FA-treated Rats Research Articles

Mitigating effect of ferulic acid on di-(2-ethylhexyl) phthalate-induced neurocognitive dysfunction in male rats with a comprehensive in silico survey

Di-(2-ethylhexyl) phthalate (DEHP) is the most abundant phthalate threatening public health-induced neurotoxicity. This neurotoxicity is associated with behavioral and biochemical deficits in male rats. Our study investigated the neuroprotective effect of ferulic acid (FA) on male rats exposed to DEHP. Thirty-two male Wistar rats were assigned to four groups. Group I control rats received corn oil, group II intoxicated rats received 300 mg/kg of DEHP, group III received 300 mg/kg of DEHP + 50 mg/kg of FA, and group IV received 50 mg/kg of FA, all agents administrated daily per os for 30 days. Anxiety-like behavior, spatial working memory, and recognition memory were assessed. Also, brain oxidative stress biomarkers, including brain malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), superoxide dismutase (SOD), brain-derived neurotrophic factor (BDNF) as well as heme oxygenase-1 (HO-1) were measured. Moreover, brain histopathology examinations associated with immunohistochemistry determination of brain caspase-3 were also evaluated. Furthermore, docking simulation was adapted to understand the inhibitory role of FA on caspase-3 and NO synthase. Compared to DEHP-intoxicated rats, FA-treated rats displayed improved cognitive memory associated with a reduced anxious state. Also, the redox state was maintained with increased BNDF levels. These changes were confirmed by restoring the normal architecture of brain tissue and a decrement in the immunohistochemistry caspase-3. In conclusion, FA has potent antioxidant and antiapoptotic properties that confirm the neuroprotective activity of FA, with a possible prospect for its therapeutic capabilities and nutritional supplement value.

Ganoderma Lucidum from Red Mushroom Attenuates Formaldehyde-Induced Liver Damage in Experimental Male Rat Model.

Simple SummaryFormaldehyde exposure is common due to inhalation and its presence in some food additives. Upon exposure to formaldehyde via any route, it is majorly metabolized by the liver. However, this metabolism impacts negatively on the liver, and in certain concentrations can result in liver damage referred to as hepatotoxicity. This toxicity is evident by a decrease in antioxidant markers as well as an increase in liver function enzymes, inflammatory markers as well as lipid profile in Wistar rats as shown by this study. To combat the deleterious effect of formaldehyde exposure, this study has shown that Ganoderma lucidum from red mushroom presents an excellent natural resource by ameliorating the aforementioned liver toxicity markers. This study should serve as a deterrent for those in the practice of using formaldehyde as food additives. Environment inspectors and governments should ensure that formaldehyde is kept below its toxicity threshold in work environments. However, in cases where hepatotoxicity has ensued or is suspected, Ganoderma lucidum could serve as a way to combat this toxicity but should be used under appropriate medical expert supervision.The majority of liver-related illnesses are caused by occupational and domestic exposure to toxic chemicals like formaldehyde (FA), which is widely common in Africa and the world at large. Hence, measures should be taken to protect humans from its hazardous effects. This study, therefore, examines the protective potential of Ganoderma lucidum (100 mg/kg body weight) on formaldehyde-induced (40%) liver oxido-inflammation in male rats. Male Wistar rats, 150–200 g, were allotted into four groups of 10 animals as follows: Group 1 was orally treated with 1 mg/mL distilled water, Group 2 was exposed to a 40% formaldehyde vapor environment for 30 min per day, Group 3 was orally treated with 100 mg/kg ethanol extract of Ganoderma lucidum, and Group 4 was co-administered formaldehyde and 100 mg/kg ethanol extract of Ganoderma lucidum. Rats were then sacrificed 24 h after administering the last dose of treatment, and the livers were excised. Ganoderma lucidum significantly reversed the formaldehyde-mediated reduction in body and organ weight. Ganoderma lucidum administration significantly prevented oxido-inflammation by reducing the levels of hydrogen peroxide and malondialdehyde and increasing the activity of antioxidant enzymes and glutathione contents, as well as the normal level of nitrite and myeloperoxidase production in FA-treated rats. Additionally, Ganoderma lucidum reversed a large decline in proinflammatory markers in formaldehyde. Furthermore, Ganoderma lucidum restores formaldehyde-induced histological alterations in the liver. Collectively, our results provide valuable information on the protective potential of Ganoderma lucidum in protecting formaldehyde-induced liver oxido-inflammation in male rats.

TOXIC EFFECTS OF FORMALDEHYDE ON CELLULAR IMMUNITY AND POSSIBLE RELATIONSHIP TO ITS RISK OF CARCINOGENESIS: AN EXPERIMENTAL STUDY

Exposure to formaldehyde (FA) can occurs either in the environment or in workplaces due to its common use in laboratory, industry, household and cosmotic products. This study was carried out to assess toxic effects of subacute exposure to FA on immune system in adult male albino rats and possible relationship to its risk of carcinogenesis. Methods: Fifty adult male albino rats were used for 28 days as follow: Group I: (20 rats) subdivided equally into group Ia negative control and group Ib positive control. Formaldehyde group: included 30 rats divided equally into groups II, III & IV received FA by oral gavage at doses of 20, 40 and 80 mg/kg respectively. Methods: At the end of the study, spleen of each rat was dissected and subjected to histopathological examination, immunohistochemical staining for CD4+ and comet assay. Blood samples were withdrawn and used for evaluation of T-lymphocytes subsets (CD3+, CD4+ and CD8+), CD19+ B-lymphocytes and CD56+ natural killer (NK) cells by flow cytometric analysis and cytokines profiles of interleukin 10 (IL-10) & interferon-gamma (IFN-γ) by enzyme-linked immunosorbent assay (ELISA) technique. Results: Histopathological and immunohistochemical studies showed decrease in the size of lymphocytes follicles with congestion of sinusoids and decreased expression for CD4+ in FA treated rats. Comet assay detected DNA damage in splenocytes of FA group. There was significant decrease in all T-lymphocytes subsets in groups III &IV with no significant difference was detected in group II. B- lymphocytes showed a significant increase in groups III & IV, however NK cells revealed a significant decrease only in group IV. Assessment of cytokines detected a significant increase in IL-10 in all FA-treated rats, while IFN-γ was decreased in groups III & IV. Conclusion: Formaldehyde exposure resulted in a dose-dependent immunotoxic effects and these effects may be related to its risk of carcinogenesis.

Dose-dependent neuroprotective effect of oriental phyto-derived glycyrrhizin on experimental neuroterminal norepinephrine depletion in a rat brain model

The dose-dependent neuroprotective role of licorice-derived glycyrrhizin during subacute neuroterminal norepinephrine (NE) depletion was studied in rat brain. Experimental design included thirty 5-week-old male rats randomly divided into five groups. Compared to the saline-injected control group, the group receiving daily intraperitoneal injection of fusaric acid (FA; 5 mg/kg/b.w.) for 30 days showed pharmacological depletion of NE. The neuroprotective effects of three successively increasing oral doses of glycyrrhizin were examined in FA-treated rats. Neurochemical parameters and histo-/immunohistopathological changes in the hippocampus were examined. FA generated global hippocampal stress with altered neurobiochemical parameters, accompanied by immune-confirmed inflammatory tissue damage, and noticeable behavioral changes. Although glycyrrhizin after FA-induced intoxication did not correct the recorded drop in the NE level, it decreased the dopamine levels to control levels. Similarly, glycyrrhizin at a high dose restored the serotonin level to its normal value and blocked the FA-induced increase in the level of its metabolite, 5-hydroxyindoleacetic acid. The FA-induced rise in γ-aminobutyric acid (GABA) and histamine was alleviated after administration of a high dose of glycyrrhizin. This was accompanied by improvements in the bioenergetic status and neuronal regenerative capacity through recovery of ATP and brain-derived neurotrophic factor levels to the pre-intoxicated values. High doses of glycyrrhizin also ameliorated the FA-generated behavioral changes and oxidative damage, manifested by the reduction in the expression of cortical pro-apoptotic caspase 3 in the same group. This study suggests that glycyrrhizin can potentially mend most of the previously evoked neuronal damage induced by FA intoxication in the brain of an experimental rat model.

Nigella sativa protects against formaldehyde-induced neurotoxicity in the rat frontal cortex

Objectives: Nigella sativa (NS) is well known for its strong antioxidant properties. The aim of this study was to investigate the potential protective effect of NS, as a potent antioxidant and free radical scavenger, on the rat frontal cortex following formaldehyde (FA)-induced neuronal injury and oxidative stress. Methods: Forty albino rats were divided into four groups (n=10, each): control group received 1 ml distilled water, NS treated group crushed seeds of NS at a single daily dose of 180 mg/kg/bw orally for two weeks, FA-treated group 10 mg/kg/bw FA i.p. daily for two weeks, and FA and NS treated group received 10 mg/kg/bw FA i.p. followed by a single dose of NS (180 mg/kg/bw) orally for 2 weeks. The animals then were sacrificed and the frontal lobes were excised. Frontal cortex was stained with hematoxylen-eosin and caspase-3 immunohistochemistry to identify cell morphology and apoptosis. Lipid peroxide, nitric oxide, superoxide dismutase and glutathione levels were measured. Results: Histological examination revealed severe neurodegenerative changes in frontal cortex neurons in the FA-treated group as observed with hematoxylen-eosin and caspase-3 immunohistochemistry. However, these changes were partly prevented in the FA and NS-treated group. Apoptotic cell index in the frontal cortex decreased significantly in FA and NS treated rats compared to FA-treated rats. In the FA-treated group, lipid peroxide levels increased, while nitric oxide and glutathione levels decreased significantly compared with controls. In the FA + NS treated group, nitric oxide, glutathione and superoxide dismutase levels increased and lipid peroxide level decreased significantly when compared with the FA-treated group. Conclusion: NS administration protects frontal cortex neurons against oxidative damage induced by FA. Keywords: cerebral cortex; formaldehyde; neuronal injury; Nigella sativa; oxidative stress; rat

Effluent Tenascin-C Levels Reflect Peritoneal Deterioration in Peritoneal Dialysis: MAJOR IN PD Study

Peritoneal deterioration causing structural changes and functional decline is a major complication of peritoneal dialysis (PD). The aim of this study was to explore effluent biomarkers reflecting peritoneal deterioration. In an animal study, rats were intraperitoneally administered with PD fluids adding 20 mM methylglyoxal (MGO) or 20 mM formaldehyde (FA) every day for 21 days. In the MGO-treated rats, tenascin-C (TN-C) levels in the peritoneal effluents were remarkably high and a cluster of TN-C-positive mesothelial cells with epithelial-to-mesenchymal transition- (EMT-) like change excessively proliferated at the peritoneal surface, but not in the FA-treated rats. Effluent matrix metalloproteinase-2 (MMP-2) levels increased in both the MGO- and FA-treated rats. In a clinical study at 18 centers between 2006 and 2013, effluent TN-C and MMP-2 levels were quantified in 182 PD patients with end-stage renal disease. Peritoneal function was estimated using the peritoneal equilibration test (PET). From the PET results, the D/P Cr ratio was correlated with effluent levels of TN-C (ρ = 0.57, p < 0.001) and MMP-2 (ρ = 0.73, p < 0.001). We suggest that TN-C in the effluents may be a diagnostic marker for peritoneal deterioration with EMT-like change in mesothelial cells in PD.

Formaldehyde–protein Conjugate-specific Antibodies in Rats Exposed to Formaldehyde

A large human population is exposed to formaldehyde (FA) environmentally and occupationally, leading to a variety of respiratory and dermatological disturbances. FA covalently binds with proteins to form FA–protein conjugates, which might lead to the formation of FA-specific antibodies. The focus of this investigation was to study the formation of antibodies against FA–protein conjugates in rats for their possible use as biological markers of FA exposure. Male Sprague-Dawley rats were fed FA via drinking water (1.6 mg/ml) for up to 6 mo. Blood was collected at 3 and 6 mo following FA exposure, and formation of anti-FA–albumin adduct (anti-FAA) antibodies measured in the serum samples (1:100 dilution) by an enzyme-linked immunosorbent assay (ELISA) using synthesized rat albumin conjugates of FA as the solid-phase antigen. Sera from FA-treated rats showed induction of antibodies to FAA in 50% of the animals at both 3 and 6 mo, and the antibody titer was higher at 6 mo, suggesting a greater antibody response with exposure period. These antibodies were highly specific for FAA as they did not cross-react with malondialdehyde–, 4-hydroxynonenal–, 4-hydroxyhexenal–, and acrolein–albumin adducts. The specificity of anti-FAA antibodies was further evaluated by inhibition studies that showed a dose-dependent decrease in binding when the serum was preincubated with increasing concentrations of FAA, and by Western blot analysis that showed immunoreactivity of the antibody with FAA but not with rat albumin. Furthermore, the anti-FAA antibodies (rat serum) also recognized FA–human albumin (FAHA) conjugates, but had only approximately one-third of the binding affinity in comparison to FAA. Induction of anti-FA–protein conjugate antibodies could be further evaluated to serve as a biomarker of FA exposure.

Inhibitors of cyclic nucleotide phosphodiesterase isozymes block renal tubular cell proliferation induced by folic acid

In previous studies we observed that inhibition of cyclic 3′,5′-nucleotide phosphodiesterase (PDE) isozymes, namely isozyme PDE3, suppresses proliferation of rat renal glomerular mesangial cells in vitro and in vivo. To determine whether activation of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway coupled to specific PDE isozymes modulates accelerated proliferation of renal epithelial cells, we investigated the effect of selective PDE isozyme inhibition on renal epithelial cell proliferation induced in rats by injection of folic acid (FA). In extracts from suspensions of renal cortical tubules, cAMP was metabolized predominantly by isozyme PDE4; activity of PDE3 was about three times lower. The increase in proliferative activity of renal cortical tissue from FA-injected rats, evaluated by immunostaining with Mib-1 antibody, was limited to tubular epithelial cells. Administration of the PDE3 inhibitors cilostazol or cilostamide together with the PDE4 inhibitor rolipram blocked mitogenic synthesis of DNA, as determined by ( 3H)-thymidine incorporation into renal cortical DNA, in FA-treated rats. FA injection caused an increase of more than 10-fold in proliferating cell nuclear antigen (PCNA) in renal cortical tissue; administration of the potent PDE3 inhibitor lixazinone or, to a lesser degree, cilostazol suppressed these high PCNA levels, whereas rolipram alone had no effect. The results indicate that FA-stimulated in vivo proliferation of renal tubular epithelial cells is down-regulated by activation of a cAMPPKA signaling pathway linked to PDE3 isozymes. These observations are consistent with the notion that negative crosstalk between cAMP signaling and mitogenstimulated signaling pathways regulates mitogenesis of renal cells of different terminal differentiation, including tubular epithelial cells.

Regulation of IL-6 and the hepatic IL-6 receptor in acute inflammation in vivo

The serum levels of interleukin 6 (IL-6) and the expression (mRNA) of the 80 kDA IL-6 receptor (IL-6R) were examined in three different models of acute inflammation. Rats were treated with either Freund's complete adjuvant (FA) via intraperitoneal injection, LPS via intravenous injection, or turpentine via subcutaneous injection. Using bio- and specific immunoassays, rat serum levels of IL-6, corticosterone, and acute phase proteins were quantified. LPS treatment induced the quickest and greatest serum IL-6 response (>100 ng/ml within 3 h). In comparison, sera from turpentine and FA-treated rats contained much lower levels of IL-6 activity (<10 ng/ml). Serum corticosterone levels increased by 3 h after injection in all three models, and equivalent raised serum levels of acute phase proteins were detected within 12–24 h. The expression of IL-6 receptor mRNA in hepatocytes increased markedly as early as 3 h after treatment and message levels began to decline by 6–12 h in all three models. To analyze the individual effects of raised corticosterone and IL-6 on the expression of hepatic IL-6R mRNA, rats were injected with either dexamethasone (Dex) or purified recombinant rat IL-6 (rIL-6) via intraperitoneal injection. Rats injected with rIL-6 showed highly induced IL-6R mRNA levels as early as 1 h after injection, and Dex-injected rats showed a significant but less dramatic rise in IL-6R message levels. Dex- or rIL-6-injected rats demonstrated a distinct profile of acute phase protein response different from that seen in the three experimental models. Regulation of IL-6R gene expression in the liver in vivo depends on a complex interaction between the hepatocyte and a combination of cytokines and other hormones.

Prolonged inflammatory pain modifies corticotropin-releasing factor-induced opioid peptide release in the hypothalamus

The influence of prolonged pain upon hypothalamic opioid peptide release in vitro was examined in rats subjected to Freund's adjuvant (FA)-induced unilateral inflammation of the hindlimb. Basal release of enkephalin (ENK) but not ß-endorphin (END) or dynorphin (DYN) was increased 10 days following FA treatment. Superfusion of corticotropin-releasing factor (CRF; 10 −8 M) stimulated the release of opioid peptides in control hypothalami. CRF, however, failed to modify ß-END and DYN release in hypothalami of FA-treated rats, whereas ENK release was markedly reduced. In contrast, KCl-stimulated opioid peptide release did not differ between FA and control hypothalami. These data demonstrate that prolonged inflammatory pain alters the responsiveness of hypothalamic opioid systems to CRF. It is suggested that this effect is mediated at the level of the CRF neuron or its receptor.

Motivational effects of opioids in an animal model of prolonged inflammatory pain: alteration in the effects of κ-but not of μ-receptor agonists

An unbiased preference conditioning procedure was used to characterize and compare the motivational effects of opioids in naive rats and those suffering from the prolonged pain associated with Freund's adjuvant (FA)-induced inflammation of one hind limb. The μ-opioid agonist morphine functioned as a reinforcer in naive animals, producing marked preferences for the drug-paired place. Similarly, rats injected with FA 7 days prior to conditioning exhibited a preference for the morphine place and the magnitude of this effect did not differ between groups. Administration of the κ-opioid receptor agonist U-69593 to naive rats produced dose-related place aversions. The aversive effect of this κ-agonist was, however, abolished in FA-treated rats. Thus, regardless of the dose administered, U-69593 produced conditioning similar to that observed in response to saline. These data suggest that κ-agonists may lack aversive effects in subjects experiencing prolonged noxious stimulation and as such may be effective therapeutic agents in the management of chronic pain states.