Expression of cardiac inwardly rectifying potassium channels in pentylenetetrazole kindling model of epilepsy in rats

Clinical and experimental studies show that epilepsy affects cardiac function; however, the underlying molecular mechanism has not been fully elucidated. Inwardly-rectifying potassium (Kir) channels transport K+ ions into excitable cells such as neurons and cardiomyocytes; they control the cell excitability by acting towards the repolarization phase of cardiac action potential. Kir channel expression has been previously shown to vary in epileptic brains, at the same time seizures are known to affect the autonomic nervous system. Kir channel expression in cardiac tissue is a possible mechanism for the explanation of cardiac pathology in epilepsy. We investigate the expression of Kir channels in epileptic cardiac tissue by using pentylenetetrazole (PTZ)-kindling model in rats. Our molecular analyses showed significant decrease in cardiac Kir channel mRNA and protein expression of PTZ-kindled rats. Interestingly, both Kir2.x, which directs IK1 flux in ventricular tissue and Kir3.x, which is responsible for IKACh in the atria, were observed to decrease significantly. Kir channel expression also differs between females and males. This is the first study to our knowledge in epileptic cardiac tissue showing the expression of Kir channels. Our results show that Kir channels may play a role in cardiac pathology associated with epilepsy.

Counteraction of perforated cecum lesions in rats: Effects of pentadecapeptide BPC 157, L-NAME and L-arginine

AIM

To study the counteraction of perforated cecum lesion using BPC 157 and nitric oxide (NO) system agents.

METHODS

Alongside with the agents’ application (after 1 min, medication (/kg, 10 mL/2 min bath/rat) includes: BPC 157 (10 μg), L-NAME (5 mg), L-arginine (100mg) alone or combined, and saline baths (controls)) on the rat perforate cecum injury, we continuously assessed the gross reappearance of the vessels (USB microcamera) quickly propagating toward the defect at the cecum surface, defect contraction, bleeding attenuation, MDA- and NO-levels in cecum tissue at 15 min, and severity of cecum lesions and adhesions at 1 and 7 d.

RESULTS

Post-injury, during/after a saline bath, the number of vessels was significantly reduced, the defect was slightly narrowed, bleeding was significant and MDA-levels increased and NO-levels decreased. BPC 157 bath: the vessel presentation was markedly increased, the defect was noticeably narrowed, the bleeding time was shortened and MDA- and NO-levels remained normal. L-NAME: reduced vessel presentation but not more than the control, did not change defect and shortened bleeding. L-arginine: exhibited less vessel reduction, did not change the defect and prolonged bleeding. In combination, mutual counteraction occurred (L-NAME + L-arginine) or the presentation was similar to that of BPC 157 rats (BPC 157 + L-NAME; BPC 157 + L-arginine; BPC 157 + L-NAME + L-arginine), except the defect did not change. Thereby at day 1 and 7, saline, L-NAME, L-arginine and L-NAME + L-arginine failed (defect was still open and large adhesions present).

CONCLUSION

The therapeutic effect was achieved with BPC 157 alone or in combination with L-NAME and L-arginine as it was able to consolidate the stimulating and inhibiting effects of the NO-system towards more effective healing recruiting vessels.

Hepatotoxicity induced by psoralen and isopsoralen from Fructus Psoraleae: Wistar rats are more vulnerable than ICR mice

Fructus Psoraleae (FP) causes cholestatic liver injury; however, its main toxic constituents that are responsible for causing hepatotoxicity remained undetermined in previous studies. In the present study, psoralen and isopsoralen, the two main constituents of FP, were administered orally to rats (80 and 40 mg/kg, respectively) and mice (320 and 160 mg/kg, respectively) for 28 days, followed by biochemical and histopathological examinations to evaluate their hepatotoxicity. The results showed that psoralen and isopsoralen could induce the toxic reactions of liver and other organs in rats, while mice were not sensitive to these two compounds. Furthermore, the corresponding results indicated that administration of psoralen and isopsoralen repressed the expression of CYP7A1, BSEP, MRP2 and SULT2A1 and increased the expression of FXR and MRP3 in the rat liver. In summary, the toxic reactions of psoralen and isopsoralen are different in different species. In this study, multiple organ toxicity, such as cholestatic liver injury, occurs in rats, but not in mice. Psoralen and isopsoralen are the two main toxic constituents of FP. In addition, psoralen and isopsoralen cause liver injury, possibly through inhibiting bile acid excretion in the liver, leading to the accumulation of toxin in hepatocytes.

Bypassing major venous occlusion and duodenal lesions in rats, and therapy with the stable gastric pentadecapeptide BPC 157, L-NAME and L-arginine

AIM

To investigate whether duodenal lesions induced by major venous occlusions can be attenuated by BPC 157 regardless nitric oxide (NO) system involvement.

METHODS

Male Wistar rats underwent superior anterior pancreaticoduodenal vein (SAPDV)-ligation and were treated with a bath at the ligated SAPDV site (BPC 157 10 μg, 10 ng/kg per 1 mL bath/rat; L-NAME 5 mg/kg per 1 mL bath/rat; L-arginine 100 mg/kg per 1 mL bath/rat, alone and/or together; or BPC 157 10 μg/kg instilled into the rat stomach, at 1 min ligation-time). We recorded the vessel presentation (filled/appearance or emptied/disappearance) between the 5 arcade vessels arising from the SAPDV on the ventral duodenum side, the inferior anterior pancreaticoduodenal vein (IAPDV) and superior mesenteric vein (SMV) as bypassing vascular pathway to document the duodenal lesions presentation; increased NO- and oxidative stress [malondialdehyde (MDA)]-levels in duodenum.

RESULTS

Unlike the severe course in the SAPDV-ligated controls, after BPC 157 application, the rats exhibited strong attenuation of the mucosal lesions and serosal congestion, improved vessel presentation, increased interconnections, increased branching by more than 60% from the initial value, the IAPDV and SMV were not congested. Interestingly, after 5 min and 30 min of L-NAME and L-arginine treatment alone, decreased mucosal and serosal duodenal lesions were observed; their effect was worsened at 24 h, and no effect on the collateral vessels and branching was seen. Together, L-NAME+L-arginine antagonized each other’s response, and thus, there was an NO-related effect. With BPC 157, all SAPDV-ligated rats receiving L-NAME and/or L-arginine appeared similar to the rats treated with BPC 157 alone. Also, BPC 157 in SAPDV-ligated rats normalized levels of NO and MDA, two oxidative stress markers, in duodenal tissues.

CONCLUSION

BPC 157, rapidly bypassing occlusion, rescued the original duodenal flow through IAPDV to SMV flow, an effect related to the NO system and reduction of free radical formation.

Role of bitter leaf (Vernonia amygdalina) extract in prevention of renal toxicity induced by crude petroleum contaminated diets in rats

The efficacy of Vernonia amygdalina against chemical toxicity has attracted attention. The aim of this study was to evaluate the protective potentials of Vernonia amygdalina methanol extract (BLME) against petroleum toxicity. Thirty six male albino rats (Rattus norvegicus) were redistributed randomly into six groups of six rats each and fed with growers feed for a period of 30 days according to the following description: Group A = Feed; Group B = Feed + 100 mg kg⁻¹ body weight of BLME; Group C = Feed + 200 mg kg⁻¹ body weight of BLME; Group D = Feed (100 g Feed + 4 mL crude petroleum); Group E = Feed (100 g Feed + 4 mL crude petroleum) + 100 mg kg⁻¹ body weight of BLME; Group F = Feed (100 g Feed + 4 mL crude petroleum) + 200 mg kg⁻¹ body weight of BLME. Animals were sacrificed at the end of the experimental period and the serum and kidney were harvested for biochemical and histological analysis following standard procedures. The data generated were subjected to analysis of variance (ANOVA). The study revealed that crude petroleum stimulated alterations in kidney dysfunction makers: urea, creatinine and serum electrolytes which were significantly (P < 0.05) ameliorated by BLME administration relative to control. Oxidative stress markers, lipid peroxidation and enzymatic and non-enzymatic antioxidant profiles (MDA levels, GSH, Vitamin C. FRAP, CAT, SOD, GPx, GSTs) as well as oxidase enzymes (AO, SO, MO and XO) induced changes by crude petroleum were positively modulated by BLME administration. The study concluded that crude petroleum contaminated diets are injurious to animal health and BLME is able to prevent the renal dysfunction induced by crude petroleum contaminated diets.

Nutritional value of detoxified Jatropha curcas seed cake protein isolates using rats as an animal model

A bioassay study was conducted to investigate the effects of substituting casein with graded levels of detoxified Jatropha curcas seed cake protein isolates (JPI) as a protein source on the growth performance, feed efficiency ratio (FER) and its protein values using rats as an animal model. Thirty 21-day-old male Sprague-Dawley weaned rats were randomly divided into 5 groups, each group with 6 replications (n = 1). Each group consumed one of the following diets: protein-free, casein (CAS) and JPI diets (JPI_20, JPI₄₀ and JPI₆₀; different levels of JPI to replace the casein at concentrations of 20%, 40% and 60% on crude protein basis). Feed intake and protein intake showed no difference among the rats fed JPI₂₀, JPI₄₀ and CAS diets (P > 0.05). However, these parameters were lower in the rats fed JPI₆₀ than in rats fed CAS (P < 0.05). The rats fed diets containing JPI had lower body weight gain, protein efficiency ratio and net protein retention than those fed CAS diet (P < 0.05). When the level of JPI used to replace the casein was lower than 40%, protein efficiency ratio (PER) was close to or higher than 2.0, which suggests that JPI could be viewed as a high-quality protein. Inclusion of JPI in the diet decreased alkaline phosphatase activity. The values were significantly lower in rats fed JPI₂₀ and JPI₄₀ than in rats fed CAS (P < 0.05). No histopathological changes were observed in livers and kidneys in the rats fed JPI diets. The results demonstrate that JPI could be used as an efficient protein source at a level of no more than 40% of dietary protein source.

Comb-like PEG-containing polymeric composition as low toxic drug nanocarrier

BACKGROUND

Development of biocompatible multifunctional polymeric drug carriers is crucial in modern pharmaceutics aimed to create "smart" drugs. The high potential of the PEGylated comb-like polymeric nanocarrier (PNC) in delivering both traditional and experimental drugs to tumor cells in vitro and in vivo has been demonstrated previously. In the present study, we investigated the general toxicity of polyethylene glycol (PEG) processed with both covalent and non-covalent attachments of PEG to compose a comb-like polymer that behaves like a simple chain of n monomers decorated with swollen side chains. The PNC possesses properties of a water-soluble surfactant containing methyl-terminated PEG side branches in some monomer units attached covalently to the carbon chain backbone.

RESULTS

We have demonstrated that the synthesized PNC possesses weak toxic effects toward human leukemia cells (HL-60 and Jurkat lines), as well as toward hepatocellular (HepG2), colon (HCT116) and breast (MCF-7) tumor cell lines. Additionally, after a long period (20 days) of intraperitoneal administration, the PNC had no significant toxic effects in laboratory white mice (470 mg/kg body mass in 1 ml) and Wistar rats (440 mg/kg body mass in 10 ml).

CONCLUSION

The developed PNC we studied can be qualified as a compound of grade 4 toxicity (low toxicity substance). The reduced toxicity of this PNC in combination with its improved bioavailability and previously detected capability to enhance cytotoxicity toward tumor cells in vitro and potential tumor treatment effects in vivo suggests its potential as a safe drug delivery platform for treating various diseases, especially cancer.

Synergistic effect of vancomycin and l-homocarnosine alleviates Staphylococcus aureus-induced osteomyelitis in rats

Osteomyelitis is a well-known bone infection in humans. The primary symptoms are fever, pain, weakness, and redness of the bone. l-Homocarnosine is a bioactive peptide abundant in brain and skeletal muscles. The present study evaluated the synergistic effect of vancomycin and l-homocarnosine against osteomyelitis in the Staphylococcus aureus-induced rat model of osteomyelitis. Animals were classified into the following groups: sham (group I), osteomyelitis (group II, control), vancomycin (25 mg/kg body weight, group III), l-homobrassinolide (25 mg/kg body weight, group IV), and vancomycin (25 mg/kg body weight) + l-homobrassinolide (25 mg/kg body weight) (group V). Lipid peroxidation, superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase, reduced glutathione (GSH), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were determined. Assessments of bacterial growth and histopathological analyses were carried out. Lipid peroxidation, GSH, SOD, catalase, and Gpx levels recovered to near normal levels with the combined treatment of vancomycin and l-homocarnosine. TNF-α and IL-6 levels were reduced to near normal levels. Combined supplementation of vancomycin and l-homocarnosine reduced bacterial growth in bone and wire. Furthermore, bone infections and histopathological scores were also reduced. In summary, we showed that combined treatment of vancomycin and l-homocarnosine was more effective against bacterial growth and bone infection compared to monotherapy with vancomycin or l-homocarnosine.

Effects of intracerebroventricular injection of vitamin B12 on formalin-induced muscle pain in rats: Role of cyclooxygenase pathway and opioid receptors

Vitamin B₁₂ modulates pain at the local and peripheral levels. This study has investigated the effects of intracerebroventricular (ICV) injection of vitamin B₁₂ on themuscle pain. We used diclofenac (cyclooxygenase inhibitor) and naloxone (opioid receptors antagonist) to clarify the possible mechanisms. For ICV injections, a guide cannula was implanted in the left lateral ventricle of the brain. Muscle pain was induced by intramuscular injection of formalin (2.50%; 50 µl) in the right gastrocnemius muscle and the number of paw flinching was recorded at 5-min blocks for 60 min. Locomotor activity was performed using an open-field test. Formalin induced a biphasic pain. Vitamin B₁₂ (1.25, 2.50, 5.00 and 10.00 µg per rat) and diclofenac (12.50 and 25.00 µg per rat) significantly reduced both phases pain intensity. Significant antinociceptive effects were observed after combined treatments of diclofenac (6.25 and 12.50 µg per rat) with vitamin B₁₂ (0.63 and 2.50 µg per rat), respectively. Prior ICV injection of naloxone (10.00 µg per rat) prevented vitamin B₁₂ (10.00 µg per rat) and diclofenac (25.00 µg per rat) induced antinociceptive effects. All the above-mentioned chemicals did not alter locomotor behavior in an open-field test. The present results showed that the cyclooxygenase pathway and opioid receptors may be involved in the central antinociceptive effect of vitamin B₁₂. In addition, opioid receptors might be involved in diclofenac-induced antinociception.

Immediate and Late Effects of Stress on Kidneys of Prepubertal and Adult Rats

BACKGROUND/AIMS

Stress had been related to physiological and morphological alterations in different organs, however kidney morphology and function after stress conditions are not well-known. To evaluate the effects of chronic stress on renal morphology in prepubertal and adult rats, and to investigate if the effects of induced stress remain stable or worsen following removal of the stress stimuli.

METHODS

Forty prepubertal rats (4 weeks old) and thirty six adult rats (10 weeks old) were used. Each age group was divided a into control group and a stressed group. Stressed animals were restrained in rigid tubes 2 hours per day for 6 weeks. Animals were euthanized 24 hours after the last stress stimulus for immediate evaluation (50% of the groups), and 6 weeks after the last stress stimulus for late evaluation (50% of the groups). Kidney weight and volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted glomerular volume, and number of glomeruli per kidney were evaluated using the Image J software.

RESULTS

Prepubertal stressed animals showed reduced kidney weight and volume, and increased cortical-medullar ratio in comparison to its control group when evaluated immediately. Furthermore, stressed prepubertal and adult animals evaluated immediately had reduced glomerular volumetric density. Most importantly, all stressed groups exhibited reduced number of glomeruli per kidney. Other analyzed parameters did not difeer significantly the groups.

CONCLUSION

Chronic stress induced before and after puberty led to irreversible glomerular loss, however, renal impairment was interrupted by removal of the stress stimuli.

Dataset on significant role of Candesartan on cognitive functions in rats having memory impairment induced by electromagnetic waves

Rapid growing of mobile phones users has raised about the possible effects of these electromagnetic waves (EMW) on human health. Many studies have examined the role of these EMW on biological systems, but the results are still contradictory and controversial. In addition to EMW, over-activation of angiotensin type 1 receptor (AT1R) has been associated with cognitive decline, incidence and progression of neurodegenerative diseases. Candesartan, an AT1R blocker, is well recognized for treatment of hypertension. However, its role on cognitive functions such as spatial and recognition memory remains elusive. Thus, young rats were divided into 3 groups: control, exposed to radiofrequency electromagnetic waves (EMW), and exposed to EMW during Candesartan treatment (EMW+Cand). Spatial memory performance was assessed using the object recognition test and recognition memory performance using Morris water maze test. Significant differences where found between EMW exposed rats and EMW+Cand exposed rats treated with Candesartan compared to control, EMW group impaired learning, spatial and short term memory along with unaffected sensorimotor function whereas EMW+Cand group improved learning, spatial memory and short term memory deficit induced by EMW in addition to absence of its role on sensorimotor function. Although our data provides evidences of the protective role of Candesartan against EMW-induced cognitive decline, more future studies are still needed to confirm these findings which can provide new fields in treatment of EMW-induced damage by Candesartan.

Influence of Orexinergic System on Survival in Septic Rats

BACKGROUND

The orexinergic (OXergic) system contributes to the defense system. It has also been reported that the degeneration of OXergic neurons occurs during sepsis. Thus, the decline of OXergic activity may contribute to impairment of the defense system in sepsis. In this study, we determined whether: (i) lipopolysaccharide (LPS) reduces the brain orexin A (OXA) content and (ii) the OXergic system contributes to survival from sepsis in rats.

METHODS

With approval of our protocol by our University Animal Ethics Committee, OX neuron-ablated (OX/ataxin-3 transgenic [OX/AT3 TG]) and wild-type Sprague-Dawley rats, weighing 250-350 g, were used. LPS (10 mg/kg) was administered intraperitonally to the wild-type rats (group SD, n = 26) and OX/AT3 TG rats (group TG, n = 14). Another 7 SD rats were included as a saline control (group C). Survival analysis was then performed over a period of 3 days. All surviving rats were decapitated and the brain OXA contents (from the cerebrocortex, hippocampus, hypothalamus, and pons) were quantified using ELISA kits.

RESULTS

In group SD, 61.5% rats survived, while in group TG, only 21.4% survived (p < 0.05). LPS significantly reduced OXA content (pg/mg of tissue) in group SD (2.92 ± 0.38) compared to in group C (4.10 ± 1.21) in the pons (p < 0.05). OXA content in group TG was substantially lower than in group C and group SD in all brain regions.

CONCLUSIONS

LPS significantly reduced OXA contents in the pons which contains the locus coeruleus to regulate sympathetic activity in the defense system.

The Effect of MPP+ on the Viability of Primary Cortical Astrocytes Isolated from Female and Male Wistar Rats of Different Ages

Although age is known to be the main risk for developing chronic and neurodegenerative diseases, those illnesses have a different prevalence depending on the sex. It has been questioned whether genetic and hormonal differences are preserved in primary cultures from individuals of different genders. Therefore, here we studied the susceptibility of astrocytes, obtained from female and male Wistar rats of different ages (newborn, 9 and 24 months-old), to the well-known toxin MPP+ after 2 weeks in vitro, at different concentrations and exposure times. Our results showed that there are no variances due to gender, but that there are important differences associated to age in terms of the viability against this toxin.

Combined Effects of Electroacupuncture and Behavioral Training on Learning-Memory Ability and Event-Related Potential P300 in Rats with Mid/Advanced Cerebral Infarction

Background:

The effectiveness of the combination of electroacupuncture (EA) and behavioral training (BT) for mid/advanced cerebral infarction (M/ACI) and related mechanisms remains unclear. This study aimed to investigate the combined effects on the learning-memory ability and event-related potential P300 in rats with M/ACI.

Methods:

Eighty rats with M/ACI were divided into Group Model (M), Group EA, Group BT, and Group EA-BT (n = 20) according to the random number with five healthy rats in Group Control (CON). On the 6^th week after modeling, EA, BT, and EA-BT were given to Group EA, Group BT, and Group EA-BT, respectively, whereas Group M and Group CON were not given any intervention. Y-maze test and P300 were recorded before and after the intervention.

Results:

After intervention, the P300 latency was lower and the amplitude was higher in the Group EA-BT, Group EA, and Group BT than before (for latency, t = −7.638, −4.334, and −5.916; for amplitude, t = 8.125, 3.846, and 5.238; P < 0.01), with Group EA-BT superior to Group EA (for latency, t = −3.708; for amplitude, t = 3.653; P < 0.01) and Group BT (for latency, t = −2.067; for amplitude, t = 2.816; P < 0.05), with no significant difference between Group BT and EA (for latency, t = −1.439; for amplitude, t = 1.075; P > 0.05). While the performances of Y-maze tests in the Group EA-BT, Group EA, and Group BT were all better than before (t = 10.359, 4.520, and 7.791, P < 0.01), with Group EA-BT better than Group EA (t = 5.627, P < 0.01) and Group BT (t = 2.913, P < 0.01) respectively, and Group BT better than Group EA (t = 2.912, P < 0.01).

Conclusion:

EA or BT can affect P300 in rats with M/ACI, and the combination of these two methods can significantly improve the learning-memory ability.

UV-light mediated green synthesis of silver and gold nanoparticles using Cornelian cherry fruit extract and their comparative effects in experimental inflammation

The purpose of our study is to investigate the comparative effects of materials based on silver and gold nanoparticles functionalized with polyphenols from Cornus Mas extract (AgNPs-CM and AuNPs-CM) in vivo on experimental inflammation. The nanoparticles were obtained at room temperature under UV irradiation and were characterized by different methods: ultraviolet-visible spectroscopy, transmission electron microscopy, X ray diffraction, Fourier transform infrared spectroscopy and dynamic light scattering. The modulatory effects of AgNPs-CM and AuNPs-CM on inflammation were quantified by oxidative stress parameters, pro and anti-inflammatory cytokines levels and apoptosis assessment at 2 h, 24 and 48 h after induction of inflammation with carrageenan in the paw tissue of Wistar rats. Our results showed that silver and gold nanoparticles only partial and for a short period have mobilized the antioxidant defense mechanisms. In addition, they diminished inflammation and apoptosis in the early stage while later, at 48 h, exerted an immunomodulatory effect, activated ERK ½ and induced apoptosis. The photoreduced silver and gold nanoparticles, functionalized with natural compounds, modulated the inflammation in a similar manner in the soft tissue injected with carrageenan. In order to decipher the mechanisms involved in interactions of metallic nanoparticles with biological systems and for a complete assessment of the risks and benefits of these products in clinical practice long term studies are necessary.

Effects of acute olanzapine exposure on central insulin-mediated regulation of whole body fuel selection and feeding

The use of antipsychotics is associated with severe disruptions in whole body glucose and lipid metabolism which may in part occur through the central nervous system and impaired insulin action at the brain. Here we investigated whether olanzapine treatment might also affect the ability of central insulin treatment to regulate food intake and fuel preference in the light and dark cycle. Male Sprague-Dawley rats were treated with olanzapine (or vehicle solution; 3 mg/kg, subcutaneous) and a simultaneous acute intracerebral ventricular (ICV) infusion of insulin (or vehicle; 3 μL at 10mU; ICV) at the beginning of the 12-h light and dark cycles. Olanzapine treatment reduced RER in the dark and light phases (most consistently in the 4-hours post-treatment), while ICV insulin reduced average RER predominantly in the dark phase, but also at the end of the light cycle. The RER lowering effect of ICV-insulin during the light cycle was absent in the group co-administered olanzapine. The reduction in RER during the dark phase was mirrored by decreased food intake with ICV insulin, but not olanzapine treated rats. The reduction in food intake by ICV-insulin was abolished in rats co-administered olanzapine suggesting rapid induction of central insulin resistance. A combination of ICV-insulin and olanzapine similarly reduced RER in the dark phase, independent of changes in food intake. Olanzapine treatment, alone or in combination with ICV-insulin, significantly reduced VCO₂ at regular intervals in the dark phase (specifically 3 h post-treatment), while VO₂ was not significantly altered by either treatment. Finally, heat production was increased by olanzapine treatment in the light phase, though this effect was not consistent. The findings confirm that acute olanzapine treatment directly reduces RER and suggest that treatment with this drug may also override central insulin-mediated reductions in food intake at the hypothalamus (while still independently favoring fatty acid oxidation). Acute central insulin similarly reduces RER, but in contrast to olanzapine, this may represent a physiologically appropriate response to reduction in food intake.

Reversing the adverse biochemical effects in lead-intoxicated rats by N,N`- bis[(1,2-didehydro-1-hydroxy-2-thioxopyrid-4-yl)-carbonyl]- L-lysine

N,N`-Bis[(1,2-didehydro-1-hydroxy-2-thioxopyrid-4-yl)-carbonyl]- L-lysine (HTPL) is a novel newly synthesized compound intended to be used for the chelation of lead in intoxicated animals. Subchronic lead intoxication experiments were carried out on Wistar male rats; these rats were intoxicated with lead and then treated with HTPL. Results were compared with those obtained with known compounds used for lead chelation therapy, such as disodium ethylnediaminetetraacetic acid (CaNa₂EDTA) and meso-2,3-dimercaptosuccininc acid (DMSA), using different routes of administration. Biological samples of whole blood and urine were collected and analyzed for urinary proporphyrins, δ-aminolevulinic acid dehydratase, and zinc protoporphyrin. Results revealed that HTPL can remarkably reverse the toxic effects of lead intoxication at biochemical levels. Additionally, results showed that this agent is as good or even more potent than calcium disodium ethylnediaminetetraacetic acid (CaNa₂EDTA) and meso-2,3-dimercaptosuccininc acid (DMSA) in reversing the toxic effect of lead. More importantly, HTPL was found effective when administrated intraperitoneally and orally.

The potential protective influence of flaxseed oil against renal toxicity induced by thioacetamide in rats

The present study was aimed to evaluate the influence of flaxseed oil on renal toxicity induced by thioacetamide in male rats. The animals were distributed into four groups. Rats of the first group were served as control. Rats of the second group were exposed to thioacetamide. Rats of the third group were treated with flaxseed oil and thioacetamide. Rats of the fourth group were treated with flaxseed oil. Significant increases of blood creatinine and uric acid were observed in TAA-treated rats after three weeks. In thioacetamide group, the levels of serum creatinine, blood urea nitrogen and uric acid were significantly elevated after six weeks. Histopathologically, the renal sections from thioacetamide-treated rats showed severe alterations in the structure of renal corpuscles including a degeneration of glomeruli and Bowman's capsules. Administration of flaxseed oil protects the observed biochemical and histopathological alterations induced by thioacetamide exposure. Hence, the results of this study suggest that flaxseed oil protects against thioacetamide-induced renal injury and the protective influence of flaxseed oil may be attributed to its antioxidant role.

Nickel-induced neurodegeneration in the hippocampus, striatum and cortex; an ultrastructural insight, and the role of caspase-3 and α-synuclein

Human overexposure to nickel (Ni) emanating from the increasing application of Ni compounds in modern technology is a major public health concern. Nickel has been shown to be teratogenic, immunotoxic, genotoxic and carcinogenic. The current knowledge on Ni neurotoxicity is still relatively limited. We have previously demonstrated that Ni treatment alters cognitive and locomotor behaviors, induces oxidative stress and neurodegeneration in brains of rats. In this study, we examine the ultrastructural changes to neurons in the hippocampus, striatum and cortex of the brain following Ni treatment, as well as attempt to delineate the roles for caspase-3 and α-synuclein in Ni-induced neurodegeneration. Rats were treated with either saline, 10 or 20 mg/kg of nickel chloride for 4 weeks via oral gavage. Electron microscopy analysis revealed ultrastructural alterations in neurons of the hippocampus, striatum and cortex following Ni treatment. Mitochondria structural integrity within neurons were markedly compromised. We also detected elevated caspase-3 activity in hippocampus and striatum, as well as overexpression of α-synuclein in the cortex following Ni treatment. Our study demonstrates that mitochondria are a key target in Ni-induced neurodegeneration. Additionally, we implicate apoptotic pathway via caspase-3 action as the executioner and perturbation of α-synuclein expression in Ni-induced neurodegeneration.

Effect of fructo-oligosaccharide supplementation in soya beverage on the intestinal absorption of calcium and iron in newly weaned rats

Studies have shown the positive effects of prebiotics on the intestinal absorption of Ca and Fe. The present study evaluated the effect of fructo-oligosaccharide (FOS) supplementation in soya beverage (SB) on absorption mechanisms of Ca and Fe in recently weaned rats. Male Wistar rats were divided into four groups: lactose-free cows' milk (CM), lactose-free CM with FOS (0·8 g/100 ml) (CMF), SB and soya beverage with FOS (0·8 g/100 ml) (SBF). These rats were euthanised after 1 week of treatment. Organ weight, pH of the caecal content and absorption mechanisms of Ca and Fe were evaluated. The results showed that the weight of the caecal contents increased in the CMF and SBF groups, and the pH of the caecal contents was lower in these groups. The Hb levels of the CMF and SB groups were higher when compared with that of the CM group and lower in relation to the SBF group. The apparent Ca and Fe absorption and apparent Ca retention in the CM group were higher when compared with the SB group, whereas in the CMF group, they were higher in relation to the SBF group. Divalent metal transporter 1 (DMT1) protein expression in the duodenum was higher in the SBF group than in the SB and CMF groups. SB resulted in lower intestinal Ca absorption and higher Hb concentration, despite the lower apparent Fe absorption in relation to CM. Supplementation with FOS provided beneficial effects on Hb and DMT1 protein expression in the duodenum, in addition to improving the absorption process.

Dose response effects of postnatal hydrocortisone on growth and growth factors in the neonatal rat

BACKGROUND AND PURPOSE

Hydrocortisone (HC), at different dosages, is used in critically ill newborns for lung stability, blood pressure support, and prevention of chronic lung disease (CLD). Its long-term effects on postnatal growth are not well studied. We hypothesized that early exposure to high doses of HC adversely affects growth, growth factors, metabolic hormones, and neurological outcomes, persisting in adulthood.

EXPERIMENTAL DESIGN

Rat pups received a single daily intramuscular dose of HC (1 mg/kg/day, 5 mg/kg/day, or 10 mg/kg/day on days 3, 4 & 5 postnatal age (P3, P4, P5). Age-matched controls received equivalent volume saline. Body weight, linear growth, and neurological outcomes were monitored. Animals were sacrificed at P21, P45, and P70 for blood glucose, insulin, IGF-I, GH, leptin, and corticosterone levels. Liver mRNA expression of IGFs and IGFBPs were determined at P21 and P70. Memory and learning abilities were tested using the Morris water maze test at P70.

RESULTS

HC suppressed body weight and length at P12, P21 and P45, but by P70 there was catchup overgrowth in the 5 and 10 mg/kg/day groups. At P70 blood insulin, IGF-I, GH, and leptin levels were low, whereas blood glucose, and liver IGFs and IGFBPs were high in the high dose groups. High HC also caused delayed memory and learning abilities at P70.

CONCLUSIONS

These data demonstrate that while higher doses of HC may be required for hemodynamic stability and prevention of CLD, these doses may result in growth deficits, as well as neurological and metabolic sequelae in adulthood.

Regenerative potential of bone marrow mesenchymal stem cells on cadmium chloride-induced hepato-renal injury and testicular dysfunction in sprague dawley rats

The effect of bone marrow-derived mesenchymal stem cells on cadmium-induced liver and kidney damage was studied in Sprague Dawley rats. The study employed three animal groups: Group 1 served as control animals; Group 2 rats were dosed intra-peritoneally with 2 mg of cadmium chloride per kg body weight, and Group 3 rats were again dosed with a single intraperitoneal injection of 2 mg of cadmium chloride per kg body weight two doses of 10⁶ cells each intravenously. Finally, the animals were killed using halothane inhalation anesthesia. Semen analysis (total sperm count, viability, motility, and % of normal sperm), biochemical estimations (serum total protein, uric acid, creatinine, levels of enzymes ALT, AST, and ALP, and levels of hormones LH, FSH, Inhibin, and testosterone), and histopathological analysis of liver and kidney tissue sections (using hematoxylene and eosin stains) were conducted. The results showed that when compared to controls, cadmium exposure drastically decreased total sperm count, viability, motility, and % of normal sperm, decreased serum total protein, increased serum uric acid and creatinine levels, increased levels of ALT, AST, and ALP enzymes, decreased levels of testosterone and inhibin, increased levels of LH and FSH, and caused significant histopathological abnormalities in both kidney and liver tissues. Treatment with stem cells ameliorated the effects of cadmium-induced toxicity significantly (p < 0.05) of the histopathological and biochemical parameters. In conclusion, the study reinforces previous findings that bone marrow mesenchymal stem cells can ameliorate the toxic effects of cadmium chloride and may be used as a potential therapeutic strategy for cadmium-induced adverse effects.

Oral cadmium exposure affects skin immune reactivity in rats

Skin can acquire cadmium (Cd) by oral route, but there is paucity of data concerning cutaneous effects of this metal. Cd acquired by oral route can affect skin wound healing, but the effect of Cd on other activities involved in skin homeostasis, including skin immunity, are not explored. Using the rat model of 30-day oral administration of Cd (5 ppm and 50 ppm) in drinking water, basic aspects of immune-relevant activity of epidermal cells were examined. Dose-dependent Cd deposition in the the skin was observed (0.035 ± 0.02 µg/g and 0.127 ± 0.04 µg/g at 5 ppm and 50 ppm, respectively, compared to 0.012 ± 0.009 µg/g at 0 ppm of Cd). This resulted in skin inflammation (oxidative stress at both Cd doses and dose-dependent structural changes in the skin and the presence/activation of innate immunity cells). At low Cd dose inflammatory response (nitric oxide and IL-1β) was observed. Other inflammatory cytokines (IL-6 and TNF) response occurred at 50 ppm, which was increased further following skin sensitization with contact allergen dinitro-chlorobenzene (DNCB). Epidermal cells exposed to both Cd doses enhanced concanavalin A (ConA)-stimulated lymphocyte production of IL-17. This study showed for the first time the effect of the metal which gained access to the skin via gut on immune reactivity of epidermal cells. Presented data might be relevant for the link between dietary Cd and the risk of skin pathologies.

Systemic administration of curcumin or piperine enhances the periodontal repair: a preliminary study in rats

OBJECTIVES

Studies have documented the anti-inflammatory effects of spices, which may be related to treatment of chronic diseases. The purpose of this study was to evaluate the influence of curcumin and piperine and their association on experimental periodontal repair in rats.

MATERIALS AND METHODS

Periodontitis was induced via the installation of a ligature around the first molar. After 15 days, the ligatures were removed, and the rats were separated into groups (12 animals per group): (i) curcumin, (ii) piperine, (iii) curcumin+piperine, (iv) corn oil vehicle, and (v) control group (animals had ligature-induced periodontitis but were not treated). The compounds were administered daily, for 15 days by oral gavage. Animals were euthanized at 5 and 15 days, and hemimaxillae and gingival tissues were harvested. Bone repair was assessed by μCT (microcomputer tomography). Histological sections were stained with hematoxylin/eosin (H/E) for the assessment of cellular infiltrate or picrosirius red for quantification of collagen content, and subjected to immunohistochemistry for detecting NF-ĸB. Gingival tissues were used to evaluate levels of TGF-β and IL-10 (ELISA).

RESULTS

Curcumin and piperine increased the TGF-β level, significantly improved the collagen repair, and decreased the cellularity and activation of NF-ĸB in the periodontal tissues, but only curcumin caused a significant increase in early bone repair.

CONCLUSION

Curcumin and piperine promoted a substantive effect on tissue repair; however, there was not synergistic effect of compounds administered in combination.

CLINICAL RELEVANCE

Curcumin and piperine stimulates the tissue repair and may be potential candidates for the treatment of periodontal disease.

Dietary supplementation with L-lysine affects body weight and blood hematological and biochemical parameters in rats

L-Lysine (Lys) is a popular additive in foods, but the physiological effects of excess Lys supplementation are poorly understood and upper limits of safe intake have not been established. The objectives of this study were to examine the effects of dietary supplementation with increasing amounts of Lys on body weight (BW), food intake, and various blood hematological and biochemical parameters in rats. Male Sprague-Dawley rats at 10 weeks of age were assigned to ten diet groups (eight rats/group) and fed diets containing either 7% or 20% casein and supplemented with either 0% (Control), 1.5%, 3%, 6% Lys, or 6% Lys + 3% arginine for 1 week. Rats fed 7% casein with ≥ 1.5% Lys supplementation had lower serum albumin and leptin and higher LDL cholesterol (LDLC), ratios of total cholesterol (TC):HDL cholesterol (HDLC) and LDLC:HDLC than those fed 7% casein Control diet (P < 0.05). Rats fed 7% casein diet supplemented with 3% Lys diet had lower BW gain, food intake, serum alkaline phosphatase activity, and increased mean corpuscular hemoglobin concentration, blood urea nitrogen and serum pancreatic polypeptide compared to rats fed the Control diet (P < 0.05). Addition of 6% Lys in 7% casein caused significant BW loss (P < 0.001) and altered additional parameters. Addition of 6% Lys in a 20% casein diet reduced BW gain and food intake and altered numerous parameters. Arg supplementation normalized many of the endpoints changed by Lys. Collectively, these results show that Lys supplementation affects BW, food intake and a number of hematological and biochemical parameters. These effects of Lys supplementation were confined primarily in diets with lower levels of dietary protein. In the context of a low protein diet (7% casein), levels of Lys supplementation ≥ 1.5% may exert adverse health effects in rats.