Thiobarbituric acid value on fresh homogenate of rat as a parameter of lipid peroxidation in aging, CCl4 intoxication, and vitamin E deficiency

Structural and Morphological Changes in the Liver Due to Intestinal Endotoxins

BACKGROUND

Under normal physiological conditions, endotoxin (ET) released during self-renewal of the colibacillus pool is an obligate stimulus for the formation of the immune system and homeostasis of the body. Violation of the barrier function of the intestinal wall and the mechanisms of neutralization of endotoxin lead to systemic endotoxemia of intestinal origin. Its development is facilitated by stress, intoxication, a decrease in nonspecific resistance of the body, as well as damage to the intestinal mucosa and dysbiosis, where the mucous membrane is more vulnerable and permeable to endotoxin.

PURPOSE OF THE RESEARCH

The aim of this study is to compare and assess the severity and nature of hepatocyte damage from endotoxin exposure and the degree of manifestation of stress due to oxidation, to determine the characteristics of structural changes in hepatocytes and to assess the oxidation stress during endotoxin intoxication in the experiment with biochemical markers.

MATERIALS AND METHODS

The experiments were conducted on 40 non-linear rats, divided into two groups of 20 animals. Group 1 animals received intraperitoneal injections of ET of Escherichia coli drug (Sigma USA K-235) for seven days at a rate of 0.1 mg/kg of the body weight. Animals of the second group served as the control group. Character and stage of liver damage were studied using morphological methods, including electron and light microscopy. In studying oxidizing stress, biochemical methods were used to define the changes, such as conjugated dienes and dienketones, spontaneous oxidizing modification of proteins.

RESULTS AND CONCLUSION

1. The severity and depth of morphological changes in the liver during endotoxin intoxication were correlated with the dynamics of the content of lipid oxidation products (CD and DK, MDA) and proteins. There was a tendency for a more significant increase in the oxidative modification of proteins in serum. This confirms the data on the primary damage of proteins by free radicals. 2. When exposed to intestinal microflora endotoxin, pronounced dyscirculatory changes, fatty and hydropic degeneration of hepatocytes with signs of toxic damage to their nuclei were determined, but at the same time, the increased hyperplastic activity of sinusoidal cells remained associated with the effects of endotoxin. These changes are associated with both the direct toxic effect of endotoxin, and the effects of oxidative stress, in which endotoxin is a potent inducer.

Detrimental effects of 6 months exposure to very low doses of a mixture of six pesticides associated with chronic vitamin deficiency on rats

This study aimed to evaluate the long-term low-dose effects of exposure to a mixture of 6 pesticide active substances (diquat, imazamox, imazethapyr, tepraloxydin, bentazone, acifluorfen) and to elucidate if chronic vitamin deficiency can influence their toxicity. Two hundred Wistar rats were divided in 4 groups: a vitamin-sufficiency control group, a vitamin-deficiency control group, a vitamin sufficiency test group and a vitamin-deficiency test group. The test groups were treated with the aforementioned pesticides at doses 100 times lower than the corresponding NOAEL. After 6 months, ten rats from each group were sacrificed and a complete evaluation of blood and urine biochemistry, biomarkers of oxidative stress, xenobiotic detoxification enzymes and lysosomal enzymes and organ histopathology was performed. The pesticides mixture and vitamin deficiency determined an increase in alkaline phosphatase levels and urinary calcium levels, abnormal serum lipid profile, and a decrease of total blood proteins levels, red blood cells, haematocrit and haemoglobin. The combination of the two stressors up-regulated CYP1A1, CYP1A2, CYP2B1 and GST levels. This study provides a new proof for the need to move forward from single chemical testing to a more complex approach to account for the multitude of stressors that can challenge the setting of real safety levels.

Tanacetum vulgare L. (Tansy) as an effective bioresource with promising pharmacological effects from natural arsenal

The Tanacetum genus is a big treasure with the presence of biologically-active compounds and members of this genus are widely used for the treatment of several diseases in traditional medicine system. Considering this fact, we aimed to analyze the extracts from Tanacetum vulgare L. in case of chemical profiles and biological effects. Chemical characterization was performed by using UHPLC-HRMS technique and showed the presence of several phytochemical groups (107 compounds were identified, including phenolic acids, flavonoids, terpenoids and fatty acids. Biological abilities were examined by using antioxidant (DPPH, ABTS, FRAP, CUPRAC, metal chelating and phosphomolybdenum assays) and enzyme inhibition (tyrosinase, amylase, glucosidase and cholinesterase) properties. Pharmaco-toxicological investigations were also performed with the aim to identify limits of biocompatibility, anti-oxidant and neuromodulatory effects, in hypothalamic HypoE22 cells. A bioinformatic analysis was also carried to unravel the putative protein-targets for the observed biological effects. Generally, the tested hexane and hydroalcoholic extracts displayed stronger activities in antioxidant and enzyme inhibitory assays, when compared with water. In addition, multivariate analysis was performed to understand the differences in both solvents and plant parts and we clearly observed the separation of these parameters. The extracts (10 μg/mL) also stimulated DAT and inhibited TNFα and BDNF gene expression, in HypoE22 cells. In parallel, the extracts were also able to stimulate norepinephrine release from this cell line. By contrast, in the concentration range 50-100 μg/mL, the extracts reduced the HypoE22 viability, thus demonstrating cytotoxicity at concentrations 5-10 fold higher compared to those effective as neuromodulatory. Our observations manifested that T. vulgare has several beneficial effects and it can be used as a potential natural raw material for designing further health-promoting applications in nutraceutical, cosmeceutical, and pharmaceutical areas.

Evaluation of the Antioxidant Potency of Seseli L. Species (Apiaceae)

OBJECTIVES

In the present study, the antioxidant potency of ethyl acetate (AcOEt) and methanol (MeOH) extracts from the aerial parts of Seseli L. species was investigated for the first time.

MATERIALS AND METHODS

Seseli species L. such as Seseli andronakii Woronow ex Schischk., S. campestre Besser, S. corymbosum Boiss. & Heldr., S. gummiferum subsp. gummiferum Pall. ex Sm., S. hartvigii Parolly & Nordt, S. libanotis (L.) W.Koch, S. petraeum M.Bieb., S. peucedanoides (M.Bieb.) Koso-Pol., S. resinosum Freyn & Sint., and S. tortuosum L. growing in Turkey were collected and evaluated for their antioxidant capacity by using 1.1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation (LPO) inhibition methods.

RESULTS

The highest activities as a scavenger of DPPH radicals were found in the AcOEt extracts of S. peucedanoides (M.Bieb.) Koso-Pol (IC50=0.49 mg/mL), and S. libanotis (IC50=0.75 mg/mL); α-tocopherol was used as a positive control. On the other hand, in the LPO assay, the highest activities were determined in AcOEt and MeOH extracts (at 5 mg/mL) of S. tortuosum and S. libanotis (84-94%).

CONCLUSION

This report gives important information about the antioxidant capacity of Seseli L. species. This research on antioxidant capacity proves that the use of some species used in Eastern Anatolia (in salads) is correct. With this screening study performed in Seseli L. species growing in Turkey, in the future, it is planned to isolate antioxidant compounds from the most active strains of Seseli L.

Progressive Loss of Corneal Nerve Fibers and Sensitivity in Rats Modeling Obesity and Type 2 Diabetes Is Reversible with Omega-3 Fatty Acid Intervention: Supporting Cornea Analyses as a Marker for Peripheral Neuropathy and Treatment

PURPOSE

To determine whether cornea nerve fiber density and/or corneal function are valid markers for early detection and treatment of peripheral neuropathy in rats modeling prediabetes and type 2 diabetes.

METHODS

High-fat feeding combined without or with low-dose streptozotocin was used to create rat models for prediabetes and type 2 diabetes that were longitudinally studied for loss of structure and function of sensory nerves in the cornea and skin as well as nerve conduction velocity and vascular reactivity of epineurial arterioles. There were three time points examined in each of the three conditions with 12 rats per group. The latest time point (24 weeks of high-fat diet with or without 16 weeks of hyperglycemia) was used to examine reversibility of neuro and vascular pathology following 16 weeks of treatment with menhaden oil, a natural source of long-chain omega-3 polyunsaturated fatty acids. The number of rats in the intervention study ranged from 6 to 17.

RESULTS

Our longitudinal study demonstrated that vascular and neural dysfunction associated with obesity or type 2 diabetes occur early and are progressive. Decrease in cornea nerve fiber length and function were valid markers of disease in both the pre-diabetic and diabetic rat models and were more sensitive than decrease in intraepidermal nerve fiber density of the skin and thermal nociception of the hindpaw. Late intervention with menhaden oil significantly reversed both vascular and peripheral nerve damage induced by chronic obesity or type 2 diabetes.

CONCLUSION

These studies provide support for examination of corneal structure and function as an early marker of peripheral neuropathy in prediabetes and type 2 diabetes. Furthermore, we demonstrate that omega-3 polyunsaturated fatty acids derived from fish oil are an effective treatment for peripheral neuropathy that occurs with chronic obesity or type 2 diabetes.

Role of glutathione redox system on the susceptibility to deoxynivalenol of pheasant (Phasianus colchicus)

There are only a few reports on the effects of mycotoxins on pheasant (Phasianus colchicus) and the susceptibility to deoxynivalenol of these birds have never been reported before. The present experiment focuses to investigate the effects of different dietary concentrations of deoxynivalenol on blood plasma protein content, some parameters of lipid peroxidation and glutathione redox system and on the performance of pheasant chicks. A total of 320 1-day-old female pheasants were randomly assigned to four treatment groups fed with a diet contaminated with deoxynivalenol (control, 5.11 mg/kg, 11.68 mg/kg and 16.89 mg/kg). Birds were sacrificed at early (12, 24 and 72 h) and late (1, 2 and 3 weeks) stages of the experiment to demonstrate the oxidative stress-inducing effect of deoxynivalenol. Feed refusal was dose dependent, especially in the last third of the trial, but only minor body weight gain decrease was found. Lipid-peroxidation parameters did not show dose-dependent effect, except in blood plasma during the early stage of the trial. The glutathione redox system, reduced glutathione content and glutathione peroxidase activity, was activated in the liver, but primarily in the blood plasma. Glutathione peroxidase activity has changed parallel with reduced glutathione concentration in all tissues. Comparing our results with literature data, pheasants seem to have the same or higher tolerance to deoxynivalenol than other avian species, and glutathione redox system might contribute in some extent to this tolerance, as effective antioxidant defence against oxidative stress.

Protective effects induced by alcoholic Phlomis fruticosa and Phlomis herba-venti extracts in isolated rat colon: Focus on antioxidant, anti-inflammatory, and antimicrobial activities in vitro

Phlomis fruticosa L. and P. herba-venti are species belonging to the Lamiaceae family, which have been traditionally used to prepare tonic and digestive drinks. Multiple studies also demonstrated the inhibitory effects of P. fruticosa extracts and essential oil against oxidative/proinflammatory pathways and bacterial strains deeply involved in ulcerative colitis. Considering these findings, the present study evaluated the effects of alcoholic P. fruticosa and P. herba-venti leaf extracts in isolated rat colon challenged with Escherichia coli lipopolysaccharide (LPS), an ex vivo experimental paradigm of ulcerative colitis. In this context, we assayed colon levels of pro-oxidant and proinflammatory biomarkers, including nitrites, malondialdehyde (MDA), lactate dehydrogenase (LDH), and serotonin (5-HT). Additionally, the extracts have been tested in order to evaluate possible inhibitory effects on specific bacterial and fungal strains involved in ulcerative colitis. Alcoholic P. fruticosa and P. herba-venti extracts were able to blunt LPS-induced nitrite, MDA, 5-HT, and LDH levels in isolated rat colon. The same extracts also inhibited the growth of Pseudomonas aeruginosa, E. coli, Staphylococcus aureus, Candida albicans and Candida tropicalis. In conclusion, our findings show a potential role exerted by alcoholic P. fruticosa and P. herba-venti in managing the clinical symptoms related to ulcerative colitis.

Multidirectional biological investigation and phytochemical profile of Rubus sanctus and Rubus ibericus

In the present study, the biological properties, including, the enzyme inhibitory and antioxidant activities, as well as, the phytochemical profile of the ethyl acetate, methanol, and water extracts of Rubus sanctus Schreb. and Rubus ibericus Juz. leaves were determined using in vitro bioassays. Wide range of phytochemicals, including, hydroxybenzoic acids, hydroxycinnamic acids, acylquinic acids, ellagitannins, flavonoids, and triterpenoid saponins were determined using UHPLC-ESI/HRMS technique. The ethyl acetate and methanol extracts of the studied Rubus species effectively inhibited acetyl and butyryl cholinesterase. On the other hand, R. sanctus water extract showed low inhibition against α-amylase and prominent inhibitory action against α-glucosidase. Data collected from this study reported the radical scavenging and reducing potential of the studied Rubus species. Investigation of the protective effects of the different extracts of R. sanctus and R. ibericus in experimental model of ulcerative colitis was performed. The extracts were also tested on spontaneous migration of human colon cancer cells (HCT116) in wound healing experimental paradigm. Only R. sanctus methanol extract inhibited spontaneous HCT116 migration in the wound healing test. Our results suggested that R. sanctus and R. ibericus may be potential candidates as sources of biologically-active compounds for the development of nutraceuticals, pharmaceuticals, and/or cosmetics.

Multiple pharmacognostic characterization on hemp commercial cultivars: Focus on inflorescence water extract activity

One of the most promising economic perspectives of hemp production chain is female inflorescence valorization, despite there being actually no chemical composition or biological data from water fraction. In this context, the focus of this study is the evaluation of protective effects related to hemp water flower extracts from four commercial cultivars (Futura 75, Kc virtus, Carmagnola Cs and Villanova). We evaluated the phytochemical profile through validated spectrophotometric and HPLC methods. Then, we studied the biological activity on C2C12 and HCT116 cell lines, and in an ex vivo experimental model of ulcerative colitis, constituted by isolated LPS-stimulated colon. Particularly, we assayed the blunting effects induced by hemp water extract treatment on LPS-induced levels of nitrites, malondialdehyde (MDA), prostaglandin (PG)E₂ and serotonin (5-HT). All tested cultivars displayed similar total phenolic and flavonoid profile. However, Futura 75 water extract displayed a better antioxidant and anti-inflammatory profile. Considering this, Futura 75 extract activity has been subsequently assayed on bacterial and fungal species involved in ulcerative colitis, finding a significant inhibition on C. albicans and selected Gram positive and negative bacterial strains. Concluding, our results support the potential efficacy of hemp inflorescence water extracts in managing the clinical symptoms related to ulcerative colitis.

Multi-trichothecene mycotoxin exposure activates glutathione-redox system in broiler chicken

Co-occurrence of mycotoxin contamination of feeds is a frequent problem, therefore the purpose of this study was to evaluate the combined effect of T-2 toxin and deoxynivalenol (DON) on lipid peroxidation, parameters and regulation of the glutathione redox system in broiler chickens in a sub-chronic (7 day) study. The applied doses were: low mix: 0.23 mg T-2 toxin and 4.96 mg DON/kg feed; medium mix: 1.21 mg T-2 toxin and 12.38 mg DON/kg feed; and high mix: 2.42 T-2 toxin and 24.86 mg DON/kg feed. Liver samples were taken on days 0, 1, 2, 3, and 7 of the feeding trial. Lipid peroxidation decreased significantly as compared to the control on days 3 and 7 as effect of low and high doses, which can be related to the activation of the antioxidant system, which is supported by the elevated glutathione peroxidase activity and reduced glutathione concentration as compared to the control on day 3 in the medium and high dose groups. Gene expression of glutathione peroxidase 4 (GPX4) elevated on day 1 in a dose dependent manner, and showed continuous elevation in the highest dose group thereafter. The results suggested that common exposure of T-2 toxin and DON induced oxidative stress in the liver of broiler chickens, which activated the enzymatic antioxidant system, and consequently decreased lipid peroxidation.

Role of Glutathione Redox System on the T-2 Toxin Tolerance of Pheasant (Phasianus colchicus)

The purpose of the present study was to evaluate the effects of different dietary concentrations of T-2 toxin on blood plasma protein content, lipid peroxidation and glutathione redox system of pheasant (Phasianus colchicus). A total of 320 one-day-old female pheasants were randomly assigned to four treatment groups fed with a diet contaminated with different concentrations of T-2 toxin (control, 4 mg/kg, 8 mg/kg and 16 mg/kg). Birds were sacrificed at early (12, 24 and 72 hr) and late (1, 2 and 3 weeks) stages of the experiment to demonstrate the effect of T-2 toxin on lipid peroxidation and glutathione redox status in different tissues. Feed refusal and impaired growth were observed with dose dependent manner. Lipid-peroxidation was not induced in the liver, while the glutathione redox system was activated partly in the liver, but primarily in the blood plasma. Glutathione peroxidase activity has changed parallel with reduced glutathione concentration in all tissues. Based on our results, pheasants seem to have higher tolerance to T-2 toxin than other avian species, and glutathione redox system might contribute in some extent to this higher tolerance, in particular against free-radical mediated oxidative damage of tissues, such as liver.

Evaluation of KIM-1 as an early biomarker of snakebite-induced AKI in mice

Acute kidney injury (AKI) is one of the most important complications of bothropic poisoning and its early identification remains challenging. The nephrotoxicity of Bothrops insularis venom (BinsV) was previously described by our research group. In this study, we continued to evaluate the effect of BinsV on kidney function in mice and LLC-MK2 proximal tubule cells, evaluating KIM-1 protein as an early AKI biomarker. Male Swiss mice were inoculated with BinsV intramuscularly and observed for 24 h in a metabolic cage model. Urine and blood were collected for biochemical analyses and the kidneys were examined for oxide-reducing balance and submitted to histological analysis. LLC-MK2 cells incubated with BinsV were assessed for cell viability and cell death mechanism by flow cytometry. Histological analysis of the kidneys indicated AKI and the oxide-reducing analyses demonstrated a decreasing in reduced glutathione (GSH) levels and an increasing on Malondialdehyde (MDA) levels. BinsV was cytotoxic to LLC-MK2 and the cytometry analyses suggested necrosis. Within 24 h after the envenomation, urinary creatinine did not increase, but the urinary levels of KIM-1 increased. In conclusion, we found AKI evidence in the kidney tissue and the increase in the KIM-1 levels suggest it can be used as an early AKI biomarker.

Graminex Pollen: Phenolic Pattern, Colorimetric Analysis and Protective Effects in Immortalized Prostate Cells (PC3) and Rat Prostate Challenged with LPS

Prostatitis, a general term describing prostate inflammation, is a common disease that could be sustained by bacterial or non-bacterial infectious agents. The efficacy of herbal extracts with antioxidant and anti-inflammatory effects for blunting the burden of inflammation and oxidative stress, with possible improvements in clinical symptoms, is under investigation. Pollen extracts have been previously reported as promising agents in managing clinical symptoms related to prostatitis. The aim of the present work was to evaluate the protective effects of Graminex pollen (Graminex^TM, Deshler, OH, USA), a commercially available product based on standardized pollen extracts, in rat prostate specimens, ex vivo. In this context, we studied the putative mechanism of action of pollen on multiple inflammatory pathways, including the reduction of prostaglandin E₂ (PGE₂), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and malondialdehyde (MDA), whose activities were significantly increased by inflammatory stimuli. We characterized by means of chromatographic and colorimetric studies the composition of Graminex pollen to better correlate the activity of pollen on immortalized prostate cells (PC3), and in rat prostate specimens challenged with Escherichia coli lipopolysaccharide (LPS). We found that Graminex pollen was able to reduce radical oxygen species (ROS) production by PC3 cells and MDA, NFκB mRNA, and PGE₂ levels, in rat prostate specimens. According to our experimental evidence, Graminex pollen appears to be a promising natural product for the management of the inflammatory components in the prostate.

Crocus sativus L. stigmas and byproducts: Qualitative fingerprint, antioxidant potentials and enzyme inhibitory activities

Saffron (Crocus sativus L.) has been previously reported to be active as a protective agent in multiple experimental models of oxidative stress, inflammation and cancer. These findings refer to the protective effects of stigmas, not byproducts such as tepals and anthers. In this context, the aims of the present work were to characterize the phytochemical profile of saffron stigmas (CST) and high quality byproducts (tepals + anthers - CTA) extracts. Additionally, we studied the antioxidant and chelating effects of CST and CTA extracts by preliminary in vitro assay. The antioxidant activity was further investigated through the evaluation of reactive oxygen species (ROS) levels and lactate dehydrogenase (LDH) activity on mouse myoblast (C2C12) and human colon cancer (HCT116) cell lines. Additionally, we evaluated CST and CTA extract treatment on cholinesterases, α-glucosidase and α-amylase activity, in vitro. Finally, we studied the effects of CST extract on malondialdehyde (MDA) level in rat colon specimens challenged with E. coli lipopolysaccharide (LPS). We observed that water CST extracts are rich in phenolic content, whereas for CTA the olive oil was the elective extraction solvent. As expected, water CST extracts were the most effective in reducing hydrogen peroxide-induced oxidative stress in both cell lines and in vitro assays. Furthermore, both CST and CTA water extracts reduced the LDH activity in HCT116 cells challenged with hydrogen peroxide and LPS-induced MDA levels in rat colon specimens. Concluding, the present findings showed protective effects exerted by CST and CTA extracts in in vitro and ex vivo models of inflammation and oxidative stress.

Changes in the regulation and activity of glutathione redox system, and lipid peroxidation processes in short-term aflatoxin B1 exposure in liver of laying hens

The purpose of this study was to investigate the short-term (48 hr) effects of feeding aflatoxin contaminated diet (170.3 μg/kg AFB1) in 49-week-old laying hens. Liver samples were taken at 12-hr intervals. Feed intake, body weight, absolute and relative liver weight were the same in groups. However, there was no feed intake during both dark periods (between 12nd to 24th and 36th to 48th hours of the experiment); therefore, aflatoxin intake was also negligible. Markers of initial phase of lipid peroxidation, conjugated dienes and trienes did not change as effect of aflatoxin, but terminal marker, malondialdehyde content was significantly higher at 12 hr as effect of aflatoxin. No significant difference was found in reduced glutathione concentration and glutathione peroxidase activity between the groups. Expression of glutathione peroxidase 4 gene (GPX4) was significantly reduced due to aflatoxin treatment at 12 and 24 hr, but induced later, while glutathione reductase gene (GSR) expression was significantly lower at 24 hr and glutathione synthetase gene (GSS) in aflatoxin-treated group at 12 hr. The results suggest that aflatoxin induced oxygen-free radical formation, but it did not reach critical level during this short period of time to cause activation of the expression of glutathione system.

The Effect of Hemodialysis and Acetate-Free Biofiltration on Anemia

The authors monitored, for a period of 12 months, anemia-, nutrition-, and free radical-related parameters and the rHuEPO dose required to maintain target hemoglobin (Hb) in 20 patients with chronic renal failure. Ten patients each were randomized for treatment by either acetate-free biofiltration (AFB) or low-flux hemodialysis (HD). At baseline, Hb levels were 102±2 (AFB) vs. 98±2 g/L (HD) (not significant difference, NS), the rHuEPO dose was 4050±976 vs. 5100±1538 IU/week (NS). Compared with baseline and with HD, lower rHuEPO doses were required during AFB at months 8, 9, 10 and 11, and 12 when they were 2100±510 (AFB) vs. 6000±1153 (HD), p=0.008. Prealbumin, transferrin and cholinesterase levels rose in the AFB group. Kt/V, albumin, transferrin saturation, aluminium, bicarbonate in serum, superoxide dismutase and glutathione peroxidase in erythrocytes, and malondialdehyde and antioxidant capacity in plasma did not differ between the AFB and HD groups. In terms of anemia control, AFB using an AN69 membrane was found to be more advantageous than low-flux HD, AFB improves some nutritional parameters. The compared methods do not differ in their effect on lipid peroxidation and the antioxidant system. (Int J Artif Organs 2000; 23: 173–80)

Impaired Corneal Sensation and Nerve Loss in a Type 2 Rat Model of Chronic Diabetes Is Reversible With Combination Therapy of Menhaden Oil, α-Lipoic Acid, and Enalapril

PURPOSE

This study investigated the efficacy of monotherapy versus combination of menhaden oil, α-lipoic acid, and enalapril on corneal sensation and morphometry and other neuropathy-related endpoints in a rat model of type 2 diabetes.

METHODS

Male Sprague-Dawley rats (aged 12 weeks) were fed a high-fat diet for 8 weeks followed by 30 mg/kg streptozotocin. After 16 weeks of hyperglycemia, 12-week treatments consisting of menhaden oil, α-lipoic acid, enalapril, or their combination were initiated. Before and after treatments, we performed analyses of multiple neural and vascular endpoints including corneal sensitivity, corneal nerve density, vascular reactivity of epineurial arterioles, motor and sensory nerve conduction velocity, intraepidermal nerve fiber density, and thermal nociception.

RESULTS

Before treatment, all the neural and vascular endpoints in diabetic rats were impaired. Treating diabetic rats with monotherapy was effective in improving neural and vascular deficits with menhaden oil being most efficacious. However, the combination therapy provided the greatest benefit and improved/reversed all nerve and vascular deficits. The effect of combination therapy on corneal relative sensitivity and structure (in mm/mm), primary endpoints for this study, for control, diabetic, and diabetic treated rats was 4.2 ± 1.4 and 7.5 ± 0.5, 12.1 ± 1.3* and 3.8 ± 0.2*, and 6.6 ± 2.3 and 7.3 ± 0.5, respectively (*P < 0.05 compared with control rats; P < 0.05 compared with diabetic rats).

CONCLUSIONS

These studies suggest that a combination therapeutic approach may be most effective for treating vascular and neural complications of type 2 diabetes.

Protective Effects Induced by Microwave-Assisted Aqueous Harpagophytum Extract on Rat Cortex Synaptosomes Challenged with Amyloid β-Peptide

Harpagophytum procumbens is a plant species that displays anti-inflammatory properties in multiple tissues. The iridoid glycosides arpagoside, harpagide, and procumbide appear to be the most therapeutically important constituents. In addition, harpagoside treatment exerted neuroprotective effects both in vitro and in vivo. Considering these findings, the aim of the present work is to explore the possible protective role of the previously described microwave-assisted aqueous extract of H. procumbens on rat hypothalamic (Hypo-E22) cells, and in rat cortex challenged with amyloid β-peptide (1-40). In this context, we assayed the protective effects induced by H. procumbens by measuring the levels of malondialdehyde, 3-hydroxykynurenine (3-HK), brain-derived neurotrophic factor, and tumor necrosis factor-α, 3-HK. Finally, we evaluated the effects of H. procumbens treatment on cortex levels of dopamine, norepinephrine, and serotonin. H. procumbens extract was well tolerated by Hypo-E22 cells and upregulated brain-derived neurotrophic factor gene expression but down-regulated tumor necrosis factor-α gene expression. In addition, the extract reduced amyloid β-peptide stimulation of malondialdehyde and 3-HK and blunted the decrease of dopamine, norepinephrine, and serotonin, in the cortex. In this context, our work supports further studies for the evaluation and confirmation of Harpagophytum in the management of the clinical symptoms related to Alzheimer's disease. Copyright © 2017 John Wiley & Sons, Ltd.

Nephroprotective effects of (-)-α-bisabolol against ischemic-reperfusion acute kidney injury

BACKGROUND

Ischemia/reperfusion (I/R) in kidney is commonly related to acute kidney injury (AKI), essentially through oxidative stress. (-)-α-Bisabolol is a sesquiterpene isolated from the essential oil of a variety of plants, including chamomile, which has important antioxidant activity.

STUDY DESIGN

This study intends to evaluate the nephroprotective activity of (-)-α-bisabolol (Bis) in both in vivo and in vitro models of kidney I/R.

METHODS

Male Wistar rats were submitted to right nephrectomy, followed by ischemia by clamping of the renal artery in the left kidney for 60min. and 48h of reperfusion. The animals were treated orally with Bis (100mg/kg) or vehicle for 24h after reperfusion, and placed in metabolic cages, to evaluate water consumption, diuresis, urinary osmolality, classic biochemical markers and urinary KIM-1 (kidney injury molecule-1). Additionally, the left kidney was collected for histological evaluation and determination of glutathione (GSH) and Thiobarbituric Acid Reactive Substances (TBARS) levels. Tubular epithelial cells LLC-MK2 were used to assess Bis effect on in vitro I/R, by MTT assay. It was performed the cellular respiration tests by flow cytometry: evaluation of the production of cytoplasmic reactive oxygen species by DCFH-DA assay and mitochondrial transmembrane potential analysis with the dye rhodamine 123.

RESULTS

I/R caused alterations in diuresis, water intake, urinary osmolality, plasmatic creatinine, urea and uric acid, creatinine clearance, proteinuria and microalbuminuria. Treatment with Bis ameliorated all of these parameters. Also, KIM-1 level enhanced by I/R was also diminished in groups treated with Bis. The histological examination showed that Bis attenuated the morphological changes caused by I/R, markedly vascular congestion and intratubular deposits of proteinaceous material. Additionally, Bis was able to reduce the changes observed in TBARS and GSH levels in kidney tissue. In in vitro assay, Bis was capable to partially protect the cell lineage against cell damage induced by I/R.

CONCLUSION

(-)-α-Bisabolol has a nephroprotective effect in kidney I/R, with antioxidant effect. Moreover, this result seems to be associated to a direct protective effect on tubular epithelia.

Therapeutic potential of Mesenchymal Stem Cells for the treatment of diabetic peripheral neuropathy

Type-1 Diabetes is generally treated with exogenous insulin administration. Despite treatment, a very common long term consequence of diabetes is the development of a disabling and painful peripheral neuropathy. The transplantation of pancreatic islets is an advanced alternative therapeutic approach, but its clinical application is still very limited, mainly because of the great number of islets required to complete the procedure and of their short-term survival. An intriguing method to improve the performance of pancreatic islets transplantation is the co-transplantation of Mesenchymal Stem Cells (MSCs), adult stem cells already known to support the survival of different cellular populations. In this proof-of-concept study, we demonstrated using an in vivo model of diabetes, the ability of allogenic MSCs to reduce the number of pancreatic islets necessary to achieve glycemic control in diabetic rats, and overall their positive effect on diabetic neuropathy, with the reduction of all the neuropathic signs showed after disease induction. The cutback of the pancreatic islet number required to control glycemia and the regression of the painful neuropathy make MSC co-transplantation a very promising tool to improve the clinical feasibility of pancreatic islet transplantation for diabetes treatment.

Synthesis and biological evaluation of various new bis-isoxazoline derivatives as potential antioxidant additives

1,4-Bis[4-(4-benzoyl-5-phenylisoxazol-3-yl)-3-methyl-1-phenylpyrazol-5-yloxy]benzene and its derivatives were synthesised. The antioxidant activities of these compounds were investigated in vitro assay systems, such as lipid peroxidation, 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azino-bis(3-ethyl-1,3-benzothiazoline-6-sulfonic acid), superoxide, hydroxyl radicals scavenging and reducing power assay. The results show that the target compounds with nitro- and chloro-substituents at the 4-position of the benzene ring had more effective antioxidant power and better radical scavenging activity (RSA) (%) values when compared to those of butylated hydroxytoluene, trolox, caffeic acid and ascorbic acid, respectively..

Short-term effects of T-2 toxin exposure on some lipid peroxide and glutathione redox parameters of broiler chickens

The purpose of this study was to investigate the short-term effects of T-2 toxin exposure (3.09 mg/kg feed) on lipid peroxidation and glutathione redox system of broiler chicken. A total of 54 Cobb 500 cockerels were randomly distributed to two experimental groups at 21 days of age. Samples (blood plasma, red blood cell, liver, kidney and spleen) were collected every 12 h during a 48-h period. The results showed that the initial phase of lipid peroxidation, as measured by conjugated dienes and trienes in the liver, was continuously, but not significantly higher in T-2 toxin-dosed birds than in control birds. The termination phase of lipid peroxidation, as measured by malondialdehyde, was significantly higher in liver and kidney as a result of T-2 toxin exposure at the end of the experimental period (48th hour). The glutathione redox system activated shortly after starting the T-2 toxin exposure, which is supported by the significantly higher concentration of reduced glutathione and glutathione peroxidase activity in blood plasma at 24 and 48 h, in liver at 12, 24 and 36 h, and in kidney and spleen at 24 h. These results suggest that T-2 toxin, or its metabolites, may be involved in the generation of reactive oxygen substances which causes an increase in lipid peroxidation, and consequently activates the glutathione redox system, namely synthesis of reduced glutathione and glutathione peroxidase.

Tropical soils with high aluminum concentrations cause oxidative stress in two tomato genotypes

Tropical and subtropical soils are usually acidic and have high concentrations of aluminum (Al). Aluminum toxicity in plants is caused by the high affinity of the Al cation for cell walls, membranes, and metabolites. In this study, the response of the antioxidant-enzymatic system to Al was examined in two tomato genotypes: Solanum lycopersicum var. esculentum (Calabash Rouge) and Solanum lycopersicum var. cerasiforme (CNPH 0082) grown in tropical soils with varying levels of Al. Plant growth; activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPOX), and glutathione reductase (GR) enzymes; stress-indicating compounds (malondialdehyde (MDA) and hydrogen peroxide); and morphology (root length and surface area) were analyzed. Increased levels of Al in soils were correlated with reduced shoot and root biomass and with reduced root length and surface area. Calabash Rouge exhibited low Al concentrations and increased growth in soils with the highest levels of Al. Plants grown in soils with high availability of Al exhibited higher levels of stress indicators (MDA and hydrogen peroxide) and higher enzyme activity (CAT, APX, GPOX, and GR). Calabash Rouge absorbed less Al from soils than CNPH 0082, which suggests that the genotype may possess mechanisms for Al tolerance.

Testicular effect of a mixture of 2-methoxyethanol and 2-ethoxyethanol in rats

BACKGROUND

2-Methoxyethanol (ME) and 2-ethoxyethanol (EE) represent a large group of chemicals which are used separately or as mixtures. These compounds exert multidirectional toxic effects. The present studies aimed to demonstrate the effects of ME and EE alone and their mixture on the reproductive organs in the rats.

METHODS

Male Wistar rats were treated subcutaneously with ME and EE alone (1.25-5.0mM/kg/day) or with their mixture (1:1) for 4 weeks. After completion of the experiment, the testes, epididymides, and prostate were weighed. In post-mitochondrial supernatant of the testes, the level of total protein, non-protein and protein sulfhydryl groups, malondialdehyde, total antioxidant status, and glutathione peroxidase and glutathione reductase activities were determined.

RESULTS

Exposure to ME alone resulted in a dose-dependent decrease in the organ weights, the total protein, non-protein and protein sulfhydryl groups. EE alone led to less marked alterations. Co-exposure to ME and EE caused alterations similar as in the rats treated with ME alone.

CONCLUSIONS

Marked testicular atrophy, decrease in epididymis and prostate weights are predominant effects of the repeated exposure to relatively low doses of ME and EE. A decrease in the total protein level, and protein sulfhydryl groups may be responsible for testicular atrophy. A significant depletion of non-protein sulfhydryl groups and occasionally elevated glutathione peroxidase activity may indicate that ME and EE resulted in disturbances of pro-oxidant/antioxidant balance. The study suggests that testicular toxicity in male rats co-exposed to ME and EE is mainly caused by the former compound.

Synthesis and antioxidant properties of substituted 2-phenyl-1H-indoles

In this study, we report the design, synthesis and antioxidant activity of a series of substituted 2-(4-aminophenyl)-1H-indoles and 2-(methoxyphenyl)-1H-indoles. The new compounds are structurally related to the known indole-based antioxidant lead compound melatonin (MLT), and the antitumour 2-(4-aminophenyl)benzothiazole and 2-(3,4-dimethoxyphenyl)benzothiazole series. Efficient access to the target 2-phenylindoles was achieved via Fischer indole synthesis between substituted phenylhydrazines and acetophenones. 2-(4-Aminophenyl)indoles (such as the 6-fluoro analogue 3b) in particular showed potent antioxidant activity in the DPPH and superoxide radical scavenging assays (80% and 81% inhibition at 1mM concentration of 3b, respectively), at a level comparable with the reference standard MLT (98% and 75% at 1 mM).

The effect of feeding a diet naturally contaminated with deoxynivalenol on production traits and selected biochemical indicators of broiler chickens

The effect of feeding a diet naturally contaminated with deoxynivalenol (DON) (0-21 days: 1.50 mg·kg-1; 22-39 days: 1.54 mg·kg-1) was studied in 40 broiler chickens. Birds were divided into two groups fed a control diet and a diet contaminated with DON (n = 20 in each). Feed intake was measured daily and individual live weight weekly; daily weight gain and feed to gain ratio were calculated. Five animals from each group were euthanized on days 21and 39 when blood (blood plasma and red blood cell haemolysates) and liver samples were collected. Concentration of triglyceride, uric acid and glucose and activities of ALT, AST and LDH were measured in blood plasma. Indicators of lipid peroxide and glutathione redox status, malondialdehyde and reduced glutathione concentration and glutathione-peroxidase activity were measured in blood plasma, red blood cell haemolysates and liver homogenates. The low dose of DON did not cause difference in the production traits, but caused significantly lower concentration of uric acid and glucose, and significantly higher concentration of triglyceride in blood plasma on day 21. Enzyme activities in blood plasma did not differ significantly between the treatment groups. Among the markers of lipid peroxide and glutathione redox status, malondialdehyde content was significantly higher in liver homogenate on day 21 in the group fed with DON contaminated diet, but reduced glutathione content and glutathione peroxidase activity did not differ significantly between the treatment groups. The results showed that diet contaminated even with a low content of deoxynivalenol caused alterations in selected biochemical indicators of blood and liver of broiler chicken.

Synthesis and comparison of antioxidant properties of indole-based melatonin analogue indole amino Acid derivatives

Increased levels of reactive oxygen species attributed to oxidative stress have been found to be responsible for the development of some vital diseases such as cardiovascular, neurodegenerative and autoimmune diseases. Recently, it was observed that melatonin is a highly important antioxidant, and melatonin analogues are under investigation to find out improved antioxidant activity. In this study, 14 melatonin -based analogue indole amino acid and N-protected amino acid derivatives were synthesized and elucidated spectrometrically. To investigate the antioxidant activity of the synthesized compounds and to compare with melatonin, butylhydroxytoluene and vitamin E, lipid peroxidation inhibition and 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activities were tested. The results indicated that the synthesized new indole amino acid derivatives have similar activities to melatonin in 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity assay but more potent activities in lipid peroxidation inhibition assay.

Determination of urinary malondialdehyde by isotope dilution LC-MS/MS with automated solid-phase extraction: a cautionary note on derivatization optimization

A highly sensitive quantitative LC-MS/MS method was developed for measuring urinary malondialdehyde (MDA). With the use of an isotope internal standard and online solid-phase extraction, urine samples can be directly analyzed within 10 min after 2,4-dinitrophenylhydrazine (DNPH) derivatization. The detection limit was estimated as 0.08 pmol. This method was further applied to assess the optimal addition of DNPH for derivatization and to measure urinary MDA in 80 coke oven emission (COE)-exposed and 67 nonexposed workers. Derivatization optimization revealed that to achieve complete derivatization reaction, an excess of DNPH is required (DNPH/MDA molar ratio: 893-8929) for urine samples that is about 100 times higher than that of MDA standard solutions (molar ratio: 10-80). Meanwhile, the mean urinary concentrations of MDA in COE-exposed workers were significantly higher than those in nonexposed workers (0.23±0.17 vs 0.14±0.05 μmol/mmol creatinine, P<0.005). Urinary MDA concentrations were also significantly associated with the COE (P<0.005) and smoking exposure (P<0.05). Taken together, this method is capable of routine high-throughput analysis and accurate quantification of MDA and would be useful for assessing the whole-body burden of oxidative stress. Our findings, however, raise the issue that derivatization optimization should be performed before it is put into routine biological analysis.

Influence of Cord Blood Fraction (below 5 kDa) on Reparative Processes during Subchronic Ulcerative Gastropathy

The low molecular fraction (below 5 kDa) was extracted from cord blood by ultrafiltration. It has been shown that the cord blood fraction possesses antiulcer activity on the model subchronic stomach ulcer. The cord blood fraction injections caused a significant reduction in the area of ulcer lesions and promoted recovery of microcirculation, thickness, and structure of gland layer, which was accompanied by a decrease in leucocytes infiltration and an increase in glycosaminoglycans synthesis. That resulted in a faster recovery of mucus membrane of stomach as compared with Actovegin. Application of the cord blood fraction in animals with stomach ulcer normalized the alkaline phosphatase activity and thiobarbituric acid-active product content. Gel-penetrating chromatography showed that the patterns of the low molecular substances from cord blood and Actovegin differed both qualitatively and quantitatively.

Diet-induced obesity in Sprague-Dawley rats causes microvascular and neural dysfunction

BACKGROUND

The objective of this study was to determine the effect of diet-induced obesity (DIO) on microvascular and neural function.

METHODS

Rats were fed a standard or high fat diet for up to 32 weeks. The following measurements were carried out: vasodilation in epineurial arterioles using videomicroscopy, endoneurial blood flow using hydrogen clearance, nerve conduction velocity using electrical stimulation, size-frequency distribution of myelinated fibres of the sciatic nerve, intraepidermal nerve fibre density using confocal microscopy and thermal nociception using the Hargreaves method.

RESULTS

Rats fed a high fat diet for 32 weeks developed sensory neuropathy, as indicated by slowing of sensory nerve conduction velocity and thermal hypoalgesia. Motor nerve conduction velocity and endoneurial blood flow were not impaired. Mean axonal diameter of myelinated fibres of the sciatic nerve was unchanged in high fat-fed rats compared with that in control. Intraepidermal nerve fibre density was significantly reduced in high fat-fed rats. Vascular relaxation to acetylcholine and calcitonin gene-related peptide was decreased and expression of neutral endopeptidase (NEP) increased in epineurial arterioles of rats fed a high fat diet. In contrast, insulin-mediated vascular relaxation was increased in epineurial arterioles. NEP activity was significantly increased in the skin of the hindpaw. Markers of oxidative stress were increased in the aorta and serum of high fat-fed rats but not in epineurial arterioles.

CONCLUSION

Chronic obesity causes microvascular and neural dysfunction. This is associated with increased expression of NEP but not oxidative stress in epineurial arterioles. NEP degrades vasoactive peptides, which may explain the decrease in microvascular function.

Effect of T-2 and HT-2 Toxin during the Growing Period on Body Weight, Lipid Peroxide and Glutathione Redox Status of Broiler Chickens

The effect of T-2 and HT-2 toxin using different doses in the starter (0-21 days: 1.04 mg T-2 toxin and 0.49 mg HT-2 toxin kg-1feed), and finisher diets (22-39 days: 0.12 mg T-2 toxin and 0.02 mg HT-2 toxin kg-1feed) was investigated in broiler chickens. Birds were divided into two groups fed with control and T-2 and HT-2 toxin contaminated diets. Pathological signs of toxicity were investigated on days 21 and 39 of the trial, individual liveweight was measured weekly. Five birds from each group were sacrificed on the 21st and 39th days of treatment, when blood plasma, red blood cell, liver and kidney samples were taken, in which malondialdehyde and reduced glutathione concentration and glutathione-peroxidase activity were determined. Pathological signs (lesions in the oral cavity and on the tongue, inflammation in the small intestine) were found in the group fed T-2 and HT-2 toxin contaminated feed on day 21 compared to control. Body weight was significantly lower as a result of feeding T-2 and HT-2 toxin contaminated diet. However, the contamination did not cause a significant increase of malondialdehyde content in the analysed tissues. Reduced glutathione content was significantly lower in the liver homogenate on day 39 than that of the control. Glutathione peroxidase activity also did not differ significantly in blood plasma, red blood cell haemolysates and kidney homogenates, while it was significantly higher in the liver homogenates of the mycotoxin-challenged birds. In conclusion, it can be stated that T-2 and HT-2 toxin exposure has long-term effects in broiler chickens.

Effect of combined treatment with aflatoxin B1 and T-2 toxin and metabolites on some production traits and lipid peroxide status parameters of broiler chickens

Three groups of cockerels were fed with a control diet, with a diet contaminated with T-2 and HT-2 toxin (0.31 and 0.26 mg/kg) or with that containing a combination of T-2 and HT-2 toxin (0.32 and 0.25 mg/kg) and aflatoxin B1 (AFB1, 0.38 mg/kg) for 21 days. Body weight gain and feed conversion ratio did not differ significantly among the groups. Malondialdehyde concentration of the liver was lower in the group fed the diet contaminated with the combination of T-2 + HT-2 toxin and aflatoxin B1 as compared to the control group or the group fed T-2 + HT-2 toxins. Reduced glutathione (GSH) content of the liver was lower in the T-2 + HT-2 group than in the group fed a combination of T-2, HT-2 and aflatoxin. Reduced glutathione content of the heart was higher in the T-2 + HT-2 group than in the control group. Mycotoxin contamination had no effect on glutathione peroxidase (GSH-Px) activity in comparison to the control, but significantly lower GSH-Px activity was found in the heart of chickens in the T-2 + HT-2 + AFB1 group than in the T-2 + HT-2 group. In this study, T-2 + HT-2 toxin and aflatoxin B1 contamination of the diets did not affect the production traits adversely and did not exert additive effects on lipid peroxidation and on the glutathione redox system.

NovelN-acyl dehydroalanine derivatives as antioxidants: Studies on rat liver lipid peroxidation levels and DPPH free radical scavenging activity

Oxidative stress has been implicated in the development of many neurodegenerative diseases such as Parkinson and Alzhemier's disease and is also responsible for aging, artherosclerosis, rheumatoid arthritis and carcinogenesis. Olefins such as dehydroalanines have been shown to inactivate free radicals by forming stabilized free radical adducts. Among these molecules N-acyl dehydroalanines react with and scavenge oxygen and hydroxyl radicals. This study describes the synthesis, characterization and in vitro effects on rat liver lipid peroxidation levels, and DPPH free radical scavenging activities of some N-acyl dehydroalanine derivatives. Compounds c, f and j slightly scavenged the level of DPPH radical at 10(-3) M concentration by about 27, 46, and 56%, respectively while compounds a, d, e, f, g, h showed a strong inhibitory effect on lipid peroxidation at 10(-3)M and 10(-4)M concentrations and inhibition was in the range of 76-90%. The possible antioxidant mechanism of the compounds was discussed.

Effect of dietary fatty acid pattern on growth, body fat composition and antioxidant parameters in broilers

The effects of dietary fat supplementation on performance, fatty acid (FA) composition of tissues and antioxidant defence system of broilers were studied. Male broilers were placed in 20 floor pens (60 broilers per pen). The broilers were fed by diets with added different energy sources: lard (L); sunflower oil (SFO); soybean oil (SBO); and linseed oil (LSO). The treatments did not modify significantly growth performance and feed intake of the broilers. There was no effect of dietary FA pattern on reduced glutathione level and glutathione peroxidase activity of plasma, erythrocyte and liver samples. However, higher PUFA content of the diet resulted in a significant increase in malondialdehyde level of erythrocytes and liver. The broilers fed LSO diet more effectively maintained their antioxidant status with enhanced plasma radical scavenger capacity. FA composition in tissues reflected the FA pattern of the diets, although proportion of FAs with four or more double bonds was metabolic specific. LSO diet increased the level of C18:3, C20:5 and C22:6 in tissue lipids in relation to L, SFO and SBO diets. Significantly increased plasma radical scavenging capacity in concert with the enhanced C20:5 and C22:6 proportion in liver and muscle during LSO feeding indicate metabolic changes to counteract the oxidative injury. This may be related to the compounds produced after different biochemical pathways of n-6 and n-3 FAs.