The Effects of Fluoride on the Gap-Junctional Intercellular Communication of Rats’ Osteoblast

Biological Trace Element Research - The gap junction protein plays an important role in the bone formation and alteration of these proteins leading to cause bone development. Aim to determine the...     

Tetramethylpyrazine Ameliorates Rotenone-Induced Parkinson’s Disease in Rats: Involvement of Its Anti-Inflammatory and Anti-Apoptotic Actions

Parkinson’s disease (PD) is a slowly progressive neurodegenerative movement disorder. Apoptosis, neuroinflammation, and oxidative stress are the current hypothesized mechanisms for PD pathogenesis. Tetramethylpyrazine (TMP), the major bioactive component of Ligusticum wallichii Franchat (ChuanXiong), Family Apiaceae, reportedly has anti-apoptotic, anti-inflammatory and antioxidant effects. This study investigated the role of ‘TMP’ in preventing rotenone-induced neurobiological and behavioral sequelae. A preliminary dose–response study was conducted where rats received TMP (10, 20, and 40 mg/kg, i.p.) concomitantly with rotenone (2 mg/kg, s.c.) for 4 weeks. Catalepsy, locomotor activity, striatal dopamine content, and tyrosine hydroxylase “TH” and α-synuclein immunoreactivity were evaluated. The selected TMP dose (20 mg/kg) was used for western blot analysis of Bax, Bcl2, and DJ-1, immunohistochemical detection of nuclear factor kappa B (NF-кB), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX2), and glial fibrillary acidic protein (GFAP) expression, in addition to biochemical analysis of caspase-3 activity, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) levels. Results showed that TMP (20 mg/kg) significantly improved midbrain and striatal TH expression and striatal dopamine content as well as the motor deficits, compared to rotenone-treated group. These results were correlated with reduction in caspase-3 activity and α-synuclein expression, along with improvement of midbrain and striatal Bax/Bcl2 ratio compared to rotenone-treated group. TMP also attenuated rotenone-induced upregulation of Nrf2/HO-1 pathway. Furthermore, TMP downregulated rotenone-induced neuroinflammation markers: NF-кB, iNOS, COX2, and GFAP expression in both the midbrain and striatum. Taken together, the current study suggests that TMP is entitled to, at least partially, preventing PD neurobiological and behavioral deficits by virtue of its anti-apoptotic, anti-inflammatory, and antioxidant actions.     

Effects of Cadmium Chloride and Sodium Selenite Alone or in Combination on the Liver of Male Sprague–Dawley Rats Assessed by Different Assays

This study assessed the impact of either cadmium chloride (Cd) or sodium selenite (Se) alone or in combination on male Sprague–Dawley rats. For this purpose, body and liver weights, comet and TUNEL assays, histological analysis and levels of lipid peroxidation and antioxidants in liver were determined in four groups of male Sprague–Dawley rats. The rats were given subcutaneous doses of 1 mg/kg body weight (BW) of either normal saline (control = Ct) or Cd or Se or Cd plus Se (Cd + Se) on alternate days for 4 weeks. The Cd group showed increased DNA damage, apoptosis and hepatic levels of lipid peroxidation and altered histology. Conversely, the antioxidant levels in this group were decreased as compared with the control group. The Se group also showed DNA damage, apoptosis and altered histology and reduced catalase activity, but it was less severe than the Cd group. In the Cd + Se group, ameliorating effects of Se on Cd-induced changes were observed. While the Se was able to curtail the toxic effect of Cd, the Cd or Se alone were genotoxic and cytotoxic for rats receiving a high pharmacological but non-fatal dose of 1 mg/kg BW.     

Effects of Pyrazinamide on Tryptophan–Niacin Conversion in Rats

In the course of our screening for a new anti-tumor substance, the bisabolane sesquiterpenoid endoperoxide, 3,6-epidioxy-1,10-bisaboladiene (EDBD), was isolated from the edible wild-plant, Cacalia delphiniifolia. EDBD showed cytotoxicity toward human chronic myelogenous leukemia K562 and human prostate carcinoma LNCaP cell lines with IC₅₀ values of 9.1 μM and 23.4 μM, respectively. DNA fragmentation and condensation of chromatin, the hallmarks of apoptosis, appeared in K562 cells after an 18-h treatment with EDBD. α-Curcumene, a bisabolane sesquiterpene that lacks the endoperoxide moiety of EDBD, also showed cytotoxicity toward both K562 and LNCaP cell lines at over a 10-times higher dose than that of EDBD. The results indicate the importance of the endoperoxide structure within EDBD to its anti-tumor activity in vitro.     

Effects of Kidnev—Tonifing, Herbs on the Glucocorticoid Receptor （GR） mRNA Expression in Hil~l~ocamDalSubfieldsofAging, Rats

Ginkgolides (Gin), mainly including A, B, C, J, M and belonging to terpene lactone are one of the main active constituents in the extractof leaves of Ginkgo biloba L. Gin B is a specific and potent antagonist of platelet-activating factor (PAF). Some animal and clinical data showthe potential anti-ischemic/hypoxic effects and obvious protective effects of Gin on neurons, however the mechanisms of which and specially     

An Investigation Into the Effects of Long-Term 50-Hz Power-Frequency Electromagnetic Field Exposure on Hematogram,Blood Chemistry,Fibrosis, and Oxidant Stress Status in the Liver and the Kidney From Sprague–Dawley Rats

Power-frequency electromagnetic fields (PF-EMFs) at 50 Hz are potential health risk factors. This study aimed to explore the effects of long-term exposure to 50-Hz PF-EMFs on general physiological conditions in Sprague–Dawley (SD) rats. During a 24-week exposure period, the body mass and water and food intake of the animals were recorded regularly. The hematologic parameters were detected every 12 weeks, and blood chemistry analyses were performed every 4 weeks. After sacrifice, morphology was identified by hematoxylin–eosin, Masson, and immunohistochemical staining. Fibrosis-related gene expression and oxidative stress status were also detected. Compared with the control group, exposure to 30, 100, or 500 μT PF-EMF did not exert any effect on body mass, food intake, or water intake. Similarly, no significant differences were found in hematologic parameters or blood chemistry analyses among these groups. Furthermore, morphological assays showed that exposure to PF-EMFs had no influence on the structure of the liver or kidney. Finally, fibrosis-related gene expression and oxidative stress status were unaltered by PF-EMF exposure. The present study indicates that 24 weeks of exposure to PF-EMFs at intensities of 30, 100, or 500 μT might not affect hemograms, blood chemistry, fibrosis, or oxidative stress in the liver or kidney in SD rats. © 2020 Bioelectromagnetics Society     

Ameliorated Effects of (−)-Epigallocatechin Gallate Against Toxicity Induced by Vanadium in the Kidneys of Wistar Rats

Obesity is a chronic disease characterized by excessive accumulation of body fat and the presence of metabolic disorders such as insulin resistance. In this sense, zinc is an important nutrient that stimulates insulin secretion and increases sensitivity to insulin. The aim of this study was to investigate the effect of zinc supplementation on insulin resistance in obese subjects through a systematic review of the available clinical trials. The search for articles was conducted using the PubMed, SciVerse Scopus, SciVerse ScienceDirect, and Cochrane databases, on May 25, 2016, by two authors independently. The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were followed in the conduct of this review. The Cochrane Collaboration tool was used to assess the risk of bias of the trials included in this review. After screening of the articles, six clinical trials were included in this systematic review. The scientific evidence presented in this systematic review shows that zinc supplementation improves insulin resistance in obese individuals of both sexes.     

Changes of α-Glycerophosphate Dehydrogenase Activity in Fatty Liver of Rats by Amino Acid Imbalance

An aminopeptidase was purified from an aqueous extract of mullet roe in the presence of 2-mercaptoethanol by fractionation with ammonium sulfate and column chromatography on DEAE-cellulose and Sephadex G-200. The molecular weight of the enzyme was 184,000 by gel filtration, and the enzyme appeared to consist of two homogenous subunits. The optimal pH and optimal temperature for activity were 7.4 and 45°C, respectively. Puromycin, p-chloromercuribenzoic acid, and o-phenanthroline inhibited the enzyme n on-competitively (their Ki = 1.34 μm, 0.113mm and 0.145 mm, respectively), while 2-mercaptoethylamine was competitive (Ki = 0.056 mm). The enzyme was also inhibited by l-amino acids, in particular glutamic acid. The enzyme could hydrolyze a variety of α-aminoacyl β-naphthylamides and was most active on l-alanyl-β-naphthylamide. Judging from these properties, the mullet roe aminopeptidase resembles soluble alanyl amino-peptidase [EC 3.4.11.14].     

The NLRP3 Inflammasome is Involved in the Pathogenesis of Parkinson’s Disease in Rats

The etiology and pathogenesis of Parkinson’s disease (PD) are complicated and have not been fully elucidated, but an important association has been identified between inflammation and PD. In this study, we investigated the role of the nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain-containing (NLRP) 3 inflammasome, consisting of NLRP3, caspase-1 and cytokines of the IL-1 family, in lipopolysaccharide (LPS)-induced and 6-hydroxydopamine (6-OHDA)-induced PD rats. Microinjection of different doses of caspase-1 inhibitor (Ac-YVAD-CMK, 300 or 1200 ng/rat) was performed for seven consecutive days. Then, rotational behavior, the number of dopamine (DA) neurons in the substantia nigra pars compacta (SNc), and the mRNA and protein expression levels of NLRP3 inflammasome components were measured 14 days after the microinjection setup was established. Results showed that high mRNA and protein expression levels of NLRP3 inflammasome components were observed in the injected side of the LPS- and 6-OHDA-induced PD rats; Ac-YVAD-CMK inhibited the mRNA and protein expression of NLRP3 inflammasome components in both LPS- and 6-OHDA-induced PD rats. Moreover, the number of rotations was significantly decreased, and the number of DA neurons in the SNc improved. Our data indicate that the NLRP3 inflammasome participates in the pathogenesis of PD and that inhibiting the downstream pathway of the NLRP3/caspase-1/IL-1β axis can alleviate the occurrence of PD symptoms, providing a new basis for the prevention and treatment of PD.     

Have the Harmful Effects of Introduced Rats on Islands been Exaggerated?

Introduced rats are now being eradicated from many islands. Increasingly, these eradications are contested by activists claiming moral, legal, cultural, historic or scientific reasons and poorly documented evidence of effects. We reviewed the global literature on the effects of rats on island flora and fauna. We then used New Zealand as a case study because of its four-decade history of rat eradications and many detailed and innovative studies of how rats affect native species. These include use of exclosures, local manipulations of rat populations, video surveillance, and measurements of responses following eradications. The most intensive studies have been on the Pacific rat (Rattus exulans), a small South-East Asian species spread by Polynesians throughout the Pacific. These and the more recently introduced Norway rat (R. norvegicus) and ship (roof) rat (R. rattus) suppress some forest plants, and are associated with extinctions or declines of flightless invertebrates, ground-dwelling reptiles, land birds, and burrowing seabirds. On islands off France, Norway rats are also implicated in declines of shrews. Globally, ship rats were associated with declines or extinctions of the largest number of indigenous vertebrate species (60), including small mammals such as deer mice and bats. Effects of rats on forest trees and seabird populations are sufficiently pervasive to affect ecosystem structure and function. However, the data are patchy. Deficiencies in our knowledge would be reduced by documenting distribution and abundance of indigenous species before and after eradications. Comprehensive measurements of the responses of indigenous species to rat eradications would enable the development of testable models of rat invasion effects.     

Effects of α-Tocopherol on Carbon Tetrachloride Metabolism in Rat Liver Microsomes

α-tocopherol is the major lipid-soluble radical-scavenging antioxidant in rat liver. It has long been used as a putative protective agent in CC1₄ induced liver injury but with variable results. We have used a-tocopherol loaded rat liver microsomes to study the effect of this vitamin on CC1₄ metabolism in vitro. As expected, a-tocopherol inhibits CC1₄-dependent microsomal lipid peroxidation and, at a very high concentration, will inhibit the covalent binding of CC1,- to microsomal protein by up to 50%. No inhibitory effect was observed towards CC1₃ production as measured by the electron spin resonance technique of spin-trapping but this apparent discrepancy may represent a limitation of the technique. The high levels required to inhibit covalent binding probably preclude the likelihood of a-tocopherol significantly affecting that phenomenon at endogenous concentrations but may be relevant to other experiments employing high doses of a-tocopherol as an experimental hepatoprotective agent.     

Effects of Peroxidation Products of Linoleic Acid on Tryptophan–nicotinamide Metabolism in Rats

The flavin and pyridine nucleotide coenzymes are involved in the detoxication of autoxidation products of lipids. In tryptophan-nicotinamide metabolism, kynurenine 3-hydroxylase and N¹-methylnicotinamide (MNA) oxidase contain FAD as a coenzyme. So, the effects of dietary autoxidation products of linoleic acid on the metabolism of tryptophan-nicotinamide were investigated using rats. The administration of linoleic acid hydroperoxides or secondary products reduced the urinary excretion of xanthurenic acid, nicotinamide and its metabolites such as MNA, N¹-methyl-2-pyridone-5-carboxamide (2-Py), and N¹-methyl-4-pyridone-3-carboxamide (4-Py) as compared with the group administered saline or linoleic acid. Among the enzyme activities involved in the tryptophan-nicotinamide metabolism, the activity of NAD⁺ synthetase was decreased by the administration of linoleic acid hydroperoxides or secondary products. The activities of tryptophan oxygenase and 4-Py-forming MNA oxidase were also decreased by the administration of secondary products. These results indicate that the conversion of tryptophan to nicotinamide would be lower in the groups administered the hydroperoxides and secondary products than in saline and linoleic acid groups.     

Intraoperative Biomechanical Registration of the Liver: Does the Heterogeneity of the Liver Matter?

Background: Preoperative images such as computed tomography scans or magnetic resonance imaging contain lots of valuable information that are not easily available for surgeons during an operation. To help the clinicians better target the structures of interest during an intervention, many registration methods that align preoperative images onto the intraoperative view of the organs have been developed. For important organ deformation, biomechanically-based registration has proven to be a method of choice.Method: Using an existing biomechanically-based registration algorithm for laparoscopic liver surgery we investigate in this paper the influence of the heterogeneity of the liver on the registration result.Results: No statistical difference in the results was found between the registration performed with the homogeneous model and the one carried out with the heterogeneous model.Conclusion: As the use of an heterogeneous model does not improve significantly the registration result and increase the computation time we recommend to perform the type of registration task described in the paper with a simplified homogeneous model.     

Effects of Fluoride and/or Sulfur Dioxide on Morphology and DNA Integrity in Rats’ Hepatic Tissue

This study was aimed to evaluate the toxic effects of fluoride (F) and/or sulfur dioxide (SO₂) on morphology and DNA integrity in liver of male rats. For this, 96 Wistar rats (12-week-old) were randomly divided into four groups after 1-week adaptive breeding: the control group, treated with deionized water; the NaF group, administered high F (100 mg NaF/L in the drinking water); the SO₂ group, with sulfur dioxide in ambient air (15 ppm SO₂, 4 h/day); and NaF + SO₂ group, treated with high F and sulfur dioxide together for 8 consecutive weeks. The body weight, liver organ coefficient, morphology, and DNA damage in the liver of rats were examined. The results showed that the body weight and liver organ coefficient were not significantly changed; however, significant pathological changes of liver tissues were observed in the NaF + SO₂ group compared with the individual treated groups and control group. Furthermore, comet assay indicated that DNA damage in liver was significantly increased in the F and/or SO₂ treatment groups at 2, 4, 6, and 8 weeks, especially at 4 weeks. These results indicate that the liver morphology and DNA integrity of rats are adversely affected by F and/or SO₂ exposure.