Effect of grape antioxidant dietary fiber on the total antioxidant capacity and the activity of liver antioxidant enzymes in rats

The potential role of mitochondrial impairment in the pathogenesis of imatinib-induced renal injury

Imatinib is a tyrosine kinase inhibitor widely administered against chronic myeloid leukemia. On the other hand, drug-induced kidney proximal tubular injury, electrolytes disturbances, and renal failure is a clinical complication associated with imatinib therapy. There is no precise cellular mechanism(s) for imatinib-induced renal injury. The current investigation aimed to evaluate the role of mitochondrial dysfunction and oxidative stress in the pathogenesis of imatinib nephrotoxicity. Rats received imatinib (50 and 100 mg/kg, oral, 14 consecutive days). Serum and urine biomarkers of renal injury and markers of oxidative stress in the kidney tissue were assessed. Moreover, kidney mitochondria were isolated, and mitochondrial indices, including mitochondrial depolarization, dehydrogenases activity, mitochondrial permeabilization, lipid peroxidation (LPO), mitochondrial glutathione levels, and ATP content were determined. A significant increase in serum (Creatinine; Cr and blood urea nitrogen; BUN) and urine (Glucose, protein, gamma-glutamyl transferase; γ-GT, and alkaline phosphatase; ALP) biomarkers of renal injury, as well as serum electrolytes disturbances (hypokalemia and hypophosphatemia), were evident in imatinib-treated animals. On the other hand, imatinib (100 mg/kg) caused an increase in kidney ROS and LPO. Renal tubular interstitial nephritis, tissue necrosis, and atrophy were evident as tissue histopathological changes in imatinib-treated rats. Mitochondrial parameters were also adversely affected by imatinib administration. These data represent mitochondrial impairment, renal tissue energy crisis, and oxidative stress as possible mechanisms involved in the pathogenesis of imatinib-induced renal injury and serum electrolytes disturbances.

Boldine Supplementation Regulates Mitochondrial Function and Oxidative Stress in a Rat Model of Hepatotoxicity

Background: The xenobiotics-induced liver injury is a clinical complication. Hence, finding new hepatoprotective strategies has clinical value. Oxidative stress and its subsequent complications are major mechanisms involved in xenobiotics-induced hepatotoxicity. Boldine is one of the most potent antioxidant molecules widely investigated for its protective properties in different experimental models. In the current study, the hepatoprotective properties of boldine and its potential mechanisms of hepatoprotection have been investigated. Methods: Rats received thioacetamide (TAA; 200 mg/kg, i.p) as a model of acute liver injury. Boldine (5, 10, 1nd 20 mg/kg; 24 hours intervals; oral) was administered as the hepatoprotective agent. Results: Liver injury was evident in TAA-treated animals (48 hours after TAA exposure) as a severe increase in serum level of liver injury biomarkers and histopathological alterations. Moreover, markers of oxidative stress were increased in liver tissue of TAA-treated rats. Assessment of mitochondrial indices of functionality revealed a significant decrease in mitochondrial dehydrogenases activity, the collapse of mitochondrial membrane potential, mitochondrial swelling and depletion of ATP content. It was found that boldine supplementation mitigated liver tissue markers of oxidative stress and improved mitochondrial indices of functionality in TAA-treated animals. Conclusion: The hepatoprotective properties of boldine might primarily rely on antioxidant and mitochondria protecting effects of this alkaloid.

The neuroprotective properties of carnosine in a mouse model of manganism is mediated via mitochondria regulating and antioxidative mechanisms

Objective(s): Manganese (Mn) is an essential trace element physiologically incorporated in the structure of several vital enzymes. Despite its essentiality, excessive Mn exposure is toxic with brain tissue as the primary target organ. There is no specific and clinically available therapeutic/preventive option against Mn neurotoxicity. Carnosine is a neuropeptide with several physiological roles. The neuroprotective properties of this peptide have been evaluated in different experimental models. The current study was designed to investigate the effect of carnosine supplementation and its potential mechanisms of action in an animal model of Mn-induced neurotoxicity. Materials and Methods: Male C57BL/6 mice received Mn (100 mg/kg, s.c) alone and/or in combination with carnosine (10, 50, and 100 mg/kg, i.p). Several locomotor activity indices were monitored. Moreover, biomarkers of oxidative stress and mitochondrial function were assessed in the brain tissue of Mn-exposed animals. Results: Significant locomotor dysfunction was revealed in Mn-exposed animals. Furthermore, brain tissue biomarkers of oxidative stress were significantly increased, and mitochondrial indices of functionality were impaired in Mn-treated animals. It was found that carnosine supplementation (10, 50, and 100 mg/kg, i.p) alleviated the Mn-induced locomotor deficit. Moreover, this peptide mitigated oxidative stress biomarkers and preserved brain tissue mitochondrial functionality in the animal model of manganism. Conclusion: These data indicate that carnosine is a potential neuroprotective agent against Mn neurotoxicity. Antioxidative and mitochondria protecting effects of carnosine might play a fundamental role in its neuroprotective properties against Mn toxicity.

Proline supplementation mitigates the early stage of liver injury in bile duct ligated rats

Background Proline is a proteinogenic amino acid with multiple biological functions. Several investigations have been supposed that cellular proline accumulation is a stress response mechanism. This amino acid acts as an osmoregulator, scavenges free radical species, boosts cellular antioxidant defense mechanisms, protects mitochondria, and promotes energy production. The current study was designed to investigate the effect of proline treatment on the liver in bile duct ligated (BDL) rats as an animal model of cholestasis/cirrhosis. Methods BDL rats were supplemented with proline-containing drinking water (0.25% and 0.5% w:v), and samples were collected at scheduled time intervals (3, 7, 14, 28, and 42 days after BDL surgery). Results Drastic elevation in the serum level of liver injury biomarkers and significant tissue histopathological changes were evident in BDL rats. Markers of oxidative stress were also higher in the liver of BDL animals. It was found that proline supplementation attenuated BDL-induced alteration in serum biomarkers of liver injury, mitigated liver histopathological changes, and alleviated markers of oxidative stress at the early stage of BDL operation (3, 7, and 14 days after BDL surgery). Conclusions The hepatoprotection provided by proline in BDL animals might be associated with its ability to attenuate oxidative stress and its consequences.

Mechanism of valproic acid-induced Fanconi syndrome involves mitochondrial dysfunction and oxidative stress in rat kidney

AIM

Drug-induced kidney proximal tubular injury and renal failure (Fanconi syndrome; FS) is a clinical complication. Valproic acid (VPA) is among the FS-inducing drugs. The current investigation was designed to evaluate the role of mitochondrial dysfunction and oxidative stress in VPA-induced renal injury.

METHODS

Animals received VPA (250 and 500 mg/kg, i.p., 15 consecutive days). Serum biomarkers of kidney injury and markers of oxidative stress were assessed. Moreover, kidney mitochondria were isolated and mitochondrial indices, including succinate dehydrogenase activity (SDA), mitochondrial depolarization, mitochondrial permeability transition pore (MPP), reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial glutathione, and ATP were determined.

RESULTS

Valproic acid-treated animals developed biochemical evidence of FS as judged by elevated serum gamma-glutamyl transferase (γ-GT), alkaline phosphatase (ALP), creatinine (Cr), and blood urea nitrogen (BUN) along with hypokalaemia, hypophosphataemia, and a decrease in serum uric acid. VPA caused an increase in kidney ROS and LPO. Renal GSH reservoirs were depleted and tissue antioxidant capacity decreased in VPA-treated animals. Renal tubular interstitial nephritis, tissue necrosis, and atrophy were also evident in VPA-treated rats. Mitochondrial parameters including SDA, MMP, GSH, ATP and MPP were decreased and mitochondrial ROS and LPO were increased with VPA treatment. It was found that carnitine (100 mg/kg, i.p.) mitigated VPA adverse effects towards the kidney.

CONCLUSIONS

These data suggest that mitochondrial dysfunction and oxidative stress contributed to the VPA-induced FS. On the other hand, carnitine could be considered a potentially safe and effective therapeutic option in attenuating VPA-induced renal injury.

Sulfasalazine induces mitochondrial dysfunction and renal injury

Sulfasalazine is a commonly used drug for the treatment of rheumatoid arthritis and inflammatory bowel disease. There are several cases of renal injury encompass sulfasalazine administration in humans. The mechanism of sulfasalazine adverse effects toward kidneys is obscure. Oxidative stress and its consequences seem to play a role in the sulfasalazine-induced renal injury. The current investigation was designed to investigate the effect of sulfasalazine on kidney mitochondria. Rats received sulfasalazine (400 and 600 mg/kg/day, oral) for 14 consecutive days. Afterward, kidney mitochondria were isolated and assessed. Sulfasalazine-induced renal injury was biochemically evident by the increase in serum blood urea nitrogen (BUN), gamma-glutamyl transferase (γ-GT), and creatinine (Cr). Histopathological presentations of the kidney in sulfasalazine-treated animals revealed by interstitial inflammation, tubular atrophy, and tissue necrosis. Markers of oxidative stress including an increase in reactive oxygen species (ROS) and lipid peroxidation (LPO), a defect in tissue antioxidant capacity, and glutathione (GSH) depletion were also detected in the kidney of sulfasalazine-treated groups. Decreased mitochondrial succinate dehydrogenase activity (SDA), mitochondrial depolarization, mitochondrial GSH depletion, increase in mitochondrial ROS, LPO, and mitochondrial swelling were also evident in sulfasalazine-treated groups. Current data suggested that oxidative stress and mitochondrial injury might be involved in the mechanism of sulfasalazine-induced renal injury.

Green leafy vegetables from two Solanum spp. (Solanum nigrum L and Solanum macrocarpon L) ameliorate scopolamine-induced cognitive and neurochemical impairments in rats

This study examined the modulatory effect of Black nightshade (Solanum nigrum L) and African eggplant (Solanum macrocarpon L) leaves on cognitive function, antioxidant status, and activities of critical enzymes of monoaminergic and cholinergic systems of neurotransmission in scopolamine-administered rats. Cognitive impairment was induced in albino rats pretreated with dietary inclusions of Black nightshade (BN) and African eggplant (AE) leaves by single administration (i.p.) of scopolamine (2 mg/kg body weight). Prior to termination of the experiment, the rats were subjected to spontaneous alternation (Y-maze) test to assess their spatial working memory. Thereafter, activities of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO), arginase, and antioxidant enzymes (catalase, SOD, and GST) of rat brain homogenate were determined. Also, the malondialdehyde (MDA), nitrite, and GSH contents of the homogenate were determined. The results showed that pretreatment with dietary inclusions of AE and BN significantly reversed the impairment in the rats' spatial working memory induced by scopolamine. Similarly, elevations in activities of AChE, BChE, and MAO induced by scopolamine were significantly reversed in rats pretreated with dietary inclusions of AE and BN. In addition, impaired antioxidant status induced by scopolamine was reversed by pretreatment with dietary inclusions of AE and BN. This study has shown that dietary inclusions of AE and BN could protect against cognitive and neurochemical impairments induced by scopolamine, and hence, these vegetables could be used as a source of functional foods and nutraceuticals for the prevention and management of cognitive impairments associated diseases such as Alzheimer's disease.

Preconditioning-Like Properties of Short-Term Hypothermia in Isolated Perfused Rat Liver (IPRL) System

Hypothermia may attenuate the progression of ischemia-induced damage in liver. Here, we determined the effects of a brief cycle of hypothermic preconditioning applied before an ischemic/reperfusion (I/R) episode in isolated perfused rat liver (IPRL) on tissue damage and oxidative stress. Rats (male, 200–250 g) were anaesthetised with sodium pentobarbital (60 mg·kg⁻¹ i.p) and underwent laparatomy. The liver was removed and perfused in a temperature-regulated non-recirculating system. Livers were randomly divided into two groups (n = 6 each group). In the hypothermia-preconditioned group, livers were perfused with hypothermic buffer (cycle of 10 min at 22 °C plus 10 min at 37 °C) and the other group was perfused at 37 °C. Both groups were then submitted to 40 min of warm ischemia and 20 min of warm reperfusion. The level of tissue-damage indicators (alanine amino transferase, ALT; lactate dehydrogenase, LDH; and proteins), oxidative stress markers (thiobarbituric acid-reactive substances, TBARS; advanced oxidation protein products, AOPP; and glutathione, GSH) were measured in aliquots of perfusate sampled at different time intervals. Histological determinations and oxidative stress biomarkers in homogenized liver (AOPP; TBARS; nitric oxide derivatives, NO_x; GSH and glutathione disulphide, GSSG) were also made in the tissue at the end. Results showed that both damage and oxidant indicators significantly decreased while antioxidant increased in hypothermic preconditioned livers. In addition, homogenized liver determinations and histological observations at the end of the protocol corroborate the results in the perfusate, confirming the utility of the perfusate as a non-invasive method. In conclusion, hypothermic preconditioning attenuates oxidative damage and appears to be a promising strategy to protect the liver against IR injury.

Is immunosuppression, induced by neonatal thymectomy, compatible with poor reproductive performance in adult male rats?

With increasing knowledge that the immune system has a major impact on reproductive ‎health, the potential for cells arising in organs such as the thymus to alleviate oxidative stress ‎has been revealed. This study addresses the impact of neonatal thymectomy on male ‎reproductive function in pubertal and adult animals. Neonatal Sprague Dawley rats were allotted to four treatments consisting of fully thymectomized, partially thymectomized, intact, and sham-operated rats. Half of the rats in each treatment were sacrificed at 40 and the other half at 80 days of age. Testicular volume, ventral prostate and spleen weight, several sperm attributes (concentration, motility, livability, membrane integrity, sperm penetration into mucus, total antioxidant capacity, mitochondrial dehydrogenase activity), plasma superoxide dismutase, glutathione, and testosterone level as well as fertility decreased in thymectomized rats. Adrenal gland weight, sperm malondialdehyde level, indices of oxidative stress, sperm abnormality, testicular and sperm lipid peroxidation, protein carbonylation, and sperm reactive oxygen species generation increased in thymectomized rats. In thymectomized rats, the testes contained high levels of malondialdehyde but low levels of glutathione and ferric-reducing antioxidant power. Epididymal sperm reactive oxygen species, blood lipid peroxidation, and oxidative stress indices ‎‎in blood and spermatozoa were highest in fully thymectomized, intermediate ‎in partially thymectomized, and lowest in both pubertal and mature control rats. Blood levels of superoxide dismutase, lipid peroxidation indices, and ‎testosterone, and mitochondrial adenosine triphosphate and ‎dehydrogenase activities in epididymal spermatozoa were lowest in fully thymectomized, ‎intermediate in partially thymectomized, and highest in both pubertal and mature control rats.‎ The data indicated that increased oxidative stress and mitochondrial dysfunction might play a role in the mechanism of immunosuppression-induced testicular and sperm abnormalities.

Does caffeine influence the anticholinesterase and antioxidant properties of donepezil? Evidence from in vitro and in vivo studies

Caffeine is adjudged world's most consumed pharmacologically active food component. With reports of the potential cognitive enhancing properties of caffeine, we sought to investigate if caffeine can influence the anticholinesterase and antioxidant properties of donepezil-a selective acetylcholinesterase (AChE) inhibitor used in the management of Alzheimer's disease (AD). In vitro, we investigated the effect of donepezil (DON), caffeine (CAF) and their various combinations on the activity of AChE in rat brain homogenate, as well as determined their antioxidant properties. In vivo, two rat groups were administered single oral dose of DON (5 mg/kg) and CAF (5 mg/kg) separately, while three groups, each received 5 mg/kg DON plus either 5, 50 or 100 mg/kg CAF for three hours, after which the rats were sacrificed and brain isolated. Results show that CAF concentration dependently and synergistically increased the anticholinesterase properties of DON in vitro. Also, CAF produced a significant influence on investigated in vitro antioxidant properties of DON. Furthermore, rats administered 5 mg/kg CAF and DON produced no significant difference in AChE activity compared to rats administered DON alone. However, co-administration of either 50 or 100 mg/kg CAF with DON lead to higher AChE activity compared to both control and DON groups. In addition, DON, CAF and their various combinations augmented brain antioxidant status in treated rats. We conclude that while low caffeine consumption may improve the antioxidant properties of donepezil without having a significant influence on its anticholinesterase effect, moderate-high caffeine consumption could also improve the antioxidant properties of donepezil but reduce its anticholinesterase effect; nevertheless, a comprehensive clinical trial is essential to fully explore these possibilities in human AD condition.

Effect of dietary polyphenol-rich grape seed on growth performance, antioxidant capacity and ileal microflora in broiler chicks

In this study, we examined the effect of dietary supplementation with grape seed (GS) on the performance, carcass traits, plasma biochemistry, antioxidant status and ileal microflora in broilers. Experiment diets included a control diet (without additive) and three levels of GS powder (10, 20 and 40 g/kg of diet). Each diet was fed to a total of 300 one-day-old Cobb-500 chicks for 42 days. The addition of 20 g/kg of GS to the basal diet increased final body weight and body weight gain, improved the feed conversion ratio and did not affect feed intake. Dietary 20 g GS significantly increased (p < .05) the percentage of carcass yield %, dressing % and gizzard. However, the addition of 40 g/kg of GS significantly reduced the percentage of abdominal fat in the birds. Diets supplemented with GS showed the lowest content of ether extract compared with the control group (p < .05). The physical characteristics of meat and the chemical composition of DM, CP and ash were not significantly influenced by treatments. In the GS groups, plasma protein, albumin, globulin, aspartate aminotransferase and alanine aminotransferase concentrations showed no significant change compared with the control group. Broilers fed a diet supplemented with GS had lower levels of plasma glucose, total lipids, triglycerides and cholesterol compared with the control birds (p < .05). The addition of 40 g of GS significantly (p < .05) enhanced the activity of reduced glutathione, catalase, superoxide dismutase, glutathione peroxidase and GST, and correlated with significantly decreased thiobarbituric acid-reactive substances levels compared with the control group. The value of ileal pH was not significantly affected by the GS levels. Broilers fed diets supplemented with GS had lower ileal Streptococcus spp. and Escherichia coli populations but higher Lactobacillus spp. populations (p < .05). No adverse effects on birds' health were detected due to the use of GS. Thus, GS could be recommended as an herbal supplement in the diet of broiler chickens to improve performance, reduce blood lipids, enhance antioxidant capacity and decrease detrimental bacteria in the ileum.

The influence of feeding purple wheat with higher content of anthocyanins on antioxidant status and selected enzyme activity of animals

The influence of anthocyanins on antioxidant activity and liver function was measured in three different animal species (rats, chickens and fish). Purple Konini wheat with the total anthocyanin content (TAC) of 41.70 mg/kg was fed to the experimental groups of animals (rats n = 32; chickens n = 32; fish n = 20). The same numbers of animals (control groups) were fed common wheat with TAC of 24.95 mg/kg. At the end of the experiment, the animals were killed and blood and liver tissues were taken for biochemical analyses. The liver enzyme activities were measured in blood. Antioxidant activity in the liver tissue was measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl test), FR (Free Radicals method), FRAP (Ferric Reducing Antioxidant Power method), and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) test. Significantly higher values (P< 0.05) measured by the DPPH and FR methods were determined in the liver from rats fed Konini wheat. The chickens fed Konini wheat showed significantly different values using DPPH, FR and ABTS methods. No significant differences were found in hepatopancreases of fish. Animals fed Konini wheat showed a tendency to lower liver enzyme activities in general, but a significant difference was found only in gamma-glutamyl transferase activity in the chicken’s blood. Our results suggest that feeding a higher content of anthocyanins can improve the antioxidant activity and function of the liver tissue.

Microbial Quality, Safety, and Pathogen Detection by Using Quantitative PCR of Raw Salad Vegetables Sold in Dhanbad City, India

Consumption of ready-to-eat fresh vegetables has increased worldwide, with a consequent increase in outbreaks caused by foodborne pathogens. In the Indian subcontinent, raw fresh vegetables are usually consumed without washing or other decontamination procedures, thereby leading to new food safety threats. In this study, the microbiological quality and pathogenic profile of raw salad vegetables was evaluated through standard protocols. In total, 480 samples (60 each of eight different salad vegetables) of cucumber, tomato, carrot, coriander, cabbage, beetroot, radish, and spinach were collected from different locations in Dhanbad, a city famous for its coal fields and often called the "Coal Capital of India." The samples were analyzed for total plate count, total coliforms, Escherichia coli , E. coli O157:H7, Listeria monocytogenes , and Salmonella spp. Incidences of pathogens were detected through quantitative PCR subsequent to isolation. Results showed that 46.7% (for total plate counts) and 30% (for total coliforms) of samples were unacceptable for consumption per the Food Safety and Standards Authority of India. Pathogenic microorganisms were detected in 3.7% of total samples. E. coli O157:H7 was detected in three samples of spinach (2) and beetroot ( 1 ); L. monocytogenes was detected in 14 samples of spinach ( 8 ), tomato ( 3 ), cucumber ( 2 ), and radish ( 1 ); and Salmonella spp. were detected in 16 samples of spinach ( 7 ), tomato ( 3 ), beetroot ( 2 ), cucumber ( 2 ), carrot ( 1 ), and radish ( 1 ). Pathogens were not detected in any of the cabbage and coriander samples.

Haematological, Biochemical and Antioxidant Changes in Wistar Rats Exposed to Dichlorvos Based Insecticide Formulation Used in Southeast Nigeria

The indiscriminate use of pesticide is a treat to non-target organisms. This study evaluates the haematological and biochemical changes induced by inhalation of local Nigerian dichlorvos insecticide on rats. The rats were randomly assigned to a control group which received only food and water and a test group which, in addition to food and water, was exposed to the pesticide for a period of 4 h daily for 28 days, after which exposure was discontinued for seven days. Five animals were sacrificed from each group on days 1, 7, 14, 21, 28 and 35, and blood was collected by cardiac puncture for haematological, biochemical and antioxidant analysis. Results obtained showed lowered values of red blood cell count (RBC), packed cell volume (PCV), haemoglobin, mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC) (p < 0.05) with increased white blood cell count (WBC) and platelet counts after day 14 when compared to the control group. Liver enzymes aspartate amino transaminase (AST) and alanine amino transaminase (ALT) were higher in the exposed rats compared to the control group (p < 0.05). Urea and creatinine concentrations increased significantly after day 1 and at day 28, while superoxide dismutase (SOD), gluthathione (GSH) and catalase (CAT) activity increased significantly compared to the control after day 1, day 14 and day 21, respectively. The RBC, PCV and haemoglobin values of all exposed rats were restored to normal following withdrawal of the pesticide, though AST, ALT, urea, creatinine and, glutathione values remained significantly high compared to the control. Inhalation of the local insecticide is toxic to the blood, liver and kidney of laboratory rats and may be deleterious to human health following long-term exposure.

Drying Methods Alter Angiotensin-I Converting Enzyme Inhibitory Activity, Antioxidant Properties, and Phenolic Constituents of African Mistletoe (Loranthus bengwensis L) Leaves

This study investigated the most appropriate drying method (sun drying, oven drying, or air drying) for mistletoe leaves obtained from almond tree. The phenolic constituents were characterized using high-performance liquid chromatography–diode array detector, while the inhibitory effect of the aqueous extracts of the leaves on angiotensin-I converting enzyme (ACE) was determined in vitro as also the antioxidant properties. Oven-dried extract (kidney [276.09 μg/mL] and lungs [303.41 μg/mL]) had the highest inhibitory effect on ACE, while air-dried mistletoe extract (kidney [304.47 μg/mL] and lungs [438.72 μg/mL]) had the least. Furthermore, the extracts dose-dependently inhibited Fe2+ and sodium nitroprusside-induced lipid peroxidation in rat’s heart and kidney. Also, all extracts exhibited antioxidative properties as typified by their radical scavenging and Fe-chelating ability. Findings from this study revealed that oven drying is the best of the 3 drying methods used for mistletoe obtained from almond host tree, thus confirming that diversity in drying methods leads to variation in phenolic constituents and biological activity of plants.

Hypothermia can reverse hepatic oxidative stress damage induced by hypoxia in rats

Our previous findings demonstrated that hypothermia enhances the reduction potential in the liver and helps to maintain the plasmatic antioxidant pool. Here, we aimed to elucidate if hypothermia protects against hypoxia-induced oxidative stress damage in rat liver. Several hepatic markers of oxidative stress were compared in three groups of animals (n = 8 in each group): control normothermic group ventilated with room air and two groups under extreme hypoxia (breathing 10 % O₂), one kept at normothermia (HN) (37 °C) and the other under deep hypothermia (HH) (central body temperature of 21-22 °C). Hypoxia in normothermia significantly increased the levels of hepatic nitric oxide, inducible nitric oxide synthase expression, protein oxidation, Carbonilated proteins, advanced oxidation protein products, 4-hydroxynonenal (HNE) protein adducts, and lipid peroxidation when compared to the control group (p < 0.05). However, when hypoxia was induced under hypothermia, results from the oxidative stress biomarker analyses did not differ significantly from those found in the control group. Indeed, 4-HNE protein adduct amounts were significantly lower in the HH versus HN group (p < 0.05). Therefore, hypothermia can mitigate hypoxia-induced oxidative stress damage in rat liver. These effects could help clarify the mechanisms of action of therapeutic hypothermia.

Dietary arginine and N-carbamylglutamate supplementation enhances the antioxidant statuses of the liver and plasma against oxidative stress in rats

N-Carbamylglutamate (NCG), an effective precursor of arginine (ARG), can enhance ARG synthesis, increase intestinal growth, and improve reproductive performance. However, the antioxidant effect of NCG remains largely unknown. This study aims to survey the effects of ARG and NCG supplementation on the antioxidant statuses of the liver and plasma in rats under oxidative stress. Rats were fed for 30 days with one of the three iso-nitrogenous diets: basal diet (BD), BD plus 1% ARG, and BD plus 0.1% NCG. On day 28, half of the rats fed with BD were intraperitoneally injected with 12 mg per kg body weight of diquat (diquat group) and the other half was injected intraperitoneally with sterile 0.9% NaCl solution (control group). The other diet groups also received an intraperitoneal injection of 12 mg per kg body weight of diquat, as follows: diquat + 1% ARG (DT + ARG), and diquat + 0.1% NCG (DT + NCG). Rat liver and plasma samples obtained 48 h after diquat injection were analyzed. Results indicated that diquat significantly affected the plasma conventional biochemical components (relative to the controls), which were partially alleviated in both the DT + ARG and DT + NCG groups (P < 0.05). Diquat also significantly decreased the glutathione (GSH) content (by 30.0%), and decreased anti-superoxide anion (ASA; by 13.8%) and anti-hydroxyl radical (AHR; by 38.9%) abilities in the plasma, and also decreased catalase (CAT) activity both in the liver (by 17.5%) and plasma (by 33.4%) compared with the control group. By contrast, diquat increased the malondialdehyde (MDA) content (by 23.0%) in the plasma (P < 0.05) compared with the control group. Relative to those of the diquat group, higher CAT activity and GSH content were noted in the plasma of the DT + ARG group and in the liver of both DT + ARG and DT + NCG groups (P < 0.05). Furthermore, the DT + ARG group exhibited significantly enhanced plasma ASA activity (P < 0.05). The DT + NCG group showed significantly improved total antioxidant capacity (T-AOC) in the liver and plasma (P < 0.05). Increased GSH content and elevated ASA and AHR activities were also found, but the MDA content in the plasma was depleted (P < 0.05). Compared with the DT + ARG group, the DT + NCG group showed increased liver and plasma T-AOC, enhanced plasma AHR activity, increased liver ASA activity, and decreased plasma MDA content (P < 0.05). Overall, supplementation of 1% ARG and 0.1% NCG can partially protect the liver and plasma from oxidative stress. Furthermore, compared with 1% ARG, 0.1% NCG more effectively alleviated oxidative stress.

Sorghum [Sorghum bicolor (L.) Moench] leaf sheath dye protects against cisplatin-induced hepatotoxicity and oxidative stress in rats

This study sought to determine the protective effect of dietary inclusion of sorghum leaf sheath dye on cisplatin-induced hepatotoxicity and oxidative stress in rats. Adult male rats were randomly divided into four groups with six animals in each group. Groups I and II were fed a basal diet, while groups III and IV were fed diets containing 0.5% and 1% sorghum leaf sheath dye, respectively, for 20 days before cisplatin administration. Hepatotoxicity was induced by a single dose of cisplatin (7 mg/kg body weight, i.p.), and the experiment was terminated at 3 days after cisplatin injection. The liver and plasma were studied for hepatotoxicity and antioxidant capacity. Cisplatin caused a significant (P<.05) alteration in plasma and liver enzymatic (catalase, glutathione-S-transferase [GST], and superoxide dismutase [SOD]) and nonenzymatic (glutathione [GSH] and vitamin C) antioxidant indices with a concomitant increase in the malondialdehyde (MDA) content; however, there was a significant (P<.05) restoration of the antioxidant status coupled with a significant (P<.05) decrease in the tissue MDA content, after consumption of diets containing sorghum leaf sheath dye. Furthermore, dietary inclusion of sorghum leaf sheath dye caused a marked reduction in the activities of alanine aminotransferase and aspartate aminotransferase after cisplatin administration. However, the ability of the dye to prevent significant cisplatin-induced alteration of both plasma and liver antioxidant indices suggests an antioxidant mechanism of action. Hence, this protective effect of Sorghum bicolor leaf sheath dye against cisplatin-induced hepatotoxicity in rats reflects its potential and beneficial role in the prevention of liver damage associated with cisplatin administration.

Modulatory effects of dietary inclusion of garlic (Allium sativum) on gentamycin-induced hepatotoxicity and oxidative stress in rats

OBJECTIVE

To investigate the ameliorative effect of dietary inclusion of garlic (Allium sativum) on gentamycin-induced hepatotoxicity in rats.

METHODS

Adult male rats were randomly divided into four groups with six animals in each group. Groups 1 and 2 were fed basal diet while Groups 3 and 4 were fed diets containing 2% and 4% garlic respectively for 27 d prior to gentamycin administration. Hepatotoxicity was induced by the intraperitoneal administration of gentamycin (100 mg/kg body weight) for 3 d. The liver and plasma were studied for hepatotoxicity and antioxidant indices.

RESULTS

Gentamycin induces hepatic damage as revealed by significant (P<0.05) elevation of liver damage marker enzymes (aspartate transaminase and alanine aminotransferase) and reduction in plasma albumin level. Gentamycin also caused a significant (P<0.05) alteration in plasma and liver enzymatic (catalase, glutathione and super oxygen dehydrogenises) and non-enzymatic (glutathione and vitamin C) antioxidant indices with concomitant increase in the malondialdehyde content; however, there was a significant (P<0.05) restoration of the antioxidant status coupled with significant (P<0.05) decrease in the tissues' malondialdehyde content, following consumption of diets containing garlic.

CONCLUSIONS

These results suggest that dietary inclusion of garlic powder could protect against gentamycin-induced hepatotoxicity, improve antioxidant status and modulate oxidative stress; a function attributed to their phenolic constituents.

Tetracarpidium conophorum (Mull.Arg) Hutch & Dalziel inhibits FeSO4-induced lipid peroxidation in rat's genitals

Background

To search for new sources of safe and inexpensive antioxidant agents which can be used to treat various oxidative stress - related diseases, the phenolic contents of leaf of Tetracarpidium conophorum were characterized and its effect on pro-oxidant induced oxidative stress in rat’s genitals for the first time was investigated.

Methods

The aqueous extract of the plant was prepared, the antioxidant activities of the extract were then evaluated using spectrophotometric method.

Results

The result revealed that the introduction of aqueous extract of the plant caused significant concentration-dependent decrease (P < 0.05) in the MDA content of the Fe²⁺ -stressed testes and penis homogenates. The least MDA production occurred at the highest concentration of the extract (0.625 mg/mL). However, characterization of the extract with HPLC revealed that its major constituents were gallic acid, catechin, chlorogenic acid, caffeic acid, coumarin, rutin, quercitrin, quercetin, kaempferol and luteolin. Also, the result revealed that the ABTS* scavenging ability of the extract was 4.60 mmol/100 g while its vitamin C content was 23.49 mg/g which indicated that the plant is very rich in vitamin C. Furthermore, the extract scavenged DPPH, NO, OH* radicals and chelated Fe²⁺ in a dose-dependent manner.

Conclusion

The inhibitory effect of Tetracarpidium conophorum leaves could be attributed to the high levels of quercitrin, quercetin and luteolin and the mechanism through which these compounds possibly do this, could be by their radical scavenging abilities.

Development of a new catalase activity assay for biological samples using optical CUPRAC sensor

A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based 'cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC.

Effects of feeding polyphenol-rich winery wastes on digestibility, nitrogen utilization, ruminal fermentation, antioxidant status and oxidative stress in wethers

Four wethers were used in a 4 × 4 Latin square design experiment to evaluate the availability of two types of winery wastes, winery sediment and grape pomace, as ruminant feeds possessing antioxidant activities. Each wether was assigned to one of the following four treatments: (i) 75 g/kg winery sediment (WS) on a dry matter (DM) basis; (ii) 166 g/kg DM winery grape pomace (WP); (iii) control diet (CD; 17 g/kg DM soybean meal);and (iv) only tall fescue hay (TFH; no additive). Winery sediment and grape pomace had high levels of polyphenols and of radical scavenging activities. Feeding with winery sediment and grape pomace did not negatively affect the intake, but it depressed crude protein (CP) digestibility compared with CD (P = 0.052 and P < 0.01 for WS and WP, respectively). Polyphenols in winery wastes decreased ruminal ammonia production (P = 0.089 and P < 0.05), likely due to their inhibitive effect on microbial activities in the rumen. The addition of winery sediment and grape pomace decreased urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG; an index of oxidative damages) excretion per day (P < 0.05 and P = 0.059). The results indicated that winery sediment and grape pomace could alter nitrogen metabolism and/or act as new antioxidants for ruminants.

In Vitro Studies on the Antioxidant Property and Inhibition of α-Amylase, α-Glucosidase, and Angiotensin I-Converting Enzyme by Polyphenol-Rich Extracts from Cocoa (Theobroma cacao) Bean

Background. This study sought to investigate the antidiabetic and antihypertensive mechanisms of cocoa (Theobroma cacao) bean through inhibition of α-amylase, α-glucosidase, angiotensin-1 converting enzyme, and oxidative stress. Methodology. The total phenol and flavonoid contents of the water extractable phytochemicals from the powdered cocoa bean were determined and the effects of the extract on α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities were investigated in vitro. Furthermore, the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH), 2,2..-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH), and nitric oxide (NO)] scavenging ability and ferric reducing antioxidant property of the extract were assessed. Results. The results revealed that the extract inhibited α-amylase (1.81 ± 0.22 mg/mL), α-glucosidase (1.84 ± 0.17 mg/mL), and angiotensin-1 converting enzyme (0.674 ± 0.06 mg/mL [lungs], 1.006 ± 0.08 mg/mL [heart]) activities in a dose-dependent manner and also showed dose-dependent radicals [DPPH (16.94 ± 1.34 mg/mL), NO (6.98 ± 0.886 mg/mL), OH (3.72 ± 0.26 mg/mL), and ABTS (15.7 ± 1.06 mmol/TEAC·g] scavenging ability. Conclusion. The inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the cocoa bean extract could be part of the possible mechanism by which the extract could manage and/or prevent type-2 diabetes and hypertension.