Rotenone Research Articles

The cannabinoid receptor I (CB1) enhanced the osteogenic differentiation of BMSCs by rescue impaired mitochondrial metabolism function under inflammatory condition

BackgroundPeriodontitis is a chronic infectious disease leading to bone resorption and periodontal tissue disruption under inflammatory stimulation. The osteogenic differentiation ability of mesenchymal stem cells (MSCs) is impaired under the inflammatory environment, which limits the effect of treatment. The cannabinoid receptor I (CB1) is the main effector of the endogenous cannabinoid system (ECS), and our previous study verified that CB1 could enhance the osteo/dentinogenic differentiation of dental MSCs, which might be a target for alveolar bone regeneration. However, the effect of CB1 on the osteogenic differentiation of MSCs derived from bone remains unknown. In present study, we investigated the role and mechanism of CB1 on mitochondrial function and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) under inflammatory environment.MethodsAlkaline phosphatase (ALP) activity, alizarin red staining, quantitative calcium analysis, and osteogenic markers were used to detect the osteogenic differentiation ability of BMSCs. Real-time RT-PCR and Western blot were used to detect the gene expression. Seahorse Cell Mito Stress Test was used to detect the oxygen consumption rate (OCR). JC-10 assay was used to determine the mitochondrial membrane potential (MMP).ResultsCB1 increased osteogenic differentiation potential and mitochondrial energy metabolism, including the OCR, MMP, and enhanced the expressions of Nrf1 and Nrf2 in hBMSCs without or with TNF-α or INF-γ stimulation. Then, the inhibitor of mitochondrial electron transport chain (ETC), rotenone (ROT), inhibited the osteogenic differentiation in hBMSCs, and CB1 could rescue ROT impaired osteogenic differentiation potentials of hBMSCs without or with TNF-α or INF-γ stimulation. Activation of ETC by Coenzyme Q10 (CoQ10) could restore the impaired osteogenic differentiation of hBMSCs by depletion of CB1 without or with TNF-α or INF-γ stimulation. Mechanismly, CB1 could activate the JNK signaling pathway, p38 MAPK signaling pathway, and inhibit the Erk1/2 signaling pathway.ConclusionsThe activating of CB1 enhanced the osteogenic differentiation by rescuing the mitochondrial metabolism function in hBMSCs under the inflammatory environment, suggesting that CB1 is a potential target for enhancing bone regeneration under the inflammatory environment.

L-Theanine Ameliorated Rotenone-Induced Parkinsonism-like Symptoms in Rats.

Rotenone (RO)-induced neurotoxicity exhibits pathophysiological features similar to those reported in patients with Parkinson's disease (PD), such as nitrosative and oxidative stress, mitochondrial dysfunction, and neural cytoarchitecture alterations in the substantia nigra pars compacta (SNpc)/striatum (ST), which has been used for decades as an animal model of PD in humans. L-Theanine (LT), a major amino acid component of green tea, exhibits potent antioxidant and anti-inflammatory activities and protects against various neural injuries. We investigated the potential therapeutic effects of LT on RO-induced behavioral and neurochemical dysfunction in rats and the neuroprotective mechanisms underlying these effects. Unilateral stereotaxic intranigral infusion of RO into the SNpc to induce PD-like manifestations induced significant behavioral impairment as evaluated using an open field test, rotarod test, grip strength measurement, and beam-crossing task in rats. LT treatment (300mg/kg i.p., 21days) ameliorated most RO-induced behavioral impairments. In addition, LT treatment reduced nitric oxide level and lipid peroxidation production, increased mitochondrial function and integrity, as well as the activities of mitochondrial complexes I, II, IV, and V, and reduced the levels of neuroinflammatory and apoptotic markers in the SNpc and ameliorated the levels of catecholamines, GABA and glutamate in the ST induced by RO. These results demonstrate the possible therapeutic effects of LT against RO-induced behavioral impairments, including antioxidative effects, prevention of mitochondrial dysfunction, prevention of neurochemical deficiency, anti-neuroinflammatory effects, and anti-apoptotic effects. This is the first report on the neuroprotective effect of LT against RO-induced behavioral impairments, and the above evidence provides a potential clinically relevant role for LT in the management of human PD.

Neuroprotective effects of indole-3-carbinol on the rotenone rat model of Parkinson's disease: Impact of the SIRT1-AMPK signaling pathway

Parkinson’s disease (PD) is the second most common progressive neurodegenerative disorder. Although mounting studies have been conducted, no effective therapy is available to halt its progression. Indole-3-carbinol (I3C) is a naturally occurring compound obtained by β-thioglucosidase-mediated autolysis of glucobrassicin in cruciferous vegetables. Besides its powerful antioxidant activity, I3C has shown neuroprotection against depression and chemically induced neurotoxicity via its anti-inflammatory and antiapoptotic effects. This study aimed to investigate the neuroprotective effects of I3C against rotenone (ROT)-induced PD in male albino rats. The possible protective mechanisms were also explored. PD was induced by subcutaneous administration of ROT (2 mg/kg) for 28 days. The effects of I3C (25, 50, and 100 mg/kg/day) were assessed by catalepsy test (bar test), spontaneous locomotor activity, rotarod test, weight change, tyrosine hydroxylase (TH) expression, α-synuclein (α-Syn) expression, striatal dopamine (DA) content, and histological examination. The highest dose of I3C (100 mg/kg) was the most effective to prevent ROT-mediated motor dysfunctions and amend striatal DA decrease, weight loss, neurodegeneration, TH expression reduction, and α-Syn expression increase in both the midbrain and striatum. Further mechanistic investigations revealed that the neuroprotective effects of I3C are partially attributed to its anti-inflammatory and antiapoptotic effects and the activation of the sirtuin 1/AMP-activated protein kinase pathway. Altogether, these results suggested that I3C could attenuate biochemical, molecular, and functional changes in a rat PD model with following repeated rotenone exposures.

Unraveling the Neuroprotective Effect of Tinospora cordifolia in a Parkinsonian Mouse Model through the Proteomics Approach.

Stress-induced dopaminergic (DAergic) neuronal death in the midbrain region is the primary cause of Parkinson's disease (PD). Following the discovery of l-dopa, multiple drugs have been developed to improve the lifestyle of PD patients; however, none have been suitable for clinical use due to their multiple side effects. Tinospora cordifolia has been used in traditional medicines to treat neurodegenerative diseases. Previously, we reported the neuroprotective role of Tc via inhibition of NF-κB-associated proinflammatory cytokines against MPTP-intoxicated Parkinsonian mice. In the present study, we investigated the neuroprotective molecular mechanism of Tc in a rotenone (ROT)-intoxicated mouse model, using a proteomics approach. Mice were pretreated with Tc extract by oral administration, followed by ROT intoxication. Behavioral tests were performed to check motor functions of mice. Protein was isolated, and label-free quantification (LFQ) was carried out to identify differentially expressed protein (DEP) in control vs PD and PD vs treatment groups. Results were validated by qRT-PCR with the expression of target genes correlating with the proteomics data. In this study, we report 800 DEPs in control vs PD and 133 in PD vs treatment groups. In silico tools demonstrate significant enrichment of biochemical and molecular pathways with DEPs, which are known to be important for PD progression including mitochondrial gene expression, PD pathways, TGF-β signaling, and Alzheimer's disease. This study provides novel insights into the PD progression as well as new therapeutic targets. More importantly, it demonstrates that Tc can exert therapeutic effects by regulating multiple pathways, resulting in neuroprotection.

Roflupram protects against rotenone-induced neurotoxicity and facilitates α-synuclein degradation in Parkinson's disease models.

We have previously shown that roflupram (ROF) protects against MPP+-induced neuronal damage in models of Parkinson's disease (PD). Since impaired degradation of α-synuclein (α-syn) is one of the key factors that lead to PD, here we investigated whether and how ROF affects the degradation of α-syn in rotenone (ROT)-induced PD models in vivo and in vitro. We showed that pretreatment with ROF (10 μM) significantly attenuated cell apoptosis and reduced the level of α-syn in ROT-treated SH-SY5Y cells. Furthermore, ROF significantly enhanced the lysosomal function, as evidenced by the increased levels of mature cathepsin D (CTSD) and lysosomal-associated membrane protein 1 (LAMP1) through increasing NAD+/NADH and the expression of sirtuin 1 (SIRT1). Pretreatment with an SIRT1 inhibitor selisistat (SELI, 10 μM) attenuated the neuroprotection of ROF, ROF-reduced expression of α-syn, and ROF-increased expression levels of LAMP1 and mature CTSD. Moreover, inhibition of CTSD by pepstatin A (20 μM) attenuated ROF-reduced expression of α-syn. In vivo study was conducted in mice exposed to ROT (10 mg·kg-1·d-1, i.g.) for 6 weeks; then, ROT-treated mice received ROF (0.5, 1, or 2 mg·kg-1·d-1; i.g.) for four weeks. ROF significantly ameliorated motor deficits, which was accompanied by increased expression levels of tyrosine hydroxylase, SIRT1, mature CTSD, and LAMP1, and a reduced level of α-syn in the substantia nigra pars compacta. Taken together, these results demonstrate that ROF exerts a neuroprotective action and reduces the α-syn level in PD models. The mechanisms underlying ROF neuroprotective effects appear to be associated with NAD+/SIRT1-dependent activation of lysosomal function.

Corrective effects of benzodiazepine derivative – diazepinone on purine and lipid metabolism in the liver of rats with Parkinson’s disease

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra. The cause of PD is not fully understood, and effective treatments still do not exist. It is believed that oxidative stress, mitochondrial dysfunction, and impaired lipid metabolism may underlie the pathogenesis of PD. Bile contains the breakdown products of various compounds that form in hepatocytes. This study aimed to evaluate the effect of a new benzodiazepine derivative - diazepinone (DP) on purine and lipid metabolism in the liver of rats with PD caused by rotenone (ROT) by studying the composition of bile. The concentration of ATP, ADP, AMP, xanthine, hypoxanthine, phospholipids (PL), cholesterol (CHOL), cholesterol esters (ECHOL), free fatty acids (FFA), and triglycerides (TG) was quantified in bile samples by thin-layer chromatography. Our findings suggested that the ratio of AMP/ ATP in bile increased almost threefold under the influence of ROT, and with DP, it exceeded the norm by only 1.6 times. ROT also increased the content of xanthine and hypoxanthine by 28.6% and 66.7%, respectively. DP did not affect the increased xanthine content relative to control but significantly reduced the level of hypoxanthine (up to 22.2%, above normal). In addition, ROT reduced the content of bile PL, CHOL, ECHOL, TG by 23.9%, 38.6%, 47.5%, 39.2 %, respectively. Under the influence of the DP, all the above indicators returned to the level of control. Thus, diazepinone improves both the metabolism of purines and lipids in the liver of rats with ROT-simulated PD. This drug may become a therapeutic agent for treating PD and possibly other neurodegenerative diseases in the future.

Acteoside exerts neuroprotection effects in the model of Parkinson's disease via inducing autophagy: Network pharmacology and experimental study

Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease. At present, the incidence rate of PD is increasing worldwide, there is no effective cure available so far, and currently using drugs are still limited in efficacy due to serious side effects. Acteoside (ACT) is an active ingredient of many valuable medicinal plants, possesses potential therapeutic effects on many pathological conditions. In this study, we dissected the neuroprotection effects of ACT on PD and its potential molecular mechanism in our PD model pathology based on network pharmacology prediction and experimental assays. Network pharmacology and bioinformatics analysis demonstrated that ACT has 381 potential targets; among them 78 putative targets associated with PD were closely related to cellular autophagy and apoptotic processes. Our experimental results showed that ACT exerted significant neuroprotection effects on Rotenone (ROT) -induced injury of neuronal cells and Drosophila melanogaster (D. melanogaster). Meanwhile, ACT treatment induced autophagy in both neuronal cell lines and fat bodies of D. melanogaster. Furthermore, ACT treatment decreased ROT induced apoptotic rate and reactive oxygen species production, increased mitochondrial membrane potentials in neuronal cells, and promoted clearance of α-synuclein (SNCA) aggregations in SNCA overexpressed cell model through the autophagy-lysosome pathway. Interestingly, ACT treatment significantly enhanced mitophagy and protected cell injury in neuronal cells. Taken together, ACT may represent a potent stimulator of mitophagy pathway, thereby exerts preventive and therapeutic effects against neurodegenerative diseases such as PD by clearing pathogenic proteins and impaired cellular organelles like damaged mitochondria in neurons.

Biogenic zinc-oxide nanoparticles of Moringa oleifera leaves abrogates rotenone induced neuroendocrine toxicity by regulation of oxidative stress and acetylcholinesterase activity

Zinc oxide nanoparticles (ZnONPs) from plant origin were postulated to regulate complex hormonal control through the hypothalamus– pituitary–testicular axis and somatic cells due to their unique small size and effective drug delivery to target tissues. This study therefore investigates the biogenic synthesis of zinc oxide nanoparticles (ZnO NPs) from Moringa oleifera leaves on key endocrine hormones (LH, FSH and testosterone), MDA level, antioxidant enzymes (SOD and CAT), acetylcholineesterase (AChE) activity and reactive nitrogen species (NO•) level in rotenone induced male rat. The animals were divided into six groups (n = 8). Group I was orally given olive oil as vehicle; Group II received 60 mg/kg of rotenone (RTNE) only; Group III (RTNE + ZnONPs) received 60 mg/kg RTNE + 10 mg/kg ZnONPs; Group IV (RTNE + ZnCAP) received 60 mg/kg RTNE + 50 mg/kg zinc capsule; Group V (ZnONPs only) received 10 mg/kg ZnONPs only. Group VI received 50 mg/kg ZnCAP only. The experiment lasted 10 days. TEM and XRD images revealed ZnO NPs. Moreover, the presence of organic molecules in bio-reduction reactions from the FTIR spectrum showed the stabilization of the nanoparticles. Also, animals induced with rotenone exhibited impairment in the leydig cells by depleting LH, FSH, and testosterone levels with reduced AChE activity and significant (p < 0.05) alteration in cerebral enzymatic antioxidants. There was also brain increase in NO• production: marker of pro-inflammation. Nanotherapeutically, ZnONPs regulated hypothalamus–pituitary–testicular axis via modulation of cerebral NO•, FSH, LH, testosterone and AChE activity with induction of anti-oxidative enzymes.

Metabolic shifts modulate lung injury caused by infection with H1N1 influenza A virus

Influenza A virus (IAV) infection alters lung epithelial cell metabolism in vitro by promoting a glycolytic shift. We hypothesized that this shift benefits the virus rather than the host and that inhibition of glycolysis would improve infection outcomes. A/WSN/33 IAV-inoculated C57BL/6 mice were treated daily from 1 day post-inoculation (d.p.i.) with 2-deoxy-d-glucose (2-DG) to inhibit glycolysis and with the pyruvate dehydrogenase kinase (PDK) inhibitor dichloroacetate (DCA) to promote flux through the TCA cycle. To block OXPHOS, mice were treated every other day from 1 d.p.i. with the Complex I inhibitor rotenone (ROT). 2-DG significantly decreased nocturnal activity, reduced respiratory exchange ratios, worsened hypoxemia, exacerbated lung dysfunction, and increased humoral inflammation at 6 d.p.i. DCA and ROT treatment normalized oxygenation and airway resistance and attenuated IAV-induced pulmonary edema, histopathology, and nitrotyrosine formation. None of the treatments altered viral replication. These data suggest that a shift to glycolysis is host-protective in influenza.

Protective Effects of Quercetin against Rotenone Induced Histopathological and Biochemical Alteration in Testes of Mice

The present work aimed to investigate the protective role of quercetin against rotenone-induced testes damage at the level of oxidative stress and histological alteration. Reproductive toxicity was induced in mice by oral treatment of rotenone, 5 mg/kg body weight daily for 60 days, dissolve in sunflower oil as a vehicle. The quercetin was orally administered 30 mg/kg body weight daily for 60 days along with rotenone. The results of the current study showed that rotenone significantly reduced the Reduced glutathione (GSH) content and decreased the activities of Catalase (CAT) and Superoxide dismutase (SOD) and increased the oxidative markers such as Lipid peroxidation (LPO), and Nitric Oxide (NO) in rotenone treated group as compared to control. Co-administration of quercetin along with rotenone significantly reduced LPO and NO in the testes of mice when compared to rotenone alone group, increased the content of GSH, enhanced activities of CAT, and SOD when compared to rotenone the only group. The results of histological studies of the rotenone treated group showed a reduced number of germ cells, sperms loss, abnormality in seminiferous tubules, and degeneration of interstitial cells was found in the rotenone treated group as compared to control. While co-administration of quercetin reverses these adverse effects. The results of the current study clearly indicated that rotenone exerts harmful effects on the testes and co-administration of quercetin along with rotenone significantly protects damage caused by rotenone.

Can Cranberry Juice Protect against Rotenone-Induced Toxicity in Rats?

The high polyphenols content of cranberry accounts for its strong antioxidant activity underlying the beneficial health effects of this fruit. Rotenone (ROT) is a specific inhibitor of mitochondrial complex I in the brain which leads to the generation of oxidative stress. To date, there are few data indicating that toxicity of ROT is not limited to the brain but can also affect other tissues. We aimed to examine whether ROT-induced oxidative stress could be counteracted by cranberry juice not only in the brain but also in the liver and kidney. Wistar rats were given the combined treatment with ROT and cranberry juice (CJ) for 35 days. Parameters of antioxidant status were determined in the organs. ROT enhanced lipid peroxidation solely in the brain. The increase in the DNA damage was noticed in all organs examined and in leukocytes. The beneficial effect of CJ on these parameters appeared only in the brain. Additionally, CJ decreased the activity of serum hepatic enzymes. The effect of CJ on antioxidant enzymes was not consistent, however, in some organs, CJ reversed changes evoked by ROT. Summing up, ROT can cause oxidative damage not only in the brain but also in other organs. CJ demonstrated a protective effect against ROT-induced toxicity.

Photochemical Pathways of Rotenone and Deguelin Degradation: Implications for Rotenoid Attenuation and Persistence in High-Latitude Lakes.

The direct and indirect photochemical degradation of rotenone (ROT) and deguelin (DEG), the primary reduced nicotinamide adenine dinucleotide-inhibiting rotenoid components of the piscicide CFT Legumine, were investigated under simulated sunlight conditions relevant to their dissipation from high-latitude surface waters. Photochemical degradation dominated the elimination of ROT and DEG from surface waters with half-lives ranging from 1.17 to 2.32 and 4.18 to 20.12 h for DEG and ROT, respectively, when the rotenoids were applied in the formulation CFT Legumine. We assessed enhanced degradation processes using argon-purged and cesium chloride-amended water, which demonstrated the rotenoids to rapidly decompose from excited triplet states. We further assessed the influence of reactive oxygen species by hydroxyl radical quenching and thermal generation of singlet oxygen. The studied reactive oxygen species did not significantly contribute; however, alcohols such as isopropanol may inhibit degradation by quenching ROT excited states or preventing intersystem crossing. Finally, we compared photochemical degradation in water collected from Hope Lake, Alaska, to a solution of Suwanee River fulvic acids, which demonstrated that dissolved organic matter (DOM) quality is a major factor that modulates ROT attenuation through a combination of shielding (light attenuation) and excited-state quenching mechanisms and is temperature-dependent. Molecular-level characterizations of DOM may help account for the site-specific degradation of these rotenoids in the environment.

Neural-Induced Human Adipose Tissue-Derived Stem Cells Conditioned Medium Ameliorates Rotenone-Induced Toxicity in SH-SY5Y Cells.

Parkinson’s disease (PD) is an age-related neurodegenerative disease (NDD) characterized by the degenerative loss of dopaminergic neurons in the substantia nigra along with aggregation of α-synuclein (α-syn). Neurogenic differentiation of human adipose-derived stem cells (NI-hADSCs) by supplementary factors for 14 days activates different biological signaling pathways. In this study, we evaluated the therapeutic role of NI-hADSC-conditioned medium (NI-hADSC-CM) in rotenone (ROT)-induced toxicity in SH-SY5Y cells. Increasing concentrations of ROT led to decreased cell survival at 24 and 48 h in a dose- and time-dependent manner. Treatment of NI-hADSC-CM (50% dilution in DMEM) against ROT (0.5 μM) significantly increased the cell survival. ROT toxicity decreased the expression of tyrosine hydroxylase (TH). Western blot analysis of the Triton X-100-soluble fraction revealed that ROT significantly decreased the oligomeric, dimeric, and monomeric phosphorylated Serine129 (p-S129) α-syn, as well as the total monomeric α-syn expression levels. ROT toxicity increased the oligomeric, but decreased the dimeric and monomeric p-S129 α-syn expression levels. Total α-syn expression (in all forms) was increased in the Triton X-100-insoluble fraction, compared to the control. NI-hADSC-CM treatment enhanced the TH expression, stabilized α-syn monomers, reduced the levels of toxic insoluble p-S129 α-syn, improved the expression of neuronal functional proteins, regulated the Bax/Bcl-2 ratio, and upregulated the expression of pro-caspases, along with PARP-1 inactivation. Moreover, hADSC-CM treatment decreased the cell numbers and have no effect against ROT toxicity on SH-SY5Y cells. The therapeutic effects of NI-hADSC-CM was higher than the beneficial effects of hADSC-CM on cellular signaling. From these results, we conclude that NI-hADSC-CM exerts neuroregenerative effects on ROT-induced PD-like impairments in SH-SY5Y cells.

Diet with Low Molecular Weight Chitosan exerts neuromodulation in Rotenone induced Drosophila model of Parkinson's disease

Rotenone (ROT) is well known pesticide been used in agriculture due to its low cost and rapid action. This has also been widely used to establish Parkinson's disease (PD) models in rodents. Here we have evaluated the role of well established potent molecule ‘Low Molecular Weight Chitosan (LMWC)’ against ROT induced neurotoxicity in Drosophila melanogaster. Male adult flies (8–10 days) were induced for neurotoxicity using ROT (500 μM) and treated with LMWC (5 & 10 mg/mL basal media) during 7 days experiment. Subsequently, neurodegenerative and behavioural parameters were assessed. As a result, flies exposed to ROT alone showed decreased locomotor behaviour in negative geotaxis and open-field studies and had a higher incidence of mortality compared to control group. These effects were accompanied by decrease in dopamine level, ETC complexes and increase in reactive oxygen species (ROS) production and cholinergic activities in head and body of the flies, suggesting ROT was able to induce oxidative stress. Co-exposure of LMWC reversed the ROT induced locomotor impairment, exploratory deficits and changes the biochemical parameters to normal level and increased the survival rate to 16 days. Thus, we suggested LMWC may be considered as better supplement in the prevention and management of Parkinson's disease.

α-Bisabolol, a Dietary Bioactive Phytochemical Attenuates Dopaminergic Neurodegeneration through Modulation of Oxidative Stress, Neuroinflammation and Apoptosis in Rotenone-Induced Rat Model of Parkinson's disease.

Rotenone (ROT), a plant-derived pesticide is a well-known environmental neurotoxin associated with causation of Parkinson’s disease (PD). ROT impairs mitochondrial dysfunction being mitochondrial complex-I (MC-1) inhibitor and perturbs antioxidant-oxidant balance that contributes to the onset and development of neuroinflammation and neurodegeneration in PD. Due to the scarcity of agents to prevent the disease or to cure or halt the progression of symptoms of PD, the focus is on exploring agents from naturally occurring dietary phytochemicals. Among numerous phytochemicals, α-Bisabolol (BSB), natural monocyclic sesquiterpene alcohol found in many ornamental flowers and edible plants garnered attention due to its potent pharmacological properties and therapeutic potential. Therefore, the present study investigated the neuroprotective effects of BSB in a rat model of ROT-induced dopaminergic neurodegeneration, a pathogenic feature of PD and underlying mechanism targeting oxidative stress, inflammation and apoptosis. BSB treatment significantly prevented ROT-induced loss of dopaminergic neurons and fibers in the substantia nigra and striatum respectively. BSB treatment also attenuated ROT-induced oxidative stress evidenced by inhibition of MDA formation and GSH depletion as well as improvement in antioxidant enzymes, SOD and catalase. BSB treatment also attenuated ROT-induced activation of the glial cells as well as the induction and release of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and inflammatory mediators (iNOS and COX-2) in the striatum. In addition to countering oxidative stress and inflammation, BSB also attenuated apoptosis of dopaminergic neurons by attenuating downregulation of anti-apoptotic protein Bcl-2 and upregulation of pro-apoptotic proteins Bax, cleaved caspases-3 and 9. Further, BSB was observed to attenuate mitochondrial dysfunction by inhibiting mitochondrial lipid peroxidation, cytochrome-C release and reinstates the levels/activity of ATP and MC-I. The findings of the study demonstrate that BSB treatment salvaged dopaminergic neurons, attenuated microglia and astrocyte activation, induction of inflammatory mediators, proinflammatory cytokines and reduced the expression of pro-apoptotic markers. The in vitro study on ABTS radical revealed the antioxidant potential of BSB. The results of the present study are clearly suggestive of the neuroprotective effects of BSB through antioxidant, anti-inflammatory and anti-apoptotic properties in ROT-induced model of PD.

Atypical Antipsychotic Drug Ziprasidone Protects against Rotenone-Induced Neurotoxicity: An In Vitro Study.

Schizophrenia is a severe, chronic mental illness characterized by delusions, hallucinations, negative symptoms, and cognitive dysfunction. Recently, several studies have demonstrated that the pathogenesis of schizophrenia involves mitochondrial dysfunction and oxidative stress. However, the effect of antipsychotic drugs for these events has been poorly investigated. In the present study, we evaluated the neuroprotective effect of an atypical antipsychotic drug, ziprasidone (ZPD), on rotenone (ROT)-induced neurotoxicity involving oxidative stress in PC12 cells. Our data showed that ZPD treatment promoted the translocation of NF-E2-related factor-2 (Nrf2) from cytoplasm to nucleus and activated the expression of its target genes NAD(P)H quinone oxidoreductase (NQO-1), catalase (CAT), and heme oxygenase (HO-1). Additionally, ZPD prevented ROT-induced cell death and intracellular reactive oxygen species production. Interestingly, the use of serotonin 5-HT1A receptor antagonist 1-(2-methoxyphenyl)-4 (4-(2-phtalimido) butyl) piperazine (NAN-190) completely blocked the protective effect of ZPD against ROT-induced cell death. Our results demonstrate the neuroprotective effect of ZPD against ROT-induced neurotoxicity and suggest that ZPD may be a potential candidate for the prevention of mitochondrial dysfunction and oxidative stress in schizophrenia.

Knockout of VDAC1 in H9c2 Cells Promotes Oxidative Stress-Induced Cell Apoptosis through Decreased Mitochondrial Hexokinase II Binding and Enhanced Glycolytic Stress.

Background/Aims:The role of VDAC1, the most abundant mitochondrial outer membrane protein, in cell death depends on cell types and stimuli. Both silencing and upregulation of VDAC1 in various type of cancer cell lines can stimulate apoptosis. In contrast, in mouse embryonic stem (MES) cells and mouse embryonic fibroblasts (MEFs), the roles of VDAC1 knockout (VDAC1−/−) in apoptotic cell death are contradictory. The contribution and underlying mechanism of VDAC1−/− in oxidative stress-induced cell death in cardiac cells has not been established. We hypothesized that VDAC1 is an essential regulator of oxidative stress-induced cell death in H9c2 cells.Methods:We knocked out VDAC1 in this rat cardiomyoblast cell line with CRISPR-Cas9 genome editing technique to produce VDAC1−/− H9c2 cells, and determined if VDAC1 is critical in promoting cell death via oxidative stress induced by tert-butylhydroper-oxide (tBHP), an organic peroxide, or rotenone (ROT), an inhibitor of mitochondrial complex I by measuring cell viability with MTT assay, cell death with TUNEL stain and LDH release. The mitochondrial and glycolytic stress were examined by measuring O2 consumption rate (OCR) and extracellular acidification rate (ECAR) with a Seahorse XFp analyzer.Results:We found that under control conditions, VDAC1−/− did not affect H9c2 cell proliferation or mitochondrial respiration. However, compared to the wildtype (WT) cells, exposure to either tBHP or ROT enhanced the production of ROS, ECAR, and the proton (H+) production rate (PPR) from glycolysis, as well as promoted apoptotic cell death in VDAC1−/− H9c2 cells. VDAC1−/− H9c2 cells also exhibited markedly reduced mitochondria-bound hexokinase II (HKII) and Bax. Restoration of VDAC1 in VDAC1−/− H9c2 cells reinstated mitochondria-bound HKII and concomitantly decreased tBHP and ROT-induced ROS production and cell death. Interestingly, mitochondrial respiration remained the same after tBHP treatment in VDAC1−/− and WT H9c2 cells.Conclusion:Our results suggest that VDAC1−/− in H9c2 cells enhances oxidative stress-mediated cell apoptosis that is directly linked to the reduction of mitochondria-bound HKII and concomitantly associated with enhanced ROS production, ECAR, and PPR.

Ellagic acid protects dopamine neurons from rotenone-induced neurotoxicity via activation of Nrf2 signalling.

Parkinson's disease (PD) is the second most prevalent central nervous system (CNS) degenerative disease. Oxidative stress is one of key contributors to PD. Nuclear factor erythroid‐2‐related factor 2 (Nrf2) is considered to be a master regulator of many genes involved in anti‐oxidant stress to attenuate cell death. Therefore, activation of Nrf2 signalling provides an effective avenue to treat PD. Ellagic acid (EA), a natural polyphenolic contained in fruits and nuts, possesses amounts of pharmacological activities, such as anti‐oxidant stress and anti‐inflammation. Recent studies have confirmed EA could be used as a neuroprotective agent in neurodegenerative diseases. Here, mice subcutaneous injection of rotenone (ROT)‐induced DA neuronal damage was performed to investigate EA‐mediated neuroprotection. In addition, adult Nrf2 knockout mice and different cell cultures including MN9D‐enciched, MN9D‐BV‐2 and MN9D‐C6 cell co‐cultures were applied to explore the underlying mechanisms. Results demonstrated EA conferred neuroprotection against ROT‐induced DA neurotoxicity. Activation of Nrf2 signalling was involved in EA‐mediated DA neuroprotection, as evidenced by the following observations. First, EA activated Nrf2 signalling in ROT‐induced DA neuronal damage. Second, EA generated neuroprotection with the presence of astroglia and silence of Nrf2 in astroglia abolished EA‐mediated neuroprotection. Third, EA failed to produce DA neuroprotection in Nrf2 knockout mice. In conclusion, this study identified EA protected against DA neuronal loss via an Nrf2‐dependent manner.

Prevention of algaculture contamination using pesticides for biofuel production

Compared to terrestrial biofuels, algal biofuels have the advantages of high areal productivity, high oil content and the ability to be cultivated using non-potable water on non-arable land. However, just like terrestrial agricultural crops, algae can be grazed by a wide variety of organisms, particularly in open pond systems. Algal grazers can be controlled using pesticides to make a more sustainable source of biofuels. In this study, we choose Chlorella kessleri as the model freshwater algal producer and select the freshwater rotifer, Brachionus calyciflorus and the freshwater ciliate, Colpoda sp. as the model algal grazers. The pesticides - quinine (QN), niclosamide (NC), 3-trifluoromethyl-4-nitrophenol (TFM), rotenone (ROT) and protons (pH) are used to inhibit algal grazers. C. kessleri is not affected by TFM and NC at concentrations up to 39 and 31 μM respectively, while inhibition of B. calyciflorus is achieved at concentrations of 18 and 14 μM respectively. Colpoda sp. is inhibited by NC at 8 μM, while, QN, TFM and ROT inhibit Colpoda sp. at 30 μM. A pH range between 8.4 and 10.3 inhibits B. calyciflorus and allows C. kessleri to grow well. Compared to previous results using ROT, the findings presented in this study demonstrate that algal grazers may be effectively controlled by using QN, NC and TFM yet may require higher doses than ROT.

Endoplasmic reticulum stress, unfolded protein response and autophagy contribute to resistance to glucocorticoid treatment in human acute lymphoblastic leukaemia cells.

Acute lymphoblastic leukaemia(ALL) is the most frequent childhood cancer and, although it is highly treatable, resistance to therapy, toxicity and side effects remain challenging. The synthetic glucocorticoid(GC) dexamethasone(Dex) is commonly used to treat ALL, the main drawback of which is the development of resistance to this treatment. The aim of the present study was to investigate potential molecular circuits mediating resistance and sensitivity to GC‑induced apoptosis in ALL. The leukaemia cell lines CEM‑C7‑14, CEM‑C1‑15 and MOLT4 treated with chloroquine(CLQ), thapsigargin(TG) and rotenone(ROT) were used to explore the roles of autophagy, endoplasmic reticulum(ER) stress/unfolded protein response(UPR) and reactive oxygen species(ROS) generation in the response to GC treatment. ROS levels were associated with increased cell death and mitochondrial membrane potential in rotenone‑treated CEM cells. Autophagy inhibition by CLQ exhibited the strongest cytotoxic effect in GC‑resistant leukaemia. Autophagy may act as a pro‑survival mechanism in GC‑resistant leukaemia since increasing trends in beclin‑1 and microtubule‑associated protein1 light chain3α levels were detected in CEM‑C1‑15 and MOLT4 cells treated with Dex, whereas decreasing trends in these autophagy markers were observed in CEM‑C7‑14 cells. The intracellular protein levels of the ER stress markers glucose‑regulated protein(GRP)78 and GRP94 were stimulated by Dex only in the GC‑sensitive cells, suggesting a role of these chaperones in the GC‑mediated ALL cell death. Increased cell surface levels of GRP94 were recorded in CEM‑C7‑14 cells treated with combination of Dex with TG compared with those in cells treated with TG alone, whereas decreasing trends were observed in CEM‑C1‑15 cells under these conditions. Taken together, the results of the present study demonstrated that autophagy may be a pro‑survival mechanism in GC‑resistant leukaemia, and by modulating intracellular and surface GRP94 protein levels, Dex is involved in the regulation of ER stress/UPR‑dependent cell death and immune surveillance. These observations may be of clinical importance if confirmed in patients.