Histopathological and immunohistochemical study of the protective effect of triptorelin on the neurocytes of the hippocampus and the cerebral cortex of male albino rats after short-term exposure to cyclophosphamide

Investigation of the effects of curcumin and piperine on cyclophosphamide-induced brain injury in rats

Cyclophosphamide (CP) is an antineoplastic drug widely used in chemotherapy. Curcumin (CUR) and piperine (PP) show a protective effect on neurodegenerative and neurological diseases. This research was designed to measure several biochemical parameters in the brain tissue of CP-applied rats to investigate the impact of combined CUR-PP administration. The study evaluated six groups of eight rats: Group 1 was the control; Groups 2 and 3 were administered 200 or 300 mg/kg CUR-PP via oral gavage; Group 4 received only 200 mg/kg CP on day 1; Groups 5 and 6 received CP + CUR-PP for 7 days. Data from all parameters indicated that CP caused brain damage. Phosphorylated TAU (pTAU), amyloid-beta peptide 1-42 (Aβ1-42), glutamate (GLU), and gamma amino butyric acid (GABA) parameters were the same in Groups 4, 5, and 6. On the other hand, 8-hydroxy-2-deoxyguanosine (8-OHdG), nitric oxide (NO), interleukin-6 (IL-6), nuclear factor kappa beta (NF-kβ), malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-α) levels in the CP + CUR-PP groups were lower than those in the CP group (p < 0.05). However, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) parameters were higher in the CP + CUR-PP groups compared to the CP group (p < 0.05). It is thought that the similarity of Groups 5 and 6 with Group 4 in Aβ1-42, pTAU, GLU, and GABA parameters hinder the determination of treatment protection however, they might have a therapeutic effect if the applied dose or study duration were changed. This study attempted to evaluate the effects of a CUR-PP combination on CP-induced brain damage in rats by measuring biochemical parameters and performing histopathological examinations. Based on the findings, this CUR-PP combination could be considered an alternative medicine option in cases with conditions similar to those evaluated in this study.

Molecular mechanisms underlying cyclophosphamide-induced cognitive impairment and strategies for neuroprotection in preclinical models

Cyclophosphamide has drastically enhanced the expectancy and quality of life of cancer patients. However, it is accompanied by diverse neurological complications which are considered a dose-limiting adverse effect. Neurotoxicity caused by cyclophosphamide can manifest in numerous manners including anxiety, depression, motor dysfunction and cognitive deficits. This review article offers an overview on cyclophosphamide-induced neurotoxicity, providing a unified point of view on the possible underlying molecular mechanisms including oxidative brain damage, neuroinflammation, apoptotic neuronal cell death as well as disruption of the balance of brain neurotransmitters and neurotrophic factors. Besides, this review sheds light on the promising protective agents that have been investigated using preclinical animal models as well as their biological targets and protection mechanisms. Despite promising results in experimental models, none of these agents has been studied in clinical trials. Thus, there is lack of evidence to advocate the use of any neuroprotective agent in the clinical setting. Furthermore, none of the protective agents has been evaluated for its effect on the anticancer activity of cyclophosphamide in tumor-bearing animals. Therefore, there is a great necessity for adequate well-designed clinical studies for evaluation of the therapeutic values of these candidates. Conclusively, this review summarizes the molecular mechanisms accounting for cyclophosphamide-induced neurotoxicity together with the potential protective strategies seeking for downgrading this neurological complication, thus enhancing the quality of life and well-being of cancer patients treated with cyclophosphamide.

Protective effects of hesperidin in cyclophosphamide-induced parotid toxicity in rats

Cyclophosphamide (CYP) is an alkylating agent that is used on a wide range as a treatment of malignancies and autoimmune diseases. Previous studies have shown the promising role of hesperidin (HSP) as an antioxidant agent against various models of toxic agents. The protective effect of the HSP against CYP-induced parotid damage was evaluated in this study. Forty rats (180-200 g) were divided into four equal groups: Group I (received normal saline), Group II (HSP-treated at a dose of 100 mg/kg/day for 7 consecutive days), Group III (CYP-treated at a dose of 200 mg/kg single intraperitoneal injection on the 7th day of the experiment), Group IV (CYP + HSP); HSP-treated at a dose of 100 mg/kg/day for 7 consecutive days and CYP (200 mg/kg) single intraperitoneal injection on the 7th day of the experiment. Afterwards, the oxidative stress and inflammatory markers, the histopathological and immunohistochemical alterations of the parotid tissues in the studied groups were evaluated. CYP intoxication induced a significant parotid tissue injury represented by the elevation in the values of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and decrease in the catalase activity and glutathione peroxidase (GPx). Histologically, extensive histopathological alterations e.g., widely spaced serous acini with irregular shapes and congested blood vessels as well as downregulated ki-67 and alpha-smooth muscle actin (α-SMA) immunoexpression were induced by CYP. HSP administration markedly improved the biochemical and the histopathological studies. We can conclude that HSP elicited protective effects against the CYP-induced parotid toxicity.

Lutein isolated from Scenedesmus obliquus microalga boosts immunity against cyclophosphamide-induced brain injury in rats

Lutein is a naturally potent antioxidant carotenoid synthesized in green microalgae with a potent ability to prevent different human chronic conditions. To date, there are no reports of the immune-stimulating effect of pure lutein isolated from Scenedesmus obliquus. Thus, we isolated the natural lutein from S. obliquus and evaluated its effectiveness as an immunostimulant against cyclophosphamide-induced brain injury. We purified all-E-(3R, 3'R, 6'R)-Lutein from S. obliquus using prep-HPLC and characterized it by ¹H- and ¹³C-NMR spectroscopy. We assigned rats randomly to four experimental groups: the Control group got a vehicle for lutein dimethyl sulfoxide for ten successive days. The Cyclophosphamide group received a single i.p injection of Cyclophosphamide (200 mg/kg). Lutein groups received 50 and 100 (mg/kg) of lutein one time per day for ten successive days after the cyclophosphamide dose. Lutein administration reduced brain contents of Macrophage inflammatory protein2 (MIP2), cytokine-induced- neutrophil chemoattractant (CINC), and Matrix metalloproteinase 1 (MMP1). Besides, it lowered the contents of interleukin 1 beta (IL-1β) and interleukin 18 (IL-18), associated with low content of NLR pyrin domain protein 3 (NLRP3) and consequently caspase-1 compared to the cyclophosphamide group. In the histomorphometric analysis, lutein groups (50 and 100 mg/Kg) showed mild histopathological alterations as they significantly reduced nuclear pyknosis numbers by 65% and 69% respectively, compared to the cyclophosphamide group. This is the first study that showed the immunomodulatory roles of lutein against cyclophosphamide-induced brain injury via decreasing neuroinflammation, chemokines recruitment, and neuron degeneration with the modulation of immune markers. Hence, lutein can be an effective immunomodulator against inflammation-related immune disorders.

Protective Effects of Intranasally Administrated Oxytocin-Loaded Nanoparticles on Pentylenetetrazole-Kindling Epilepsy in Terms of Seizure Severity, Memory, Neurogenesis, and Neuronal Damage

Pentylenetetrazole (PTZ)-induced kindling is an animal model for studying human temporal lobe epilepsy (TLE), which is characterized by alterations of hippocampal neurons and memory. Although the intranasal (IN) administration of oxytocin (OT) has limited efficiency, nanoparticles (NPs) are a promising candidate to deliver OT to the brain. However, there are very limited data on epilepsy research about oxytocin-loaded nanoparticles (NP-OTs). The aim of this study is to investigate the effects of IN administration of chronic NP-OTs on the hippocampus of PTZ-induced male epileptic rats in terms of seizure severity, memory, neurogenesis, and neuronal damage. Saline/OT/NP-OTs were administrated to both control (Ctrl) and PTZ groups intranasally. Consequently, saline and PTZ were injected, respectively, 25 times every 48 h. Then, seizure severity (score and latency) was calculated for the PTZ groups. A spatial working memory evaluation test (SWMET) was performed after the last injection. Hippocampus histopathology, neurogenesis, and apoptosis were demonstrated. Serum total antioxidant status (TAS) and total oxidant status (TOS) levels and the oxidative stress index (OSI) were measured. We showed that OTs and NP-OTs prevented the kindling development and had positive effects on seizure severity. SWMET-related behaviors were also recovered in the PTZ + NP-OT group. A significant increase of neurogenesis and decrease of apoptosis in the hippocampus of the PTZ + NP-OT group were observed, while OTs and NP-OTs had protective effects against PTZ-induced damage to hippocampal neurons. Our results indicate that the chronic administration of NP-OTs may have positive effects on hippocampal damage via increasing neurogenesis and decreasing apoptosis and seizure severity.

Exercise Normalized the Hippocampal Renin-Angiotensin System and Restored Spatial Memory Function, Neurogenesis, and Blood-Brain Barrier Permeability in the 2K1C-Hypertensive Mouse

Hypertension is associated with blood-brain barrier alteration and brain function decline. Previously, we established the 2-kidney,1-clip (2K1C) hypertensive mice model by renin-angiotensin system (RAS) stimulating. We found that 2K1C-induced hypertension would impair hippocampus-related memory function and decrease adult hippocampal neurogenesis. Even though large studies have investigated the mechanism of hypertension affecting brain function, there remains a lack of efficient ways to halt this vicious effect. The previous study indicated that running exercise ameliorates neurogenesis and spatial memory function in aging mice. Moreover, studies showed that exercise could normalize RAS activity, which might be associated with neurogenesis impairment. Thus, we hypothesize that running exercise could ameliorate neurogenesis and spatial memory function impairment in the 2K1C-hypertension mice. In this study, we performed 2K1C surgery on eight-weeks-old C57BL/6 mice and put them on treadmill exercise one month after the surgery. The results indicate that running exercise improves the spatial memory and neurogenesis impairment of the 2K1C-mice. Moreover, running exercise normalized the activated RAS and blood-brain barrier leakage of the hippocampus, although the blood pressure was not decreased. In conclusion, running exercise could halt hypertension-induced brain impairment through RAS normalization.

Sitagliptin Attenuates the Cognitive Deficits in L-Methionine-Induced Vascular Dementia in Rats

Vascular dementia (VaD) is the second most prevalent type of dementia characterized by progressive cognitive deficits and is a major risk factor for the development of Alzheimer's disease and other neurodegenerative disorders. This study is aimed at determining the potential neuroprotective effect of sitagliptin (STG) on cognitive deficits in L-methionine-induced VaD in rats and the possible underlying mechanisms. 30 adult male Wistar albino rats were divided equally (n = 10) into three groups: control, VaD, and VaD + STG groups. The cognitive performance of the animals was conducted by open field, elevated plus maze, Y-maze, novel object recognition, and Morris water maze tests. Serum homocysteine, TNF-α, IL-6, IL-10, total cholesterol, and triglycerides levels were assessed together with hippocampal MDA, SOD, and BDNF. Histopathological and immunohistochemical assessments of the thoracic aorta and hippocampus (CA1 region) were also performed. Chronic L-methionine administration impaired memory and learning and induced anxiety. On the other hand, STG protected against cognitive deficits through improving oxidative stress biomarkers, inflammatory mediators, lipid profiles, and hippocampus level of BDNF as well as decreasing caspase-3 and GFAP and increasing Ki-67 immunoreactions in the hippocampus. Also, STG improved the endothelial dysfunction via upregulation of aortic eNOS immunoreaction. STG improved the cognitive deficits of L-methionine-induced VaD by its antioxidant, anti-inflammatory, antiapoptotic, and neurotrophic effects. These findings suggest that STG may be a promising future agent for protection against VaD.

Alpha-Lipoic Acid Protects Co-Exposure to Lead and Zinc Oxide Nanoparticles Induced Neuro, Immuno and Male Reproductive Toxicity in Rats

We evaluated the neuro-, immuno-, and male reproductive toxicity of zinc oxide nanoparticles (ZnO NPs) alone and in combination with lead acetate. We also studied the therapeutic role of α-lipoic acid postexposure. Lead (10 mg/kg, body weight), ZnO NPs (100 mg/kg, bwt) alone, and their combination were administered orally in Wistar rats for 28 days, followed by the administration of α-lipoic acid (15 mg/kg, bwt) for the next 15 days. Our results demonstrated protective effects of α-lipoic acid on lead and ZnO NP-induced biochemical alterations in neurological, immunological, and male reproductive organs in rats. The altered levels of blood δ-aminolevulinic acid dehydratase (ALAD), immunoglobulins (IgA, IgG, IgM, and IgE), interleukins (IL-1β, IL-4, and IL-6), caspase-3, and tumor necrosis factor (TNF-α) were attenuated by lipoic acid treatment. Lead and ZnO NP-induced oxidative stress was decreased by lipoic acid treatment, while a moderate recovery in the normal histoarchitecture of the brain section (cortex and hippocampus) and testes further confirmed the neuro- and male reproductive toxicity of lead and ZnO NPs. We also observed a significant decrease in the blood metal content in the animals treated with lipoic acid compared to the lead-administered group, indicating the moderate chelating property of lipoic acid. It may thus be concluded that lipoic acid might be a promising protective agent against lead and ZnO NP-induced alterations in the neurological, immunological, and reproductive parameters.

The effect of glutathione and buserelin on the stereological parameters of the hypothalamus in the cyclophosphamide-treated mice

INTRODUCTION

New anticancer drugs have increased the survival and fertility rates in young patients. These drugs (i.e., cyclophosphamide; Cyc) have some side effects on the hypothalamus and fertility. One possible chemical for reducing these side effects is thiol or GnRH agonist. This study aimed to evaluate the capability of these agents for reducing the cyclophosphamide effects on the hypothalamus.

METHODS

Sixty-three female mice were randomly assigned into seven groups. All groups including the control group had free access to water and mouse chow ad libitum. The sham group received normal saline. The Glu and Bus groups received glutathione (Glu) and buserelin (Bus) daily for 16 days, while the Cyc group received only cyclophosphamide as a single dose; the Cyc + Glu and Cyc + Bus groups, in addition to cyclophosphamide, received glutathione and buserelin, respectively. The volume of the hypothalamus, its neuron number, and dead neurons were evaluated using stereological methods.

RESULTS

There was no significant difference in the evaluated stereological parameters between the control and sham groups. However, the animals which received Cyc showed a decrease in the volume of the hypothalamus and its neuron number and density and an increase in cell death as compared with the control group. The treatment of the mice that received Cyc with Glu or Bus prevented these changes.

CONCLUSION

This study showed that both GnRH agonist and thiol preserved or improved structural changes in the hypothalamus caused by cyclophosphamide in mice, suggesting that using thiol and especially GnRH agonist along with chemotherapy drugs may have protective effects on fertility.

Nanotechnology based blended chitosan-pectin hybrid for safe and efficient consolidative antiemetic and neuro-protective effect of meclizine hydrochloride in chemotherapy induced emesis

The aim of this study was to formulate an easily-administered, safe and effective dosage form loaded with meclizine for treatment of chemotherapy-induced nausea and vomiting (CINV) through the buccal route. CINV comprises bothersome side effects accompanying cytotoxic drugs administration in cancer patients. Meclizine was loaded in chitosan-pectin nanoparticles which were further incorporated within a buccal film. Different formulations were prepared based on a 2¹.3¹ full factorial study using Design Expert®8. The optimum formulation possessed favorable characters regarding its particle size (129 nm), entrapment efficiency (90%) and release profile. Moreover, its permeation efficiency through sheep buccal mucosa was assessed via Franz cell diffusion and confocal laser microscopy methods. Enhanced permeation was achieved compared with the free drug form. In-vivo performance was assessed using cyclophosphamide induced emesis. The proposed formulation exerted significant relief of the measured responses (reduced body weight and motor coordination, elevated emesis, anorexia, proinflammatory mediators and neurotransmitters that were also associated with scattered degenerated neurons and glial cells). The developed formulation ameliorated all behavioral, biochemical and histopathological changes induced by cyclophosphamide. The obtained data were promising suggesting that our bioadhesive formulation can offer an auspicious medication for treating distressing symptoms associated with chemotherapy for cancer patients.