Neuroprotective effect of geraniol and curcumin in an acrylamide model of neurotoxicity in Drosophila melanogaster: relevance to neuropathy

Dietary acrylamide disrupts the functioning of the biological clock

Acrylamide (ACR) is a known carcinogen and neurotoxin. It is chronically consumed in carbohydrate-rich snacks processed at high temperatures. This calls for systematic research into the effects of ACR intake, best performed in an experimental model capable of detecting symptoms of its neurotoxicity at both high and low doses. Here, we study the influence of 10 µg/g (corresponding to the concentrations found in food products) and, for comparison, 60, 80 and 110 µg/g dietary ACR, on the fruit fly Drosophila melanogaster. We show that chronic administration of ACR affects lifespan, activity level and, most importantly, the daily and circadian pattern of locomotor activity of Drosophila. ACR-treated flies show well-defined and concentration-dependent symptoms of ACR neurotoxicity; a reduced anticipation of upcoming changes in light conditions and increased arrhythmicity in constant darkness. The results suggest that the rhythm-generating neural circuits of their circadian oscillator (biological clock) are sensitive to ACR even at low concentrations if the exposure time is sufficiently long. This makes the behavioural readout of the clock, the rhythm of locomotor activity, a useful tool for studying the adverse effects of ACR and probably other compounds.

Novel acrylamide-based baits for effective control of subterranean termites (Blattodea: Rhinotermitidae)

BACKGROUND

Acrylamide-based bait has super water absorption making it highly attractive to subterranean termites that are lured by wood with high water content. This study investigated the control efficiency of these baits on subterranean termites. In particular, we evaluated the water-absorption capacity, attractiveness to subterranean termites, and control efficiency of these baits on subterranean termites through wooden blocks (Populus deltoides and three types of particleboards).

RESULTS

The results indicated a substantial water absorption capacity of acrylamide (70.6%; control: 14.8%) and a strong attraction for feeding subterranean termites (P. deltoides: 198 highest; 81 lowest subterranean termites individuals; combination of neem leaves and walnut shells: 168 highest; 36 lowest subterranean termites individuals). When acrylamide was combined with boric acid at the highest concentration, it resulted in the lowest wood consumption rates (P. deltoides: 24.1%; control: 63.8%, combination of neem leaves and walnut shells: 32.5%; control: 62.1%).

CONCLUSIONS

In conclusion, this research supports the commercial viability of employing innovative acrylamide-based toxic baits and particleboards for subterranean termite management. © 2024 Society of Chemical Industry.

Geraniol mitigates anxiety-like behaviors in rats by reducing oxidative stress, repairing impaired hippocampal neurotransmission, and normalizing brain cortical-EEG wave patterns after a single electric foot-shock exposure

Anxiety-like conditions can interfere with daily activities as the adaptive mechanism fails to cope with stress. These conditions are often linked with increased oxidative stress, and abrupt neurotransmission and electroencephalography (EEG) wave pattern. Geraniol, a monoterpenoid, has antioxidant and anti-inflammatory activities, as well as brain-calming effects. Therefore, in this study, geraniol was tested for the potential anxiolytic effects in a rat model of anxiety. The rats were exposed to an electric foot shock (1 mA for 1 s) to develop anxiety-like symptoms. Treatment was carried out using geraniol (10 and 30 mg/kg) and the standard diazepam drug. The behavior of the rats was analyzed using the open field test, light-dark test, and social interaction test. Afterward, the rats were decapitated to collect samples for neurochemical and biochemical analyses. The cortical-EEG wave pattern was also obtained. The study revealed that the electric foot shock induced anxiety-like symptoms, increased oxidative stress, and altered hippocampal neurotransmitter levels. The power of low-beta and high-beta was amplified with the increased coupling of delta-beta waves in anxiety group. However, the treatment with geraniol and diazepam normalized cortical-EEG wave pattern and hippocampal serotonin and catecholamines profile which was also reflected by reduced anxious behavior and normalized antioxidant levels. The study reports an anxiolytic potential of geraniol, which can be further explored in future.

Alcohol exacerbates psychosocial stress-induced neuropsychiatric symptoms: Attenuation by geraniol

Adaptation to psychosocial stress is psychologically distressing, initiating/promoting comorbidity with alcohol use disorders. Emerging evidence moreover showed that ethanol (EtOH) exacerbates social-defeat stress (SDS)-induced behavioral impairments, neurobiological sequelae, and poor therapeutic outcomes. Hence, this study investigated the effects of geraniol, an isoprenoid monoterpenoid alcohol with neuroprotective functions on EtOH escalated SDS-induced behavioral impairments, and neurobiological sequelae in mice. Male mice chronically exposed to SDS for 14 days were repeatedly fed with EtOH (2 g/kg, p. o.) from days 8-14. From days 1-14, SDS-EtOH co-exposed mice were concurrently treated with geraniol (25 and 50 mg/kg) or fluoxetine (10 mg/kg) orally. After SDS-EtOH translational interactions, arrays of behavioral tasks were examined, followed by investigations of oxido-inflammatory, neurochemicals levels, monoamine oxidase-B and acetylcholinesterase activities in the striatum, prefrontal-cortex, and hippocampus. The glial fibrillary acid protein (GFAP) expression was also quantified in the prefrontal-cortex immunohistochemically. Adrenal weights, serum glucose and corticosterone concentrations were measured. EtOH exacerbated SDS-induced low-stress resilience, social impairment characterized by anxiety, depression, and memory deficits were attenuated by geraniol (50 and 100 mg/kg) and fluoxetine. In line with this, geraniol increased the levels of dopamine, serotonin, and glutamic-acid decarboxylase enzyme, accompanied by reduced monoamine oxidase-B and acetylcholinesterase activities in the prefrontal-cortex, hippocampus, and striatum. Geraniol inhibited SDS-EtOH-induced adrenal hypertrophy, corticosterone, TNF-α, IL-6 release, malondialdehyde and nitrite levels, with increased antioxidant activities. Immunohistochemical analyses revealed that geraniol enhanced GFAP immunoreactivity in the prefrontal-cortex relative to SDS-EtOH group. We concluded that geraniol ameliorates SDS-EtOH interaction-induced behavioral changes via normalization of neuroimmune-endocrine and neurochemical dysregulations in mice brains.

Potential inhibitory effect of geraniol isolated from lemongrass (Cymbopogon commutatus Stapf) on tilmicosin-induced oxidative stress in cardiac tissue

An experimental study has been conducted to investigate the efficacy of geraniol (GNL) isolated from lemomgrass in protecting against cardiac toxicity induced by tilmicosin (TIL) in albino mice. Compared to TIL-treated mice, those supplemented with GNL had a thicker left ventricular wall and a smaller ventricular cavity. Studies of TIL animals treated with GNL showed that their cardiomyocytes had markedly changed in diameter and volume, along with a reduction in numerical density. After TIL induction, animals showed a significant increase in the protein expression of TGF-β1, TNF-α, nuclear factor kappa B (NF-kB), by 81.81, 73.75 and 66.67%, respectively, and hypertrophy marker proteins ANP, BNP, and calcineurin with respective percentages of 40, 33.34 and 42.34%. Interestingly, GNL significantly decreased the TGF-β1, TNF-α, NF-kB, ANP, BNP, and calcineurin levels by 60.94, 65.13, 52.37, 49.73, 44.18 and 36.84%, respectively. As observed from histopathology and Masson's trichrome staining, supplementation with GNL could rescue TIL-induced cardiac hypertrophy. According to these results, GNL may protect the heart by reducing hypertrophy in mice and modulating biomarkers of fibrosis and apoptosis.

Plant Monoterpenes and Essential Oils as Potential Anti-Ageing Agents: Insights from Preclinical Data

Ageing is a natural process characterized by a time-dependent decline of physiological integrity that compromises functionality and inevitably leads to death. This decline is also quite relevant in major human pathologies, being a primary risk factor in neurodegenerative diseases, metabolic disorders, cardiovascular diseases and musculoskeletal disorders. Bearing this in mind, it is not surprising that research aiming at improving human health during this process has burst in the last decades. Importantly, major hallmarks of the ageing process and phenotype have been identified, this knowledge being quite relevant for future studies towards the identification of putative pharmaceutical targets, enabling the development of preventive/therapeutic strategies to improve health and longevity. In this context, aromatic plants have emerged as a source of potential bioactive volatile molecules, mainly monoterpenes, with many studies referring to their anti-ageing potential. Nevertheless, an integrated review on the current knowledge is lacking, with several research approaches studying isolated ageing hallmarks or referring to an overall anti-ageing effect, without depicting possible mechanisms of action. Herein, we aim to provide an updated systematization of the bioactive potential of volatile monoterpenes on recently proposed ageing hallmarks, and highlight the main mechanisms of action already identified, as well as possible chemical entity-activity relations. By gathering and categorizing the available scattered information, we also aim to identify important research gaps that could help pave the way for future research in the field.

Geraniol protects hippocampal CA1 neurons and improves functional outcomes in global model of stroke in rats

Geraniol (GE), an acyclic monoterpene, is a chief constituent of essential oils of herbs and fruits. It possesses diverse pharmacological actions like antioxidant, anti-inflammatory, anti-apoptotic, and anti-parkinson. However, its neuroprotective potential in stroke is yet to be explored at large. The present study evaluated the neuroprotective potential of GE against the global model of cerebral ischemia/reperfusion (I/R)-injury in rats. Bilateral common carotid artery (BCCA) occlusion for 30 min followed by 7 days of reperfusion caused varied biochemical/enzymatic alterations viz. increase in levels of lipid peroxidation (LPO), nitric oxide (NO), xanthine oxidase (XO), and decrease in the levels of cerebroprotectives like superoxide dismutase (SOD), catalase (CAT), total thiols, and glutathione (GSH). GE-pretreatment markedly reversed these changes and restored the levels of protective enzymatic and non-enzymatic antioxidants near to normal compared to I/R group. Besides, GE treatment showed marked improvement in anxiety-related behavior and neuronal deficits in animals subjected to I/R injury. Moreover, 2,3,5-triphenyl tetrazolium chloride (TTC)-stained rat brain coronal sections and histopathological studies revealed neuronal protection against I/R-injury, as evidenced by a reduction in infarct area (%) and an increase in hippocampal CA1 neuronal density in the GE-treated groups. The results of this study revealed that GE exhibited potential neuroprotective activity by reducing oxidative stress and infarction area, and protecting hippocampal CA1 neurons against I/R-injury in the global stroke model in rats.

Geraniol improves passive avoidance memory and hippocampal synaptic plasticity deficits in a rat model of Alzheimer's disease

Alzheimer's disease (AD) is the most progressive and irreversible neurodegenerative disease that leads to synaptic loss and cognitive decline. The present study was designed to evaluate the effects of geraniol (GR), a valuable acyclic monoterpene alcohol, with protective and therapeutic effects, on passive avoidance memory, hippocampal synaptic plasticity, and amyloid-beta (Aβ) plaques formation in an AD rat model induced by intracerebroventricular (ICV) microinjection of Aβ_1-40. Seventy male Wistar rats were randomly into sham, control, control-GR (100 mg/kg; P.O. (orally), AD, GR-AD (100 mg/kg; P.O.; pretreatment), AD-GR (100 mg/kg; P.O.; treatment), and GR-AD-GR (100 mg/kg; P.O.; pretreatment & treatment). Administration of GR was continued for four consecutive weeks. Training for the passive avoidance test was carried out on the 36^th day and a memory retention test was performed 24 h later. On day 38, hippocampal synaptic plasticity (long-term potentiation; LTP) was recorded in perforant path-dentate gyrus (PP-DG) synapses to assess field excitatory postsynaptic potentials (fEPSPs) slope and population spike (PS) amplitude. Subsequently, Aβ plaques were identified in the hippocampus by Congo red staining. The results showed that Aβ microinjection increased passive avoidance memory impairment, suppressed of hippocampal LTP induction, and enhanced of Aβ plaque formation in the hippocampus. Interestingly, oral administration of GR improved passive avoidance memory deficit, ameliorated hippocampal LTP impairment, and reduced Aβ plaque accumulation in the Aβ-infused rats. The results suggest that GR mitigates Aβ-induced passive avoidance memory impairment, possibly through alleviation of hippocampal synaptic dysfunction and inhibition of Aβ plaque formation.

Acrylamide in food: Occurrence, metabolism, molecular toxicity mechanism and detoxification by phytochemicals

Acrylamide (ACR) is a common pollutant formed during food thermal processing such as frying, baking and roasting. ACR and its metabolites can cause various negative effects on organisms. To date, there have been some reviews summarizing the formation, absorption, detection and prevention of ACR, but there is no systematic summary on the mechanism of ACR-induced toxicity. In the past five years, the molecular mechanism for ACR-induced toxicity has been further explored and the detoxification of ACR by phytochemicals has been partly achieved. This review summarizes the ACR level in foods and its metabolic pathways, as well as highlights the mechanisms underlying ACR-induced toxicity and ACR detoxification by phytochemicals. It appears that oxidative stress, inflammation, apoptosis, autophagy, biochemical metabolism and gut microbiota disturbance are involved in various ACR-induced toxicities. In addition, the effects and possible action mechanisms of phytochemicals, including polyphenols, quinones, alkaloids, terpenoids, as well as vitamins and their analogs on ACR-induced toxicities are also discussed. This review provides potential therapeutic targets and strategies for addressing various ACR-induced toxicities in the future.

Amelioration of Age-Related Multiple Neuronal Impairments and Inflammation in High-Fat Diet-Fed Rats: The Prospective Multitargets of Geraniol

Neuroinflammation is documented to alter brain function as a consequence of metabolic changes linked with a high-fat diet (HFD). The primary target of this study is to see how geraniol is effective in manipulating age- and diet-associated multiple toxicity and neuroinflammation in HFD-fed rats. Sixty-four adult male Wistar rats were partitioned into two groups: Group 1 (untreated normal young and aged rats) and Group 2 (HFD-fed young and aged rats) that received HFD for 16 weeks before being orally treated with geraniol or chromax for eight weeks. The results revealed a dropping in proinflammatory cytokines (TNF-α and IL-6) and leptin while boosting adiponectin in geraniol-supplemented rats. The liver, kidney, and lipid profiles were improved in geraniol-HFD-treated groups. HFD-induced brain insulin resistance decreased insulin clearance and insulin-degrading enzyme (IDE) levels significantly after geraniol supplementation. Geraniol suppressed acetylcholinesterase (AChE) activity and alleviated oxidative stress by boosting neuronal reduced glutathione (GSH), catalase (CAT), glutathione-S-transferase (GST), and superoxide dismutase (SOD) activities. It lowered malondialdehyde concentration (TBARS), nitric oxide (NO), and xanthine oxidase (XO) and restored the structural damage to the brain tissue caused by HFD. Compared with model rats, geraniol boosted learning and memory function and ameliorated the inflammation status in the brain by lowering the protein levels of IL-1β, iNOS, NF-κBp65, and COX-2. In addition, the expression levels of inflammation-related genes (MCP-1, TNF-α, IL-6, IL-1β, and IDO-1) were lessened significantly. Remarkably, the supplementation of geraniol reversed the oxidative and inflammation changes associated with aging. It affected the redox status of young rats. In conclusion, our results exhibit the effectiveness of dietary geraniol supplementation in modifying age-related neuroinflammation and oxidative stress in rats and triggering off the use of geraniol as a noninvasive natural compound for controlling age- and diet-associated neuronal impairments and toxicity.

A systematic review on the effects of acrylamide and bisphenol A on the development of Drosophila melanogaster

The current global scenario has instigated a steady upsurge of synthetic chemicals usage thereby creating a toxic environment unsuitable for animals and humans. Acrylamide and bisphenol A are some of the most common toxins found in the atmosphere due to their extensive involvement in numerous industrial processes. Acrylamide, an occupational hazard toxin has been known to cause severe nerve damage and peripheral neuronal damage in both animals and humans. General sources of acrylamide exposure are effluents from textile and paper industries, cosmetics, and thermally processed foods rich in starch. Bisphenol A (BPA) is generally found in food packaging materials, dental sealants, and plastic bottles. It is highly temperature-sensitive that can easily leach into the food products or humans on contact. The genotoxic and neurotoxic effects of acrylamide and bisphenol A have been widely researched; however, more attention should be dedicated to understanding the developmental toxicity of these chemicals. The developmental impacts of toxin exposure can be easily understood using Drosophila melanogaster as a model given considering its short life span and genetic homology to humans. In this review, we have discussed the toxic effects of acrylamide and BPA on the developmental process of Drosophila melanogaster.

Bioactivity assessment of essential oils of Cymbopogon species using a network pharmacology approach

Essential oils of Cymbopogon species have wide commercial applications in fragrance, perfumery, and pharmaceuticals as they exhibit a horizon of bioactivities. Here, essential oils of C. flexuosus and C. martinii were analysed to identify bioactive constituents and bioactivities using a network pharmacology approach. Essential oils were isolated using hydro-distillation in a mini Clevenger apparatus. Analysis of essential oils by GC-MS revealed 20 and 15 chemical constituents in C. flexuosus and C. martinii, respectively. An ingredient-target protein-pathway network was constructed comprising 10 oil constituents (citral, geraniol, geranyl acetate, limonene, linalool, α-terpineol, borneol, α-pinene, myrcene, and n-decanol), 14 target proteins, 51 related pathways, and 108 connections. Analyses of the network showed geraniol, geranyl acetate, limonene, linalool, and citral as major active constituents. A core sub-network constructed from the ingredient-target protein-pathway network revealed bioactivities including anti-cancer, anti-inflammatory and neuroprotective. The protein association network pointed out the major target proteins viz., THRB, FXR, ALOX15, and TSHR and pathways like metabolic, and neuroactive ligand-receptor interaction pathways of essential oil constituents. The target proteins and pathways provided insights into the mechanism of action of bioactive constituents. Based on the results of the study, geraniol was correlated with neuroprotective, citral to chemo-preventive, and limonene to anti-inflammatory activities. Thus, the study offers a new way for the assessment of the bioactivities of Cymbopogon species essential oils leading to the development of new biomedicines.

Exploring the Binding Pattern of Geraniol with Acetylcholinesterase through In Silico Docking, Molecular Dynamics Simulation, and In Vitro Enzyme Inhibition Kinetics Studies

Acetylcholinesterase (AChE) inhibition is a key element in enhancing cholinergic transmission and subsequently relieving major symptoms of several neurological and neuromuscular disorders. Here, the inhibitory potential of geraniol and its mechanism of inhibition against AChE were elucidated in vitro and validated via an in silico study. Our in vitro enzyme inhibition kinetics results show that at increasing concentrations of geraniol and substrate, Vmax did not change significantly, but Km increased, which indicates that geraniol is a competitive inhibitor against AChE with an IC₅₀ value 98.06 ± 3.92 µM. All the parameters of the ADME study revealed that geraniol is an acceptable drug candidate. A docking study showed that the binding energy of geraniol (−5.6 kcal mol⁻¹) was lower than that of acetylcholine (−4.1 kcal mol⁻¹) with AChE, which exhibited around a 12.58-fold higher binding affinity of geraniol. Furthermore, molecular dynamics simulation revealed that the RMSD of AChE alone or in complex with geraniol fluctuated within acceptable limits throughout the simulation. The mean RMSF value of the complex ensures that the overall conformation of the protein remains conserved. The average values of Rg, MolSA, SASA, and PSA of the complex were 3.16 Å, 204.78, 9.13, and 51.58 Ų, respectively. We found that the total SSE of AChE in the complex was 38.84% (α-helix: 26.57% and β-sheets: 12.27%) and remained consistent throughout the simulation. These findings suggest that geraniol remained inside the binding cavity of AChE in a stable conformation. Further in vivo investigation is required to fully characterize the pharmacokinetic properties, optimization of dose administration, and efficacy of this plant-based natural compound.

Drosophila as an emerging model organism for studies of food-derived antioxidants

Dietary supplementation with antioxidants provides health benefits by preventing diseases caused by oxidative stress and damage. Consequently, there has been growing interest in the study of antioxidative foods and their active ingredients. Oxidative stress and antioxidative responses are mechanistically conserved from Drosophila to mammals. Therefore, as a well-established model organism with a short life cycle and advantages of genetic manipulation, the fruit fly has been increasingly employed to assess functions of antioxidants in vivo. In this review, the antioxidative defense mechanisms, methods used and assays developed in Drosophila to evaluate antioxidant supplementation, are highlighted. The main manifestations of antioxidation include reduction of reactive species, up-regulation of endogenous antioxidants, inhibition on oxidative damage to biomacromolecules, enhanced resistance against oxidative stress and extension of lifespan, which are related to the activations of nuclear factor erythroid 2-related factor 2-antioxidant response element pathway and other adaptive responses. Moreover, the key considerations and future perspectives for the application of Drosophila models in the studies of food-derived antioxidants are discussed.

Acrylamide-induced peripheral neuropathy: manifestations, mechanisms, and potential treatment modalities

Acrylamide is a chemical monomer; its polymer compounds are used in the manufacture of plastic, papers, adhesive tapes, dyes, and food packaging. Lately, scientists found that cooking (mainly roasting, baking, and frying) yields acrylamide. In addition to fried/baked potatoes, coffee and bakery products still contain substantial amounts of acrylamide. Acrylamide has toxic effects on different body systems include genitourinary, reproductive, nervous system, along with being a carcinogenic substance. The neurotoxicity of acrylamide includes central and peripheral neuropathy. In humans, the clinical manifestations include sensory or motor peripheral neuropathy, drowsiness, or cerebellar ataxia. Likewise, it presents with skeletal muscle weakness, hindlimb dysfunction, ataxia, and weight loss in animals. The suggested mechanisms for acrylamide neurotoxicity include direct inhibition of neurotransmission, cellular changes, inhibition of key cellular enzymes, and bonding of kinesin-based fast axonal transport. Moreover, it is suggested that acrylamide's molecular effect on SNARE core kinetics is carried out through the adduction of NSF and/or SNARE proteins. Lately, scientists showed disruption of focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2) cell signaling pathways in human differentiating neuroblastoma SH-SY5Y cells, exposed to acrylamide. Different treatment modalities have been revealed to shield against or hasten recovery from acrylamide-induced neuropathy in preclinical studies, including phytochemical, biological, and vitamin-based compounds. Still, additional studies are needed to elucidate the pathogenesis and to identify the best treatment modality.

Assessing the influence of curcumin in sex-specific oxidative stress, survival and behavior in Drosophila melanogaster

Oxidative stress, which occurs from an imbalance of reactive oxygen and nitrogen species (RONS) and both endogenous and exogenous antioxidants, promotes aging and underlies sex-specific differences in longevity and susceptibility to age-related neurodegeneration. Recent evidence suggests that curcumin, a yellow pigment derived from turmeric and shown to exhibit antioxidant properties as a RONS scavenger, influences the regulation of genetic elements in endogenous antioxidant pathways. To investigate the role of curcumin in sex-specific in vivo responses to oxidative stress, Drosophila were reared on media supplemented with 0.25, 2.5 or 25 mmol l-1 curcuminoids (consisting of curcumin, demethoxycurcumin and bisdemethoxycurcumin) and resistance to oxidative stress and neural parameters were assessed. High levels of curcuminoids exhibited two sex-specific effects: protection from hydrogen peroxide as an oxidative stressor and alterations in turning rate in an open field. Taken together, these results suggest that the influence of curcuminoids as antioxidants probably relies on changes in gene expression and that sexual dimorphism exists in the in vivo response to curcuminoids.

The anti-apoptotic, antioxidant and anti-inflammatory effects of curcumin on acrylamide-induced neurotoxicity in rats

Background

Acrylamide (ACR) formed during heating of tobacco and carbohydrate-rich food as well as widely applied in industries has been known as a well-established neurotoxic pollutant. Although the precise mechanism is unclear, enhanced apoptosis, oxidative stress and inflammation have been demonstrated to contribute to the ACR-induced neurotoxicity. In this study, we assessed the possible anti-apoptotic, antioxidant and anti-inflammatory effects of curcumin, the most active component in a popular spice known as turmeric, on the neurotoxicity caused by ACR in rats.

Methods

Curcumin at the dose of 50 and 100 mg/kg was orally given to ACR- intoxicated Sprague-Dawley rats exposed by ACR at 40 mg/kg for 4 weeks. All rats were subjected to behavioral analysis. The HE staining and terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) staining were used to detect histopathological changes and apoptotic cells, respectively. The mRNA and protein expressions of apoptosis-related molecule telomerase reverse transcriptase (TERT) were detected using real-time PCR and immunohistochemistry, respectively. The contents of malondialdehyde (MDA) and glutathione (GSH) as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured as the indicators for evaluating the level of oxidative stress in brain. The levels of pro-inflammatory cytokinestumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the cerebral homogenates were detected using ELISA assay.

Results

ACR-induced weigh loss, deficits in motor function as well as pathological alterations in brains were significantly improved in rats administrated with 50 and 100 mg/kg curcumin. TUNEL-positive apoptotic cells in curcumin-treated ACR intoxicated brains were less than those in the ACR model group. Curcumin administration especially at the dose of 100 mg/kg upregulated the TERT mRNA expression and enhanced the number of TERT-positive cells in ACR-intoxicated cortex tissues. Moreover, curcumin treatment reduced the concentrations of TNF-α, IL-1β and MDA, while increased the GSH contents as well as the SOD and GSH-Px activities in the cerebral homogenates, in comparison to ACR control group.

Conclusions

These data suggested the anti-apoptotic, antioxidant and anti-inflammatory effects of curcumin on ACR-induced neurotoxicity in rats. Maintaining TERT-related anti-apoptotic function might be one mechanism underlying the protective effect of curcumin on ACR-intoxicated brains.

Developmental and behavioural toxicity induced by acrylamide exposure and amelioration using phytochemicals in Drosophila melanogaster

Acrylamide, an environmental pollutant, is known to occur in food substances cooked at high temperatures. Studies on various models indicate acrylamide to cause several physiological conditions such as neuro- and reproductive toxicity, and carcinogenesis. In our study, exposure of Drosophila melanogaster (Oregon K strain) to acrylamide via their diet resulted in a concentration and time-dependent mortality, while the surviving flies exhibited significant locomotor deficits, most likely due to oxidative stress-induced neuronal damage. Also, Drosophila embryos exhibited signs of developmental toxicity as evidenced by the alteration in the migration of border cells and cluster cells during the developmental stages, concomitant to modulation in expression of gurken and oskar genes. Curcumin, a known antioxidant has been widely studied for its neuroprotective effects against acrylamide; however; very few studies focus on thymoquinone for its role against food toxicant. Our research focuses on the toxicity elicited by acrylamide and the ability of the antioxidants: thymoquinone, curcumin and combination of thereof, in reversing the same.

Neuroprotective effect of diosgenin in a mouse model of diabetic peripheral neuropathy involves the Nrf2/HO-1 pathway

Background

Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes. Diosgenin is a natural steroidal saponin with a variety of beneficial effects, including antidiabetic effects, and is a raw material for the synthesis of carrier hormones. In our study, we aimed to assess the antioxidant effects of diosgenin in diabetic mice.

Methods

Male C57 mice were fed a high-fat diet for 8 weeks and intraperitoneally injected with streptozotocin (STZ) at a dose of 100 mg/kg for 2 consecutive days. Eligible mice were divided into the normal control group (CON), diabetic group (DM), low-dose diosgenin (50 mg/kg) group (DIO50) and high-dose diosgenin (100 mg/kg) group (DIO100). Treatment was started 6 weeks after the induction of diabetes by STZ and continued for 8 weeks. Blood sugar and body weight were monitored dynamically. The behavioural effects of diosgenin were detected by a hot tail immersion test and paw tactile responses. HE staining was used to evaluate edema and degeneration of the sciatic nerve. The levels of SOD, MDA and GPx were tested according to the instructions of the respective kits. The levels of Nrf2, HO-1 and NQO1 were detected by immunofluorescence and Western blotting. Statistical analysis was performed using SPSS, and P < 0.05 was considered statistically significant.

Results

Diosgenin decreased the blood glucose levels and increased the body weight of diabetic mice. There was a significant increase in the tail withdrawal latency of diabetic animals, and mechanical hyperalgesia was significantly alleviated after diosgenin treatment. Histopathological micrographs of HE-stained sciatic nerves showed improvement after diosgenin treatment. Diosgenin attenuated the level of MDA but increased the activities of SOD and GPx. Diosgenin increased the expression of Nrf2, HO-1 and NQO1.

Conclusions

Our results demonstrate that diosgenin can ameliorate behavioural and morphological changes in DPN by reducing oxidative stress. The Nrf2/HO-1 signalling pathway was involved in its neuroprotective effects.

Mesenchymal stem cells in chemotherapy-induced peripheral neuropathy: A new challenging approach that requires further investigations

Chemotherapeutic drugs may disrupt the nervous system and cause chemotherapy-induced peripheral neuropathy (CIPN) as side effects. There are no completely successful medications for the prevention or treatment of CIPN. Many drugs such as tricyclic antidepressants and anticonvulsants have been used for symptomatic treatment of CIPN. Unfortunately, these drugs often give only partial relief or have dose-limiting side effects. Thus, the treatment of CIPN becomes a challenge because of failure to regenerate and repair the injured neurons. Mesenchymal stem cell (MSC) therapy is a new attractive approach for CIPN. Evidence has demonstrated that MSCs play important roles in reducing oxidative stress, neuroinflammation, and apoptosis, as well as mediating axon regeneration after nerve damage in several experimental studies and some clinical trials. We will briefly review the pathogenesis of CIPN, traditional therapies used and their drawbacks as well as therapeutic effects of MSCs, their related mechanisms, future challenges for their clinical application, and the additional benefit of their combination with pharmacological agents. MSCs-based therapies may provide a new therapeutic strategy for patients suffering from CIPN where further investigations are required for studying their exact mechanisms. Combined therapy with pharmacological agents can provide another promising option for enhancing MSC therapy success while limiting its adverse effects.

Dose-dependent chemopreventive effects of citronellol in DMBA-induced breast cancer among rats

Breast cancer is one of the most common cancers among women world wide and its incidence is on tremendous increase. The present study is aimed to analyze the dose-dependent chemopreventive efficacy of citronellol on 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary carcinogenesis. The mammary tumor was induced through a single dose of DMBA (25 mg/rat) injected subcutaneously near the mammary gland of rats. In DMBA-injected rats, 100% tumor incidence, increased tumor volume, and tumor burden along with loss of body weight were observed. Biochemical analysis revealed the increased levels of phase I detoxification proteins (cytochrome P450 and b5) and decreased activities of phase II detoxification enzymes (glutathione-S-transferase and glutathione reductase) in hepatic and mammary tissues. The levels of enzymatic and non-enzymatic antioxidants (superoxidedismutase, catalase, glutathione peroxidase, and (GPx) and reduced glutathione) were decreased and lipid peroxidation by-products (thiobarbituric acid reactive substance and lipid hydroperoxide) got increased in plasma and mammary tissues. Oral administration of different doses of citronellol (25, 50, and 100 mg/kg body weight) to DMBA-treated rats for 16 weeks absolutely inhibited the tumor incidence and restored the biochemical parameters near to normal level in 50 and 100 mg doses whereas the histopathological studies also supported the biochemical findings. Hence, the result suggests that the citronellol of 50 mg/kg body weight exerted significant chemopreventive effects and can be considered as a minimum optimum dose in the prevention of mammary carcinogenesis.

In vitro and in vivo evaluation of enzymatic and antioxidant activity, cytotoxicity and genotoxicity of curcumin-loaded solid dispersions

Curcumin, the main bioactive polyphenolic compound in Curcuma longa L. rhizomes has a wide range of bioactive properties. Curcumin presents low solubility in water and thus limited bioavailability, which decreases its applicability. In this study, cytotoxic effects of curcumin solid dispersions (CurSD) were evaluated against tumor (breast adenocarcinoma and lung, cervical and hepatocellular carcinoma) and non-tumor (PLP2) cells, while cytotoxic and genotoxic effects were evaluated in Allium cepa. The effect of the CurSD on the acetylcholinesterase (AChE), butyrylcholinesterase (BChE), glutathione S-transferase (GST), and monoamine oxidase (MAO A-B) enzymes was determined, as well as its capacity to inhibit the oxidative hemolysis (OxHLIA) and the formation of thiobarbituric acid reactive substances (TBARS). CurSD are constituted by nanoparticles that are readily dispersible in water, and inhibited 24% and 64% of the AChE and BChE activity at 100 μM, respectively. GST activity was inhibited at 30 μM while MAO-A and B activity were inhibited at 100 μM. CurSD showed cytotoxicity against all the tested tumor cell lines without toxic effects for non-tumor cells. No cytotoxic and genotoxic potential was detected with the Allium cepa test. CurSD maintained the characteristics of free curcumin on the in vitro modulation of important enzymes without appreciable toxicity.

Study of nuclear factor-2 erythroid related factor-2 activator, berberine, in paclitaxel induced peripheral neuropathy pain model in rats

OBJECTIVES

The role of nuclear factor-2 erythroid related factor-2 (Nrf2) activator, berberine (BBR), has been established in rat model of streptozotocin induced diabetic neuropathy. Around 30-40% of cancer patients, on paclitaxel (PTX) chemotherapy develop peripheral neuropathy. The present study was contemplated with the aim of establishing the neuropathy preventive role of BBR, in paclitaxel induced peripheral neuropathy model in rats.

METHODS

A total of 30 Wistar rats were divided into five groups as follows: Group I: dimethyl sulfoxide; Group II: PTX+ 0.9% NaCl; Group III: Amitriptyline (ATL) + PTX; Group IV: BBR (10 mg/kg) + PTX and Group V: BBR (20 mg/kg) + PTX. Animals were assessed for tail flick latency, tail cold allodynia latency, histopathological scores, oxidative stress parameters, and mRNA expression of the Nrf2 gene in the sciatic nerve.

KEY FINDINGS

Berberine significantly increased the tail flick and tail cold allodynia latencies and significantly decreased the histopathological score. BBR reduced oxidative stress by significantly decreasing the lipid peroxidation, increasing the superoxide dismutase and reduced glutathione levels in the sciatic nerve. BBR also increased the mRNA expression of Nrf2 gene in rat sciatic nerve.

CONCLUSIONS

All of these results showed the neuropathy preventing role of BBR in PTX induced neuropathy pain model in rats.

Depressant effect of geraniol on the central nervous system of rats: Behavior and ECoG power spectra

Geraniol is a monoterpene alcohol that is derived from the essential oils of aromatic plants, with anti-inflammatory, antimicrobial, antioxidant and neuroprotective properties. This study characterized the effect of geraniol on behavior and brainwave patterns in rats. Male rats were submitted to administration of geraniol (25, 50 and 100 mg/kg). The hole board (HB) and open field (OF) tests were performed to evaluate anxiety and motor behavior, respectively. In addition, barbiturate-induced sleeping time (BIST) was used to analyze sedative effect. Finally, electrocorticogram (ECoG) recordings were used to characterize brain-wave patterns. The results showed that geraniol treatment in rats decreased the distance traveled, rearing numbers and lead to increase in immobility time in HB and OF tests. In BIST test, geraniol treatment increased sleep duration but not sleep latency in the animals. Furthermore, geraniol-treated animals demonstrated an increase in the percentage of delta waves in the total spectrum power. Taken together, our results suggested that geraniol exerted a depressant effect on the central nervous system of rats.

Geraniol Protects Against the Protein and Oxidative Stress Induced by Rotenone in an In Vitro Model of Parkinson's Disease

Dysfunction of autophagy, mitochondrial dynamics and endoplasmic reticulum (ER) stress are currently considered as major contributing factors in the pathogenesis of Parkinson's disease (PD). Accumulation of oxidatively damaged cytoplasmic organelles and unfolded proteins in the lumen of the ER causes ER stress and it is associated with dopaminergic cell death in PD. Rotenone is a pesticide that selectively kills dopaminergic neurons by a variety of mechanism, has been implicated in PD. Geraniol (GE; 3,7-dimethylocta-trans-2,6-dien-1-ol) is an acyclic monoterpene alcohol occurring in the essential oils of several aromatic plants. In this study, we investigated the protective effect of GE on rotenone-induced mitochondrial dysfunction dependent oxidative stress leads to cell death in SK-N-SH cells. In addition, we assessed the involvement of GE on rotenone-induced dysfunction in autophagy machinery via α-synuclein accumulation induced ER stress. We found that pre-treatment of GE enhanced cell viability, ameliorated intracellular redox, preserved mitochondrial membrane potential and improves the level of mitochondrial complex-1 in rotenone treated SK-N-SH cells. Furthermore, GE diminishes autophagy flux by reduced autophagy markers, and decreases ER stress by reducing α-synuclein expression in SK-N-SH cells. Our results demonstrate that GE possess its neuroprotective effect via reduced rotenone-induced oxidative stress by enhanced antioxidant status and maintain mitochondrial function. Furthermore, GE reduced ER stress and improved autophagy flux in the neuroblastomal SK-N-SH cells. The present study could suggest that GE a novel therapeutic avenue for clinical intervention in neurodegenerative diseases especially for PD.

Design, synthesis and X-ray crystallography of selenides bearing benzenesulfonamide moiety with neuropathic pain modulating effects

A series of selenides bearing benzensulfonamide were investigated as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). Potent inhibitory action, in the low nanomolar range, was detected against isoforms hCA II and VII, which are known to be involved in neuropathic pain modulation. These selenides showed on the other hand moderate inhibition against the cytosolic isoforms hCA I and transmembrane hCA IX. X-ray crystallographic data of two derivatives bound to hCA II allowed us to rationalize the excellent inhibitory data. In a mice model of neuropathic pain induced by oxaliplatin, some of the strong CA II/VII inhibitors induced a long lasting pain relieving effect.

Cerium oxide nanoparticles protects against acrylamide induced toxicity in HepG2 cells through modulation of oxidative stress

Acrylamide (AA) is a toxic chemical compound found in cooked foods. Considerable evidences suggest that oxidative stress and mitochondrial dysfunction are contributed to AA toxicity. Ceric oxide (CeO₂) nanoparticles (nano-ceria) have the potential to be developed as a therapeutic for oxidative stress insults due to their catalytic antioxidant properties. In this study we investigated, whether nano-ceria exerted a protective effect against AA-induced cytotoxicity and oxidative damage. HepG2 human cancer cell lines were exposed to nano-ceria (50, 100, and 200 µM) and after 30 min, AA in the half maximal inhibitory concentration (IC50) concentration (200 µM) was added to the cells. Twenty four hours later, cellular viability, reactive oxygen species (ROS) generation, lipid peroxidation (LPO), and cellular levels of glutathione (GSH) were assayed. AA decreased cell viability and pretreatment with nano-ceria significantly decreased AA-induced cytotoxicity. In addition, nano-ceria alleviated AA-induced ROS generation and LPO and depressed GSH level. Our results suggested that nano-ceria prevented cellular and oxidative damage induced by AA.

Analysis of the main active ingredients and bioactivities of essential oil from Osmanthus fragrans Var. thunbergii using a complex network approach

BACKGROUND

Osmanthus fragrans has been used as folk medicine for thousands of years. The extracts of Osmanthus fragrans flowers were reported to have various bioactivities including free radical scavenging, anti-inflammation, neuroprotection and antitumor effects. However, there is still lack of knowledge about its essential oil.

METHODS

In this work, we analyzed the chemical composition of the essential oil from Osmanthus fragrans var. thunbergii by GC-MS. A complex network approach was applied to investigate the interrelationships between the ingredients, target proteins, and related pathways for the essential oil. Statistical characteristics of the networks were further studied to explore the main active ingredients and potential bioactivities of O. fragrans var. thunbergii essential oil.

RESULTS

A total of 44 ingredients were selected from the chemical composition of O. fragrans var. thunbergii essential oil, and that 191 potential target proteins together with 70 pathways were collected for these compounds. An ingredient-target-pathway network was constructed based on these data and showed scale-free property as well as power-law degree distribution. Eugenol and geraniol were screened as main active ingredients with much higher degree values. Potential neuroprotective and anti-tumor effect of the essential oil were also found. A core subnetwork was extracted from the ingredient-target-pathway network, and indicated that eugenol and geraniol contributed most to the neuroprotection of this essential oil. Furthermore, a pathway-based protein association network was built and exhibited small-world property. MAPK1 and MAPK3 were considered as key proteins with highest scores of centrality indices, which might play an important role in the anti-tumor effect of the essential oil.

CONCLUSIONS

This work predicted the main active ingredients and bioactivities of O. fragrans var. thunbergii essential oil, which would benefit the development and utilization of Osmanthus fragrans flowers. The application of complex network theory was proved to be effective in bioactivities studies of essential oil. Moreover, it provides a novel strategy for exploring the molecular mechanisms of traditional medicines.

Neurotoxicity of fragrance compounds: A review

Fragrance compounds are chemicals belonging to one of several families, which are used frequently and globally in cosmetics, household products, foods and beverages. A complete list of such compounds is rarely found on the ingredients-list of such products, as "fragrance mixtures" are defined as "trade secrets" and thus protected by law. While some information regarding the general toxicity of some of these compounds is available, their neurotoxicity is known to a lesser extent. Here, we discuss the prevalence and neurotoxicity of fragrance compounds belonging to the three most common groups: phthalates, synthetic musks and chemical sensitizers.

Alteration in biochemical parameters in the brain of transgenic Drosophila melanogaster model of Parkinson's disease exposed to apigenin

BACKGROUND

Oxidative stress is one of the key components of the pathology of various neurodegenerative disorders. Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons owing to the aggregation of alpha-synuclein (αS) in the brain. A number of polyphenols have been reported to inhibit the αS aggregation resulting in the possible prevention of PD. The involvement of free radicals in mediating the neuronal death in PD has also been implicated.

METHODS

In the present study, the transgenic flies expressing human αS in the brain were exposed to 10 μM, 20 μM, 40 μM, and 80 μM of apigenin established in diet for 24 days.

RESULTS

The flies showed an increase in life span, glutathione, and dopamine content. The exposure of PD flies to various doses of apigenin also results in the reduction of glutathione-S-transferase activity, lipid peroxidation, monoamine oxidase, caspase-3, and caspase-9 activity in a dose-dependent manner.

CONCLUSION

The results of the present study reveal that apigenin is potent in increasing the life span, dopamine content, reduced the oxidative stress as well as apoptosis in transgenic Drosophila model of PD.

Monoterpenes as a renewable source of biologically active compounds

Monoterpenes and their derivatives play an important role in the creation of new biologically active compounds including drugs. The review focuses on the data on various types of biological activity exhibited by monoterpenes and their derivatives, including analgesic, anti-inflammatory, anticonvulsant, antidepressant, anti-Alzheimer, anti-Parkinsonian, antiviral, and antibacterial (anti-tuberculosis) effects. Searching for novel potential drugs among monoterpene derivatives shows great promise for treating various pathologies. Special attention is paid to the effect of absolute configuration of monoterpenes and monoterpenoids on their activity.

Acrylamide-induced neurotoxicity in primary astrocytes and microglia: Roles of the Nrf2-ARE and NF-κB pathways

Acrylamide (AA) is a common food contaminant formed during food heat processing that has neurotoxic effects. We hypothesize that AA induces oxidative stress in astrocytes and microglia, leading to neurotoxicity. Oxidative status, translocation of Nrf2 and NF-κB, and related down-stream targets were measured in primary astrocytes and microglia obtained from BALB/c mice. The results showed that AA increased reactive oxygen species (ROS) formation and reduced glutathione levels, causing successive events associated with oxidative stress, including 4-hydroxynonenal and 8-hydroxy-2-deoxyguanosine adduct formation, in both cell types. Both Nrf2 and NF-κB pathways were activated, but Nrf2 and its downstream antioxidative genes acted at earlier stages in both cell types before NF-κB activation. After NF-κB activation, related cytokines, including IL-6, TNF-α, G-CSF, and IL-1β, were released and cell viability decreased. Greater ROS generation, faster glutathione reduction, and increased oxidative adduct formation were observed in microglia compared with astrocytes. Moreover, Nrf2/NF-κB and its downstream genes were up-regulated much faster and to greater degrees in microglia than astrocytes. These results clarify the roles of the Nrf2 and NF-κB pathways in AA-induced neurotoxicity. These cellular responses may provide new insights for the development of adverse outcome pathway approaches for risk assessments of AA.

Toxicological Implications of Mitochondrial Localization of CYP2E1

Cytochrome P450 2E1 (CYP2E1) metabolizes an extensive array of pollutants, drugs, and other small molecules, often resulting in bioactivation to reactive metabolites. Therefore, it is unsurprising that it has been the subject of decades of research publications and reviews. However, while CYP2E1 has historically been studied in the endoplasmic reticulum (erCYP2E1), active CYP2E1 is also present in mitochondria (mtCYP2E1). Relatively few studies have specifically focused on mtCYP2E1, but there is growing interest in this form of the enzyme as a driver in toxicological mechanisms given its activity and location. Many previous studies have linked total CYP2E1 to conditions that involve mitochondrial dysfunction (fasting, diabetes, non-alcoholic steatohepatitis, and obesity). Furthermore, a large number of reactive metabolites that are formed by CYP2E1 through metabolism of drugs and pollutants have been demonstrated to cause mitochondrial dysfunction. Finally, there appears to be significant inter-individual variability in targeting to the mitochondria, which could constitute a source of variability in individual response to exposures. This review discusses those outcomes, the biochemical properties and toxicological consequences of mtCYP2E1, and highlights important knowledge gaps and future directions. Overall, we feel that this exciting area of research is rich with new and important questions about the relationship between mtCYP2E1, mitochondrial dysfunction, and pathology.

1,3-Butadiene-induced mitochondrial dysfunction is correlated with mitochondrial CYP2E1 activity in Collaborative Cross mice

Cytochrome P450 2E1 (CYP2E1) metabolizes low molecular weight hydrophobic compounds, including 1,3-butadiene, which is converted by CYP2E1 to electrophilic epoxide metabolites that covalently modify cellular proteins and DNA. Previous CYP2E1 studies have mainly focused on the enzyme localized in the endoplasmic reticulum (erCYP2E1); however, active CYP2E1 has also been found in mitochondria (mtCYP2E1) and the distribution of CYP2E1 between organelles can influence an individual's response to exposure. Relatively few studies have focused on the contribution of mtCYP2E1 to activation of chemical toxicants. We hypothesized that CYP2E1 bioactivation of 1,3-butadiene within mitochondria adversely affects mitochondrial respiratory complexes I-IV. A population of Collaborative Cross mice was exposed to air (control) or 200ppm 1,3-butadiene. Subcellular fractions (mitochondria, DNA, and microsomes) were collected from frozen livers and CYP2E1 activity was measured in microsomes and mitochondria. Individual activities of mitochondrial respiratory complexes I-IV were measured using in vitro assays and purified mitochondrial fractions. In air- and 1,3-butadiene-exposed mouse samples, mtDNA copy numbers were assessed by RT-PCR, and mtDNA integrity was assessed through a PCR-based assay. No significant changes in mtDNA copy number or integrity were observed; however, there was a decrease in overall activity of mitochondrial respiratory complexes I, II, and IV after 1,3-butadiene exposure. Additionally, higher mtCYP2E1 (but not erCYP2E1) activity was correlated with decreased mitochondrial respiratory complex activity (in complexes I-IV) in the 1,3-butadiene-exposed (not control) animals. Together, these results represent the first in vivo link between mitochondrial CYP2E1 activity and mitochondrial toxicity.

Influence of Quercetin in the Temporal Regulation of Redox Homeostasis in Drosophila melanogaster

Numerous biological processes are governed by the biological clock. Studies using Drosophila melanogaster (L.) are valuable that could be of importance for their effective applications on rodent studies. In this study, the beneficial role of quercetin (a flavonoid) on H2O2 induced stress in D. melanogaster was investigated. D. melanogaster flies were divided into four groups (group I - control, group II - H2O2 (acute exposure), group III - quercetin, and group IV - quercetin + H2O2 treated). Negative geotaxis assay, oxidative stress indicators (protein carbonyls, thiobarbituric reactive substances [TBARS]), and antioxidants (superoxide dismutase [SOD], catalase [CAT], glutathione-S-transferase [GST], glutathione peroxidase, and reduced glutathione [GSH]) were measured at 4 h intervals over 24 h and temporal expression of heat shock protein-70 (Hsp70), Upd1 (homolog of IL-6 in Drosophila), and nitric oxide synthase (Nos) was analyzed by Western blotting. Groups II and IV showed altered biochemical rhythms (compared with controls). Decreased mesor values of negative geotaxis, SOD, CAT, GST, and GSH were noticed in H2O2, increased mesor of oxidative stress indicators (TBARS and protein carbonyl content) and a reversibility of the rhythmic characteristics were conspicuous after quercetin treatment. The expression levels of Hsp70, Upd1, and Nos were noticeably maximum at 04:00. Significant elevation of expression by H2O2 was nearly normalized by quercetin treatment. The possible mechanism by which quercetin modulates oxidant-antioxidant imbalance under oxidative stress could be ascribed to the modulation of the rhythmic properties. Our results will be helpful to understand the molecular interlink between circadian rhythm and oxidative stress mechanism.

Protective effect of Geraniol on the transgenic Drosophila model of Parkinson's disease

The role of Geraniol was studied on the transgenic Drosophila model flies expressing normal human alpha synuclein (h-αS) in the neurons. Geraniol at final concentration of 10, 20 and 40μM were mixed in the diet and the flies were allowed to feed on it for 24 days. The effect of geraniol was studied on the climbing ability, activity pattern, lipid peroxidation, protein carbonyl, glutathione, dopamine content, and glutathione-S-transferase activity in the brains of transgenic Drosophila. The exposure of PD model flies to 10, 20 and 40μM of geraniol results in a significant delay in the loss of climbing ability (p<0.05), improved activity pattern reduced the oxidative stress (p<0.05) in the brains of transgenic Drosophila as compared to unexposed PD model flies. The results suggest that geraniol is potent in reducing the PD symptoms in transgenic Drosophila model of Parkinson's disease.

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

A review of the interactions between acrylamide, microorganisms and food components

Acrylamide (AA) and its metabolites have been recognized as potential carcinogens, but also they can cause other negative symptoms in human or animal organisms and therefore this class of chemical compounds has attracted a lot of attention.

Geraniol produces antidepressant-like effects in a chronic unpredictable mild stress mice model

Geraniol (GE), which has neuroprotection and anti-inflammation activities, is mostly abundant in the essential oils of rose, ginger, lemon, orange, lavender etc. However, its antidepressant-like effect has not been reported before. The present study was designed to investigate whether GE confers an antidepressant effect in mice exposed to a chronic unpredictable mild stress (CUMS) model of depression and to explore its possible mechanisms. The results showed that GE treatments for 3 weeks significantly alleviated the depression-related behaviors of CUMS-exposed mice, as indicated by restored decreased sucrose preference and shortened immobile time in both the forced swimming tests (FST) and tail suspension tests (TST). And these ameliorative effects of GE treatment were involved with regulating CUMS-induced pro-inflammatory cytokine interleukin-1 beta (IL-1β) related neuro-inflammation. We further found that GE treatment reversed CUMS-induced IL-1β elevation, possibly by inhibiting nuclear factor kappa B (NF-κB) pathway activation and regulating nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome expression. Taken together, our findings suggested that GE exerted a potential antidepressant-like effect in CUMS mice model of depression, which may provide an insight into the potential of GE in therapeutic implications for depression.

The Potential for Plant Derivatives against Acrylamide Neurotoxicity

Certain industrial chemicals and food contaminants have been demonstrated to possess neurotoxic activity and have been suspected to cause brain-related disorders in humans. Acrylamide (ACR), a confirmed neurotoxicant, can be found in trace amount in commonly consumed human aliments as a result of food processing or cooking. This discovery aroused a great concern in the public, and increasing efforts are continuously geared towards the resolution of this serious threat. The broad chemical diversity of plants may offer the resources for novel antidotes against neurotoxicants. With the goal of attenuating neurotoxicity of ACR, several plants extracts or derivatives have been employed. This review presents the plants and their derivatives that have been shown most active against ACR-induced neurotoxicity, with a focus on their origin, pharmacological activity, and antidote effects.

Role of antioxidants and phytochemicals on acrylamide mitigation from food and reducing its toxicity

Nowadays, the presence of acrylamide in lots of fried and baked foods raises concerns due to its potential to cause toxicity and cancer in animals and human. Consequently, a number of papers have focused on evaluation of various chemicals in reduction of acrylamide in various food sources, as well as decreasing its related toxicities. In addition, plants are important sources of diverse metabolites demonstrating either possible effectiveness in acrylamide toxicity or reduction of acrylamide content in food sources. In this paper, we have criticized all relevant studies in terms of acrylamide mitigation from food by phytochemicals and antioxidants, and the influence of herbal medicines and phyto-pharmaceuticals on reduction of acrylamide toxicity in both animals and human.