Semisynthesis and Inhibitory Effects of Solidagenone Derivatives on TLR-Mediated Inflammatory Responses.

A series of nine derivatives (2⁻10) were prepared from the diterpene solidagenone (1) and their structures were elucidated by means of spectroscopic studies. Their ability to inhibit inflammatory responses elicited in peritoneal macrophages by TLR ligands was investigated. Compounds 5 and 6 showed significant anti-inflammatory effects, as they inhibited the protein expression of nitric oxide synthase (NOS-2), cyclooxygenase-2 (COX-2), and cytokine production (TNF-α, IL-6, and IL-12) induced by the ligand of TLR4, lipopolysaccharide (LPS), acting at the transcriptional level. Some structure⁻activity relationships were outlined. Compound 5 was selected as a representative compound and molecular mechanisms involved in its biological activity were investigated. Inhibition of NF-κB and p38 signaling seems to be involved in the mechanism of action of compound 5. In addition, this compound also inhibited inflammatory responses mediated by ligands of TLR2 and TLR3 receptors. To rationalize the obtained results, molecular docking and molecular dynamic studies were carried out on TLR4. All these data indicate that solidagenone derivative 5 might be used for the design of new anti-inflammatory agents.

Solidagenone from Solidago chilensis Meyen Protects against Acute Peritonitis and Lipopolysaccharide-Induced Shock by Regulating NF-κB Signaling Pathway.

Anti-inflammatory agents are widely used for the treatment of inflammatory diseases. Nevertheless, the associated side effects of the available drugs make it necessary to search for new anti-inflammatory drugs. Here, we investigated the anti-inflammatory activity of solidagenone. Initially, we observed that a single dose of 30, 60, or 90 mg/kg of solidagenone did not result in mortality or elicit any discernible signs of toxicity in mice. At the same doses, solidagenone promoted a significant reduction in the migration of neutrophils in an acute peritonitis model and decreased mortality in a lipopolysaccharide-induced endotoxic shock model. Interestingly, treatment with solidagenone conferred a protective effect against leukopenia and thrombocytopenia, hematological disorders commonly observed in sepsis conditions. In addition, treatment with all the doses of solidagenone promoted a significant reduction in nitric oxide, TNF-α, and IL-1ß levels relative to the LPS-stimulated vehicle-treated cultures. Furthermore, gene expression and in silico analyses also supported the modulation of the NF-κB pathway by solidagenone. Finally, in silico pharmacokinetics predictions indicated a favorable drugability profile for solidagenone. Taken together, the findings of the present investigation show that solidagenone exhibits significant anti-inflammatory properties in acute experimental models, potentially through the modulation of the NF-κB signaling pathway.

Solidagenone in vivo leishmanicidal activity acting in tissue repair response, and immunomodulatory capacity in Leishmania amazonensis.

Leishmaniasis is a group of chronic parasitic diseases in humans caused by species of the Leishmania genus. Current treatments have high toxicity, cost, duration, limited effectiveness, significantly complex administration, and drug-resistant strains. These factors highlight the importance of research into new therapies that use drugs without toxic effects. Solidagenone (SOL), the main labdane diterpene isolated from the plant Solidago chilensis, has anti-inflammatory, gastroprotective, antioxidant, tissue repair-inducing effects, suggesting a role in novel drug development. This study investigates in vivo mechanism action of SOL treatment in L. amazonensis-infected BALB/c mice. SOL was isolated from the roots of S. chilensis, and L. amazonensis-infected mice were treated daily with SOL (10, 50, 100 mg/kg) by gavage for 30 days. Gastric (NAG, MPO), hepatic (AST, ALT), systemic (body weight, NO) toxicity, leishmanicidal activity (lesion size, parasite burden), cell profile (macrophage, neutrophil infiltration), antioxidant (ABTS, NBT, NO), oxidant parameters (FRAP, ABTS), Th1, Th2, Th17 cytokines (CBA), collagen deposition (picrosirius), arginase, iNOS, NF-kB, and NRF2 (immunofluorescence) were evaluated. In vivo results showed SOL-treatment did not induce gastric, hepatic, or systemic toxicity in L. amazonensis-infected mice. SOL was able to reduce the lesion size and parasite load at the site of infection, increasing macrophage infiltration and neutrophil migration, exerting a balance in antioxidant (increased ABTS, NBT reduction, and NO), oxidative (increased FRAP and ABTS), and anti-inflammatory responses (reduced TNF-α, IFN-γ and increased IL-6, IL-17 production), and inducing arginase, iNOS, NF-kB, NRF2 and collagen deposition (type III), favoring wound healing and accelerating tissue repair at the site injury.

The protective effect of solidagenone from Solidago chilensis Meyen in a mouse model of airway inflammation.

Solidagenone is the main active constituent present in Solidago chilensis Meyen which is used in folk medicine to treat pain and inflammatory diseases. This study aimed to evaluate the anti-inflammatory activity of solidagenone in vitro and in a model of allergic airway inflammation. In vitro studies were performed in activated macrophages and lymphocytes. BALB/c mice were sensitized and challenged with ovalbumin and treated with solidagenone orally (30 or 90 mg/kg body weight) or dexamethasone, as a positive control in our in vivo analysis. Supernatant concentrations of nitrite, TNF and IL-1ß, as well as gene expression of pro-inflammatory mediators in macrophages cultures, were reduced after solidagenone treatment, without affecting macrophages viability. Besides, solidagenone significantly decreased T cell proliferation and secretion of IFNγ and IL-2. Th2 cytokine concentrations and inflammatory cell counts, especially eosinophils, in bronchoalveolar lavage fluid were reduced in mice treated with solidagenone. Histopathological evaluation of lung tissue was performed, and morphometrical analyses demonstrated reduction of cellular infiltration and mucus hypersecretion. Altogether, solidagenone presented anti-inflammatory activity in vitro and in vivo in the OVA-induced airway inflammation model, suggesting its promising pharmacological use as an anti-inflammatory agent for allergic hypersensitivity.

Solidagenone acts on promastigotes of L. amazonensis by inducing apoptosis-like processes on intracellular amastigotes by IL-12p70/ROS/NO pathway activation.

BACKGROUND: Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the Leishmania genus. Currently, the treatment has limited effectiveness and high toxicity, is expensive, requires long-term treatment, induces significant side effects, and promotes drug resistance. Thus, new therapeutic strategies must be developed to find alternative compounds with high efficiency and low cost. Solidagenone (SOL), one of the main constituents of Solidago chilensis, has shown gastroprotective, anti-inflammatory and immunomodulatory effects. PURPOSE: This study assessed the in vitro effect of SOL on promastigotes and Leishmania amazonensis-infected macrophages, as well its microbicide and immunomodulatory mechanisms. METHODS: SOL was isolated from the roots of S. chilensis, 98% purity, and identified by chromatographic methods, and the effect of SOL on leishmanicidal activity against promastigotes in vitro, SOL-induced cytotoxicity in THP-1, J774 cells, sheep erythrocytes, and L. amazonensis-infected J774 macrophages, and the mechanisms of death involved in this action were evaluated. RESULTS: In silico predictions showed good drug-likeness potential for SOL with high oral bioavailability and intestinal absorption. SOL treatment (10-160 µM) inhibited promastigote proliferation 24, 48, and 72 h after treatment. After 24 h of treatment, SOL at the IC50 (34.5 µM) and 2 × the IC50 (69 µM) induced several morphological and ultrastructural changes in promastigotes, altered the cell cycle and cellular volume, increased phosphatidylserine exposure on the cell surface, induced the loss of plasma membrane integrity, increased the reactive oxygen species (ROS) level, induced loss of mitochondrial integrity (characterized by an apoptosis-like process), and increased the number of lipid droplets and autophagic vacuoles. Additionally, SOL induced low cytotoxicity in J774 murine macrophages (CC50 of 1587 µM), THP-1 human monocytes (CC50 of 1321 µM), and sheep erythrocytes. SOL treatment reduced the percentage of L. amazonensis-infected macrophages and the number of amastigotes per macrophage (IC50 9.5 µM), reduced TNF-α production and increased IL-12p70, ROS and nitric oxide (NO) levels. CONCLUSION: SOL showed in vitro leishmanicidal effects against the promastigotes by apoptosis-like mechanism and amastigotes by reducing TNF-α and increasing IL-12p70, ROS, and NO levels, suggesting their potential as a candidate for use in further studies on the design of antileishmanial drugs.

Solidagenone from Solidago chilensis Meyen inhibits skin inflammation in experimental models.

Solidagenone (SOL) is a labdane-type diterpenoid found in Solidago chilensis, a plant traditionally used to treat skin diseases, kidney pain and ovarian inflammation. In this study, the topical anti-inflammatory activity of SOL was evaluated using in vivo and in silico assays. Croton oil-, arachidonic acid (AA)- and phenol-induced ear oedema mouse models were applied in the in vivo studies. Myeloperoxidase (MPO) and N-acetyl-ß-D-glucosaminidase (NAG) activities and tumour necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and nitric oxide (NO) levels were determined, as well as histopathological analyses were conducted. Interaction profiles between SOL and cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), glucocorticoid receptor, estradiol-17-ß-dehydrogenase and prostaglandin-E(2)-9-reductase were established using molecular docking. SOL significantly inhibited croton oil-, AA- and phenol-induced ear oedema (P < .001) at doses of 0.1, 0.5 and 1.0 mg/ear. The MPO and NAG activities and TNF-α, IL-6 and NO levels were decreased (P < .001). The histopathological data revealed that inflammatory parameters (oedema thickness, leucocyte infiltration and vasodilatation) were reduced by treatment with SOL at doses of 0.1, 0.5 and 1.0 mg/ear. The docking study showed that SOL interacts with COX-1 and prostaglandin-E(2)-9-reductase through hydrogen bonding, inhibiting these enzymes. These results indicate that SOL may be a promising compound for the treatment of cutaneous inflammatory disorders and has potential as a topical anti-inflammatory agent.

Solidago chilensis Meyen (Asteraceae), a medicinal plant from South America: a comprehensive review: ethnomedicinal uses, phytochemistry and bioactivity / Solidago chilensis Meyen (Asteraceae), una planta medicinal de América del Sur: una revisión integral: usos etnomedicinales, fitoquímica y bioactividad

Solidago chilensis Meyen (Asteraceae) is a medicinal and aromatic herb widely distributed in South America. From 2000 to the present numerous articles on this species have been published, mainly in the last decade where the pharmacological studies and articles on its secondary metabolites have risen sharply. S. chilensis has potential beneficial effects on human health, particularly as an anti- inflammatory because of its high flavonoid content. This work describes the research carried out on this species with emphasis on biological and phytochemical studies.

Solidago chilensis Meyen (Asteraceae) es una hierba aromática y medicinal, ampliamente difundida en Sudamérica. A partir del año 2000 se publicaron numerosos estudios sobre esta planta, particularmente en la última década donde se incrementó sensiblemente el estudio de sus propiedades farmacológicas y de la química de sus metabolitos secundarios. Es una planta con propiedades potencialmente beneficiosas para la salud humana, destacándose particularmente por su actividad antiinflamatoria que puede ser atribuida al elevado contenido en flavonoides. En este trabajo revisamos exhaustivamente los antecedentes de esta planta desde un enfoque cronológico, con énfasis en los estudios biológicos y fitoquímicos.