Differential induction of oxidative impairments in brain regions of male mice following subchronic consumption of Khesari dhal (Lathyrus sativus) and detoxified Khesari dhal

Protective effect of Selenium nanoparticle against cyclophosphamide induced hepatotoxicity and genotoxicity in Swiss albino mice

Cyclophosphamide (CP) is the most commonly used chemotherapeutic drug for various types of cancer. However, its use causes severe cytotoxicity to normal cells in human. It is well known that the undesirable side effects are caused due to the formation of reactive oxygen species. Selenium is an essential micronutrient for both animals and humans and has antioxidant and membrane stabilizing property, but selenium is also toxic above certain level. Nano selenium has been well proved to be less toxic than inorganic selenium as well as certain organoselenium compounds. The objective of the study is to evaluate the protective role of Nano-Se against CP-induced hepatotoxicity and genotoxicity in Swiss albino mice. CP was administered intraperitoneally (25 mg/kg b.w.) and Nano-Se was given by oral gavages (2 mg Se/kg b.w.) in concomitant and pretreatment scheme. Intraperitoneal administration of CP induced hepatic damage as indicated by the serum marker enzymes aspartate and alanine transaminases and increased the malonaldehyde level, depleted the glutathione content and antioxidant enzyme activity (glutathione peroxidase, glutathione-s-transferase, superoxide dismutase and catalase), and induced DNA damage and chromosomal aberration. Oral administration of Nano-Se caused a significant reduction in malonaldehyde, ROS level and glutathione levels, restoration of antioxidant enzyme activity, reduction in chromosomal aberration in bone marrow, and DNA damage in lymphocytes and also in bone marrow. Moreover, the chemoprotective efficiency of Nano-Se against CP induced toxicity was confirmed by histopathological evaluation. The results support the protective effect of Nano-Se against CP-induced hepatotoxicity and genotoxicity.

Hepatoprotective properties of sesamin against CCl4 induced oxidative stress-mediated apoptosis in mice via JNK pathway

Sesamin (Ses), one of the major lignan derived from sesame seeds, has been reported to have many benefits and medicinal properties. However, its protective effects against carbon tetrachloride (CCl4) induced injury in liver have not been clarified. The aim of the present study was to investigate the hepatoprotective effects of sesamin on oxidative stress and apoptosis in mice exposed to CCl4. Our data showed that sesamin significantly prevented CCl4-induced hepatotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of liver damage (serum aminotransferase activities) and histopathological analysis. Moreover, CCl4-induced profound elevation of reactive oxygen species (ROS) production and oxidative stress, as evidenced by increasing of lipid peroxidation level and depleting of the total antioxidant capacity (TAC) in liver, were suppressed by treatment with sesamin. Furthermore, TUNEL assay showed that CCl4-induced apoptosis in mouse liver was significantly inhibited by sesamin. In exploring the underlying mechanisms of sesamin action, we found that activities of caspase-3 were markedly inhibited by the treatment of sesamin in the liver of CCl4 treated mice. Sesamin increased expression levels of phosphorylated Jun N-terminal kinases (JNK) in liver, which in turn inactivated pro-apoptotic signaling events restoring the balance between mitochondrial pro- and anti-apoptotic Bcl-2 proteins and decreasing the release of mitochondrial cytochrome c in liver of CCl4 treated mice. JNK was also involved in the mitochondrial extrinsic apoptotic pathways of sesamin effects against CCl4 induced liver injury by regulating the expression levels of phosphorylated c-Jun proteins, necrosis factor-alpha (TNF-α) and Bak. In conclusion, these results suggested that the inhibition of CCl4-induced apoptosis by sesamin is due at least in part to its anti-oxidant activity and its ability to modulate the JNK signaling pathway.

Protective effect of puerarin on lead-induced mouse cognitive impairment via altering activities of acetyl cholinesterase, monoamine oxidase and nitric oxide synthase

Puerarin (PU), a natural flavonoid, has been reported to have many benefits and medicinal properties. The present study aimed to investigate the protective effects of puerarin on neurotoxicity in mice exposed to lead. ICR mice were exposed to lead acetate in the drinking water (500 ppm) with or without puerarin coadministration (100 and 200 mgPU/kg intragastrically once daily) for three months. We found puerarin significantly prevented Pb-induced neurotoxicity in a dose-dependent manner, indicated by behavioral indicators. Puerarin also decreased Pb contents in blood and brain. Puerarin increased activities of acetyl cholinesterase (AChE) and monoamine oxidase (MAO) in brain of Pb-treated mice. Moreover, Pb-induced profound elevation of oxidative stress, as evidenced by increasing of lipid peroxidation level and depleting of total antioxidant capacity in brain, were suppressed by treatment with puerarin. Puerarin markedly increased NO production and PKA activity in brain of Pb-treated mice. Western blot analysis showed that puerarin dramatically increased the expression levels of nNOS, eNOS and phosphor-Akt in brains of Pb-treated mice. In conclusion, these results suggested that puerarin can inhibit Pb-induced neurotoxicity, at least in part, by suppressing oxidative stress, reversing the Pb-induced alterations in transmitters and enzymes and modulating the PKA/Akt/NOS signaling pathway.

Therapeutic efficacy of silymarin from milk thistle in reducing manganese-induced hepatic damage and apoptosis in rats

Oxidative stress has been proposed as a possible mechanism involved in manganese (Mn) toxicity. Using natural antioxidants against metal-induced hepatotoxicity is a modern approach. The present study investigated the beneficial role of silymarin, a natural flavonoid, in Mn-induced hepatotoxicity focusing on histopathology and biochemical approaches. Male Wistar rats were exposed orally to manganese chloride (20 mg/mL) for 30 days followed by intraperitoneal cotreatment with silymarin (100 mg/kg). Exposure to Mn resulted in a significant elevation of the plasma marker enzyme activities and bilirubin level related to liver dysfunction of reactive oxygen species (ROS) production and hepatic oxidative stress indices. This metal reduced the activities of superoxide dismutase, catalase and glutathione peroxidase and nonenzymatic antioxidant levels such as reduced glutathione, total sulfhydryl groups and vitamin C. In addition, it caused hepatic hemorrhage, cellular degeneration and necrosis of hepatocytes as indicated by liver histopathology and DNA fragmentation studies. Coadministration of silymarin alleviated Mn oxidative damage effects by inhibiting ROS generation. Histological studies also supported the beneficial role of silymarin against Mn-induced hepatic damages. Combining all, results suggested that silymarin could protect hepatic tissues against Mn-induced oxidative stress probably through its antioxidant activity. Therefore, its supplementation could provide a new approach for the reduction in hepatic complication due to Mn poisoning.

Effect of thymoquinone on 1,2-dimethyl-hydrazine-induced oxidative stress during initiation and promotion of colon carcinogenesis

We evaluated pre- and post-thymoquinone (TQ) treatment on 1,2-dimethyl-hydrazine (DMH)-induced oxidative stress during initiation and promotion of colon carcinogenesis. Wistar rats were induced with DMH (20mg/kg) for 10 or 20 weeks, and treated with TQ (5mg/kg). Following sacrifice, the colons were analysed for tumour development, reactive oxygen species (ROS) generation, lipid peroxidation [conjugated diene (CD) and malondialdehyde (MDA)], antioxidants [glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) and reduced glutathione (GSH)], and histological changes. Increased ROS levels and lipid peroxidation were seen during tumour initiation and promotion. All ROS-scavenging enzyme activities were increased upon shorter DMH treatment but not following longer treatment, while GSH amount was increased upon both treatments. Oxidative state perturbations were associated with moderate colon dysplasia and 30% tumour incidence at initiation and marked dysplasia and 100% tumour incidence at promotion. TQ pre-treatment restored completely DMH-induced oxidative stress at initiation and established histological changes and tumour development. It also abrogated oxidative status aggravation at promotion, and significantly reduced tumour incidence (67%). By comparison, TQ post-treatment corrected oxidative status and attenuated tumour development at initiation. It slightly reduced MDA and antioxidant level at promotion, with a slight reduction in tumour state and dysplasia degree. TQ is efficacious in protecting and curing DMH-induced initiation phase of colon cancer, while exerting a protective role at promotion. TQ effect seems to be related to its capacity in preventing DMH-induced oxidative stress. These in vivo results support the notion that TQ may be of value as a chemo-preventive alternative in colorectal cancer patients.

Effects of organoselenium compound 2-(5-selenocyanato-pentyl)-benzo[de]isoquinoline 1,3-dione on cisplatin induced nephrotoxicity and genotoxicity: an investigation of the influence of the compound on oxidative stress and antioxidant enzyme system

Cisplatin is one of the most active cytotoxic agents used in the treatment of cancer. However, cisplatin therapy is also associated with severe side effects like nephrotoxicity and genotoxicity. Free oxygen radicals are known to play a major role in cisplatin induced toxicities. Selenium is believed to be an important trace element and dietary antioxidant because of its ability to scavenge free oxygen radicals, thereby preventing cells from oxidative stress. The purpose of this study is to evaluate the protective role of a novel naphthalimide based organoselenium compound 2-(5-selenocyanato-pentyl)-benzo[de]isoquinoline 1,3-dione against cisplatin induced toxicities in Swiss albino mice. Cisplatin was administered intraperitoneally (5 mg/kg b.w.) and the organoselenium compound was given by oral gavages (3 mg/kg b.w.) in concomitant and pretreatment schedule. The results showed that the test compound substantially reduced cisplatin induced reactive oxygen species generation and lipid peroxidation in kidney as well as blood urea nitrogen and creatinine levels in serum. Treatment with organoselenium compound was also able to restore the renal antioxidant system by modulating the cisplatin induced depleted activities of glutathione S-transferase, thioredoxin reductase, superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione level. In addition, the organoselenium compound could efficiently minimize cisplatin induced chromosomal aberrations in bone marrow cells and extent of DNA damage in lymphocytes. Furthermore, the chemoprotective efficacy of the compound against cisplatin induced toxicity was confirmed by histopathological evaluation. The results suggest that the organoselenium compound has the potential to protect against cisplatin induced nephrotoxicity and genotoxicity in part by scavenging reactive oxygen species and by up regulating the antioxidant enzyme system.

Neuromodulatory propensity of Bacopa monnieri leaf extract against 3-nitropropionic acid-induced oxidative stress: in vitro and in vivo evidences

We previously reported the propensity of Bacopa monnieri (BM) leaf powder to modulate endogenous levels of oxidative stress markers in the brain of prepubertal mice. In this study, we tested the hypothesis that pretreatment with an alcoholic extract of BM (BME) could provide neuroprotection against 3-nitropropionic acid (3-NPA)-induced oxidative stress under in vitro and in vivo conditions. In chemical systems, BME exhibited multiple free radical scavenging ability. Further, BME pretreatment completely abolished 3-NPA-induced oxidative stress response in brain (striatum, St) mitochondria in vitro. Likewise, pretreatment of dopaminergic (N27 cell lines) cells with BME not only abrogated the generation of reactive oxygen species (ROS) levels, but also offered marked protection against 3-NPA-mediated cytotoxicity. These findings were further validated employing a 3-NPA mice model in vivo. We determined the degree of oxidative stress induction, redox status, enzymic antioxidants, protein oxidation, and cholinergic function in various brain regions of male mice provided with BME for 10 days (prophylaxis) followed by 3-NPA challenge (75 mg/kg bw/day, i.p.). BME prophylaxis completely prevented 3-NPA-induced oxidative dysfunctions in St and other brain regions. 3-NPA-induced robust elevation of oxidative markers (malondialdehyde levels, ROS generation, hydroperoxide levels and protein carbonyls) in cytosol of brain regions was predominantly abolished among mice given BME prophylaxis. Interestingly, BME prophylaxis also prevented the depletion of reduced glutathione, thiol levels, and perturbations in antioxidant enzymes caused by 3-NPA. Collectively these findings provide evidence on the significant prophylactic neuroprotective efficacy of BME in prepubertal mice brain. Based on these data, it is hypothesized that BME can serve as a useful adjuvant in protecting brain against oxidative-mediated neurodegenerative disorders involving oxidative stress conditions.

Bacopa monnieri extract offsets rotenone-induced cytotoxicity in dopaminergic cells and oxidative impairments in mice brain

Bacopa monnieri (BM), an ayurvedic medicinal herb is widely known for its memory enhancing ability and improvement of brain function. In this study, we tested the hypothesis that BM extract (BME) could offset neurotoxicant-induced oxidative dysfunctions in developing brain in a rotenone (ROT) mouse model. Pretreatment of dopaminergic (N27 cell lines) cells with BME exhibited significant cytoprotective effect as evidenced by the attenuation of ROT-induced oxidative stress and cell death. Further, the neuroprotective efficacy of BME was assessed in prepubertal mice administered ROT (i.p. 1.0 mg/kg b.w./day) for 7 days. BME treatment significantly offset ROT-induced oxidative damage in striatum (St) and other brain regions as evident by the normalized levels of oxidative markers (malondialdehyde, ROS levels, and hydroperoxides) and restoration of depleted GSH levels. Further, BME effectively normalized the protein carbonyl content in all brain regions suggesting its ability to prevent protein oxidation. Furthermore, BME treatment restored the activity levels of cytosolic antioxidant enzymes, neurotransmitter function, and dopamine levels in St. Based on our findings, we hypothesize that the neuroprotective effects of BM extract may be at least in part related to its ability to enhance reduced glutathione and antioxidant defenses in brain regions. It is suggested that BM may be effectively exploited as a prophylactic/therapeutic adjuvant for neurodegenerative disorders involving oxidative stress.

Protective role of puerarin on lead-induced alterations of the hepatic glutathione antioxidant system and hyperlipidemia in rats

Puerarin (PU), a natural flavonoid, has been reported to have many benefits and medicinal properties. The aim of the present study was to investigate the effects of puerarin on hepatic oxidative stress and hyperlipidemia in rats exposed to lead. Our data showed that puerarin significantly prevented lead-induced hepatotoxicity, indicated by both diagnostic indicators of liver damage (serum aminotransferase levels) and histopathological analysis. Moreover, lead-induced profound elevation of ROS production and oxidative stress, as evidenced by increasing of lipid peroxidation level, reducing of GPx, GST, GR and GCL activities and depleting of intracellular reduced GSH level in liver, were suppressed by treatment with puerarin. Furthermore, the increase of serum cholesterol, triglycerides and LDL induced by lead was effectively suppressed by puerarin. The HDL level in the lead treatment rats was also increased by puerarin. Western blot analysis showed that puerarin remarkably inhibited hyperlipidemia by regulating the expression of cholesterol 7a-hydroxylase (CYP7A1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and low-density lipoprotein receptor (LDL-R) in liver of lead treated rats. Altogether, these results suggest that puerarin could protect the lead-induced liver injury and hyperlipidemia by reducing ROS production, renewing the activities of antioxidant enzymes and influencing expression of hepatic lipid biosynthesis and metabolism genes.

Ganoderma applanatum terpenes protect mouse liver against benzo(α)pyren-induced oxidative stress and inflammation

Ganoderma applanatum terpenes (GAT) have been reported to have many benefits and medicinal properties. In this study, we evaluated the protective effect of GAT against benzo(a)pyrene (BaP) induced oxidative stress and inflammation in mouse liver, and explored the potential mechanism of its action. Our data showed that GAT significantly decreased levels of ALT and AST in serum and the liver histological injury in BaP-treated mice. GAT markedly decreased the levels of ROS, MDA and lowered the GSH/GSSG ratio in the liver of BaP-treated mice. Furthermore, GAT markedly inhibited the BaP-induced increase of Cu/Zn-SOD, CAT, GPx and GST activities in the mouse liver. Western blot analysis showed that GAT significantly inhibited inflammation by pressing the expression of IL-1β and COX-2 and inhibiting NF-κB translocation in the liver of BaP-treated mice. In conclusion, these results suggested that GAT could protect the mouse liver against BaP-induced injury by improving hepatic function, attenuating histopathologic changes, decreasing levels of ROS and MDA, renewing the activities of antioxidant enzymes and suppressing inflammatory response.

Bacopa monnieri modulates endogenous cytoplasmic and mitochondrial oxidative markers in prepubertal mice brain

Bacopa monnieri (BM) an herb, found throughout the Indian subcontinent in wet, damp and marshy areas is used in Ayurvedic system of medicine for improving intellect/memory, treatment of anxiety and neuropharmacological disorders. Although extensively given to children as a memory enhancer, no data exists on its ability to modulate neuronal oxidative stress in prepubertal animal models. Hence in this study, we examined if dietary intake of BM leaf powder has the propensity to modulate endogenous markers of oxidative stress, redox status (reduced GSH, thiol status), response of antioxidant defenses (enzymic), protein oxidation and cholinergic function in various brain regions of prepubertal (PP) mice. PP mice maintained on a BM-enriched diet (0.5 and 1%) for 4 weeks showed a significant diminution of basal oxidative markers (malondialdehyde levels, reactive species generation, hydroperoxide levels and protein carbonyls) in both cytoplasm and mitochondria of all brain regions. This was accompanied with enhanced reduced glutathione, thiol levels and elevated activities of antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase). Significant reduction in the activity of acetyl cholinesterase enzyme in all brain regions suggested the potential of BM leaf powder to modulate cholinergic function. Further evidence that dietary intake of BM leaf powder confers the prepubertal brain with additional capacity to cope up with neurotoxic prooxidants was obtained by exposing cortical/cerebellar synaptosomes of normal and BM fed mice to 3-nitropropionic acid (3-NPA). While synaptosomes from control mice exhibited a concentration related lipid peroxidation and ROS generation, synaptosomes obtained from BM fed mice showed only a marginal induction at the highest concentration clearly suggesting their increased resistance to 3-NPA-induced oxidative stress. Collectively these data clearly indicate the potential of Bacopa monnieri to modulate endogenous markers of oxidative stress in brain tissue of PP mice. Based on these results, it is hypothesized that dietary intake of BM leaf powder confers neuroprotective advantage and is likely to be effective as a prophylactic/therapeutic agent for neurodegenerative disorders involving oxidative stress.

Quercetin protects the rat kidney against oxidative stress-mediated DNA damage and apoptosis induced by lead

Quercetin, a flavonoid, effectively improved the lead-induced histology changes including structure damage and leukocyte infiltration in rat kidney. The present study was designed to explore the protective mechanism of quercetin against lead-induced oxidative DNA damage and apoptosis in rat kidney. We found that quercetin markedly decreased the ROS level and lowered the GSH/GSSG ratio in the kidney of lead-treated rat. The increase of 8-hydroxydeoxyguanosine level in the kidney of lead-treated rat was effectively suppressed by quercetin. Furthermore, quercetin markedly restored Cu/Zn-SOD, CAT and GPx activities in the kidney of lead-treated rat. TUNEL assay showed that lead-induced apoptosis in rat kidney was significantly inhibited by quercetin, which might be attributed to its antioxidant property. In conclusion, these results suggested that quercetin could protect the rat kidney against lead-induced injury by improving renal function, attenuating histopathologic changes, reducing ROS production, renewing the activities of antioxidant enzymes, decreasing DNA oxidative damage and apoptosis.

Quercetin activates AMP-activated protein kinase by reducing PP2C expression protecting old mouse brain against high cholesterol-induced neurotoxicity

It is known that a high-cholesterol diet induces oxidative stress, inflammatory response, and beta-amyloid (Abeta) accumulation in mouse brain, resulting in neurodegenerative changes. Quercetin, a naturally occurring flavonoid, has been reported to possess numerous biological activities beneficial to health. Our previous studies have demonstrated that quercetin protects mouse brain against D-galactose-induced oxidative damage. Against this background, we evaluated the effect of quercetin on high-cholesterol-induced neurotoxicity in old mice and explored its potential mechanism. Our results showed that oral administration of quercetin significantly improved the behavioural performance of high-cholesterol-fed old mice in both a step-through test and the Morris water maze task. This is at least in part caused by decreasing ROS and protein carbonyl levels and restoring Cu--Zn superoxide dismutase (Cu, Zn-SOD) activity. Furthermore, quercetin also significantly activated the AMP-activated protein kinase (AMPK) via down-regulation of protein phosphatase 2C (PP2C), which reduced the integral optical density (IOD) of activated microglia cells and CD11b expression, down-regulated iNOS and cyclooxygenase-2 (COX-2) expression, and decreased IL-1beta, IL-6, and TNF-alpha expression in the brains of high-cholesterol-fed old mice through the suppression of NF-kappaB p65 nuclear translocation. Moreover, AMPK activation significantly increased 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and acetyl-CoA carboxylase (ACC) phosphorylation and reduced fatty acid synthase (FAS) expression in the brains of high-cholesterol-fed old mice, which reduced cholesterol levels, down-regulated cholesterol 24-hydroxylase (CYP46A1) and beta-amyloid converting enzyme 1 (BACE1) expression, decreased eukaryotic translation initiation factor 2alpha (eIF2alpha) phosphorylation, and lowered Abeta deposits. However, the neuroprotective effect of quercetin was weakened by intraperitoneal injection of compound C, an AMPK inhibitor. These results suggest that AMPK activated by quercetin may be a potential target to enhance the resistance of neurons to age-related diseases.

Effect of Centella asiatica leaf powder on oxidative markers in brain regions of prepubertal mice in vivo and its in vitro efficacy to ameliorate 3-NPA-induced oxidative stress in mitochondria

Centella asiatica (CA) is a common medicinal plant used in the ayurvedic system of medicine to treat various ailments and as a memory enhancer. Despite its extensive usage in children, data on its ability to modulate neuronal oxidative stress in prepubertal rodents are limited. Hence in the present study we have addressed primarily two questions (i) whether dietary intake of CA leaf powder possess the propensity to modulate endogenous oxidative markers in mouse brain regions and (ii) the efficacy of CA aqueous extract to abrogate 3-nitropropionic acid (3-NPA)-induced oxidative stress in brain mitochondria in vitro. Prepubertal male mice were fed CA-incorporated diet (0.5 and 1%) for 4 weeks, and biochemical markers of oxidative stress in brain regions were determined. Mice fed CA showed significant diminution in the levels of malondialdehyde (30-50%), reactive oxygen species (32-42%) and hydroperoxide levels (30-35%), which was accompanied by enhanced activities of antioxidant enzymes in all brain regions. While the levels of reduced glutathione and total thiols were elevated, the protein carbonyl content was decreased in brain among CA-fed mice. Interestingly, the oxidative markers among brain mitochondria of CA-fed mice were also significantly diminished (malondialdehyde, 25%; ROS, 30%; hydroperoxides, 35% and protein carbonyls, 28%). Further, the aqueous extract of CA showed significant free radical scavenging activity determined in established chemical test systems (viz., DPPH, superoxide and hydroxyl radical scavenging activity). Furthermore, the aqueous extract of CA markedly ameliorated the 3-NPA induced oxidative stress response in brain mitochondria under in vitro exposure,. Taken together, these data suggest that CA has the propensity to modulate both endogenous and neurotoxicant induced oxidative impairments in the brain and may be effectively employed as a neuroprotective adjuvant to abrogate oxidative stress in vivo.