Carvacrol reduces hippocampal cell death and improves learning and memory deficits following lead-induced neurotoxicity via antioxidant activity

Neuroprotective potential of carvacrol: restoration of oxidative balance and mitigation of brain injury markers in isoproterenol-induced rats

This research investigated the protective properties of Carvacrol (CVC) against Isoproterenol (ISO)-induced oxidative stress, neuroinflammation, and mitochondrial dysfunction in rats. The findings showed that CVC treatment did not significantly modify baseline oxidative stress levels in healthy rats but successfully alleviated ISO-induced oxidative damage by augmenting antioxidant enzyme activity and diminishing lipid peroxidation, as demonstrated by a reduction in MDA levels. These findings indicate that CVC can reinstate antioxidant capability and reduce oxidative damage. Concerning neuroinflammation, ISO therapy markedly increased the expression of pro-inflammatory markers, including TNF-α, IL-1β, c-Fos, BDNF, Nfl, and GFP, signifying a robust inflammatory and damage response. The injection of CVC following ISO exposure markedly decreased the expression of these markers, suggesting that CVC may exert a neuroprotective effect by regulating the inflammatory response and mitigating neuronal and glial damage. CVC demonstrated a notable protective effect on mitochondrial integrity, evidenced by the decreased mRNA expression of mitochondrial damage markers, including NSE, s100B, CALP1, and CALM1 in the CVC-treated groups, showing that CVC mitigates mitochondrial dysfunction. The analysis revealed no significant alterations in the expression levels of Aβ40, pTau181, and tTau across all groups, indicating that these biomarkers were not substantially influenced by CVC treatment under the study's conditions. However, β-amyloid accumulation varied significantly between groups, highlighting the need for further research to explore CVC's potential implications in amyloid-related diseases. These findings endorse CVC's neuroprotective efficacy and therapeutic potential in neurological disorders associated with oxidative stress, inflammation, and mitochondrial impairment.

Unlocking the Potential of Origanum Grosii Essential Oils: A Deep Dive into Volatile Compounds, Antioxidant, Antibacterial, and Anti-Enzymatic Properties within Silico Insights

The present study aimed to comprehensively characterize the volatile compounds from the aerial parts of Origanum grosii and evaluate their potential as antioxidants and enzyme inhibitors through both in vitro and in silico approaches. The essential oil's volatile constituents were identified using Gas Chromatography-Mass Spectrometry (GC-MS) analysis, revealing carvacrol (31 %), p-cymene (18.59 %), thymol (12.31 %), and ɣ-terpinene (10.89 %) as the major compounds. The antioxidant capacity was measured using three distinct assays. Notably, Origanum grosii essential oil (OGEO) exhibited significant antioxidant activity, with IC50 values of 55.40±2.23, 81.65±3.26, and 98.04±3.87 μg/mL in DPPH, ABTS, and FRAP assays, respectively. The antibacterial activity was evaluated against both Gram-positive and Gram-negative bacterial strains, including Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa IH, and Listeria monocytogenes ATCC 13932. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the broth microdilution method. The inhibitory effects of OGEO were also assessed against enzymes implicated in human pathologies, including α-glucosidase, α-amylase, tyrosinase, and acetylcholinesterase (AChE). OGEO demonstrated notable inhibitory activity with IC50 values of 49.72±1.64, 60.28±2.13, 97.14±5.15, and 119.42±2.97 μg/mL against elastase, α-glucosidase, tyrosinase, and α-amylase, respectively. Additionally, OGEO exhibited anti-AChE and anti-BChE effects, with values of 7.49±0.83 and 1.91±0.77 mg GALAE/g, respectively. The MIC values were 0.125 μg/mL for E. coli, P. aeruginosa, and S. aureus, and 0.25 μg/mL for L. monocytogenes, while MBC values ranged from 0.25 to 0.5 μg/mL. Compared to chloramphenicol (MIC: 8-16 μg/mL, MBC: 32-64 μg/mL), OGEO showed significantly stronger antibacterial effects. In silico analysis further supported the strong binding affinities of the major compounds to the target enzymes. Overall, OGEO shows promise as a natural agent with potential applications in the food, pharmaceutical, and cosmetic industries.

Plant Secondary Metabolites as Modulators of Mitochondrial Health: An Overview of Their Anti-Oxidant, Anti-Apoptotic, and Mitophagic Mechanisms

Plant secondary metabolites (PSMs) are a diverse group of bioactive compounds, including flavonoids, polyphenols, saponins, and terpenoids, which have been recognised for their critical role in modulating cellular functions. This review provides a comprehensive analysis of the effects of PSMs on mitochondrial health, with particular emphasis on their therapeutic potential. Emerging evidence shows that these metabolites improve mitochondrial function by reducing oxidative stress, promoting mitochondrial biogenesis, and regulating key processes such as apoptosis and mitophagy. Mitochondrial dysfunction, a hallmark of many pathologies, including neurodegenerative disorders, cardiovascular diseases, and metabolic syndrome, has been shown to benefit from the protective effects of PSMs. Recent studies show that PSMs can improve mitochondrial dynamics, stabilise mitochondrial membranes, and enhance bioenergetics, offering significant promise for the prevention and treatment of mitochondrial-related diseases. The molecular mechanisms underlying these effects, including modulation of key signalling pathways and direct interactions with mitochondrial proteins, are discussed. The integration of PSMs into therapeutic strategies is highlighted as a promising avenue for improving treatment efficacy while minimising the side effects commonly associated with synthetic drugs. This review also highlights the need for future research to elucidate the specific roles of individual PSMs and their synergistic interactions within complex plant matrices, which may further optimise their therapeutic utility. Overall, this work provides valuable insights into the complex role of PSMs in mitochondrial health and their potential as natural therapeutic agents targeting mitochondrial dysfunction.

Carvacrol Essential Oil as a Neuroprotective Agent: A Review of the Study Designs and Recent Advances

Neurodegenerative diseases were mostly perceived as diseases of ageing populations, but now-a-days, these diseases pose a threat to populations of all age groups despite significant improvements in quality of life. Almost all essential oils (EOs) have been reported to have some neuroprotective abilities and have been used as supplements for good mental health over the centuries. This review highlights the therapeutic potential of one such monoterpene phenolic EO, carvacrol (CV), that has the potential to be used as a main therapeutic intervention for neurodegenerative disorders. Three libraries, Google Scholar, PubMed, and ScienceDirect, were explored for research studies related to the neuroprotective roles of CV. All the research articles from these libraries were sorted out, with the first article tracing back to 2009, and the latest article was published in 2024. The positive effects of CV in the treatment of Alzheimer's and Parkinson's Diseases, multiple sclerosis, ischemia, and behavioural disorders have been supported with evidence. This review not only focused on study designs and the pharmacological pathways taken by CV for neuroprotection but also focused on demographics, illustrating the trend of CV research studies in certain countries and the preferences for the use of in vitro or in vivo models in studies. Our review provides useful evidence about the neuroprotective potential of CV; however, a lack of studies was observed regarding CV encapsulation in proper dosage forms, in particular nanoparticles, which could be further explored for CV delivery to the central nervous system.

Carvacrol improved learning and memory and attenuated the brain tissue oxidative damage in aged male rats

Introduction: Aging is an unavoidable process in the body that is accompanied by impaired tissue homeostasis and various changes. Carvacrol has attracted considerable attention for its wide range of pharmacological activities. Therefore, this study attempted to explore the protective effect of carvacrol in aged rats.Materiel and methods: The aged rats were given carvacrol (15 or 30 mg/kg/day) for 4 weeks. Morris water maze and passive avoidance tests were used to determine the learning and memory abilities of the rats. The hippocampus and cortex samples were taken for biochemical analysis.Results: In comparison to young control rats, aged control rats showed learning and memory deficits. There was improvement in the Morris water navigation test and passive avoidance test performance in the treatment groups versus the aged control group. An increment in malondialdehyde (MDA) and a decrease in total thiol groups in the hippocampus and cortex samples of aged control rats in comparison to the young control group were observed. Carvacrol decreased MDA levels and increased total thiol groups in the hippocampus and cortex samples of aged rats.Conclusion: Carvacrol improved learning and memory in aged rats, probably through its anti-oxidation effects.

The ameliorative effect of carvacrol on sodium arsenite-induced hepatotoxicity in rats: Possible role of Nrf2/HO-1, RAGE/NLRP3, Bax/Bcl-2/Caspase-3, and Beclin-1 pathways

Arsenic is a toxic environmental pollutant heavy metal, and one of its critical target tissues in the body is the liver. Carvacrol is a natural phytocompound that stands out with its antioxidant, anti-inflammatory, and antiapoptotic properties. The current study aims to investigate the protective feature of carvacrol against sodium arsenite-induced liver toxicity. Thirty-five Sprague-Dawley male rats were divided into five groups: Control, Sodium arsenite (SA), CRV, SA + CRV25, and SA + CRV50. Sodium arsenite was administered via oral gavage at a dose of 10 mg/kg for 14 days, and 30 min later, CRV 25 or 50 mg/kg was administered via oral gavage. Oxidative stress, inflammation, apoptosis, autophagy damage pathways parameters, and liver tissue integrity were analyzed using biochemical, molecular, western blot, histological, and immunohistological methods. Carvacrol decreased sodium arsenite-induced oxidative stress by suppressing malondialdehyde levels and increasing superoxide dismutase, catalase, glutathione peroxidase activities, and glutathione levels. Carvacrol reduced inflammation damage by reducing sodium arsenite-induced increased levels of NF-κB and the cytokines (TNF-α, IL-1β, IL-6, RAGE, and NLRP3) it stimulates. Carvacrol also reduced sodium arsenite-induced autophagic (Beclin-1, LC3A, and LC3B) and apoptotic (P53, Apaf-1, Casp-3, Casp-6, Casp-9, and Bax) parameters. Carvacrol preserved sodium arsenite-induced impaired liver tissue structure. Carvacrol alleviated toxic damage by reducing sodium arsenite-induced increases in oxidative stress, inflammation, apoptosis, and autophagic damage parameters in rat liver tissues. Carvacrol was also beneficial in preserving liver tissue integrity.

Individual and combined effects of cadmium and lead exposure in rats

The exposure of humans and animals to environmental compounds is rarely restricted to a single chemical. Cadmium (Cd) and lead (Pb) are two heavy metals known to be the most toxic. Deleterious effects of each metal alone are well documented. Unfortunately, very few studies were conducted to determine their combined effect. Four groups of Wistar rats were treated intravenously for 15 days. The control group received physiological saline solution; groups 2 and 3 were treated with Cd chloride and lead acetate, respectively ; and the treatment group 4 received a combined treatment of Cd and Pb . A significant decrease was recorded for hematological parameters , with an increase in white blood cells and an inhibition in δ-ALAD level. Cell injury in the livers and kidneys was clearly shown by the significant elevation of the biochemical markers. Cd and Pb induced oxidative stress and had adverse health effects at lower exposure levels than previously thought.

The effects of carvacrol and p-cymene on Aβ1-42 -induced long-term potentiation deficit in male rats

AIMS

Alzheimer's disease (AD) is the most common type of dementia in which oxidative stress plays an important role. In this disease, learning and memory and the cellular mechanism associated with it, long-term potentiation (LTP), are impaired. Considering the beneficial effects of carvacrol (CAR) and p-cymene against AD, their effect was assessed on in vivo hippocampal LTP in the perforant pathway (PP)-dentate gyrus (DG) pathway in an Aβ1-42 -induced rat model of AD.

METHODS

Male Wistar rats were randomly assigned to five groups: sham: intracerebroventricular (ICV) injection of phosphate-buffered saline, Aβ: ICV Aβ1-42 injections, Aβ + CAR (50 mg/kg), Aβ + p-cymene (50 mg/kg), and Aβ + CAR + p-cymene. Administration of CAR and p-cymene was done by gavage daily 4 weeks before and 4 weeks after the Aβ injection. The population spike (PS) amplitude and field excitatory postsynaptic potentials (fEPSP) slope were determined in DG against the applied stimulation to the PP.

RESULTS

Aβ-treated rats exhibited impaired LTP induction in the PP-DG synapses, resulting in significant reduction in both fEPSP slope and PS amplitude compared to the sham animals. Aβ-treated rats consumed either CAR or p-cymene separately (but not their combination), and showed an enhancement in fEPSP slope and PS amplitude of the DG granular cells.

CONCLUSIONS

These data indicate that CAR or p-cymene can ameliorate Aβ-associated changes in synaptic plasticity. Surprisingly, the combination of CAR and p-cymene did not yield the same effect, suggesting a potential interaction between the two substances.

Metabolomic modelling and neuroprotective effects of carvacrol against acrylamide toxicity in rat's brain and sciatic nerve

The study aimed to investigate the harmful effects of acrylamide (AA), which forms in carbohydrate-rich foods at temperatures above 120°C, on the central and peripheral nervous systems and to evaluate the potential neuroprotective effects of carvacrol (CRV). Male Wistar Albino rats were subjected to AA (40 mg/kg/bw/day) and CRV (50 mg/kg/bw/day) for 15 days. Following the last administration, evaluations revealed disrupted gait, heightened thermal sensitivity and altered paw withdrawal thresholds in AA-exposed rats. Notably, AA reduced glutathione (GSH) and raised malondialdehyde (MDA) levels in both brain and sciatic nerve tissues. AA raised nuclear factor erythroid 2-related factor 2 (Nrf2), caspase 3 and nuclear factor κB (NF-κB) gene expressions while decreasing NR4A2. CRV co-administration mitigated gait abnormalities, elevated GSH levels and lowered MDA levels in both tissues. CRV also modulated gene expression, reducing Nrf2 and NF-κB while increasing NR4A2. Histopathological signs of AA-induced neurodegeneration and elevated glial fibrillary acidic protein levels observed in brain and sciatic nerve tissues were rectified with simultaneous administration of CRV, thereby demonstrating neuroprotective efficacy in both regions. This study is pioneering in demonstrating CRV's neuroprotective potential against AA-induced neurotoxicity in both central and peripheral nervous systems, effectively addressing limitations in the literature. In conclusion, the study revealed AA-induced neurodegeneration in the brain and sciatic nerve, with CRV significantly mitigating this neurotoxicity. This novel research underscores CRV's promise as a neuroprotective agent against AA-induced adverse effects in both the central and peripheral nervous systems.

Carvacrol decreases blood-brain barrier permeability post-diffuse traumatic brain injury in rats

Previously, we showed that Satureja Khuzestanica Jamzad essential oil (SKEO) and its major component, carvacrol (CAR), 5-isopropyl-2-methylphenol, has anti-inflammatory, anti-apoptotic, and anti-edematous properties after experimental traumatic brain injury (TBI) in rats. CAR, predominantly found in Lamiaceae family (Satureja and Oregano), is lipophilic, allowing diffusion across the blood-brain barrier (BBB). These experiments test the hypothesis that acute treatment with CAR after TBI can attenuate oxidative stress and BBB permeability associated with CAR's anti-edematous traits. Rats were divided into six groups and injured using Marmarou weight drop: Sham, TBI, TBI + Vehicle, TBI + CAR (100 and 200 mg/kg) and CAR200-naive treated rats. Intraperitoneal injection of vehicle or CAR was administered thirty minutes after TBI induction. 24 h post-injury, brain edema, BBB permeability, BBB-related protein levels, and oxidative capacity were measured. Data showed CAR 200 mg/kg treatment decreased brain edema and prevented BBB permeability. CAR200 decreased malondialdehyde (MDA) and reactive oxygen species (ROS) and increased superoxide dismutase (SOD) and total antioxidative capacity (T-AOC), indicating the mechanism of BBB protection is, in part, through antioxidant activity. Also, CAR 200 mg/kg treatment suppressed matrix metalloproteinase-9 (MMP-9) expression and increased ZO-1, occludin, and claudin-5 levels. These data indicate that CAR can promote antioxidant activity and decrease post-injury BBB permeability, further supporting CAR as a potential early therapeutic intervention that is inexpensive and more readily available worldwide. However, more experiments are required to determine CAR's long-term impact on TBI pathophysiology.

Plant essential oils improve growth performance by increasing antioxidative capacity, enhancing intestinal barrier function, and modulating gut microbiota in Muscovy ducks

Essential oils (EO) are known for their antioxidant, anti-inflammatory, antimicrobial, and growth-promoting properties. However, data rgarding their impact on the intestinal health and gut microbiota of ducks remain limited. Thus, this study aimed to investigate the effects of plant EO on the growth performance, intestinal health, and gut microbiota of Muscovy ducks. A total of 360 healthy male Muscovy ducks aged 1 d were randomly divided into 4 groups with 6 replicates and 15 ducks per replicate. Ducks were fed basal diets supplemented with 0, 100, 200, or 300 mg/kg EO. The results showed that 200 mg/kg EO supplementation significantly (P < 0.05) increased the final body weight and average daily gain, while significantly (P < 0.05) decreased the feed conversion ratio during the 56-d experimental period. Furthermore, dietary 200 mg/kg EO significantly (P < 0.05) enhanced antioxidant capacity and immune function and improved the barrier function of the intestine. Additionally, 16S rDNA sequencing analysis results showed that 200 mg/kg EO favorably modulated the cecal microbial diversities and composition evidenced by the increased (P < 0.05) the abundances of short-chain fatty acid-producing bacteria (e.g., Subdoligranulum and Shuttleworthia) and decreased (P < 0.05) abundances of potential enteric pathogenic bacteria (e.g., Alistipes, Eisenbergiella, and Olsenella). The relative abundance of beneficial bacteria was positively correlated with antioxidant, immune, and barrier function biomarkers. Overall, these findings revealed that dietary supplementation with 200 mg/kg EO had several potentially beneficial effects on the growth performance of Muscovy ducks by improving antioxidant capacity, enhancing the intestinal barrier function and favorably modulating gut microbiota.

Antidepressant-like effect of endogenous SO2 on depression caused by chronic unpredictable mild stress

Sulfur dioxide (SO₂) is a toxic gas with harmful effects on various organs. However, recent studies have confirmed the protective effect of SO₂ on ischemic heart disease, atherosclerosis, and lung infections. Therefore, the present study was designed to investigate the effect of endogenous SO₂ on depression. The chronic unpredictable mild stress (CUMS) model was performed to cause depression. Depression-like behaviors in animals were determined using an open-field test, forced swimming test, and sucrose consumption. Animal spatial learning and memory were also assessed using the Morris water maze. Besides, the oxidative status of the hippocampus and serum corticosterone level were evaluated. A reduction in the tendency to consume sucrose, mobility, and curiosity, as well as learning and memory disorders were observed in CUMS animals. Depressed animals treated with SO₂ revealed a significant improvement in behavioral and cognitive functions. SO₂ also reduced neuronal damage and lipid peroxidation of the hippocampus and serum corticosterone level in the CUMS group. Various shreds of evidence support a mutual relationship between inflammation and depression; also, growing studies show the role of oxidative stress in the pathogenesis of mood-related disorders such as depression. This study indicated that increased hippocampal malondialdehyde (MDA) and serum corticosterone levels can be due to the existence of oxidative stress and possible activation of inflammatory processes. SO₂ donors diminished MDA and corticosterone levels in depressed animals. According to the study results, SO₂ may be able to reduce tissue damage and eventually behavioral disorders caused by depression by lowering oxidative stress and inflammation.

Therapeutic effects of carvacrol on beta-amyloid-induced impairments in in vitro and in vivo models of Alzheimer's disease

Due to the complex nature of Alzheimer's disease (AD), it is important to investigate agents with multiple effects in the treatment of AD. Carvacrol possesses anti-acetylcholinesterase, anti-oxidant, and neuroprotective properties. We therefore investigated therapeutic effects of carvacrol on cell viability, oxidative stress, and cognitive impairment in Aβ1-42-induced in vitro and in vivo models of AD. SH-SY5Y cells differentiated into neurons by retinoic acid were pretreated with carvacrol or galantamine before Aβ1-42 administration. For in vivo experiments, a rat model of AD was established by bilateral intrahippocampal injection of Aβ1-42. The groups received 1% DMSO, carvacrol, or galantamine intraperitoneally twice a day (morning and afternoon) for 6 days. Cell viability was determined using MTT and LDH tests. Learning and memory functions were assessed using a passive-avoidance test. Oxidant-antioxidant parameters (MDA, H₂ O₂ , SOD, and CAT) and Tau, Aβ1-40, and Aβ1-42 peptide levels in in vitro supernatant or in vivo serum and hippocampal samples were measured using ELISA. Carvacrol increased cell viability and exhibited a protective effect against oxidative stress by preventing Aβ1-42-induced cytotoxicity, LDH release, and increments in MDA and H₂ O₂ levels in vitro. Additionally, it improved memory impairment by reversing Aβ1-42-induced changes on passive-avoidance test. Carvacrol ameliorated Aβ1-42-induced increments in MDA and H₂ O₂ levels in in vitro supernatant and in vivo hippocampal samples. However, none of the treatments changed in vitro SOD and Tau-peptide levels, or in vivo serum levels of MDA, H₂ O₂ , SOD, CAT, Tau peptide, Aβ1-40, or Aβ1-42. Our results suggest that multi-target pharmacological agent carvacrol may be promising in treatment of AD by preventing beta-amyloid-induced neurotoxicity, oxidative stress, and memory deficits.

Sesamin: Insights into its protective effects against lead-induced learning and memory deficits in rats

BACKGROUND

Lead (Pb) is one of the most hazardous pollutants that induce a wide spectrum of neurological changes such as learning and memory deficits. Sesamin, a phytonutrient of the lignan class, exhibits anti-inflammatory, anti-apoptotic, and neuroprotective properties. The present study was designed to investigate the effects of sesamin against Pb-induced learning and memory deficits, disruption of hippocampal theta and gamma rhythms, inflammatory response, inhibition of blood δ-aminolevulinic acid dehydratase (δ-ALA-D) activity, Pb accumulation, and neuronal loss in rats.

METHODS

Sesamin treatment (30 mg/kg/day; P.O.) was started simultaneously with Pb acetate exposure (500 ppm in standard drinking water) in rats, and they continued for eight consecutive weeks.

RESULTS

The results showed that chronic exposure to Pb disrupted the learning and memory functions in both passive-avoidance and water-maze tests, which was accompanied by increase in spectral theta power and theta/gamma ratio, and a decrease in spectral gamma power in the hippocampus. Additionally, Pb exposure resulted in an enhanced tumor necrosis factor-alpha (TNF-α) content, decreased interleukin-10 (IL-10) production, inhibited blood δ-ALA-D activity, increased Pb accumulation, and neuronal loss of rats. In contrast, sesamin treatment improved all the above-mentioned Pb-induced pathological changes.

CONCLUSION

This data suggests that sesamin could improve Pb-induced learning and memory deficits, possibly through amelioration of hippocampal theta and gamma rhythms, modulation of inflammatory status, restoration of the blood δ-ALA-D activity, reduction of Pb accumulation in the blood and the brain tissues, and prevention of neuronal loss.

Neuroprotective effects of carvacrol against cadmium-induced neurotoxicity in rats: role of oxidative stress, inflammation and apoptosis

Cadmium (Cd), is a heavy metal reported to be associated with oxidative stress and inflammation. In this paper, we investigated the possible protective effects of carvacrol against Cd-induced neurotoxicity in rats. Adult male Sprague Dawley rats were treated orally with Cd (25 mg/kg body weight) and with carvacrol (25 and 50 mg/kg body weight) for 7 days. Carvacrol decreased the levels of malondialdehyde (MDA), glial fibrillary acidic protein (GFAP) and monoamine oxidase (MAO), and significantly increased the levels of glutathione (GSH) and activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in brain tissue. Additionally, carvacrol alleviated the in levels of inflammation and apoptosis related proteins involving p38 mitogen-activated protein kinase (p38 MAPK), cyclooxygenase-2 (COX-2), nuclear factor kappa B (NF-κB), B-cell lymphoma-3 (Bcl-3), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), myeloperoxidase (MPO), prostaglandin E2 (PGE2), neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), cysteine aspartate specific protease-3 (caspase-3) and Bcl-2 associated X protein (Bax) in the Cd-induced neurotoxicity. Carvacrol also decreased the mRNA expression of matrix metalloproteinases (MMP9 and MMP13), as well as 8-hydroxy-2'-deoxyguanosine (8 - OHdG) level, a marker of oxidative DNA damage. Collectively, our findings indicated that carvacrol has a beneficial effect in ameliorating the Cd-induced neurotoxicity in the brain of rats.

Gingko biloba abrogate lead-induced neurodegeneration in mice hippocampus: involvement of NF-κB expression, myeloperoxidase activity and pro-inflammatory mediators

Neuroimmune alterations have important implication in the neuropsychiatric symptoms and biochemical changes associated with lead-induced neurotoxicity. It has been suggested that inhibition of neuroinflammatory-mediated lead-induced neurotoxicity by phytochemicals enriched with antioxidant activities would attenuate the deleterious effects caused by lead. Hence, this study investigated the neuroinflammatory mechanism behind the effect of Ginkgo biloba supplement (GB-S) in lead-induced neurotoxicity in mice brains. Mice were intraperitoneally pretreated with lead acetate (100 mg/kg) for 30 min prior the administration of GB-S (10 and 20 mg/kg, i.p.) and ethylenediaminetetraacetic acid (EDTA) (50 mg/kg, i.p.) for 14 consecutive days. Symptoms of neurobehavioral impairment were evaluated using open field test (OFT), elevated plus maze (EPM), and tail suspension test (TST) respectively. Thereafter, mice brain hippocampi were sectioned for myeloperoxidase activity (MPO), pro-inflammatory cytokine (TNF-α and IL-6) estimation and inflammatory protein (NF-κB) expression. Furthermore, histomorphormetric studies (Golgi impregnation and Cresyl violet stainings) were carried out. GB-S (10 and 20 mg/kg) significantly restores neurobehavioral impairments based on improved locomotion, reduced anxiety- and depressive-like behavior. Moreover, GB-S reduced the MPO activity, inhibits TNF-α, IL-6 release, and downregulates NF-κB immunopositive cell expression in mice hippocampus. Histomorphometrically, GB-S also prevents the loss of pyramidal neuron in the hippocampus. The endpoint of this findings suggest that GB-S decreases neuropsychiatric symptoms induced by lead acetate through mechanisms related to inhibition of release of pro-inflammatory mediators and suppression of hippocampal pyramidal neuron degeneration in mice.

Ameliorative role of Syzygium aromaticum aqueous extract on synaptosomal tyrosine hydroxylase activity, oxidative stress parameters, and behavioral changes in lead-induced neurotoxicity in mice

This study reports the protective role of the aqueous extract of Syzygium aromaticum (ESA) against lead (Pb)-induced neurotoxicity in mice. Thirty male mice weighing between 18 g and 25 g were randomly divided into five groups. (1) Group 1 (control group), (2) group 2 (Pb-test group): was administered with a solution containing 0.1% (w/v) of lead acetate (PbAc), (3) group 3 (ESA + Pb100 group): was administered with 0.1% (w/v) of PbAc followed by 100 mg/kg of S. aromaticum extract by gavage, (4) group 4 (ESA + Pb200): was administered with 0.1% (w/v) of PbAc followed by 200 mg/kg of S. aromaticum extract, and (5) group 5 (ESA-group): was administered with 100 mg/kg of S. aromaticum. Level of lead was determined by atomic absorption spectroscopy. Cerebral cortex synaptosomes prepared from mice administered orally with lead-acetate shown a significantly increased (p < .05) in tyrosine hydroxylase and protein carbonyl level and significantly decreased (p < .05) superoxide dismutase, glutathione reductase, and glutathione transferase activities. Also, there was a significant increase in brain lead concentration level, however, it was observed that S. aromaticum significantly reduced (p < .05) the level of lead at all tested doses. S. aromaticum rescued cerebral cortex synaptosomes from lead-induced neurotoxicity by relieving oxidative stress and abating elevated tyrosine hydroxylase activity. Moreover, S. aromaticum at the different dose grade (100 mg and 200 mg) abrogated the loss of motor performance in mice groups induced with lead. Altogether, our findings showed that S. aromaticum possesses antioxidant and neuro-modulatory potential against lead-induced neuronal damage. PRACTICAL APPLICATIONS: Environmental pollution with heavy metals is a known public health concern and their incremental concentrations in soil and water have risen to an unprecedented degree. Lead is one of the top 10 contaminants on the WHO's list of substances of greatest public health concern that impact the brain. However, exogenous natural bioactive supplements molecules could be one of the remedies to reduce Pb-induced toxicity. Our findings indicate therefore that, S. aromaticum could be a good fit for lowering Pb neurotoxicity and could be suggested as a neuroprotective molecule against neurodegenerative diseases involving catecholaminergic dysfunction induced by metallic elements.

Ethnomedicinal use, phytochemistry, pharmacology, and toxicology of Daphne gnidium: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Daphne gnidium L., (Lazaz or Metnan) is a perennial plant that grows around the Mediterranean basin, in Southern Europe, North Africa and the Middle East. It is used in different countries for hair care and to treat several diseases including skin cancer, diabetes, nervous breakdowns, sinusitis, poisoning, rheumatic disorders, odontalgia, muscular pain, and gastrointestinal infections. It is also used as anti-inflammatory, insecticide, and anti-parasitic remedy.

AIM OF THE REVIEW

In this review, previous studies on D. gnidium including its botanical description, taxonomy, geographical distribution, medicinal use, phytochemistry, and pharmacological properties were critically highlighted and discussed for suggesting the exploration of this specie and its bioactive compounds in medical applications.

MATERIALS AND METHODS

Data on D. gnidium were gathered from Scientific search engines including PubMed, ScienceDirect, SpringerLink, Web of Science, Scopus, Wiley Online, SciFinder, and Google Scholar. Reports on D. gnidium written in English published before September 2020 were summarized.

RESULTS

In traditional medicine, D. gnidium is used to treat diabetes, gastrointestinal infections, skin cancer, nervous breakdowns, and sinusitis. The extracts and essential oil of D. gnidium exhibited several biological properties such as antibacterial, antifungal, antiviral, antigenotoxic, hemolytic, anti-inflammatory, immunomodulatory, neuroprotective, allelopathic, and insecticidal effects. Phytochemical investigations identified several chemical classes of secondary metabolites in D. gnidium essential oil and extracts including terpenoids, coumarins, flavonoids, fatty acids, and alkanes.

CONCLUSIONS

The findings presented in this study showed a link between the traditional medicinal use and scientific biological results about D. gnidium. However, further investigations should be carried out to support medical and cosmetic applications of this species. Indeed, D. gnidium and its main compounds should be confirmed concerning their safety and their bioavailability. Moreover, pharmacodynamic studies should be conducted to support their efficacy in medical applications.

Activity of Selected Group of Monoterpenes in Alzheimer's Disease Symptoms in Experimental Model Studies-A Non-Systematic Review

Alzheimer's disease (AD) is the leading cause of dementia and cognitive function impairment. The multi-faced character of AD requires new drug solutions based on substances that incorporate a wide range of activities. Antioxidants, AChE/BChE inhibitors, BACE1, or anti-amyloid platelet aggregation substances are most desirable because they improve cognition with minimal side effects. Plant secondary metabolites, used in traditional medicine and pharmacy, are promising. Among these are the monoterpenes-low-molecular compounds with anti-inflammatory, antioxidant, enzyme inhibitory, analgesic, sedative, as well as other biological properties. The presented review focuses on the pathophysiology of AD and a selected group of anti-neurodegenerative monoterpenes and monoterpenoids for which possible mechanisms of action have been explained. The main body of the article focuses on monoterpenes that have shown improved memory and learning, anxiolytic and sleep-regulating effects as determined by in vitro and in silico tests-followed by validation in in vivo models.