Effects of chronic diazepam exposure on the behaviors and oxidative stress homeostasis in the eyes and brains of female Japanese medaka

Diazepam (DZP) residue has been frequently detected in wastewater, surface water, and groundwater due to its extensive use over the decades. In this study, we exposed female Japanese medaka (Oryzias latipes) to environmentally relevant doses of DZP (800 and 8000 ng/L) for 4 weeks, aimed to investigate their behavioral responses and possible links with ocular and brain oxidative stress homeostasis. As a result, DZP exposure could significantly reduce swimming activity (800 ng/L) and anxiety (800 and 8000 ng/L), indicating a sedative effect on medaka. The DZP exposure also significantly increased the social interaction in medaka at 8000 ng/L. Furthermore, exposure to DZP could alter the ocular and brain oxidative stress homeostasis in medaka. The ocular CAT activities significantly increased in the 800 ng/L-DZP groups, and the brain SOD, CAT, GST and MDA levels also significantly increased in both DZP exposure groups. Correlation analysis revealed that the ocular and brain oxidative stress induced by DZP exposure might play an important role in their behavioral toxicity to medaka. Our findings highlight the necessity to clarify the exact link between DZP exposure-induced oxidative stress in the neural and sensor systems and its behavioral toxicity to better assess the risks on nontarget aquatic species.

Prenatal effects of alprazolam treatment on the immature cerebellum of rats

The use of benzodiazepines (BZDs) during pregnancy, especially alprazolam, is common and its impact on the fetal neural tissue is not known. In this sense, the present study aimed to investigate the effects of prenatal treatment with alprazolam on the cerebellum of Wistar rat pups. Thirty animals (24 females and six males, CEUA protocol 014/17) were separated into pairs for copulation. Females were divided into three groups: Control (CT), treatment 1 (T1, 1.25 mg per animal), and treatment 2, which is an overdose (T2, 30 mg per animal). Alprazolam was administered 10 days before copulation and throughout pregnancy. We evaluated the number and weight of pups and the macroscopic changes in the brain. Eight neonates (n = 8) from each group were used in the following analyses: Cellular and chromatin density, gliosis, synaptic density, inflammation, and oxidative stress. The results showed no significant differences regarding the number of pups, body weight, and macroscopic changes. The morphological study focused on the external granular layer (EGL) that is presented only in the immature cerebellum. Here, we detected more cells after alprazolam treatment; the T2 group showed large nuclei and some pyknotic nuclei; also, both treated groups presented an increase in the euchromatin density compared with the control. The molecular and biochemical analyses used the total protein extract of the entire cerebellum and showed an increased expression of Iba-1 and NF-κBp65 but without indication of inflammation or degeneration in the T1 group. Overdose of alprazolam presented an increased level of oxidative degradation of lipids. The treatment with alprazolam during pregnancy involved cellular and molecular changes in the immature cerebellum.

Toxicological outcome of exposure to psychoactive drugs carbamazepine and diazepam on non-target insect Nauphoeta cinerea

The continuous detection of human pharmaceuticals during environmental biomonitoring is a global concern because of the menaces they may exert on non-target organisms. Carbamazepine (CBZ) and diazepam (DZP) are commonly prescribed psychotropic drugs which have been reported to coexist in the environment globally. Nauphoeta cinerea is a common insect with high ecological impact. This study elucidated the influence of co-exposure to DZP (0.5 and 1.0 μg kg^-1 diet) and CBZ (1.5 and 3.0 μg kg^-1 diet) for 42 days on the behavior and biochemical responses in Nauphoeta cinerea. Results showed that DZP alone did not induce adverse effect on the behavior and antioxidant status in the exposed insects. However, exposure to CBZ alone and binary mixtures of DZP and CBZ significantly decreased locomotor and exploratory accomplishments evidenced by decreased mobile episodes, total mobile time, maximum speed, total distance traveled, absolute turn angle, body rotation and path efficiency in comparison with control. The decline observed in the exploratory activities of insects fed with CBZ alone and the mixtures was confirmed by track plots and heat maps. Further, acetylcholinesterase and antioxidant enzyme activities decreased significantly whereas reactive oxygen and nitrogen species, nitric oxide and lipid peroxidation levels increased significantly in the hemolymph, head and midgut of insects exposed to CBZ alone and the mixtures. Collectively, CBZ alone and binary mixtures of CBZ and DZP caused neurotoxicity via induction of inflammatory and oxidative stress in insects. Nauphoeta cinerea may be a potential non-target insect model for monitoring ecotoxicological hazard of pharmaceuticals.

Acute and chronic effects of diazepam on the polychaete Hediste diversicolor: Antioxidant, metabolic, pharmacologic, neurotoxic and behavioural mechanistic traits

Pharmaceutical drugs are widespread environmental contaminants, but data about their adverse effects are still limited to a few compounds. This study analyzed the acute (96 h) and chronic (28 days) impacts of environmentally realistic levels of diazepam (acute exposure: 0.001, 0.01, 0.1, 1, 10 μg/L; chronic exposure: 0.1, 1, 10, 100, 1000 ng/L), in the polychaete Hediste diversicolor, by measuring behavioral and biochemical (catalase [CAT], glutathione-S-transferases [GSTs], cholinesterases [ChEs], glutathione peroxidase [GPx], lipid peroxidation [TBARS]) parameters. Acute exposure to diazepam altered behavioral traits, decreasing burrowing times and causing hyperactivity, whilst burrowing time increased and hypoactivity resulted after chronic exposure. All biomarkers were affected after the chronic exposure, with the exception of lipid peroxidation. Our data demonstrate that realistic levels of diazepam may impair behavioral and biochemical traits in polychaetes, suggesting that diazepam exposure presents a significant challenge to the environment that supports these organisms.

Effects of sodium benzoate, a commonly used food preservative, on learning, memory, and oxidative stress in brain of mice

Sodium benzoate (SB) is a widely used preservative and antimicrobial substance in many foods and soft drinks. However, this compound is generally recognized as safe food additives, but evidence has suggested that a high intake of SB may link to attention deficit-hyperactivity disorder in children. Present study investigate the effects of oral administration of different concentrations of SB (0.56, 1.125, and 2.25 mg/mL) for 4 weeks, on the learning and memory performance tests, and also the levels of malondialdehyde (MDA), reduced glutathione (GSH), and acetylcholinesterase activity (AChE) in the mouse brain. The results showed that SB significantly impaired memory and motor coordination. Moreover, SB decreased reduced GSH and increased the MDA level in the brain significantly (P < 0.001). However, nonsignificant alteration was observed in the AChE activity. These findings suggest that short-term consumption of SB can impair memory performance and increased brain oxidative stress in mice.

Curcumin Reverses the Diazepam-Induced Cognitive Impairment by Modulation of Oxidative Stress and ERK 1/2/NF-κB Pathway in Brain

Oxidative stress and inflammation can be involved in cognitive dysfunction associated with neurodegenerative disorders. Diazepam (DZP) administration has been chosen to simulate the memory impairment. The aim of this study was to evaluate the effects of curcumin (CUR) on spatial cognition, ambulatory activity, and blood and brain oxidative stress levels. The ERK/NF-κB signaling pathway and the histopathological changes in the hippocampus and frontal lobe, in diazepam-treated rats, were also analyzed. The animals were divided into 4 groups: control, carboxymethylcellulose (CMC) + CUR, CMC + DZP, and CUR + CMC + DZP. CUR (150 mg/kg b.w.) was orally administered for 28 days. DZP (2 mg/kg b.w.) was intraperitoneally administered 20 minutes before the behavioral tests (open field test, Y-maze, and elevated plus maze). CUR improved the spontaneous alternation behavior, decreased the oxidative stress levels, both in the blood and in the hippocampus, and downregulated the extracellular signal-regulated kinase (ERK 1/2)/nuclear transcription factor- (NF-) κB/pNF-κB pathway in the hippocampus and the iNOS expression in the hippocampus and frontal lobe of the DZP-treated rats. Histopathologically, no microscopic changes were found. The immunohistochemical signal of iNOS decreased in the DZP and CUR-treated group. Thus, our findings suggest that curcumin administration may improve the cognitive performance and may also have an antioxidant effect.

Low dose X-irradiation mitigates diazepam induced depression in rat brain

Depression is considered as one of the most prevalent health ailments. Various anti-depressant drugs have been used to provide succour to this ailment, but with little success and rather have resulted in many side effects. On the other hand, low dose of ionizing radiations are reported to exhibit many beneficial effects on human body by stimulating various biological processes. The present study was conducted to investigate the beneficial effects of low doses of X-rays, if any, during diazepam induced depression in rats. Female Sprague Dawley rats were segregated into four different groups viz: Normal control, Diazepam treated, X-irradiated and Diazepam + X-irradiated. Depression model was created in rats by subjecting them to diazepam treatment at a dosage of 2 mg/kg b.wt./day for 3 weeks. The skulls of animals belonging to X-irradiated and Diazepam + X-irradiated rats were X-irradiated with a single fraction of 0.5 Gy, given twice a day for 3 days, thereby delivered dose of 3 Gy. Diazepam treated animals showed significant alterations in the neurobehavior and neuro-histoarchitecture, which were improved after X-irradiation. Further, diazepam exposure significantly decreased the levels of neurotransmitters and acetylcholinesterase activity, but increased the monoamine oxidase activity in brain. Interestingly, X-rays exposure to diazepam treated rats increased the levels of neurotransmitters, acetylcholinesterase activity and decreased the monoamine oxidase activity. Further, depressed rats also showed increased oxidative stress with altered antioxidant parameters, which were normalized on X-rays exposure. The present study, suggests that low dose of ionizing radiations, shall prove to be an effective intervention and a novel therapy in controlling depression and possibly other brain related disorders.