Esculentoside B inhibits inflammatory response through JNK and downstream NF-κB signaling pathway in LPS-triggered murine macrophage RAW 264.7 cells

Metabolic exploration of the developmental abnormalities and neurotoxicity of Esculentoside B, the main toxic factor in Phytolaccae radix

P: radix is a perennial herb, and its extracts have various biological properties that make it a potential candidate for the treatment of tumors, edema, and lymphatic stasis. However, the main factor contributing to its toxicity are not clear. Here, we used a zebrafish toxicological model to study the main toxicity factor of P. radix and explore the potential mechanisms involved. The results revealed that Esculentoside B was the major toxic factor of P. radix. Exposure of zebrafish larvae to Esculentoside B caused developmental abnormalities, neurotoxicity and altered locomotor behavior. The combination of AChE activity and the expression levels of genes relevant to CNS development demonstrated that Esculentoside B is neurotoxic to zebrafish larvae, impairs their CNS development, and that AChE may be a toxic target of Esculentoside B. Metabolomic analysis has revealed that Esculentoside B exposure can disrupt D-Amino acid metabolism, protein export, autophagy, and mTOR signaling pathways in zebrafish larvae. These findings provide insights into the molecular mechanisms underlying EsB-induced neurotoxicity in zebrafish, which can facilitate further research and development of P. radix for safe consumption.

Fast and efficient identification of hyaluronidase specific inhibitors from Chrysanthemum morifolium Ramat. using UF-LC-MS technique and their anti-inflammation effect in macrophages

The purpose of the study was to establish a rapid analytical strategy to screen potential anti-inflammatory compounds from Flos Chrysanthemum flower. The enzyme assay was conducted to prescreen botanical extracts, in which Chrysanthemum morifolium aqueous extract (CME) displayed hyaluronidase (HAase) inhibitory activity in a dose-dependent manner with the values of 8.31, 24.25, and 66.51% at concentrations of 1.00, 2.00, and 4 0.00 mg/mL, respectively. Eight potential compounds targeting HAase (compounds 9, 10, 11, 13, 15, 17, 20 and 21) from CME were screened using ultrafiltration affinity liquid chromatography coupled with mass spectrometry (UF-LC-MS) technology. The well-known inhibitor, dipotassium glycyrrhizinate (DG), was used as a positive control and competitive ligand to eliminate false positives. Then, four of these potential components (compounds 9, 10, 17, and 21), namely eriodictyol-7-O-glucoside, luteoloside, apigenin-7-O-glucoside and diosmetin-7-O-glucoside, were distinguished as potent HAase specific inhibitor candidates with high BD and CBD values. The enzyme inhibitory activities of candidate compounds were verified using enzyme inhibition assay. At a concentration of 1000 μM, compounds 9, 10, 17, and 21 showed 40.15, 44.85, 18.04, and 24.15% inhibition of HAase, respectively. Furthermore, all the four compounds significantly decreased the production of nitric oxide (NO) and IL-6, and significantly suppressed the mRNA expression of inducible NO synthase (iNOS) and IL-1β in both murine and human macrophages.

Anti-inflammatory chemical constituents of Flos Chrysanthemi Indici determined by UPLC-MS/MS integrated with network pharmacology

Flos Chrysanthemi Indici (FCI), the flower of Chrysanthemum indicum L., is a common functional food and a well-known traditional Chinese medicine (TCM) for the treatment of inflammatory diseases. Previous studies have revealed that FCI has anti-inflammatory activity, but little is known about its anti-inflammatory chemical profile. In this study, the potential anti-inflammatory constituents of FCI were investigated by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with the network pharmacology approach, and further confirmed on a LPS activated RAW264.7 macrophage model. As a result, a total of forty-two compounds, including thirty-two flavonoids, nine phenolic acids and one sesquiterpene, were identified. Among them, fourteen compounds including eight flavonoids (11, 17, 24, 28, 32, 39, 41 and 42) and six caffeoylquinic acids (3, 4, 5, 13, 15 and 20) were recognized as potential key anti-inflammatory constituents of FCI through network pharmacology analysis, because they accounted for 92% of the relative peak area in the UPLC-Q-TOF/MS chromatogram and acted on 87 of 97 the inflammatory targets of FCI. However, only 16 targets were shared between the flavonoids and caffeoylquinic acids, indicative of both acting on more different targets. Further the anti-inflammatory effects of the fourteen constituents were validated with the decreased levels of NO, TNF-α, IL-6 and PGE2 in RAW264.7 macrophage cells treated with LPS. Our results indicated that both flavonoids and caffeoylquinic acids were responsible for the anti-inflammatory effect of FCI through synergetic actions on multi-targets. Moreover, 3,5-dicaffeoylquinic acid (15), luteolin (24) and linarin (28) were the most important active constituents of FCI and could be selected as chemical markers for quality control of FCI. Overall, the findings not only explore the anti-inflammatory chemical constituents of FCI, but also provide novel insights into the effective constituents and mechanism of TCMs.

Esculentosides: Insights into the potential health benefits, mechanisms of action and molecular targets

BACKGROUND

Esculentosides and related phytolaccosides form a group of oleanene-type saponins isolated from plants of the Phytolaccaceae family, essentially Phytolacca esculenta, P. americana and P. acinosa. This chemical family offers a diversity of glycosylated compounds, including molecules with a mono-, di- or tri-saccharide unit at position C-3, and with or without a glucose residue at position C-28. The esculentosides, which derive essentially from the sapogenin jaligonic acid or its 30-methyl ester phytolaccagenin, exhibit anti-inflammatory, antifungal and anticancer activities.

PURPOSE

The objective of the review was to identify the 26 esculentosides (ES) and phytolaccosides known to date, including 16 monodesmosidic and 10 bidesmosidic saponins, and to review their pharmacological properties and molecular targets.

METHODOLOGY

The retrieval of potentially relevant studies was done by systematically searching of scientific databases like Google Scholar and PubMed in January-May 2020. The main keywords used as search terms were related to esculentosides, phytolaccosides and Phytolaccaceae. The systematic search retrieved about 110 papers that were potentially relevant and after an abstract-based selection, 68 studies were analyzed in details and discussed.

RESULTS

The structural relationship between the compounds and their sapogenin precursors has been studied. In addition, the pharmacological properties of the main ES, such as ES-A, -B and -H, have been analyzed to highlight their mode of action and potential targets. ES-A is a potent inhibitor of the release of cytokines and this anti-inflammatory activity contributes to the anticancer effects observed in vitro and in vivo. Potential molecular targets of ES-A/B include the enzymes cyclooxygenase 2 (COX-2) and casein kinase 2 (CK2). In addition, the targeting of the protein high-mobility group box 1 (HGMB1) by ES-A/B is proposed, based on molecular modeling and the structural analogy with the related saponin glycyrrhizin, a potent HGMB1 alarmin inhibitor.

CONCLUSION

More work is needed to properly characterize the molecular targets but otherwise compounds like ES-A and ES-H emerge as potent anti-inflammatory and anticancer agents and ES-B as an antifungal agent. A preclinical development of these three compounds should be considered.

In vitro and in vivo anti-inflammatory effects of different extracts from Epigynum auritum through down-regulation of NF-κB and MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Epigynum auritum has been historically used as a "dai" or traditional medicine for the treatment of inflammation, swelling and severe pain during injury; these may reduce risk of disease and lead to healthier aging. Apart from this, Epigynum auritum extract was also used in arhritis treatment which is also a type of inflammation. Previous phytochemical studies of E. auritum revealed that steroids are main characteristic components with a number of biological activities (especially immunosuppressive and anti-inflammatory activity) Nevertheless, the underlying mechanism of the E. auritum on inflammatory diseases is still unresolved.

AIM OF THE STUDY

This study aimed to comparatively investigate the anti-inflammatory potential of different fractions from the extract of E. auritum (EAE), with their possible active ingredients to reveal the underlying mechanism.

MATERIALS AND METHODS

The EAE was fractionated by column chromatography with macroporous resin D101 which yielded six fractions. The potential anti-inflammatory properties of different fractions of EAE were evaluated in in vitro and in vivo model. The lipopolysaccharide (LPS)-induced RAW264.7 macrophages cells were used for in vitro studies however two typical acute inflammation murine models (xylene-induced ear edema and carrageenan-induced paw edema) were used for anti-inflammatory studies. The important molecular mechanisms related to inflammation were also analyzed by ELISA, western blotting and immunofluorescence. UHPLC-MS/MS was used to analyze the chemical composition of 100% EAE fraction.

RESULTS

Different EAE fractions (especially the Fr. 100% of MeOH:H₂O) significantly reduced the productions of NO, ROS, TNF-α, and IL-6 by LPS-induced RAW264.7 macrophages and increased the expression of IL-10. The expression levels of iNOS and COX-2 enzymes were significantly down-regulated by 100% EAE fraction. Furthermore, 100% EAE fraction inhibited the phosphorylation of the ERK1/2, JNK, and p38 MAPK, and reduced the nuclear translocation of NF-κB which prevents its activation by blocking the phosphorylation and degradation of inhibitor protein of IκBα. In addition two inflammatory animal models; xylene-induced ear edema and carrageenan-stimulated paw edema were also developed with significantly ameliorated inflammatory cytokines. The treatment of these inflammatory models with 100% EAE fraction (Fr. 100%) suppressed the expressions of elevated inflammatory cytokines. Besides the UHPLC-HRMS/MS analysis was also carried out in which the androstane analogues were found to be as a main chemical components.

CONCLUSION

Different fractions (especially Fr. 100%) exert inhibitory effect on inflammation by regulating the release of inflammatory mediators through the NF-κB and MAPK signaling pathways. The androstane and its derivatives might be performing an important role in the observed anti-inflammatory activity. Therefore, Fr. 100% of EAE could be applied as a potential drug candidate for the prevention and treatment of inflammatory diseases.

Octominin Inhibits LPS-Induced Chemokine and Pro-inflammatory Cytokine Secretion from RAW 264.7 Macrophages via Blocking TLRs/NF-κB Signal Transduction

Inflammation is a well-organized innate immune response that plays an important role during the pathogen attacks and mechanical injuries. The Toll-like receptors (TLR)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a major signal transduction pathway observed in RAW 264.7 macrophages during the inflammatory responses. Here, we investigated the anti-inflammatory effects of Octominin; a bio-active peptide developed from Octopus minor in RAW 264.7 macrophages in vitro. Octominin was found to inhibit lipopolysaccharides (LPS)-stimulated transcriptional activation of NF-κB in RAW 264.7 cells and dose-dependently decreased the mRNA expression levels of TLR4. Specifically, in silico docking results demonstrated that Octominin has a potential to inhibit TLR4 mediated inflammatory responses via blocking formation of TLR4/MD-2/LPS complex. We also demonstrated that Octominin could significantly inhibit LPS-induced secretion of pro-inflammatory cytokine (interleukin-β; IL-1β, IL-6, and tumor necrosis factor-α) and chemokines (CCL3, CCL4, CCL5, and CXCL10) from RAW 264.7 cells. Additionally, Octominin repressed the LPS-induced pro-inflammatory mediators including nitric oxide (NO), prostaglandin E2, inducible NO synthase, and cyclooxygenase 2 in macrophages. These results suggest that Octominin is a potential inhibitor of TLRs/NF-κB signal transduction pathway and is a potential candidate for the treatment of inflammatory diseases.

Anti-inflammatory properties of the marine plant Posidonia oceanica (L.) Delile

ETHNOPHARMACOLOGICAL RELEVANCE

Posidonia oceanica (L.) Delile is an endemic seagrass of the Mediterranean Sea whose use has been documented as a traditional herbal remedy for diabetes and hypertension. Our recently described Posidonia oceanica leaves extract is a phytocomplex endowed with interesting bioactivities, including the inibitory property on human cancer cell migration.

AIM OF THE STUDY

The aim of this study was to investigate the anti-inflammatory effects of P. oceanica extract underlying its mechanism of action.

MATERIALS AND METHODS

We explored the anti-inflammatory effects of P. oceanica extract on RAW264.7 murine macrophages activated by LPS. We investigated the reactive oxygen species (ROS) and nitric oxide (NO) production and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Then, we examined P. oceanica extract role on the regulation of NF-κB signaling pathway.

RESULTS

P. oceanica phytocomplex exhibited a strong ability to inhibit oxidative stress by affecting the production of both ROS and NO and to reduce iNOS and COX-2 levels. In addition, it was evidenced its anti-inflammatory role via inhibiting NF-κB signaling pathway through modulation of ERK1/2 and Akt intracellular cascades.

CONCLUSIONS

Our results recognize an anti-inflammatory role of P. oceanica phytocomplex particularly emphasizing its cell safe mechanism of action. In conclusion, the marine plant P. oceanica may be of great interest for scientific research as a source of promising molecules for designing alternative strategies to the conventional treatment of inflammatory diseases.