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Khumalo GP, Loa-Kum-Cheung W, Van Wyk BE, Feng Y, Cock IE. Leaf extracts of eight selected southern African medicinal plants modulate pro-inflammatory cytokine secretion in LPS-stimulated RAW 264.7 macrophages. Inflammopharmacology 2024; 32:1607-1620. [PMID: 38310564 PMCID: PMC11006729 DOI: 10.1007/s10787-023-01420-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 12/22/2023] [Indexed: 02/06/2024]
Abstract
This study investigates the anti-inflammatory properties of extracts prepared from the leaves of eight southern African medicinal plants used traditionally to treat inflammation and pain. The inhibitory effect of aqueous and ethanol extracts on the release of pro-inflammatory cytokines was determined in lipopolysaccharide (LPS) stimulated and unstimulated RAW 264.7 murine macrophage cells. The levels of interleukin (IL)-1β, IL-6, tumour necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein (MIP)-2 release were determined using cytokine multiplex-bead assays. The ethanol extracts of Melianthus comosus Vahl (commonly known as honey flower), Tetradenia riparia (Hochst.) Codd (misty plume bush) and Warburgia salutaris (G. Bertol.) Chiov. (pepper-bark tree), demonstrated the most significant inhibitory activity, with over 50-fold inhibition of IL-1β, IL-6 and TNF-α levels in LPS-stimulated RAW 264.7 macrophages. The aqueous extract of M. comosus also significantly inhibited the secretion of all the tested cytokines and chemokines. Phytochemical investigation of M. comosus ethanol leaf extract using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) led to the detection of crassolide, deoxylimonoic acid D-ring-lactone, 2-hydroxynonanoic acid and 5-noniloxytryptamine. To the best of our knowledge, the cytokine inhibition properties of most of the medicinal plants screened in this study are reported for the first time. Our results support the use of southern African medicinal plants as anti-inflammatory remedies and provide an insight into the immunomodulatory mechanisms of action.
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Affiliation(s)
- Gugulethu P Khumalo
- Centre for Planetary Health and Food Security, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, QLD, 4111, Australia
- School of Environment and Science, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, QLD, 4111, Australia
| | - Wendy Loa-Kum-Cheung
- Griffith Institute for Drug Discovery, Griffith University, 46 Don Young Rd, Nathan, QLD, 4111, Australia
| | - Ben-Erik Van Wyk
- Department of Botany and Plant Biotechnology, University of Johannesburg, Auckland Park, P.O. Box 524, Johannesburg, 2006, South Africa
| | - Yunjiang Feng
- School of Environment and Science, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, QLD, 4111, Australia
- Griffith Institute for Drug Discovery, Griffith University, 46 Don Young Rd, Nathan, QLD, 4111, Australia
| | - Ian E Cock
- Centre for Planetary Health and Food Security, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, QLD, 4111, Australia.
- School of Environment and Science, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, QLD, 4111, Australia.
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Shi Y, Tian T, Cai EL, Yang C, Yang X. miR-214 Alleviates Ischemic Stroke-Induced Neuronal Death by Targeting DAPK1 in Mice. Front Neurosci 2021; 15:649982. [PMID: 33841091 PMCID: PMC8032895 DOI: 10.3389/fnins.2021.649982] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/01/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Ischemic stroke induces neuronal cell death and causes brain dysfunction. Preventing neuronal cell death after stroke is key to protecting the brain from stroke damage. Nevertheless, preventative measures and treatment strategies for stroke damage are scarce. Emerging evidence suggests that microRNAs (miRNAs) play critical roles in the pathogenesis of central nervous system (CNS) disorders and may serve as potential therapeutic targets. METHODS A photochemically induced thrombosis (PIT) mouse model was used as an ischemic stroke model. qRT-PCR was employed to assess changes in miRNAs in ischemic lesions of PIT-stroke mice and primary cultured neurons subjected to oxygen-glucose deprivation (OGD). 2,3,5-triphenyltetrazolium chloride (TTC) staining was performed to evaluate brain infarction tissues in vivo. TUNEL staining was employed to assess neuronal death in vitro. Neurological scores and motor coordination were investigated to evaluate stroke damage, including neurological deficits and motor function. RESULTS In vivo and in vitro results demonstrated that levels of miR-124 were significantly decreased following stroke, whereas changes in death-associated protein kinase 1 (DAPK1) levels exhibited the converse pattern. DAPK1 was identified as a direct target of miR-124. N-methyl-D-aspartate (NMDA) and OGD-induced neuronal death was rescued by miR-124 overexpression. Upregulation of miR-124 levels significantly improved PIT-stroke damage, including the overall neurological function in mice. CONCLUSION We demonstrate the involvement of the miR-124/DAPK1 pathway in ischemic neuronal death. Our results highlight the therapeutic potential of targeting this pathway for ischemic stroke.
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Affiliation(s)
- Yan Shi
- Faculty of Laboratory Medicine, School of Medicine, Hunan Normal University, Changsha, China
| | - Tian Tian
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Guangdong Key Lab of Brain Connectomics, Shenzhen, China
| | - Er-Li Cai
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
| | - Can Yang
- Department of Emergency Surgery, Hubei Provincial Hospital of Integrated Chinese and Western Medicine, Wuhan, China
| | - Xin Yang
- The Brain Cognition and Brain Disease Institute, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Guangdong Key Lab of Brain Connectomics, Shenzhen, China
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