Anti-inflammatory activity of the extracts from Rodgersia podophylla leaves through activation of Nrf2/HO-1 pathway, and inhibition of NF-κB and MAPKs pathway in mouse macrophage cells

Jatrophane and ingenane diterpenoids with anti-inflammatory activity from Euphorbia esula

A phytochemical investigation into the plants of Euphorbia esula L. has yielded 19 diterpenoids, comprising 17 jatrophane-type (1-7 and 9-18) and two ingenane-type (8 and 19). The structures of these compounds were elucidated by a combination of spectrum elucidations, quantum chemical calculations, and X-ray single crystal diffraction. Biological evaluations demonstrated that compounds 6, 8, 18, and 19 show significant anti-inflammatory activity with IC50 values within 10 μM, without displaying any morphological signs of cytotoxicity. Further biological analysis revealed that euphoresulin A (8) is involved in the suppression of inflammatory response by blocking the activation of NF-κB/MAPK and activating Nrf2/HO-1 singling pathways.

Talaromyketides A-I: Nine polyketides with anti-inflammatory activity from a soil fungus Talaromyces sp. KYS-41

A chemical investigation into fermentation product of Talaromyces sp. KYS-41, a fungus isolated from Kunyu Mountain soil, resulted in the discovery and identification of 27 polyketides. Notably, talaromyketides A-I (1-9) are reported for the first time, with talaromyketides A-C (1-3) being three pair of enantiomers. Talaromyketides A-D (1-4) display novel frameworks and are regarded as products resulting from oxidative ring-opening and/or subsequent rearrangement of the bibenzyl derivatives. Talaromyketide A (1) exhibits a scaffold comprising an isochroman-1,4-dione, whereas talaromyketide B (2) showcases the structural backbone of a naphthalen-1(4H)-one. Talaromyketides C (3) and D (4) are the outcomes of oxidative ring-opening of one of the phenyl rings in bibenzyl derivatives. Biological evaluations demonstrated that compounds 2b, 9, and 18-21 show significant anti-inflammatory activity with IC50 values within 10 μM. By inhibiting the activation of NF-κB/MAPK signaling pathways, (-)-1S-talaromyketide B (2b) is involved in suppression of inflammatory response and shows significant pharmacological effects in vivo on zebrafish model.

Harnessing Functional Food Sources: Deriving Anti-Inflammatory and Antibacterial Naphthalene Derivatives from the Edible Bulbs of Eleutherine bulbosa

The red bulbs of Eleutherine bulbosa, commonly used as a daily dietary ingredient in cooking, are well-known for their rich nutritional profile and potential medicinal properties. This study focused on identifying bioactive components from E. bulbosa by a bioactivity-guided approach combined with global natural products' social molecular networking, which led to the characterization of 12 new naphthalene derivatives, eleuthalenes A-L (1-12), and 22 known analogues. The structures of these compounds were determined through spectroscopic data, X-ray crystallography, and quantum chemical calculations. The anti-inflammatory and antibacterial activities of these compounds were evaluated, with some demonstrating significant anti-inflammatory and moderate antibacterial activities. Further studies revealed that the most potent compound 5 displayed an anti-inflammatory effect in LPS-induced RAW 264.7 cells by suppressing the NF-κB/MAPK and activating Nrf2/Keap1 signaling pathways. The results suggested that bioactive naphthalene derivatives are the major pharmacodynamic substances of E. bulbosa.

Comprehensive Metabolomics Profiling and Bioactivity Study of Lycium shawii (Awsaj) Extracts with Particular Emphasis on Potential Anti-Malarial Properties

Background/Objectives: Although malaria is one of the oldest known human diseases, it continues to be a major global health challenge. According to UNICEF, the global malaria mortality rate exceeded 600,000 annually in 2022, which includes more than 1000 children dying each day. This study aimed to investigate the comprehensive chemical profile and biological activities, particularly the antimalarial activity, of Lycium shawii (Awsaj), a shrub traditionally used in the Arabian Peninsula, Middle East, India, and Africa to treat a myriad of ailments. Methods: Crude extracts of L. shawii were prepared using water, ethanol, methanol, and acetone. Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) were utilized to perform untargeted metabolomics to maximize metabolite detection and tentatively identify bioactive phytochemicals. The total phenolic content (TPC) was measured for each extract, and bioassays were conducted to evaluate their antimalarial, antibacterial, and anti-inflammatory activities, particularly those of the water extract, which is the traditional method of consumption in Arabian folk medicine. Results: A total of 148 metabolites were detected, 45 of which were classified as phytochemicals. The bioassays revealed that the water extract that is traditionally used showed promising antimalarial potential by significantly inhibiting β-hematin formation in vitro at 1 mg/mL (with an absorbance of 0.140 ± 0.027). This is likely due to the rich presence of quinoline in the aqueous extract among several other bioactive phytochemicals, such as phenylpropanoids, alkaloids, flavonoids, and benzenoids. However, their anti-inflammatory and antibacterial activities were found to be weak, with only a minor inhibition of nitric oxide (NO) production in LPS-induced RAW 264.7 cells at a concentration of 500 µg/mL and weak antibacterial effects against pathogens like P. aeruginosa, MRSA, A. baumannii, and K. pneumoniae with an MIC of 500 μg/mL. The results also revealed that the methanolic extract had the highest TPC at 26.265 ± 0.005 mg GAE/g. Conclusions: The findings support the traditional medicinal use of L. shawii and highlight its potential as a source of novel therapeutic compounds, particularly for treating malaria. This study encourages further research to isolate and develop effective plant-based anti-malarial agents.

GC-MS/MS Analysis and Wound Repair Potential of Urtica dioica Essential Oil: In silico Modeling and In vivo Study in Rats

BACKGROUND

The study aimed to assess the antioxidant and wound healing properties of Urtica dioica essential oil (UDEO) through a comprehensive evaluation involving in silico, in vitro, and in vivo analyses. The phytochemistry of UDEO was also investigated to identify trace compounds crucial.

METHODS

Various injection methods of the multimode inlet (MMI) in chromatography were investigated to attain lower instrumental detection limits. Subsequently, in silico studies were employed to delve deeper into the potential biological activities of the identified compounds. Standard antioxidative tests, encompassing ABTS•+ and TAC, were performed. In vivo tests centered on wound healing were implemented using rat models. The rats were randomly allocated to four groups: saline solution, vaseline vehicle, cytol centella, and 5% UDEO ointment. Wound healing progress was evaluated through a chromatic study.

RESULTS

Gas chromatography combined with triple quadrupole mass spectrometry (GC-MS/MS) analysis revealed the presence of 97 thermolabile compounds in UDEO. Subsequent in silico studies unveiled the potential of identified compounds to inhibit COX-2, TNF-α, and IL-6, suggesting a possible enhancement of anti-inflammatory responses and healing processes. In vitro tests elucidated the notable antioxidant capacity of UDEO, a finding reinforced by wound healing data, revealing a substantial closure rate of 89% following the topical application of UDEO. Notably, fibrinogen and C-reactive protein (CRP) levels were significantly reduced, indicating minimized oxidative stress damage compared to control. Additionally, UDEO exhibited an increase in antioxidant enzyme activities compared to control.

CONCLUSION

The study concludes that UDEO possesses significant antioxidant and wound-healing properties, supported by its rich phytochemical composition. The findings suggest its potential application in therapeutic interventions for oxidative stress and inflammatory conditions.

Pyrogallol promotes growth arrest by activating the p53-mediated up-regulation of p21 and p62/SQSTM1-dependent degradation of β-catenin in nonsmall cell lung cancer cells

Pyrogallol (1,2,3-trihydroxybenzene), a polyphenolic natural compound, has attracted considerable attention with regard to its potential anticancer activity. However, further study is needed to elucidate the underlying mechanism related to the antiNSCLC activity of pyrogallol and provide a comprehensive theoretical basis for better clinical utilization of pyrogallol. Our current study aims to investigate the effects and potential underlying mechanisms of pyrogallol on the inhibition of NSCLC growth. Our results showed that pyrogallol treatment induced cell cycle arrest at the G2/M phase and apoptosis in two different NSCLC cell lines. Mechanistically, we found that the induction of cell cycle arrest in NSCLC cells at the G2/M phase by pyrogallol was due to the upregulation of p21 in a p53-dependent manner. And blockade of p53 and p21 effectively abolished the cell cycle arrest at the G2/M phase. Meanwhile, p53 inhibition has been found to abrogate the pyrogallol-induced apoptosis of the two NSCLC cells. Moreover, we revealed that the inhibitory effects of pyrogallol on β-catenin signaling resulted from autophagy initiation depending on p53 activation, accompanied by an increase in p62/SQSTM1 expression, thus p62 subsequently interacting with ubiquitinated β-catenin and facilitating autophagic destruction of β-catenin. Furthermore, in vivo experiments demonstrated that pyrogallol exerted growth inhibition on NSCLC with low toxicity through the same molecular mechanism as observed in vitro. Our findings could contribute to the understanding of the mechanism by which pyrogallol negatively regulates NSCLC growth, which could be effective in treating NSCLC.

Pyrogallol protects against influenza A virus-triggered lethal lung injury by activating the Nrf2-PPAR-γ-HO-1 signaling axis

Pyrogallol, a natural polyphenol compound (1,2,3-trihydroxybenzene), has shown efficacy in the therapeutic treatment of disorders associated with inflammation. Nevertheless, the mechanisms underlying the protective properties of pyrogallol against influenza A virus infection are not yet established. We established in this study that pyrogallol effectively alleviated H1N1 influenza A virus-induced lung injury and reduced mortality. Treatment with pyrogallol was found to promote the expression and nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) and peroxisome proliferator-activated receptor gamma (PPAR-γ). Notably, the activation of Nrf2 by pyrogallol was involved in elevating the expression of PPAR-γ, both of which act synergistically to enhance heme oxygenase-1 (HO-1) synthesis. Blocking HO-1 by zinc protoporphyrin (ZnPP) reduced the suppressive impact of pyrogallol on H1N1 virus-mediated aberrant retinoic acid-inducible gene-I-nuclear factor kappa B (RIG-I-NF-κB) signaling, which thus abolished the dampening effects of pyrogallol on excessive proinflammatory mediators and cell death (including apoptosis, necrosis, and ferroptosis). Furthermore, the HO-1-independent inactivation of janus kinase 1/signal transducers and activators of transcription (JAK1/STATs) and the HO-1-dependent RIG-I-augmented STAT1/2 activation were both abrogated by pyrogallol, resulting in suppression of the enhanced transcriptional activity of interferon-stimulated gene factor 3 (ISGF3) complexes, thus prominently inhibiting the amplification of the H1N1 virus-induced proinflammatory reaction and apoptosis in interferon-beta (IFN-β)-sensitized cells. The study provides evidence that pyrogallol alleviates excessive proinflammatory responses and abnormal cell death via HO-1 induction, suggesting it could be a potential agent for treating influenza.

Potential antioxidative and anti-hyperuricemic components in Rodgersia podophylla A. Gray revealed by bio-affinity ultrafiltration with SOD and XOD

Rodgersia podophylla A. Gray (R. podophylla) is a traditional Chinese medicine with various pharmacological effects. However, its antioxidant and anti-hyperuricemia components and mechanisms of action have not been explored yet. In this study, we first assessed the antioxidant potential of R. podophylla with 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric ion reducing antioxidant power (FRAP) assays. The results suggested that the ethyl acetate (EA) fraction of R. podophylla not only exhibited the strongest DPPH, ABTS radical scavenging and ferric-reducing activities, but also possessed the highest total phenolic and total flavonoid contents among the five fractions. After that, the potential superoxide dismutase (SOD) and xanthine oxidase (XOD) ligands from the EA fraction were quickly screened and identified through the bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS). Accordingly, norbergenin, catechin, procyanidin B2, 4-O-galloylbergenin, 11-O-galloylbergenin, and gallic acid were considered to be potential SOD ligands, while gallic acid, 11-O-galloylbergenin, catechin, bergenin, and procyanidin B2 were recognized as potential XOD ligands, respectively. Moreover, these six ligands effectively interacted with SOD in molecular docking simulation, with binding energies (BEs) ranging from -6.85 to -4.67 kcal/mol, and the inhibition constants (Ki) from 9.51 to 379.44 μM, which were better than the positive controls. Particularly, catechin exhibited a robust binding affinity towards XOD, with a BE value of -8.54 kcal/mol and Ki value of 0.55 μM, which surpassed the positive controls. In conclusion, our study revealed that R. podophylla possessed remarkable antioxidant and anti-hyperuricemia activities and that the UF-LC-MS method is suitable for screening potential ligands for SOD and XOD from medicinal plants.

Paricalcitol Ameliorates Acute Kidney Injury in Mice by Suppressing Oxidative Stress and Inflammation via Nrf2/HO-1 Signaling

Effective and targeted prevention and treatment methods for acute kidney injury (AKI), a common clinical complication, still needs to be explored. Paricalcitol is a biologically active chemical that binds to vitamin D receptors in the body to exert anti-oxidant and anti-inflammatory effects. However, the molecular mechanism of the effect of paricalcitol on AKI remains unclear. The current study uses a paricalcitol pretreatment with a mouse AKI model induced by cisplatin to detect changes in renal function, pathology and ultrastructure. Results showed that paricalcitol significantly improved renal function in mice and reduced inflammatory cell infiltration and mitochondrial damage in renal tissue. Furthermore, paricalcitol markedly suppressed reactive oxygen species and malondialdehyde levels in the kidneys of AKI mice and increased the levels of glutathione, superoxide dismutase, Catalase and total anti-oxidant capacity. In addition, we detected renal necrosis and inflammation-related proteins in AKI mice by immunofluorescence and Western blot, and found that their levels were markedly decreased after paricalcitol pretreatment. Moreover, paricalcitol promotes nuclear factor erythroid 2-related factor 2 (Nrf2) in the nucleus and activates the Nrf2/heme oxygenase-1 (HO-1) signaling pathway; while HO-1 is inhibited, the protective effect of paricalcitol on the kidney is attenuated. In conclusion, paricalcitol exerts a renoprotective effect by decreasing renal oxidative injury and inflammation through Nrf2/HO-1 signaling, providing a new insight into AKI prevention.

Anti-Inflammatory Activity of Geraniol Isolated from Lemon Grass on Ox-LDL-Stimulated Endothelial Cells by Upregulation of Heme Oxygenase-1 via PI3K/Akt and Nrf-2 Signaling Pathways

Among the world's leading causes of cardiovascular disease, atherosclerosis is a chronic inflammatory disorder that affects the arteries. Both vasodilation and vasoconstriction, low levels of nitric oxide and high levels of reactive oxygen species and pro-inflammatory factors characterize dysfunctional blood vessels. Hypertension, and atherosclerosis, all start with this dysfunction. Geraniol, a compound of acyclic monoterpene alcohol, found in plants such as geranium, lemongrass and rose, is a primary constituent of essential oils. It shows a variety of pharmacological properties. This study aimed to investigate the impact of geraniol on Ox-LDL-induced stress and inflammation in human umbilical vein endothelial cells. In this study, HUVECs were treated with Ox-LDL or geraniol at different dose concentrations. MTT assay, Western blot, ROS generation and DNA fragmentation were used to evaluate geraniol's effects on Ox-LDL-induced HUVECs inflammation. The results show that geraniol pre-incubation ameliorates Ox-LDL-mediated HUVECs cytotoxicity and DNA fragmentation. The geraniol inhibited the production of pro-inflammatory cytokines by Ox-LDL, including TNF-α, IL-6 and IL-1β. In Ox-LDL-stimulated HUVECs, geraniol suppresses the nuclear translocation and activity of NF-ᴋB as well as phosphorylation of IkBα. Moreover, geraniol activated the PI3K/AKT/NRF2 pathway in HUVECs, resulting in an increase in the expression of HO-1. Taking our data together, we can conclude that, in HUVECs, geraniol inhibits Ox-LDL-induced inflammation and oxidative stress by targeting PI3/AKT/NRF2.

Circulating (Poly)phenol Metabolites: Neuroprotection in a 3D Cell Model of Parkinson's Disease

SCOPE

Diets rich in (poly)phenols have been associated with positive effects on neurodegenerative disorders, such as Parkinson's disease (PD). Several low-molecular weight (poly)phenol metabolites (LMWPM) are found in the plasma after consumption of (poly)phenol-rich food. It is expected that LMWPM, upon reaching the brain, may have beneficial effects against both oxidative stress and neuroinflammation, and possibly attenuate cell death mechanisms relate to the loss of dopaminergic neurons in PD.

METHODS AND RESULTS

This study investigates the neuroprotective potential of two blood-brain barrier permeant LMWPM, catechol-O-sulfate (cat-sulf), and pyrogallol-O-sulfate (pyr-sulf), in a human 3D cell model of PD. Neurospheroids were generated from LUHMES neuronal precursor cells and challenged by 1-methyl-4-phenylpyridinium (MPP⁺ ) to induce neuronal stress. LMWPM pretreatments were differently neuroprotective towards MPP⁺ insult, presenting distinct effects on the neuronal transcriptome. Particularly, cat-sulf pretreatment appeared to boost counter-regulatory defense mechanisms (preconditioning). When MPP⁺ is applied, both LMWPM positively modulated glutathione metabolism and heat-shock response, as also favorably shifting the balance of pro/anti-apoptotic proteins.

CONCLUSIONS

Our findings point to the potential of LMWPM to trigger molecular mechanisms that help dopaminergic neurons to cope with a subsequent toxic insult. They are promising molecules to be further explored in the context of preventing and attenuating parkinsonian neurodegeneration.

Role of PI3K/Akt-Mediated Nrf2/HO-1 Signaling Pathway in Resveratrol Alleviation of Zearalenone-Induced Oxidative Stress and Apoptosis in TM4 Cells

Zearalenone (ZEA) is a common mycotoxin that induces oxidative stress (OS) and affects the male reproductive system in animals. Resveratrol (RSV) has good antioxidant activity and can activate nuclear factor erythroid 2-related factor (Nrf2) to protect cells through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. The objective of this study was to investigate the protective effect and the mechanism of RSV on OS and apoptosis in TM4 cells induced by ZEA. Prior to being exposed to ZEA, TM4 cells were pretreated with RSV or the PI3K/Akt inhibitor LY294002. Cell viability was measured by Cell Counting Kit-8 (CCK-8) assays. Flow cytometry was used to determine the level of apoptosis and intracellular reactive oxygen species (ROS). The expression of poly ADP-ribose polymerase (PARP), caspase-3, BCL2-associated X (Bax)/B-cell lymphoma-2 (Bcl-2), and PI3K/Akt-mediated Nrf2/heme oxygenase 1 (HO-1) signaling pathway-related proteins was evaluated by Western blotting. Nrf2 siRNA transfection and LY294002 treatment were used to investigate the role of the Nrf2/HO-1 and PI3K/Akt signaling pathways in RSV alleviation of ZEA-induced OS. The results showed that pretreatment with RSV significantly reduced the expression of apoptosis-related proteins and increased cell viability. Catalase (CAT) activity and glutathione (GSH) levels were also increased, whereas malondialdehyde (MDA) and ROS levels decreased (p < 0.05). RSV also upregulated Akt phosphorylation, Nrf2 nuclear translocation, and HO-1 expression under conditions of OS (p < 0.05). Transfection with Nrf2 siRNA abolished the protective effects of RSV against ZEA-induced cytotoxicity (p < 0.05), ROS accumulation (p < 0.05), and apoptosis (p < 0.05). LY294002 completely blocked the RSV-mediated increase in Nrf2 nuclear translocation (p < 0.05), HO-1 expression (p < 0.05), and cytoprotective activity (p < 0.05). Collectively, the above findings indicate that RSV can protect against ZEA-induced OS and apoptosis in TM4 cells by PI3K/Akt-mediated activation of the Nrf2/HO-1 signaling pathway.

Extracts of Ginkgo flavonoids and ginkgolides improve cerebral ischaemia-reperfusion injury through the PI3K/Akt/Nrf2 signalling pathway and multicomponent in vivo processes

BACKGROUND

Cerebral ischaemia-reperfusion injury (CIRI) is a common disease characterized by severe attacks and a high disabling rate worldwide. Oxidative stress injury has been proposed as a major risk factor for CIRI. Ginkgo biloba extract (GBE) has been shown to elicit vascular protective effects, the main components of which are Ginkgo flavonoids (GF) and ginkgolides (GL). Our previous study showed that GF and GL played a central role in protecting CIRI, but the mechanism remains unclear. This study aimed to further reveal the protective effect mechanism of GF and GL in rats with CIRI.

METHODS

The antioxidant activity in vitro was assessed by the DPPH method. The model used in this study was established by middle cerebral artery occlusion (MCAO) and reperfusion; the level of CIRI was assessed by nerve function score and TTC staining; we measured the oxidative stress indices in the brain cortex, including LDH, GSH-Px, and the protein contents of Akt, p-Akt, Nrf2, and HO-1; HPLC-MS was used to detect drug concentrations in rat plasma at different times after administration of GF and GL; and the pharmacokinetic parameters of each component were calculated by Drug and Statistic Version 3.2.6 (DAS 3.2.6) software and SPSS 17.0.

RESULTS

Regarding the DPPH free radical scavenging ability, GF performed better free radical scavenging ability than GL. In terms of the nerve function score and TTC staining, there were no statistically significant differences among the GF, GL and combined groups; however, there were significant differences in reducing the activity of LDH and increasing the activity of GSH-Px in the three administration groups. For the expression of Akt, p-Akt, Nrf2, and HO-1, the combined group had a significant effect compared with that in the GF or GL group. In addition, there was a significant multicomponent interaction in vivo in the combined group compared with the GF or GL group.

CONCLUSION

After GF and GL were used in combination, the effect of anti-CIRI was more pronounced. This result indicated that GF and GL might improve CIRI by activating the PI3K/Akt/Nrf2 signalling pathway and promoting multicomponent interactions in vivo.

Moringa oleifera Lam. seed extract protects kidney function in rats with diabetic nephropathy by increasing GSK-3β activity and activating the Nrf2/HO-1 pathway

BACKGROUND

Moringa oleifera Lam. (M. oleifera) seeds are widely used in traditional folk medicine and as nutritional supplements in the Middle East, Africa, and other regions. Published research showed that M. oleifera seeds (MOS) have pharmacological activities such as blood glucose-lowering, anti-inflammatory, and antitumor effects. However, experimental evidence on the use of MOS to treat diabetic nephropathy and its underlying mechanisms were rarely reported.

PURPOSE

To evaluate the therapeutic effects of MOS extract on the kidneys of high-fat diet (HFD)-fed rats with streptozotocin-induced diabetic nephropathy and reveal its underlying mechanisms.

STUDY DESIGN

HFD-fed rats with streptozotocin-induced diabetic nephropathy and high-glucose induced Human Renal Mesangial Cells (HRMC) were used to explore the protective effect of MOS on diabetic nephropathy in vivo and in vitro.

METHODS

HRMC were used to preliminarily evaluate the effect of MOS extract under high glucose conditions. For the in vivo study, rats were divided into the following 6 groups (n = 5): normal control group (NC), diabetic nephropathy model group (DN), high dose of MOS-treatment group (DN + MOS-H, 200 mg/kg/d); medium dose of MOS-treatment group (DN + MOS-M, 100 mg/kg/d); low dose of MOS-treatment group (DN + MOS-l, 50 mg/kg/d), and metformin-treatment group (DN + MET, 200 mg/kg/d). After 4 weeks of treatment, the damage caused by DN was assessed based on the related parameters of urine and blood. Periodic acid-Schiff (PAS) staining and hematoxylin and eosin (HE) staining were used to assess pathological tissue damage. Immunohistochemistry was used to detect nuclear factor erythroid-derived 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and phosphorylated-glycogen synthase kinase-3beta (P-GSK-3β) levels, whereas western blotting was used to detect Nrf2, HO-1, nephrin, GSK-3β, and p-GSK-3β levels.

RESULTS

MOS extract could inhibit the proliferation of HRMCs induced by high glucose levels. Compared with the rats in the DN group, MOS not only significantly reduced blood glucose levels and oxidative stress in the experimental rats but also improved their kidney function and reduced kidney tissue damage. Additionally, MOS extract increased GSK-3β activity and the expression of Nrf2 and HO-1.

CONCLUSIONS

This study showed that MOS could activate GSK-3β and Nrf2/HO-1 pathways to exert antioxidant and anti-renal fibrosis activities, and delay the progression of diabetic nephropathy.

α‑rhamnrtin‑3‑α‑rhamnoside exerts anti‑inflammatory effects on lipopolysaccharide‑stimulated RAW264.7 cells by abrogating NF‑κB and activating the Nrf2 signaling pathway

α-rhamnrtin-3-α-rhamnoside (ARR) is the principal compound extracted from Loranthus tanakae Franch. & Sav. However, its underlying pharmacological properties remain undetermined. Inflammation is a defense mechanism of the body; however, the excessive activation of the inflammatory response can result in physical injury. The present study aimed to investigate the effects of ARR on lipopolysaccharide (LPS)-induced RAW264.7 macrophages and to determine the underlying molecular mechanism. A Cell Counting Kit-8 assay was performed to assess cytotoxicity. Nitric oxide (NO) production was measured via a NO colorimetric kit. Levels of prostaglandin E2 (PGE₂) and proinflammatory cytokines, IL-1β and IL-6, were detected using ELISAs. Reverse transcription-quantitative (RT-q)PCR analysis was performed to detect the mRNA expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6 and IL-1β in LPS-induced RAW246.7 cells. Western blotting, immunofluorescence and immunohistochemistry analyses were performed to measure the expression levels of NF-κB and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins to elucidate the molecular mechanisms of the inflammatory response. The results of the cytotoxicity assay revealed that doses of ARR ≤200 µg/ml exhibited no significant effect on the viability of RAW264.7 cells. The results of the Griess assay demonstrated that ARR inhibited the production of NO. In addition, the results of the ELISAs and RT-qPCR analysis discovered that ARR reduced the production of the proinflammatory cytokines, IL-1β and IL-6, as well as the proinflammatory mediators, PGE₂, iNOS and COX-2, in LPS-induced RAW264.7 cells. Immunohistochemical analysis demonstrated that ARR inhibited LPS-induced activation of TNF-associated factor 6 (TRAF6) and NF-κB p65 signaling molecules, while reversing the downregulation of the NOD-like receptor family CARD domain containing 3 (NLRC3) signaling molecule, which was consistent with the results of the western blotting analysis. Immunofluorescence results indicated that ARR reduced the increase of NF-κB p65 nuclear expression induced by LPS. Furthermore, the results of the western blotting experiments also revealed that ARR upregulated heme oxygenase-1, NAD(P)H quinone dehydrogenase 1 and Nrf2 pathway molecules. In conclusion, the results of the present study suggested that ARR may exert anti-inflammatory effects by downregulating NF-κB and activating Nrf2-mediated inflammatory responses, suggesting that ARR may be an attractive anti-inflammatory candidate drug.

Apomorphine Reduces A53T α-Synuclein-Induced Microglial Reactivity Through Activation of NRF2 Signalling Pathway

The chiral molecule, apomorphine, is currently used for the treatment of Parkinson’s disease (PD). As a potent dopamine receptor agonist, this lipophilic compound is especially effective for treating motor fluctuations in advanced PD patients. In addition to its receptor-mediated actions, apomorphine has also antioxidant and free radical scavenger activities. Neuroinflammation, oxidative stress, and microglia reactivity have emerged as central players in PD. Thus, modulating microglia activation in PD may be a valid therapeutic strategy. We previously reported that murine microglia are strongly activated upon exposure to A53T mutant α-synuclein. The present study was designed to investigate whether apomorphine enantiomers could modulate this A53T-induced microglial activation. Taken together, the results provided evidence that apomorphine enantiomers decrease A53T-induced microgliosis, through the activation of the NRF2 signalling pathway, leading to a lower pro-inflammatory state and restoring the phagocytic activity. Suppressing NRF2 recruitment (trigonelline exposure) or silencing specifically Nfe2l2 gene (siRNA treatment) abolished or strongly decreased the anti-inflammatory activity of apomorphine. In conclusion, apomorphine, which is already used in PD patients to mimic dopamine activity, may also be suitable to decrease α-synuclein-induced microglial reactivity.

Anti-Oxidant and Anti-Inflammatory Substance Generated Newly in Paeoniae Radix Alba Extract Fermented with Plant-Derived Lactobacillus brevis 174A

Fermentation of medicinal herbs can be a significant technique to obtain bioactive compounds. Paeoniae Radix (PR) used in the present study is a well-known herbal medicine that exhibits anti-inflammatory and immunomodulatory activity. The aim of this study is to explore the possibility that a bioactive compound is newly generated in PR extract by fermentation with a plant-derived lactic acid bacteria Lactobacillus brevis 174A. We determined the anti-inflammatory activities in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The PR extract fermented with Lactobacillus brevis 174A markedly increased the total phenolic content, decreased intracellular ROS levels, inhibited the release of nitric oxide (NO). It also suppressed inflammatory cytokines IL-6, TNF-ɑ, while simultaneously downregulating the gene expressions of iNOS, IL-6, TNF-ɑ, and IL-1β compared to the unfermented PR extract. Furthermore, the bioactive compound newly generated from the fermentation was identified as pyrogallol. It inhibits the inflammatory responses in a dose-dependent manner suggesting that fermentation of the herbal extract used as a medium together with the plant-derived lactic acid bacterial strain may be a practical strategy to produce medicines and supplements for healthcare.

Glaucocalyxin A Attenuates Allergic Responses by Inhibiting Mast Cell Degranulation through p38MAPK/NrF2/HO-1 and HMGB1/TLR4/NF-κB Signaling Pathways

Glaucocalyxin A (GLA) has various pharmacological effects like antioxidation, immune regulation, and antiatherosclerosis. Here, in this study, the effect and mechanism of GLA on mast cell degranulation were studied. The results of the anti-DNP IgE-mediated passive cutaneous anaphylaxis (PCA) showed that GLA dramatically inhibited PCA in vivo, as evidenced by reduced Evans blue extravasation and decreased ear thickness. In addition, GLA significantly reduced the release of histamine and β-hexosaminidase, calcium influx, cytokine (IL-4, TNF-α, IL-1β, IL-13, and IL-8) production in the RBL-2H3 (rat basophilic leukemia cells), and RPMCs (peritoneal mast cells) in vitro. Moreover, we further investigated the regulatory mechanism of GLA on antigen-induced mast cells by Western blot, which showed that GLA inhibited FcεRI-mediated signal transduction and invalidated the phosphorylation of Syk, Fyn, Lyn, Gab2, and PLC-γ1. In addition, GLA inhibited the recombinant mouse high mobility group protein B1- (HMGB1-) induced mast cell degranulation through limiting nuclear translocation of NF-κBp65. Treatment of mast cells with siRNA-HMGB1 significantly inhibited HMGB1 levels, as well as MyD88 and TLR4, decreased intracellular calcium levels, and suppressed the release of β-hexosaminidase. Meanwhile, GLA increased NrF2 and HO-1 levels by activating p38MAPK phosphorylation. Consequently, these data suggest that GLA regulates the NrF2/HO-1 signaling pathway through p38MAPK phosphorylation and inhibits HMGB1/TLR4/NF-κB signaling pathway to reduce mast cell degranulation and allergic inflammation. Our findings could be used as a promising therapeutic drug against allergic inflammatory disease.

Lycopene inhibits IL-1β-induced inflammation in mouse chondrocytes and mediates murine osteoarthritis

Osteoarthritis (OA) is a common chronic degenerative condition in the elderly, in which inflammation plays a key role in disease pathology. Lycopene (Lye), a member of the carotenoid family, has been reported to have anti‐inflammatory effects. The purpose of this study was to investigate the effect of Lye on the inflammation of chondrocytes and the mouse OA model. Chondrocytes were treated with interleukin (IL)‐1β, and the mouse OA model was induced by the surgical destabilization of the medial meniscus (DMM). The results showed that Lye could inhibit the expression of inflammatory factors and alleviate the degradation of extracellular matrix (ECM). Additionally, Lye could activate the Nrf2/HO‐1 pathway and reverse the activations of NF‐κB and STAT3 signal pathway induced by IL‐1β, suggesting that its anti‐inflammatory effect may be mediated via these pathways. The animal experiments showed that Lye could decrease the Osteoarthritis Research Society International (OARSI) scores of the knee, indicating that it could inhibit the occurrence and development of OA in mouse. Overall, our results indicated that Lye might be used as a novel drug for OA treatment.

Anti-Inflammatory Activity of Extracts and Pure Compounds Derived from Plants via Modulation of Signaling Pathways, Especially PI3K/AKT in Macrophages

The plant kingdom is a source of important therapeutic agents. Therefore, in this review, we focus on natural compounds that exhibit efficient anti-inflammatory activity via modulation signaling transduction pathways in macrophage cells. Both extracts and pure chemicals from different species and parts of plants such as leaves, roots, flowers, barks, rhizomes, and seeds rich in secondary metabolites from various groups such as terpenes or polyphenols were included. Selected extracts and phytochemicals control macrophages biology via modulation signaling molecules including NF-κB, MAPKs, AP-1, STAT1, STAT6, IRF-4, IRF-5, PPARγ, KLF4 and especially PI3K/AKT. Macrophages are important immune effector cells that take part in antigen presentation, phagocytosis, and immunomodulation. The M1 and M2 phenotypes are related to the production of pro- and anti-inflammatory agents, respectively. The successful resolution of inflammation mediated by M2, or failed resolution mediated by M1, may lead to tissue repair or chronic inflammation. Chronic inflammation is strictly related to several disorders. Thus, compounds of plant origin targeting inflammatory response may constitute promising therapeutic strategies.