Neuroprotective Potential and Underlying Pharmacological Mechanism of Carvacrol for Alzheimer's and Parkinson's Diseases

Comprehensive profiling of traditional herbomineral formulation Manasamitra vatakam in rat brain following oral administration and in-silico screening of the identified compound for anti-Alzheimer's activity

ETHNOPHARMACOLOGICAL RELEVANCE

Multi-targeted drug therapy has received substantial attention for the treatment of diseases of multifactorial origin, such as neurodegenerative diseases. Manasamitra vatakam (MMV) is a traditional Ayurvedic formulation used to improve cognitive impairment and mental illness. Here we have used a unique method for leveraging the barrier properties of the intestinal and blood-brain barrier (BBB) to screen and identify the bioactive molecules against Alzheimer's disease (AD). The current method exemplifies a facile method to expedite drug discovery from traditional formulations.

AIM OF THE STUDY

The present study aimed to identify the phytoconstituents of MMV that reach the brain tissue and to predict major bioactive constituents by computational docking studies.

MATERIALS AND METHODS

After oral administration of the formulation, brain samples from male Sprague Dawley rats were collected at different time intervals and analyzed by liquid chromatography-mass spectrometry (LC-MS) to identify the phytoconstituents. In silico molecular docking studies were carried out to analyze the binding affinity of the compounds to the target proteins of AD using Schrodinger Maestro. The molecular dynamic studies were carried out for all the docked complexes having higher docking scores.

RESULTS

34 phytoconstituents were identified by LC-MS analysis of brain homogenates. In the in silico docking study, the phytoconstituents chrysin, convolvin, rutin, galangin, palmatoside G, isoliquiritigenin, quercetin, and naringenin showed higher docking score against the target proteins of AD. These compounds may serve as the primary bioactive compounds responsible for the neuroprotective activity of the herbal formulation. Furthermore, molecular dynamic studies indicated that the galangin-acetylcholinesterase enzyme complex has the highest stability among these eight compounds.

CONCLUSION

The study, together with previous in vivo and in vitro efficacy results, suggests that BBB-permeable compounds with high binding affinities for the target proteins of AD might be responsible for the effectiveness of MMV against AD.

The inhibitory influence of carvacrol on behavioral modifications, brain oxidation, and general inflammation triggered by paraquat exposure through inhalation

The current study investigated how carvacrol (C) can prevent behavioral and brain oxidative changes, along with systemic inflammation caused by inhaled paraquat (PQ). Control rats exposed to saline solution, whereas six rat groups were subjected to PQ aerosols at a concentration of 54 mg/m3 in 16 days. The PQ-exposed groups received saline (PQ group), C at dosages of 20 (C-L) and 80 mg/kg/day (C-H), dexamethasone at a dosage of 0.03 mg/kg/day, pioglitazone at dose of 5 and 10 mg/kg/day (Pio-L and Pio-H), and a combination of C-L + Pio-L. Various parameters were assessed following the end of the treatment duration. There were marked elevation in total and differential white blood cell counts (WBCs), and malondialdehyde levels in the blood, hippocampus, and cerebral tissue but, thiol, superoxide dismutase (SOD), and catalase (CAT) exhibited a notable decrease (p < 0.05 to p < 0.001). The escape delay and traveled distance exhibited enhancement, however, on the probe day, the duration spent in the target quadrant and the time taken to enter the dark room at 3, 24, 48, and 72 hours post an electrical shock, showed a reduction in the PQ group (P<0.05 to P<0.001). Inhaled PQ-induced changes were significantly improved in C, Pio, Dexa, and C-L + Pio-L treated groups (P<0.05 to P<0.001). The effects of C-L + Pio-L on most measured variables were higher than C-L and Pio-L (P<0.05 to P<0.001). C improved PQ-induced changes similar to dexamethasone and C-L showed additive effects when administered in combination with Pio.

Therapeutic potential of fucoidan in central nervous system disorders: A systematic review

Central nervous system (CNS) disorders have a complicated pathogenesis, and to date, no single mechanism can fully explain them. Most drugs used for CNS disorders primarily aim to manage symptoms and delay disease progression, and none have demonstrated any pathological reversal. Fucoidan is a safe, sulfated polysaccharide from seaweed that exhibits multiple pharmacological effects, and it is anticipated to be a novel treatment for CNS disorders. To assess the possible clinical uses of fucoidan, this review aims to provide an overview of its neuroprotective mechanism in both in vivo and in vitro CNS disease models, as well as its pharmacokinetics and safety. We included 39 articles on the pharmacology of fucoidan in CNS disorders. In vitro and in vivo experiments demonstrate that fucoidan has important roles in regulating lipid metabolism, enhancing the cholinergic system, maintaining the functional integrity of the blood-brain barrier and mitochondria, inhibiting inflammation, and attenuating oxidative stress and apoptosis, highlighting its potential for CNS disease treatment. Fucoidan has a protective effect against CNS disorders. With ongoing research on fucoidan, it is expected that a natural, highly effective, less toxic, and highly potent fucoidan-based drug or nutritional supplement targeting CNS diseases will be developed.

Dietary monoterpenoids and human health: Unlocking the potential for therapeutic use

Natural products are widely used in different aspects of our lives - from household cleaners and food production, via cosmetics and aromatherapy, to both alternative and traditional medicine. In our research group, we have recently described several monoterpenoids with potential in the antiviral and anticancer therapy by allosteric targeting of aryl hydrocarbon receptor (AhR). Prior to any practical application, biological effects on human organism must be taken in concern. This review article is focused on the biological effects of 5 monoterpenoids on the human health previously identified as AhR antagonists with a therapeutic potential as antiviral and anticancer agents. We have thoroughly described cytotoxic, anti-inflammatory, anti-proliferative, and anticancer effects, as well as known interactions with nuclear receptors. As clearly demonstrated, monoterpenoids in general represent almost an inexhaustible reservoir of natural compounds possessing the ability to influence, modulate and improve human health.

Antioxidants as Protection against Reactive Oxygen Stress Induced by Formaldehyde (FA) Exposure: A Systematic Review

BACKGROUND AND OBJECTIVES

Formaldehyde induces oxidative stress and is carcinogenic, particularly squamous cell carcinoma of the nasopharyngeal area. Around us, in exhaust gases, cigarette smoke, and various industrial products, FA primarily affects the respiratory tract and other organs like the cornea, liver, kidneys, brain, and cardiovascular system. This study aims to determine if antioxidants can mitigate FA's harmful effects.

MATERIALS AND METHODS

Several databases, including PubMed, Science Direct, Springer, and Wiley, were systematically searched. Research publications on antioxidants mitigating FA-induced oxidative damage were included, but reviews and articles lacking complete texts were excluded. SYRCLE's risk of bias tool for animal studies has been used. Tables were used for data synthesis. Out of 8790 articles, 35 publications detailing tissue homogenate for biochemical analysis, standard hematoxylin-eosin staining, and immunohistochemistry markers for histopathological and immunohistochemical diagnosis were selected. Most studies were case-control studies, utilizing rat or mouse models. Additionally, one cohort study on industrial workers was analyzed.

CONCLUSIONS

Antioxidants, including plant extracts, vitamins, and pigments, can prevent or heal FA-induced lesions. However, human studies, particularly biopsies, remain challenging, and animal trials are limited. Further research is needed to confirm FA's long-term effects and optimize antioxidant dosages.

Exposure estimation and neurotoxicity inhibition of dioxins in sensitive populations near domestic waste incineration plant through adverse outcome pathway

The neurotoxicity induced by dioxins has been recognized as a serious concern to sensitive population living near waste incineration plants. However, investigating the intracellular neurotoxicity of dioxin in humans and the corresponding mitigation strategies has been barely studied. Thus, a domestic waste incineration plant was selected in this study to characterize the neurotoxicity risks of sensitive populations by estimating the ratio of dioxin in human cells using membrane structure dynamics simulation; and constructing a complete dioxin neurotoxicity adverse outcome pathway considering the binding process of AhR/ARNT dimer protein and dioxin response element (DRE). Six dioxins with high neurotoxicity risk were identified. According to the composite neurotoxicity risk analysis, the highest composite neurotoxicity risk appeared when the six dioxins were jointly exposed. Dietary schemes were designed using 1/2 partial factor experimental design to mitigate the composite neurotoxicity risk of six dioxins and No. 16 was screened as the optimum combination which can effectively alleviate the composite neurotoxicity risk by 29.52%. Mechanism analysis shows that the interaction between AhR/ARNT dimer protein and DRE was inhibited under the optimal dietary scheme. This study provides theoretical feasibility and reference significance for assessing composite toxicity risks of pollutants and safety mitigation measures for toxic effects.

Anti-insomnia Effect of a Polyherbal Formulation on P-chlorophenyalanine Induced Experimental Animal Model

Sleep is a dynamic and controlled set of physiological and behavioural practices during which the stabilisation and restoration processes of the body take place properly. Therefore, sleep disorders, especially chronic insomnia, can harm an individual's physical and mental health. However, the therapeutic alternatives are limited and possess severe side effects. Thus, in this study, we aimed to investigate the anti-insomnia effect of a polyherbal formulation (Sleep) (SLP) on p-chlorophenyalanine (PCPA) induced insomnia in rats. Intraperitoneal injection of PCPA induced the experimental condition, and the therapeutic effect of SLP was evaluated by studying the sleep pattern and expression of various neurotransmitters and receptors, along with neurotrophins. Moreover, insomnia-associated oxidative stress and inflammation were also studied. From the findings, we found that the SLP-supplemented animals improved their sleeping behaviour and that the major neurotransmitters, hormones, and receptors were maintained at an equilibrium level. Furthermore, the neurotrophin level was increased and pro-inflammatory cytokines were reduced. The evaluation of oxidative stress markers shows that the antioxidants were significantly boosted, and as a result, lipid peroxidation was prevented. The overall findings suggest that SLP can be used as an effective medication for the treatment of sleep disorders like insomnia as it triggers the major neurotransmitter system.

Essential Oil Molecules Can Break the Loop of Oxidative Stress in Neurodegenerative Diseases

Essential oils (EOs) are mixtures of volatile compounds, extracted from aromatic plants, with multiple activities including antioxidant and anti-inflammatory ones. EOs are complex mixtures easy to find on the market and with low costs. In this mini narrative review, we have collected the results of in vitro and in vivo studies, which tested these EOs on validated models of neurodegeneration and in particular of the two main neurodegenerative diseases (NDs) that afflict humans: Alzheimer's and Parkinson's. Since EO compositions can vary greatly, depending on the environmental conditions, plant cultivar, and extraction methods, we focused our attention to studies involving single EO molecules, and in particular those that have demonstrated the ability to cross the blood-brain barrier. These single EO molecules, alone or in defined mixtures, could be interesting new therapies to prevent or slow down oxidative and inflammatory processes which are common mechanisms that contribute to neuronal death in all NDs.

Therapeutic Potential of Myrtenal and Its Derivatives-A Review

The investigation of monoterpenes as natural products has gained significant attention in the search for new pharmacological agents due to their ability to exhibit a wide range in biological activities, including antifungal, antibacterial, antioxidant, anticancer, antispasmodic, hypotensive, and vasodilating properties. In vitro and in vivo studies reveal their antidepressant, anxiolytic, and memory-enhancing effects in experimental dementia and Parkinson's disease. Chemical modification of natural substances by conjugation with various synthetic components is a modern method of obtaining new biologically active compounds. The discovery of new potential drugs among monoterpene derivatives is a progressive avenue within experimental pharmacology, offering a promising approach for the therapy of diverse pathological conditions. Biologically active substances such as monoterpenes, for example, borneol, camphor, geraniol, pinene, and thymol, are used to synthesize compounds with analgesic, anti-inflammatory, anticonvulsive, antidepressant, anti-Alzheimer's, antiparkinsonian, antiviral and antibacterial (antituberculosis) properties. Myrtenal is a perspective monoterpenoid with therapeutic potential in various fields of medicine. Its chemical modifications often lead to new or more pronounced biological effects. As an example, the conjugation of myrtenal with the established pharmacophore adamantane enables the augmentation of several of its pivotal properties. Myrtenal-adamantane derivatives exhibited a variety of beneficial characteristics, such as antimicrobial, antifungal, antiviral, anticancer, anxiolytic, and neuroprotective properties, which are worth examining in more detail and at length.