Amelioration of amyloid β-induced cognitive deficits by Zataria multiflora Boiss. essential oil in a rat model of Alzheimer's disease

The effect of inhaled aromatherapy on cognitive function in patients with cognitive impairment: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Cognitive function is the basis of human thinking and behavior. Cognitive impairment has a serious impact on each individual and imposes a financial burden to families and healthcare systems. Inhalation aromatherapy has advantages, due to its safety, convenience, lack of toxicity, and wide use in the treatment of cognitive impairment. This systematic review was conducted to provide evidence for the use of inhaled aromatherapy in patients with cognitive impairment.

METHODS

We searched nine databases for pertinent Chinese and English studies published through November 2024 studies using inhaled aromatherapy in patients with cognitive impairment. Literature screening and data extraction were performed independently by two researchers and evaluated using the Cochrane Collaboration's quality criteria and were then cross-checked. A meta-analysis was carried out using Cochrane's Review Manager (RevMan, version 5.4), and we followed the PRISMA guidelines.

RESULTS

We included fourteen studies involving 888 patients with cognitive impairment in our study. Meta-analyses indicated that inhaled aromatherapy increased Mini-mental State Examination (MMSE, mean difference MD = 3.89 95 % CI [3.19, 4.58], P < 0.00001) and Montreal Cognitive Assessment Scale (MoCA, MD = 4.11, 95 % CI [3.54, 4.68], P < 0.00001) scores and decreased Homocysteine levels (Hcy, MD = -2.27 95 % CI [-2.80, -1.74], P < 0.00001) in patients with cognitive impairment compared with controls.

CONCLUSION

Inhaled aromatherapy could improve global cognition and lower Hcy in patients with cognitive impairment.

Effects of Lamiaceae family plants and their bioactive ingredients on coronavirus-induced lung inflammation

Coronaviruses (CoVs) are a family of viruses that cause infection in respiratory and intestinal systems. Different types of CoVs, those responsible for the SARS-CoV and the new global pandemic of coronavirus disease 2019 in people, have been found. Some plants were used as food additives: spices and dietary and/or medicinal purposes in folk medicine. We aimed to provide evidence about possible effects of two Lamiaceae family plants on control or treatment of CoVs-induced inflammation. The keywords including coronaviruses, Thymus vulgaris, Zataria multiflora, thymol, carvacrol, antivirus, and anti-inflammatory and antioxidant effects were searched in various databases such as PubMed, Web of Sciences (ISI), and Google Scholar until September 2022. The medicinal herbs and their main ingredients, thymol and carvacrol, showed antiviral properties and reduced inflammatory mediators, including IL-1β; IL-6, and TNF-α, at both gene and protein levels but increased the levels of IFN-γ in the serum as anti-inflammatory cytokine. These medicinal herbs and their constituents also reduce oxidative stress and enhance antioxidant capacity. The results of molecular docking analyses also indicated that polyphenol components such as thymol, carvone, and carvacrol could inhibit the entry of the viruses into the host cells in molecular docking analyses. The antiviral, anti-inflammatory, and antioxidant effects of these plants may be due to actions of their phenolic compounds that modulate immune response and may be useful in the control and treatment of CoV-induced lung disorder.

A Comprehensive Review of Essential Oils and Their Pharmacological Activities in Neurological Disorders: Exploring Neuroprotective Potential

Numerous studies have demonstrated essential oils' diverse chemical compositions and pharmacological properties encompassing antinociceptive, anxiolytic-like, and anticonvulsant activities, among other notable effects. The utilization of essential oils, whether inhaled, orally ingested, or applied topically, has commonly been employed as adjunctive therapy for individuals experiencing anxiety, insomnia, convulsions, pain, and cognitive impairment. The utilization of synthetic medications in the treatment of various disorders and symptoms is associated with a wide array of negative consequences. Consequently, numerous research groups across the globe have been prompted to explore the efficacy of natural alternatives such as essential oils. This review provides a comprehensive overview of the existing literature on the pharmacological properties of essential oils and their derived compounds and the underlying mechanisms responsible for these observed effects. The primary emphasis is on essential oils and their constituents, specifically targeting the nervous system and exhibiting significant potential in treating neurodegenerative disorders. The current state of research in this field is characterized by its preliminary nature, highlighting the necessity for a more comprehensive overlook of the therapeutic advantages of essential oils and their components. Integrating essential oils into conventional therapies can enhance the effectiveness of comprehensive treatment regimens for neurodegenerative diseases, offering a more holistic approach to addressing the multifaceted nature of these conditions.

Neuroprotective Effect of Zishen Huoxue Decoction treatment on Vascular Dementia by activating PINK1/Parkin mediated Mitophagy in the Hippocampal CA1 Region

ETHNOPHARMACOLOGICAL RELEVANCE

Zishen Huoxue Decoction (ZSHXD) is a Traditional Chinese Medicine (TCM) prescription for the treatment of vascular dementia (VD). Although the clinical effects of ZSHXD have been demonstrated, the molecular mechanisms underlying the neuroprotective effects of ZSHXD remain unclear.

AIM OF THE STUDY

To explore whether the neuroprotective effect of Zishen Huoxue Decoction (ZSHXD) treatment is associated with the PINK1/Parkin pathway-mediated mitophagy in hippocampal CA1 region of 2-VO model rats.

MATERIALS AND METHODS

Seventy-two male SD rats were randomly divided into the sham group, model group, Donepezil (0.45 mg/kg) group, ZSHXD low dose group (8.9 g/kg), ZSHXD medium dose group (17.8 g/kg), and ZSHXD high dose group (35.6 g/kg). Two-vessel occlusion (2-VO) rat model is established to evaluate the therapeutic effect of ZSHXD pretreatment. Hematoxylin-eosin (HE) staining is conducted to detect the morphological changes of neurons and the number of normal neurons in the hippocampal CA1 region. Then, the mitochondrial function and structure were reflected by the mitochondrial membrane potential (MMP) levels and transmission electron microscopy (TEM). Meanwhile, the expression of mitophagy related proteins mediated by PINK1/Parkin was detected by western blot (WB). After that, malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured by Elisa. At last, the apoptosis-related proteins Caspase-3、Bax、Bcl-2 were measured by WB.

RESULTS

The results depict that ZSHXD has dose-dependently improved the cognitive function in 2-VO model rats. It has also been showed that ZSHXD can alleviate neuron damage, rescue the mitochondrial structural injury and dysfunction in hippocampal CA1 region. Besides, ZSHXD has increased the activity of SOD and decreased the activity of MDA. In addition, ZSHXD can inhibit apoptosis with Caspase-3, Bax decreasing and Bcl-2 increasing. Specially, the protection of ZSHXD showed in 2-VO model rats is along with the upregulation of PINK1, Parkin and LC3-Ⅱ/Ⅰ, and downregulation of p62 in the hippocampal CA1 region.

CONCLUSIONS

This study reveals that ZSHXD protects the 2-VO model rats from ischemic injury by activating the PINK1/Parkin-mediated mitophagy in the hippocampal CA1 region.

Assessment of the Anti-Amyloidogenic Properties of Essential Oils and Their Constituents in Cells Using a Whole-Cell Recombinant Biosensor

Essential oils exhibit numerous medicinal properties, including antimicrobial, anti-inflammatory and antioxidant effects. Recent studies also indicate that certain essential oils demonstrate anti-amyloidogenic activity against β-amyloid, the protein implicated in Alzheimer's disease. To investigate whether the anti-aggregating properties of essential oils extend to α-synuclein, the protein involved in Parkinson's disease, we constructed and employed a whole-cell biosensor based on the split-luciferase complementation assay. We validated our biosensor by using baicalein, a known inhibitor of α-synuclein aggregation, and subsequently we tested eight essential oils commonly used in food and the hygienic industry. Two of them, citron and sage, along with their primary components, pure linalool (the main constituent in citron essential oil) and pure eucalyptol (1,8-cineole, the main constituent in sage essential oil), were able to reduce α-syn aggregation. These findings suggest that both essential oils and their main constituents could be regarded as potential components in functional foods or incorporated into complementary Parkinson's disease therapies.

Therapeutic potential of aromatic plant extracts in Alzheimer's disease: Comprehensive review of their underlying mechanisms

AIMS

The aim of this review is to outline recent advancements in the application and mechanistic studies of aromatic plant extracts in Alzhermer`s disease (AD) to demonstrate their value in the management of this disease.

BACKGROUND

AD is a neurodegenerative disease with a complex pathogenesis characterized by severe cognitive impairment. Currently, there are very few drugs available for the treatment of AD, and treatments are primarily focused on symptom relief. Aromatherapy is a traditional complementary alternative therapy that focuses on the prevention and treatment of the disease through the inhalation or transdermal administration of aromatic plant extracts. Over the past few years, studies on the use of aromatic plant extracts for the treatment of AD have been increasing and have demonstrated a definitive therapeutic effect.

METHODS

We systematically summarized in vitro, in vivo, and clinical studies focusing on the potential use of aromatic plant extracts in the treatment of AD in PubMed, ScienceDirect, Google Scholar, and the Chinese National Knowledge Infrastructure from 2000 to 2022.

RESULTS

Our literature survey indicates that aromatic plant extracts exert anti-AD effects by modulating pathological changes through anti-amyloid, anti-tau phosphorylation, anti-cholinesterase, anti-inflammation, and anti-oxidative stress mechanisms (Figure 1).

CONCLUSION

This review provides a future strategy for the research of novel anti-AD drugs from aromatic plant extracts.

Natural essential oils derived from herbal medicines: A promising therapy strategy for treating cognitive impairment

Cognitive impairment (CI), mainly Alzheimer’s disease (AD), continues to increase in prevalence and is emerging as one of the major health problems in society. However, until now, there are no first-line therapeutic agents for the allopathic treatment or reversal of the disease course. Therefore, the development of therapeutic modalities or drugs that are effective, easy to use, and suitable for long-term administration is important for the treatment of CI such as AD. Essential oils (EOs) extracted from natural herbs have a wide range of pharmacological components, low toxicity, and wide sources, In this review, we list the history of using volatile oils against cognitive disorders in several countries, summarize EOs and monomeric components with cognitive improvement effects, and find that they mainly act by attenuating the neurotoxicity of amyloid beta, anti-oxidative stress, modulating the central cholinergic system, and improving microglia-mediated neuroinflammation. And combined with aromatherapy, the unique advantages and potential of natural EOs in the treatment of AD and other disorders were discussed. This review hopes to provide scientific basis and new ideas for the development and application of natural medicine EOs in the treatment of CI.

Inhalation of Cananga odorata essential oil relieves anxiety behaviors in autism-like rats via regulation of serotonin and dopamine metabolism

OBJECTIVE

Anxiety is one of the most common symptoms associated with autistic spectrum disorder. The essential oil of Cananga odorata (Lam.) Hook. f. & Thomson, usually known as ylang-ylang oil (YYO), is often used in aromatherapy as a mood-regulating agent, sedative, or hypotensive agent. In the present study, the effects and mechanisms of YYO in alleviating anxiety, social and cognitive behaviors in autism-like rats were investigated.

METHODS

The prenatal valproic acid (VPA) model was used to induce autism-like behaviors in offspring rats. The effectiveness of prenatal sodium valproate treatment (600 mg/kg) on offspring was shown by postnatal growth observation, and negative geotaxis, olfactory discrimination and Morris water maze (MWM) tests. Then three treatment groups were formed with varying exposure to atomized YYO to explore the effects of YYO on the anxiety, social and cognitive behaviors of the autistic-like offspring through the elevated plus-maze test, three-chamber social test, and MWM test. Finally, the monoamine neurotransmitters, including serotonin, dopamine and their metabolites, in the hippocampus and prefrontal cortex (PFC) of the rats were measured using a high-performance liquid chromatography.

RESULTS

Offspring of VPA exposure rats showed autism-like behaviors. In the VPA offspring, medium-dose YYO exposure significantly elevated the time and entries into the open arms in the elevated plus-maze test, while low-dose YYO exposure significantly enhanced the social interaction time with the stranger rat in session 1 of the three-chamber social test. VPA offspring treated with YYO exposure used less time to reach the platform in the navigation test of the MWM test. YYO exposure significantly elevated the metabolism of serotonin and dopamine in the PFC of VPA offspring.

CONCLUSION

YYO exposure showed the effects in alleviating anxiety and improving cognitive and social abilities in the offspring of VPA exposure rats. The role of YYO was related to the regulation of the metabolism of serotonin and dopamine. Please cite this article as: Zhang N, Wang ST, Yao L. Inhalation of Cananga odorata essential oil relieves anxiety behaviors in autism-like rats via regulation of serotonin and dopamine metabolism. J Integr Med. 2023; Epub ahead of print.

Natural Bioactive Molecules as Neuromedicines for the Treatment/Prevention of Neurodegenerative Diseases

The brain is vulnerable to different types of stresses, particularly oxidative stress as a result of oxygen requirements/utilization in the body. Large amounts of unsaturated fatty acids present in the brain increase this vulnerability. Neurodegenerative diseases (NDDs) are brain disorders that are characterized by the gradual loss of specific neurons and are attributed to broad evidence of cell-level oxidative stress. The accurate characterization of neurological disorders relies on several parameters along with genetics and environmental risk factors, making therapies less efficient to fight NDDs. On the way to tackle oxidative damage and discover efficient and safe therapies, bioactives are at the edge of NDD science. Naturally occurring bioactive compounds such as polyphenols, carotenoids, essential fatty acids, phytosterols, essential oils, etc. are particularly of interest owing to their potent antioxidant and anti-inflammatory activities, and they offer lots of brain-health-promoting features. This Review focuses on probing the neuroefficacy and bioefficacy of bioactives and their role in supporting relatively low antioxidative and low regenerative capacities of the brain, neurogenesis, neuroprotection, and ameliorating/treating NDDs.

Neuroprotective effects of carvacrol against Alzheimer's disease and other neurodegenerative diseases: A review

Objective

Neurodegenerative diseases are considered an important cause of cognitive deficit and morbidity in old ages. Alzheimer's disease (AD) is one of these disorders affecting about 40 million people in the world at the present time. Available drug therapy is mostly symptomatic and does not modify or stop disease progression. Recently, biologically active chemicals from herbs have been studied to develop new therapeutic drugs. Carvacrol has shown positive properties on many neurological diseases. This compound is expected to have the ability to affect AD pathogenesis and therefore, it is considered an anti-AD agent.

Materials and Methods

This review was conducted using PubMed, Google Scholar and Science Direct bibliographic databases until November 2021. For data collection, the following keywords were used: carvacrol, neuroprotective, cognition, anti-inflammatory, antioxidant, Acetylcolinesterase inhibitor (AChEI), Alzheimer's, Parkinson's, epilepsy, stroke, ischemic brain injury, and neurodegenerative diseases.

Results

This review summarizes in vitro and in vivo studies on protective potential of carvacrol in neurodegenerative disorders and various underlying mechanisms, such as anti-inflammatory, antioxidant, and anticholinesterase effects.

Conclusion

We gave an overview of available literature concerning neuroprotective effects of carvacrol in ameliorating the neurodegenerative diseases symptoms in vivo and in vitro. Particular attention is given to AD. Several neuro-pharmacological actions of carvacrol have been summarized in the current review article including anti-inflammatory, antioxidant, and AChEI properties.

Neuroprotective and memory enhancing effects of Zataria multiflora in lipopolysaccharide-treated rats

The study was aimed to evaluate the effects of hydro-ethanol extract Zataria multiflora on the brain tissue oxidative damage, and hippocampal interleukin-6 (IL-6) as well as learning and memory capacity in lipopolysaccharide (LPS) - challenged rats. The rats were randomized into five groups as follow: Control group: Rats were treated with saline, LPS group: Rats were treated with LPS 1.00 mg kg-1, ZM50, ZM100 and ZM200 groups in which the rats were treated with Z. multiflora extract (50.00, 100 or 200 mg kg-1 per day, respectively). The treatments including extract or vehicle were administered intraperitoneally ‎and given three days before the behavioral tests and were continued within a6-day behavioral experiment. Injection of LPS was daily done before the behavioral tests. Finally, the brains were collected for biochemical evaluations. Although LPS administration prolonged the latency in Morris water maze and shortened the latency to enter the dark chamber in passive avoidance test, ZM extract restored these changes to approach control group values. Also, LPS increased IL-6, malondialdehyde (MDA) and nitric oxide (NO) metabolites levels and lowered thiol, superoxide dismutase (SOD) and catalase (CAT) levels in the brain, however, Z. multiflora extract reduced IL-6, MDA and NO metabolites concentrations, but increased thiol content, SOD, and CAT levels. The results of this study showed that Z. multiflora ameliorated learning and memory dysfunction in LPS - challenged rats by alleviating of inflammatory responses and brain tissue oxidative damage.

Cirsium japonicum var. Maackii Improves Cognitive Impairment under Amyloid Beta25-35-Induced Alzheimer’s Disease Model

Abnormal production and degradation of amyloid beta (Aβ) in the brain lead to oxidative stress and cognitive impairment in Alzheimer’s disease (AD). Cirsium japonicum var. maackii (CJM) is widely used as an herbal medicine and has antibacterial and anti-inflammatory properties. This study focused on the protective effect of the ethyl acetate fraction from CJM (ECJM) on Aβ25-35-induced control mice. In the T-maze and novel object recognition test, ECJM provided higher spatial memory and object recognition compared to Aβ25-35 treatment alone. In the Morris water maze test, ECJM-administered mice showed greater learning and memory abilities than Aβ25-35-induced control mice. Additionally, ECJM-administered mice experienced inhibited lipid peroxidation and nitric oxide production in a dose-dependent manner. The present study indicates that ECJM improves cognitive impairment by inhibiting oxidative stress in Aβ25-35-induced mice. Therefore, CJM may be useful for the treatment of AD and may be a potential material for functional foods.

Drug Delivery of Natural Products Through Nanocarriers for Effective Breast Cancer Therapy: A Comprehensive Review of Literature

Despite recent advances in the diagnosis and treatment of breast cancer (BC), it remains a global health issue affecting millions of women annually. Poor prognosis in BC patients is often linked to drug resistance as well as the lack of effective therapeutic options for metastatic and triple-negative BC. In response to these unmet needs, extensive research efforts have been devoted to exploring the anti-BC potentials of natural products owing to their multi-target mechanisms of action and good safety profiles. Various medicinal plant extracts/essential oils and natural bioactive compounds have demonstrated anti-cancer activities in preclinical BC models. Despite the promising preclinical results, however, the clinical translation of natural products has often been hindered by their poor stability, aqueous solubility and bioavailability. There have been attempts to overcome these limitations, particularly via the use of nano-based drug delivery systems (NDDSs). This review highlights the tumour targeting mechanisms of NDDSs, the advantages and disadvantages of the major classes of NDDSs and their current clinical status in BC treatment. Besides, it also discusses the proposed anti-BC mechanisms and nanoformulations of nine medicinal plants' extracts/essential oils and nine natural bioactive compounds; selected via the screening of various scientific databases, including PubMed, Scopus and Google Scholar, based on the following keywords: "Natural Product AND Nanoparticle AND Breast Cancer". Overall, these nanoformulations exhibit improved anti-cancer efficacy against preclinical BC models, with some demonstrating biocompatibility with normal cell lines and mouse models. Further clinical studies are, however, warranted to ascertain their efficacy and biocompatibility in humans.

The effect of Zataria multiflora hydroalcoholic extract on memory and lung changes induced by rats that inhaled paraquat

Objectives: The effects of hydroalcoholic extract of Zataria multiflora (Z. multiflora) on memory changes, as well as lung injury due to inhaled paraqut (PQ) in rat, were examined.Method: Control group of rat with saline aerosol administration, PQ groups with PQ aerosol (27 and 54 mg/m3) administration, PQ groups treated with two doses of the extract (200 and 800 mg/kg/day) and dexamethasone (0.03 mg/kg/day) were studied. Shuttle box and Morris Water Maze (MWM) tests were carried out as well as oxidant, anti-oxidant markers, total and differential white blood cell (WBC) counts and cytokine levels in broncho-alveolar lavage (BALF).Results: Inhaled PQ significantly increased the escape latency and travelled distance in MWM test, but the time spent in the target quadrant on the probe day was significantly reduced (p < 0.05 to p < 0.001). The latency to enter the dark room at 3, 24, and 48 h after an electrical shock was reduced due to PQ (p < 0.05 to p < 0.001). Exposure to PQ significantly increased total WBC, neutrophil, eosinophil, lymphocyte, and monocyte counts, IL-10, interferon gama (INF-γ), nitrite (NO2), and malondialdehyde (MDA) levels, but catalase (CAT), superoxide dismutase (SOD), and thiol levels were decreased (p < 0.05 to p < 0.00). Z. multiflora and dexamethasone treatment significantly improved all behavioral as well as lung changes induced by inhaled PQ (p < 0.05 to p < 0.01).Conclusion: Z. multiflora treatment improved learning and memory impairment as well as lung inflammation and oxidative stress induced by inhaled PQ.

In-vitro (2D and 3D cultures) and in-vivo cytotoxic properties of Zataria multiflora essential oil (ZEO) emulsion in breast and cervical cancer cells along with the investigation of immunomodulatory potential

ETHNOPHARMACOLOGICAL RELEVANCE

Zataria multiflora is an iranian valuable traditional plants, called Avishan Shirazi in Persian language used to reduce inflammation, spasm, pain, and cancer symptoms. Zataria essential oil (ZEO) is one of the essential oils possessing broad biological activities.

AIM OF THE STUDY

The aim was to investigate the anticancer effects of ZEO both in-vitro and in-vivo using mouse mammary carcinoma 4T1 cell line and mouse cervical cancer TC1 cell line.

MATERIAL AND METHODS

The in-vitro effects of ZEO on the proliferation of these cell lines were considered in 2D and 3D culture by MTT assay. In the following, to indicate death mode, fluorescence staining, AnnexinV/PI flowcytometry and caspase-3 activity assay of monolayer cells treated with ZEO was done. In order to evaluate the antitumor activities of ZEO, tumor-bearing BALB/c and C57BL/6 mice were intraperitoneally administered with ZEO and the immunomodulatory effects of ZEO were considered through cytokine assay. Additionally, hematobiochemical factors including aspartate aminotransferase and alanine aminotransferase were investigated to confirm the harmless effects of ZEO.

RESULTS

The In-vitro results showed that treatment of cells with ZEO leads to significant inhibition of 4T1 and TC1 cell proliferation and apoptosis in monolayer cell culture (2D) and multicellular spheroids (3D). Based on In-vivo results, ZEO was effective in decreasing the tumor weight compared to the control. Furthermore, ZEO was effective in tilting the balance of cytokines in favor of T helper 1 through the increase in the secretion of TNF-α, IFN-γ, IL-2 and decrease in IL-4. During the treatment with ZEO, hematobiochemical factors of mice did not significantly change.

CONCLUSION

the present study demonstrated that the ZEO has potent antiproliferative, apoptosis-inducing and immune system stimulant properties in breast and cervical cancer.

Zataria multiflora affects clinical symptoms, oxidative stress and cytokines in asthmatic patient: A randomized, double blind, placebo-controlled, phase II clinical trial

BACKGROUND

Z. multiflora effect on clinical symptoms, pulmonary function tests (PFT), oxidative stress and cytokine levels in asthmatic patients were evaluated.

METHODS

36 asthmatic patients were divided to; placebo group (P), two groups treated with Z. multiflora extract (5 and 10 mg/kg/day, as Z5 and Z10, respectively), (n = 12 in each group). Medications were administered three times a day for two months and several parameters were evaluated before treatment (step 0), one (step 1) and two months (step 2) after treatment.

RESULTS

Clinical symptoms and PFTs were significantly improved in Z5 and Z10 groups in steps 1 and 2 compared to step 0 (p < 0.05 to p < 0.001). Improvement of oxidative stress, cytokines levels and their gene expression after treatment with both doses of extract were observed in step 2 compared to step 0 (p < 0.05 to p < 0.001).

CONCLUSION

These results indicated therapeutic value of Z. multiflora for the management of asthma.

Anticonvulsant Essential Oils and Their Relationship with Oxidative Stress in Epilepsy

Epilepsy is a most disabling neurological disorder affecting all age groups. Among the various mechanisms that may result in epilepsy, neuronal hyperexcitability and oxidative injury produced by an excessive formation of free radicals may play a role in the development of this pathology. Therefore, new treatment approaches are needed to address resistant conditions that do not respond fully to current antiepileptic drugs. This paper reviews studies on the anticonvulsant activities of essential oils and their chemical constituents. Data from studies published from January 2011 to December 2018 was selected from the PubMed database for examination. The bioactivity of 19 essential oils and 16 constituents is described. Apiaceae and Lamiaceae were the most promising botanical families due to the largest number of reports about plant species from these families that produce anticonvulsant essential oils. Among the evaluated compounds, β-caryophyllene, borneol, eugenol and nerolidol were the constituents that presented antioxidant properties related to anticonvulsant action. These data show the potential of these natural products as health promoting agents and use against various types of seizure disorders. Their properties on oxidative stress may contribute to the control of this neurological condition. However, further studies on the toxicological profile and mechanism of action of essential oils are needed.

Natural Monoterpenes: Much More than Only a Scent

Terpenes are a widespread group of secondary metabolites that can be found in various family plants such as the Lamiaceae. In view of their numerous valuable biological activities, the industrial production of concrete terpenes and essential oils rich in the substances is intensively studied. Monoterpenes constitute a significant part of the whole group of the aforementioned secondary metabolites. This is due to their numerous biological activities and their ability to permeate the skin. Despite the fact that these substances have gain popularity, they are not comprehensively characterized. The presented review is based on studies of the biological activities of the most important monoterpenes and the essential oils rich in these compounds. The authors focused attention on antioxidant activity, inhibition towards acetyl- and butyrylcholinesterase, and α-amylase and α-glucosidase, antifungal, hepatoprotective, sedative properties, and their skin permeation enhancement.

Zataria multiflora could improve hippocampal tau protein and TNFα levels and cognitive behavior defects in a rat model of Alzheimer's disease

OBJECTIVE

Zataria multiflora (ZM) is a plant with ethnopharmacological value which was recently tested to reduce symptoms of Alzheimer's disease (AD). The aim of the present study was to determine the effect of ZM essential oil on spatial cognitive and noncognitive behavior, as well as hippocampal tau protein and tumor necrosis factor alpha (TNFα) concentrations in rats with AD.

MATERIALS AND METHODS

Thirty-five adult male Sprague Dawley rats (300±30 g) were randomly divided into 5 groups: control (intact rats); sham (received intracerebroventricular (ICV) microinjection of normal saline); AD control (rats with AD that did not receive any treatment); vehicle control (rats with AD that orally received tween-80, 5% (ZM essential oil vehicle) for 20 days) and experimental (rats with AD that orally received ZM essential oil 100 µl/kg/day for 20 days). AD was induced by bidirectional microinjection of β amyloid 1-42 (10 µg/2µl). Tau protein and TNFα concentrations were measured by ELISA methods. Spatial cognitive and noncognitive behavior were determined by Morris water maze (MWM) test.

RESULTS

ZM essential oil significantly improved latency time, time spent in the target quarter and cognitive behavior of rats with AD compared to control and sham groups (p<0.05). Hippocampal tau protein and TNFα concentrations were significantly higher in both AD control and vehicle groups compared to control and sham groups respectively (p<0.01 and p<0.001), administration of ZM essential oil reduced these parameters as compared to AD control and vehicle groups respectively (p<0.01 and p<0.001).

CONCLUSION

ZM essential oil improves spatial learning and memory of rats with AD as assessed by MWM test. These effects are associated with decreased concentrations of hippocampal tau protein and TNFα.

Amelioration of Prenatal Lead-Induced Learning and Memory Impairments by Methanolic Extract of Zataria Multiflora in Male Rats

Introduction

The current study aimed at evaluating the effects of Zataria Multiflora (ZM) on learning and memory of adult male offspring rats with prenatal lead-exposure.

Methods

Pregnant rats in the case group received tap water containing 0.2% lead acetate throughout the gestation period. Control rats had free access to lead-free tap water. Two male offspring (two-month-old, weighing 180-200 g) from each mother were randomly selected and treated with either Z. Multiflora (50, 200, 400, and 800 mg/kg/Intraperitoneally (I.P)/20 day) or saline. Spatial memory of the control, saline, and ZM-treated rats was evaluated by a training trial and probe test using Morris water maze (6-8 rat/group).

Results

The obtained results showed memory deficits including increased escape latency, and a greater traveled distance, as well as decrements in the frequency of crossings into target quadrants in prenatally lead-exposed male offspring compared with the controls. ZM treatment (200 mg/kg/i.p) ameliorated the memory deficits in male offspring by increasing the time spent and traveled distance in the trigger zone (P<0.01 vs. saline).There was no significant difference in swimming speed between the groups.

Conclusion

The results showed memory deficits in prenatally lead-exposed male offspring. ZM treatment (especially 200 mg/kg) had beneficial effects on cognitive behavior and was indicated as the improvement of lead-induced memory deficits in prenatally lead-exposed male rats. The exact mechanism(s) is not determined yet, but it could be mediated through the anticholinesterase and antioxidant effects and also alterations in Central Nervous System (CNS) and neurotransmission in the central nervous system.

Neuroprotective potency of some spice herbs, a literature review

In recent years, growing attention has been given to traditional medicine. In traditional medicine a large number of plants have been used to cure neurodegenerative diseases such as Alzheimer's disease (AD) and other memory related disorders. Crocus sativus (C. sativus), Nigella sativa (N. sativa), Coriandrum sativum (C. sativum), Ferula assafoetida (F. assafoetida), Thymus vulgaris (T. vulgaris), Zataria multiflora (Z. multiflora) and Curcuma longa (C. longa) were used traditionally for dietary, food additive, spice and various medicinal purposes. The Major components of these herbs are carotenoids, monoterpenes and poly phenol compounds which enhanced the neural functions. These medicinal plants increased anti-oxidant, decreased oxidant levels and inhibited acetylcholinesterase activity in the neural system. Furthermore, neuroprotective of plants occur via reduced pro-inflammatory cytokines such as IL-6, IL-1β, TNF-α and total nitrite generation. Therefore, the effects of the above mentioned medicinal and their active constituents improved neurodegenerative diseases which indicate their therapeutic potential in disorders associated with neuro-inflammation and neurotransmitter deficiency such as AD and depression.

Amelioration of Prenatal Lead-Induced Learning and Memory Impairments by Methanolic Extract of Zataria Multiflora in Male Rats

Introduction:

The current study aimed at evaluating the effects of Zataria Multiflora (ZM) on learning and memory of adult male offspring rats with prenatal lead-exposure.

Methods:

Pregnant rats in the case group received tap water containing 0.2% lead acetate throughout the gestation period. Control rats had free access to lead-free tap water. Two male offspring (two-month-old, weighing 180–200 g) from each mother were randomly selected and treated with either Z. Multiflora (50, 200, 400, and 800 mg/kg/Intraperitoneally (I.P)/20 day) or saline. Spatial memory of the control, saline, and ZM-treated rats was evaluated by a training trial and probe test using Morris water maze (6–8 rat/group).

Results:

The obtained results showed memory deficits including increased escape latency, and a greater traveled distance, as well as decrements in the frequency of crossings into target quadrants in prenatally lead-exposed male offspring compared with the controls. ZM treatment (200 mg/kg/i.p) ameliorated the memory deficits in male offspring by increasing the time spent and traveled distance in the trigger zone (P<0.01 vs. saline).There was no significant difference in swimming speed between the groups.

Conclusion:

The results showed memory deficits in prenatally lead-exposed male offspring. ZM treatment (especially 200 mg/kg) had beneficial effects on cognitive behavior and was indicated as the improvement of lead-induced memory deficits in prenatally lead-exposed male rats. The exact mechanism(s) is not determined yet, but it could be mediated through the anticholinesterase and antioxidant effects and also alterations in Central Nervous System (CNS) and neurotransmission in the central nervous system.

Neuroprotective Effect of Zataria Multiflora Essential Oil on Rats With Alzheimer Disease: A Mechanistic Study

INTRODUCTION

Finding herbs with promising effects to prevent or postpone Alzheimer Disease (AD) is highly demanded. The present study aimed at clarifying plausible effects and related mechanism(s) of Zataria Multiflora Essential Oil (ZMEO) against memory impairment in a rat model of the AD.

METHODS

Forty male adult rats were categorized into four groups and treated as follows: 1. The Negative Control (NC): no treatment; 2. Sham control (sham): distilled water by Intracerebroventricular (ICV) injection; 3. The AD control (AD): Aβ 1-42 by ICV injection; and 4. The ZMEO group: Aβ 1-42 by ICV injection and ZMEO at 100 μL/kg/d orally for 20 days.

RESULTS

After Congo red staining of the hippocampus, a relative decrease in amyloid deposits was observed in the ZMEO group. Moreover, rats showed better outcomes in Morris Water Maze (MWM) test, reduced hippocampal acetylcholinesterase (AchE) activity, and higher Brain-Derived Neurotrophic Factor (BDNF) content as compared with the AD group (P<0.05). However, no significant changes in antioxidant status was observed (P>0.05).

CONCLUSION

ZMEO has a protective effect against memory impairment in rats with AD at least partly via reducing hippocampal AchE activity and enhancement of BDNF levels without a change in antioxidant status. These findings can pave the way for future studies on the usefulness of this herb in AD prevention.

PROTECTIVE EFFECT OF IRIS GERMANICA L. IN Β-AMYLOID-INDUCED ANIMAL MODEL OF ALZHEIMER'S DISEASE

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia that is an irretrievable chronic neurodegenerative disease. In the current study, we have examined the therapeutic effects of Iris germanica extract on Amyloid β (Aβ) induced memory impairment.

MATERIALS AND METHODS

Wistar rats were divided into five groups of 8 per each. Groups were as followed: control group which were normal rats without induction of AD, Aβ group which received Aβ (50 ng/side), iris 100 group which received Aβ + Iris (100 mg/kg), iris 200 group which received Aβ + Iris (200 mg/kg), and iris 400 group which received Aβ + Iris (400 mg/kg). AD was established by intrahippocampal injection of 50 ng/μl/side Aβ1-42. The day after surgery, animals in treatment groups received different doses of the aqueous extract of Iris by gavage for 30 days. Morris water maze test (MWM) was performed to assess the effects of I. germanica on learning and memory of rats with Aβ induced AD.

RESULTS

Data from MWM tests, including escape latency and traveled distance, demonstrated that I. germanica extract could markedly improve spatial memory in comparison to control. Moreover, the plant had a significantly better effect on the performance of AD rats in the probe test.

CONCLUSION

I. germanica extract can successfully reverse spatial learning dysfunction in an experimental model of AD. Further neuro psyco-pharmacological studies are mandatory to reveal the mechanism of action of this natural remedy in the management of AD symptoms.

Neuroprotective and Anti-Aging Potentials of Essential Oils from Aromatic and Medicinal Plants

The use of essential oils (EOs) and their components is known since long in traditional medicine and aromatherapy for the management of various diseases, and is further increased in the recent times. The neuroprotective and anti-aging potentials of EOs and their possible mechanism of actions were evaluated by numerous researchers around the globe. Several clinically important EOs and their components from Nigella sativa, Acorus gramineus, Lavandula angustifolia, Eucalyptus globulus, Mentha piperita, Rosmarinus officinalis, Jasminum sambac, Piper nigrum and so many other plants are reported for neuroprotective effects. This review article was aimed to summarize the current finding on EOs tested against neurodegenerative disorders like Alzheimer disease (AD) and dementia. The effects of EOs on pathological targets of AD and dementia including amyloid deposition (Aβ), neurofibrillary tangles (NFTs), cholinergic hypofunction, oxidative stress and glutamatergic abnormalities were focused. Furthermore, effects of EOs on other neurological disorders including anxiety, depression, cognitive hypofunction epilepsy and convulsions were also evaluated in detail. In conclusion, EOs were effective on several pathological targets and have improved cognitive performance in animal models and human subjects. Thus, EOs can be developed as multi-potent agents against neurological disorders with better efficacy, safety and cost effectiveness.

Terpenes from Forests and Human Health

Forest bathing has beneficial effects on human health via showering of forest aerosols as well as physical relaxation. Terpenes that consist of multiple isoprene units are the largest class of organic compounds produced by various plants, and one of the major components of forest aerosols. Traditionally, terpene-containing plant oil has been used to treat various diseases without knowing the exact functions or the mechanisms of action of the individual bioactive compounds. This review categorizes various terpenes easily obtained from forests according to their anti-inflammatory, anti-tumorigenic, or neuroprotective activities. Moreover, potential action mechanisms of the individual terpenes and their effects on such processes, which are described in various in vivo and in vitro systems, are discussed. In conclusion, the studies that show the biological effectiveness of terpenes support the benefits of forest bathing and propose a potential use of terpenes as chemotherapeutic agents for treating various human diseases.

Natural products against Alzheimer's disease: Pharmaco-therapeutics and biotechnological interventions

Alzheimer's disease (AD) is a severe, chronic and progressive neurodegenerative disease associated with memory and cognition impairment ultimately leading to death. It is the commonest reason of dementia in elderly populations mostly affecting beyond the age of 65. The pathogenesis is indicated by accumulation of the amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFT) in brain tissues and hyperphosphorylation of tau protein in neurons. The main cause is considered to be the formation of reactive oxygen species (ROS) due to oxidative stress. The current treatment provides only symptomatic relief by offering temporary palliative therapy which declines the rate of cognitive impairment associated with AD. Inhibition of the enzyme acetylcholinesterase (AChE) is considered as one of the major therapeutic strategies offering only symptomatic relief and moderate disease-modifying effect. Other non-cholinergic therapeutic approaches include antioxidant and vitamin therapy, stem cell therapy, hormonal therapy, use of antihypertensive or lipid-lowering medications and selective phosphodiesterase (PDE) inhibitors, inhibition of β-secretase and γ-secretase and Aβ aggregation, inhibition of tau hyperphosphorylation and intracellular NFT, use of nonsteroidal anti-inflammatory drugs (NSAIDs), transition metal chelators, insulin resistance drugs, etanercept, brain-derived neurotrophic factor (BDNF) etc. Medicinal plants have been reported for possible anti-AD activity in a number of preclinical and clinical trials. Ethnobotany, being popular in China and in the Far East and possibly less emphasized in Europe, plays a substantial role in the discovery of anti-AD agents from botanicals. Chinese Material Medica (CMM) involving Chinese medicinal plants has been used traditionally in China in the treatment of AD. Ayurveda has already provided numerous lead compounds in drug discovery and many of these are also undergoing clinical investigations. A number of medicinal plants either in their crude forms or as isolated compounds have exhibited to reduce the pathological features associated with AD. In this present review, an attempt has been made to elucidate the molecular mode of action of various plant extracts, phytochemicals and traditional herbal formulations investigated against AD as reported in various preclinical and clinical tests. Herbal synergism often found in polyherbal formulations were found effective to combat disease heterogeneity as found in complex pathogenesis of AD. Finally a note has been added to describe biotechnological improvement, genetic and genomic resources and mathematical and statistical techniques for empirical model building associated with anti-AD plant secondary metabolites and their source botanicals.

Hippocampal Injections of Oligomeric Amyloid β-peptide (1-42) Induce Selective Working Memory Deficits and Long-lasting Alterations of ERK Signaling Pathway

Increasing evidence suggests that abnormal brain accumulation of soluble rather than aggregated amyloid-β1-42 oligomers (Aβo(1-42)) plays a causal role in Alzheimer's disease (AD). However, as yet, animal's models of AD based on oligomeric amyloid-β1-42 injections in the brain have not investigated their long-lasting impacts on molecular and cognitive functions. In addition, the injections have been most often performed in ventricles, but not in the hippocampus, in spite of the fact that the hippocampus is importantly involved in memory processes and is strongly and precociously affected during the early stages of AD. Thus, in the present study, we investigated the long-lasting impacts of intra-hippocampal injections of oligomeric forms of Aβo(1-42) on working and spatial memory and on the related activation of ERK1/2. Indeed, the extracellular signal-regulated kinase (ERK) which is involved in memory function had been found to be activated by amyloid peptides. We found that repeated bilateral injections (1injection/day over 4 successive days) of oligomeric forms of Aβo(1-42) into the dorsal hippocampus lead to long-lasting impairments in two working memory tasks, these deficits being observed 7 days after the last injection, while spatial memory remained unaffected. Moreover, the working memory deficits were correlated with sustained impairments of ERK1/2 activation in the medial prefrontal cortex (mPFC) and the septum, two brain areas tightly connected with the hippocampus and involved in working memory. Thus, our study is first to evidence that sub-chronic injections of oligomeric forms of Aβo(1-42) into the dorsal hippocampus produces the main sign of cognitive impairments corresponding to the early stages of AD, via long-lasting alterations of an ERK/MAPK pathway in an interconnected brain networks.

The effect of Zataria multiflora Boiss hydroalcoholic extract and fractions in pentylenetetrazole-induced kindling in mice

OBJECTIVE

At present, there are many antiepileptic drugs with a wide range of side effects on the human body. It was assumed that Zataria multiflora Boiss (Z. multiflora) with sedative, anti-spasmodic and anti-inflammatory activity may be effective in the treatment of epilepsy. The aim of the present study was to elucidate the effect of Z. multiflora hydroalcoholic extract and its fraction extracts on pentylenetetrazole (PTZ)-induced chemical kindling.

MATERIALS AND METHODS

In this experimental study, eight separate groups of male albino mice were used. All groups received 11 separate intraperitoneal injections of PTZ (35 mg/kg) with two-day intervals. 30 min before the injection of PTZ, mice received vehicle, Z. multiflora hydroalcoholic extract (300 and 600 mg/kg), n-hexane, acetone, methanol fraction extracts (150 mg/kg), or diazepam (10 mg/kg).

RESULTS

The kindled mice that were pretreated with vehicle showed a gradual increase in their seizure scores up to the end of the study. The hydroalcoholic extract of Z. multiflora (300 and 600 mg/kg) reduced seizure scores significantly. However, n-hexane, acetone and methanol extracts did not affect seizure scores significantly.

CONCLUSION

The present findings demonstrate that the hydroalcoholic extract of Z. multiflora did reduce the severity of seizure attacks in PTZ-induced chemical kindling in mice.

Assessment of anti-amyloidogenic activity of marine red alga G. acerosa against Alzheimer's beta-amyloid peptide 25-35

OBJECTIVE

The amyloid hypothesis stimulates the discovery of compounds, which promotes beta-amyloid peptide (Aβ) clearance, thereby altering the underlying pathophysiology of Alzheimer's disease (AD). Hence, the present study aims at the evaluation of anti-amyloidogenic potential of Gelidiella acerosa.

METHODS

Prevention of Aβ 25-35 aggregate formation and disaggregation of pre-formed fibrils by G. acerosa was evaluated in three phases by thioflavin T spectrophotometric assay. The results were further validated by confocal microscopic analysis. The conformational changes in the aggregated and non-aggregated Aβ in the presence of G. acerosa were analyzed by Fourier transform infrared (FTIR) spectroscopic analysis.

RESULTS

Phase-I study shows that G. acerosa reverts (4.56 ± 0.35 AU at 96 hours) the increase in fluorescence intensity of aggregated Aβ (18.76 ± 0.99 AU) significantly (P < 0.05) as that of non-aggregated peptides, which suggests that G. acerosa prevents the formation of oligomers from monomers. The seaweed also prevents the fibril formation even after the aggregation process was initiated at 20 hours, which was verified by the significant (P < 0.05) decrease in the fluorescence intensity (2.94 ± 0.0721 AU) at 36 hours (Phase II). In addition, G. acerosa promotes fibrillar destabilization (Phase III), which was further substantiated by confocal microscopic analysis. Fourier transform infrared spectroscopy reveals that alteration in amide I and amide II band spectrum, which occurs due to Aβ 25-35 aggregation was restored upon co-treatment with G. acerosa benzene extract.

CONCLUSION

Overall, the results suggest that G. acerosa might have direct interaction with the aggregated peptide, thereby preventing oligomerization and fibrillation of Aβ 25-35.

Effects of Zataria Multi-Flora, Shirazi thyme, on the Severity of Premenstrual Syndrome

Background:

Objectives:

Materials and Methods:

Results:

Conclusions: