Neuroprotective effect of berberine agonist against impairment of learning and memory skills in severe traumatic brain injury via Sirt1/p38 MAPK expression

The neuroprotective potential of phytochemicals in traumatic brain injury: mechanistic insights and pharmacological implications

Traumatic brain injury (TBI) leads to brain damage, comprising both immediate primary damage and a subsequent cascade of secondary injury mechanisms. The primary injury results in localized brain damage, while the secondary damage initiates inflammatory responses, followed by the disruption of the blood-brain barrier, infiltration of peripheral blood cells, brain edema, and the release of various immune mediators, including chemotactic factors and interleukins. TBI disrupts molecular signaling, cell structures, and functions. In addition to physical tissue damage, such as axonal injuries, contusions, and haemorrhages, TBI interferes with brain functioning, impacting cognition, decision-making, memory, attention, and speech capabilities. Despite a deep understanding of the pathophysiology of TBI, an intensive effort to evaluate the underlying mechanisms with effective therapeutic interventions is imperative to manage the repercussions of TBI. Studies have commenced to explore the potential of employing natural compounds as therapeutic interventions for TBI. These compounds are characterized by their low toxicity and limited interactions with conventional drugs. Moreover, many natural compounds demonstrate the capacity to target various aspects of the secondary injury process. While our understanding of the pathophysiology of TBI, there is an urgent need for effective therapeutic interventions to mitigate its consequences. Here, we aimed to summarize the mechanism of action and the role of phytochemicals against TBI progression. This review discusses the therapeutic implications of various phytonutrients and addresses primary and secondary consequences of TBI. In addition, we highlighted the roles of emerging phytochemicals as promising candidates for therapeutic intervention of TBI. The review highlights the neuroprotective roles of phytochemicals against TBI and the mechanistic approach. Furthermore, our efforts focused on the underlying mechanisms, providing a better understanding of the therapeutic potential of phytochemicals in TBI therapeutics.

Role of SIRT1 in sepsis-induced encephalopathy: Molecular targets for future therapies

Sepsis induces neuroinflammation, BBB disruption, cerebral hypoxia, neuronal mitochondrial dysfunction, and cell death causing sepsis-associated encephalopathy (SAE). These pathological consequences lead to short- and long-term neurobehavioural deficits. Till now there is no specific treatment that directly improves SAE and its associated behavioural impairments. In this review, we discuss the underlying mechanisms of sepsis-induced brain injury with a focus on the latest progress regarding neuroprotective effects of SIRT1 (silent mating type information regulation-2 homologue-1). SIRT1 is an NAD+ -dependent class III protein deacetylase. It is able to modulate multiple downstream signals (including NF-κB, HMGB, AMPK, PGC1α and FoxO), which are involved in the development of SAE by its deacetylation activity. There are multiple recent studies showing the neuroprotective effects of SIRT1 in neuroinflammation related diseases. The proposed neuroprotective action of SIRT1 is meant to bring a promising therapeutic strategy for managing SAE and ameliorating its related behavioural deficits.

Berberine suppressed sarcopenia insulin resistance through SIRT1-mediated mitophagy

Abnormal mitochondrial function resulting in inadequate energy supply leads to sarcopenia and IR, suggesting that maintaining mitochondrial homeostasis by regulating mitophagy may be a promising strategy for sarcopenia IR therapy. Herein, we constructed sarcopenia mice model, which was treated with berberine and/or SIRT1/mitophagy inhibitors, and the activity of SIRT1/mitophagy signaling pathway was identified. Then, muscle tissue, blood biochemical index, inflammatory factors, GTT, and ITT were detected. We found that berberine treatment increased the body weight and alleviated d-galactose-induced weight loss in mice. SIRT1/mitophagy inhibitors suppressed the effects of berberine in the treatment of sarcopenia. The effect of berberine on the increase of muscle tissue, improving metabolic disorders, reducing the expression of inflammatory factors, and suppressing sarcopenia insulin resistance (IR) were reversed by SIRT1/mitophagy inhibitors. Our study establishes proof-of-concept to distinct the effect of berberine in sarcopenia IR, and provides strong evidence to support the hypothesis that berberine-induced SIRT1 triggers mitochondrial autophagy pathway and suppresses IR in sarcopenia.

Berberine as a natural modulator of inflammatory signaling pathways in the immune system: Focus on NF-κB, JAK/STAT, and MAPK signaling pathways

Three main inflammatory signaling pathways include nuclear factor-κB (NF-κB), Janus kinases/Signal transducer and activator of transcriptions (JAKs/STATs), and mitogen-activated protein kinases (MAPKs) play crucial roles in inducing, promoting, and regulating inflammatory responses in the immune system. Importantly, the breakdown of mechanisms that tightly regulate inflammatory signaling pathways can be the underlying cause of uncontrolled inflammatory responses and be associated with the generation and development of several inflammatory diseases. Hence, therapeutic strategies targeting inflammatory signaling pathways and their downstream components may promise to treat inflammatory diseases. Studies over the past two decades have provided important information on the polytrophic pharmacological and biochemical properties of berberine (BBR) as a naturally occurring compound, such as antioxidant, antitumor, antimicrobial, and antiinflammatory activates. Interestingly, the modulatory effects of BBR on inflammatory signaling cascades, which lead to the inhibition of inflammation, have been widely investigated in several in vitro and in vivo studies. For the first time, herein, this comprehensive review attempts to put together these studies and provide important insight into the modulatory effects of BBR on NF-κB, JAKs/STATs, and MAPKs signaling pathways in vitro in various types of immune cells and in vivo in several experimental inflammatory diseases. As the second achievement of this review, we also explore the therapeutic efficacy and antiinflammatory effects of BBR regarding its modulatory action.

Neuroprotective Potential of Berberine Against Doxorubicin-Induced Toxicity in Rat's Brain

Chemotherapy-associated neurotoxicity is one of the principal side-effects for doxorubicin (DOX)-treated cancer patients. Despite its poor-penetration across the blood-brain barrier (BBB), DOX is linked to the induction of oxidative stress and neuroinflammation. Berberine (BEB) is a natural polyphenolic alkaloid, which exhibits unique antioxidant activity and anti-inflammatory potential. The present study was performed to investigate the neuroprotective potential of BEB in a rodent model of DOX-induced neurotoxicity. Neurotoxicity was induced in rats via a single acute dose of DOX (20 mg/kg/week, i.p.). BEB was administered at 50 mg/kg/day orally for 10 days before and 4 days after DOX administration. Brain acetylcholinesterase (AChE) activities were evaluated. Oxidative stress was investigated via the colorimetric determination of lipid peroxides, glutathione reduced (GSH) contents and catalase (CAT) activities in the brain tissue. In addition, DOX-induced genotoxicity was evaluated using comet assay. DOX produced a significant elevation in AChE activities. Additionally, DOX provoked oxidative stress as evidenced from the significant elevation in lipid peroxidation along with depletion in GSH contents and CAT activities. Moreover, DOX resulted in neuroinflammation as indicated by the elevation of pro-inflammatory mediator glial fibrillary acid protein (GFAP), as well as, the pro-apoptotic nuclear factor kappa B (NF-κB) and caspase-3 in brain tissue. Co-treatment with BEB significantly counteracted DOX-induced oxidative stress, neuroinflammation and genotoxicity. Histopathological and immunohistochemical examination supported the biochemical results. BEB demonstrated neuroprotective potential through exerting cholinergic, anti-oxidative, genoprotective, anti-inflammatory, and anti-apoptotic activities. Our findings present BEB as a promising "pre-clinical" neuroprotective agent against DOX-induced neurotoxicity during anti-neoplastic therapy.

The Beneficial Roles of SIRT1 in Neuroinflammation-Related Diseases

Sirtuins are the class III of histone deacetylases whose deacetylate of histones is dependent on nicotinamide adenine dinucleotide (NAD+). Among seven sirtuins, SIRT1 plays a critical role in modulating a wide range of physiological processes, including apoptosis, DNA repair, inflammatory response, metabolism, cancer, and stress. Neuroinflammation is associated with many neurological diseases, including ischemic stroke, bacterial infections, traumatic brain injury, Alzheimer's disease (AD), and Parkinson's disease (PD). Recently, numerous studies indicate the protective effects of SIRT1 in neuroinflammation-related diseases. Here, we review the latest progress regarding the anti-inflammatory and neuroprotective effects of SIRT1. First, we introduce the structure, catalytic mechanism, and functions of SIRT1. Next, we discuss the molecular mechanisms of SIRT1 in the regulation of neuroinflammation. Finally, we analyze the mechanisms and effects of SIRT1 in several common neuroinflammation-associated diseases, such as cerebral ischemia, traumatic brain injury, spinal cord injury, AD, and PD. Taken together, this information implies that SIRT1 may serve as a promising therapeutic target for the treatment of neuroinflammation-associated disorders.

Proteomic profiling of the neurons in mice with depressive-like behavior induced by corticosterone and the regulation of berberine: pivotal sites of oxidative phosphorylation

Chronic corticosterone (CORT) stress is an anxiety and depression inducing factor that involves the dysfunction of glucocorticoid receptor (GR), brain-derived neurotrophic factor (BDNF), and neuronal plasticity. However, the regulation of proteomic profiles in neurons suffering CORT stress is remaining elusive. Thus, the proteomic profiles of mouse neuronal C17.2 stem cells were comprehensively investigated by TMT (tandem mass tag)-labeling quantitative proteomics. The quantitative proteomics conjugated gene ontology analysis revealed the inhibitory effect of CORT on the expression of mitochondrial oxidative phosphorylation-related proteins, which can be antagonized by berberine (BBR) treatment. In addition, animal studies showed that changes in mitochondria by CORT can affect neuropsychiatric activities and disturb the physiological functions of neurons via disordering mitochondrial oxidative phosphorylation. Thus, the mitochondrial energy metabolism can be considered as one of the major mechanism underlying CORT-mediated depression. Since CORT is important for depression after traumatic stress disorder, our study will shed light on the prevention and treatment of depression as well as posttraumatic stress disorder (PTSD).

Berberine ameliorates lipopolysaccharide-induced learning and memory deficit in the rat: insights into underlying molecular mechanisms

Systemic lipopolysaccharide (LPS) triggers neuroinflammation with consequent development of behavioral and cognitive deficits. Neuroinflammation plays a crucial role in the pathogenesis of neurodegenerative disorders including Alzheimer's disease (AD). Berberine is an isoquinoline alkaloid in Berberis genus with antioxidant and anti-inflammatory property and protective effects in neurodegenerative disorders. In this research, beneficial effect of this alkaloid against LPS-induced cognitive decline was assessed in the adult male rats. LPS was intraperitoneally administered at a dose of 1 mg/kg to induce neuroinflammation and berberine was given via gavage at doses of 10 or 50 mg/kg, one h after LPS, for 7 days. Treatment of LPS group with berberine at a dose of 50 mg/kg (but not at a dose of 10 mg/kg) improved spatial recognition memory in Y maze, performance in novel object recognition task (NORT), and prevented learning and memory dysfunction in passive avoidance tasks. Furthermore, berberine lowered hippocampal activity of acetylcholinesterase (AChE), malondialdehyde (MDA), protein carbonyl, activity of caspase 3, and DNA fragmentation and improved antioxidant capacity through enhancing glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase, and glutathione (GSH). Besides, berberine attenuated inflammation-related indices, as was evident by lower levels of nuclear factor-kappa B (NF-κB), toll-like receptor 4 (TLR4), tumor necrosis factor α (TNFα), and interleukin 6 (IL-6). Berberine also appropriately restored hippocampal 3-nitrotyrosine (3-NT), cyclooxygenase 2 (Cox 2), glial fibrillary acidic protein (GFAP), sirtuin 1, and mitogen-activated protein kinase (p38 MAPK) with no significant alteration of brain-derived neurotrophic factor (BDNF). In summary, berberine could partially ameliorate LPS-induced cognitive deficits via partial suppression of apoptotic cascade, neuroinflammation, oxido-nitrosative stress, AChE, MAPK, and restoration of sirtuin 1.

Berberine Protects Secondary Injury in Mice with Traumatic Brain Injury Through Anti-oxidative and Anti-inflammatory Modulation

Traumatic brain injury (TBI) is one of the major causes of death and disability worldwide. Novel and effective therapy is needed to prevent the secondary spread of damage beyond the initial injury. The aim of this study was to investigate whether berberine has a neuroprotective effect on secondary injury post-TBI, and to explore its potential mechanism in this protection. The mice were randomly divided into Sham-saline, TBI-saline and TBI-Berberine (50 mg/kg). TBI was induced by Feeney's weight-drop technique. Saline or berberine was administered via oral gavage starting 1 h post-TBI and continuously for 21 days. Motor coordination, spatial learning and memory were assessed using beam-walking test and Morris water maze test, respectively. Brain sections were processed for lesion volume assessment, and expression of neuronal nuclei (NeuN), cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS), 8-hydroxy-2-deoxyguanosine (8-OHdG), ionized calcium-binding adapter molecule 1 (Iba1) and glial fibrillary acidic protein (GFAP) were detected via immunohistochemistry and immunofluorescence. There were statistically significant improvement in motor coordination, spatial learning and memory in the TBI-Berberine group, compared to the TBI-saline group. Treatment with berberine significantly reduced cortical lesion volume, neuronal loss, COX-2, iNOS and 8-OHdG expression in both the cortical lesion border zone (LBZ) and ipsilateral hippocampal CA1 region (CA1), compared to TBI-saline. Berberine treatment also significantly decreased Iba1- and GFAP-positive cell number in both the cortical LBZ and ipsilateral CA1, relative to saline controls. These results indicated that berberine exerted neuroprotective effects on secondary injury in mice with TBI probably through anti-oxidative and anti-inflammatory properties.