Escin attenuates acute lung injury induced by endotoxin in mice

Biomaterial-based combinatorial approach of aescin-comprised zein-coated gelatin nanoparticles alleviates synovial inflammation in experimental inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that mostly affects joints. Although RA therapy has made significant progress, difficulties including extensive medication metabolism and its quick clearance result in its inadequate bioavailability. The anti-inflammatory effect of zein was reported with other medications, but it has certain limitations. There are reports on the anti-oxidant and anti-inflammatory effect of aescin, which exhibits low bioavailability for the treatment of rheumatoid arthritis. Also, the combinatorial effect of zein with other effective drug delivery systems is still under investigation for the treatment of experimental collagen-induced rheumatoid arthritis. The focus of this study was to formulate and define the characteristics of zein-coated gelatin nanoparticles encapsulated with aescin (Ze@Aes-GNPs) and to assess and contrast the therapeutic effectiveness of Ze@Aes-GNPs towards collagen-induced RA in Wistar rats. Nanoprecipitation and the layer-by-layer coating process were used to fabricate Ze@Aes-GNPs and their hydrodynamic diameter was determined to be 182 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to further validate the size, shape, and surface morphology of Ze@Aes-GNPs. When tested against foreskin fibroblasts (BJ), these nanoparticles demonstrated significantly high cytocompatibility. Both Aes and Ze@Aes-GNPs were effective in treating arthritis, as shown by the decreased edoema, erythema, and swelling of the joints, between which Ze@Aes-GNPs were more effective. Further, it was demonstrated that Aes and Ze@Aes-GNPs reduced the levels of oxidative stress (articular elastase, lipid peroxidation, catalase, superoxide dismutase and nitric oxide) and inflammatory indicators (TNF-α, IL-1β and myeloperoxidase). The histopathology findings further demonstrated that Ze@Aes-GNPs considerably reduced the infiltration of inflammatory cells at the ankle joint cartilage compared to Aes. Additionally, immunohistochemistry examination showed that treatment with Ze@Aes-GNPs suppressed the expression of pro-inflammatory markers (COX-2 and IL-6) while increasing the expression of SOD1. In summary, the experiments indicated that Aes and Ze@Aes-GNPs lowered the severity of arthritis, and critically, Ze@Aes-GNPs showed better effectiveness in comparison to Aes. This suppression of oxidative stress and inflammation was likely driven by Aes and Ze@Aes-GNPs.

Oral delivery of aescin-loaded gelatin nanoparticles ameliorates carbon tetrachloride-induced hepatotoxicity in Wistar rats

AIM

The liver plays a crucial role in biotransformation but it is susceptible to chemical-induced damage, known as hepatotoxicity. Traditional therapies for protecting the liver face significant challenges, including poor bioavailability, off-target effects, adverse reactions, drug breakdown, and inadequate uptake. These issues emphasize the need for precise, targeted therapeutic approaches against hepatotoxicity.

MATERIALS AND METHODS

The objective of our research was to develop a customized, biocompatible, and biodegradable nanodrug delivery system for hepatoprotection. We chose collagen hydrolyzed protein, or gelatin, as the base material and utilized solvent evaporation and nanoprecipitation methods to create nanoparticles with size ranging from 130 to 155 nm. The resulting nanoparticles exhibited a spherical and smooth surface, as confirmed by scanning and transmission electron microscopy.

KEY FINDINGS

Bioactive aescin (AES), into these gelatin nanoparticles (AES-loaded gel NPs), we tested these nanoparticles using a hepatotoxicity model. The results were indicating a significant reduction in the levels of key biomolecules, including NF-κB, iNOS, BAX, and COX-2 and decreased serum levels of enzymes ALT and AST. This reduction correlated with a notable alleviation in the severity of hepatotoxicity. Furthermore, the treatment with AES-loaded gel NPs resulted in the downregulation of several inflammatory and liver-specific biomarkers, including nitrite, MPO, TNF-α, and IL-6.

SIGNIFICANCE

In summary, our study demonstrates that the AES-loaded gel NPs were markedly more effective in mitigating experimental hepatotoxicity when compared to the free aescin. The nanoparticles exhibited a propensity for suppressing liver damage, showcasing the potential of this targeted therapeutic approach for safeguarding the liver from harmful chemical insults.

Escin's Multifaceted Therapeutic Profile in Treatment and Post-Treatment of Various Cancers: A Comprehensive Review

Although modern medicine is advancing at an unprecedented rate, basic challenges in cancer treatment and drug resistance remain. Exploiting natural-product-based drugs is a strategy that has been proven over time to provide diverse and efficient approaches in patient care during treatment and post-treatment periods of various diseases, including cancer. Escin-a plant-derived triterpenoid saponin-is one example of natural products with a broad therapeutic scope. Initially, escin was proven to manifest potent anti-inflammatory and anti-oedematous effects. However, in the last two decades, other novel activities of escin relevant to cancer treatment have been reported. Recent studies demonstrated escin's efficacy in compositions with other approved drugs to accomplish synergy and increased bioavailability to broaden their apoptotic, anti-metastasis, and anti-angiogenetic effects. Here, we comprehensively discuss and present an overview of escin's chemistry and bioavailability, and highlight its biological activities against various cancer types. We conclude the review by presenting possible future directions of research involving escin for medical and pharmaceutical applications as well as for basic research.

Saponins: Research Progress and Their Potential Role in the Post-COVID-19 Pandemic Era

In the post-COVID-19 pandemic era, the new global situation and the limited therapeutic management of the disease make it necessary to take urgent measures in more effective therapies and drug development in order to counteract the negative global impacts caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new infectious variants. In this context, plant-derived saponins-glycoside-type compounds constituted from a triterpene or steroidal aglycone and one or more sugar residues-may offer fewer side effects and promising beneficial pharmacological activities. This can then be used for the development of potential therapeutic agents against COVID-19, either as a therapy or as a complement to conventional pharmacological strategies for the treatment of the disease and its prevention. The main objective of this review was to examine the primary and current evidence in regard to the therapeutic potential of plant-derived saponins against the COVID-19 disease. Further, the aim was to also focus on those studies that highlight the potential use of saponins as a treatment against SARS-CoV-2. Saponins are antiviral agents that inhibit different pharmacological targets of the virus, as well as exhibit anti-inflammatory and antithrombotic activity in relieving symptoms and clinical complications related to the disease. In addition, saponins also possess immunostimulatory effects, which improve the efficacy and safety of vaccines for prolonging immunogenicity against SARS-CoV-2 and its infectious variants.

Hepatoprotective functions of jujuboside B

Jujuboside B (JB) found in the seeds of Zizyphi Spinosi Semen possesses pharmacological functions, such as anti-inflammatory, antiplatelet aggregation, and antianxiety potentials. This study evaluated the effect of JB on liver failure in cecal ligation and puncture (CLP)-induced sepsis. First, we observed histopathological changes in the liver by optical microscopy and the activity of enzymes in serum such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). We further measured the levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, nitric oxide (NO), and antioxidative parameters in liver homogenate. The expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), and glucocorticoid receptor (GR) in the liver was observed by Western blotting. CLP enhanced the migration of inflammatory cells, ALT and AST concentrations, and necrosis, which were reduced by JB. In addition, JB reduced 11β-HSD2 expression and levels of inflammatory mediators (TNF-α, IL-1β, and NO) in the liver, increased GR expression, enhanced endogenous antioxidative capacity. These results further suggest that JB may protect the liver against CLP-induced damage by regulating anti-inflammatory responses, downregulating 11β-HSD2 expression and antioxidation, and up-regulating GR expression.

Integrated systematic pharmacology analysis and experimental validation to reveal the mechanism of action of Semen aesculi on inflammatory bowel diseases

BACKGROUND AND ETHNOPHARMACOLOGICAL RELEVANCE

Semen aesculi (SA), a traditional Chinese herb, has been used in the treatment of gastrointestinal disease for thousands of years. The escin was the main components of SA. A growing number of research showed that escin has a wide range of pharmacological activities in intestinal barrier dysfunction.

AIM OF THE STUDY

Inflammatory bowel diseases (IBD) are an idiopathic disease of the intestinal tract with the hallmark features of mucosal inflammation and loss of barrier function. The theory of traditional Chinese medicine (TCM) suggests that SA plays a potential role in protecting the gastrointestinal diseases. The present study aimed to explore the effects of SA on the intestinal barrier under existing inflammatory conditions and elucidate underlying mechanisms.

MATERIALS AND METHODS

The bioactive components of SA and their predicted biological targets were combined to develop a compound target pathway network. It is used to predict the bioactive components, molecular targets, and molecular pathways of SA in improving IBD. The ingredients of SA were extracted by decoction either in water and ethanol and separated into four fractions (AE, EE, PEE and PCE). The effects of extractions were evaluated in the lipopolysaccharide (LPS)-induced RAW264.7 macrophages cell model, LPS-induced intestinal barrier injury model and imodium-induced constipation model. The high-performance liquid chromatography (HPLC) analysis was performed to identify the bioactive components.

RESULTS

The compound-target pathway network was identified with 10 bioactive compounds, 166 IBD-related targets, and 52 IBD-related pathways. In LPS-induced RAW264.7 cells, PEE and PCE significantly decreased nitric oxide (NO) production and TNF-α level. In mice, PEE and PCE administration improved intestinal barrier damage, increased intestinal motility, reduced levels of TNF-α and diamine oxidase (DAO). Furthermore, PEE and PCE administration not only decreased expression of p-Akt, p-IκBα, nuclear p-p65, and TNF-α level, but also increased expression of the zonula occludin-1 (ZO-1) in LPS-induced intestinal barrier injury model. The escin content of AE, EE, PEE and PCE gradually increased with an increase of the bioactivity.

CONCLUSIONS

Escin was the main bioactive components of SA. The effects of SA on IBD were mediated by repairing the intestinal barrier and promoting intestinal motility. The mechanism of action of SA is related to inhibiting the Akt/NF-κB signaling pathway in intestinal tissue, at least, in part. Our results provide a scientific basis for further exploring the mechanisms involved in the beneficial effects of SA in IBD.

The long winding road to the safer glucocorticoid receptor (GR) targeting therapies

Glucocorticoids (Gcs) are widely used to treat inflammatory diseases and hematological malignancies, and despite the introduction of novel anti-inflammatory and anti-cancer biologics, the use of inexpensive and effective Gcs is expected to grow. Unfortunately, chronic treatment with Gcs results in multiple atrophic and metabolic side effects. Thus, the search for safer glucocorticoid receptor (GR)-targeted therapies that preserve therapeutic potential of Gcs but result in fewer adverse effects remains highly relevant. Development of selective GR agonists/modulators (SEGRAM) with reduced side effects, based on the concept of dissociation of GR transactivation and transrepression functions, resulted in limited success, and currently focus has shifted towards partial GR agonists. Additional approach is the identification and inhibition of genes associated with Gcs specific side effects. Others and we recently identified GR target genes REDD1 and FKBP51 as key mediators of Gcs-induced atrophy, and selected and validated candidate molecules for REDD1 blockage including PI3K/Akt/mTOR inhibitors. In this review, we summarized classic and contemporary approaches to safer GR-mediated therapies including unique concept of Gcs combination with REDD1 inhibitors. We discussed protective effects of REDD1 inhibitors against Gcs–induced atrophy in skin and bone and underlined the translational potential of this combination for further development of safer and effective Gcs-based therapies.

Aescin Protects against Experimental Benign Prostatic Hyperplasia and Preserves Prostate Histomorphology in Rats via Suppression of Inflammatory Cytokines and COX-2

Background: Benign prostatic hyperplasia (BPH) is the most common urogenital condition in aging males, while inflammation and tissue proliferation constitute the main pathophysiological factors. The adverse effects of currently available BPH medications limit patient compliance. We tested the protective effect of aescin against the development of BPH in rats. Methods: A total of 18 male Wistar rats were divided into 3 groups: control (sesame oil 1 mL/kg, s.c.); BPH (testosterone oenanthate 3 mg/kg, s.c., in sesame oil), and BPH-aescin rats (testosterone oenanthate 3 mg/kg, s.c. + aescin 10 mg/kg/day, p.o.). All treatments continued for 4 weeks. Serum and prostatic samples were harvested for biochemical and histopathological examination. Results: Induction of BPH by testosterone increased the prostate weight and prostate weight index, serum testosterone, prostate expression of inflammatory (IL-1β, TNF-α, and COX-2), and proliferative markers (PCNA and TGF-β1). Concurrent treatment with aescin decreased the testosterone-induced increase in prostatic IL-1β, TNF-α, and COX-2 expression by 47.9%, 71.2%, and 64.4%, respectively. Moreover, aescin reduced the prostatic proliferation markers TGF-β1 and PCNA by 58.3% and 71.9%, respectively, and normalized the prostate weight. Conclusion: The results of this study showed, for the first time, that aescin protected against the development of experimental BPH in rats via its anti-inflammatory and antiproliferative effects. These findings warrant further studies to clinically repurpose aescin in the management of BPH.

Optimization of ultrasound extraction of Tribulus terrestris L. leaves saponins and their HPLC-DAD-ESI-MSn profiling, anti-inflammatory activity and mechanism in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tribulus terrestris L., as an annual herb plant from Zygophyllaceae, exhibits many biological activities, and its main chemical constituents are saponins. However, the extraction process, chemical compositions, anti-inflammatory effect and mechanism of total saponins from Tribulus terrestris L. leaves are still unclear.

AIM OF THE STUDY

The present study extensively evaluated the extraction process, major components, anti-inflammatory action and mechanism of Tribulus terrestris L. leaves saponins.

MATERIALS AND METHODS

The ultrasonic extraction and response surface methods were adopted for optimization of extraction technology of total saponins from Tribulus terrestris L. leaves, and its compositions were detected with LC-MSⁿ method. The anti-inflammatory activity of total saponins was studied by lipopolysaccharide induced RAW 264.7 cells and acute lung injury mice models.

RESULTS

The ultrasonic extraction parameters of saponins fraction, including ethanol concentration 30%, extraction time 55 min, ratio of solvent to material 35:1 ml/g and extraction temperature 46 °C, were screened by response surface method with the extracting rate 5.49%, and thirty compositions were detected with LC-MSⁿ method. Moreover, saponins fraction can play a stronger anti-inflammatory effect by reducing the phagocytic activity and pulmonary edema, and protection of morphology of RAW 264.7 cells and lung tissues, and decreasing the content of NO and TNF-α. Moreover, it was revealed that total saponins extract can exert the anti-inflammatory action by the inhibition of the activation of the TLR4-TRAF6-NF-κB signalling pathway.

CONCLUSION

These studies imply that Tribulus terrestris L. leaves saponins may be an important anti-inflammatory drug in clinic.

Glucocorticoid-Like Activity of Escin: A New Mechanism for an Old Drug

Saponins are a group of compounds used in clinical practice in the management of several diseases. Escin is a natural mixture of triterpene saponins which mainly consist of several isoforms, in which the α- and β-escin are predominant. β-escin is the major active compound that exerts a therapeutic effect by relieving tissue edema, promoting venous drainage, and reducing inflammation. In this review, we describe the features of its glucocorticoid-like activity that could explain its clinical effects. Using PubMed, Embase Cochrane library and reference lists for articles published until October 01, 2020, we documented that escin is likely able to exert its anti-inflammatory and anti-edematous effects through a glucocorticoid-like activity, but without the development of glucocorticoid-like adverse drug reactions.

Molecular docking analyses of Escin as regards cyclophosphamide-induced cardiotoxicity: In vivo and in Silico studies

This study aims to investigate whether Escin (ES) can protect against Cyclophosphamide (CPM)-induced cardiac damage. The experimental rats were categorized as Control, CPM (200 mg/kg), ES (10 mg/kg), and CPM + ES Groups, each having 6 members. Their heart tissues were stained with Hematoxylin and Eosin and the structural changes were investigated under the light microscope. The biochemical markers of ischemia modified albumin (IMA), creatine kinase (CK-MB), antioxidant activity indicators Catalase (CAT), and superoxide dismutase (SOD) activities were measured using blood samples. Besides, the effects of CPM, ES, and CPM + ES upon CAT and SOD activities were shown via molecular docking studies. In the Single-Dose CPM group, CK-MB and IMA levels significantly increased while SOD and CAT levels significantly decreased. However, the heart tissues were damaged. CK-MB and IMA levels significantly decreased in CP+ ES Group. On the other hand, SOD, and CAT levels significantly increased and reduced the damage remarkably. Our findings showed that ES treatment successfully reduced the toxic effects upon the rats. The conclusion is that ES treatment can help protect the heart tissue against CPM-induced toxicity. Both in-vivo results and molecular modeling studies showed that the negative effects of CPM upon SOD activity were bigger than that of CAT.

The Use of Herbal Medicines for the Prevention of Glucocorticoid-Induced Osteoporosis

Glucocorticoids are drugs that are widely used to suppress inflammation and the activation of the immune system. However, the prolonged use or at high doses of glucocorticoid can result in adverse side effects including osteoporosis, bone loss, and an increased risk of fracture. A number of compounds derived from natural plant sources have been reported to exert anti-inflammatory activity by interacting with the glucocorticoid receptor (GR), likely owing to their chemical similarity to glucocorticoids, or by regulating GR, without a concomitant risk of treatment-related side effects such as osteoporosis. Other herbal compounds can counteract the pathogenic processes underlying glucocorticoid-induced osteoporosis (GIOP) by regulating homeostatic bone metabolic processes. Herein, we systematically searched the PubMed, Embase, and Cochrane library databases to identify articles discussing such compounds published as of May 01, 2021. Compounds reported to exert anti-inflammatory glucocorticoid-like activity without inducing GIOP include escin, ginsenosides, and glycyrrhizic acid, while compounds reported to alleviate GIOP by improving osteoblast function or modulating steroid hormone synthesis include tanshinol and icariin.

Anti-Inflammatory and Gastroprotective Effects of Escin

Escin is a triterpenoid saponin extracted from the fruit of Aesculus wilsonii Rehd. and Aesculus hippocastanum (Hippocastanaceae). Clinically, it is widely used in the treatment of edema induced by either trauma or surgery, as well as treating chronic venous insufficiency. The anti-inflammatory and antiedema effects of escin have been extensively investigated. This article systematically reviews the effects of escin on inflammation and gastrointestinal diseases, including its role in inflammation, as an antioxidant, and in inhibiting gastric acid secretion and promoting gastrointestinal movement, especially, the molecular mechanism. The advantages and potential uses of escin have also been discussed.

Escin ameliorates the impairments of neurological function and blood brain barrier by inhibiting systemic inflammation in intracerebral hemorrhagic mice

This study aims to investigate whether escin ameliorates the impairments of neurological function by ameliorating systemic inflammation instead of targeting the brain directly in intracerebral hemorrhage (ICH) mice. It showed that escin did not cross the blood brain barrier (BBB). Compared with the ICH group, the Garcia test scores in the escin groups were significantly increased. Brain water contents and Evans blue extravasation of the right basal ganglia in the ICH group were augmented, and significantly reduced by escin. Escin abated the increases of monocyte counts and serum IL-1β levels induced by ICH. IL-1β administration reversed the effect of escin on Garcia test scores, the brain water contents, and the Evans blue extravasation. Escin ameliorated the increasing levels of RhoA, ROCK1, nuclear NF-κB and the decreasing expression of IκBα, cytosolic NF-κB, occludin, claudin-5 in the ICH group. IL-1β administration blocked not only escin-mediated increases of IκBα, cytosolic NF-κB, occludin, and claudin-5, but also escin-caused decreases of RhoA, ROCK1, and nuclear NF-κB. The results indicate that escin improves neurological outcomes and the BBB function in ICH mice, which is associated with attenuating ICH-induced peripheral system inflammation, and therefore, inhibiting IL-1β/RhoA/NF-κB signaling pathway in BBB, at least in part. These findings suggest that it may be useful to ameliorate brain injury by inhibiting systemic inflammation instead of aiming to target the brain directly after ICH.

Escin attenuates oxidative damage, apoptosis and lipid peroxidation in a model of cyclophosphamide-induced liver damage

To investigate the effects of escin (ES) on acute damage induced by alkylating agent, experimental rats were injected with cyclophosphamide (CPM) to cause liver damage. The animals were divided into four groups: Control Group, CPM (200 mg/kg), ES (10 mg/kg), CPM, and ES Groups. Immunohistopathological, hepatic histopathological, and biochemical changes were analyzed. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), malondyaldehyde (MDA), glutathion (GSH), total oxidant status (TOS) and total antioxidant status (TAS) in serum were all determined. Serum and immunohistopathology analysis revealed that MDA, ALT, AST, LDH, TOC and OSI, caspase-3 and Bax levels had increased while GSH, TAC, Bcl- 2 and OSI levels decreased in CPM Group when compared to Control Group. These findings appear to account for the severe damage detected. In the CPM + ES treated group, positive improvements were found in biochemical parameters as well as in cell-death and tissue-related damage parameters.The results show that ES considerably protects the rat liver against CPM-induced hepatotoxicity thanks to because of its anti-oxidant and anti-apoptotic properties.

Severe Acute Lung Injury Related to COVID-19 Infection: A Review and the Possible Role for Escin

Acute lung injury (ALI) represents the most severe form of the viral infection sustained by coronavirus disease 2019 (COVID-19). Today, it is a pandemic infection, and even if several compounds are used as curative or supportive treatment, there is not a definitive treatment. In particular, antiviral treatment used for the treatment of several viral infections (eg, hepatitis C, HIV, Ebola, severe acute respiratory syndrome-coronavirus) are today used with a mild or moderate effect on the lung injury. In fact, ALI seems to be related to the inflammatory burst and release of proinflammatory mediators that induce intra-alveolar fibrin accumulation that reduces the gas exchange. Therefore, an add-on therapy with drugs able to reduce inflammation, edema, and cell activation has been proposed as well as a treatment with interferon, corticosteroids or monoclonal antibodies (eg, tocilizumab). In this article reviewing literature data related to the use of escin, an agent having potent anti-inflammatory and anti-viral effects in lung injury, we suggest that it could represent a therapeutic opportunity as add-on therapy in ALI related to COVID-19 infection.

Natural barrigenol-like triterpenoids: A comprehensive review of their contributions to medicinal chemistry

Barrigenol-like triterpenoids (BATs), which contain an unusual oleanane substituted by many hydroxyl groups as the skeleton, are subdivided into five subtypes: barrigenol A₁, barrigenol A₂, barrigenol R₁, barringtogenol C, and 16-deoxybarringtogenol C. The variations in acyl derivatives, hydroxyl groups, and carbohydrate chains in their structures have enhanced the diversity of BATs. Moreover, the stable polyhydroxy-replaced pentacyclic skeleton provides an ideal platform for structural modifications. To date, more than 500 BAT derivatives have been isolated from plants. Synchronously, BATs possess anti-tumour, anti-Alzheimer's disease, anti-inflammatory, anti-microbial, anti-obesity and anti-allergic activities by regulating numerous cellular molecules. Some BAT derivatives, such as escin obtained from Aesculus hippocastanum L. and xanthoceraside isolated from Xanthoceras sorbifolia Bunge, have been used to treat encephaloedema or inflammatory diseases. This review aims to provide comprehensive information about the chemistry, sources, bioavailability, and anti-tumour effects of BATs, with a particular emphasis on the molecular mechanisms of action. The pharmacokinetics and clinical progress are also concerned. More than 300 structures identified over past 25 years are summarized here (249 compounds) and in the supplementary information (114 compounds). Accordingly, the pharmaceutical activity of barrigenol triterpenoids suggests that some compounds should be developed as promising anti-tumour or anti- Alzheimer's disease agents in future.

Network Pharmacology Based Research on the Combination Mechanism Between Escin and Low Dose Glucocorticoids in Anti-rheumatoid Arthritis

Rheumatoid arthritis (RA) is characterized by chronic progressive symmetrical synovitis and destruction of multiple joints. Glucocorticoids (GCs) are widely used in the treatment of RA. However, their adverse effects can be serious. Escin, which is isolated from Aesculus hippocastanum L., has been reported to have anti-inflammatory effects. We investigated the anti-RA effect of Escin combined with low dose GCs (dexamethasone, Dex) and the underlying mechanism. Adjuvant-induced RA rats and lipopolysaccharides (LPS)-injured RAW264.7 cells were used to investigate the anti-RA effects of Escin combined with low dose Dex in vivo and in vitro. The results showed that Escin combined with low-dose Dex significantly decreased arthritic index, serum IL-6 and TNF-α levels, reduced paw swelling, and ameliorated the joint pathology and immune organ pathology. Gene chip results revealed that Nr3c1 (GR) expression was significantly altered, and that GR was activated by Escin and low dose Dex in vivo and in vitro. Additionally, Escin combined with low dose Dex also significantly increased GR mRNA expression. However, when GR expression was suppressed by its specific inhibitor, the anti-RA effect of Escin combined with low-dose Dex was abolished. The data in this study demonstrated that Escin combined with Dex reduced the dose of Dex, and exerted significant anti-RA effects, which could also reduce the adverse effects of Dex. This combination might result from GR activation. This study might provide a new combination of drugs for the treatment of RA.

Inhibition of Migration and Invasion in Melanoma Cells by β-Escin via the ERK/NF-κB Signaling Pathway

β-Escin, a natural triterpene saponin was extracted from Aesculus hippocastanum seeds, which have been widely used to treat inflammation in traditional medicine. In an effort to study the possible anti-tumor effects of β-escin, we performed wound healing, invasion, and adhesion assays to examine the effects of β-escin on cell migration, invasion, and angiogenesis. Our results revealed that β-escin inhibits cell migration as well as motility in B16F10 and SK-MEL5 cells in a dose-dependent manner. RT-PCR and Western blot analysis showed that β-escin increased TIMP-1, -2 while significantly downregulated phosphorylated extracellular signal-regulated kinase (p-ERK) expression, and suppressing nuclear factor-kappa B (NF-κB) and inhibitor of nuclear factor-kappa B (IκB) expression. Overall, the data from the current study suggest that β-escin has the potential for inhibiting both metastatic and angiogenic activities, and are the earliest evidence for the involvement of the NF-κB/IκB signaling in β-escin-induced anti-tumor effects.

Anti-inflammatory effect of external use of escin on cutaneous inflammation: possible involvement of glucocorticoids receptor

Escin, as an internally applied anti-inflammatory agent, has been widely used in the treatment of inflammation and edema resulting from trauma or operation in the clinic. However, the effect of its external use on cutaneous inflammation and edema remains unexplored. In the present study, the anti-inflammatory and anti-edematous effects of external use of escin were studied in carrageenan-induced paw edema and histamine-induced capillary permeability in rats, paraxylene-induced ear swelling in mice, and cotton pellet-induced granuloma in rats. Effects of external use of escin gel on prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were determined by ELISA. The anti-inflammatory mechanism was explored by detecting the expression of glucocorticoid receptor (GR) with Western blotting and Real-time PCR analyses, with further exploration of nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (P38MAPK) and activator protein-1 (AP-1) expressions. We demonstrated that external use of escin showed significant anti-inflammatory effects on acute and chronic inflammation in different animal models and its anti-inflammatory effects might be related to down-regulation of PGE2, TNF-α, and IL-1β. The results also showed that escin exerted its anti-inflammatory effects by promoting the expression of GR, with the possible mechanism being inhibition of the expressions of GR-related signaling molecules such as NF-κB and AP-1.

Endothelia-Targeting Protection by Escin in Decompression Sickness Rats

Endothelial dysfunction is involved in the pathogenesis of decompression sickness (DCS) and contributes substantively to subsequent inflammatory responses. Escin, the main active compound in horse chestnut seed extract, is well known for its endothelial protection and anti-inflammatory properties. This study aimed to investigate the potential protection of escin against DCS in rats. Escin was administered orally to adult male rats for 7 d (1.8 mg/kg/day) before a simulated air dive. After decompression, signs of DCS were monitored, and blood and pulmonary tissue were sampled for the detection of endothelia related indices. The incidence and mortality of DCS were postponed and decreased significantly in rats treated with escin compared with those treated with saline (P < 0.05). Escin significantly ameliorated endothelial dysfunction (increased serum E-selectin and ICAM-1 and lung Wet/Dry ratio, decreased serum NO), and oxidative and inflammatory responses (increased serum MDA, MPO, IL-6 and TNF-α) (P < 0.05 or P < 0.01). The results suggest escin has beneficial effects on DCS related to its endothelia-protective properties and might be a drug candidate for DCS prevention and treatment.

Otitis media induced by peptidoglycan-polysaccharide (PGPS) in TLR2-deficient (Tlr2(-/-)) mice for developing drug therapy

BACKGROUND

Toll like receptor 2 (TLR2) signaling can regulate the pathogenesis of otitis media (OM). However, the precise role of TLR2 signaling in OM has not been clarified due to the lack of an optimal animal model. Peptidoglycan-polysaccharide (PGPS) of the bacterial cell wall can induce inflammation by activating the TLR2 signaling. This study aimed at examining the pathogenic characteristics of OM induced by PGPS in Tlr2(-/-) mice, and the potential therapeutic effect of sodium aescinate (SA) in this model.

METHODS

Wild-type (WT) and Tlr2(-/-) mice were inoculated with streptococcal PGPS into their middle ears (MEs) and treated intravenously with vehicle or SA daily beginning at 3days prior to PGPS for 6 consecutive days. The pathologic changes of individual mice were evaluated longitudinally.

RESULTS

In comparison with WT mice, Tlr2(-/-) mice were susceptible to PGPS-induced OM. Tlr2(-/-) mice displayed greater hearing loss, tympanic membrane damage, ME mucosal thickening, longer inflammation state, cilia and goblet cell loss. SA-treatment decreased neutrophil infiltration, modulated TLR2-related gene expression and improved ciliary organization.

CONCLUSIONS

PGPS induced a relatively stable OM in Tlr2(-/-) mice, providing a new model for OM research. Treatment with SA mitigated the pathogenic damage in the ME and may be valuable for intervention of OM.

Oral Administration of Escin Inhibits Acute Inflammation and Reduces Intestinal Mucosal Injury in Animal Models

The present study aimed to investigate the effects of oral administration of escin on acute inflammation and intestinal mucosal injury in animal models. The effects of escin on carrageenan-induced paw edema in a rat model of acute inflammation, cecal ligation and puncture (CLP) induced intestinal mucosal injury in a mouse model, were observed. It was shown that oral administration of escin inhibits carrageenan-induced paw edema and decreases the production of prostaglandin E2 (PGE2) and cyclooxygenase- (COX-) 2. In CLP model, low dose of escin ameliorates endotoxin induced liver injury and intestinal mucosal injury and increases the expression of tight junction protein claudin-5 in mice. These findings suggest that escin effectively inhibits acute inflammation and reduces intestinal mucosal injury in animal models.

The total alkaloids of Aconitum tanguticum protect against lipopolysaccharide-induced acute lung injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum tanguticum has been widely used as a remedy for infectious diseases in traditional Tibetan medicine in China. The total alkaloids of Aconitum tanguticum (TAA) are the main active components of Aconitum tanguticum and have been demonstrated to be effective in suppressing inflammation. Our aim was to investigate the protective effects of TAA on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in rats.

MATERIALS AND METHODS

TAA was extracted in 95% ethanol and purified in chloroform. After vacuum drying, the TAA powder was dissolved in dimethyl sulfoxide. Adult male Sprague-Dawley rats were randomly divided into six groups. Rats were given dexamethasone (DXM, 4 mg/kg) or TAA (60 mg/kg, 30 mg/kg) before LPS injection. The PaO2and PaO2/FiO2 values, lung wet/dry (W/D) weight ratio and histological changes in lung tissue were measured. The cell counts, protein concentration, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in bronchoalveolar lavage fluid (BALF), and myeloperoxidase (MPO) activity in lung tissue were determined at 6, 12 or 24 h after LPS treatment. In addition, the NF-κ B activation in lung tissue was analyzed by western blot.

RESULTS

In ALI rats, TAA significantly reduced the lung W/D ratio and increased the value of PaO2 or PaO2/FiO2 at 6, 12 or 24 h after LPS challenge. TAA also reduced the total protein concentration and the number of total cells, neutrophils or lymphocytes in BALF. In addition, TAA decreased MPO activity in the lung and attenuated histological changes in the lung. Furthermore, TAA inhibited the concentration of TNF-α, IL-6 and IL-1β in BALF at 6, 12 or 24 h after LPS treatment. Further study demonstrated that TAA significantly inhibited NF-κ B activation in lung tissue.

CONCLUSIONS

The current study proved that TAA exhibited a potent protective effect on LPS-induced ALI in rats through its anti-inflammatory activity.

Escin attenuates behavioral impairments, oxidative stress and inflammation in a chronic MPTP/probenecid mouse model of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder that results mainly due to the death of dopaminergic neurons in the substantia nigra (SN), and subsequently has an effect on one's motor function and coordination. The current investigation explored the neuroprotective potential of escin, a natural triterpene-saponin on chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid (MPTP/p) induced mouse model of PD. Administration of MPTP led to the depleted striatal dopamine content, impaired patterns of behavior, enhanced oxidative stress and diminished expression of tyrosine hydroxylase (TH), dopamine transporter (DAT) and vesicular monoamine transporter-2 (VMAT-2). The expressions of interleukin-6 and -10, glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1 (IBA-1), tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) in SN were also enhanced. Oral treatment of escin significantly attenuated MPTP/p induced dopaminergic markers depletion, physiological abnormalities, oxidative stress and inhibit neuroinflammatory cytokine expressions in SN. The result of our study confirmed that escin mediated its protection against experimental PD through its antioxidant and anti-inflammatory properties.

Cytotoxic Effects of Four Aescin Types on Human Colon Adenocarcinoma Cell Lines

Four types of aescin that are available on the pharmaceutical market, β-aescin crystalline, β-aescin amorphous, β-aescin sodium and aescin polysulfate, have been analyzed for their cytotoxic effects on human colon adenocarcinoma (LoVo) and doxorubicin-resistant human colon adenocarcinoma cell lines (LoVo/Dx). Their cytotoxic activities were evaluated by sulforhodamine B (SRB) and methyl tetrazolium (MTT) assays. All four types of aescin exerted strong dose-dependent cytotoxicity to LoVo and, to a lesser degree, LoVo/Dx cell lines. The IC50 value for the LoVo/Dx cell line was higher, but still dose-dependent. Results from both assays demonstrated that β-aescin crystalline has the most cytotoxic activity toward human colon adenocarcinoma cell lines.

Potential effects of medicinal plants and secondary metabolites on acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. ALI is characterized by increased permeability of the alveolar-capillary membrane, edema, uncontrolled neutrophils migration to the lung, and diffuse alveolar damage, leading to acute hypoxemic respiratory failure. Although corticosteroids remain the mainstay of ALI treatment, they cause significant side effects. Agents of natural origin, such as medicinal plants and their secondary metabolites, mainly those with very few side effects, could be excellent alternatives for ALI treatment. Several studies, including our own, have demonstrated that plant extracts and/or secondary metabolites isolated from them reduce most ALI phenotypes in experimental animal models, including neutrophil recruitment to the lung, the production of pro-inflammatory cytokines and chemokines, edema, and vascular permeability. In this review, we summarized these studies and described the anti-inflammatory activity of various plant extracts, such as Ginkgo biloba and Punica granatum, and such secondary metabolites as epigallocatechin-3-gallate and ellagic acid. In addition, we highlight the medical potential of these extracts and plant-derived compounds for treating of ALI.

A feedback loop in PPARγ-adenosine A2A receptor signaling inhibits inflammation and attenuates lung damages in a mouse model of LPS-induced acute lung injury

Although peroxisome proliferator-activated receptor-γ (PPARγ) and adenosine A2A receptor (A2AR) are reported to be anti-inflammatory factors in acute lung injury (ALI), their internal link and synergic or antagonistic effect after activation are poorly understood. Here, we found that PPARγ and A2AR could upregulate the mRNA and protein expressions of each other in lung tissues of LPS-induced mouse ALI model and murine macrophages. Further investigation demonstrated that PPARγ upregulated A2AR expression by directly binding to a DR10 response element (-218 to -197) within A2AR gene promoter region. Instead of directly interacting with PPARγ, A2AR stimulated PPARγ expression via protein kinase A (PKA)-cAMP response element binding protein (CREB) signaling by provoking the binding of CREB to a cAMP responsive element (CRE)-like site in PPARγ gene promoter region. In addition, combination of PPARγ and A2AR agonists was found to exert obviously better effect on suppressing neutrophil infiltration and inflammatory cytokine expressions, attenuating lung edema, pathological changes and improving lung function of blood gas exchange than their single application. These findings reveal a novel functional positive feedback loop between PPARγ and A2AR signaling to potentialize their effect on inhibiting inflammation and attenuating lung damages in ALI. It suggests that targeting this PPARγ-A2AR signaling rather than PPARγ or A2AR alone may be a more attractive and efficient potential therapeutic strategy for ALI.

Anti-inflammatory effects of escin are correlated with the glucocorticoid receptor/NF-κB signaling pathway, but not the COX/PGF2α signaling pathway

In China, escin has been widely used in the clinic as a potent anti-inflammatory drug. Previous studies have indicated that escin exerts its anti-inflammatory effect by enhancing the release of glucocorticoids (GCs) and prostaglandin-F2α (PGF2α), and this has been documented in the drug description. However, our previous studies demonstrated that escin did not increase the secretion of GCs, but instead elevated the protein expression of the GC receptor (GR), which may have repressed nuclear factor (NF)-κB-mediated gene expression. The aim of this study was to determine the functions of NF-κB and PGF2α with regard to the anti-inflammatory effect of escin. We investigated the anti-inflammatory effects of dexamethasone, diclofenac and escin against carrageenan-induced paw edema in rats, and observed that escin exerted a GC-like anti-inflammatory effect. In addition, we studied the role of PGF2α in the anti-inflammatory effect exerted by escin in an acetic acid-induced capillary permeability model in mice. The results revealed that the coadministration of escin and diclofenac, a potent prostaglandin-synthesis inhibitor, did not affect the anti-inflammatory effect of escin. Furthermore, we investigated the function of NF-κB with regard to the anti-inflammatory effect exerted by escin in lipopolysaccharide (LPS)-treated mice, and demonstrated that escin significantly inhibited the expression of NF-κB. These results suggest that escin has a GC-like anti-inflammatory effect, and that its mechanisms may be correlated with the GC receptor/NF-κB signaling pathway, but not the COX/PGF2α signaling pathway.

Protective effects of aerobic exercise on acute lung injury induced by LPS in mice

Introduction

The regular practice of physical exercise has been associated with beneficial effects on various pulmonary conditions. We investigated the mechanisms involved in the protective effect of exercise in a model of lipopolysaccharide (LPS)-induced acute lung injury (ALI).

Methods

Mice were divided into four groups: Control (CTR), Exercise (Exe), LPS, and Exercise + LPS (Exe + LPS). Exercised mice were trained using low intensity daily exercise for five weeks. LPS and Exe + LPS mice received 200 µg of LPS intratracheally 48 hours after the last physical test. We measured exhaled nitric oxide (eNO); respiratory mechanics; neutrophil density in lung tissue; protein leakage; bronchoalveolar lavage fluid (BALF) cell counts; cytokine levels in BALF, plasma and lung tissue; antioxidant activity in lung tissue; and tissue expression of glucocorticoid receptors (Gre).

Results

LPS instillation resulted in increased eNO, neutrophils in BALF and tissue, pulmonary resistance and elastance, protein leakage, TNF-alpha in lung tissue, plasma levels of IL-6 and IL-10, and IL-1beta, IL-6 and KC levels in BALF compared to CTR (P ≤0.02). Aerobic exercise resulted in decreases in eNO levels, neutrophil density and TNF-alpha expression in lung tissue, pulmonary resistance and elastance, and increased the levels of IL-6, IL-10, superoxide dismutase (SOD-2) and Gre in lung tissue and IL-1beta in BALF compared to the LPS group (P ≤0.04).

Conclusions

Aerobic exercise plays important roles in protecting the lungs from the inflammatory effects of LPS-induced ALI. The effects of exercise are mainly mediated by the expression of anti-inflammatory cytokines and antioxidants, suggesting that exercise can modulate the inflammatory-anti-inflammatory and the oxidative-antioxidative balance in the early phase of ALI.

Potent anti-inflammatory agent escin does not affect the healing of tibia fracture and abdominal wound in an animal model

Escin, a potent anti-inflammatory and anti-edematous agent, has been widely used clinically in preventing inflammatory edema after trauma, such as fracture and surgery. The aim of this study was to investigate whether escin has an inhibitory effect on fracture healing, and whether escin has an inhibitory effect on wound healing after surgery. Male New Zealand white rabbits underwent tibial mid-diaphyseal osteotomy, and were administered escin once per day for 10 days. At weeks 2, 4 and 6, bone fracture healing and bone mineral density were measured. The histologic examination of callus, osteocalcin, alkaline phosphatase, calcium and phosphate in the serum were also assayed. In another experiment, the rats underwent midline laparotomy, and received escin once prior to or after the operation. Six days later, the abdominal incision wounds were excised for measuring hydroxyproline levels. The results showed that there were no significant differences in fracture healing between the model and rabbits administered escin, and escin did not affect the hydroxyproline levels in the abdominal incision wounds of the rats. These findings suggest that escin has no inhibitory effect on fracture and wound healing in animal models.