Protection against liver ischemia-reperfusion injury in rats by silymarin or verapamil

A review on the mechanisms of the effect of silymarin in milk thistle (Silybum marianum) on some laboratory animals

One of the most valuable medicinal plants is milk thistle (Silybum marianum) or martighal. An annual or biennial plant of the Asteraceae family and English name Milk thistle, a Matte green colour and prickly plant with a standing stem that can be thick, simple, or slightly branched (ramified). Its seeds contain about 70%-80% of the flavonolignans of silymarin and about 20%-30% of polymeric and oxidized polyphenolic compounds (such as tannins). Traditionally, the plant has been used to increase milk secretion, relieve menstrual cramps, lessen depression, decrease gallstones, and jaundice as well as improve functions of the liver, spleen, and kidney. This review reviews studies on the effects of adding milk thistle to quail diet. Consumption (0.5% and 1%) of milk thistle powder in the diet of Japanese quail significantly increased feed intake, body weight, and improved carcass components. Blood constituents including total protein and albumin were improved along with decreased HDL, ALT, and AST. The use of milk thistle levels (0.5% and 1.5%) significantly improved the antioxidant total of plasma. Consumption of silymarin in quail diet increased the number of white blood cells, calcium, vitamin D3, and albumin. Silymarin also decreased the relative weights of bursa of Fabricius and spleen. This review indicates that milk thistle can improve growth performance, feed conversion ratio, and immune system in quail.

The decrease of lasalocid residue in the edible tissues by silymarin supplementation of chicken diet

Widespread use of coccidiostats, in spite of beneficial control of protozoan infections in poultry, implies a risk of residues in edible tissues, and there is increasing interest in the development of strategies for prevention of veterinary drugs residue in food-producing animals. The aim of this study is assigned to clarify the impact of silymarin addendum in the diet on lasalocid concentration in the liver and breast muscles from the broiler. Four groups of chickens received a feed with lasalocid at levels between 75 and 200 mg kg^-1. Other four groups received a feed with lasalocid (75-200 mg kg^-1) plus silymarin. Significant differences of lasalocid concentrations between the liver and breast muscles were observed. Moreover, the chickens from the groups supplemented with silymarin shown significant decreases of lasalocid concentrations in the analysed tissues. The herbal substance did not counteract the ionophore in the treatment of coccidiosis and did not change biochemical parameters of blood. These findings suggest that silymarin might be used in chicken feeding in order to reduce the risk from lasalocid contamination of the broiler edible tissues.

Evaluating the protective efficacy of Silybum marianum against deltamethrin induced hepatotoxicity in piscine model

With the known facts of deltamethrin toxicity in aquaculture, efforts have been made to ameliorate its toxicity with supplementation of Silybum marianum plant extract in Cyprinus carpio. For validating its efficacy, standard techniques of histopathology, anti-oxidant profile and RAPD-PCR were used. By performing acute toxicity bioassay, 96 h LC50 of the pesticide to C. carpio was determined and was found to be 2 μg/L. Histopathological alterations were comprised of nuclear alterations, vacuolisation and oedema in the hepatocytes. Chronic exposure to the toxicant induced significant changes in antioxidant defense system (CAT, SOD, GSH and GST levels), lipid peroxidation being prominent. Diet supplementation with silymarin appeared to modulate the oxidative stress, histopathological alterations and genotoxic damage caused by the pesticide in the fish. RAPD-PCR studies revealed deltamethrin induced toxicity and its effective amelioration in form of restoration of bands which were lost in toxicant exposed DNA profile.

Silybum marianum provides cardioprotection and limits adverse remodeling post-myocardial infarction by mitigating oxidative stress and reactive fibrosis

AIMS

Milk thistle (Silybum marianum; SM) is an herb commonly used for hepatoprotection with antioxidant and antifibrotic properties. We investigated in pigs the cardiac effects of SM intake during the acute phase of myocardial infarction (MI) and remodeling period post-MI.

METHODS

Study-1 tested the effect of SM use on the acute phase of MI. Hence, animals were distributed to a control group or to receive SM prior infarction (1.5 h ischemia). Animals were sacrificed after 2.5 h of reperfusion. Study-2 tested the effect of SM use in the cardiac remodeling phase. Accordingly, animals received for 10 d diet ± SM prior MI and followed the same regime for 3 weeks and then sacrificed. Study-3 tested the effect of SM in a non-infarcted heart; therefore, animals received for 10 d diet ± SM and then sacrificed.

RESULTS

Animals taking SM before MI showed a reduction in cardiac damage (decreased oxidative damage, ROS production and xanthine oxidase levels; preserved mitochondrial function; and increased myocardial salvage; p < 0.05) versus controls. Animals that remained on chronic SM intake post-MI improved left ventricular remodeling. This was associated with the attenuation of the TGFß1/TßRs/SMAD2/3 signaling, lower myofibroblast transdifferentiation and collagen content in the border zone (p < 0.05 vs. all other groups). Cardiac contractility improved in animals taking SM (p < 0.05 vs. post-MI-control). No changes in cardiac function or fibrosis were detected in animals on SM but without MI.

CONCLUSION

Intake of SM protects the heart against the deleterious effects of an MI and favors cardiac healing. These benefits may be attributed to the antioxidant and antifibrotic properties of SM.

Neurotoxicity, behavioral changes and gene-expression profile of mice exposed to SnS2 nanoflowers

Recently, interest in the potential applications of tin disulphide nanoflowers (SnS2 NFs) in the treatment of waste water and their antibacterial properties has increased. However, their effects on neurotoxicity, brain cognition and behavioural injury, as well as the underlying mechanisms of these effects have remained unknown. In the present study, we compared the neurotoxicity of SnS2 NFs (50 nm) administered intragastrically at different doses (5, 10, and 50 mg kg-1) in mice for 60 days. The results showed that the neurotoxicity of SnS2 NFs in mice is dose-dependent. Furthermore, expression levels of genes related to oxidative stress, metabolism and signal transduction were also modified in the brain tissues of mice exposed to SnS2 NFs, supporting the SnS2 NF-dependent neurotoxic phenotype. Additionally, SnS2 NF exposure resulted in an abnormal ultrastructure in the hippocampus of the treated mice. Nevertheless, their body weight, organ coefficient and behaviour assessed in an open-field test and learning and memory test results assessed using a Morris water maze test remained unaffected. This suggested that the increased risk of neurotoxicity in SnS2 NF-treated mice was dependent on the dosage of SnS2 NFs. The relative level of safety was <5 mg kg-1 for 50 nm SnS2 NFs. The present study provides an experimental basis for the safe application of SnS2 NFs; however, chronic behavioural effects of SnS2 NFs remain unknown.

Protective Effects of Silymarin Against Age-Related Hearing Loss in an Aging Rat Model

Age-related hearing loss (ARHL) is one of the most common chronic degenerative disorders. Several studies have indicated that supplementation with some antioxidants can slow down the progression of ARHL. Despite several lines of evidence about the potent antioxidant and anti-aging effects of silymarin, its protective effect against ARHL has not evaluated yet. The aim of the current study was to investigate the effects of silymarin in prevention of ARHL in a d-Galactose-induced aging rat model for the first time. 45 male wistar rats aged 3-month old were divided into 5 groups: group 1, 2 and 3 received 500 mg/kg/day d-Gal plus 100, 200 and 300 mg/kg/day silymarin respectively for 8 weeks, placebo group received 500 mg/kg/day d-Gal plus propylene glycol as placebo, and control group received normal saline during this period of time. Auditory brainstem responses were measured at several frequencies (4, 6, 8, 12 and 16 kHz) before and after the intervention. Placebo group and group 3 showed significant ABR threshold increase across frequencies of 4, 6, 16 kHz compared with the other groups (P < 0.05). However, rats treated with silymarin 100 and 200 mg/kg/day plus d-Gal did not show any significant ABR threshold shifts. Similarly, ABR amplitude of P2 at 4, 8 kHz and P1, P4 at 4 kHz in the placebo group and group 3 were decreased significantly compared with other groups (P < 0.05). However, no significant differences are found in ABR absolute and inter-peak latencies between groups (P > 0.05). The findings indicates that silymarin with doses of 100 and 200 mg/kg/day has protective effect against ARHL and it can be supplemented into the diet of older people to slow down the progression of age-related hearing loss.

Neuroprotective effects of silymarin on ischemia-induced delayed neuronal cell death in rat hippocampus

We examined the effects of silymarin, which was extracted from Silybum marianum, on delayed neuronal cell death in the rat hippocampus. Rats were divided into four groups: sham-operated rats (sham group), rats which underwent ischemic surgery (control group), rats which were treated with silymarin before and after ischemic surgery (pre group), and rats which were treated with silymarin after ischemic surgery only (post group). We performed the ischemic surgery by occluding the bilateral carotid arteries for 20min and sacrificed the rats one week after the surgery. Silymarin was administered orally at 200mg/kg body weight. Smaller numbers of delayed cell deaths were noted in the rat CA1 region of the pre- and post-groups, and no significant difference was observed between these groups. There were few apoptotic cell deaths in all groups. Compared to the control group, significantly fewer cell deaths by autophagy were found in the pre- and post-group. We concluded that silymarin exerts a preservation effect on delayed neuronal cell death in the rat hippocampus and this effect has nothing to do with the timing of administering of silymarin.

Phoxim-induced damages of Bombyx mori larval midgut and titanium dioxide nanoparticles protective role under phoxim-induced toxicity

Phoxim (O,O-diethyl O-(alpha-cyanobenzylideneamino) phosphorothioate) is a powerful organophosphorus pesticide with high potential for Bombyx mori larvae of silkworm exposure. However, it is possible that during the phoxim metabolism, there is generation of reactive oxygen species (ROS) and phoxim may produce oxidative stress and neurotoxicity in an intoxicated silkworm. Titanium dioxide nanoparticles (TiO2 NPs) pretreatment has been demonstrated to increase antioxidant capacity and acetylcholinesterase (AChE) activity in organisms. This study was, therefore, undertaken to determine phoxim-induced oxidative stress and neurotoxicity to determine whether phoxim intoxication alters the antioxidant system and AChE activity in the B. mori larval midgut, and to determine whether TiO2 NPs pretreatment attenuates phoxim-induced toxicity. The findings suggested that phoxim exposure decreased survival of B. mori larvae, increased malondialdehyde (MDA), carbonyl and 8-OHdG levels, and ROS accumulation in the midgut. Furthermore, phoxim significantly decreased the activities of AChE, superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione-S-transferase (GST), and levels of ascorbic acid (AsA), reduced glutathione (GSH), and thiol in the midgut. TiO2 pretreatment, however, could increase AChE activity, and remove ROS via activating SOD, CAT, APX, GR, and GST, and accelerating AsA-GSH cycle, thus attenuated lipid, protein, and DNA peroxidation and improve B. mori larval survival under phoxim-induced toxicity. Moreover, this experimental system would help nanomaterials to be applied in the sericulture.

Silymarin alleviates bleomycin-induced pulmonary toxicity and lipid peroxidation in mice

CONTEXT

The application of bleomycin is limited due to its side effects including lung toxicity. Silymarin is a flavonoid complex isolated from milk thistle [Silybum marianum L. (Asteraceae)] which has been identified as an antioxidant and anti-inflammatory compound.

OBJECTIVE

This study evaluates the effect of silymarin on oxidative and inflammatory parameters in the lungs of mice exposed to bleomycin.

MATERIALS AND METHODS

BALB/c mice were divided into four groups of control, bleomycin (1.5 U/kg), bleomycin plus silymarin (50 and 100 mg/kg). After bleomycin administration, mice received 10 d intraperitoneal silymarin treatment. On 10th day, blood and lung samples were collected for measurement of oxidative and inflammatory factors.

RESULTS

Silymarin led to a decrease in lung lipid peroxidation (0.19 and 0.17 nmol/mg protein) in bleomycin-injected animals. Glutathione-S-transferase (GST) which was inhibited by bleomycin (32.4 nmol/min/mg protein) induced by higher dose of silymarin (41 nmol/min/mg protein). Silymarin caused an elevation in glutathione (GSH): 2.6 and 3.1 µmol/g lung compare with bleomycin-injected animals 1.8 µmol/g lung. Catalase (CAT) was increased due to high dose of silymarin (65.7 µmol/min/ml protein) compare with bleomycin treated-mice. Myeloperoxidase (MPO) which was induced due to bleomycin (p < 0.05) reduced again by high dose of silymarin (0.51 U/min/mg protein). Bleomycin led to an increase in TNF-α and interleukin-6 (IL-6) (7.9 and 11.8 pg/ml). These parameters were reduced by silymarin (p < 0.05).

CONCLUSIONS

Silymarin attenuated bleomycin induced-pulmonary toxicity. This protective effect may be due to the ability of silymarin in keeping oxidant-antioxidant balance and regulating of inflammatory mediator release.

Renal injury and Nrf2 modulation in mouse kidney following chronic exposure to TiO₂ nanoparticles

TiO₂ nanoparticles (NPs) are used in the food industry but have potential toxic effects in humans and animals. TiO₂ NPs impair renal function and cause oxidative stress and renal inflammation in mice, associated with inhibition of nuclear factor erythroid-2-related factor 2 (Nrf2), which regulates genes encoding many antioxidants and detoxifying enzymes. This study determined whether TiO₂ NPs activated the Nrf2 signaling pathway. Mice exhibited accumulation of reactive oxygen species and peroxidation of lipid, protein, and DNA in the kidney, coupled with renal dysfunction, glutathione depletion, inflammatory cell infiltration, fatty degeneration, and apoptosis. These were associated with increased expression of NOX4, cyclooxygenase-2, and nuclear factor-κB. Oxidative stress and inflammation were accompanied by decreased expression of Nrf2 and down-regulation of its target gene products including heme oxygenase 1, glutamate-cysteine ligase catalytic subunit, and glutathione S-transferase. Chronic TiO₂ NP exposure is associated with suppression of Nrf2, which contributes to the pathogenesis of oxidative stress and inflammation.

Toxicological mechanisms of nanosized titanium dioxide-induced spleen injury in mice after repeated peroral application

Due to an increase in surface area per particle weight, nanosized titanium dioxide (nano-TiO2) has greatly increased its function as a catalyst and is used for whitening and brightening foods. However, concerns over the safety of nano-TiO2 have been raised. The purpose of this study was to determine whether the protein kinase MAPKs/PI3-K/Akt signaling pathways and transcription factors are activated prior to or concurrent with COX-2 up-regulation in mouse spleen following exposure to 10 mg/kg BW of pure anatase nano-TiO2 by the intragastric route for 15-90 days. The study clearly showed that nano-TiO2 was deposited in the spleen and resulted in reactive oxygen species production, time-dependent splenic inflammation, and necrosis, coupled with a 12.64-64.06% increase in COX-2 and prostaglandin E2 expression, respectively. Furthermore, nano-TiO2 elevated the expressions of ERK, AP-1, CRE, Akt, JNK2, MAPKs, PI3-K, c-Jun, and c-Fos in the spleen by 1.08-6-fold with increased exposure duration, respectively. These findings suggested that nano-TiO2-induced COX-2 expression may be mediated predominantly through the induction of AP-1 and CRE and that AP-1/CRE induction occurred via the MAPKs/PI3-K/Akt signaling pathways in the spleen. Therefore, the findings suggest the need for caution when using nanomaterials as food additives.

Cardiac oxidative damage in mice following exposure to nanoparticulate titanium dioxide

Nanoparticulate titanium dioxide (nano-TiO2 ) is a widely used powerful nanoparticulate material with high stability, anticorrosion, and photocatalytic property. However, it is possible that during nano-TiO2 exposure, there may be negative effects on cardiovascular system in intoxicated mice. The present study was therefore undertaken to determine nano-TiO2 -induced oxidative stress and to determine whether nano-TiO2 intoxication alters the antioxidant system in the mouse heart exposed to 2.5, 5, and 10 mg/kg body weight nano-TiO2 for 90 consecutive days. The findings showed that long-term exposure to nano-TiO2 resulted in obvious titanium accumulation in heart, in turn led to sparse cardiac muscle fibers, inflammatory response, cell necrosis, and cardiac biochemical dysfunction. Nano-TiO2 exposure promoted remarkably reactive oxygen species production such as superoxide radicals, hydrogen peroxide, and increased malondialdehyde, carbonyl and 8-OHdG levels as degradation products of lipid, protein, and DNA peroxidation in heart. Furthermore, nano-TiO2 exposure attenuated the activities of antioxidative enzymes, such as superoxide dismutase, ascorbate peroxidase, glutathione reductase, glutathione-S-transferase, and levels of antioxidants including ascorbic acid, glutathione, and thiol in heart. Therefore, TiO2 NPs exposure may impair cardiovascular system in mice, and attention should be aroused on the application of nano-TiO2 and their potential long-term exposure effects especially on human beings.

Intragastric exposure to titanium dioxide nanoparticles induced nephrotoxicity in mice, assessed by physiological and gene expression modifications

Background

Numerous studies have demonstrated that titanium dioxide nanoparticles (TiO₂ NPs) induced nephrotoxicity in animals. However, the nephrotoxic multiple molecular mechanisms are not clearly understood.

Methods

Mice were exposed to 2.5, 5 and 10 mg/kg TiO₂ NPs by intragastric administration for 90 consecutive days, and their growth, element distribution, and oxidative stress in kidney as well as kidney gene expression profile were investigated using whole-genome microarray analysis technique.

Results

Our findings suggest that TiO₂ NPs resulted in significant reduction of renal glomerulus number, apoptosis, infiltration of inflammatory cells, tissue necrosis or disorganization of renal tubules, coupled with decreased body weight, increased kidney indices, unbalance of element distribution, production of reactive oxygen species and peroxidation of lipid, protein and DNA in mouse kidney tissue. Furthermore, microarray analysis showed significant alterations in the expression of 1, 246 genes in the 10 mg/kg TiO₂ NPs-exposed kidney. Of the genes altered, 1006 genes were associated with immune/inflammatory responses, apoptosis, biological processes, oxidative stress, ion transport, metabolic processes, the cell cycle, signal transduction, cell component, transcription, translation and cell differentiation, respectively. Specifically, the vital up-regulation of Bcl6, Cfi and Cfd caused immune/ inflammatory responses, the significant alterations of Axud1, Cyp4a12a, Cyp4a12b, Cyp4a14, and Cyp2d9 expression resulted in severe oxidative stress, and great suppression of Birc5, Crap2, and Tfrc expression led to renal cell apoptosis.

Conclusions

Axud1, Bcl6, Cf1, Cfd, Cyp4a12a, Cyp4a12b, Cyp2d9, Birc5, Crap2, and Tfrc may be potential biomarkers of kidney toxicity caused by TiO₂ NPs exposure.

Signal pathway of hippocampal apoptosis and cognitive impairment of mice caused by cerium chloride

Experimental studies have demonstrated that lanthanides could impair cognitive functions of children and animals, but very little is known about the hippocampal apoptosis and its molecular mechanism. The study investigated the signal pathway of hippocampal apoptosis induced by intragastric administration of CeCl(3) for 60 consecutive days. It showed that cerium had been significantly accumulated in the mouse hippocampus, and CeCl(3) caused hippocampal apoptosis and impairment of spatial recognition memory of mice. CeCl(3) effectively activated caspase-3 and -9, inhibited Bcl-2, and increased the levels of Bax and cytochrome c, promoted accumulation of reactive oxygen species in the mouse hippocampus. It implied that CeCl(3)-induced apoptosis in the mouse hippocampus could be triggered via mitochondrion-mediated pathway. Our findings suggest the need for great caution to handle the lanthanides for workers and consumers.

Pulmotoxicological effects caused by long-term titanium dioxide nanoparticles exposure in mice

Exposure to titanium dioxide nanoparticles (TiO(2) NPs) has been demonstrated to result in pulmonary inflammation in animals; however, very little is known about the molecular mechanisms of pulmonary injury due to TiO(2) NPs exposure. The aim of this study was to evaluate the oxidative stress and molecular mechanism associated with pulmonary inflammation in chronic lung toxicity caused by the intratracheal instillation of TiO(2) NPs for 90 consecutive days in mice. Our findings suggest that TiO(2) NPs are significantly accumulated in the lung, leading to an obvious increase in lung indices, inflammation and bleeding in the lung. Exposure to TiO(2) NPs significantly increased the accumulation of reactive oxygen species and the level of lipid peroxidation, and decreased antioxidant capacity in the lung. Furthermore, TiO(2) NPs exposure activated nuclear factor-κB, increased the levels of tumor necrosis factor-α, cyclooxygenase-2, heme oxygenase-1, interleukin-2, interleukin-4, interleukin-6, interleukin-8, interleukin-10, interleukin-18, interleukin-1β, and CYP1A1 expression. However, TiO(2) NPs exposure decreased NF-κB-inhibiting factor and heat shock protein 70 expression. Our results suggest that the generation of pulmonary inflammation caused by TiO(2) NPs in mice is closely related to oxidative stress and the expression of inflammatory cytokines.

Effect of silymarin on bladder overactivity in cyclophosphamide-induced cystitis rat model

The purpose of this study was to investigate the effects of silymarin, a phytotherapeutic agent, on bladder overactivity in a cyclophosphamide (CYP)-induced cystitis rat model. Female Wistar Albino rats received a single intraperitoneal injection of CYP (150 mg/kg) or saline and after 72 h, bladder function was evaluated by in vitro preparations of whole bladders and cystometry with continuous saline infusion under urethane anesthesia. Silymarin or a vehicle was orally given for 7 days in rats. CYP was injected on the 5th day of silymarin or vehicle treatment and then the animals were killed on the 8th day. CYP-treatment dramatically potentiated the basal spontaneous contractions of isolated whole bladders compared to control rats. In anesthetized rats, during continuous infusion cystometry, intercontraction interval (ICI) was significantly shorter, but bladder voiding pressure was not significantly changed in CYP-injected rats compared to control rats. In the CYP-injected group, silymarin treatment significantly decreased the amplitude, frequency (contractions/min) and area under the curve of spontaneous contractions, but failed to change carbachol-induced contraction in isolated whole bladder. Also, silymarin treatment significantly increased the ICI in comparison to the vehicle treatment. In the saline-injected group, no significant changes in the bladder function were observed between the silymarin and vehicle-treated groups. Histopathological examination showed that CYP-induced bladder inflammation tended to be lower in the silymarin+CYP-treated group. In conclusion, the oral administration of silymarin suppressed CYP-induced bladder overactivity. Silymarin may be considered as an attractive treatment for CYP-induced bladder overactivity.

Liver injury and its molecular mechanisms in mice caused by exposure to cerium chloride

Cerium has been demonstrated to damage liver of mice, but very little is known about the molecular mechanisms underlying the mouse liver apoptosis. In order to understand the liver injury induced by intragastric administration of cerium chloride (CeCl3) for 60 consecutive days, the hepatocyte ultrasrtucture, various oxidative stress parameters, and the stress-related gene expression levels were investigated for the mouse liver. The results demonstrated that CeCl3 had an obvious accumulation in the mouse liver, leading to a classical laddering cleavage of DNA and hepatocyte apoptosis. CeCl3 significantly promoted the accumulation of reactive oxygen species and inhibited the stress-related gene expression of superoxide dismutase, catalase, glutathione peroxidase, metallothionein, heat-shock protein 70, glutathione-S-transferase, P53, and transferring, and it effectively activated the cytochrome p450 1A. It implied that CeCl3 resulted in apoptosis and alteration of expression levels of the genes related with metal detoxification/metabolism regulation and radical scavenging action in mice.

Effects of long-term silymarin oral supplementation on the blood biochemical profile of rainbow trout (Oncorhynchus mykiss)

Silymarin, an extract from "milk thistle" (Silybum marianum) plant is traditionally used as herbal medicine. The present study was conducted to investigate the clinical effects and possible side effects of silymarin on biochemical blood parameters of rainbow trout (Oncorhynchus mykiss). Fishes were treated with 0 (control), 100, 400, and 800 mg of silymarin per kg of food during 4 weeks. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), creatine kinase (CK), glucose, total protein, creatinine, triglyceride, cholesterol, urea, uric acid and liver cellular total antioxidant, and protein content were measured after 7, 14, and 28 days of silymarin treatment. The results showed that oral administration of silymarin in fish significantly reduced plasma glucose and cholesterol levels and relatively increased plasma total protein and globulin concentrations (P < 0.05). Increasing plasma albumin levels indicate the important role of albumin in drug transportation in circulatory system of fish. Silymarin also stabilized cellular membrane structure and regulated the levels of AST, ALT, ALP, CK, and LDH activity. In conclusion, on the basis of these results, oral administration of silymarin up to 400 mg per 1 kg of food has no side effect on blood biochemical and clinical parameters of fishes. However, oral administration of 800 mg/kg- of silymarin caused cytotoxicity and modifications in blood biochemical parameters of fish.

Oxidative injury in the brain of mice caused by lanthanid

The organ toxicity of lanthanides (Ln) on organisms had been recognized, but very little is known about the oxidative injury of brain caused by Ln. In order to study the mechanisms underlying the effects of Ln on the brain, ICR mice were injected with a single 20 mg/kg body weight dose of LaCl(3), CeCl(3), and NdCl(3) into the abdominal cavity daily for 14 days. We then examined the coefficient of the brain, the brain pathological changes and oxidative stress-mediated responses, and the accumulation of Ln and levels of neurochemicals in the brain. The results showed that CeCl(3) and NdCl(3) could induce some neurons to turn inflammatory cells and slight edema but did not observe the brain pathological changes from LaCl(3)-treated group. The concentrations of La, Ce, and Nd in the brain were significantly different and ranked in the order of Ce, Nd, and La. The injury of the brain and oxidative stress occurred as Ln appeared to trigger a cascade of reactions such as lipid peroxidation, the decreases of the total antioxidation capacity and activities of antioxidative enzymes, the excessive release of nitric oxide, the increase of glutamic acid, and the downregulated level of acetylcholinesterase activities. Furthermore, both Ce(3+) and Nd(3+) exhibited higher oxidative stress and toxicity on brain than La(3+), and Ce(3+) caused more severe brain injuries and oxidative stress than Nd(3+), implying that the differences in the brain injuries caused by Ln might be related to the number of 4f electrons of Ln.

Molecular mechanism of hippocampal apoptosis of mice following exposure to titanium dioxide nanoparticles

Previous studies demonstrate that the exposure to titanium dioxide nanoparticles (TiO(2) NPs) damages the central nervous system of mice; however, very little is known about the effects of TiO(2) NPs on hippocampal apoptosis or its molecular mechanism. The present study investigated the molecular mechanism associated with hippocampal apoptosis in mice induced by intragastric administration of TiO(2) NPs for consecutive 60 days. Our findings indicate that TiO(2) NPs accumulate in the mouse hippocampus, and this accumulation, in turn, led to hippocampal apoptosis and impairment in spatial recognition memory in mice. In addition, TiO(2) NPs significantly activated caspase-3 and -9, inhibited Bcl-2, and promoted the levels of Bax and cytochrome c. Furthermore, TiO(2) NPs induced accumulation of reactive oxygen species in the mouse hippocampus. These findings suggest that TiO(2) NP-induced apoptosis in the mouse hippocampus may result from an intrinsic pathway, and workers and consumers should take great caution when handling nanomaterials.

P38-Nrf-2 signaling pathway of oxidative stress in mice caused by nanoparticulate TiO2

Some recent studies have been previously suggested that nanoparticulate titanium dioxide (TiO(2)) damaged liver function and decreased immunity of mice, but the spleen injury and its oxidative stress mechanism are still unclear. To understand the spleen injury induced by intragastric administration of nanoparticulate anatase TiO(2) for consecutive 30 days, the spleen pathological changes, the oxidative stress, and p38 and c-Jun N-terminal kinase signaling pathways, along with nuclear factor-κB and nuclear factor-E2-related factor-2 (Nrf-2), were investigated as the upstream events of oxidative stress in the mouse spleen from exposure to nanoparticulate TiO(2). The results suggested that nanoparticulate TiO(2) caused congestion and lymph nodule proliferation of spleen tissue, which might exert its toxicity through oxidative stress, as it caused significant increases in the mouse spleen reactive oxygen species accumulations, subsequently leading to the strong lipid peroxidation and the significant expression of heme oxygenase-1 via the p38-Nrf-2 signaling pathway. The studies on the mechanism by which nanoparticulate TiO(2) induced the p38-Nrf-2 signaling pathway are helpful to a better understanding of the nanoparticulate TiO(2)-induced oxidative stress and reduction of immune capacity.

Splenocyte apoptotic pathway in mice following oral exposure to cerium trichloride

With their widespread application in agriculture, industry, culture, medicine, and daily life, lanthanide compounds are being brought into the ecological environment and human body through food chains. It is important to know the acute and chronic effects of lanthanides on the environment, nature balance, and the human body after their entry into bodies and the environment. Lanthanides have been demonstrated to cause spleen apoptosis and decreased immunity of mice, but very little is known about the molecular aspects of these mechanism. In order to understand the spleen apoptotic mechanism induced by intragastric administration of 2, 10 and 20 mg kg(-1) body weight CeCl(3) for consecutive 60 d, we investigated the cerium accumulation, apoptosis, the expression levels of the apoptosis-related cytokines into apoptosis-related genes and proteins. The results demonstrated that cerium had obvious accumulation in the mouse spleen, leading to the significant increase of the spleen indices and splenocyte apoptosis. Furthermore, CeCl(3) could effectively activate caspase-3 and -9, decrease the Bcl-2 the levels of gene and protein, and increase the levels of Bax, and cytochrome c genes and their protein expressions, and promote reactive oxygen species production. It implied CeCl(3)-induced apoptosis in the mouse spleen via intrinsic pathway. Our findings suggest the need for great caution to handle the lanthanides for workers and consumers.

Oxidative stress in the liver of mice caused by intraperitoneal injection with lanthanoides

In order to study the mechanisms underlying the effects of lanthanoid (Ln) on the liver, ICR mice were injected with LaCl₃, CeCl₃, and NdCl₃ at a dose of 20 mg/kg BW into the abdominal cavity daily for 14 days. We then examined oxidative stress-mediated responses in the liver. The increase of lipid peroxide in the liver produced by Ln suggested an oxidative attack that was activated by a reduction of antioxidative defense mechanisms as measured by analyzing the activities of superoxide dismutase, catalase, and ascorbate peroxidase, as well as antioxidant levels such as glutathione and ascorbic acid, which were greatest in Ce(3+) treatment, medium in Nd(3+), and least in La(3+). Our results also implied that the oxidative stress in the liver caused by Ln likely is Ce(3+) > Nd(3+) >La(3+), but the mechanisms need to be further studied in future.

Hepatocyte apoptosis and its molecular mechanisms in mice caused by titanium dioxide nanoparticles

While the hepatocyte apoptosis induced by TiO(2) nanoparticles (NPs) has been demonstrated, very little is known about the molecular mechanisms underlying this mouse liver apoptosis. In order to understand the hepatocyte apoptosis induced by intragastric administration of TiO(2) NPs for consecutive 60 days, the hepatocyte apoptosis, various oxidative stress parameters and the stress-related gene expression levels were assayed for the mouse liver. 60 days of TiO(2) NPs exposure, hepatocyte apoptosis in the liver could be observed, which was followed by increased reactive oxygen species accumulation, and decreased the stress-related gene expression levels of superoxide dismutase, catalase, glutathione peroxidase, metallothionein, heat shock protein 70, glutathione S transferase, P53, and transferrin; and the significant enhancement of the cytochrome p450 1A expression level. It implied that hepatocyte apoptosis, oxidative stresses, and alteration of expression levels of the genes related with TiO(2) NPs detoxification/metabolism regulation and radical scavenging action. Therefore, the application of TiO(2) NPs and exposure effects especially on human liver for long-term and low-dose treatment should be cautious.

Antioxidative role of cerium against the toxicity of lead in the liver of silver crucian carp

The antioxidative role of cerium was investigated in the liver of silver crucian carp injected with lead. The fish were intraperitoneally injected with 10, 20, or 30 mg/kg wet weight PbCl(2). After a 14-day period of incubation, 35 animals were injected with a solution of 1.5 mg/kg wet weight CeCl(3). After 42 days, the wet weight and the liver weight of the fish were weighed, and the oxidative stress of the fish liver was estimated by assaying lipid peroxide, superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, glutathione, ascorbic acid, and reactive oxygen species (ROS). The results show that Ce(3+) could decrease ROS accumulation, relieve the inhibition of the activities of the antioxidant enzyme and the reduction of antioxidants in fish liver caused by Pb(2+), and decrease the enhancement of hepatosomatic index of fish under various Pb(2+) dosages.

Comparison of the prophylactic effect of silymarin and deferoxamine on iron overload-induced hepatotoxicity in rat

In pathologic conditions or poisoning states, iron overload can affect different tissues including liver. In this study, the prophylactic effect of deferoxamine and silymarin was compared in decreasing experimental iron-overload-induced hepatotoxicity in rats. The study was done in six groups of rats, which received drugs q2 days for 2 weeks. The rats in groups 1 to 6 received drugs, respectively: normal saline, iron dextran, iron dextran + deferoxamine (intraperitoneally), iron dextran + silymarin (orally), iron dextran + silymarin (intraperitoneally), and iron dextran + deferoxamine (intraperitoneally) + silymarin (intraperitoneally). At the end of the study, blood was collected, and serum was separated for laboratory tests. The liver of rats was separated for iron measuring and tissue processing. The serum iron concentration and the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity were determined. The numbers of necrotic hepatocytes were counted as quantity index tissue injury in light microscopic examination. The mean of serum and liver iron in group 2 was significantly greater than group 1. Liver iron was significantly decreased in other groups except group 4. Also serum iron was decreased in groups 3 to 6 compared to group 2 (nearly 400%). ALT activity in group 3 and AST activity in group 5 were significantly lesser than in other groups. The mean of necrotic hepatocytes in group 2 was significantly increased in comparison to group 1. This elevation was significantly prevented by deferoxamine and silymarin. The result of the present study shows that silymarin has a protective effect similar to deferoxamine on iron overload-induced hepatotoxicity.

The oxidative damage in lung of mice caused by lanthanoide

This study was performed with the objective of assessing the antioxidant response of the lung of mice to different rare earths. LaCl(3), CeCl(3), and NdCl(3) at a higher dose of 20 mg/kg body weight were injected into the nasal cavity of ICR mice for consecutive 14 days, respectively. The increase of pulmonary lipids peroxide produced by Ln suggested an oxidative attack that was activated by a reduction of antioxidative defense mechanisms as measured by analyzing the activities of superoxide dismutase, catalase, ascorbate peroxidase, and total antioxidant capacity, as well as antioxidant levels such as glutathione and ascorbic acid, which were greatest in Ce(3+) treatment, medium in Nd(3+), and least in La(3+). It implied that the antioxidative responses of lung may be involved in 4f shell and alternable valence properties of Ln-induced lung toxicity.

Antioxidant and protective effects of silymarin on ischemia and reperfusion injury in the kidney tissues of rats

BACKGROUND

Renal ischemia/reperfusion (I/R) injury is a major cause of acute renal failure. Silymarin is extracted from Silybum marianum and Cynara cardunculus seeds and fruits. The aim of this study is to investigate whether silymarin administration prevents the damage induced by I/R in rat kidneys.

MATERIALS AND METHODS

Thirty male Wistar rats were randomly divided into five experimental groups (n = 6, each) as follows; control group, sham-operated group, I/R group, silymarin group, and I/R + silymarin group. In the I/R and I/R + silymarin groups, both renal arteries were occluded using nontraumatic microvascular clamps for 45 min. Then, at the end of 24 h of reperfusion, the animals were killed. Kidney function tests, the serum and tissue antioxidant enzymes and oxidant products were determined.

RESULTS

Animals that were subjected to I/R exhibited significant increase in serum urea, creatinine, and cystatin C levels compared with the rats treated with silymarin prior to the I/R process (P < 0.001). The serum enzymatic activities of superoxide dismutase and glutathione peroxidase significantly decreased in the I/R group; however, this reduction was significantly improved by the treatment with silymarin (P < 0.001 and P < 0.05, respectively). Renal I/R produced a significant increase in serum and tissue malondialdehyde, nitric oxide, and protein carbonyl as compared with controls. Treatment with silymarin resulted in significant reduction in these markers (P < 0.001).

CONCLUSION

Based on our findings, silymarin protects the kidneys against I/R injury. This finding may provide a basis for the development of novel therapeutic strategies for protection against the damages caused by I/R.

Effects of carvacrol on defects of ischemia-reperfusion in the rat liver

Many plants found in nature have been used to treat various illnesses. One such plant is oregano (Kekik in Turkish). Health beneficial effects of carvacrol obtained from oregano oil have been shown scientifically. We have investigated the comparative effects of carvacrol in the liver of rats subjected to ischemia-reperfusion defect, with silymarin. To test the effects we formed four groups using male Wistar albino rats. Group I was control. The other three groups of animals were administered 60min prior to surgical operation single doses of physiological serum, carvacrol and silymarin, respectively. Group II, III and IV animal were subjected to 45min long liver ischemia and 60min reperfusion. Blood and tissue samples were collected for biochemical and histological analysis following the test. AST and ALT values obtained after biochemical analysis of the serums showed statistically significant difference in group II than the other three groups. A statistical evaluation of the serum AST levels among the groups II, III and IV showed that both groups III and IV which had no difference in between were significantly different in a positive way from group II (p<0.001). As to the serum ALT levels, difference between group II and group III (p<0.001) and group II and group IV (p<0.01) was found significant. No statistical difference was observed in groups I, III and IV for GSH, MDA and CAT levels of the liver. A statistical evaluation of the GSH level in group III and group IV was found to be significantly different from group II (p<0.001) without any difference between them. A similar evaluation for MDA and CAT levels among the revealed no difference between group III and group IV, however, group II showed difference with group II and group IV (p<0.05). Histological findings were in harmony with the biochemical results. We conclude that carvacrol protects the liver against defects caused by ischemia and reperfusion, and carvacrol is not hepatotoxic at the applied dosage.

Effect of silymarin and vitamin E on gentamicin-induced nephrotoxicity in dogs

Drug-induced nephrotoxicity is an important cause of renal failure in dogs. Aminoglycoside antibiotics, such as gentamicin, can produce nephrotoxicity in dogs, due to in part to an imbalance of pro- and antioxidants (oxidative stress). Silymarin (the mixture of flavonolignans extracted from Silybum marianum) has potentially beneficial antioxidant properties. A control group (saline, group 1, n = 5) was compared with dogs that were administrated gentamicin by intramuscular injection, at dosage of 20 mg/kg, once daily for 9 days (groups 2-5, n = 5 per group). The effects of vitamin E (group 3) and silymarin (group 4) alone and in combination (group 5) were compared for induced nephrotoxicity. Renal function was assessed using serum biochemical markers (creatinine and urea). Malondialdehyde (MDA) concentration were measured as a marker of lipid peroxidation. The activity of total serum antioxidants (TSAO) was assessed as a marker of antioxidant defences. Serum creatinine and urea concentrations were increased significantly and TSAO was decreased significantly in group 2 compared with group 1. Serum creatinine concentrations but not urea concentrations were significantly lower in groups 3 and 4 than in group 2 (P = 0.001). Serum MDA concentrations was significantly different between groups 2 and 3 (P = 0.01), 2 and 4 (P < 0.001) and 4 and 5 (P = 0.01). TSAO activity was significantly in group 4 (silymarin) than in group 2 (P = 0.002). Silymarin and vitamin E decreased gentamicin-induced nephrotoxicity in dogs.

Avaliação bioquímica dos efeitos do pré-condicionamento isquêmico após isquemia e reperfusão hepática em ratos

OBJETIVO: Comparar a lesão hepatocelular ocasionada pelo emprego do pré-condicionamento isquêmico e de duas outras modalidades de clampeamento tríade portal: clampeamento contínuo e intermitente. MÉTODO: Quarenta ratos Wistar foram divididos em quatro grupos de 10 animais cada. No Grupo Sham nenhuma espécie de clampeamento foi adotada. Nos outros três, provocamos isquemia de quarenta minutos por meio do clampeamento do pedículo hepático. No Grupo I esta isquemia foi contínua. No Grupo II, também contínua, mas precedida de cinco minutos de isquemia e 10 minutos de reperfusão (précondicionamento isquêmico). No Grupo III foi realizada isquemia intermitente em ciclos de 10 min de isquemia e cinco minutos de reperfusão. Para avaliar a lesão hepatocelular foi adotada a dosagem de transaminase glutâmico oxalacética (TGO), glutâmico pirúvica (TGP) e lactato desidrogenase (LDH), aferidas no início e no final dos procedimentos. RESULTADOS: Não houve diferença estatística nos valores basais das enzimas estudadas, demonstrando uniformidade nos grupos. Os quatro grupos apresentaram variação significativa de todas as enzimas entre os dois momentos de coleta, porém de forma diferenciada. A variação no Grupo Sham foi menor que a do grupo II. Este foi semelhante ao grupo III e em todos a elevação foi significativamente menor que no grupo I (D do Sham CONCLUSÕES: Em ratos Wistar o clampeamento contínuo do pedículo hepático, precedido de um ciclo de cinco minutos de isquemia e 10 minutos de reperfusão (pré-condicionamento isquêmico) provoca menor lesão hepática do que o clampeamento contínuo e apresenta resultados comparáveis aos obtidos através da utilização do clampeamento intermitente, em fígados normais submetidos a um período de isquemia hepática de 40 minutos e um tempo total de cirurgia de 60 minutos.