Thymoquinone loaded solid lipid nanoparticles counteracts 3-Nitropropionic acid induced motor impairments and neuroinflammation in rat model of Huntington's disease.

Defect in gene transcription, excitotoxicity, neuroinflammation and oxidative stress are the dominant disease process that causes striatal cell loss with motor abnormalities in Huntington's disease (HD). Homogeneous pathological reminiscent of HD was extrapolated in the present study using a potent mitochondrial toxin, 3-Nitropropionic acid (3-NP). Administration of 3-NP for 14 days in the present study portends glial cell activation, N-methyl-D-aspartate (NMDA) receptor stimulation, neuroinflammation and motor deficits. The therapeutic strategy in the present study was improvised by formulating thymoquinone, a biologically active compound into a colloidal carrier namely solid lipid nanoparticles. Treatment with 10 and 20 mg/kg b.w of thymoquinone loaded solid lipid nanoparticles (TQ-SLNs) and 80 mg/kg b.w of thymoquinone suspension (TQ-S) showed a significant (P < 0.01) improvement in ATPases function in 3-NP induced animals than TQ-S (40 mg/kg b.w) treated group. TQ-SLNs (10 and 20 mg/kg) treatment also attenuated the overexpression of glial fibrillary acidic protein (GFAP), pro-inflammatory cytokines and p-p65 NFκB nuclear translocation in 3-NP exposed animals. Further, TQ-SLNs treatment desensitizes NR2B-subtype NMDA receptor, improves tyrosine hydroxylase (TH) immune reactive neurons and ameliorated the motor abnormalities in 3-NP intoxicated animals than TQ-S treated group. Hence, the study signifies that the treatment with lower doses of nanoformulated thymoquinone than thymoquinone suspension can efficiently culminate 3-NP induced HD progression in the striatum of male wistar rats.

Neuroprotective activity of L-theanine on 3-nitropropionic acid-induced neurotoxicity in rat striatum.

The present study has been designed to investigate the protective effect of L-theanine against 3-nitropropionic acid (3-NP)-induced Huntington's disease (HD)-like symptoms in rats. The present experimental protocol design includes systemic 3-NP acid (10 mg/kg intraperitonially) treatment for 14 d. L-theanine (100 and 200 mg/kg) was given orally, once a day, 1 h before 3-NP acid treatment for 14 d. Body weight and behavioral parameters (Morris water maze, open field test (OFT), forced swim test (FST) and rotarod activity) were assessed on 1st, 5th, 10th and 15th day post-3-NP acid administration. Malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) levels and mitochondrial enzyme complex. Succinate dehydrogenase (SDH) were measured on the 15th day in the striatum. Systemic 3-NP acid treatment significantly reduced body weight, locomotor activity and oxidative defense. The mitochondrial enzyme activity was also significantly impaired in the striatum region in 3-NP acid-treated animals. L-theanine (100 and 200 mg/kg b.wt.) treatment significantly attenuated the impairment in behavioral, biochemical and mitochondrial enzyme activities as compared to the 3-NP acid-treated group. The results of the present study suggest that pretreatment with L-theanine significantly attenuated 3-NP induced oxidative stress and restored the decreased SOD, GSH, CAT and SDH activity. It also decreased the neuronal damage as evidenced by histopathological analysis of striatum. Based on the above study, it has been proved that L-theanine has neuroprotective activity against 3-NP induced neurotoxicity.

Fisetin impedes developmental methylmercury neurotoxicity via downregulating apoptotic signalling pathway and upregulating Rho GTPase signalling pathway in hippocampus of F1 generation rats.

Methyl mercury is a teratogenic and neurodevelopmental toxicant in the environment. MeHg affects several biological pathways critical for brain development. The present study validated the effect of Fisetin on developmental MeHg exposure induced alterations in mitochondrial apoptotic pathway and Rho GTPase mRNA expressions in hippocampus of F1 generation rats. Pregnant Wistar rats were grouped as Group I : administered with vehicle control, Group II: MeHg (1.5 mg/kg b.w), Group III: MeHg + Fisetin (10 mg/kg b.w), Group IV: MeHg + Fisetin (30 mg/kg b.w), Group V: MeHg + Fisetin (50 mg/kg b.w), Group VI: MeHg + Fisetin (70 mg/kg b.w), Group VII: Fisetin (30 mg/kg b.w) alone. Fisetin reduced mercury accumulation in offspring brain. In hippocampus, Fisetin preserved mitochondrial total thiol status, glutathione antioxidant system, mitochondrial metabolic integrity and respiratory chain activity. Fisetin ameliorated apoptotic signals by preventing Cytochrome c release, down regulating ERK 1/2 and Caspase 3 gene expression. Fisetin also upregulated mRNA expressions of RhoA/Rac1/Cdc42 in hippocampus. Predominant effect of Fisetin was to reduce mercury accumulation in offspring brain there by diminishing the toxic effect of MeHg. Hence we showed that, gestational intake of Fisetin (30 mg/kg b.w.) impedes developmental MeHg neurotoxicity by regulating mitochondrial apoptotic and Rho GTPase signalling molecules and by reducing the mercury accumulation in hippocampus of F1 generation rats.

Neuroprotective effect of morin on lead acetate- induced apoptosis by preventing cytochrome c translocation via regulation of Bax/Bcl-2 ratio.

Lead (Pb) intoxication is a prevalent type of environmental toxicity as well as minimal amount of lead exposure is liable for neurobehavioral or perhaps intelligence defects. The present study was undertaken to investigate the beneficial effects of morin in protecting the lead acetate (PbAc)-induced oxidative stress in rat brain. PbAc intoxication resulted in motor deficit, memory impairment and oxidative stress Further, PbAc administration alters Bax/Bcl-2 expression thereby increases cytochrome c release from the mitochondria. Treatment with morin at a dose of 40 mg/kg b.wt. significantly restored back the abnormal changes that were noticed in PbAc intoxicated rats. Histopathological sections of cortex, cerebellum and hippocampus showed the extent of neuronal loss in PbAc induced rats and its restoration upon administration of morin. These outcomes imply that morin might be employed therapeutically to chelate toxic metals like Pb, thus possibly lowering PbAc-induced neurotoxicity and tissue damage.

Effect of Gestational Intake of Fisetin (3,3',4',7-Tetrahydroxyflavone) on Developmental Methyl Mercury Neurotoxicity in F1 Generation Rats.

Methyl mercury (MeHg) is a developmental neurotoxin that causes irreversible cognitive damage in offspring of gestationally exposed mothers. Currently, no preventive drugs are established against MeHg developmental neurotoxicity. The neuroprotective effect of gestational administration of a flavanoid against in utero toxicity of MeHg is not explored much. Hence, the present study validated the effect of a bioactive flavanoid, fisetin, on MeHg developmental neurotoxicity outcomes in rat offspring at postnatal weaning age. Pregnant Wistar rats were simultaneously given MeHg (1.5 mg/kg b.w.) and two doses of fisetin (10 and 50 mg/kg b.w. in two separate groups) orally from gestational day (GD) 5 till parturition. Accordingly, after parturition, on postnatal day (PND) 24, weaning F1 generation rats were studied for motor and cognitive behavioural changes. Biochemical and histopathological changes were also studied in the cerebral cortex, cerebellum and hippocampus on PND 25. Administration of fisetin during pregnancy prevented behavioural impairment due to transplacental MeHg exposure in weaning rats. Fisetin decreased the levels of oxidative stress markers, increased enzymatic and non-enzymatic antioxidant levels and increased the activity of membrane-bound ATPases and cholinergic function in F1 generation rats. In light microscopic studies, fisetin treatment protected the specific offspring brain regions from significant morphological aberrations. Between the two doses of fisetin studied, 10 mg/kg b.w. was found to be more satisfactory and effective than 50 mg/kg b.w. The present study shows that intake of fisetin during pregnancy in rats ameliorated in utero MeHg exposure-induced neurotoxicity outcomes in postnatal weaning F1 generation rats.

Mitigating effect of chrysin loaded solid lipid nanoparticles against Amyloid ß25-35 induced oxidative stress in rat hippocampal region: An efficient formulation approach for Alzheimer's disease.

Alzheimer's disease (AD) is the most prevalent form of dementia. Amyloid-ß25-35 (Aß25-35), a well-established neurotoxicant, is reported to be involved in the etiology of AD. Chrysin (CN) with its wide range of biological activities in terms of reversing the neuronal damage once induced is limited due to its compromised bioavailability. Solid lipid nanoparticles (SLNs) on the other hand due to its improved protein stability, avoids proteolytic degradation, as well as sustained release of the incorporated molecules could be widely applied as a drug delivery vehicle. Hence, in the present investigation, we prepared CN loaded SLNs (CN-SLNs) and investigated its therapeutic role in alleviating Aß25-35 administered neuronal damage. All the antioxidant enzymes and non-antioxidant enzyme in hippocampus were reduced significantly (P<0.01) in the Aß25-35 injected group, whereas lipid peroxidation and acetylcholine esterase were increased significantly (P<0.01). These changes were restored significantly (P<0.01) by CN-SLNs (5mg/kg and 10mg/kg) and (P<0.05) by free CN (50mg/kg and 100mg/kg). Aß25-35 also resulted in poor memory retention in behavioral tasks and histopathological sections of the hippocampal region showed the extent of neuronal loss which was thereby restored back on treatment with CN-SLNs and free CN. Our findings demonstrate that the therapeutic efficacy of CN could be attained at lower dose and also its oral bioavailability could be increased by encapsulating CN in SLNs. Thus the results suggest that CN-SLNs could be used as a potential therapeutic and a brain targeting strategy to combat the global burden of Alzheimer's disease.

A novel therapeutic application of solid lipid nanoparticles encapsulated thymoquinone (TQ-SLNs) on 3-nitroproponic acid induced Huntington's disease-like symptoms in wistar rats.

Huntington's disease (HD), a devastating neurodegenerative disease causing a remarkable pathogenesis involves mitochondrial dysfunction and bioenergetics failure. 3-Nitropropionic acid (3-NP) is a unique toxin model of HD that are mainly confined to mitochondrial complex-II inhibition and free radical generation. Recently, several nanoparticle formulations were developed to treat against various neurodegenerative diseases including HD. One among them is solid lipid nanoparticles (SLNs), a colloidal carrier designed to enhance the brain drug delivery and to prolong the bio-availability of drugs in the system. Hence, the present study was framed to evaluate solid lipid nanoparticles encapsulated thymoquinone (TQ-SLNs) in comparison with thymoquinone suspension (TQ-S) against 3-NP induced behavioral despair, oxidative injury and striatal pathology. This study reports that theTQ-SLNs (10 and 20 mg/kg) and TQ-S (80 mg/kg) treated animals showed a significant (P < 0.01) improvement in the muscle strength, rigidity, movement and memory performances on 7th and 14th day behavioral analysis than TQ-S (40 mg/kg) treated group. Similarly, TQ-SLNs highly attenuated the levels of oxidative stress markers such as LPO, NO and protein carbonylsin 3-NP induced animals. Further, TQ-SLNs significantly restored the antioxidant defense system, controls the mitochondrial SDH inhibition and alleviates anti-cholinergic effect upon 3-NP induction. In addition, TQ-SLNs efficiently protected the striatal structural microelements against 3-NP toxicity, which was confirmed by light microscopic studies. Thus, the present investigation, collectively suggests that the low dose of TQ-SLNs supplementation is highly sufficient to attain the effect of TQ-S (80 mg/kg) to attenuate behavioral, biochemical and histological modifications in 3-NP exposed HD model.

Chrysin exerts neuroprotective effects against 3-Nitropropionic acid induced behavioral despair-Mitochondrial dysfunction and striatal apoptosis via upregulating Bcl-2 gene and downregulating Bax-Bad genes in male wistar rats.

3-Nitropropionic acid (3-NP) is an irreversible inhibitor of mitochondrial complex-II that causes transcriptional dysregulation, bioenergetics failure, protein aggregation and oxidative damage similar to Huntington's disease (HD) pathogenesis. Chrysin, a bioactive flavonoid reported to have anti-inflammation, antioxidant, vasorelaxant and neuroprotective property. The present study was framed to determine the neuroprotective efficiency of chrysin upon 3-NP induced oxidative stress, mitochondrial dysfunctions and neurodegeneration. 3-NP (10mg/kg b.w. i.p.) administration for 14days exhibited significant (P<0.01) behavioral alterations, mitochondrial dysfunction and oxidative damages to biomolecules, finally causes cell death. Chrysin at 50mg/kg b.w. orally for 14days improved all the behavioral performances and regulated the complex activities in mitochondria. Further, chrysin diminished the oxidative stress markers (lipid peroxidation, nitrite and protein carbonyls) by significantly (P<0.01) improving the antioxidant status (superoxide dismutase, catalase and reduced glutathione) in striatal mitochondria. Indeed, chrysin prevents apoptosis by upregulating the Bcl-2 mRNA expression and downregulating the pro-apoptotic (Bax, Bad) mRNAs in 3-NP induced condition. Furthermore, the survival of striatal neurons against 3-NP toxicity was enhanced upon chrysin treatment which was evidenced by observing histopathological studies. Hence, the present study collectively suggests that the chrysin can serve as a potential therapeutic agent on 3-NP induced mitochondrial deficits and subsequent apoptosis.

Antihypercholesterolemic effect of Bacopa monniera linn. on high cholesterol diet induced hypercholesterolemia in rats

OBJECTIVE@#To explore the effect of alcoholic extract of Bacopa monniera (AEBM) on high cholesterol diet-induced rats.@*METHODS@#The shade-dried and coarsely powdered whole plant material (Bacopa monniera) was extracted with 90% ethanol, finally filtered and dried in vacuum pump. The experimental rats were divided into 4 groups: control (group-I), Rats fed with hypercholesterolemic diet (HCD) for 45 days [4% cholesterol (w/w) and 1% cholic acid], Rats fed with HCD for 45 days+AEBM (40mg/kg, body weight/day orally) for last 30 days (group-III) and AEBM alone (group-IV). Blood and tissues (Aorta) were removed to ice cold containers for various biochemical and histological analysis.@*RESULTS@#AEBM treatment significantly decreased the levels of TC, TG, PL, LDL, VLDL, atherogenic index, LDL/HDL ratio, and TC/HDL ratio but significantly increased the level of HDL when compared to HCD induced rats. Activities on liver antioxidant status (SOD, CAT, GPx, GR, GST) were significantly raised with concomitant reduction in the level of LPO were obtained in AEBM treated rats when compared to HCD rats. Treatment with AEBM significantly lowered the activity of SGOT, LDH and CPK. Histopathology of aorta of cholesterol fed rat showed intimal thickening and foam cell deposition were noted.@*CONCLUSIONS@#These results suggests that AEBM extended protection against various biochemical changes and aortic pathology in hypercholesterolemic rats. Thus the plant may therefore be useful for therapeutic treatment of clinical conditions associated hypercholesterolemia.