Gastroprotective and antioxidant effects of Eremurus spectabilis Bieb. methanol extract and its isolated component isoorientin on indomethacin induced gastric ulcers in rats

Abstract Purpose: To investigate the gastroprotective effect of methanol extract of E. spectabilis and its major component isoorientin. Methods: Effects of isoorientin and methanol extract of E. spectabilis were investigated in indomethacin-induced gastric damage model on rats. Famotidine was used as the standard antiulcer drug. Numerical density of ulcer areas and oxidative status were determined on stomach tissues of rats. Results: All doses of isoorientin and methanol extract decreased MDA level and increased SOD activity and GSH levels in the stomach tissue of rats. When numerical density of ulcer areas were analized, the 500 mg/kg dose of methanol extract (84%) exhibited a similar effect to 20 mg/kg dose of standart drug famotidine (87%). Conclusions: The gastroprotective effects of E. spectabilis and its major constituent isoorientin in rats for the first time. Detailed analyses suggested that potential antioxidant activity of both plant extract and isoorientin mediates the gastroprotective effect.

Melatonin ameliorates H2O2-induced oxidative stress through modulation of Erk/Akt/NFkB pathway

BACKGROUND: Improper control on reactive oxygen species (ROS) elimination process and formation of free radicals causes tissue dysfunction. Pineal hormone melatonin is considered a potent regulator of such oxidative damage in different vertebrates. Aim of the current communication is to evaluate the levels of oxidative stress and ROS induced damage, and amelioration of oxidative status through melatonin induced activation of signaling pathways. Hepatocytes were isolated from adult Labeo rohita and exposed to H2O2 at three different doses (12.5, 25 and 50 µM) to observe peroxide induced damage in fish hepatocytes. Melatonin (25, 50 and 100 µg/ml) was administered against the highest dose of H2O2. Enzymatic and non-enzymatic antioxidants such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) was measured spectrophotometrically. Expression level of heat shock proteins (HSP70 and HSP90), HSPs-associated signaling molecules (Akt, ERK, cytosolic and nuclear NFkB), and melatonin receptor was also measured by western blotting analysis. RESULTS: H2O2 induced oxidative stress significantly altered (P < 0.05) MDA and GSH level, SOD and CAT activity, and up regulated HSP70 and HSP90 expression in carp hepatocytes. Signaling proteins exhibited differential modulation as revealed from their expression patterns in H2O2-exposed fish hepatocytes, in comparison with control hepatocytes. Melatonin treatment of H2O2-stressed fish hepatocytes restored basal cellular oxidative status in a dose dependent manner. Melatonin was observed to be inducer of signaling process by modulation of signaling molecules and melatonin receptor. CONCLUSIONS: The results suggest that exogenous melatonin at the concentration of 100 µg/ml is required to improve oxidative status of the H2O2-stressed fish hepatocytes. In H2O2 exposed hepatocytes, melatonin modulates expression of HSP70 and HSP90 that enable the hepatocytes to become stress tolerant and survive by altering the actions of ERK, Akt, cytosolic and nuclear NFkB in the signal transduction pathways. Study also confirms that melatonin could act through melatonin receptor coupled to ERK/Akt signaling pathways. This understanding of the mechanism by which melatonin regulates oxidative status in the stressed hepatocytes may initiate the development of novel strategies for hepatic disease therapy in future.

The potential role of amlodipine on experimentally induced bacterial rhinosinusitis / O papel potencial da amlodipina na rinossinusite bacteriana induzida experimentalmente

Abstract Introduction: Antibiotics are frequently used for the treatment of rhinosinusitis. Concerns have been raised regarding the adverse effects of antibiotics and growing resistance. The lack of development of new antibiotic compounds has increased the necessity for exploration of non-antibiotic compounds that have antibacterial activity. Amlodipine is a non-antibiotic compound with anti-inflammatory activity. Objective: In this study we aimed to investigate the potential role of amlodipine in the treatment of rhinosinusitis by evaluating its effects on tissue oxidative status, mucosal histology and inflammation. Methods: Fifteen adult albino guinea pigs were inoculated with Staphylococcus aureus and treated with saline, cefazolin sodium, or amlodipine for 7 days. The control group was composed by five healthy guinea pigs. Animals were sacrificed after the treatment. Histopathological changes were identified using Hematoxylin-Eosin staining. Inflammation was assessed by Polymorphonuclear Leukocyte infiltration density. Tissue levels of antioxidants (superoxide dismutase, glutathione) and an oxidative product (malondialdehyde) were determined. Results: In rhinosinusitis induced animals, amlodipine reduced loss of cilia, lamina propria edema and collagen deposition compared to placebo (saline) and although not superior to cefazolin, amlodipine decreased polymorphonuclear leukocyte infiltration. The superoxide dismutase activity and glutathione levels were reduced, whereas the malondialdehyde levels were increased significantly in all three-treatment groups compared to the control group. Amlodipine treated group showed significantly increased superoxide dismutase and glutathione levels and decreased malondialdehyde levels compared to all treatment groups. Conclusion: The non-antibiotic compound amlodipine may have a role in acute rhinosinusitis treatment through tissue protective, antioxidant and anti-inflammatory mechanisms.

Resumo Introdução: Antibióticos são frequentemente usados para o tratamento de rinossinusite. Questões têm sido levantadas sobre os efeitos adversos dos antibióticos e a resistência crescente. A falta de desenvolvimento de novos compostos antibióticos aumentou a necessidade da exploração de compostos não antibióticos que têm atividade antibacteriana. A amlodipina é um composto não antibiótico com atividade anti-inflamatória. Objetivo: O objetivo desse estudo foi investigar o papel potencial da amlodipina no tratamento da rinossinusite, avaliando seus efeitos sobre o estado oxidativo do tecido, histologia da mucosa e inflamação. Método: Quinze cobaias albinas adultas foram inoculadas com Staphylococcus aureus e tratadas com solução salina, cefazolina ou amlodipina durante sete dias. O grupo controle incluiu cinco cobaias saudáveis. Os animais foram sacrificados após o tratamento. Alterações histopatológicas foram identificadas com a coloração de hematoxilina-eosina. A inflamação foi avaliada pela densidade de infiltração de leucócitos polimorfonucleares. Foram determinados os níveis teciduais de antioxidantes (superóxido dismutase, glutationa) e um produto de oxidação (malondialdeído). Resultados: Em animais com rinossinusite induzida, a amlodipina reduziu a perda dos cílios, edema da lâmina própria e deposição de colágeno em comparação com o grupo placebo (solução salina) e embora não seja superior à cefazolina, a amlodipina diminuiu a infiltração de leucócitos polimorfonucleares. Os níveis de atividade da superóxido dismutase e glutationa foram reduzidos, enquanto os níveis de malondialdeído aumentaram significativamente nos três grupos de tratamento em comparação ao grupo controle. O grupo tratado com amlodipina apresentou aumento significante dos níveis de superóxido dismutase e glutationa e diminuição dos níveis de malondialdeído em comparação com todos os grupos de tratamento. Conclusão: O composto não antibiótico amlodipina pode ter um papel no tratamento da rinossinusite aguda através de mecanismos protetores de tecido, antioxidantes e anti-inflamatórios.

Impacto da suplementação de vitamina C sobre níveis de peroxidação lipídica e glutationa reduzida em tecido hepático de camundongos com imunossupressão induzida por ciclofosfamida / Impact of vitamin C supplementation on lipid peroxidation and reduced glutathione levels in the liver tissue of mice with cyclophosphamide-induced immunosuppression

RESUMO Objetivo: Investigar os efeitos da vitamina C sobre níveis de peroxidação lipídica e glutationa reduzida em tecido hepático de camundongos imunossuprimidos por ciclofosfamida. Métodos: O estudo foi realizado em camundongos Swiss, fêmeas, com 45 dias de idade, separados em quatro grupos com oito animais cada. Grupos: controle (água destilada), vitamina C (50 mg/kg), ciclofosfamida (100 + 150 mg/kg) e tratamento (vitamina C 50 mg/kg + ciclofosfamida 100 +150 mg/kg). Todas as aplicações foram via intraperitoneal. O ensaio biológico teve duração de seis dias, sendo o sétimo a eutanásia dos animais. As análises bioquímicas de peroxidação lipídica (quantificação de substâncias reativas ao ácido tiobarbitúrico) e glutationa reduzida (estimativa de tiois não proteicos) foram realizadas em tecido hepático. Resultados: A ciclofosfamida causou aumento significativo (p<0,0001) nos níveis de peroxidação lipídica. Não foram observadas alterações significativas nos grupos tratados com vitamina C. A ciclofosfamida por si só, não alterou níveis de glutationa reduzida. A vitamina C causou a redução do nível de glutationa reduzida em relação ao controle tanto nos animais que receberam ciclofosfamida quanto nos que não receberam. No entanto, nos grupos tratados com o quimioterápico houve uma interação entre a droga e a vitamina, ou seja, o quimioterápico intensificou a diminuição da glutationa reduzida provocada pela vitamina C. Conclusão: A ciclofosfamida, na dose e período utilizados, foi capaz de induzir o dano oxidativo verificado pelo aumento da peroxidação lipídica. A vitamina C, na dose de 50 mg/kg de peso, não apresentou potencial para proteger contra o dano oxidativo provocado pelo quimioterápico.

ABSTRACT Objective: To investigate the effects of vitamin C supplementation on the levels of lipid peroxidation and reduced glutathione in the liver tissue of mice immunosuppressed with cyclophosphamide. Methods: Thirty-two 45-day-old female Swiss mice were divided into four groups of eight animals each as follows: control (distilled water); vitamin C (50 mg/kg); cyclophosphamide (100 + 150 mg/kg); and treatment (vitamin C 50 mg/kg + cyclophosphamide 100 +150 mg/kg). The substances were provided intraperitoneally for six days, and on the seventh day, the mice were euthanized. The biochemical analyses of lipid peroxidation (quantification of thiobarbituric acid-reactive substances) and reduced glutathione (estimate of non-protein thiols) were performed on liver tissue. Results: Cyclophosphamide increased the levels of lipid peroxidation (p<0.0001). Significant changes were not found in the groups treated with vitamin C. Cyclophosphamide alone did not affect the levels of reduced glutathione. Compared with the control group, vitamin C reduced the levels of reduced glutathione in animals that received or not cyclophosphamide. Vitamin C interacted with cyclophosphamide, that is, the chemotherapeutic agent further decreased the lower levels of reduced glutathione secondary to vitamin C intake. Conclusion: Cyclophosphamide, in the study dosage and duration, was capable of inducing oxidative damage, verified by increased lipid peroxidation. A vitamin C dosage of 50mg/kg of body weight did not protect against the oxidative damage caused by the chemotherapeutic agent.

Can thiamine pyrophosphate prevent desflurane induced hepatotoxicity in rats?

ABSTRACT PURPOSE : To investigate the effects of thiamine pyrophosphate (TPP) against desflurane induced hepatotoxicity. METHODS : Thirty experimental animals were divided into groups as healthy (HG), desflurane control (DCG) , TPP and desflurane group (TDG). 20 mg/kg TPP was injected to intraperitoneally TDG. After one hour of TPP administration, desflurane was applied for two hours. After 24 hours, liver tissues of the animals killed with decapitation were removed. The oxidant/antioxidant levels and ALT, AST and LDH activities were measured. The histopathological examinations were performed in the liver tissues for all rats. RESULTS : Notwithstanding the levels of oxidants and liver enzymes were significantly increased (p<0.0001), antioxidant levels were significantly decreased in DCG (p<0.0001). On contrary to the antioxidant parameters were increased (p<0.05) the oxidant parameters and liver enzymes were decreased in TDG (p<0.0001). Whereas multiple prominent, congestion, hemorrhage and dilatation were observed in sinusoids and lymphocyte-rich inflammation results in the centrilobular and portal areas of liver tissue in DCG, these findings were observed less frequently in TDG. CONCLUSİON : Thiamine pyrophosphate prevented liver oxidative damage induced with desflurane and may be useful in prophylaxis of desflurane induced hepatotoxicity.

Effect of organo and inorganic lithium salt on human blood plasma glutathione- a comparative study

Investigation of toxicological effect of various metals is the field of interest for toxicological scientists since four to five decades and especially the toxicological effect of those drugs containing metals and there use is common because there is no other choice except to use these metal containing drugs. Inorganic as well as organic salts of lithium are commonly used in prophylaxis and treatments of many psychiatric disorders. The aim of the present study was to see the difference between the effect of organic and inorganic salt of lithium commonly used in psychiatric disorders on the GSH of human blood plasma. It is the scientific fact that ionic dissociation of organic and inorganic salts of any metal is always quite different hence to prove this fact, the effect of lithium citrate [organic salt of lithium] and lithium carbonate [inorganic salt of lithium] was investigated on human blood plasma GSH to find the difference between the effect of two. Ellman's method was used for the quantification of glutathione contents in plasma. It was found that lithium citrate decrease plasma GSH contents less than lithium carbonate indicating that organic salts of lithium are safe than inorganic salts of lithium when are used in psychiatric disorders. Further to analyze the effect of organic and inorganic salt of lithium on blood plasma GSH with the increase in incubation time was also evaluated and was found that both concentration and time dependent effect of organic salt of lithium shows that this salt has decreased plasma GSH contents of human blood less than inorganic salt of lithium either by promoting oxidation of GSH into GSSG or by lithium glutathione complex formation. These results suggest the physicians that the use of organic lithium salts is much safer than inorganic salts of lithium in terms of depletion of blood plasma GSH contents

Antiperoxidative properties of oil mixes of high ratio Omega-9:Omega-6 and low ratio Omega-6:Omega-3 after molar extraction in rats

PURPOSE: To evaluate the antioxidant and antiperoxidative effects of oil mixes of high ratio Omega-9:Omega-6 and low ratio Omega-6:Omega-3 in the third day after tooth extraction in rats. METHODS: Thirty-two male Wistar rats (270-310g) were randomly distributed in two groups: Control (n=24) and Test (n=8). Control group was divided into three subgroups (n=8): G1: Sham-Saline; G2: Saline; G3: Isolipid. G1 and G2 animals received NaCl 0.9% while G3 rats were treated with an isolipid mixture (alpha-linolenic acid - ALA) containing -6/-3 oils (8:1 ratio) and-9/-6 (0.4:1 ratio). Test group animals (G4) received oily mixtures (alpha-linolenic acid - ALA, docosahexaenoic acid - DHA, eicosapentaenoic acid - EPA) of -6/-3 (1.4:1 ratio) and -9/-6 (3.4:1 ratio). Saline and oils were administered by gavage during four days before and three days after first mandibular molar extraction. Following, samples (arterial blood and alveolar mucosa) were collected for glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) assays. RESULTS: Oil mixes induced a significant decrease in GSH and TBARS tissue and plasma concentrations in the third day post-surgery. CONCLUSION: Gavage administration of oil mixes of high ratio Omega-9:Omega-6 and low ratio Omega-6:Omega-3 after molar extraction in rats induces a significant decrease in lipid peroxidation. .

Calcium dobesilate may improve hemorheology in patients undergoing coronary artery bypass grafting / Dobesilato de cálcio pode melhorar hemorreologia em pacientes submetidos à cirurgia de revascularização miocárdica

BACKGROUND: Calcium dobesilate is an angioprotective agent that has positive effects on hemorheological parameters. It is an antioxidant that increases endothelial-derived vasodilator substance secretion, there are none that analyze its effects during the postoperative period of patients undergoing myocardial revascularization. OBJECTIVE: We aimed to determine the effects of calcium dobesilate on hemorheological parameters, such as reduced glutathione and malondialdehyde in patients with ischemic heart disease undergoing myocardial revascularization in the postoperative period. METHODS: One hundred and thirty-four patients operated for coronary heart disease were included in this study. Hemorheological, oxidant and antioxidant parameters were measured two days after surgery and after a period of treatment with calcium dobesilate. Then, 500 mg of calcium dobesilate was given twice a day to one group of 68 patients for three months. The control group was composed of 66 patients who did not receive this medication. RESULTS: The increase in the erythrocyte deformability index was found to be significant compared with both the pretreatment values and with the 1st and 2nd values of the control group after calcium dobesilate administration, whereas there were no significant changes in blood viscosity, glutathione (GSH) or malondialdehyde (MDA) values after the calcium dobesilate administration. The same improvement in the CCS class was observed in patients regardless of they received the calcium dobesilate treatment. CONCLUSION: In the present investigation, the same improvement in the CCS class was observed in patients regardless of they received the calcium dobesilate treatment. Improvements with calcium dobesilate were statistically significant only in the increase in erythrocyte flexibility.

ANTECEDENTES: O dobesilato de cálcio é um agente angioprotetor que tem efeitos positivos sobre os parâmetros hemorreológicos. É um antioxidante que aumenta a secreção endotelial derivada da substância vasodilatadora, não há nada que analisar os seus efeitos durante o período pósoperatório de pacientes submetidos a revascularização do miocárdio. OBJETIVO: Nosso objetivo foi determinar os efeitos de dobesilato de cálcio sobre os parâmetros hemorreológicos, tais como glutationa reduzida e malondialdeído em pacientes com doença cardíaca isquêmica submetidos a revascularização do miocárdio no pós-operatório. MÉTODOS: Cento e trinta e quatro pacientes operados por doença cardíaca coronária foram incluídos neste estudo. Parâmetros de oxidante, hemorreológicos e de antioxidantes foram medidos dois dias após a cirurgia e após um período de tratamento com o dobesilato de cálcio. Em seguida, 500 mg de dobesilato de cálcio foi administrado duas vezes por dia para um grupo de 68 pacientes durante três meses. O grupo controle foi composto por 66 pacientes que não receberam essa medicação. RESULTADOS: O aumento do índice de deformabilidade dos eritrócitos foi considerado significativo comparado com ambos os valores pré-tratamento e com os 1º e 2º valores do grupo controle após a administração dobesilato de cálcio, enquanto que não houve alterações significativas na viscosidade do sangue, na glutationa (GSH) ou malondialdeído (MDA) após a administração dobesilato de cálcio. A mesma melhoria na classe CCS foi observada em pacientes independentemente de terem recebido tratamento com dobesilato de cálcio. CONCLUSÃO: Na presente investigação, a mesma melhora na classe CCS foi observada em pacientes independentemente de terem recebido o tratamento com dobesilato de cálcio.

Effect of Inula racemosa root extract on cardiac function and oxidative stress against isoproterenol-induced myocardial infarction.

The cardioprotective potential of Inula racemosa root hydroalcoholic extract against isoproterenol-induced myocardial infarction was investigated in rats. The rats treated with isoproterenol (85 mg/kg, s.c.) exhibited myocardial infarction, as evidenced by significant (P<0.05) decrease in mean arterial pressure, heart rate, contractility, relaxation along with increased left ventricular end diastolic pressure, as well as decreased endogenous myocardial enzymatic and non-enzymatic antioxidants. Isoproterenol also significantly (P<0.05) induced lipid peroxidation and increased leakage of myocyte injury marker enzymes. Pretreatment with I. racemosa extract (50, 100 or 200 mg/kg per day, p.o.) for 21 consecutive days, followed by isoproterenol injections on days 19th and 20th significantly (P<0.05) improved cardiac function by increasing the heart rate, mean arterial pressure, contractility and relaxation along with decreasing left ventricular end diastolic pressure. Pretreatment with I. racemosa also significantly (P<0.05) restored the reduced form of glutathione and endogenous antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase from the heart, which were depleted after isoproterenol administration. In addition to restoration of antioxidants, I. racemosa significantly (P<0.05) inhibited lipid peroxidation and prevented the leakage of myocytes specific marker enzymes creatine phosphokinase-MB and lactate dehydrogenase from the heart. Thus, it is concluded that I. racemosa protects heart from isoproterenol-induced myocardial injury by reducing oxidative stress and modulating hemodynamic and ventricular functions of the heart. Present study findings demonstrate the cardioprotective effect of I. racemosa and support the pharmacological relevance of its use and cardioprotection mechanism in ischemic heart disease as well as substantiate its traditional claim

[Study of the prophylactic effects of amifostine on decrease of lung tissue injuries in the acute phase in rats exposed to sulfur mustard]

Inhalation of Sulfur mustard [HD] will cause lung epithelial inflammation and injury. There are different results from the prophylactic effects of amifostine [AM] on protection of lung epithelial tissue against HD. The aim of this study was to evaluate the prophylactic effects of AM on protection of rat lung tissue exposed to HD. In this study twenty Albino Wistar adult male rats weighting 200 +/- 20 grams were used. Rats were divided randomly into 4 groups [5 rats in each group] as below: Normal saline group [NS], AM group, HD group [0.25% HD] and HD+AM group. Normal saline and HD solution were injected by intra tracheal catheter. Animals in AM and HD+AM groups received AM by intra peritoneal injection for 14 days daily. All rats were killed after 14 days; parts of the base of right lungs were removed, fixed and processed for histological evaluation by Toluidine blue, H and E staining and apoptotic cell death study by the TUNEL Apoptosis Detection Kit. In addition, glutathione level was measured in all specimens. No significant differences were revealed between Saline and AM groups in any of the aforementioned tests. Significant reduction of mast cells in lung tissue of the HD+AM group was shown when compared to the HD group. Lung tissue inflammation in the HD group was significantly more severe as compared to HD+AM group. In addition, amifostine in HD+AM group could prevent excess reduction of GSH level. The number of apoptotic cells in the HD group was significantly higher than the HD+AM group. Administration of amifostine before exposure to HD in rats prevents collection of mast cells, and excess reduction of GSH level in lung tissue; in addition it can partially reduce pulmonary edema and alveolar cell death apoptosis

Antioxidant activity of aerial parts of tribulus alatus in rats

The antioxidant activity of alcoholic extract of Tribulus alatus was investigated by determination of blood glutathione, serum ascorbic acid and serum superoxide dismutase in rats. All groups treated with aerial parts without fruit, fruits and total herb showed a significant increase in all measured parameters [P<0.05]. Upon fractionation of the alcoholic extracts using solvents with different polarities, all fractions revealed a significant increase in serum superoxide dismutase [P<0.05]. On the other hand chloroformic fraction of aerial parts without fruit extract and ethylacetate fraction of fruits extract exhibited a significant increase in blood glutathione level. All fractions of fruits extract, chloroformic and ethylacetate fractions of aerial parts without fruit extract significantly increase the serum ascorbic acid concentration [P<0.05]

Amelioration of cisplatin induced nephrotoxicity in Swiss albino mice by Rubia cordifolia extract.

BACKGROUND: Cisplatin is one of the most effective chemotherapeutics against a wide range of cancers including head, neck, ovarian and lung cancers. But its usefulness is limited by its toxicity to normal tissues, including cells of the kidney proximal tubule. The purpose of the present study is to investigate whether the hydro-alcoholic extract of Rubia cordifolia could decrease the intensity of toxicity in Swiss albino mice. MATERIALS AND METHODS: Cisplatin at a dose of 12 mg/kg body wt was administered intraperitoneally to Swiss albino mice. Another set of animals was given hydro-alcoholic extract of Rubia cordifolia at different doses along with cisplatin treatment. The antioxidant levels, serum creatinine, serum urea etc. were analyzed. Results: The extract could significantly decrease the cisplatin induced nephrotoxicity as inferred from the tissue antioxidant status in the drug administered animals. Remarkable change was observed in serum creatinine and urea levels. Lipid peroxidation in the kidney and liver tissues was also considerably reduced in Rubia cordifolia extract treated animals. CONCLUSION: Hydro-alcoholic extracts of Rubia cordifolia are effective in reducing the renal damage caused by the cancer chemotherapeutic drug cisplatin. Since Rubia cordifolia has been in use as an important ingredient in the traditional Ayurvedic system of medicine, it could be safe and beneficial to use this herbal extract as an adjuvant to ameliorate renal damage in patients undergoing cancer chemotherapy with cisplatin.

effects of stylbene estrogen [hexestrol] on the glutathione redox system activity in albinos rats

The use of stylbene estrogens, which is not only for the aims of reproduction, but also in order to increase protein biosynthesis in domestic animals for feeding, unfortunately these estrogens can be transformed into toxic metabolites, such as carcinogens, electrophiles, hydroperoxides, etc... The obtained results have allowed us to study the role of glutathione redox cycle in detoxification and elimination of different toxic peroxides, arising from hexestrol [3, 4, -para-oxiphenyl-hexane] metabolism. The treatment with this stylbene estrogen induces a great change in this enzymatic system of glutathione. However, the reduced glutathione content decreases significantly in rat's liver and testicles, proportionally with the experimental period and with the studied hexestrol doses. Whereas, the combined significant increase in the glutathione peroxidase and the glutathione reductase activities appears also throughout the treatment, especially in 100 and 200 micro g/kg hexestrol doses. The proportional relationship between the decreased glutathione content and the increased glutathione peroxidase and glutathione reductase activities in rats injected with hexestrol confirms the participation of glutathione redox cycle in the detoxifying processes of continuously accumulated peroxides, resulting from the metabolism of this synthetic estrogen

Co-operative effect of glutathione depletion and selenium induced oxidative stress on API and NFkB expression in testicular cells in vitro: insights to regulation of spermatogenesis

Previous studies have shown that transcription factors, API and NFkB exert important roles in the process by which selenium regulates spermatogenesis. Glutathione, an intracellular thiol, acts as a source of reducing power and aids in maintenance of the cellular redox status. The activities of selenium are closely related to the availability of glutathione. Presently, mouse testicular cells were cultured in the presence of BSO, a known glutathione depletor, to generate oxidative stress. Selenium (Se) was added as sodium selenite to these cells at concentrations of 0.5 µM and 1.5 µM. It was observed that at 1.5 µM, Se acted as a pro-oxidant and significantly decreased the redox ratio. RT PCR analysis revealed that cjun, cfos expression increased in testicular cells cultured with Se compared to control. However, the major outcome was that the combined effect of Se supplementation and GSH depletion resulted in reduced expression of cjun and cfos while p65 expression increased. This suggests that selenium affects both these transcription factors differently. Our study indicates that though low levels of oxidative stress generated by moderate doses of selenium augments the expression of cjun and cfos, a robust increase in the ROS generation caused by the dual effect high levels of selenium and glutathione depletion leads to decrease in the expression of these genes. The present work substantiates our in vivo experiments and indicates the detrimental effect of excess selenium supplementation on male fertility.

Ginseng administration protects skeletal muscle from oxidative stress induced by acute exercise in rats

Enzymatic activity was analyzed in the soleus, gastrocnemius (red and white) and plantaris muscles of acutely exercised rats after long-term administration of Panax ginseng extract in order to evaluate the protective role of ginseng against skeletal muscle oxidation. Ginseng extract (3, 10, 100, or 500 mg/kg) was administered orally for three months to male Wistar rats weighing 200 ± 50 g before exercise and to non-exercised rats (N = 8/group). The results showed a membrane stabilizing capacity of the extract since mitochondrial function measured on the basis of citrate synthase and 3-hydroxyacyl-CoA dehydrogenase activities was reduced, on average, by 20 percent (P < 0.05) after exercise but the activities remained unchanged in animals treated with a ginseng dose of 100 mg/kg. Glutathione status did not show significant changes after exercise or treatment. Lipid peroxidation, measured on the basis of malondialdehyde levels, was significantly higher in all muscles after exercise, and again was reduced by about 74 percent (P < 0.05) by the use of ginseng extract. The administration of ginseng extract was able to protect muscle from exercise-induced oxidative stress irrespective of fiber type.

Pre-administration of beta-carotene protects tissue glutathione and lipid peroxidation status following exposure to gamma radiation.

The present study has been aimed to investigate the protective effect of beta-carotene against radiation-induced oxidative stress in mice tissues using lipid peroxidation and glutathione (GSH) as end points. Fourteen days oral priming administration of beta-carotene (35 mg/kg body weight) followed by an acute dose of gamma radiation (5 Gy) inhibited the augmented level of thiobarbituric acid reactive substance (TBARS) and a statistically significant protection against GSH depletion. Results evaluated from this study clearly indicate the antioxidative property of beta-carotene against gamma radiation, which is suggestive of free radical scavenging and singlet oxygen quenching.

Phenolic antioxidants attenuate hippocampal neuronal cell damage against kainic acid induced excitotoxicity.

Increasing evidence supports the role of excitotoxicity in neuronal cell injury. Thus, it is extremely important to explore methods to retard or reverse excitotoxic neuronal injury. In this regard, certain dietary compounds are beginning to receive increased attention, in particular those involving phytochemicals found in medicinal plants in alleviating neuronal injury. In the present study, we examined whether medicinal plant extracts protect neurons against excitotoxic lesions induced by kainic acid (KA) in female Swiss albino mice. Mice were anesthetized with ketamine and xylazine (200 mg and 2 mg/kg body wt. respectively) and KA (0.25 microg in a volume of 0.5 microl) was administered to mice by intra hippocampal injections. The results showed an impairment of the hippocampus region of brain after KA injection. The lipid peroxidation and protein carbonyl content were significantly (P < 0.05) increased in comparison to controls. Glutathione peroxidase (GPx) activity (EC 1.11.1.9) and reduced glutathione (GSH) content declined after appearance of excitotoxic lesions. As GPx and GSH represent a major pathway in the cell for metabolizing hydrogen peroxide (H2O2), their depletion would be expected to allow H2O2 to accumulate to toxic levels. Dried ethanolic plant extracts of Withania somnifera (WS), Convolvulus pleuricauas (CP) and Aloe vera (AV) dissolved in distilled water were tested for their total antioxidant activity. The diet was prepared in terms of total antioxidant activity of plant extracts. The iron (Fe3+) reducing activity of plant extracts was also tested and it was found that WS and AV were potent reductants of Fe3+ at pH 5 5. CP had lower Fe3+ reducing activity in comparison to WS and AV. Plant extracts given singly and in combination 3 weeks prior to KA injections resulted in a decrease in neurotoxicity. Measures of lipid peroxidation and protein carbonyl declined. GPx activity and GSH content were elevated in hippocampus supplemented with WS and combination of WS + CP + AV. However, when CP and AV were given alone, the changes in the GPx activity and GSH content were not significant. Although the major factors involved in these properties of phytochemicals remain to be specified, the finding of this study has suggested that phytochemicals present in plant extracts mitigate the effects of excitotoxicity and oxidative damage in hippocampus and this might be accomplished by their antioxidative properties.

Effect of dimethyl diphenyl bicarboxylate on normal and chemically-injured liver

This study evaluates the effect of DDB on normal and chemically-injured liver. When given to normal rats DDB had no significant effect on liver enzymes, but in chemically-injured rats there was a significant decrease in the elevated levels of liver enzymes. DDB produced a significant increase in reduced glutathione, glutathione peroxidase and glutathione reductase, and a significant decrease in malondialdehyde and glucose-6-phosphate dehydrogenase in both normal and chemically-injured liver. The histopathology examinations showed a slight improvement with DDB administration. DDB has a beneficial effect on liver enzymes and possesses significant antioxidant properties in normal and chemically-injured liver, and may therefore be clinically useful in treating chronic viral hepatitis B in humans

Effects of exogenous vitamin C on ethanol toxicity in rats.

The effect of a mega dose of ascorbic acid (200 mg/100 g body wt.) on alcohol-induced toxicity in rats was evaluated. In rats administered alcohol and ascorbic acid, malondialdehyde (MDA), hydroperoxide and conjugated dienes decreased in comparison with that given alcohol alone. The reduced activities of scavenging enzymes, e.g. superoxide dismutase (SOD) and catalase, in ethanol-administered rats were also enhanced by the co-administration of ascorbic acid and ethanol. Co-administration of ethanol and ascorbic acid reduced phospholipids and MDA levels of the erythrocyte membrane in comparison with that of the ethanol fed rats. The reduction in the activities of glutamic oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT), gamaglutamyl transpeptidase (GGT) and the decrease in triglycerides levels also clearly showed the protective action of ascorbic acid in reducing ethanol induced toxicity.

Haemolytic potential of three chemotherapeutic agents and aspirin in glucose-6-phosphate dehydrogenase deficiency

The potential haemolytic effect of three chemotherapeutic drugs and aspirin was tested in vitro by gluthathione stability tests. Blood was collected from the local population of Basra, Iraq where previous studies had found a high frequency of glucose-6-phosphate dehydrogenase [G6PD] deficiency. Primaquine, chloramphenicol and sulfanilamide caused significant concentration-dependent reductions of glutathione levels in G6PD-deficient red cells when compared to normal red cells. Acetylsalicylic acid had no effect on glutathione level. The G6PD-deficient erythrocytes behaved as previously reported, probably due to similar patterns in the distribution of its variants. Studies on each local variant are warranted and new drugs should be tested for haemolytic potential prior to their introduction in areas where the deficiency is common