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

Gallic acid alleviates ferroptosis by negatively regulating APOC3 and improves nerve function deficit caused by traumatic brain injury

Traumatic brain injury (TBI) is more common than ever and is becoming a global public health issue. A variety of secondary brain injuries occur after TBI, including ferroptosis characterized by iron-dependent lipid peroxidation. Gallic acid is a kind of traditional Chinese medicine, which has many biological effects such as anti-inflammatory and antioxidant. We further investigated whether Gallic acid can improve the neurological impairment caused by ferroptosis after TBI by targeting APOC3. Weighted gene coexpression network analyses (WGCNA) and 3 kinds of machine-learning algorithms were used to find the potential biomarkers. Then the HERB database was used to select the Chinese herb that acted on the target gene APOC3. Finally, we selected Gallic acid as a drug targeting APOC3 and verified by Western blotting. The effect of Gallic acid on the improvement of neurological function was studied by Nissl staining and FJB staining. Finally, the effect of Gallic acid on the cognitive ability of TBI mice was explored through behavioral experiments. Gallic acid can inhibit the expression level of APOC3 and thus inhibit the level of ferroptosis after TBI. It can also reduce the degeneration of nerve tissue by inhibiting ferroptosis and improve the neurological function deficit. The behavioral experiment proved that Gallic acid can alleviate the behavioral cognitive impairment caused by TBI. Gallic acid can reduce ferroptosis by inhibiting APOC3, and then alleviate neurological impairment after TBI.

Much More than Nutrients: The Protective Effects of Nutraceuticals on the Blood-Brain Barrier in Diseases

The dysfunction of the blood-brain barrier (BBB) is well described in several diseases, and is considered a pathological factor in many neurological disorders. This review summarizes the most important groups of natural compounds, including alkaloids, flavonoids, anthocyanidines, carotenoids, lipids, and vitamins that were investigated for their potential protective effects on brain endothelium. The brain penetration of these compounds and their interaction with BBB efflux transporters and solute carriers are discussed. The cerebrovascular endothelium is considered a therapeutic target for natural compounds in diseases. In preclinical studies modeling systemic and central nervous system diseases, nutraceuticals exerted beneficial effects on the BBB. In vivo, they decreased BBB permeability, brain edema, astrocyte swelling, and morphological changes in the vessel structure and basal lamina. At the level of brain endothelial cells, nutraceuticals increased cell survival and decreased apoptosis. From the general endothelial functions, decreased angiogenesis and increased levels of vasodilating agents were demonstrated. From the BBB functions, elevated barrier integrity by tightened intercellular junctions, and increased expression and activity of BBB transporters, such as efflux pumps, solute carriers, and metabolic enzymes, were shown. Nutraceuticals enhanced the antioxidative defense and exerted anti-inflammatory effects at the BBB. The most important signaling changes mediating the increased cell survival and BBB stability were the activation of the WNT, PI3K-AKT, and NRF2 pathways, and inhibition of the MAPK, JNK, ERK, and NF-κB pathways. Nutraceuticals represent a valuable source of new potentially therapeutic molecules to treat brain diseases by protecting the BBB.

Pterostilbene protects against lipopolysaccharide-induced inflammation and blood-brain barrier disruption in immortalized brain endothelial cell lines in vitro

Brain microvascular endothelial cells are connected by tight junction (TJ) proteins and interacted by adhesion molecules, which participate in the selective permeability of the blood-brain barrier (BBB). The disruption of BBB is associated with the progression of cerebral diseases. Pterostilbene is a natural compound found in blueberries and grapes with a wide range of biological activities, including anti-inflammatory, antioxidant, and anti-diabetic effects. In this study, we investigated the protective effects of pterostilbene on LPS-stimulated mouse brain endothelial (bEnd.3) cells and underlying mechanisms. The results showed that pterostilbene effectively upregulated the expressions of tight junction (TJ) proteins such as zonula occludens (ZO)-1 and claudin-5 and downregulated the expression of adhesion molecules such as intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1, preventing BBB damage under LPS stimulation. Pterostilbene decreased the LPS-triggered expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 as well as the levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α and nitric oxide (NO). Meanwhile, we found that pterostilbene exerted an inhibitory effect on nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in bEnd.3 cells upon LPS stimulation. Additionally, pterostilbene exhibited antioxidant effects by activating heme oxygenase 1 (HO-1). These findings indicated that pterostilbene protected against lipopolysaccharide (LPS)-induced inflammation, oxidative stress and blood-brain barrier (BBB) disruption in bEnd.3 cells.

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.

Neuroinflammatory Response in the Traumatic Brain Injury: An Update

The central nervous system (CNS) comprises membranes and barriers that are vital to brain homeostasis. Membranes form a robust shield around neural structures, ensuring protection and structural integrity. At the same time, barriers selectively regulate the exchange of substances between blood and brain tissue, which is essential for maintaining homeostasis. Another highlight is the glymphatic system, which cleans metabolites and waste from the brain. Traumatic brain injury (TBI) represents a significant cause of disability and mortality worldwide, resulting from the application of direct mechanical force to the head that results in a primary injury. Therefore, this review aims to elucidate the mechanisms associated with the secondary injury cascade, in which there is intense activation of glial cells, dysfunction of the glymphatic system, glutamatergic neurotoxicity, additional molecular and biochemical changes that lead to a neuroinflammatory process, and oxidative stress and in which way they can be associated with cognitive damage that is capable of lasting for an extended period.

Management of the Brain: Essential Oils as Promising Neuroinflammation Modulator in Neurodegenerative Diseases

Neuroinflammation, a pivotal factor in the pathogenesis of various brain disorders, including neurodegenerative diseases, has become a focal point for therapeutic exploration. This review highlights neuroinflammatory mechanisms that hallmark neurodegenerative diseases and the potential benefits of essential oils in counteracting neuroinflammation and oxidative stress, thereby offering a novel strategy for managing and mitigating the impact of various brain disorders. Essential oils, derived from aromatic plants, have emerged as versatile compounds with a myriad of health benefits. Essential oils exhibit robust antioxidant activity, serving as scavengers of free radicals and contributing to cellular defense against oxidative stress. Furthermore, essential oils showcase anti-inflammatory properties, modulating immune responses and mitigating inflammatory processes implicated in various chronic diseases. The intricate mechanisms by which essential oils and phytomolecules exert their anti-inflammatory and antioxidant effects were explored, shedding light on their multifaceted properties. Notably, we discussed their ability to modulate diverse pathways crucial in maintaining oxidative homeostasis and suppressing inflammatory responses, and their capacity to rescue cognitive deficits observed in preclinical models of neurotoxicity and neurodegenerative diseases.