Ethnopharmacological validation of Karkataka Taila-An edible crab Rasayana in rotenone-induced in vitro and in vivo models of Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

'Karkataka Taila (KT), an ancient Ayurvedic Rasayana comprising the edible freshwater crab Scylla serrata Forskal flesh, is still used by local traditional practitioners in Kerala state to treat tremors and palsy. In the scientific community, it becomes less exposed due to the lack of adequate scientific validations and brief reports. There has been no published research on the effectiveness of KT in treating Parkinson's disease (PD).

PURPOSE

The purpose of the current research work was to investigate the anti-Parkison's potential of KT against rotenone-induced neurotoxicity in SH-SY5Y cell lines and rat model of PD and investigate underlying molecular mechanisms.

MATERIALS AND METHODS

The components of KT have been identified by gas chromatography-mass spectroscopy (GC-MS). The neuroprotective activity of KT was assessed using SH-SY5Y cell lines and rats against rotenone-induced PD. The parameters used for asses the neuroprotection are antioxidant markers (ROS and SOD), anti-inflammatory markers (IL-6, IL-1β, TNF-α, and nitrite), and dopamine levels. Behavioral evaluation and rat brain histopathology were carried out to further support the neuroprotection.

RESULT

Analysis using GC-MS revealed 36 constituents in KT. In vitro, the KT displayed considerable neuroprotective effects in terms of decreasing oxidative stress (ROS and SOD), neuroinflammation (IL-6, IL-1β, TNF-α, and nitrite), and elevating dopamine concentration. In vivo data showing improvements in histopathological and biochemical parameters confirmed the in vitro study findings, and in terms of behavioral assays, KT displayed significant activity.

CONCLUSION

GC-MS profiling was used to identify the bioactive compounds of KT with antioxidant, anti-inflammatory, and neuroprotective properties. As a result, they may be responsible for the therapeutic effects of KT on PD.

Targeting cardiovascular risk factors with eugenol: an anti-inflammatory perspective

Inflammation is a multifaceted biological reaction to a wide range of stimuli, and it has been linked to the onset and progression of chronic diseases such as heart disease, cancer, and diabetes. Inflammatory markers found in the blood, including C-reactive protein, serum amyloid A, fibrinogen, plasma viscosity, erythrocyte sedimentation rate, interleukin-6, and soluble adhesion molecules (like intercellular adhesion molecule-1 and vascular cell adhesion molecule-1), are risk factors for cardiovascular diseases such as coronary heart disease, stroke, and peripheral arterial disease. These markers play a crucial role in understanding and assessing cardiovascular health. Due to this complicated relationship between inflammation and cardiovascular disease, anti-inflammatory agents of natural origin have been the subject of many preclinical and clinical studies in recent years. Eugenol is a natural phenolic compound found in clove oil, nutmeg oil, cinnamon oil, and bay leaf oil, as well as other essential oils. Eugenol has been shown to have anti-inflammatory properties in many forms of experimental inflammation. It may scavenge free radicals, which contribute to inflammation and tissue damage. Various studies also suggest that eugenol can limit the production of inflammatory mediators such as prostaglandins, cytokines, and chemokines. Animal models of arthritis, colitis, and lung damage, as well as human clinical studies, have shown that eugenol has phenomenal anti-inflammatory properties. These properties suggest that eugenol may be able to reduce the risk of cardiovascular diseases.

Diclofenac and eugenol hybrid with enhanced anti-inflammatory activity through activating HO-1 and inhibiting NF-κB pathway in vitro and in vivo

A series of diclofenac hybrid molecules were synthesized and evaluated for their NO-inhibitory ability in LPS-induced RAW 264.7 macrophage cells. Among them, compound 1 showed the highest NO-inhibitory ability (approximately 66%) and no significant cytotoxicity. Compound 1 exhibited superior NF-κB-inhibitory ability compared to diclofenac through the activation of Nrf2/HO-1 signaling pathway in RAW 264.7. 20 mg/kg compound 1 resulted in remarkable colitis improvement in dextran sulfate sodium (DSS)-induced mice model by up-regulating HO-1 and down-regulating phosphorylation level of NF-κB p65. Moreover, 50 mg/kg dose of compound 1 showed a lower ulcerogenic potential compared to diclofenac in rats. The diclofenac-eugenol hybrid (compound 1) may serve as a novel anti-inflammatory agent based on its role in inhibiting the NF-κB signaling pathway and activating HO-1 expression with no toxicity in vitro and in vivo.

Analytical determination, antioxidant and anti-inflammatory activities of Bhamrung-Lohit a traditional Thai medicine

Background and purpose

Bhamrung-Lohit (BRL) remedy is a traditional Thai medicine (TTM). There are few reports of biological activity, the activity of its constituent plants, or quantitative analytical methods for the content of phytochemicals. In this study, we investigated antioxidant, anti-inflammatory activity, and total phenolic and flavonoid content and validated a new analytical method for BRL.

Experimental approach

Antioxidant activity was evaluated by a 2,2-diphenyl-1-picrylhydrazyl (DPPH and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging. The cellular antioxidant activity was evaluated by inhibition of the superoxide anion (O2●-) production from HL-60 cells and anti-inflammatory activity by inhibition of nitric oxide production in RAW264.7 cells. The total phenolic and flavonoid contents were analyzed using the Folin-Ciocalteu method and an aluminum chloride colorimetric assay, respectively. Validated analytical procedures were conducted according to International Conference on Harmonization (ICH) guidelines.

Findings/Results

An ethanolic extract of BRL exerted potent DPPH radical scavenging activity and moderate antioxidant and anti-inflammatory activity. Caesalpinia sappan exerted the greatest effect and the highest content of total phenolics and flavonoids. The HPLC method validated parameters that complied with ICH requirements. Each peak showed selectivity with a baseline resolution of 2.0 and precision was less than 2.0% CV. The linearity of all compounds was > 0.999 and the recovery % was within 98.0%-102.0%. The validated results demonstrated specificity/selectivity, linearity, precision, and accuracy with appropriate LOD and LOQ.

Conclusion and implication

BRL remedy, a TTM demonstrated antioxidant and anti-inflammatory properties. This study is the first report on the biological activity and the validation of an HPLC method for BRL remedy.

Effects of Eugenol and Dehydrodieugenol B from Nectandra leucantha against Lipopolysaccharide (LPS)-Induced Experimental Acute Lung Inflammation

Acute lung injury (ALI) is an important public health problem. The present work investigated whether dehydrodieugenol B treatment, a compound isolated from Brazilian plant Nectandra leucantha (Lauraceae), modulates experimental ALI and compared the observed effects to eugenol. Effects of dehydrodieugenol B in vitro in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells were evaluated. The lung and systemic inflammatory profile, lung function, and possible mechanisms involved in BALB/C male mice (6-8 weeks) with ALI induced by LPS instillation (5 mg/kg) was assayed. Dehydrodieugenol B did not affect the cell viability and inhibited the increase in NO release and IL-1β and IL-6 gene expression induced by LPS. In vivo, both compounds reduced lung edema, inflammatory cells, and the IL-6 and IL-1 β levels in bronchoalveolar lavage fluid, as well as reduced inflammatory cell infiltration and those positive to iNOS, MMP-9, and TIMP-1, and reduced the collagen content and the 8-isoprostane expression in lung tissue. Eugenol and dehydrodieugenol B also inhibited the phosphorylation of Jc-Jun-NH2 terminal Kinase (JNK), a signaling protein involved in the MAPKinase pathway. There was no effect of these compounds in lung function. Therefore, eugenol and dehydrodieugenol B ameliorates several features of experimental ALI and could be considered as a pharmacological tool to ameliorate acute lung inflammation.

Tribulus terrestris L. Extract Protects against Lipopolysaccharide-Induced Inflammation in RAW 264.7 Macrophage and Zebrafish via Inhibition of Akt/MAPKs and NF-κB/iNOS-NO Signaling Pathways

Inflammation response is a regulated cellular process and excessive inflammation has been recognized in numerous diseases, such as cardiovascular disease, neurodegenerative disease, inflammatory bowel disease, and cancer. Tribulus terrestris L. (TT), also known as Bai Jili in Chinese, has been applied in traditional Chinese medicine for thousands of years while its anti-inflammatory activity and underlying mechanism are not fully elucidated. Here, we hypothesize Tribulus terrestris L. extract (BJL) which presents anti-inflammatory effect, and the action mechanism was also investigated. We employed the transgenic zebrafish line Tg(MPO:GFP), which expresses green fluorescence protein (GFP) in neutrophils, and mice macrophage RAW 264.7 cells as the in vivo and in vitro model to evaluate the anti-inflammatory effect of BJL, respectively. The production of nitric oxide (NO) was measured by Griess reagent. The mRNA expression levels of inflammatory cytokines and inducible nitric oxide synthase (iNOS) were measured by real-time PCR, and the intracellular total or phosphorylated protein levels of NF-κB, Akt, and MAPKs including MEK, ERK, p38, and JNK were detected by western blot. We found that BJL significantly inhibited fin transection or lipopolysaccharide- (LPS-) induced neutrophil migration and aggregation in zebrafish in vivo. In mice macrophage RAW 264.7 cells, BJL ameliorated LPS-triggered excessive release of NO and transcription of inflammatory cytokine genes including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). BJL also reduced the LPS-induced elevations of intracellular iNOS and nuclear factor kappa B (NF-κB) which mediate the cellular NO and inflammatory cytokine productions, respectively. Moreover, LPS dramatically increased the phosphorylation of Akt and MAPKs including MEK, ERK, p38, and JNK in RAW 264.7 cells, while cotreatment BJL with LPS suppressed their phosphorylation. Taken together, our data suggested that BJL presented potent anti-inflammatory effect and the underlying mechanism was closely related to the inhibition of Akt/MAPKs and NF-κB/iNOS-NO signaling pathways.

GC-MS Characterization of Antibacterial, Antioxidant, and Antitrypanosomal Activity of Syzygium aromaticum Essential Oil and Eugenol

Syzygium aromaticum has a diversity of biological activities due to the chemical compounds found in its plant products such as total phenolic compounds and flavonoids. The present work describes the chemical analysis and antimicrobial, antioxidant, and antitrypanosomal activity of the essential oil of S. aromaticum. Eugenol (53.23%) as the major compound was verified by gas chromatography-mass spectrometry. S. aromaticum essential oil was more effective against S. aureus (MIC 50 μg/mL) than eugenol (MIC 250 μg/mL). Eugenol presented higher antioxidant activity than S. aromaticum essential oil, with an EC₅₀ of 12.66 and 78.98 µg/mL, respectively. S. aromaticum essential oil and eugenol exhibited Trypanosoma cruzi inhibitory activity, with IC₅₀ of 28.68 ± 1.073 and 31.97 ± 1.061 μg/mL against epimastigotes and IC₅₀ of 64.51 ± 1.658 and 45.73 ± 1.252 μg/mL against intracellular amastigotes, respectively. Both compounds presented low cytotoxicity, with S. aromaticum essential oil displaying 15.5-fold greater selectivity for the parasite than the cells. Nitrite levels in T. cruzi-stimulated cells were reduced by essential oil (47.01%; p = 0.002) and eugenol (48.05%; p = 0.003) treatment. The trypanocidal activity of S. aromaticum essential oil showed that it is reasonable to use it in future research in the search for new therapeutic alternatives for trypanosomiasis.

Epigenetic immunomodulatory effect of eugenol and astaxanthin on doxorubicin cytotoxicity in hormonal positive breast Cancer cells

BACKGROUND

Hormonal receptor positive (HR+) breast cancer is the most commonly diagnosed molecular subtype of breast cancer; which showed good response to doxorubicin (DOX)-based chemotherapy. Eugenol (EUG) and astaxanthin (AST) are natural compounds with proved epigenetic and immunomodulatory effects in several cancer cell lines. This study has been initiated to investigate the molecular mechanism (s) whereby EUG and AST could enhance DOX cytotoxicity in MCF7 cells.

METHODS

Cytotoxic activity of DOX alone and combined with either 1 mM EUG or 40 μM AST was performed using sulphorhodamine-B assay in MCF7 cells. Global histones acetylation and some immunological markers were investigated using ELISA, western blotting and quantitative RT-PCR techniques. Functional assay of multidrug resistance was performed using rhodamine 123 and Hoechst 3342 dyes. Flow cytometry with annexin V and propidium iodide were used to assess the change in cell cycle and apoptosis along with the expression of some differentiation, apoptosis and autophagy proteins.

RESULTS

DOX alone resulted in concentration-dependent cytotoxicity with IC50 of 0.5 μM. Both EUG and AST significantly increased DOX cytotoxicity which is manifested as a significant decrease in DOX IC50 from 0.5 μM to 0.088 μM with EUG and to 0.06 μM with AST. Combinations of DOX with 1 mM EUG or 40 μM AST significantly increased the level of histones acetylation and histone acetyl transferase expression, while reduced the expression of aromatase and epidermal growth factor receptor (EGFR) when compared with 0.25 μM DOX alone. Also both combinations showed higher uptake of rhodamine but lower of Hoechst stains, along with increased the percentage of caspase 3, and decreased the expression of CK7 and LC3BI/II ratio. EUG combination induced IFγ but reduced TNFα causing shifting of cells from G2/M to S and G0/ G1 phases. Combination of DOX with EUG induced apoptosis through the higher BAX/ BCl2 ratio, while with AST was through the increase in caspase 8 expressions.

CONCLUSION

EUG and AST potentiated the anticancer activity of DOX through epigenetic histones acetylation along with the immunonomodulation of different apoptotic approaches in MCF7 cells.

Anterior gradient 2 is a novel pro-tumor factor in pancreatic cancer under NF-κB subunit RelA trans-regulation that can be suppressed by eugenic acid

This study aimed to examine eugenic acid (EA) as an alternative therapeutic approach against pancreatic cancer. The pancreatic cancer xenograft mouse model was employed to determine the impacts of treatment with EA on the growth of tumors. Expressions of NF-κB subunit RelA as well as Anterior gradient 2 (AGR2) were quantified in pancreatic cells treated with EA. Chromatin immunoprecipitation and luciferase report assay were performed to examine the regulation of AGR2 by RelA. The function of AGR2 as a downstream effector EA treatment was further assessed through overexpression of AGR2 in pancreatic cells. EA suppressed the growth of xenograft pancreatic tumor, and promoted the overall survival of animals with xenograft tumors. Furthermore, EA downregulated the expression of AGR2 in pancreatic cancer cells via the RelA binding site. Ectopic AGR2 overexpression attenuated the EA-elicited inhibition on the growth of xenograft pancreatic tumor, and negated the EA-induced enhancement of mouse survival. EA ameliorates pancreatic cancer through suppression of AGR2 expression, and future studies in clinical settings are needed to further assess the anti-cancer efficacy of EA.

Evaluation of Encapsulated Eugenol by Chitosan Nanoparticles on the aggressive model of rheumatoid arthritis

Chitosan Nanoparticles Eugenol recognizes as a potent antioxidant that can use the first therapeutic chemical to treat rheumatoid arthritis (RA) instead of Methotrexate. The purpose of this study was to investigate the effects of Chitosan Nanoparticles Eugenol as a potent Nano-herbal agent in the healing process of experimental neonatal RA compared to Methotrexate. The neonatal Wistar rats induced rheumatoid arthritis in both genders were divided into sham, control, the treatment receiving Methotrexate, and the second treatment receiving encapsulated Eugenol by Chitosan Nanoparticles groups. Afterward, Malondialdehyde, for assessment of lipid peroxidation as an oxidative stress biomarker by assay kit, FOXO3 protein as an antioxidant up-regulating by western blotting and expression of the TGF-β and CCL2/MCP-1 genes by real-time PCR evaluation, supported by a cartilage histopathology analysis. Based on these results, Methotrexate and Eugenol encapsulated by Chitosan Nanoparticles, a significant decrease is observed in the serum level of MDA and FOXO3 protein expression in comparison to the control group. Additionally, Nanoparticle herbal agent and Methotrexate has a decreasing effect on the expression of TGF-β and MCP-1 genes and a significant positive correlation was observed between MCP-1 and TGF-β. Inflammation, synovial hyperplasia, and pannus formation were extreme in the Collagen Induced Arthritis rats. It can be concluded that Encapsulated Eugenol by Chitosan Nanoparticles and Methotrexate, probably by dint of their immunomodulatory, anti-inflammatory, and antioxidant potential has a protective effect against RA. Nano Eugenol is capable of delivering promising lines results to treat autoimmune diseases such as RA can also be suggested.

Calcio-herbal formulation, Divya-Swasari-Ras, alleviates chronic inflammation and suppresses airway remodelling in mouse model of allergic asthma by modulating pro-inflammatory cytokine response

Asthma is a chronic allergic respiratory disease with limited therapeutic options. Here we validated the potential anti-inflammatory, anti-asthmatic and immunomodulatory therapeutic properties of calcio-herbal ayurvedic formulation, Divya-Swasari-Ras (DSR) in-vivo, using mouse model of ovalbumin (OVA) induced allergic asthma. HPLC analysis identified the presence of various bioactive indicating molecules and ICP-OES recognized the presence of Ca mineral in the DSR formulation. Here we show that DSR treatment significantly reduced cardinal features of allergic asthma including inflammatory cell accumulation, specifically lymphocytes and eosinophils in the Broncho-Alveolar Lavage (BAL) fluids, airway inflammation, airway remodelling, and pro-inflammatory molecules expression. Conversely, number of macrophages recoverable by BAL were increased upon DSR treatment. Histology analysis of mice lungs revealed that DSR attenuates inflammatory cell infiltration in lungs and thickening of bronchial epithelium. PAS staining confirmed the decrease in OVA-induced mucus secretion at the mucosal epithelium; and trichrome staining confirmed the decrease in peribronchial collagen deposition upon DSR treatment. DSR reduced the OVA-induced pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) levels in BALF and whole lung steady state mRNA levels (IL-4, -5, -33, IFN-γ, IL-6 and IL-1β). Biochemical assays for markers of oxidative stress and antioxidant defence mechanism confirmed that DSR increases the activity of SOD, Catalase, GPx, GSH, GSH/GSSG ratio and decreases the levels of MDA activity, GSSG, EPO and Nitrite levels in whole lungs. Collectively, present study suggests that, DSR effectively protects against allergic airway inflammation and possess potential therapeutic option for allergic asthma management.

The on-off action of Forkhead protein O3a in endotoxin tolerance of Kupffer cells depends on the PI3K/AKT pathway

BACKGROUND

The endotoxin tolerance (ET) of Kupffer cells (KCs) is an important protective mechanism for limiting endotoxin shock. As a key anti-inflammatory molecule, the roles and mechanism of Forkhead protein O3a (Foxo3a) in ET of KCs are not yet well understood.

METHODS

ET and nonendotoxin tolerance (NET) KCs models were established in vitro and in vivo. The levels of cytokines were detected by enzyme-linked immunosorbent assay (ELISA). The protein expression and phosphorylation levels were detected by western blotting (WB). Changes in the localization of nuclear factor kappa B (NF-κB) and Foxo3a in KCs were detected by immunofluorescence assays. KCs apoptosis and survival rates were detected by flow cytometry and an automatic cell counter, respectively.

RESULTS

The activity of NF-κB and the levels of p-Foxo3a and tumor necrosis factor (TNF-α) in the ET group were significantly lower than those in the NET group, while the levels of Foxo3a and interleukin 10 (IL-10) in the ET group were significantly higher than those in the NET group. Overexpression of Foxo3a or the use of a phosphatidylinositol-3-hydroxykinase (PI3K) inhibitor suppressed the activation of NF-κB by decreasing the levels of p-Foxo3a by inhibiting the activity of PI3K/AKT, which improved the tolerance of KCs and mice to endotoxin. In contrast, silencing Foxo3a or the use of a PI3K agonist reduced the tolerance of KCs and mice to endotoxin. The PI3K agonist counteracted the inhibitory effects of Foxo3a overexpression on NF-κB, impairing the tolerance of KCs to endotoxin.

CONCLUSIONS

The on-off action of Foxo3a in the ET of KCs depends on the PI3K/AKT pathway.

c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 is a critical regulator for arthritis progression by meditating inflammation in mice model

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. However, the pathogenesis of RA is not fully understood. Here, we reported that c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1, also known as JNK-interacting protein 3 (JIP3)) was significantly important for collagen-induced arthritis (CIA) in mice. Mice with JIP3 knockout (JIP3^-/-) showed a significant decrease in arthritis index and swollen joint count in CIA mice. The histopathology of spleen and joint was markedly alleviated by JIP3 deficiency in CIA mice. Excessive macrophage activation in CIA mice was also inhibited by JIP3 deletion. CIA-induced RANKL/RANK/OPG system mRNA expression was blocked in JIP3-knockout mice. In addition, CIA-triggered cytokine secretion and TLRs/NF-κB activation was inactivated by JIP3-deficiency. In line with the inhibition of inflammation by JIP3-knockout, it also significantly suppressed JNK pathway activation induced by CIA, as evidenced by the down-regulation of p-JNK, p-c-Jun, AFT-2 and Elk-1 in joints. In vitro, RANKL-exposed RAW264.7 cells showed a significant reduction of osteoclast formation using TRAP staining. Moreover, JIP3 inhibition reduced the RANKL-caused expression of osteoclastic genes and inflammatory regulators, as well as activation of TLRs/NF-κB and JNK signaling pathways. Importantly, we found that promoting JNK activity could abrogate JIP3 knockdown-suppressed osteoclastic genes expression, inflammatory response and NF-κB activation. These findings suggested that JIP3 could significantly impede osteoclast formation and function by regulating JNK activation, illustrating a novel therapeutic strategy for managing arthritis and preventing bone destruction.

Eugenol prevents fMLF-induced superoxide anion production in human neutrophils by inhibiting ERK1/2 signaling pathway and p47phox phosphorylation

Eugenol is a polyphenol extracted from Syzygium aromaticum essential oil. It is known to have anti-inflammatory and chemoprotective properties as well as a potent anti-oxidant activity due the presence of its phenolic group. In this study, we examined the effects of eugenol on neutrophil superoxide production, a key process involved in innate immunity and inflammation. Superoxide anion generationin human neutrophils was measured by cytochrome c reduction assay. Western blotting was used to analyze the phosphorylation of, p47phox, MAPKinases (p38 and ERK1/2), MEK1/2 and Raf, key proteins involved in the activation of NADPH oxidase. Pretreatment of neutrophils by increasing concentrations (2.5 µg/mL–20 µg/mL) of eugenol for 30 min, inhibited significantly (p < 0.001) superoxide anion generation induced by the chemotactic peptide formyl-Met-Leu-Phe (fMLF) with an IC50 of 5 µg/mL. Phorbolmyristate acetate (PMA)-stimulated O2⁻ production was affected only at the highest eugenol concentration (20 µg/mL). Results showed that eugenol decreased the phosphorylation of p47phox onSer-345 and Ser-328, the translocation of p47phox to the membranesand the phosphorylation of Raf, MEK1/2 and ERK1/2 proteins. Taken together, our results suggest that eugenol inhibits the generation of superoxide anion by neutrophils via the inhibition of Raf/MEK/ERK1/2/p47phox-phosphorylation pathway.

Structural characterization and anti-inflammatory potency of Mesobuthus martensii Karsch oligopeptides in lipopolysaccharide (LPS)-induced RAW264.7 macrophages

Scorpion venom represents a significant source of bio-active peptides. However, the anti-inflammatory potency of scorpion venom oligopeptides (CMOs) has not been well explored. In the current study, thirty-five CMOs were isolated, the amino acid sequences were identified, and the anti-inflammatory potency was further explored in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. The results showed that CMO-1 (His-Tyr-Gly-His) demonstrated the best anti-inflammatory potency by attenuating inflammatory cytokine (NO, TNF-α, IL-6, and IL-1β) production. CMO-1 also inhibited IκBα degradation and p65 nuclear translocation and suppressed NF-κB activation. Moreover, CMO-1 inhibited the phosphorylation of ERK, JNK, and p38 MAPKs. It is worth noting that CMO-1 exhibited anti-inflammatory potency; thus, it is a potential anti-inflammatory agent.

Scorpion venom represents a significant source of bio-active peptides.

An Overview on the Anti-inflammatory Potential and Antioxidant Profile of Eugenol

The bioactive compounds found in foods and medicinal plants are attractive molecules for the development of new drugs with action against several diseases, such as those associated with inflammatory processes, which are commonly related to oxidative stress. Many of these compounds have an appreciable inhibitory effect on oxidative stress and inflammatory response, and may contribute in a preventive way to improve the quality of life through the use of a diet rich in these compounds. Eugenol is a natural compound that has several pharmacological activities, action on the redox status, and applications in the food and pharmaceutical industry. Considering the importance of this compound, the present review discusses its anti-inflammatory and antioxidant properties, demonstrating its mechanisms of action and therapeutic potential for the treatment of inflammatory diseases.

Exogenous Heat Shock Cognate Protein 70 Suppresses LPS-Induced Inflammation by Down-Regulating NF-κB through MAPK and MMP-2/-9 Pathways in Macrophages

Heat shock cognate protein 70 (HSC70), a molecular chaperone, is constitutively expressed by mammalian cells to regulate various cellular functions. It is associated with many diseases and is a potential therapeutic target. Although HSC70 also possesses an anti-inflammatory action, the mechanism of this action remains unclear. This current study aimed to assess the anti-inflammatory effects of HSC70 in murine macrophages RAW 264.7 exposed to lipopolysaccharides (LPS) and to explain its pathways. Mouse macrophages (RAW 264.7) in 0.1 µg/mL LPS incubation were pretreated with recombinant HSC70 (rHSC70) and different assays (Griess assay, enzyme-linked immune assay/ELISA, electrophoretic mobility shift assay/EMSA, gelatin zymography, and Western blotting) were performed to determine whether rHSC70 blocks pro-inflammatory mediators. The findings showed that rHSC70 attenuated the nitric oxide (NO) generation, tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) expressions in LPS-stimulated RAW264.7 cells. In addition, rHSC70 preconditioning suppressed the activities and expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9. Finally, rHSC70 diminished the nuclear translocation of nuclear factor-κB (NF-κB) and reduced the phosphorylation of extracellular-signal regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPK), and phosphatidylinositol-3-kinase (PI3K/Akt). We demonstrate that rHSC70 preconditioning exerts its anti-inflammatory effects through NO production constriction; TNF-α, and IL-6 suppression following down-regulation of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and MMP-2/MMP-9. Accordingly, it ameliorated the signal transduction of MAPKs, Akt/IκBα, and NF-κB pathways. Therefore, extracellular HSC70 plays a critical role in the innate immunity modulation and mechanisms of endogenous protective stimulation.

Chronic diseases, inflammation, and spices: how are they linked?

Extensive research within the last several decades has revealed that the major risk factors for most chronic diseases are infections, obesity, alcohol, tobacco, radiation, environmental pollutants, and diet. It is now well established that these factors induce chronic diseases through induction of inflammation. However, inflammation could be either acute or chronic. Acute inflammation persists for a short duration and is the host defense against infections and allergens, whereas the chronic inflammation persists for a long time and leads to many chronic diseases including cancer, cardiovascular diseases, neurodegenerative diseases, respiratory diseases, etc. Numerous lines of evidence suggest that the aforementioned risk factors induced cancer through chronic inflammation. First, transcription factors NF-κB and STAT3 that regulate expression of inflammatory gene products, have been found to be constitutively active in most cancers; second, chronic inflammation such as pancreatitis, prostatitis, hepatitis etc. leads to cancers; third, activation of NF-κB and STAT3 leads to cancer cell proliferation, survival, invasion, angiogenesis and metastasis; fourth, activation of NF-κB and STAT3 leads to resistance to chemotherapy and radiation, and hypoxia and acidic conditions activate these transcription factors. Therefore, targeting these pathways may provide opportunities for both prevention and treatment of cancer and other chronic diseases. We will discuss in this review the potential of various dietary agents such as spices and its components in the suppression of inflammatory pathways and their roles in the prevention and therapy of cancer and other chronic diseases. In fact, epidemiological studies do indicate that cancer incidence in countries such as India where spices are consumed daily is much lower (94/100,000) than those where spices are not consumed such as United States (318/100,000), suggesting the potential role of spices in cancer prevention.

Gypenoside Protects Cardiomyocytes against Ischemia-Reperfusion Injury via the Inhibition of Mitogen-Activated Protein Kinase Mediated Nuclear Factor Kappa B Pathway In Vitro and In Vivo

Gypenoside (GP) is the major effective component of Gynostemma pentaphyllum and has been shown to encompass a variety of pharmacological activities. In this study, we investigated whether GP is able to protect cardiomyocytes against injury myocardial ischemia-reperfusion (I/R) injury by using in vitro oxygen-glucose deprivation-reoxygenation (OGD/R) H9c2 cell model and in vivo myocardial I/R rat model. We found that GP pre-treatment alleviated the impairments on the cardiac structure and function in I/R injured rats. Moreover, pre-treatment with GP significantly inhibited IκB-α phosphorylation and nuclear factor (NF)-κB p65 subunit translocation into nuclei. GP and the MAPK pathway inhibitors also reduced the phosphorylation of ERK, JNK, and p38 in vitro. Specific inhibition of ERK, JNK, and p38 increased the cell viability of OGD/R injured cells. Taken together, our data demonstrated that GP protects cardiomyocytes against I/R injury by inhibiting NF-κB p65 activation via the MAPK signaling pathway both in vitro and in vivo. These findings suggest that GP may be a promising agent for the prevention or treatment of myocardial I/R injury.

Pretreatment of human cerebrovascular endothelial cells with CO-releasing molecule-3 interferes with JNK/AP-1 signaling and suppresses LPS-induced proadhesive phenotype

OBJECTIVE

Exogenously administered CO interferes with PMN recruitment to the inflamed organs. The mechanisms of CO-dependent modulation of vascular proadhesive phenotype, a key step in PMN recruitment, are unclear.

METHODS

We assessed the effects/mechanisms of CO liberated from a water-soluble CORM-3 on modulation of the proadhesive phenotype in hCMEC/D3 in an in vitro model of endotoxemia. To this end, hCMEC/D3 were stimulated with LPS (1 μg/mL) for six hours. In some experiments hCMEC/D3 were pretreated with CORM-3 (200 μmol/L) before LPS-stimulation. PMN rolling/adhesion to hCMEC/D3 were assessed under conditions of laminar shear stress (0.7 dyn/cm(2) ). In parallel, expression of adhesion molecules E-selectin, ICAM-1, and VCAM-1 (qPCR), activation of transcription factors, NF-κB and AP-1 (ELISA), and MAPK-signaling (expression/phosphorylation of p38, ERK1/2, and JNK1/2; western blot) were assessed.

RESULTS

The obtained results indicate that CORM-3 pretreatment reduces PMN rolling/adhesion to LPS-stimulated hCMEC/D3 (p < 0.05). Decreased PMN rolling/adhesion to hCMEC/D3 was associated with CORM-3-dependent inhibition of MAPK JNK1/2 activation (Tyr-phosphorylation), inhibition of transcription factor, AP-1 (c-Jun phosphorylation), and subsequent suppression of VCAM-1 expression (p < 0.05).

CONCLUSIONS

These findings indicate that CORM-3 pretreatment interferes with JNK/AP-1 signaling and suppresses LPS-induced upregulation of the proadhesive phenotype in hCMEC/D3.

Inhibitory effects of eugenol on RANKL-induced osteoclast formation via attenuation of NF-κB and MAPK pathways

Bone loss diseases are often associated with increased receptor activator of NF-κB ligand (RANKL)-induced osteoclast formation. Compounds that can attenuate RANKL-mediated osteoclast formation are of great biomedical interest. Eugenol, a phenolic constituent of clove oil possesses medicinal properties; however, its anti-osteoclastogenic potential is unexplored hitherto. Here, we found that eugenol dose-dependently inhibited the RANKL-induced multinucleated osteoclast formation and TRAP activity in RAW264.7 macrophages. The underlying molecular mechanisms included the attenuation of RANKL-mediated degradation of IκBα and subsequent activation of NF-κB pathway. Furthermore, increase in phosphorylation and activation of RANKL-induced mitogen-activated protein kinase pathways (MAPK) was perturbed by eugenol. RANKL-induced expression of osteoclast-specific marker genes such as TRAP, cathepsin K (CtsK) and matrix metalloproteinase-9 (MMP-9) was remarkably downregulated by eugenol. These findings provide the first line of evidence that eugenol mediated attenuation of RANKL-induced NF-κB and MAPK pathways could synergistically contribute to the inhibition of osteoclast formation. Eugenol could be developed as therapeutic agent against diseases with excessive osteoclast activity.

Chrysanthemum boreale flower floral water inhibits platelet-derived growth factor-stimulated migration and proliferation in vascular smooth muscle cells

CONTEXT

Chrysanthemum boreale Makino (Compositae) (CBM) is a traditional medicine that has been used for the prevention or treatment of various disorders; it has various properties including antioxidation, anti-inflammation, and antitumor.

OBJECTIVE

The present study was designed to explore the in vitro effect of CBM flower floral water (CBMFF) on atherosclerosis-related responses in rat aortic smooth muscle cells (RASMCs).

MATERIALS AND METHODS

CBMFF was extracted from CBM flower by steam distillation and analyzed using gas chromatography-mass spectrometry. The anti-atherosclerosis activity of CBMFF was tested by estimating platelet-derived growth factor (PDGF)-BB (10 ng/mL)-induced proliferation and migration levels and intracellular kinase pathways in RASMCs at CBMFF concentrations of 0.01-100 μM and analyzing ex vivo aortic ring assay.

RESULTS

Gas chromatography-mass spectrometry showed that the CBMFF contained a total of seven components. The CBMFF inhibits PDGF-BB-stimulated RASMC migration and proliferation (IC50: 0.010 μg/mL). Treatment of RASMCs with PDGF-BB induced PDGFR-β phosphorylation and increased the phosphorylations of MAPK p38 and ERK1/2. CBMFF addition prevented PDGF-BB-induced phosphorylation of these kinases (IC50: 008 and 0.018 μg/mL, for p38 MAPK and ERK1/2, respectively), as well as PDGFR-β (IC50: 0.046 μg/mL). Treatment with inhibitors of PDGFR, P38 MAPK, and ERK1/2 decreased PDGF-BB-increased migration and proliferation in RASMCs. Moreover, the CBMFF suppressed PDGF-BB-increased sprout outgrowth of aortic rings (IC50: 0.047 μg/mL).

DISCUSSION AND CONCLUSION

These results demonstrate that CBMFF may inhibit PDGF-BB-induced vascular migration and proliferation, most likely through inhibition of the PDGFR-β-mediated MAPK pathway; therefore, the CBMFF may be promising candidate for the development of herbal remedies for vascular disorders.

Geniposide suppresses LPS-induced nitric oxide, PGE2 and inflammatory cytokine by downregulating NF-κB, MAPK and AP-1 signaling pathways in macrophages

Inflammatory responses are important to host immune reactions, but uncontrolled inflammatory mediators may aid in the pathogenesis of other inflammatory diseases. Geniposide, an iridoid glycoside found in the herb gardenia, is believed to have broad-spectrum anti-inflammatory effects in murine models but its mechanism of action is unclear. We investigated the action of this compound in murine macrophages stimulated by lipopolysaccharide (LPS), as the stimulation of macrophages by LPS is known to induce inflammatory reactions. We determined the effect of geniposide on LPS-induced production of the inflammatory mediators, nitric oxide (NO) and prostaglandin E2 (PGE2), the mRNA and protein expression of the NO and PGE2 synthases, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively, and the mRNA and protein expression of the inflammatory cytokine, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Furthermore, nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK) and activator protein (AP)-1 activity were assayed. To understand the action of geniposide on the NF-κB and MAPK pathways, we studied the effect of NF-κB and MAPK inhibitors on the LPS-induced production of NO, PGE2 and TNF-α. Our findings clearly showed that geniposide mainly exerts its anti-inflammatory effects by inhibiting the LPS-induced NF-κB, MAPK and AP-1 signaling pathways in macrophages, which subsequently reduces overexpression of the inducible enzymes iNOS and COX-2 and suppresses the expression and release of the inflammatory factors, TNF-α, IL-6, NO and PGE2. Thus, geniposide shows promise as a therapeutic agent in inflammatory diseases.

Targeting JNK by a new curcumin analog to inhibit NF-kB-mediated expression of cell adhesion molecules attenuates renal macrophage infiltration and injury in diabetic mice

Macrophage infiltration contributes to the pathogenesis of diabetic renal injury. However, the regulatory mechanisms between macrophage infiltration and epithelial cell activation are still unclear. Our previous study found that C66, a novel curcumin analog, was able to inhibit inflammatory cytokine expression in vitro and in vivo. This study further elucidated whether C66 can prevent glucose-induced renal epithelial activation and inflammatory macrophage infiltration by a MAPK/NF-κB medicated mechanism. Our data show that pretreatment with C66 not only significantly reduced high glucose (HG)-induced over-expressions of VCAM-1, ICAM-1 and MCP-1, but also remarkably inhibited NF-κB activation, MAPKs phosphorylation, and subsequently macrophage adhesion in renal epithelial NRK-52E cells. Furthermore, we find that MAPKs, especially JNK, play important roles in HG-induced NF-κB activation, which regulates the over-expression of adhesion molecules in HG-stimulated NRK-52E cells. A molecular docking predicted that C66 may target JNK2, which leads to its anti-inflammatory actions. In vivo, administration of C66 or JNK special inhibitor SP600125 at 5 mg/kg markedly decreased diabetes-induced renal adhesion molecule expression, NF-κB activation, inflammatory cell infiltration, and pathological indexes in the kidneys of diabetic mice. These findings provide a perspective on the renoprotective effects of C66 in diabetes, and outline a novel therapeutic strategy of JNK inhibition for the treatment of diabetic nephropathy.

Induction of matrix metalloproteinase-2 and -9 via Erk1/2-NF-κB pathway in human astroglia infected with Toxoplasma gondii

Matrix metalloproteinase (MMP)-2 and MMP-9 can cleave fibronectin, allowing leukocyte migration to the site of Toxoplasma gondii infection during toxoplasmic encephalitis. The aim of this study was to investigate the association between extracellular signal-regulated kinase (Erk)1/2-nuclear factor (NF)-κB pathway and MMP-2/-9 expression in astroglia infected with T. gondii tachyzoite in vitro. Our results showed that phosphorylated (p)-Erk1/2 transiently increased 1h post-infection (PI) and p-NF-κB significantly increased from 1h PI to 12h PI in cell homogenates. NF-κB was bound directly to oligonucleotides containing putative NF-κB binding sites for the MMP-9 promoter. Additionally, expression of p-NF-κB, MMP-2, and MMP-9 was significantly decreased by MG132, an indirect NF-κB inhibitor. Treatment with PD98059, an Erk kinase inhibitor, efficiently reduced p-Erk1/2, p-NF-κB, MMP-2, and MMP-9 expression. These results suggest that suppression of the Erk1/2-NF-κB signaling pathway causes reductions in MMP-2 and MMP-9 activities in astroglia response to T. gondii infection. Thus, inhibiting this signaling intermediate involved in MMP-2 and MMP-9 expression may be a potential method for controlling inflammatory development of T. gondii-induced encephalitis.

Up-regulation of matrix metalloproteinases-2 and -9 via an Erk1/2/NF-κB pathway in murine mast cells infected with Toxoplasma gondii

Mast cells are key effectors in inflammation and contain proteinases that are released on activation. This study investigates associations between extracellular signal-regulated kinase (Erk)1/2, nuclear factor (NF)-κB, matrix metalloproteinase (MMP)-2 and MMP-9 in mast cells infected with Toxoplasma gondii tachyzoites. T. gondii infection led to increased mast cell degranulation. Phosphorylated (p)-Erk1/2 and p-NF-κB were increased significantly in mast cells infected with T. gondii. Pretreatment with the Erk kinase inhibitor PD98059 significantly decreased the expression of p-Erk1/2, p-NF-κB, MMP-2 and MMP-9. Treatment with MG132, an indirect NF-κB inhibitor, effectively reduced p-IκBα, p-NF-κB, MMP-2 and MMP-9 expression. Collectively, these data show that suppression of an Erk1/2/NF-κB signalling pathway caused a reduction in MMP-2 and -9 activities. Inhibiting this signalling pathway for MMP-2 and MMP-9 expression might offer a potential way to control early T. gondii infection. This pathway for the generation of MMP-2 and MMP-9 is important for mast cell secretion and the NF-κB/Erk1/2 signalling pathway may be key in MMP-2 and MMP-9 production in host defense against toxoplasmosis.

IL-36 Receptor Antagonist with Special Emphasis on IL-38

IL-36 is another family member of IL-1 and induces the production of proinflammatory cytokines and activates MAPK and NFκB pathways. IL-36 is a common mediator of innate and adaptive immune response and is inhibited by IL-36 receptor antagonist (RA). IL-36RA acts on IL-36 receptor ligand which exerts proinflammatory effect in vivo and in vitro. IL-38 binds to IL-36 receptor as does IL-36RA and has similar biological effects on immune cells. IL-38 is also a member of IL-1 cytokine and shares some characteristics of IL-1RA, binding the same IL-1 receptor type I. IL-38 plays a role in the pathogenesis of inflammatory diseases, exerting protective effect in some autoimmune diseases. Both IL-38 and IL-36RA have an anti-inflammatory biological effect, however in some cases have contrary effects.

Drug screening for autophagy inhibitors based on the dissociation of Beclin1-Bcl2 complex using BiFC technique and mechanism of eugenol on anti-influenza A virus activity

Autophagy is involved in many human diseases, such as cancer, cardiovascular disease and virus infection, including human immunodeficiency virus (HIV), hepatitis C virus (HCV), influenza A virus (IAV) and coxsackievirus B3/B4 (CVB3/B4), so a drug screening model targeting autophagy may be very useful for the therapy of these diseases. In our study, we established a drug screening model based on the inhibition of the dissociation of Beclin1-Bcl2 heterodimer, an important negative regulator of autophagy, using bimolecular fluorescence complementation (BiFC) technique for developing novel autophagy inhibitors and anti-IAV agents. From 86 examples of traditional Chinese medicines, we found Syzygium aromaticum L. had the best activity. We then determined the anti-autophagy and anti-IAV activity of eugenol, the major active compound of Syzygium aromaticum L., and explored its mechanism of action. Eugenol could inhibit autophagy and IAV replication, inhibited the activation of ERK, p38MAPK and IKK/NF-κB signal pathways and antagonized the effects of the activators of these pathways. Eugenol also ameliorated the oxidative stress and inhibited the expressions of autophagic genes. We speculated that the mechanism underlying might be that eugenol inhibited the oxidative stress and the activation of ERK1/2, p38MAPK and IKK/NF-κB pathways, subsequently inhibited the dissociation of Beclin1-Bcl2 heterodimer and autophagy, and finally impaired IAV replication. These results might conversely display the reasonableness of the design of our screening model. In conclusion, we have established a drug screening model for developing novel autophagy inhibitor, and find eugenol as a promising inhibitor for autophagy and IAV infection.

Impact and Neuropeptide Substance Pan Inflammatory Compound on Arachidonic Acid Compound Generation

There is much evidence that neuropeptide substance P is involved in neurogenic inflammation and is an important neurotransmitter and neurmodulator compound. In addition, substance P plays an important role in inflammation and immunity. Macrophages can be activated by substance P which provokes the release of inflammatory compounds such as interleukins, chemokines and growth factors. Substance P is involved in the mechanism of pain through the trigeminal nerve which runs through the head, temporal and sinus cavity. Substance P also activates mast cells to release inflammatory mediators such as arachindonic acid compound, cytokines/chemokines and histamine. The release of these chemical mediators is crucial for inflammatory response. Among these mediators there are prostoglandins and leukotrines. Here we review the impact of substance P on inflammatory compounds.