Abstract

Hepatic encephalopathy (HE) is a serious neuropsychiatric syndrome due to either acute or chronic hepatic failure. This study aimed to investigate the possible neuroprotective effect of chrysin, a natural flavenoid on thioacetamide (TAA)-induced hepatic encephalopathy in rats. Also the effect of chrysin on motor impairment, cognitive deficits, oxidative stress, neuroinflammation, apoptosis and histopathological damage was assessed. HE was induced in Wistar rats by intraperitoneal (i.p.) injection of TAA (200?mg/kg) for three alternative days. Normal and control groups received the vehicle for 21 days. Chrysin was administered orally for 21 days (25, 50, 100?mg/kg) and starting from day 17, rats received i.p. dose of TAA (200?mg/kg) at three alternative days. Then behavioral, biochemical, histopathological and immunohistochemical analyses were conducted. Chrysin improved TAA-induced motor incoordination as it reduced final falling latency time in rotarod test, ameliorated cognitive deficits in object recognition test (ORT) and attenuated serum ammonia, hepatic liver enzymes namely, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), reduced malondialdehyde (MDA), elevated reduced glutathione (GSH), reduced nuclear factor kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) brain contents. Chrysin administration also reduced Toll-4 receptor (TLR-4) gene expression, caspase-3 protein expression, hepatic necrosis and astrocyte swelling. This study depicts that chrysin exerted neuroprotective effect in TAA-induced HE rats, evidenced by improvement of cognitive deficits, motor incoordination and histopathological changes such as astrocyte swelling and vacuolization; hallmarks in HE, via reducing hyperammonia, ameliorating hepatic function, in addition to its anti-oxidant, inactivation of TLR-4/NF-κB inflammatory pathway, and anti-apoptotic effects.

Abstract

Background and purpose: Insulin resistance (IR) and obesity predispose diseases such as diabetes, cardiovascular and neurodegenerative disorders. Beta-caryophyllene (BCP), a natural sesquiterpene, exerts neuroprotective, anxiolytic and antidepressant effects via its selective agonism to cannabinoid receptor 2 (CB2R). BCP was shown to have an anti-diabetic effect, however, the implication of CB2R is yet to be elucidated. A link between CB2R agonism and PPAR-γ activation has been discussed, but the exact mechanism is not well-defined. This study was designed to examine the role of BCP in improving diet-induced metabolic (insulin resistance), neurobehavioral (anxiety, depression and memory deficit), and neurochemical (oxidative, inflammatory and neurotrophic factor) alterations in the prefrontal cortex of obese rats’ brain. The involvement of CB2R and/or PPAR-γ dependent activity was also investigated.

Experimental approach: Male Wistar rats were fed a high fat/fructose diet (HFFD) for 12 weeks to induce IR and obesity. Rats were treated with BCP for the last 4 weeks. Either CB2R antagonist AM630 or PPAR-γ antagonist BADGE was administered before BCP treatment to study the mechanism of BCP actions.

Key results: Beta-caryophyllene alleviated HFFD-induced IR, oxidative-stress, neuroinflammation and behavioral changes. The anxiolytic, anti-oxidant and anti-inflammatory effects of BCP were mediated by both PPAR-γ and CB2R. The effects of BCP on glycemic parameters seem to be CB2R-dependent with the non-significant role of PPAR-γ. Furthermore, BCP-evoked antidepressant and memory improvement are likely mediated only via CB2R, mainly by upregulation of PGC-1α and BDNF.

Conclusion: This study suggests the potential effect of BCP in treating HFFD-induced metabolic and neurobehavioral alterations. BCP seems to activate PPAR-γ in a ligand-independent manner, via upregulation and activation of PGC-1α. The BCP activation of PPAR--γ seems to be CB2R-dependent.

Abstract

Acetochlor (ACT) is a chiral chloroacetamide pesticide that has been heavily used around the world, resulting in its residues being frequently found in surface waters. It has been reported that ACT is an endocrine disrupting chemical (EDC) with strong thyroid hormone-disrupting activity in aquatic organisms. However, the enantioselectivity underlying thyroid disruption has yet to be understood. In this study, using a zebrafish embryo-larvae model, the enantioselective thyroid disruption of ACT was investigated at a series of environmentally relevant concentrations (1, 2, 10 and 50?μg/L). Our results showed that both racemic ACT and its enantiomers significantly increased the malformation rates of embryos at 72?h postfertilization (hpf). Decreased thyroxine (T4) contents and increased triiodothyronine (T3) contents were found in larvae at 120?hpf, with (+)-S-ACT exhibiting a greater effect than (?)-R-enantiomer. Similarly, (+)-S-ACT also showed a stronger effect on the mRNA expressions of thyroid hormone receptors (TRα and TRβ), deiodinase2 (Dio2) and thyroid-stimulating hormone-β (TSHβ) genes. The observed enantioselectivity in TR expressions was consistent with that of in silico binding analysis, which suggested that (+)-S-enantiomer binds more potently to the TRs than (?)-R-enantiomer. In general, ACT enantiomers showed different influences on the secretion of THs, expression of TH-related key genes and binding affinity to TRs. Considering the different toxicity of different enantiomers, our study highlights the importance of enantioselectivity in understanding of thyroid disruption effects of chiral pesticides.

Abstract

The aim of this study was to investigate the protective effect of montelukast (MTK) against prednisolone-induced hepatic injury in rats. Twenty-eight male albino rats were categorized into four equal groups. Group I served as the control group; group II: rats orally received prednisolone (5?mg·kg^?1·d^?1) for 30 days; groups III and IV: rats orally received MTK at 10 and 20?mg·kg^?1·d^?1, respectively, simultaneously with prednisolone for 30 days. Serum liver enzymes, hepatic mitochondrial function, oxidative/nitrosative stress, and inflammatory and apoptotic markers were evaluated, and the results were confirmed by histopathological examination. MTK showed significant hepatic protection evidenced by alleviated histological lesion and improvement of mitochondrial function, oxidative/nitrosative stress, and inflammatory and apoptotic changes induced by prednisolone, with more profound protection in higher MTK dose (20?mg·kg^?1). In view of these findings, we can conclude that MTK may have hepatoprotective potential, beyond its therapeutic value for asthmatic patients during their course of corticosteroid therapy.

Abstract

Psoriasis is a chronic inflammatory systemic disease. Growing evidence suggests that human homeostasis depends on a mutualistic relationship with gut bacteria that produce a number of biologically active compounds. Therefore, enteric microbiota dysbiosis with gut barrier disruption may be an important factor in the development of chronic inflammatory diseases. The aim of our study was to assess non‐invasive markers of intestinal barrier integrity in patients with moderate to severe psoriasis. Concentrations of claudin‐3 (intestinal epithelial tight junction structure) and intestinal fatty acid binding protein (I‐FABP; marker of enterocyte damage) were determined in the blood of patients with chronic plaque psoriasis (n = 20) and healthy individuals (n = 20) using commercially available enzyme‐linked immunoassay test kits. Claudin‐3 concentration was higher in patients with psoriasis compared with healthy control (median, 54.07 vs 42.36 ng/mL; P < 0.001). Patients with psoriasis also had elevated concentration of plasma I‐FABP (median, 708.8 vs 147.1 pg/mL; P < 0.05). Our results support the hypothesis that dysfunction of the intestinal barrier in psoriasis disturbs the homeostatic equilibrium between the microbiota and immune system. Further studies are needed in order to develop new therapeutic interventions based on modulation of intestinal permeability.