress.

Toxic impact of two organophosphate insecticides on biochemical parameters of a food fish and assessment of recovery response

Sublethal effects of chlorpyrifos (CPF) and monocrotophos (MCP) on fish biochemical constituents were investigated along with the assessment of recovery response after cessation of intoxication. The fish, Clarias batrachus were exposed to 1.656 mg–l and 2.114 mg–l of CPF and MCP for 28 days. After 28 days, they were released in freshwater and allowed to recover for 21 days. The CPF exposure resulted in the decrease of carbohydrate and glycogen content, whereas MCP intoxication caused mixed response. Pyruvate and lactate contents were altered under the stress of CPF and MCP. Recovery of these alterations was observed after the cessation of toxicity. Exposure of C. batrachus to CPF and MCP resulted in decreased activity of lactate dehydrogenase in the kidney, liver and muscle but its activity increased in the gills. The CPF caused inhibition of succinate dehydrogenase enzyme in all tissues. Induction in the activity of malate dehydrogenase was caused by both insecticides. Glycogen phosphorylase a was induced in all tissues, whereas glycogen phosphorylase ab showed both induction and inhibition. Of the two insecticides, CPF was more toxic and the recovery response was less. These results are important in the assessment of the risk caused by organophosphate insecticides on nontarget organisms, especially the food fish.

Uptake and retention of 65Zn in lithium-treated rat liver: role of zinc

AIM

To evaluate the effects of zinc on the biokinetics of (65)Zn in rat and its distribution in various organs and in subcellular compartment following lithium therapy.

METHODS

Female wistar rats received either lithium treatment at a dose of 1.1g/kg in diet, zinc alone at a dose of 227 mg/L in drinking water, and combined lithium plus zinc for duration of four months.

RESULTS

After four months of lithium treatment, liver enzymes increased significantly (glutamic oxaloacetic transaminase, +66.73%; glutamic pyruvic transaminase, +63.70%; alkaline phosphatase, +40.28%; p< or =0.001); zinc supplementation to lithium-treated rats significantly reduced liver enzymes (glutamic oxaloacetic transaminase, -13.11%; glutamic pyruvic transaminase, -21.78%; alkaline phosphatase, -11.77%; p< or =0.001). The biological half-lives of (65)Zn showed an initial fast component (Tb(1)) and a slower component (Tb(2)). A significant increase in Tb(2) (38.82%, p< or =0.001) in liver was observed following lithium treatment, which significantly decreased following zinc treatment (21.71%, p< or =0.001). A significant decrease in the uptake of (65)Zn (53.93%, p< or =0.01) in liver was observed and in nuclear (p< or =0.01), mitochondrial (p< or =0.01), and microsomal (52.67%, p< or =0.001) fractions. A significant increase in the uptake of (65)Zn (82.92%, p< or =0.05) in liver microsomal fraction (34.09%, p< or =0.001) was observed in lithium-treated rats receiving zinc supplementation.

CONCLUSION

The study suggests that zinc has the potential to regulate the biokinetics of (65)Zn and its subcellular distribution in rat liver following lithium therapy.

Enzymes as biomarkers of cypermethrin toxicity: response of Clarias batrachus tissues ATPase and glycogen phosphorylase as a function of exposure and recovery at sublethal level

The present study was conducted to evaluate the sublethal effects of a synthetic pyrethroid, cypermethrin on ATPase, and glycogen phosphorylase in gill, kidney, liver, and muscle tissue of freshwater fish, Clarias batrachus (Linn) during exposure and cessation of exposure. Thirty-six fish were exposed to 1/3 of LC 50 concentration i, e. 0.07 mg/L cypermethrin for 10 days. After 10 days, 18 fish were transferred to freshwater and 10 days recovery response was observed. Thirty-six fish were kept as a control group. The effect of cypermethrin intoxication was studied on total, Mg(+2), Na(+)-K(+) ATPase, glycogen, and glycogen phosphorylase (a) and (ab) in various physiological tissues at the end of 1, 5, and 10 days of exposure and recovery period. Cypermethrin intoxication resulted in a significant inhibition in the activities of total, Mg(+2), and Na(+)-K(+) ATPase enzyme and glycogen content, whereas it caused a significant induction in the levels of glycogen phosphorylase (a). The activity level of glycogen phosphorylase (ab) showed mixed response. When exposed fish were released into freshwater, they were able to normalize the activities of ATPase enzyme in liver tissue whereas gill, kidney, and muscle tissues showed slight recovery. At the end of 10 days of recovery period, glycogen and glycogen phosphorylase activities in kidneys recover better than muscle. Therefore, the present study clearly suggests that ATPase and glycogen phosphorylase enzymes can be used as biomarkers of exposure to aquatic organisms under cypermethrin intoxication.

Effectiveness of zinc in modulating lithium induced biochemical and behavioral changes in rat brain

1. The purpose of the present study was to determine the effect of zinc on the status of various neurotransmitters as well as behavioral patterns of lithium-treated rats. The study was designed with a view to find out whether zinc affords protection to brain against lithium toxicity. 2. Animals were segregated into four different groups. Animals in group I were fed with standard laboratory feed and water ad libitum and served as normal controls. Animals in group II and IV were given lithium in the form of lithium carbonate in their diet at a dose level of 1.1 g/Kg diet. Animals in group III and IV were given zinc treatment in the form of zinc sulfate at a dose level of 227 mg/L mixed in drinking water of animals. 3. The effects of all the treatments were studied for a duration of 1, 2, and 4 months with regard to the parameters, which included estimation of serotonin and dopamine concentrations as well as the activity of acetylcholinesterase in cerebral cortex of rat brain. Further, passive avoidance, active avoidance, and behavior despair tests were conducted to assess the short-term memory, cognitive behavior, and psychomotor dysfunction of the animals, respectively. 4. Initially, a decrease in the acetylcholinesterase activity was reported in cerebral cortex followed by an increase in the enzyme activity after 2 and 4 months of lithium treatment. Serotonin concentration significantly decreased after 2 and 4 months of lithium treatment, whereas dopamine concentration increased significantly after 4 months of lithium treatment. Zinc administration to the lithium-treated group significantly improved the acetylcholinesterase activity as well as the concentration of dopamine and serotonin. Further, lithium-treated rats showed an increase in depression time as compared to normal controls both after 1 and 4 months of treatment. Short-term memory significantly improved in lithium-treated rats in all treatment groups. However, no change in the cognitive behavior of the animals was reported after lithium treatment. Zinc co-administration with lithium significantly improved the short-term memory and cognitive functions of the animals. From the above results it can be concluded that zinc proved beneficial in altering the status of neurotransmitters as well as the behavior patters of the animals treated with both short and long-term lithium therapy.