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Zhang C, Zhou J, Zhuo L, Zhang W, Lv L, Zhu L, Zhang J, Feng F, Liu W, Han L, Liao W. The TLR4/NF-κB/NLRP3 and Nrf2/HO-1 pathways mediate the neuroprotective effects of alkaloids extracted from Uncaria rhynchophylla in Parkinson's disease. JOURNAL OF ETHNOPHARMACOLOGY 2024:118391. [PMID: 38797377 DOI: 10.1016/j.jep.2024.118391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 05/18/2024] [Accepted: 05/24/2024] [Indexed: 05/29/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Parkinson's disease (PD) is the second most common neurodegenerative disorder with limited therapeutic options available. Neuroinflammation plays an important role in the occurrence and development of PD. Alkaloids extracted from Uncaria rhynchophylla (URA), have emerged as a potential neuroprotective agent because of its anti-inflammatory and anti-oxidant properties. Nevertheless, the underlying mechanism by which URA exerts neuroprotective effects in PD remains obscure. AIM OF THE STUDY The main aim of this study was to investigate the neuroprotective effects and underlying mechanism of URA in the treatment of PD through in vivo and in vitro models, focusing on the neuroinflammation and oxidative stress pathways. MATERIALS AND METHODS The protective effects of URA against PD were evaluated by neurobehavioral tests, immunohistochemistry, serum biochemical assays, and real-time quantitative polymerase chain reaction in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice. The role of the TLR4/NF-κB/NLRP3 pathway and the Nrf2/HO-1 pathway in URA-mediated effects was examined in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and a microglia-neuron coculture system. RESULTS URA significantly alleviated motor deficits and dopaminergic neurotoxicity, and reversed the abnormal secretion of inflammatory and oxidative stress factors in the serum of MPTP-induced mice. URA suppressed the gene expression of Toll-like receptor 4 (TLR4), NOD-like receptor protein 3, and cyclooxygenase 2 (COX2) in the striatum of PD mice. Further studies indicated that URA inhibited activation of the TLR4/NF-κB/NLRP3 pathway and enhanced activation of the Nrf2/HO-1 pathway, reduced reactive oxygen species (ROS) production, and reversed the secretion of inflammatory mediators in LPS-stimulated BV-2 microglial cells, thereby alleviating neuroinflammatory damage to SH-SY5Y neuronal cells. CONCLUSION URA exerted neuroprotective effects against PD mainly by the inhibition of the TLR4/NF-κB/NLRP3 pathway and activation of the Nrf2/HO-1 antioxidant pathway, highlighting URA as a promising candidate for PD treatment.
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Affiliation(s)
- Chunxia Zhang
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
| | - Jiayu Zhou
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
| | - Lingxin Zhuo
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
| | - Wenxin Zhang
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
| | - Lingrui Lv
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
| | - Lingmeng Zhu
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
| | - Jiayi Zhang
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
| | - Feng Feng
- Nanjing Medical University, Nanjing 211166, China
| | - Wenyuan Liu
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Zhejiang Center for safety study of drug substances (Industrial Technology Innovation Platform), Hangzhou, 310018, China
| | - Lingfei Han
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China.
| | - Wenting Liao
- Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China.
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Greuel BK, Da Silva DE, Robert-Gostlin VN, Klegeris A. Natural Compounds Oridonin and Shikonin Exhibit Potentially Beneficial Regulatory Effects on Select Functions of Microglia. Brain Sci 2024; 14:328. [PMID: 38671980 PMCID: PMC11048017 DOI: 10.3390/brainsci14040328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 03/22/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Accumulating evidence indicates that the adverse neuroimmune activation of microglia, brain immunocytes that support neurons, contributes to a range of neuroinflammatory disorders, including Alzheimer's disease. Correcting the abnormal functions of microglia is a potential therapeutic strategy for these diseases. Nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor (NLRP) 3 inflammasomes are implicated in adverse microglial activation and their inhibitors, such as the natural compounds oridonin and shikonin, reduce microglial immune responses. We hypothesized that some of the beneficial effects of oridonin and shikonin on microglia are independent of their suppression of NLRP3 inflammasomes. Murine and human microglia-like cells were stimulated with bacterial lipopolysaccharide (LPS) only, which did not induce NLRP3 inflammasome activation or the resulting secretion of interleukin (IL)-1β, allowing for the identification of other anti-inflammatory effects. Under these experimental conditions, both oridonin and shikonin reduced nitric oxide (NO) secretion and the cytotoxicity of BV-2 murine microglia towards HT-22 murine neuronal cells, but upregulated BV-2 cell phagocytic activity. Only oridonin inhibited the secretion of tumor necrosis factor (TNF) by stimulated BV-2 microglia, while only shikonin suppressed the respiratory burst response of human HL-60 microglia-like cells. This observed discrepancy indicates that these natural compounds may have different molecular targets in microglia. Overall, our results suggest that oridonin and shikonin should be further investigated as pharmacological agents capable of correcting dysfunctional microglia, supporting their potential use in neuroinflammatory disorders.
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Affiliation(s)
| | | | | | - Andis Klegeris
- Laboratory of Cellular and Molecular Pharmacology, Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada (V.N.R.-G.)
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Iwuanyanwu VU, Banjo OW, Babalola KT, Olajide OA. Neuroprotection by Alstonia boonei De Wild., Anacardium occidentale L., Azadirachta indica A.Juss. and Mangifera indica L. JOURNAL OF ETHNOPHARMACOLOGY 2023; 310:116390. [PMID: 36965546 DOI: 10.1016/j.jep.2023.116390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/07/2023] [Accepted: 03/10/2023] [Indexed: 06/18/2023]
Abstract
ETHNOPHARMACOLOGY RELEVANCE Alstonia boonei De Wild. (stem bark), Anacardium occidentale L. (stem bark), Azadirachta indica A.Juss (leaves), Enantia chlorantha Oliv. (stem bark), Khaya senegalensis A.Juss (stem bark) Mangifera indica L. (stem bark), and Nauclea latifolia Sm. (stem bark) are used for treating malaria in southwest Nigeria. Surveys revealed that these plants are also employed for treating symptoms of malaria and cerebral malaria in the region. AIM OF THE STUDY In this study, the effects of freeze-dried extracts of these plants were investigated on synthetic hemozoin (HZ)-induced neuroinflammation, neuronal damage, and increased permeability of brain microvascular endothelial cells. MATERIALS AND METHODS Effects of freeze-dried plant extracts were investigated on neuroinflammation by measuring levels of pro-inflammatory mediators in culture supernatants, while in-cell western assays were used to measure protein levels of iNOS and NLRP3. Effects on HZ-induced neurotoxicity and ROS generation was measured using MTT and DCFDA assays, respectively. HZ-induced permeability of hCMEC/D3 endothelial cells was determined using the in vitro vascular permeability assay kit. RESULTS The extracts produced significant (p < 0.05) reduction in TNFα, IL-6, IL-1β, MCP-1, RANTES and iNOS/NO production in HZ-stimulated BV-2 microglia. Pre-treatment with 50 μg/mL of A. boonei, A. indica, A. occidentale, E. chlorantha and M. indica also resulted in the inhibition of NF-κB activation. Pre-treatment with A. indica produced, A. occidentale, M. indica and A. boonei reduced HZ-induced increased NLRP3 protein expression. HZ-induced increased caspase-1 activity was also reduced by A. boonei, A. occidentale, A. indica, E. chlorantha, and M. indica. Freeze-dried extracts of A. boonei, A. occidentale, A. indica and M. indica produced neuroprotective effect in HT-22 neuronal cells incubated with HZ by preventing HZ-induced neurotoxicity, ROS generation, DNA fragmentation and caspase 3/7 activity. Inhibition of HZ-induced increase in permeability of human hCMEC/D3 brain endothelial cells was also observed with A. boonei, A. occidentale, A. indica and M. indica, while reducing the release of TNFα and MMP-9. CONCLUSIONS These results suggest that A. boonei, A. occidentale, A. indica and M. indica are neuroprotective through inhibition of neuroinflammation, neuronal damage and increased permeability of blood brain barrier. The outcome of the study provides pharmacological evidence for the potential benefits of plants as herbal treatments for cerebral malaria symptoms.
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Affiliation(s)
- Victoria U Iwuanyanwu
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, United Kingdom.
| | - Owolabi W Banjo
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, United Kingdom.
| | - Kabirat T Babalola
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, United Kingdom.
| | - Olumayokun A Olajide
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, United Kingdom.
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Neuroprotection by Skimmianine in Lipopolysaccharide-Activated BV-2 Microglia. Molecules 2023; 28:molecules28031317. [PMID: 36770987 PMCID: PMC9920223 DOI: 10.3390/molecules28031317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/18/2023] [Accepted: 01/23/2023] [Indexed: 02/03/2023] Open
Abstract
Skimmianine is a furoquinoline alkaloid which is found in the Zanthoxylum genus and also in other plants of the Rutaceae family. This study evaluated the effects of skimmianine on the production of pro-inflammatory mediators in LPS-activated BV-2 microglia. Cultured BV-2 cells were treated with skimmianine (10, 20 and 30 μM), followed by stimulation with LPS (100 ng/mL). Levels of TNFα and IL-6 in cell supernatants were measured using ELISA, while NO and PGE2 levels were evaluated with Griess assay and EIA, respectively. Western blotting was used to determine the protein expression of iNOS, COX-2, phospho-p65 and phospho-IκBα. Results showed that Skimmianine reduced LPS-induced elevated the secretion of TNFα, IL-6, NO, and PGE2, as well as the increased protein expression of iNOS and COX-2. Experiments to elucidate the mechanisms of the anti-neuroinflammatory activity of skimmianine revealed the significant inhibition of LPS-induced increased NF-κB-mediated luciferase activity. Pre-treatment with skimmianine also reduced LPS-induced the increased phosphorylation of NF-κB/p65 and IκBα proteins. Furthermore, skimmianine interfered with the binding capacity of NF-κB to consensus sites. Skimmianine pre-treatment protected HT-22 cells from toxicity induced by microglia-conditioned media, as well as increasing MAP-2 expression. The results of this study suggest that skimmianine inhibits neuroinflammation in LPS-activated microglia by targeting the NF-κB activation pathway. Skimmianine also produced neuroprotection against neurotoxicity induced by microglia-conditioned media.
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Li B, Wang M, Chen S, Li M, Zeng J, Wu S, Tu Y, Li Y, Zhang R, Huang F, Tong X. Baicalin Mitigates the Neuroinflammation through the TLR4/MyD88/NF- κB and MAPK Pathways in LPS-Stimulated BV-2 Microglia. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3263446. [PMID: 36408278 PMCID: PMC9668451 DOI: 10.1155/2022/3263446] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/22/2022] [Indexed: 09/25/2023]
Abstract
Baicalin (BA) is a major flavone from Scutellaria baicalensis Georgi and has showed significant curative effects in Parkinson's and Alzheimer's diseases. In the present study, we investigated the effects of BA on antineuroinflammation and related signaling cascade in lipopolysaccharide- (LPS-) induced BV-2 microglial model. The results showed that BA significantly attenuated inflammatory mediators (NO, iNOS, IL-1β, COX-2, and PGE2) and suppressed the expression of miR-155. More crucially, BA could regulate the expression of related proteins in Toll-like receptor 4 (TLR4)/myeloid differentiation protein 88 (MyD88)/nuclear factor κB (NF-κB) pathway and suppress the phosphorylation of mitogen-activated protein kinase (MAPK) family. In addition, molecular docking analysis indicated that BA binds to the amino acids Lie 63 and Tyr 65 of TLR4 by π-σ and π-π T-shaped interaction. Thus, BA suppressed the LPS-stimulated neuroinflammation in BV-2 microglia by blocking the TLR4-mediated signal transduction through TLR4/MyD88/NF-κB and MAPK pathways and inhibiting the miR-155 expression. Our findings demonstrated that BA could be a valuable therapeutic for the treatment of neuroinflammation and neurodegenerative diseases.
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Affiliation(s)
- Baojing Li
- The First Affiliated Hospital of Yunnan University of Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
- Yunnan Key Laboratory of Southern Medicinal Utilization, College of Traditional Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
| | - Mingming Wang
- Yunnan Key Laboratory of Southern Medicinal Utilization, College of Traditional Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Shuai Chen
- Yunnan Key Laboratory of Southern Medicinal Utilization, College of Traditional Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
| | - Manping Li
- College of Pharmacy, Jinan University, Guangzhou, China
| | - Jing Zeng
- College of Pharmacy, Jinan University, Guangzhou, China
| | - Saichun Wu
- College of Pharmacy, Jinan University, Guangzhou, China
| | - Yuanqing Tu
- College of Pharmacy, Jinan University, Guangzhou, China
| | - Yanping Li
- Yunnan Key Laboratory of Southern Medicinal Utilization, College of Traditional Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
| | - Rongping Zhang
- Yunnan Key Laboratory of Southern Medicinal Utilization, College of Traditional Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
| | - Feng Huang
- The First Affiliated Hospital of Yunnan University of Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
- Yunnan Key Laboratory of Southern Medicinal Utilization, College of Traditional Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
| | - Xiaoyun Tong
- The First Affiliated Hospital of Yunnan University of Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
- Yunnan Key Laboratory of Southern Medicinal Utilization, College of Traditional Chinese Medicine, Yunnan University of Chinese Medicine, Kunming, China
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Zanthoxylum zanthoxyloides Alkaloidal Extract Improves CCl 4-Induced Hepatocellular Carcinoma-Like Phenotypes in Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:3804379. [PMID: 34367300 PMCID: PMC8337135 DOI: 10.1155/2021/3804379] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/02/2021] [Accepted: 07/13/2021] [Indexed: 02/07/2023]
Abstract
Background Despite the enrollment of new small molecules such as Sorafenib for the treatment of hepatocellular carcinoma (HCC), HCC still remains a significant contributor to cancer-related mortality and morbidity globally. Zanthoxylum zanthoxyloides is long suspected of possessing anticancer bioactive compounds that may hold the prospect of adjunctive therapy against inflammation-related cancers such as HCC. Objective This study assessed the effects of an alkaloidal extract of the leaves of Zanthoxylum zanthoxyloides on CCl4/olive oil (1 : 1 v/v)-induced HCC-like phenotypes in rats. Materials and Methods Zanthoxylum zanthoxyloides alkaloidal extract (ZZAE) was prepared using Soxhlet and liquid-liquid extraction methods. Subsequently, ZZAE was characterized phytochemically. In the curative method, experimental HCC was established in adult (8-10 weeks old) male Sprague-Dawley rats weighing 150-300 g by twice-daily administration of CCl4/olive oil (1 : 1 v/v) (2 mL/kg ip). After confirmation of experimental HCC in rats, the rats were randomly reassigned into seven (7) groups of seven (7) rats each and treated daily for 12 weeks as follows: control (normal saline, 5 ml/kg po), model (CCl4, 5 ml/kg, ip), ZZAE (50, 100, and 200 mg/kg po), carvedilol (6.25 mg/kg po), and 20% Tween20 (1 mL/rat, po). To assess whether ZZAE has a prophylactic (preventive) effect, rats were first treated with ZZAE and later exposed to CCl4 reconstituted in olive oil. Results ZZAE (100 and 200 mg/kg) and carvedilol decreased tumor incidence compared to that of control. Compared to control, ZZAE (100 and 200 mg/kg) significantly (P < 0.05) improved serum GGT. Compared to control, ZZAE improved hepatohistological distortions induced by CCl4/olive oil and also improved liver/body weight ratio. Compared to water, ZZAE arrested mitosis in the Allium cepa assay. Conclusion ZZAE ameliorated CCl4/olive oil-induced HCC-like phenotype in rats and demonstrated general hepatoprotective effects by improving liver and kidney function markers. This finding rationalizes the need for further studies on ZZAE as a potential source of bioactive anti-HCC compounds.
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Welcome MO, Mastorakis NE. The taste of neuroinflammation: Molecular mechanisms linking taste sensing to neuroinflammatory responses. Pharmacol Res 2021; 167:105557. [PMID: 33737243 DOI: 10.1016/j.phrs.2021.105557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 02/07/2023]
Abstract
Evidence indicates a critical role of neuroinflammatory response as an underlying pathophysiological process in several central nervous system disorders, including neurodegenerative diseases. However, the molecular mechanisms that trigger neuroinflammatory processes are not fully known. The discovery of bitter taste receptors in regions other than the oral cavity substantially increased research interests on their functional roles in extra-oral tissues. It is now widely accepted that bitter taste receptors, for instance, in the respiratory, intestinal, reproductive and urinary tracts, are crucial not only for sensing poisonous substances, but also, act as immune sentinels, mobilizing defense mechanisms against pathogenic aggression. The relatively recent discovery of bitter taste receptors in the brain has intensified research investigation on the functional implication of cerebral bitter taste receptor expression. Very recent data suggest that responses of bitter taste receptors to neurotoxins and microbial molecules, under normal condition, are necessary to prevent neuroinflammatory reactions. Furthermore, emerging data have revealed that downregulation of key components of the taste receptor signaling cascade leads to increased oxidative stress and inflammasome signaling in neurons that ultimately culminate in neuroinflammation. Nevertheless, the mechanisms that link taste receptor mediated surveillance of the extracellular milieu to neuroinflammatory responses are not completely understood. This review integrates new data on the molecular mechanisms that link bitter taste receptor sensing to neuroinflammatory responses. The role of bitter taste receptor-mediated sensing of toxigenic substances in brain disorders is also discussed. The therapeutic significance of targeting these receptors for potential treatment of neurodegenerative diseases is also highlighted.
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Affiliation(s)
- Menizibeya O Welcome
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, Abuja, Nigeria.
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