Alleviation of Memory Deficit by Bergenin via the Regulation of Reelin and Nrf-2/NF-κB Pathway in Transgenic Mouse Model

Therapeutic potential of Bergenin in the management of neurological-based diseases and disorders

Originally sourced from plants, Bergenin has been used as a medicinal compound in traditional medicine for centuries, and anecdotal reports suggest a wide range of therapeutic uses. Naturally-occurring and lab-synthesized Bergenin, as well as some of its related compounds, have been shown in in vivo and in vitro studies to alter activity of several enzymes and proteins critical in cellular functioning, including reelin, GSK-3β, Lingo-1, Ten-4, GP-43, Aβ 1-42, P-tau, SOD1,2, GPx, Glx1, NQO1, HO1, PPAR-ɣ, BDNF, VEGF, and STAT6. Additionally, Bergenin alters levels of several cytokines, such as IL-6, IL-1β, TNF-α, and TGF-β. Behavioral and cellular effects of Bergenin have been shown to involve PI3K/Akt, NF-κB, PKC, Nrf2, and Sirt1/FOXO3a pathways. These pathways, enzymes, and proteins have been shown to be important in normal neurological functioning, and/or dysfunctions in these pathways and proteins have been shown to be important in several neuro-based disorders or diseases, which suggests that Bergenin could be therapeutic in management of neuropsychiatric conditions or neurological disorders. In preclinical studies, Bergenin has been shown to be useful for the management of Alzheimer's disease, Parkinson's disease, anxiety, depression, addiction, epilepsy, insomnia, stroke, and potentially, state control. Our review aims to summarize current evidence supporting the conclusion that Bergenin could play a role in treating various neuro-based disorders and that future studies should be conducted to evaluate the mechanisms by which Bergenin could exert its therapeutic effects.

Quantitative investigation of drug-drug interaction between bergenin and vilazodone in rats through UPLC-MS/MS assay

In this study, we firstly established and verified a method by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the analysis of vilazodone and its metabolite M10 in rat plasma, then this method was used to explore the pharmacokinetics of vilazodone and M10 present or absence of 80 mg/kg bergenin in rats. Protein precipitation with acetonitrile was used to prepare the samples in this research. The mobile phase for liquid chromatography was consisted of 0.1% formic acid aqueous solution and acetonitrile. Brexpiprazole was used as the internal standard (IS), and the multiple reaction monitoring (MRM) mode was used for detection. The verification items required by the US Food and Drug Administration (FDA) guidelines such as selectivity, sensitivity, linearity, stability, recovery and matrix effect of this method were all met the standards. Besides, rats were used to explore the drug-drug interaction between vilazodone and bergenin, which were divided into two groups, and separately gavaged with the same-volume of carboxymethyl cellulose sodium (CMC-Na) solution and 80 mg/kg bergenin, respectively. The results showed that bergenin significantly affected the metabolism of vilazodone. It suggested that there was a potential drug-drug interaction between bergenin and vilazodone in rats. In clinical application, we should pay attention to the dose of vilazodone when in combination with bergenin.

Preparation, characterization, and pharmacological application of oral Honokiol-loaded solid lipid nanoparticles for diabetic neuropathy

Honokiol is a phytochemical component with a variety of pharmacological properties. However, the major limitation of Honokiol is its poor solubility and low oral bioavailability. In this study, we formulated and characterized oral Honokiol-loaded solid lipid nanoparticles (SLNs) to enhance bioavailability and then evaluated their effectiveness in experimental diabetic neuropathy (DN). The finalized formulation has a spherical morphology, a particle size (PS) of 121.31 ± 9.051 nm, a polydispersity index (PDI) of 0.249 ± 0.002, a zeta potential (ZP) of -20.8 ± 2.72 mV, and an entrapment efficiency (% EE) of 88.66 ± 2.30 %. In-vitro release data shows, Honokiol-SLNs displayed a sustained release profile at pH (7.4). The oral bioavailability of Honokiol-SLNs was remarkably greater (8-fold) than Honokiol-Pure suspension. The neuroprotective property of Honokiol-SLNs was initially demonstrated against hydrogen peroxide H2O2-stimulated PC12 (pheochromocytoma) cells. Furthermore, results of in-vivo studies demonstrated that treatment with Honokiol-SLNs significantly (p < 0.001) suppressed oxidative stress by inhibition of nuclear factor kappa B (NF-κB) and significant (p < 0.001) upregulation of nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling in the spinal cord. The expression of transient receptor potential melastatin 8(TRPM8) and transient receptor potential vanilloid 1 (TRPV1) was significantly (p < 0.001) downregulated. Honokiol-SLNs inhibited apoptosis by significant (p < 0.001) downregulation of cleaved caspase-3 expression in the spinal cord. These findings demonstrate that Honokiol-SLNs providedbetter neuroprotection in DN because of higher oral bioavailability.

Dual pH and microbial-sensitive galactosylated polymeric nanocargoes for multi-level targeting to combat ulcerative colitis

Ulcerative colitis (UC) is a type of inflammatory bowel disease characterized by inflammation, ulcers and irritation of the mucosal lining. Oral drug delivery in UC encounters challenges because of multifaceted barriers. Dexamethasone-loaded galactosylated-PLGA/Eudragit S100/pullulan nanocargoes (Dexa-GP/ES/Pu NCs) have been developed with a dual stimuli-sensitive coating responsive to both colonic pH and microbiota, and an underneath galactosylated-PLGA core (GP). The galactose ligand of the GP preferentially binds to the macrophage galactose type-lectin-C (MGL-2) surface receptor. Therefore, both stimuli and ligand-mediated targeting facilitate nanocargoes to deliver Dexa specifically to the colon with enhanced macrophage uptake. Modified emulsion method coupled with a solvent evaporation coating technique was employed to prepare Dexa-GP/ES/Pu NCs. The nanocargoes were tested using in vitro, ex vivo techniques and dextran sodium sulfate (DSS) induced UC model. Prepared nanocargoes had desired physicochemical properties, drug release, cell uptake and cellular viability. Investigations using a DSS-colitis model showed high localization and mitigation of colitis with downregulation of NF-ĸB and COX-2, and restoration of clinical, histopathological, biochemical indices, antioxidant balance, microbial alterations, FTIR spectra, and epithelial junctions' integrity. Thus, Dexa-GP/ES/Pu NCs found to be biocompatible nanocargoes capable of delivering drugs to the inflamed colon with unique targeting properties for prolonged duration.

Neuroprotective mechanism of Ajugarin-I against Vincristine-Induced neuropathic pain via regulation of Nrf2/NF-κB and Bcl2 signalling

Vincristine (VCR) is a well-known chemotherapeutic agent that frequently triggers neuropathic pain. Ajugarin-I (Aju-I) isolated from Ajuga bracteosa exerts antioxidant, anti-inflammatory, and neuroprotective properties. The present study was designed to investigate the ameliorative potential of Aju-I against VCR-induced neuropathic pain and explored the underlying mechanism involved. The neuroprotective potential of Aju-I was first confirmed against hydrogen peroxide (H₂O₂)-induced cytotoxicity and oxidative stress in PC12 cells. For neuropathic pain induction, vincristine was given intraperitoneally (i.p.) into adult male albino mice (BALB/c) of the same age (8-12 weeks old) for 10 days (days 1-10). Aju-I (1 and 5 mg/kg) doses were administered from day 11 to 21 intraperitoneally (i.p.) after the neuropathic induction. Initially, behavioral tests such as thermal hyperalgesia, mechanical allodynia, and cold allodynia were performed to investigate the antinociceptive potential of Ajugarin-I (1 and 5 mg/kg, b.w). The nuclear factor-erythroid factor 2-related factor 2(Nrf2), nuclear factor-κB (NF-κB), BCL2-associated × protein (Bax), and B-cell-lymphoma-2 (Bcl-2) signaling proteins were determined by immunohistochemistry and western blot. Additionally, inflammatory cytokines, antioxidant, and oxidative stress parameters were also measured in the spinal cord and sciatic nerve. The behavioral results demonstrated that Aju-I (5 mg/kg) markedly alleviated VCR-induced neuropathic pain behaviors including hyperalgesia and allodynia. It reversed the histological alterations caused by VCR in the sciatic nerve, spinal cord, and brain. It significantly alleviated oxidative stress and inflammation by regulating the immunoreactivity of Nrf2/NF-κB signaling. It suppressed apoptosis by regulating the immunoreactivity of Bcl-2/Bax and Caspase-3. The flow cytometry and comet analysis also confirmed its anti-apoptotic potential. It considerably improved the antioxidant status and mitigated VCR-induced inflammatory cytokines. High-performance liquid chromatography (HPLC) analysis indicated that Aju-I crosses the blood-brain barrier (BBB) and penetrated the brain tissue. These findings suggest that Aju-I treatment inhibited vincristine-induced neuropathy via regulation of Nrf2/NF-κB and Bcl2 signaling.

Comparative appraisal of in vitro biological profile and in vivo wound healing attributes of bergenin and Bergenia ciliata (Haw.) Sternb

ETHNOPHARMACOLOGICAL RELEVANCE

People of all ages experience injuries, whether mild or severe. The most available option to treat wounds as an alternative to allopathic care in both urban and rural populations is traditional medicine, which is mostly target inflammation. Bergenia ciliata (Haw.) Sternb rhizome and leaf powder are used in Ayurveda and local communities for various ailments including healing of wounds and burns. Owing to this property it is traditionally known as "Zakham-e-hayat" (wound healer).

AIM OF THE STUDY

In the present study, we compared biological activity and wound healing potential of B. ciliata rhizome (R) extract and bergenin, a glycoside isolated from B. ciliata.

MATERIALS AND METHODS

Reverse-phase high performance liquid chromatography (RP-HPLC) was performed to analyze polyphenols and bergenin in B. ciliata R extract. Samples were subjected to in vitro antioxidant assays including free radical scavenging, ferric chloride reducing power and total antioxidant capacity. Micro-broth dilution method, brine shrimp lethality assay and isolated RBC hemolysis assay were conducted to assess in vitro antibacterial and cytotoxic activities. Moreover, in vivo wound healing potential was determined by an excision wound model in mice.

RESULTS

RP-HPLC showed significant content of polyphenols and bergenin (6.05 ± 0.12 μg/mg) in B. ciliata R extract. Crude extract possesses higher overall antioxidant and antibacterial capacities than bergenin due to presence of multiple phytoconstituents in extract. Both samples showed low hemolytic activity indicating their safe profile. Furthermore, mice treated with B. ciliata R extract depicted substantial decrease in wound area (99.3%; p < 0.05) as compared to bergenin, which showed 88.8% of wound closure after 12 days of treatment. Additionally, both treatments reduced epithelization duration by 1.6- and 1.4-fold in B. ciliata R extract (12.0 ± 0.6 days) and bergenin (14.2 ± 0.8 days) treated mice, respectively. This was supported by histopathological examination that showed greater epithelization, fibroblast proliferation, collagen synthesis, and revascularization in mice treated with B. ciliata R.

CONCLUSION

Concisely, it is evident that B. ciliata R contains phytoconstituents in addition to bergenin, which potentiated wound healing activity of the extract. Hence, B. ciliata R is good source of compounds for treating wounds.

Editorial: Special Issue on “New Frontiers in Molecular Mechanisms and Therapies in Neurological Diseases”

We launched our Special Issue (SI) at the beginning of 2021, with the hope to bring together current research in the field of neurodegeneration [...]

Suppression of MAPK/NF-kB and activation of Nrf2 signaling by Ajugarin-I in EAE model of multiple sclerosis

Multiple sclerosis (MS) is a debilitating neurodegenerative autoimmune disease of the central nervous system (CNS). The current study aimed to investigate the neuroprotective properties of Ajugarin-I (Aju-I) against the experimental autoimmune encephalomyelitis (EAE) model of MS and explored the underlying mechanism involved. The protective potential of Aju-I was first confirmed against glutamate-induced HT22 cells and hydrogen peroxide (H₂ O₂ )-induced BV2 cells. Next, an EAE model has been established to investigate the mechanisms of MS and identify potential candidates for MS treatment. The behavioral results demonstrated that Aju-I post-immunization treatment markedly reduced the EAE-associated clinical score, motor impairment, and neuropathic pain. Evans blue and fluorescein isothiocyanate extravasation in the brain were markedly reduced by Aju-I. It effectively restored the EAE-associated histopathological changes in the brain and spinal cord. It markedly attenuated EAE-induced inflammation in the CNS by reducing the expression levels of p-38/JNK/NF-κB but increased the expression of IkB-α. It suppressed oxidative stress by increasing the expression of Nrf2 but decreasing the expression of keap-1. It suppressed EAE-induced apoptosis in the CNS by regulating Bax/Bcl-2 and Caspase-3 expression. Taken together, this study suggests that Aju-I treatment exhibits neuroprotective properties in the EAE model of MS via regulation of MAPK/NF-κB, Nrf2/Keap-1, and Bcl2/Bax signaling.

QbD-based fabrication of transferrin-anchored nanocarriers for targeted drug delivery to macrophages and colon cells for mucosal inflammation healing

Colon mucosal inflammation attracts a plethora of immune cells with overexpressed surface receptors. Colon drug targeting can be aided by exploiting overexpressed cell surface receptors which improve drug site retention for an extended period. We developed Tofacitinib citrate (Tofa) loaded transferrin anchored PLGA nanocarriers (Tofa-P/tfr NCs) via the quality by design (QbD) approach for specific binding to the transferrin receptor (TFR-1/CD71) overexpressed on macrophages and colon epithelial cells. Nanocarriers were produced using a modified emulsion-evaporation method with a protein adsorption technique. The QbD-risk assessment method was adopted to screen the variables impacting the quality of nanocarriers, which were then optimized using the 3³ Box-Behnken design of experiment (DOE). The obtained nanocarriers have the desired physicochemical properties, drug entrapment, tfr adsorption, stability, mucoadhesion, and sustained drug release pattern at pH 7.4 (colon pH). In vitro cell-based studies confirmed the cellular biocompatibility and considerable uptake of nanocarriers by colon and macrophage cells; the uptake was diminished by anti-CD71/TFR1 antibodies. Tofa-P/tfr NCs demonstrated good colon targeting potential in the dextran sulfate sodium (DSS) induced ulcerative colitis (UC) model. In vivo therapeutic efficacy against UC was established through restored morphological and histopathological scores, vascular integrity, antioxidant levels, hematological parameters, pro-inflammatory cytokine/marker levels, and microbial indices. Tofa-P/tfr NCs shut down the elevated STAT-1 and TFR-1 levels, demonstrating the enhanced efficacy of the encapsulated drug. Thus, the QbD-driven approach successfully developed Tofa-P/tfr NCs with good potential to mitigate mucosal inflammation by targeting colon and macrophage surface receptors.

Effect of the Reelin-Dab1 signaling pathway on the abnormal metabolism of Aβ protein induced by aluminum

Aluminum (Al) is a common neurotoxic element that can exacerbate intracellular β-amyloid (Aβ) deposition. Reelin is a highly conserved extracellular glycoprotein that is involved in intracellular Aβ deposition. However, the action of Reelin on aluminum-induced Aβ deposition is not fully understood. Here, we investigated the effects of the Reelin-Dab1 signaling pathway on Aβ deposition in aluminum maltol (Al(mal)₃) exposure in rat pheochromocytoma-derived cells (PC12). Our results showed that Al(mal)₃ exposure decreased activity of PC12, increased expression of Aβ₄₂, and decreased expression of Aβ₄₀. Moreover, Al(mal)₃ exposure in PC12 induced Reelin-Dab1 signaling pathway-associated proteins changed, decreased expression of Reelin and Dab1, and increased expression of pdab1. Moreover, the expression of Reelin, Dab1, and Aβ₄₀ was found to be elevated in PC12 exposed to Al(mal)₃ and corticosterone compared to those exposed to Al(mal)₃. Also, the expression of Reelin, Dab1, and Aβ₄₀ was found to be depressed in PC12 exposed to Al(mal)₃ and streptozotocin compared with cells exposed to Al(mal)₃ alone. These results suggested that Al(mal)₃ inhibits the expression of the Reelin-Dab1 signaling pathway, promoting Aβ deposition. Thus, our findings provided important evidence to better understand how the Reelin-Dab1 signaling pathway may be a potential mechanism of Aβ deposition induced by aluminum.

Potential applications of PEGylated green gold nanoparticles in cyclophosphamide-induced cystitis

We investigated the effect of green tea extract PEGylated gold nanoparticles (P-AuNPs) making use of its targeted and sustained drug delivery against cyclophosphamide (CYP)-induced cystitis. AuNPs were synthesized by reduction reaction of gold salts with green tea extract following the concept of green synthesis. Mostly spherical-shaped P-AuNPs were synthesized with an average size of 14.3 ± 3.3 nm. Pre-treatment with P-AuNPs (1, 10 mg/kg, i.p.) before CYP (150 mg/kg, i.p.) challenge suggested its uroprotective properties. P-AuNPs significantly reversed all pain-like behaviours and toxicities produced by CYP resulting in a decreased aspartate aminotransferase, alanine aminotransferase, C-reactive protein, and creatinine level. P-AuNPs increased anti-oxidant system by increasing the level of reduced glutathione, glutathione-S-transferase, catalase and superoxide dismutase, and reduced nitric oxide production in bladder tissue. Additionally, it attenuated hypokalaemia and hyponatremia, along with a decrease in Evans blue content in bladder tissue and peritoneal cavity. CYP-induced bladder tissue damage observed by macroscopic and histological findings were remarkably attenuated by P-AuNPs, along with reduced fibrosis of collagen fibre in bladder smooth muscles shown by Masson's trichrome staining. Additionally, alterations in hematological parameters and clinical scoring were also prevented by P-AuNPs suggesting its uroprotective effect.

Anti-nociceptive effects of magnolol via inhibition of TRPV1/P2Y and TLR4/NF-κB signaling in a postoperative pain model

AIMS

The current study explored the anti-nociceptive activity of magnolol in post-incisional inflammatory nociceptive pain.

MAIN METHODS

Preliminary, the anti-inflammatory, antioxidant, and cytoprotective potential of magnolol were confirmed against hydrogen peroxide (H₂O₂)-induced PC12 cells. Next, an in-vivo model of planter incision surgery was established in BALB/c mice. Tramadol 50 mg/kg intraperitoneal (i.p.) and magnolol (0.1, 1, 10 mg/kg i.p. + 10 mg/kg intra planter) were administered after plantar incision surgery and behavior parameters were measured.

KEY FINDINGS

The results indicate that magnolol significantly suppressed post-incision-induced mechanical allodynia, thermal hyperalgesia, and paw edema. Magnolol promisingly inhibited post-incision induces nitric oxide (NO), malondialdehyde (MDA), eosinophil peroxidase (EPO), and neutrophil infiltration. Magnolol strongly attenuated post-incision inducing the release of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and inhibited deoxyribonucleic acid (DNA) fragmentation. Magnolol markedly reverses post-incisional histopathological changes and biochemical composition of the incised paw. Magnolol markedly down-regulated post-incisional increase expression of transient receptor potential vanilloid 1 (TRPV1), purinergic (P2Y) nociceptors as well as toll-like receptor 4 (TLR4), nuclear factor kappa light chain enhancer of activated B cell (NF-κB), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) while upregulating the expression of inhibitor of nuclear kappa B alpha (IκB-α).

SIGNIFICANCE

The present study strongly suggests that magnolol significantly suppressed post-incisional inflammatory nociceptive pain by targeting TRPV1/P2Y and TLR4/NF-κB signaling.

Synthetic Mono-Carbonyl Curcumin Analogues Attenuate Oxidative Stress in Mouse Models

Alzheimer’s disease is the commonest form of dementia associated with short-term memory loss and impaired cognition and, worldwide, it is a growing health issue. A number of therapeutic strategies have been studied to design and develop an effective anti-Alzheimer drug. Curcumin has a wide spectrum of biological properties. In this regard, the antioxidant potentials of mono-carbonyl curcumin analogues (h1−h5) were investigated using in vitro antioxidant assays and hippocampal-based in vivo mouse models such as light−dark box, hole board, and Y-maze tests. In the in vitro assay, mono-carbonyl curcumin analogues h2 and h3 with methoxy and chloro-substituents, respectively, showed promising 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis-3-ethylbenzothiazo-line-6-sulfonate (ABTS) free radical scavenging activities. In the in vivo studies, scopolamine administration significantly (p < 0.001) induced oxidative stress and memory impairment in mice, in comparison to the normal control group. The pretreatment with mono-carbonyl curcumin analogues, specifically h2 and h3, significantly decreased (123.71 ± 15.23 s (p < 0.001), n = 8; 156.53 ± 14.13 s (p < 0.001), n = 8) the duration of time spent in the light chamber and significantly enhanced (253.95 ± 19.05 s (p < 0.001), n = 8, and 239.57 ± 9.98 s (p < 0.001), n = 8) the time spent in the dark compartment in the light−dark box arena. The numbers of hole pokings were significantly (p < 0.001, n = 8) enhanced in the hole board test and substantially increased the percent spontaneous alternation performance (SAP %) in the Y-maze mouse models in comparison to the stress control group. In the biomarker analysis, the significant reduction in the lipid peroxidation (MDA) level and enhanced catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH) activities in the brain hippocampus reveal their antioxidant and memory enhancing potentials. However, further research is needed to find out the appropriate mechanism of reducing oxidative stress in pathological models.

Ameliorative effect of two structurally divergent hydrazide derivatives against DSS-induced colitis by targeting Nrf2 and NF-κB signaling in mice

The environmental factors and genetic vulnerability trigger the inflammatory bowel diseases (IBDs) such as ulcerative colitis and Crohn's disease. Furthermore, the oxidative stress and inflammatory cytokines have been implicated in the aggravation of the IBDs. The aim of the present study was to investigate the effect of N-(benzylidene)-2-((2-hydroxynaphthalen-1-yl)diazenyl)benzohydrazides (NCHDH and NTHDH) compounds against the DSS-induced colitis in mice. The colitis was induced by 5% dextran sulfate sodium (DSS) dissolved in normal saline for 5 days. The effect of the NCHDH and NTHDH on the behavioral, biochemical, histological, and immunohistological parameters was assessed. The NCHDH and NTHDH treatment improved the behavioral parameters such as food intake, disease activity index, and diarrhea score significantly compared to DSS control. The NCHDH and NTHDH treatments significantly increased the antioxidant enzymes, whereas oxidative stress markers were markedly reduced. Similarly, the NCHDH and NTHDH treatments significantly suppressed the activity of nitric oxide (NO), myeloperoxidase (MPO), and eosinophil peroxidase (EPO). The histological studies showed a significant reduction in inflammation, immune cell infiltration, and fibrosis in the NCHDH- and NTHDH-treated groups. The immunohistochemical results demonstrated that NCHDH and NTHDH treatments markedly increase the expression level of Nrf2, HO-1 (hemeoxygenase-1), TRX (thioredoxin reductase), and IκB compared to the DSS-induced group. In the same way, the NCHDH and NTHDH significantly reduced the NF-κB and COX-2 (cyclooxygenase-2) expression levels. The NCHDH and NTHDH treatment significantly improved the symptoms associated with colitis via inducing antioxidants and attenuating oxidative stress markers.

Bergenin ameliorates cognitive deficits and neuropathological alterations in sodium azide-induced experimental dementia

Background: Bergenin, 4-O-methyl gallic acid glucoside, is a bioactive compound found in the cortex of Mallotus japonicus (L.f.) Müll.Arg. along with many other natural resources including that from Bergenia species. The present study delineates the neuroprotective potential of bergenin through the modulation of PPAR-γ receptors.

Method: Dementia was induced in the Wistar rats by intraperitoneal (i.p.) administration of sodium azide (12.5 mg/kg for the first 5 days followed by 10 mg/kg for the next 9 days). The rats were then exposed to the Morris water maze test to assess the effect on cognitive abilities followed by a series of biochemical and histopathological evaluations.

Results: Sodium azide-treated rats exhibited a severe deterioration of memory as suggested by poor performance in the spatial learning task in addition to the enhancement of brain acetylcholinesterase potential, oxidative stress, inflammation, and amyloid-β (Aβ) accumulation. Administration of bergenin to sodium azide-treated rats significantly recovered cognition and related biochemical variations. Further, co-administration of Bisphenol A diglycidyl ether (BADGE), a PPAR-γ antagonist with bergenin challenged its neuroprotective effects.

Conclusions: The findings of our study exhibit that the cognitive restoration potential of bergenin may be attributed to its modulatory effects against cholinesterase, oxidative stress, and inflammatory markers, as well as its neuroprotective actions, thus aligning it as a possible therapy for Alzheimer’s disease-related dementia. The study also fortifies the significance of PPAR-γ receptors in dementia.

The Neuroprotective Propensity of Organic Extracts of Acacia stenophylla Bark and Their Effectiveness Against Scopolamine-/Diazepam-Induced Amnesia in Mice

Background

Alzheimer's disease (AD) is a neurodegenerative disorder that is more prevalent in the elderly. There is extensive literature on using Acacia species against central nervous system disorders, although Acacia stenophylla has not been investigated for any neuroprotective potential. The purpose of the study was to elucidate the ameliorative effect of ethyl acetate (ASEE) and butanol (ASB) extracts from the bark of A. stenophylla on memory deficits and cognitive dysfunction in scopolamine- or diazepam-induced amnesia in mice.

Methods

The phytochemical constituents of the extracts of A. stenophylla were determined by GC-MS and the in vitro anticholinesterase plus antioxidant activities were also evaluated. Anti-amnesic effects were determined employing the open field test, elevated plus maze (EPM), Morris water maze (MWM), and Y-maze paradigms.

Results

The in vitro cholinesterase assays disclosed a concentration-dependent inhibition of both AChE and BuChE with IC₅₀ values of 28.48 and 44.86 µg/mL for the ASEE extract and 32.04 and 50.26 µg/mL for the ASB extract against AChE and BuChE respectively. DPPH and H₂O₂ antioxidant assays revealed respective IC₅₀ values for the ASEE extract of 28.04 and 59.84 µg/mL, plus 32.77 and 64.65 µg/mL for ASB extract. The findings revealed that both extracts possessed substantial antioxidant properties. Furthermore, these fractions restored scopolamine- and diazepam-induced memory deficits in a dose-dependent manner, as observed by a significant decrease in the transfer latency in EPM, reduction in escape latency, added time spent in the target quadrant in the MWM, and elevated spontaneous alternation behavior (SAB) in the Y-maze test.

Conclusion

The ameliorative effect of A. stenophylla on scopolamine- and diazepam-induced amnesia can be attributed to antioxidant and anticholinesterase activity. Consequently, the use of A. stenophylla might be exploited in the alleviation of oxidative stress and the management of AD.

Coagulansin-A improves spatial memory in 5xFAD Tg mice by targeting Nrf-2/NF-κB and Bcl-2 pathway

The present study was designed to investigate the underlying molecular signaling of Coagulansin-A (Coag-A) as a therapeutic agent against Alzheimer's disease (AD). Preliminarily, it exhibited a neuroprotective effect against H₂O₂-induced oxidative stress in HT-22 cells. The in vivo studies were performed by administering Coag-A (0.1, 1, and 10 mg/kg) intraperitoneally to 5xFAD transgenic (Tg) mouse model. Coag-A (10 mg/kg) significantly attenuated the cognitive decline compared to Tg mice group in the shallow water maze (SWM) and Y-maze test paradigms. The anti-aggregation potential of Coag-A was determined by performing Fourier transform-infrared (FT-IR) spectroscopy and differential scanning calorimeter (DSC) analysis in the prefrontal cortex (PFC) and hippocampal (HC) regions of mice brain. The FT-IR spectra demonstrated the inhibition of amyloid beta (Aβ) through a decrease in β-sheet aggregation, along with the inhibition of changes in the lipids, proteins, and phospholipids. The DSC analysis displayed a low-temperature exotherm associated with the reversible process of aggregation of soluble protein fractions prior to denaturation. Furthermore, Coag-A treatment displayed a regular density of granule cells in H&E stained sections, along with a reduced amyloid load and PAS-positive granules in all the regions of interest in mice brain. The real-time polymerase chain reaction (q-PCR), western blot and immunohistochemical (IHC) analysis demonstrated antioxidant, anti-inflammatory, and anti-apoptotic effect of Coag-A by enhancing the expression of nuclear factor erythroid-2-related factor (Nrf-2) and reducing nuclear factor kappa B (NF-κB) and Bax protein expression. In addition, Coag-A significantly increased the antioxidant enzymes and proteins level, along with a reduced pro-inflammatory cytokines production.

Anti-Inflammatory and Anti-Rheumatic Potential of Selective Plant Compounds by Targeting TLR-4/AP-1 Signaling: A Comprehensive Molecular Docking and Simulation Approaches

Plants are an important source of drug development and numerous plant derived molecules have been used in clinical practice for the ailment of various diseases. The Toll-like receptor-4 (TLR-4) signaling pathway plays a crucial role in inflammation including rheumatoid arthritis. The TLR-4 binds with pro-inflammatory ligands such as lipopolysaccharide (LPS) to induce the downstream signaling mechanism such as nuclear factor κappa B (NF-κB) and mitogen activated protein kinases (MAPKs). This signaling activation leads to the onset of various diseases including inflammation. In the present study, 22 natural compounds were studied against TLR-4/AP-1 signaling, which is implicated in the inflammatory process using a computational approach. These compounds belong to various classes such as methylxanthine, sesquiterpene lactone, alkaloid, flavone glycosides, lignan, phenolic acid, etc. The compounds exhibited different binding affinities with the TLR-4, JNK, NF-κB, and AP-1 protein due to the formation of multiple hydrophilic and hydrophobic interactions. With TLR-4, rutin had the highest binding energy (−10.4 kcal/mol), poncirin had the highest binding energy (−9.4 kcal/mol) with NF-κB and JNK (−9.5 kcal/mol), respectively, and icariin had the highest binding affinity (−9.1 kcal/mol) with the AP-1 protein. The root means square deviation (RMSD), root mean square fraction (RMSF), and radius of gyration (RoG) for 150 ns were calculated using molecular dynamic simulation (MD simulation) based on rutin’s greatest binding energy with TLR-4. The RMSD, RMSF, and RoG were all within acceptable limits in the MD simulation, and the complex remained stable for 150 ns. Furthermore, these compounds were assessed for the potential toxic effect on various organs such as the liver, heart, genotoxicity, and oral maximum toxic dose. Moreover, the blood–brain barrier permeability and intestinal absorption were also predicted using SwissADME software (Lausanne, Switzerland). These compounds exhibited promising physico-chemical as well as drug-likeness properties. Consequently, these selected compounds portray promising anti-inflammatory and drug-likeness properties.

Pharmacological mechanism of xanthoangelol underlying Nrf-2/TRPV1 and anti-apoptotic pathway against scopolamine-induced amnesia in mice

Alzheimer's disease (AD) is a well-known type of age-related dementia. The present study was conducted to investigate the effect of xanthoangelol against memory deficit and neurodegeneration associated with AD. Preliminarily, xanthoangelol produced neuroprotective effect against H₂O₂-induced HT-22 cells. Furthermore, effect of xanthoangelol against scopolamine-induced amnesia in mice was determined by intraperitoneally (i.p.) administering xanthoangelol (1, 10 and 20 mg/kg), 30 min prior to induction. Mice were administered scopolamine at a concentration of 1 mg/kg; i.p. for the induction of amnesia associated with AD. Xanthoangelol dose dependently reduced the symptoms of Alzheimer's disease as observed by the results obtained from the behavioral analysis performed using Morris water maze and Y-maze test. The immunohistochemical analysis suggested that xanthoangelol significantly improved Keap-1/Nrf-2 signaling pathway. It greatly reduced the effects of oxidative stress and showed improvement in the anti-oxidant enzyme such as GSH, GST, SOD and catalase. Additionally, xanthoangelol decreased the expression of transient receptor potential vanilloid 1 (TRPV-1), a nonselective cation channel, involved in synaptic plasticity and memory. It activated the anti-oxidants and attenuated the apoptotic (Bax/Bcl-2) pathway. Xanthoangelol also significantly attenuated the scopolamine-induced neuroinflammation by the inhibition of interleukin-1 beta (IL-1β), and tumor necrosis factor-α (TNF-α) levels. The histological analysis, showed a significant reduction in amyloid plaques by xanthoangelol. Therefore, the present study indicated that xanthoangelol has the ability to ameliorate the AD symptoms by attenuating neuroinflammation and neurodegeneration induced by scopolamine.

Magnolol prevented brain injury through the modulation of Nrf2-dependent oxidative stress and apoptosis in PLP-induced mouse model of multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated chronic inflammatory demyelinating disease of the central nervous system (CNS). The aim of the current study was to investigate the effects of magnolol in an experimental autoimmune encephalomyelitis (EAE) model of MS in female mice. Magnolol (0.1, 1, and 10 mg/kg) was administered once daily for 21 days after immunization of mice. Magnolol post-immunization treatment significantly reversed clinical scoring, EAE-associated pain parameters, and motor dysfunction in a dose-dependent manner. Magnolol treatment significantly inhibited oxidative stress by reducing malondialdehyde (MDA), nitric oxide (NO) production, and myeloperoxidase (MPO) activity while enhancing the level of antioxidants such as reduced glutathione (GSH), glutathione-S-transferase (GST), catalase, and superoxide dismutase (SOD) in the brain and spinal cord. It reduced cytokine levels in the brain and spinal cord. It suppressed CD8+ T cells frequency in the spleen tissue. Magnolol remarkably reversed the EAE-associated histopathology of the brain and spinal cord tissue. Magnolol significantly intensifies the antioxidant defense system by enhancing the expression level of nuclear factor erythroid 2-related factor (Nrf2) while decreasing the expression of inducible nitric oxide synthase (iNOS) and cleaved-caspase-3 in the brain. Molecular docking results showed that magnolol possesses a better binding affinity for Nrf2, iNOS, and caspase-3 proteins. Taken together, the present study demonstrated that magnolol has significant neuroprotective properties in EAE via inhibition of oxidative stress.

Cassia artemisiodes attenuates nociceptive and diabetes-induced neuropathic pain modalities apropos antioxidant and anti-inflammatory mechanisms

Cassia plants have a considerable position in conventional systems of medicine. The possible anti-nociceptive, anti-inflammatory, and anti-neuropathic properties of Cassia artemisiodes (CAD) extract were tested using the standard animal models. In this study, in vitro antioxidant, cyclooxygenase (COX-1 and 2), and 5-lipoxygenase (5-LOX) inhibitory assays were performed. The anti-inflammatory activity was evaluated using carrageenan, histamine, and serotonin-induced paw edema models. Antipyretic activity, thermally and chemically-induced nociception, and naloxone antagonistic activities were carried out. The CAD extract was tested for anti-neuropathic activity in the streptozotocin-induced diabetic neuropathy model. Suppressing the effect of CAD extract on the mRNA level of inducible nitric oxide synthase (iNOS), COX-2, and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) was determined by performing RT-PCR. The CAD extract inhibited COX-2 and 5-LOX enzymes, paw inflammation, and reduced nociceptive behaviors. The mRNA gene expression of iNOS, COX-2, and inflammatory cytokines was reduced significantly with increased DPPH scavenging activity. The extract significantly reduced the diabetes-induced neuropathic pain. In a nutshell, these results recommended that the CAD extract has anti-nociceptive and anti-neuropathic activities due to inhibition of inflammatory and oxidative signaling.

Design and Evaluation of pH-Sensitive Nanoformulation of Bergenin Isolated from Bergenia ciliata

The aim of the current study is extraction and isolation of bergenin from Bergenia ciliata and fabrication of pH-sensitive Eudragit^® L100 (EL100) polymeric nanoparticles (NP) to tackle limitations of solubility. Bergenin-loaded EL100 nanoparticles (BN-NP) were fabricated via nanoprecipitation and an experimental design was conducted for optimization. A reverse phase-high performance liquid chromatography (RP-HPLC) method was developed for the quantitation of bergenin. The optimized nanoformulation was characterized by its particle size, morphology, loading capacity, entrapment efficiency, drug-excipient interaction and crystallinity. An in vitro assay was executed to gauge the release potential of pH-sensitive nanoformulation. The mean particle size, zeta potential and polydispersity index (PDI) of the optimized nanoparticles were observed to be 86.17 ± 2.1 nm, -32.33 ± 5.53 mV and 0.30 ± 0.03, respectively. The morphological analysis confirmed the spherical nature of the nanoparticles. Drug loading capacity and entrapment efficiency were calculated to be 16 ± 0.34% and 84 ± 1.3%, respectively. Fourier transform infrared spectroscopy (FTIR) studies unfolded that no interaction was present between the drug and the excipients in the nanoformulation. Crystallography studies revealed that the crystalline nature of bergenin was changed to amorphous and the nanoformulation was stable for up to 3 months at 40 °C. The present study confirms that bergenin isolation can be scaled up from abundantly growing B. ciliata. Moreover, it could also be delivered by entrapment in stimuli-responsive polymer, preventing the loss of drug in healthy tissues.

The 7-Hydroxyflavone attenuates chemotherapy-induced neuropathic pain by targeting inflammatory pathway

Vincristine and paclitaxel are widely used chemotherapeutic drugs for the treatment of brain tumors, breast cancer, leukemia, lymphomas, and malignant solid tumors. Though, these drugs are associated with some severe adverse effects including peripheral neuropathic pain. The anti-nociceptive and anti-inflammatory properties of the 7-Hydroxyflavone (7HF) were evaluated in the mice using thermally- and chemically-induced nociception, naloxone antagonistic test, and carrageenan-induced paw edema models. Initially, the in-vitro cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibitory assays were carried out. Peripheral neuropathic pain was induced in the Sprague Dawley (SD) rats by administration of paclitaxel (4 mg/kg) and vincristine (200 µg/kg) on days 1, 3, 5, 7, and 9, respectively. The protective effect of 7HF was assessed against the chemotherapy-induced peripheral neuropathy in the rats. Moreover, the expression of the inflammatory mediators in the spinal cord was investigated through RT-PCR. In addition, a computational study was performed to find the potential therapeutic targets and the binding mechanism of 7HF. The 7HF caused concentration-dependent inhibition of COX-2 and 5-LOX, it attenuated the nociceptive pain, carrageenan-induced paw edema, and the development of mechanical and cold allodynia, and hyperalgesia dose-dependently without causing motor coordination deficit. Likewise, the 7HF decreased the vincristine-induced increased expression of different inflammatory mediators including COX-2, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and nuclear factor-kappa B (NF-κB). The computational study showed the effective interactions of 7HF with the binding sites of NF-κB, COX-2, and 5-LOX, exert its inhibitory activities. These findings reveal that the 7HF has anti-nociceptive, anti-inflammatory, and anti-neuropathic potentials.

Icariin attenuates cyclophosphamide-induced cystitis via down-regulation of NF-кB and up-regulation of Nrf-2/HO-1 signaling pathways in mice model

Cystitis is a chronic bladder pain associated with frequency and nocturia. In the present study, Icariin a prenylated flavonoid extracted from Epimedium koreanum, was investigated against cyclophosphamide (CYP)-induced cystitis pain in mice model. Preliminarily in an acute model, single dose of CYP (150 mg/kg; i.p) was administered followed by Icariin (5, 25 and 50 mg/kg, i.p.). The visceral sensitivity and nociceptive behaviors were significantly ameliorated by pretreatment with Icariin (25, 50 mg/kg) that were assessed by spontaneous pain scoring, von Frey test and clinical scoring. Further, in chronic model Icariin (25 mg/kg, i.p.) was administered for 10 consecutive days prior to CYP (75 mg/kg; i.p) challenged every 3rd day for the duration of 10 days. Icariin not only had a protective effect on edema including bladder wet weight and hemorrhage but also had a potential to reduce vascular permeability, mast cells infiltration and tissue fibrosis. Evidently, Icariin prevented the neutrophilia/lymphopenia caused by CYP, and markedly improved the antioxidant enzymes level including superoxide dismutase, glutathione sulfo-transferase, catalase, glutathione level and reduced Malondialdehyde level, myeloperoxidase activity and nitric oxide, and also decreased the production of tumor necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β) in bladder. Icariin markedly enhanced the Nrf-2, heme oxygenase (HO-1) and IкB-α expression, while attenuated the expression level of Keap1, TLR-4, NF-кB, i-NOS, COX-2 and TRPV1 as compared to negative group. This research illustrated the anti-inflammatory properties of Icariin and effectively improved CYP-induced cystitis pain.

Comprehensive in vivo and in silico approaches to explore the hepatoprotective activity of poncirin against paracetamol toxicity

In the present study, poncirin was evaluated against paracetamol-induced liver injury using in vivo and computational approaches. Paracetamol was administered intraperitoneally (i.p,) to establish liver injury in mice and, subsequently, to investigate the hepatoprotective effect of poncirin (administered intraperitoneally) on liver injury. The effect of poncirin was evaluated against the liver injury markers and inflammatory cytokines. Similarly, in the present study, the antioxidants and oxidative stress parameters were also assessed following paracetamol-induced liver injury. The histological studies following liver injury were also assessed using H and E staining, Masson's trichrome staining, and periodic acid-Schiff staining. Similarly, the computational approach was used to assess the pharmacokinetic parameters of poncirin and its interaction with various protein targets. Poncirin markedly improved the antioxidant enzymes while attenuated the oxidative stress markers and inflammatory cytokines. Poncirin also markedly improved hematological parameters. Furthermore, poncirin treatment significantly improved the histological parameters using H and E staining, Masson's trichrome, and PAS staining compared to the control. Poncirin treatment also improved the liver function tests and liver synthetic activity compared to paracetamol treated group. The immunohistochemistry analysis revealed significant decrease in the inflammatory signaling protein such as nuclear factor kappa light chain enhancer of activated B cells (NF-κB), Jun N-terminal kinase (JNK), and cyclooxygenase-2 (COX-2) expression level compared to the paracetamol treated group. Computational analysis (molecular docking and molecular dynamic simulation) showed significant binding affinity of poncirin with the NF-κB, JNK, COX-2, IL-1β, IL-6, and TNF-α via multiple hydrophilic and hydrophobic binds. Similarly, the SwissADME software revealed that poncirin follows various drug-likeness rules and exhibited better pharmacokinetic parameters. Poncirin improved the sign and symptoms associated with liver injury using both in vivo and computational approaches.

Neuroprotective Potential of Synthetic Mono-Carbonyl Curcumin Analogs Assessed by Molecular Docking Studies

Cognitive decline in dementia is associated with deficiency of the cholinergic system. In this study, five mono-carbonyl curcumin analogs were synthesized, and on the basis of their promising in vitro anticholinesterase activities, they were further investigated for in vivo neuroprotective and memory enhancing effects in scopolamine-induced amnesia using elevated plus maze (EPM) and novel object recognition (NOR) behavioral mice models. The effects of the synthesized compounds on the cholinergic system involvement in the brain hippocampus and their binding mode in the active site of cholinesterases were also determined. Compound h2 (p < 0.001) and h3 (p < 0.001) significantly inhibited the cholinesterases and reversed the effects of scopolamine by significantly reducing TLT (p < 0.001) in EPM, while (p < 0.001) increased the time exploring the novel object. The % discrimination index (DI) was significantly increased (p < 0.001) in the novel object recognition test. The mechanism of cholinesterase inhibition was further validated through molecular docking study using MOE software. The results obtained from the in vitro, in vivo and ex vivo studies showed that the synthesized curcumin analogs exhibited significantly higher memory-enhancing potential, and h3 could be an effective neuroprotective agent. However, more study is suggested to explore its exact mechanism of action.

Withametelin, a novel phytosterol, alleviates neurological symptoms in EAE mouse model of multiple sclerosis via modulation of Nrf2/HO-1 and TLR4/NF-κB signaling

Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system (CNS) that remains incurable. Withametelin (WMT), a phytosterol, showed diverse biological activities isolated from the leaves of Datura innoxa. In the present study, we used an in vitro model of HT22 and BV-2 cell lines and an in vivo murine model of MS, experimental autoimmune encephalomyelitis (EAE), to explore the antioxidant and anti neuroinflammatory potential of WMT. The results showed that pretreatment with WMT markedly inhibited H₂O₂-induced cytotoxicity and oxidative stress in a dose-dependent manner. Correspondingly, WMT post-immunization treatment significantly attenuated EAE-induced clinical score, weight loss, neuropathic pain behaviors, and motor dysfunction. It markedly lowers EAE-induced elevated circulating leucocytes, spinal deformity, and splenomegaly. It strikingly inhibited the Evans blue and FITC extravasation in the brain. It remarkably reversed the EAE-induced histopathological alteration of the brain, spinal cord, eye, and optic nerve. It significantly intensified the antioxidant defense mechanism by improving the expression level of nuclear factor-erythroid-related factor-2 (Nrf2), heme-oxygenase-1 (HO-1) but reducing the expression level of the Kelch-like-ECH-associated-protein-1 (keap-1), inducible-nitric-oxide-synthase (iNOS) in the CNS. Likewise, it markedly suppressed neuroinflammation by reducing the expression level of toll-like-receptor 4 (TLR4), nuclear-factor-kappa-B (NF-κB), activator-protein-1 (AP-1) but increased the expression level IkB-α in the CNS. Furthermore, molecular dynamics simulations and MMPBSA binding free energies were determined to validate the dynamic stability of complexes and shed light on the atomic level intermolecular interaction energies. Taken together, this study showed that WMT has significant neuroprotective potential in EAE via modulation of Nrf2 mediated-oxidative stress and NF-κB mediated inflammation.

Duration of Social Isolation Affects Production of Nitric Oxide in the Rat Brain

Social isolation deprives rodents of social interactions that are critical for normal development of brain and behavior. Several studies have indicated that postweaning isolation rearing may affect nitric oxide (NO) production. The aim of this study was to compare selected behavioral and biochemical changes related to NO production in the brain of rats reared in social isolation for different duration. At the age of 21 days, male Sprague Dawley rats were randomly assigned into four groups reared in isolation or socially for 10 or 29 weeks. At the end of the rearing, open-field and prepulse inhibition (PPI) tests were carried out. Furthermore, in several brain areas we assessed NO synthase (NOS) activity, protein expression of nNOS and iNOS isoforms and the concentration of conjugated dienes (CD), a marker of oxidative damage and lipid peroxidation. Social isolation for 10 weeks resulted in a significant decrease in PPI, which was accompanied by a decrease in NOS activity in the cerebral cortex and the cerebellum, an increase in iNOS in the hippocampus and an increase in CD concentration in cortex homogenate. On the other hand, a 29 week isolation had an opposite effect on NOS activity, which increased in the cerebral cortex and the cerebellum in animals reared in social isolation, accompanied by a decrease in CD concentration. The decrease in NOS activity after 10 weeks of isolation might have been caused by chronic stress induced by social isolation, which has been documented in previous studies. The increased oxidative state might result in the depleted NO bioavailability, as NO reacts with superoxide radical creating peroxynitrite. After 29 weeks of isolation, this loss of NO might be compensated by the subsequent increase in NOS activity.

Cyclopentanone Derivative Attenuates Memory Impairment by Inhibiting Amyloid Plaques Formation in the 5xFAD Mice

Alzheimer's disease (AD) is a chronic neurodegenerative disorder. This study was designed to investigate the effects of cyclopentanone derivative i.e., 2-(hydroxyl-(3-nitrophenyl)methyl)cyclopentanone (3NCP) on behavior, amyloid β (Aβ) plaque deposition, and βAPP cleaving enzyme-1 (BACE-1) expression in the 5xFAD mouse brain. In this study, computational studies were conducted to predict the binding mode of the 3NCP with target sites of the β-secretase. In vivo studies were performed on the 5xFAD mice model of AD using different behavioral test models like light/dark box, elevated plus maze (EPM), and the Barnes maze tests for the assessment of anxiety, spatial learning and memory. The thioflavin-S staining, immunohistochemistry (IHC), and RT-PCR studies were carried out to find the effect of the 3NCP on the β-amyloid plaques formation and BACE-1 expression. The results of the computational studies showed that the 3NCP has excellent binding affinities for beta-secretase. The light/dark box study depicted that the 3NCP does not cause anxiety. The 3NCP treatment effects in the EPM and Barnes maze tests showed a significant effect on learning and memory. Furthermore, the results of the thioflavin staining and IHC revealed that the 3NCP significantly reduced the formation of the beta-amyloid plaques in brain tissues. Moreover, the RT-PCR study showed that 3NCP significantly reduced the BACE-1 expression in the brain. Conclusively, the results of the current study demonstrate that the 3NCP may be a potential candidate for AD treatment in the future.