Sex-specific effects of fluoride and lead exposures on histology, antioxidant physiology, and immune system in the liver of zebrafish (Danio rerio).

Fluoride and Pb are both toxic to organisms; however, their combination effects and the corresponding toxic mechanisms remain unclear. In this study, male and female zebrafish (1:1) were evaluated to understand the effects of F and Pb alone and combined on growth, tissue microstructure, oxidative stress, and immune system functions of the liver. Four different groups and two exposure periods were compared: control group (C group), 80 mg/L fluoride group (F group), 60 mg/L lead group (Pb group), and 80 mg/L fluoride + 60 mg/L lead group (F + Pb group) for 45 and 90 days. The results indicated that F and Pb reduced growth performances; F + Pb treatment inhibited the growth performance traits of male zebrafish more than those of female zebrafish. Histopathological examination revealed large areas with focal necrosis, hepatocytes with karyolysis, and pycnotic nuclei in zebrafish exposed to F and Pb. The oxidative balance indices in the liver in the F and Pb groups were disturbed. F + Pb co-exposure aggravated oxidative stress in a time-dependent manner. The most serious oxidative stress was observed in the male zebrafish of the F + Pb group. Moreover, F and Pb exposure of male zebrafish increased pro-inflammatory and anti-inflammatory cytokines expression, which was decreased after 90 days of exposure. These results demonstrated that both F and Pb could damage the liver via downstream alterations in the activities of immune-related enzymes and in the levels of immune-related genes. F and Pb showed synergistic or additive effects. Male zebrafish were found to be more sensitive to F and Pb than female zebrafish.

The Effects of a High-Fat/Cholesterol Diet on the Intestine of Rats Were Attenuated by Sparassis latifolia Polysaccharides.

Research background: Sparassis latifolia polysaccharides can regulate lipids and cholesterol in serum and liver. However, little is known about the regulation mechanism of the polysaccharides on cholesterol metabolism and especially the causal relationship with gut microbiota regulation. This study will provide a theoretical basis for the cholesterol-lowering mechanism of S. latifolia polysaccharides and further development of functional foods. Experimental approach: In this study, we investigated how the regulation mechanism of Sparassis latifolia polysaccharides affects intestinal cholesterol metabolism in high-fat and high-cholesterol diet-fed rats. Briefly, enzymatic colorimetric microplate assay was used to determine the concentration of faecal bile acid. Gas chromatography-mass spectrometry was used to detect the content of cholesterol and alcohol in faeces. Haematoxylin and eosin staining method was applied to observe the changes in the structure of the small intestine tissue. The related gene expressions in jejunum and ileum were detected by real-time fluorescent quantitative polymerase chain reaction. The related protein expressions in jejunum were studied by using Western blot. High-throughput sequencing was used to detect the intestinal flora changes of the caecal contents. Gas chromatography-mass spectrometry was applied to detect the concentration of short-chain fatty acids in the caecal content. Results and conclusions: The results showed that Sparassis latifolia polysaccharides could improve the intestinal morphological structure and physiological indices in rats fed high-fat and high-cholesterol diet. Moreover, it could improve intestinal cholesterol metabolism disorder induced by high-fat and high-cholesterol diets via the reduction of the expression of HMGCR, NPC1L1, ACAT2, MTP, ASBT and IBABP mRNA or protein, increasing ABCG8 mRNA expression. In addition, it could also increase the relative abundance of Bacteroides, Butyricicoccus, Parabacteroides, Parasutteerella and Alloprevotella and the short-chain fatty acid concentration, to comprehensively regulate the intestinal cholesterol metabolism. The metabolomics analysis found that Sparassis latifolia polysaccharides could affect lipid, carbohydrate and other related metabolites. Some biomarkers associated with cholesterol metabolism correlated significantly with the abundance of specific intestinal microbiota. Novelty and scientific contribution: These findings indicate that Sparassis latifolia polysaccharides could attenuate intestinal cholesterol metabolism disorder, correlating with modulating gut microbiota and improving host metabolism. They provide theoretical support for the development of Sparassis latifolia as a new food resource.

Sesamin attenuates histological alterations, oxidative stress and expressions of immune-related genes in liver of zebrafish (Danio rerio) exposed to fluoride.

Sesamin is the main lignan in sesame and is reported to have many benefits and medicinal properties. However, its protective effects against fluoride-induced damage in the liver of zebrafish have not been elucidated. Our previous studies found that fluoride exposure caused damage to the liver of zebrafish. In the study, the effects of sesamin on oxidative stress and immune damage in liver of zebrafish exposed to fluoride were measured. The results indicated that fluoride exposure damaged the microstructures of liver, increased significantly the oxidative stress, decreased remarkably the activities of ACP, AKP, and LZM, and affected obviously the expressions of immune-related genes. Treatment with sesamin remarkably attenuated fluoride-induced liver damage in a dose-dependent manner, indicated by the histopathological observation. Furthermore, sesamin treatment also significantly inhibited the production of ROS and oxidative stress, such as the decrease of lipid peroxidation level and the increase of CAT and SOD activities in liver. Sesamin treatment reversed the activities of immune-related enzymes and the expressions of immune-related genes in liver exposed to fluoride. These findings suggested that sesamin could protect the liver from fluoride-induced immune damage by oxidative stress downstream-mediated changes in reversing the activities of immune-related enzymes and the expressions of immune-related genes. Taken together, sesamin plays an important role in maintaining hepatic health and preventing liver from toxic damage caused by fluoride.

Stability and iron oxidation properties of a novel homopolymeric plant ferritin from adzuki bean seeds: a comparative analysis with recombinant soybean seed H-1 chain ferritin.

BACKGROUND: All reported plant ferritins are heteropolymers comprising two different H-type subunits. Whether or not homopolymeric plant ferritin occurs in nature is an open question. METHODS: A homopolymeric phytoferritin from adzuki bean seeds (ASF) was obtained by various protein purification techniques for the first time, which shares the highest identity (89.6%) with soybean seed H-1 ferritin (rH-1). Therefore, we compared iron oxidation activity and protein stability of ASF with those of rH-1 by stopped-flow combined with light scattering or UV/Vis spectrophotography, SDS- and native- PAGE analyses. Additionally, a new rH-1 variant (S68E) was prepared by site-directed mutagenesis approach to elucidate their difference in protein stability. RESULTS: At high iron loading of protein, the extension peptide (EP) of plant ferritin was involved in iron oxidation, and the EP of ASF exhibited a much stronger iron oxidative activity than that of rH-1. Besides, ASF is more stable than rH-1 during storage, which is ascribed to one amino acid residue, Ser68. CONCLUSIONS: ASF exhibits a different mechanism in iron oxidation from rH-1 at high iron loading of protein, and a higher stability than rH-1. These differences are mainly stemmed from their different EP sequences. GENERAL SIGNIFICANCE: This work demonstrates that plant cells have evolved the EP of phytoferritin to control iron chemistry and protein stability by exerting a fine tuning of its amino acid sequence.

Structure, function, and nutrition of phytoferritin: a newly functional factor for iron supplement.

Ferritins are members of the superfamily of iron storage and detoxification proteins present in all living organisms and play important roles in controlling cellular iron homeostasis. In contrast to animal ferritin, relatively little information is available on the structure and function of phytoferritin. Phytoferritin is observed in plastids whereas animal ferritins are largely found in the cytoplasm of cell. Compared to animal ferritin, phytoferritin exhibits two major distinctive features in structure. First, phytoferritin contains a specific extension peptide (EP) at the N-terminal while animal ferritin lacks it. The EP is located on the exterior surface of protein, which recently has been found to act as a second ferroxidase center for iron-binding and oxidation, and regulate iron release during the germination and early growth of seedlings. Second, only H-type subunit has been identified in phytoferritin, which is usually a heteropolymer consisting of two different subunits, H-1 and H-2, sharing ~80% amino acid sequence identity. These two subunits in phytoferritin play a positively cooperative role in iron oxidative deposition in protein. Iron deficiency anemia (IDA) is the most common and widespread nutritional disorder in the world, so it is crucial to explore a safe and efficient functional factor for iron supplement. Fortunately, phytoferritin seems to be a suitable candidate. In legume seeds, more than 90% of iron is stored in the form of ferritin in amyloplasts. Recently, some studies at different levels have demonstrated that plant ferritin could be used as novel, utilizable, plant-based forms of iron for populations with a low iron status. This review focuses on recent progress in structure, function, and nutrition of phytoferritin.

Water-in-oil Pickering emulsion using ergosterol as an emulsifier solely.

As a crucial component of the fungal cell membranes, ergosterol has been demonstrated to possess surface activity attributed to its hydrophobic region and polar group. However, further investigation is required to explore its emulsification behavior upon migration to the oil-water interface. Therefore, this study was conducted to analyze the interface properties of ergosterol as a stabilizer for water in oil (W/O) emulsion. Moreover, the emulsion prepared under the optimal conditions was utilized to load the water-soluble bioactive substance with the chlorogenic acid as the model molecules. Our results showed that the contact angle of ergosterol was 117.017°, and its dynamic interfacial tension was obviously lower than that of a pure water-oil system. When the ratio of water to oil was 4: 6, and the content of ergosterol was 3.5 % (ergosterol/oil phase, w/w), the W/O emulsion had smaller particle size (438 nm), higher apparent viscosity, and better stability. Meanwhile, the stability of loaded chlorogenic acid was improved under unfavorable conditions (pH 1.2, 90 °C, ultraviolet irradiation, and oxidation), which were 73.87 %, 59.53 %, 62.53 %, and 69.73 %, respectively. Additionally, the bioaccessibility of chlorogenic acid (38.75 %) and ergosterol (33.69 %), and the scavenging rates of the emulsion on DPPH radicals (81.00 %) and hydroxyl radicals (82.30 %) were also enhanced. Therefore, a novel W/O Pickering emulsion was prepared in this work using ergosterol as an emulsifier solely, which has great potential for application in oil-based food and nutraceutical formulations.

The Effects of Naematelia aurantialba on the Pasting and Rheological Properties of Starch and the Research and Development of Soft Candy.

To study the effects of Naematelia aurantialba (NA) on the rheological and gelatinization properties of starch, the processing methods of NA were diversified. In this study, the gelatinization and rheological properties of corn starch (CS) and edible cassava starch (ECS) were investigated by adding NA with different mass fractions. Starch soft candy was prepared using NA, CS, and ECS as the main raw materials. Rheological studies showed that both CS-NA and ECS-NA exhibited elastic modulus (G') > viscosity modulus (G″), implying elastic behavior. G' was such that CS+1%NA > CS+5%NA > CS+3%NA > CS > CS+2%NA > CS+4%NA > ECS+4%NA > ECS+3%NA > ECS+5%NA > ECS+2%NA > ECS+1%NA > ECS. The gelatinization implied showed that after adding NA, the pasting temperature of CS-NA and ECS-NA increased by 1.33 °C and decreased by 2.46 °C, while their breakdown values decreased by 442.35 cP and 866.98 cP, respectively. Through a single-factor test and orthogonal test, the best formula of starch soft candy was as follows: 0.4 f of NA, 10 g of white granulated sugar, a mass ratio of ECS to CS of 20:1 (g:g), 0.12 g of citric acid, 1 g of red date power, and 16 mL of water. The soft candy was stable when stored for two days. This study offers a new direction for the research and development of NA starch foods.

Investigation of Consequences of High-Voltage Pulsed Electric Field and TGase Cross-Linking on the Physicochemical and Rheological Properties of Pleurotus eryngii Protein.

This study aimed to evaluate the effects of high-voltage pulsed electric fields (HPEF) and transglutaminase (TGase) cross-clinking on the physicochemical and rheological properties of Pleurotus eryngii protein (PEP). The results showed that HPEF increased α-helixes and ß-turns but decreased ß-folds. A HPEF at 1500 V/cm maximized the free sulfhydryl content and solubility of PEP. TGase formed high-molecular-weight polymers in PEP. TGase at 0.25% maximized the free sulfhydryl groups, particle size, and solubility; shifted the maximum absorption wavelength from 343 nm to 339 nm and 341 nm; increased α-helixes and ß-turns and decreased ß-folds; and showed better rheological properties. Compared with TGase cross-linking, HPEF-1500 V/cm and 1% TGase significantly reduced the free sulfhydryl groups, particle size, and solubility, produced more uniform network structures, and improved the rheological properties. These results suggest that HPEF can increase the cross-linking of TGase and improve rheological properties of TGase-cross-linked PEP by affecting the physicochemical properties.

Transglutaminase-Catalyzed Glycosylation Improved Physicochemical and Functional Properties of Lentinus edodes Protein Fraction.

Lentinula edodes has high nutritional value and abundant protein. In order to develop and utilize edible mushroom protein, this study was designed to investigate the effects of TGase-catalyzed glycosylation and cross-linking on the physicochemical and functional properties of Lentinus edodes protein fraction. The results showed that within a certain time, glycosylation and TGase-catalyzed glycosylation decreased the total sulfydryl, free sulfydryl, disulfide bond, surface hydrophobicity, ß-fold and α-helix, but increased the fluorescence intensity, random coil, ß-turn, particle size and thermal stability. The apparent viscosity and the shear stress of the protein with an increase in shear rate were increased, indicating that TGase-catalyzed glycosylation promoted the generation of cross-linked polymers. In addition, the TGase-catalyzed glycosylated proteins showed a compact texture structure similar to the glycosylated proteins at the beginning, indicating that they formed a stable three-dimensional network structure. The flaky structure of proteins became more and more obvious with time. Moreover, the solubility, emulsification, stability and oil-holding capacity of enzymatic glycosylated Lentinus edodes protein fraction were significantly improved because of the proper TGase effects of glycosylation grafting and cross-linking. These results showed that glycosylation and TGase-catalyzed glycosylation could improve the processing characteristics of the Lentinula edodes protein fraction to varying degrees.

Sparassis latifolia polysaccharides inhibit colon cancer in mice by modulating gut microbiota and metabolism.

Sparassis latifolia polysaccharides (SLPs) can regulate inflammatory cytokines. However, little is known about the regulation mechanism of SLPs on colon cancer. In this study, we investigated the mechanism of SLPs on metabolism in mice with colon cancer. The results showed that SLPs could improve the colon morphology and physiological indices, and inhibit the infiltration of immune cells in colon. Moreover, it could improve metabolism disorder of colon cancer via reducing the levels of TNF-α, IL-6, NF-κB, COX-2 and IL-1ß mRNA or protein, increasing IκB mRNA or protein expression. In addition, it could comprehensively regulate the colon cancer related metabolism by changing the abundance of key intestinal flora and 35 metabolites including phosphatidylcholine, tryptophan and tetrahydrobiopterin. Some biomarkers associated with colon cancer metabolism were related significantly with the abundance of specific intestinal flora. These findings indicate that SLPs can attenuate metabolism disorder of colon cancer by modulating gut microbiota and metabolites.

Polysaccharide from Sparassis latifolia alleviates intestinal barrier dysfunction in mice exposed to lead.

Exposure to lead can have harmful effects on the intestines and gut microbiota, leading to toxicity. This study aimed to explore the protective role of Sparassis latifolia polysaccharide (SLP) in safeguarding the intestinal barrier of Kunming mice exposed to lead. The findings indicated that SLP effectively alleviates intestinal lesions, increases the density of cupped cells in the intestine, and reduces inflammation in both serum and the small intestine. Furthermore, SLP maintains the expression of key genes such as ZO-1, Occludin, Claudin-1, Lyz, Ang4, and ZO-2, as well as proteins like claudin-1 and Occludin-1. Furthermore, SLP positively impacts the diversity and richness of microorganisms in the mouse gut microbiota at both the genus and gate levels. It also increases the levels of short-chain fatty acids (SCFAs), including acetic acid, butyric acid, and propionic acid, to varying degrees. In summary, SLP plays a role in alleviating the impaired small intestinal barrier in lead-exposed mice by modulating the intestinal flora, which is consistent with reduced lead absorption. This modulation enhances the integrity of the intestinal barrier, suppresses inflammation, and facilitates the excretion of lead.

Sex-specific effects of fluoride and lead on thyroid endocrine function in zebrafish (Danio rerio).

Fluoride (F) and lead (Pb) are widespread pollutants in the environment. F and Pb affect the thyroid endocrine system, but the mechanism of action between F and Pb is still unclear. In this study, in order to evaluate the effects of F or/and Pb on histopathological changes, antioxidant indices, the levels of thyroid hormones (THs), and the expression of endocrine-related genes in zebrafish thyroid. One thousand and two hundred zebrafish (female:male = 1:1) were randomly divided into four groups: control group (C group), 80 mg/L F group (F group), 60 mg/L Pb group (Pb group), and 80 mg/L F + 60 mg/L Pb group (F + Pb group) for 45 d and 90 d. Histopathological sections showed a loss of glia and follicular epithelial hyperplasia in the thyroid gland after exposure to F and Pb. Oxidative stress in the thyroid was induced after F and Pb exposure. And each oxidation index was increased after F + Pb exposure. Combined F and Pb exposure aggravated the downregulation of thyroid hormones T3 and T4 compared to exposure alone. Furthermore, F and Pb exposure altered the expression of thyroid endocrine-related genes in a time-dependent manner. These results indicate that F and Pb can affect the endocrine system of thyroid by changing the tissue structure, antioxidant capacity, thyroid hormone secretion and the levels of endocrine-related genes in thyroid. F and Pb can also produce toxic effects on thyroid, but the degree of poisoning is different in different indicators, mainly for the additive effect between them. Additionally, males are more sensitive than females to F or Pb toxicity. However, the specific molecular mechanism of the effects of F and Pb on thyroid endocrine system needs to be further studied.

Selenomethionine alleviated fluoride-induced toxicity in zebrafish (Danio rerio) embryos by restoring oxidative balance and rebuilding inflammation homeostasis.

Fish are target organisms that are extremely susceptible to fluoride pollution, and an increase in fluoride load will damage multiple systems of fish. Selenomethionine (Se-Met) at low levels has been reported to alleviate oxidative damage and inflammation caused by toxic substances, but whether it can alleviate fluoride-induced toxicity in zebrafish embryos has not been elucidated. In this study, the intervention effects of Se-Met on developmental toxicity, oxidative stress and inflammation in zebrafish embryos exposed to fluoride were determined. Our results showed that fluoride accumulated in larvae and induced developmental toxicity in zebrafish embryos, caused oxidative damage and apoptosis, increased significantly the MPO and LZM activities and the levels of the inflammation-related genes IL-1ß, IL-6, TNF-α, IL-10 and TGF-ß. Moreover, fluoride significantly increased the levels of ERK2, JNK, p38 and p65 in MAPKs and NF-κB pathways. Se-Met-treatment alleviated the adverse effects induced by fluoride, and all of the above indicators induced by fluoride returned to near control levels with increasing concentrations and time. However, treatment with Se-Met-alone also markedly increased the levels of IL-6, TNF-α, IL-10, TGF-ß, ERK2 and JNK. In short, these data demonstrated that Se-Met-could alleviate fluoride-induced toxicity in zebrafish embryos by restoring oxidative balance and rebuilding inflammation homeostasis, although low levels of Se-Met-alone had certain toxic effects on zebrafish embryos. Taken together, Se-Met-plays an important role in preventing toxic damage induced by fluoride in zebrafish embryos, although it has certain toxic effects.

Effects of Sparassis latifolia neutral polysaccharide on immune activity via TLR4-mediated MyD88-dependent and independent signaling pathways in RAW264.7 macrophages.

Background: Sparassis latifolia (S. latifolia) is a precious edible fungus with multiple biological activities. To date, no study has been investigated the underlying molecular mechanism of immunoregulation caused by the neutral polysaccharide of S. latifolia. Materials and methods: To investigate immunomodulatory mechanism of S. latifolia neutral polysaccharide (SLNP), SLNP was obtained from S. latifolia and its structure, immune receptors and regulation mechanism were studied. Results: S. latifolia neutral polysaccharide consisted of arabinose, galactose, glucose, xylose, and mannose with a molar ratio of 6:12:63:10:5. SLNP was a pyran polysaccharide with a relative molecular weight of 3.2 × 105 Da. SLNP promoted the proliferation of RAW264.7, which further induced the secretions of nitric oxide, TNF-α, IL-6, and IFN-ß, and upregulated the immune receptor TLR4 expression. Moreover, SLNP increased remarkably the levels of TRAF6, IRF3, JNK, ERK, p38, and p38 mRNA and protein mediated by TLR4. Conclusion: S. latifolia neutral polysaccharide regulated the immune function of RAW264.7 through MyD88-dependent and -independent signaling pathways mediated by TLR4 receptor, which suggests that SLNP is a new immunomodulator.

Proanthocyanidins inhibit iron absorption from soybean (Glycine max) seed ferritin in rats with iron deficiency anemia.

The objective of this study was to evaluate the effect of proanthocyanidins (PAs) on iron uptake from soybean seed ferritin (SSF) crude by rats with iron deficiency anemia (IDA) for the first time. Six groups of Sprague-Dawley (SD) rats (n = 10) were used, which contain (1) SSF crude group; (2) SSF crude + PAs group; (3) PAs group; (4) FeSO(4) group; (5) iron deficiency control group; and (6) control group. The bioavailability of iron was examined by measuring hemoglobin (Hb) concentration value, red blood cell (RBC) numbers, and serum iron stores. After 8 weeks, Hb concentration was almost recovered to the normal level upon feeding SSF crude or FeSO(4) to rats. In contrast, Hb concentration was recovered to less extent when SSF crude plus PAs was used instead of SSF crude alone (P < 0.05). A similar profile was observed with these three sample groups when serum iron and RBC were used as parameters. All rats in PAs group died at the 8th week. Taken together, all these results demonstrated that PAs inhibited iron uptake of rats from SSF, and are toxic for rats with IDA.

Differential Gene Expression and Biological Analyses of Primary Hepatocytes Following D-Chiro-Inositol Supplement.

Dietary supplements have improved the prevention of insulin resistance and metabolic diseases, which became a research hotspot in food science and nutrition. Obesity and insulin resistance, caused by a high-fat diet, eventually result in severe metabolic diseases, can be prevented with the dietary supplement D-chiro-inositol (DCI). In this work, we isolated mice primary hepatocytes with palmitic acid stimulation and DCI was applied to compare and contrast its effects of in primary hepatocyte biology. Before and after intervention with DCI, we used RNA-Seq technology to establish a primary hepatocyte transcriptome gene profile. We found that both PA and DCI cause a wide variation in gene expression. Particularly, we found that DCI plays critical role in this model by acting on glycolysis and gluconeogenesis. Overall, we generated extensive transcripts from primary hepatocytes and uncovered new functions and gene targets for DCI.

[Effects of exercise on spatial learning and hippocampal synaptic plasticity in brain aging mice].

OBJECTIVE: To examine the effects and mechanism of exercise on resisting brain aging from the aspect of synaptic plasticity. METHODS: Forty male ICR mice were randomly divided into 4 groups: the D-galactose-induced brain aging, brain aging plus exercise, exercise only and normal controls. Mice were subjected to treadmill running at intensity (25 m/min for 20 min daily, 6 days a week) level of exercise and were given 100 mg x kg(-1) x d(-1) subcutaneous injection of D-galactose to prepare brain aging model for 9 weeks. The Morris water maze (MWM) test was employed to determine their spatial learning and memory ability. Flow cytometry (FCM) was used to analyze the amount of hippocampal synaptosomes. Membrane fluidity of synaptosomes was measured by fluorescence polarization technique. Acetylcholinesterase (AChE) activity in brain was determined by hydroxylamine colorimetric assay. RESULTS: (1) In Morris water maze test, brain aging mice showed a significant longer escape latency (EL) than the normal control mice (P < 0.05). Brain aging mice plus exercise exhibited a significant shorter EL than brain aging mice (P < 0.05), but no difference was found when compared with normal control mice (P > 0.05). There were no statistical difference in EL between the controls and exercise group (P > 0.05). (2) The number of synaptosomes in brain aging mice and brain aging mice plus exercise were less than those in non-brain aging mice (the exercise and the control mice) (P < 0.05). The number of synaptosomes in brain aging mice plus exercise was more than brain aging mice (P < 0.05). There were no statistical difference in the number of synaptosomes between the controls and exercise group (P > 0.05). (3) Membrane fluidity of synaptosomes: the viscosity of membrane in brain aging group was higher than in non-brain aging group, and higher than brain aging plus exercise group (P < 0.05). There were no statistical difference in viscosity of membrane between brain aging group and non-brain aging group, and between the controls and exercise group (P > 0.05). (4) The AChE activity in brain aging and brain aging plus exercise group were higher than those in control and exercise group (P < 0.05). There were no statistical difference in AChE activity between the controls and exercise group (P > 0.05). CONCLUSION: Exercise can effectively protect against decline in the capacity of learning and memory in brain aging mice.

Alleviation Effect of Grape Seed Proanthocyanidins on Neuronal Apoptosis in Rats with Iron Overload.

We aimed to evaluate the effect of grape seed proanthocyanidins (GSPCs) on neuronal apoptosis, particularly through their roles in maintaining divalent mineral element balance and resisting oxidation in rats with iron overload. A total of 40 Sprague-Dawley rats were randomly divided into control, iron overload, GSPCs, and iron overload + GSPCs groups. The iron, calcium, zinc, magnesium, and copper contents in the brain tissue of the rats were measured using inductively coupled plasma mass spectrometry. Their oxidative stress state was determined using the relevant kit. The number of apoptotic neurons was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and synaptosome numbers were determined using the immunohistochemical approach. Fas, Bax, and Bcl-2 gene expressions in the cortex and hippocampus were detected using quantitative real-time polymerase chain reaction. After 7 weeks, compared with the control group, the zinc and magnesium contents; superoxide dismutase, glutathione peroxidase, and catalase activities; and synaptophysin and Bcl-2 gene expressions in the iron overload group were significantly decreased, whereas the iron, calcium contents, and malondialdehyde contents; TUNEL-positive cell numbers; and Fas and Bax gene expressions were significantly increased. There were no significant changes in the copper content. Conversely, the rats exhibited better recovery when GSPCs were used instead of iron alone. In summary, GSPCs protected against iron overload induced neuronal apoptosis in rats by maintaining the divalent mineral element balance, reducing oxidative stress, and regulating apoptotic genes expressions.

Protective effects of grape seed proanthocyanidins against iron overload-induced renal oxidative damage in rats.

BACKGROUND: Excessive exposure to iron can cause kidney damage, and chelating drugs such as deferoxamine and deferiprone have limited usefulness in treating iron poisoning. This study was designed to investigate the protective effects of grape seed proanthocyanidins (GSPAs) against iron overload induced nephrotoxicity in rats. The roles of GSPAs in chelating iron, antioxidant activity, renal function, pathological section, and apoptosis-related gene expression were assessed. METHODS: Newly weaned male Sprague-Dawley rats aged 21 days (weight, 65 ±â€¯5 g) were randomly divided into four groups containing 10 rats each: normal control (negative) group, iron overload (positive) group, GSPAs group, and GSPAs + iron overload (test) group. Iron dextran injections (2.5 mg⋅ kg-1) and GSPAs (25 mg⋅ kg-1) were intraperitoneally and intragastrically administered to rats daily for 7 weeks, respectively. Measurements included red blood cell (RBC) count and hemoglobin (Hb) level, serum total iron-binding capacity (TIBC), renal iron content, glutathione peroxidase (GSH-Px) activity, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, total antioxidant activity (T-AOC), creatinine (CR) and blood urea nitrogen (BUN) levels, pathological changes, and apoptotic Fas, Bax expressions in the kidney tissue. Differences among the dietary groups were determined using one-way analysis of variance with post-hoc Tukey's test. P < 0.05 was considered statistically significant. RESULTS: RBC count, Hb level, renal iron content, MDA content, CR and BUN levels, and Fas, Bax expressions significantly increased in the positive group than in the negative group; contrarily, TIBC, GSH-Px activity, and T-AOC significantly decreased in the positive group than in the negative group (P < 0.05). Although not statistically significant, SOD activity was slightly reduced in the positive group than in the negative group. Inflammatory cell infiltration and fibrous tissue proliferation were observed in the kidney tissue of the rats in the positive group; in contrast, the rats exhibited better recovery when GSPAs were used instead of iron alone. Compared with the positive group, RBC counts, Hb levels, renal iron contents, the MDA content, CR and BUN levels, and Fas, Bax expressions significantly decreased, whereas the TIBC, the GSH-Px and SOD activities as well as T-AOC significantly increased in the test group rats (P < 0.05). There were no significant differences in the RBC counts, Hb levels, TIBC, renal iron contents, the SOD activity and MDA content, CR and BUN levels, and Fas expression between the GSPAs and negative groups. The GSH-Px activity and T-AOC were significantly increased whereas Bax expression was significantly decreased in the GSPAs group rats than in the negative group rats (P < 0.05). The rats in the GSPAs, test, and negative groups displayed glomeruli and tubules with a clear structure; further, the epithelial cells in the renal tubules were neatly arranged. CONCLUSIONS: GSPAs have protective effects on nephrotoxicity in rats with iron overload. Thus, further investigation of GSPAs as a new and natural phytochemo-preventive agent against iron overload is warranted.

Effects of lead exposure on brain glucose metabolism and insulin signaling pathway in the hippocampus of rats.

The aim of this study was to determine whether Pb affects glucose metabolism in the hippocampus of rats. Male Sprague-Dawley rats aged 21 days were orally administered a 0.1%, 0.2%, or 0.3% lead acetate solution in deionized water for 65 days. Then, the weight of the rats; brain Pb content; brain glucose levels; activities of hexokinase, fructose-6-phosphate kinase, pyruvate kinase, glucose-6-phosphate dehydrogenase; expression of genes related to the insulin signaling pathway; as well as the gene and protein expression of glucose transporter (GLUT)-1 and GLUT-3 in the hippocampus were evaluated. The results showed that Pb content in the brain tissue of rats in the dose groups significantly increased, whereas the body weight gain, activities of glucose metabolism-related enzymes, and expression of the insulin signaling pathway-related genes significantly decreased compared to the corresponding values in the control group. In comparison with the control group, the brain glucose levels increased significantly in the low-dose group, but there were no significant differences with the middle- and high-dose groups. Furthermore, the mRNA of GLUT-1 in the three dose groups and the GLUT-3 in the middle- and high-dose groups rose markedly, while the GLUT-1 and GLUT-3 protein expression significantly increased in the middle- and high-dose groups and in the high-dose group, respectively. Taken together, the results showed that Pb exposure resulted in a lower body weight gain, higher brain Pb content and also affected brain glucose metabolism and the insulin signaling pathway.