Trajectory of inflammatory and microglial activation markers in the postnatal rabbit brain following intrauterine endotoxin exposure.

BACKGROUND: Maternal infection is a risk factor for periventricular leukomalacia and cerebral palsy (CP) in neonates. We have previously demonstrated hypomyelination and motor deficits in newborn rabbits, as seen in patients with cerebral palsy, following maternal intrauterine endotoxin administration. This was associated with increased microglial activation, primarily involving the periventricular region (PVR). In this study we hypothesized that maternal intrauterine inflammation leads to a pro-inflammatory environment in the PVR that is associated with microglial activation in the first 2 postnatal weeks. METHODS: Timed pregnant New Zealand white rabbits underwent laparotomy on gestational day 28 (G28). They were randomly divided to receive lipopolysaccharide (LPS; 20µg/kg in 1mL saline) (Endotoxin group) or saline (1mL) (control saline, CS group), administrated along the wall of the uterus. The PVR from the CS and Endotoxin kits were harvested at G29 (1day post-injury), postnatal day1 (PND1, 3day post-injury) and PND5 (7days post-injury) for real-time PCR, ELISA and immunohistochemistry. Kits from CS and Endotoxin groups underwent longitudinal MicroPET imaging, with [11C]PK11195, a tracer for microglial activation. RESULTS: We found that intrauterine endotoxin exposure resulted in pro-inflammatory microglial activation in the PVR of rabbits in the first postnatal week. This was evidenced by increased TSPO (translocator protein) expression co-localized with microglia/macrophages in the PVR, and changes in the microglial morphology (ameboid soma and retracted processes). In addition, CD11b level significantly increased with a concomitant decline in the CD45 level in the PVR at G29 and PND1. There was a significant elevation of pro-inflammatory cytokines and iNOS, and decreased anti-inflammatory markers in the Endotoxin kits at G29, PND1 and PND5. Increased [11C]PK11195 binding to the TSPO measured in vivo by PET imaging in the brain of Endotoxin kits was present up to PND14-17. CONCLUSIONS: Our results indicate that a robust pro-inflammatory microglial phenotype/brain milieu commenced within 24h after LPS exposure and persisted through PND5 and in vivo TSPO binding was found at PND14-17. This suggests that there may be a window of opportunity to treat after birth. Therapies aimed at inducing an anti-inflammatory phenotype in microglia might promote recovery in maternal inflammation induced neonatal brain injury.

Toxicity evaluation of magnetic hyperthermia induced by remote actuation of magnetic nanoparticles in 3D micrometastasic tumor tissue analogs for triple negative breast cancer.

Magnetic hyperthermia as a treatment modality is acquiring increased recognition for loco-regional therapy of primary and metastatic lung malignancies by pulmonary delivery of magnetic nanoparticles (MNP). The unique characteristic of magnetic nanoparticles to induce localized hyperthermia in the presence of an alternating magnetic field (AMF) allows for preferential killing of cells at the tumor site. In this study we demonstrate the effect of hyperthermia induced by low and high dose of MNP under the influence of an AMF using 3D tumor tissue analogs (TTA) representing the micrometastatic, perfusion independent stage of triple negative breast cancer (TNBC) that infiltrates the lungs. While application of inhalable magnetic nanocomposite microparticles or magnetic nanocomposites (MnMs) to the micrometastatic TNBC model comprised of TTA generated from cancer and stromal cells, showed no measureable adverse effects in the absence of AMF-exposure, magnetic hyperthermia generated under the influence of an AMF in TTA incubated in a high concentration of MNP (1 mg/mL) caused significant increase in cellular death/damage with mechanical disintegration and release of cell debris indicating the potential of these inhalable composites as a promising approach for thermal treatment of diseased lungs. The novelty and significance of this study lies in the development of methods to evaluate in vitro the application of inhalable composites containing MNPs in thermal therapy using a physiologically relevant metastatic TNBC model representative of the microenvironmental characteristics in secondary lung malignancies.

Radiation-enhanced therapeutic targeting of galectin-1 enriched malignant stroma in triple negative breast cancer.

Currently there are no FDA approved targeted therapies for Triple Negative Breast Cancer (TNBC). Ongoing clinical trials for TNBC have focused primarily on targeting the epithelial cancer cells. However, targeted delivery of cytotoxic payloads to the non-transformed tumor associated-endothelium can prove to be an alternate approach that is currently unexplored. The present study is supported by recent findings on elevated expression of stromal galectin-1 in clinical samples of TNBC and our ongoing findings on stromal targeting of radiation induced galectin-1 by the anginex-conjugated arsenic-cisplatin loaded liposomes using a novel murine tumor model. We demonstrate inhibition of tumor growth and metastasis in response to the multimodal nanotherapeutic strategy using a TNBC model with orthotopic tumors originating from 3D tumor tissue analogs (TTA) comprised of tumor cells, endothelial cells and fibroblasts. The 'rigorous' combined treatment regimen of radiation and targeted liposomes is also shown to be well tolerated. More importantly, the results presented provide a means to exploit clinically relevant radiation dose for concurrent receptor mediated enhanced delivery of chemotherapy while limiting overall toxicity. The proposed study is significant as it falls in line with developing combinatorial therapeutic approaches for stroma-directed tumor targeting using tumor models that have an appropriate representation of the TNBC microenvironment.

Investigating the Radioresistant Properties of Lung Cancer Stem Cells in the Context of the Tumor Microenvironment.

Lung cancer is the most common cause of cancer-related deaths worldwide and non-small cell lung cancer (NSCLC) accounts for ~85% of all lung cancer. While recent research has shown that cancer stem cells (CSC) exhibit radioresistant and chemoresistant properties, current cancer therapy targets the bulk of the tumor burden without accounting for the CSC and the contribution of the tumor microenvironment. CSC interaction with the stroma enhances NSCLC survival, thus limiting the efficacy of treatment. The aim of this study was to elucidate the role of CSC and the microenvironment in conferring radio- or chemoresistance in an in vitro tumor model for NSCLC. The novel in vitro three-dimensional (3D) NSCLC model of color-coded tumor tissue analogs (TTA) that we have developed is comprised of human lung adenocarcinoma cells, fibroblasts, endothelial cells and NSCLC cancer stem cells maintained in low oxygen conditions (5% O2) to recapitulate the physiologic conditions in tumors. Using this model, we demonstrate that a single 5 Gy radiation dose does not inhibit growth of TTA containing CSC and results in elevated expression of cytokines (TGF-α, RANTES, ENA-78) and factors (vimentin, MMP and TIMP), indicative of an invasive and aggressive phenotype. However, combined treatment of single dose or fractionated doses with cisplatin was found to either attenuate or decrease the proliferative effect that radiation exposure alone had on TTA containing CSC maintained in hypoxic conditions. In summary, we utilized a 3D NSCLC model, which had characteristics of the tumor microenvironment and tumor cell heterogeneity, to elucidate the multifactorial nature of radioresistance in tumors.

An in vitro assessment of liposomal topotecan simulating metronomic chemotherapy in combination with radiation in tumor-endothelial spheroids.

Low dose metronomic chemotherapy (LDMC) refers to prolonged administration of low dose chemotherapy designed to minimize toxicity and target the tumor endothelium, causing tumor growth inhibition. Topotecan (TPT) when administered at its maximum tolerated dose (MTD) is often associated with systemic hematological toxicities. Liposomal encapsulation of TPT enhances efficacy by shielding it from systemic clearance, allowing greater uptake and extended tissue exposure in tumors. Extended release of TPT from liposomal formulations also has the potential to mimic metronomic therapies with fewer treatments. Here we investigate potential toxicities of equivalent doses of free and actively loaded liposomal TPT (LTPT) and compare them to a fractionated low dose regimen of free TPT in tumor-endothelial spheroids (TES) with/without radiation exposure for a prolonged period of 10 days. Using confocal microscopy, TPT fluorescence was monitored to determine the accumulation of drug within TES. These studies showed TES, being more reflective of the in vivo tumor microenvironment, were more sensitive to LTPT in comparison to free TPT with radiation. More importantly, the response of TES to low-dose metronomic TPT with radiation was comparable to similar treatment with LTPT. This TES study suggests nanoparticle formulations designed for extended release of drug can simulate LDMC in vivo.

Progressive age-related changes in sleep and EEG profiles in the PLB1Triple mouse model of Alzheimer's disease.

Sleep disturbances are common in Alzheimer's disease (AD) and now assumed to contribute to disease onset and progression. Here, we investigated whether activity, sleep/wake pattern, and electroencephalogram (EEG) profiles are altered in the knock-in PLB1Triple mouse model from 5 to 21 months of age. PLB1Triple mice displayed a progressive increase in wakefulness and non-rapid eye movement sleep fragmentation from 9 months onward, whereas PLB1WT wild type controls showed such deterioration only at 21 months. Impaired habituation to spatial novelty was also detected in PLB1Triple mice. Hippocampal power spectra of transgenic mice revealed progressive, vigilance stage-, brain region-, and age-specific changes. Age had an impact on EEG spectra in both cohorts but led to accelerated genotype-dependent differences, ultimately affecting all bands at 21 months. Overall, although PLB1Triple animals display only subtle amyloid and tau pathologies, robust sleep-wake and EEG abnormalities emerged. We hypothesize that such endophenotypes are sensitive, noninvasive, and reliable biomarker to identify onset and progression of AD.

3D tumor tissue analogs and their orthotopic implants for understanding tumor-targeting of microenvironment-responsive nanosized chemotherapy and radiation.

An appropriate representation of the tumor microenvironment in tumor models can have a pronounced impact on directing combinatorial treatment strategies and cancer nanotherapeutics. The present study develops a novel 3D co-culture spheroid model (3D TNBC) incorporating tumor cells, endothelial cells and fibroblasts as color-coded murine tumor tissue analogs (TTA) to better represent the tumor milieu of triple negative breast cancer in vitro. Implantation of TTA orthotopically in nude mice, resulted in enhanced growth and aggressive metastasis to ectopic sites. Subsequently, the utility of the model is demonstrated for preferential targeting of irradiated tumor endothelial cells via radiation-induced stromal enrichment of galectin-1 using anginex conjugated nanoparticles (nanobins) carrying arsenic trioxide and cisplatin. Demonstration of a multimodal nanotherapeutic system and inclusion of the biological response to radiation using an in vitro/in vivo tumor model incorporating characteristics of tumor microenvironment presents an advance in preclinical evaluation of existing and novel cancer nanotherapies. FROM THE CLINICAL EDITOR: Existing in-vivo tumor models are established by implanting tumor cells into nude mice. Here, the authors described their approach 3D spheres containing tumor cells, enodothelial cells and fibroblasts. This would mimic tumor micro-environment more realistically. This interesting 3D model should reflect more accurately tumor response to various drugs and would enable the design of new treatment modalities.

Insights into accelerated liposomal release of topotecan in plasma monitored by a non-invasive fluorescence spectroscopic method.

A non-invasive fluorescence method was developed to monitor liposomal release kinetics of the anticancer agent topotecan (TPT) in physiological fluids and subsequently used to explore the cause of accelerated release in plasma. Analyses of fluorescence excitation spectra confirmed that unencapsulated TPT exhibits a red shift in its spectrum as pH is increased. This property was used to monitor TPT release from actively loaded liposomal formulations having a low intravesicular pH. Mathematical release models were developed to extract reliable rate constants for TPT release in aqueous solutions monitored by fluorescence and release kinetics obtained by HPLC. Using the fluorescence method, accelerated TPT release was observed in plasma as previously reported in the literature. Simulations to estimate the intravesicular pH were conducted to demonstrate that accelerated release correlated with alterations in the low intravesicular pH. This was attributed to the presence of ammonia in plasma samples rather than proteins and other plasma components generally believed to alter release kinetics in physiological samples. These findings shed light on the critical role that ammonia may play in contributing to the preclinical/clinical variability and performance seen with actively-loaded liposomal formulations of TPT and other weakly-basic anticancer agents.

Biodistribution of fluorescently labeled PAMAM dendrimers in neonatal rabbits: effect of neuroinflammation.

Dendrimers are being explored in many preclinical studies as drug, gene, and imaging agent delivery systems. Understanding their detailed organ, tissue, cellular uptake, and retention can provide valuable insights into their effectiveness as delivery vehicles and the associated toxicity. This work explores a fluorescence-quantification based assay that enables simultaneous quantitative biodistribution and imaging of dendrimers with a single agent. We have labeled an ethylenediamine-core generation-4 hydroxyl-terminated poly(amidoamine) (PAMAM) dendrimer using the fluorescent photostable, near-IR cyanine dye (Cy5) and performed quantitative and qualitative biodistribution of the dendrimer-Cy5 conjugates (D-Cy5) in healthy neonatal rabbits and neonatal rabbits with cerebral palsy (CP). The biodistribution of D-Cy5 and free Cy5 dye was evaluated in newborn rabbits, based on the developed quantification methods using fluorescence spectroscopy, high-performance liquid chromatography (HPLC), and size exclusion chromatography (SEC) and supported by microscopic imaging. The uptake was assessed in the brain, heart, liver, lungs, kidneys, blood serum, and urine. Results obtained based on these three independent methods are in good agreement and indicate the fast renal clearance of D-Cy5 and free Cy5 with relatively higher organs accumulation of the D-Cy5 conjugate. Following systemic administration, the D-Cy5 mainly accumulated in kidneys and bladder at 24 h. The quantitative biodistribution is in good agreement with previous studies based on radiolabeling. These methods for dendrimers quantification are easier and more practical, provide excellent sensitivity (reaching 0.1 ng per gram of tissue), and allow for quantification of dendrimers in different organs over longer time periods without concerns for radioactive decay, while also enabling tissue and cellular imaging in the same animal. In kits with fetal-neuroinflammation induced CP, there was a significantly higher uptake of D-Cy5 in the brain, while biodistribution in other organs was similar to that of healthy kits.

Concurrent quantification of tryptophan and its major metabolites.

An imbalance in tryptophan (TRP) metabolites is associated with several neurological and inflammatory disorders. Therefore, analytical methods allowing for simultaneous quantification of TRP and its major metabolites would be highly desirable, and may be valuable as potential biomarkers. We have developed a HPLC method for concurrent quantitative determination of tryptophan, serotonin, 5-hydroxyindoleacetic acid, kynurenine, and kynurenic acid in tissue and fluids. The method utilizes the intrinsic spectroscopic properties of TRP and its metabolites that enable UV absorbance and fluorescence detection by HPLC, without additional labeling. The origin of the peaks related to analytes of interest was confirmed by UV-Vis spectral patterns using a PDA detector and mass spectrometry. The developed methods were validated in rabbit fetal brain and amniotic fluid at gestational day 29. Results are in excellent agreement with those reported in the literature for the same regions. This method allows for rapid quantification of tryptophan and four of its major metabolites concurrently. A change in the relative ratios of these metabolites can provide important insights in predicting the presence and progression of neuroinflammation in disorders such as cerebral palsy, autism, multiple sclerosis, Alzheimer disease, and schizophrenia.

Tumor microenvironment and nanotherapeutics.

Recent studies delineate a predominant role for the tumor microenvironment in tumor growth and progression. Improved knowledge of cancer biology and investigation of the complex functional interrelation between the cellular and noncellular compartments of the tumor microenvironment have provided an ideal platform for the evolution of novel cancer nanotherapies. In addition, multifunctional "smart" nanoparticles carrying imaging agents and delivering multiple drugs targeted preferentially to the tumor/tumor microenvironment will lead to early diagnosis and better treatment for patients with cancer. The emerging knowledge of the tumor microenvironment has enabled rational designing of nanoparticles for combinatorial treatment strategies that include radiotherapy, antiangiogenesis and chemotherapy. This multimodality approach is thus expected to achieve therapeutic efficacy and enhance the quality of life of cancer patients. This review highlights the unique characteristics of the tumor microenvironment that are exploited by nanotechnology to develop novel drug delivery systems aimed to target the tumor/tumor microenvironment.

Dendrimer-based postnatal therapy for neuroinflammation and cerebral palsy in a rabbit model.

Cerebral palsy (CP) is a chronic childhood disorder with no effective cure. Neuroinflammation, caused by activated microglia and astrocytes, plays a key role in the pathogenesis of CP and disorders such as Alzheimer's disease and multiple sclerosis. Targeting neuroinflammation can be a potent therapeutic strategy. However, delivering drugs across the blood-brain barrier to the target cells for treating diffuse brain injury is a major challenge. We show that systemically administered polyamidoamine dendrimers localize in activated microglia and astrocytes in the brain of newborn rabbits with CP, but not healthy controls. We further demonstrate that dendrimer-based N-acetyl-l-cysteine (NAC) therapy for brain injury suppresses neuroinflammation and leads to a marked improvement in motor function in the CP kits. The well-known and safe clinical profile for NAC, when combined with dendrimer-based targeting, provides opportunities for clinical translation in the treatment of neuroinflammatory disorders in humans. The effectiveness of the dendrimer-NAC treatment, administered in the postnatal period for a prenatal insult, suggests a window of opportunity for treatment of CP in humans after birth.

Abnormal cognition, sleep, EEG and brain metabolism in a novel knock-in Alzheimer mouse, PLB1.

Late-stage neuropathological hallmarks of Alzheimer's disease (AD) are ß-amyloid (ßA) and hyperphosphorylated tau peptides, aggregated into plaques and tangles, respectively. Corresponding phenotypes have been mimicked in existing transgenic mice, however, the translational value of aggressive over-expression has recently been questioned. As controlled gene expression may offer animal models with better predictive validity, we set out to design a transgenic mouse model that circumvents complications arising from pronuclear injection and massive over-expression, by targeted insertion of human mutated amyloid and tau transgenes, under the forebrain- and neurone-specific CaMKIIα promoter, termed PLB1(Double). Crossing with an existing presenilin 1 line resulted in PLB1(Triple) mice. PLB1(Triple) mice presented with stable gene expression and age-related pathology of intra-neuronal amyloid and hyperphosphorylated tau in hippocampus and cortex from 6 months onwards. At this early stage, pre-clinical (18)FDG PET/CT imaging revealed cortical hypometabolism with increased metabolic activity in basal forebrain and ventral midbrain. Quantitative EEG analyses yielded heightened delta power during wakefulness and REM sleep, and time in wakefulness was already reliably enhanced at 6 months of age. These anomalies were paralleled by impairments in long-term and short-term hippocampal plasticity and preceded cognitive deficits in recognition memory, spatial learning, and sleep fragmentation all emerging at ∼12 months. These data suggest that prodromal AD phenotypes can be successfully modelled in transgenic mice devoid of fibrillary plaque or tangle development. PLB1(Triple) mice progress from a mild (MCI-like) state to a more comprehensive AD-relevant phenotype, which are accessible using translational tools such as wireless EEG and microPET/CT.

EEG, activity, and sleep architecture in a transgenic AßPPswe/PSEN1A246E Alzheimer's disease mouse.

Since sleep and electroencephalogram (EEG) disturbances are endophenotypes of Alzheimer's disease (AD) patients alongside cognitive dysfunction, we here characterized these parameters in transgenic mice carrying transgenes for amyloid-ß protein precursor (AßPPswe) and presenilin 1 (PSEN1A246E) at 5 (pre-plaque) and 20 months, relative to PSEN1 and wild-type (WT) mice, using a novel wireless microchip device. While circadian rhythms were not affected, we obtained significantly higher overall activity at 5 months in the AßPP/PSEN1 strain (p < 0.001) compared to both PSEN1 and WT animals. Vigilance staging revealed that AßPP/PSEN1 animals present with an age-independent increase in wakefulness (p < 0.001) and a decrease in non rapid-eye movement (NREM) sleep (p < 0.01). These changes were age- and genotype-dependent only during the light phase, while dark phase activity pattern were equally affected at both ages. In all genotypes, the amount of REM sleep was lower at 20 months indicating a general age-related profile. Spectral power of qEEG changed in AßPP/PSEN1 mice at 5 months during wakefulness and REM sleep; during wakefulness hippocampal delta (0.5-5 Hz) was reduced and theta (5-9 Hz) power enhanced. By contrast, NREM EEG spectra were affected by age and genotype. Interestingly, PSEN1 animals also showed spectral EEG changes, these differed from both WT and AßPP/PSEN1 animals. Our results indicate that AßPP/PSEN1 mice exhibit abnormalities in activity and sleep architecture preceding amyloid plaque deposition as well as age-related changes in cortical EEG power. Though not fully recapitulating the profile of AD patients, this suggests activity and EEG recordings as sensitive and translational biomarkers in murine models.

Curcumin attenuates aluminium-induced functional neurotoxicity in rats.

Curcumin is a polyphenol extracted from the rhizome of Curcuma longa and well known as a multi-functional drug with antioxidative, anti-cancerous and anti-inflammatory activities. Curcumin's antiaging and neuroprotective potential is widely reported. In the present study, effect of curcumin treatment dose 30 mg kg(-1) day(-1) was investigated against aluminium neurotoxicity in young and old animals. Direct and indirect intakes of aluminium have been reported to be involved in the etiology of several neurodegenerative disorders like Alzheimer's and Parkinson's diseases. Long term Al was administered through drinking water at a dose of 50 mg/kg/day for 6 months in both young (4 months) and old (18 months) male Wistar rats. Result obtained demonstrates that curcumin treatment attenuates the Al-induced alterations at biochemical, behavioral and ultrastructural levels which was well reflected in the electrophysiological recordings. Our results indicate that curcumin's ability to bind redox active metals and cross the blood-brain barrier could be playing crucial role in preventing against Al-induced neurotoxicity.

Aging accelerates the progression and manifestation of seizures in post-traumatic model of epilepsy.

Traumatic brain injury is a major risk of post-traumatic epilepsy in a large number of individuals of different age groups. Lots of research has been done to elucidate the mechanism of post-traumatic epileptogenesis but age-related vulnerability to develop traumatic seizures is still unknown. Therefore, in the present study investigations were carried out to characterize the electrobehavioral seizure manifestation and associated alterations in young and old epileptic groups. FeCl(3) injection model was used to induce post-traumatic seizures as this model closely resembles human post-traumatic epilepsy. Synchronized video-EEG monitoring was performed to diagnose manifestation of seizures in young (4 months) and old (18 months) rats. Biochemical and ultrastructural studies were performed to determine the mechanism behind the altered age-related vulnerability for post-traumatic seizures. Our result shows that old rats were more vulnerable to post-traumatic epilepsy due to faster seizure spread and lower latency for generalization of electro-clinical seizure activity. The observed biochemical and microscopic alterations associated with old age positively correlate with the altered susceptibility to develop seizures in old epileptic groups.

Curcumin protects against electrobehavioral progression of seizures in the iron-induced experimental model of epileptogenesis.

The purpose of the study was to investigate whether dietary intake of curcumin can inhibit the onset and progression of seizures and their associated pathophysiology in experimental FeCl(3)-induced epileptogenesis. Curcumin was considered for this study because it can cross the blood-brain barrier and bind redox-active metal ions. It is also well known for its antioxidative, anticancer, and anti-inflammatory properties. In the present study, seizures were induced by intracortical injection of FeCl(3) into young rats. Synchronized video/EEG recordings were obtained to diagnose the progression of seizures. Short-term treatment with a curcumin-supplemented diet (1500 pp mw/w) significantly inhibited the onset of grade III and IV seizures in rats with iron-induced epilepsy. The lower dose of curcumin (500 ppm) was not effective in inhibiting grade III seizures, but retarded the onset and progression of generalized seizures. The seizure-suppressing potential of curcumin is explained by the observed biochemical, behavioral, and ultrastructural results. Our results indicate that curcumin significantly prevents generalization of electroclinical seizure activity as well as the pathogenesis associated with iron-induced epileptogenesis.

Aluminium-induced electrophysiological, biochemical and cognitive modifications in the hippocampus of aging rats.

Aluminium (Al) is the most abundant metal known for its neurotoxicity in humans. It gains easy access to the central nervous system under normal physiological conditions and accumulates in different brain regions. It has been reported to be involved in the etiology of several neurodegenerative diseases. In this study, we have investigated the effects of long-term intake of aluminium chloride (AlCl(3)) on the electrophysiological, behavioral, biochemical and histochemical functions of hippocampus. Wistar rats were fed with AlCl(3) at a dose of 50mg/(kgday) for 6 months in the drinking water. Effect of long-term intake of Al was studied on the electrical activity of hippocampal CA1 and CA3 regions in brain of young and old rats. Morris water maze and open field tests were performed to investigate the cognitive and anxiety status of aging rats intoxicated with aluminium. Our studies indicate that aluminium intake results in increased multiple unit activity and adversely affect the spatial learning and memory abilities of both young and old rats. Aluminium intake also inflicts oxidative stress-related damage to lipids, membrane associated proteins (Na-K ATPase and PKC) and endogenous antioxidant enzyme activity (SOD, GPx and GST). The compromised antioxidant system might be playing a crucial role in the observed Al-induced alterations. We have observed that the magnitude of AlCl(3)-induced alteration was considerably higher in younger group of rats compared to older group. In conclusion, the results of the present study implicates that aluminium treatment exerts its neurotoxic effects by altering the overall physiology of brain, and the induced changes were strongly correlated with each other.

Bacopa monniera prevents from aluminium neurotoxicity in the cerebral cortex of rat brain.

Bacopa monniera is a perennial herb, and is used as a nerve tonic in äyurveda, a traditional medicinal system in India. Aluminium-induced neurotoxicity is well known and different salts of aluminium have been reported to accelerate oxidative damage to biomolecules like lipids, proteins and nucleic acids. The objective of the present study was to investigate whether Bacopa monniera could potentially inhibit aluminium toxicity in the cerebral cortex. Male Wister rats (8 months old) were administered with AlCl(3) orally at a dose of 50mg/kg/day in drinking water for 1 month. Experimental rats were given AlCl(3) along with Bacopa monniera extract at a dose of 40 mg/kg/day. One group of rats was treated with l-deprenyl at a dose of 1mg/kg/day along with AlCl(3) treatment. We have observed that Bacopa monniera prevented accumulation of lipid and protein damage significantly, which resulted from aluminium intake. Decline in the activity of endogenous antioxidant enzymes associated with aluminium administration was also inhibited by Bacopa monniera extract. The potential of Bacopa monniera to inhibit Al-induced oxidative stress was observed to be similar to that of l-deprenyl, which was taken as standard. The potential of Bacopa monniera extract to prevent aluminium neurotoxicity was reflected at the microscopic level as well, indicative of its neuroprotective effects. These findings strongly implicate that Bacopa monniera has potential to protect brain from oxidative damage resulting from aluminium toxicity.

Neuroprotective role of Bacopa monniera extract against aluminium-induced oxidative stress in the hippocampus of rat brain.

Bacopa monniera is a nerve tonic used extensively in traditional Indian medicinal system "Ayurveda". Reports regarding its various antioxidative, adaptogenic and memory enhancing roles have already appeared in the last few decades. In the present study, aluminium chloride (AlCl(3)) was used to generate neurotoxicity. We have investigated the neuroprotective effect of Bacopa extract against aluminium-induced changes in peroxidative products, such as thio-barbituric acid-reactive substance (TBA-RS) and protein carbonyl contents and superoxide dismutase (SOD) activity. Effect on lipofuscin (age pigments) accumulation and ultrastructural changes were also studied. Bacopa effects were compared with those of l-deprenyl. Co-administration of Bacopa extract during aluminium treatment significantly prevented the aluminium-induced decrease in SOD activity as well as the increased oxidative damage to lipids and proteins. Protective effect was also observed at microscopic level. Fluorescence and electron microscopic studies revealed considerable inhibition of intraneuronal lipofuscin accumulation and necrotic alteration in the CA1 region of the hippocampus. Observations showed that Bacopa's neuroprotective effects were comparable to those of l-deprenyl at both biochemical and microscopic levels.