Celastrol inhibits lung infiltration in differential syndrome animal models by reducing TNF-α and ICAM-1 levels while preserving differentiation in ATRA-induced acute promyelocytic leukemia cells

Multi-target mechanism of Tripteryguim wilfordii Hook for treatment of ankylosing spondylitis based on network pharmacology and molecular docking

BACKGROUND

Tripteryguim wilfordii Hook (TWH) has significant anti-inflammatory and immunosuppressive properties and is widely used for treating autoimmune and inflammatory diseases. However, the multi-target mechanism of TWH on ankylosing spondylitis (AS) remains to be elucidated.

METHODS

Active components and their target proteins were screened from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Meanwhile, AS-related targets were obtained from the Genecards Database. After overlapping, the targets of TWH against AS were collected. Then protein-protein interaction (PPI) network and core targets analysis were conducted through STRING network platform and Cytoscape software. Moreover, molecular docking methods were utilized to confirm the high affinity between TWH and targets. Finally, DAVID online tool was used to perform gene ontology (GO) and Kyoto encyclopaedia of genes and genome (KEGG) pathway enrichment analysis of overlapping targets.

RESULTS

The TCMSP Database results showed that there were11 active components of TWH against AS. PPI network and core targets analysis suggested that ESR1, VEGF, ICAM-1, and RELA were key targets against AS. Moreover, molecular docking methods confirmed the high affinity between bioactive molecular of TWH and their targets in AS. At last, enrichment analysis indicated that TWH participates in various biological processes, such as cell-cell adhesion, regulation of cell-matrix adhesion, acute inflammatory response, via TNF-α, NF-κB and so forth signalling pathways.

CONCLUSION

Verified by network pharmacology approach based on data mining and molecular docking methods, multi-target drug TWH may serve as a promising therapeutic candidate for AS but still needs further in vivo/in vitro experiments.

Celastrol alleviates LPS-induced inflammation in BMDMs and acute lung injury in mice via inhibition of p-38 MAPK/MK2 signaling

Objective:

Celastrol is a compound extracted from a medicinal plant Tripterygium wilfordii which has a broad-spectrum anti-inflammatory effect in traditional medicine. However, the effect of celastrol on acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is still unknown.

Methods:

We reported that celastrol alleviated LPS-induced acute lung injury by H&E staining, MPO activity and the expression of cytokines in broncho-alveolar lavage fluid. The effect of celastrol on bone marrow-derived macrophages (BMDMs) after LPS treatment was measured by ELISA and Western blotting.

Results:

In vivo, celastrol reduced the LPS-induced lung edema and MPO activity of lung tissue. Furthermore, the production of inflammatory cytokines IL-6, TNF-α, and KC in bronchoalveolar lavage was reduced. In vitro, upon treatment of LPS, celastrol dose-dependently inhibited the expression of iNOS in BMDMs. Meanwhile, the expression of IL-6, TNF-α, and KC in BMDMs were also inhibited by celastrol treatment. Furthermore, we found that celastrol attenuated the phosphorylation of p38 MAPK and MK2, and inhibited the interaction between p38 MAPK and MK2.

Conclusion:

Our data indicate that celastrol has an anti-inflammatory effect on LPS-induced inflammatory response in vivo and in vitro, suggesting celastrol is a promising compound for the treatment of ALI and ARDS.

Therapeutic targets of thunder god vine (Tripterygium wilfordii hook) in rheumatoid arthritis (Review)

Celastrol and triptolide, chemical compounds isolated from Tripterygium wilfordii hook (also known as thunder god vine), are effective against rheumatoid arthritis (RA). Celastrol targets numerous signaling pathways involving NF‑κB, endoplasmic reticulum Ca2+‑ATPase, myeloid differentiation factor 2, toll‑like receptor 4, pro‑inflammatory chemokines, DNA damage, cell cycle arrest and apoptosis. Triptolide, inhibits NF‑κB, the receptor activator of NF‑κB (RANK)/RANK ligand/osteoprotegerin signaling pathway, cyclooxygenase‑2, matrix metalloproteases and cytokines. The present review examined the chemistry and bioavailability of celastrol and triptolide, and their molecular targets in treating RA. Clinical studies have demonstrated that T. wilfordii has several promising bioactivities, but its multi‑target toxicity has restricted its application. Thus, dosage control and structural modification of T. wilfordii are required to reduce the toxicity. In this review, future directions for research into these promising natural products are discussed.

Metabolomics Reveals that Cysteine Metabolism Plays a Role in Celastrol-Induced Mitochondrial Apoptosis in HL-60 and NB-4 Cells

Recently, celastrol has shown great potential for inducing apoptosis in acute myeloid leukemia cells, especially acute promyelocytic leukaemia cells. However, the mechanism is poorly understood. Metabolomics provides an overall understanding of metabolic mechanisms to illustrate celastrol's mechanism of action. We treated both nude mice bearing HL-60 cell xenografts in vivo and HL-60 cells as well as NB-4 cells in vitro with celastrol. Ultra-performance liquid chromatography coupled with mass spectrometry was used for metabolomics analysis of HL-60 cells in vivo and for targeted L-cysteine analysis in HL-60 and NB-4 cells in vitro. Flow cytometric analysis was performed to assess mitochondrial membrane potential, reactive oxygen species and apoptosis. Western blotting was conducted to detect the p53, Bax, cleaved caspase 9 and cleaved caspase 3 proteins. Celastrol inhibited tumour growth, induced apoptosis, and upregulated pro-apoptotic proteins in the xenograft tumour mouse model. Metabolomics showed that cysteine metabolism was the key metabolic alteration after celastrol treatment in HL-60 cells in vivo. Celastrol decreased L-cysteine in HL-60 cells. Acetylcysteine supplementation reversed reactive oxygen species accumulation and apoptosis induced by celastrol and reversed the dramatic decrease in the mitochondrial membrane potential and upregulation of pro-apoptotic proteins in HL-60 cells. In NB-4 cells, celastrol decreased L-cysteine, and acetylcysteine reversed celastrol-induced reactive oxygen species accumulation and apoptosis. We are the first to identify the involvement of a cysteine metabolism/reactive oxygen species/p53/Bax/caspase 9/caspase 3 pathway in celastrol-triggered mitochondrial apoptosis in HL-60 and NB-4 cells, providing a novel underlying mechanism through which celastrol could be used to treat acute myeloid leukaemia, especially acute promyelocytic leukaemia.

Protective effect of celastrol on myocardial ischemia-reperfusion injury

OBJECTIVE

Celastrol, a major active constituent of Tripterygium wilfordii, has antioxidant, anti-inflammatory, and anticancer effects. However, whether celastrol can exert protective effect on myocardial ischemia-reperfusion injury (MIRI) is unknown. The aim of this study was to test the protective effect of celastrol on MIRI and elucidate its underlying mechanism.

METHODS

Cardiomyocytes (H9c2 cells) were subjected to hypoxia for 8 h followed by reoxygenation for 4 h to create hypoxia/reoxygenation (H/R) model, an in vitro MIRI model. Celastrol was added to the medium 60 min before the H/R process . Cell viability was detected using MTT assay. Myocardial injury was evaluated by measuring lactate dehydrogenase (LDH) and creatine kinase MB isoenzyme (CK-MB) activity. Changes in mRNA and protein expression of TNF-α, IL-1ß, and nuclear factor-K B (NF-K B) were measured with RT-qPCR assay and western blot analysis.

RESULTS

Results showed that low-dose celastrol (20 and 50 nM) treatment significantly increased cell viability and decreased LDH and CK-MB activity in the condition of H/R, but high-dose celastrol (200 and 400 nM) resulted in extra injury to cardiomyocytes. Moreover, treatment with 50 nM celastrol significantly downregulated mRNA and protein expression of TNF-α and IL-1ß. Meanwhile, NF-K B mRNA and protein in the nucleus were also correspondingly reduced.

CONCLUSION

Our study demonstrated that low-dose celastrol could prevent MIRI in cardiomyocytes by inhibiting the activation of NF-K B, and celastrol may be a potential therapeutic agent for preventing MIRI.

Celastrol attenuates impairments associated with lipopolysaccharide-induced acute respiratory distress syndrome (ARDS) in rats

Celastrol, a constituent from a traditional Chinese medicinal herb belonging to the family Celastraceae, has been shown to impart anti-inflammatory properties, in part, by inhibiting NF-κB activity and related induction of pro-inflammatory cytokine formation/release. The present study investigated the effects of celastrol in an animal model of acute respiratory distress syndrome (ARDS) induced by intratracheal administration of lipopolysaccharides (LPSs). Celastrol pre-treatment groups received celastrol by intraperitoneal injection on seven consecutive days before LPS treatment. In rats evaluated 24 h after LPS administration, oxygenation indices and lung injury were measured, as were levels of inflammatory cells and cytokines in isolated bronchoalveolar lavage fluid (BALF). Lung tissue expression of proteins involved in NF-κB and ERK/MAPK pathways were measured by Western blot analyses. Celastrol pre-treatments appeared to attenuate LPS-induced lung injury and inflammatory responses in the rats, including decreases in inducible aggregation\infiltration of inflammatory cells and production/release of pro-inflammatory cytokines into the lung airways. Celastrol appeared to also inhibit NF-κB activation, but had no effect on ERK/MAPK pathways in the LPS-induced ARDS. The results here thus indicated that celastrol pre-treatment could impart protective effects against LPS-induced ARDS, and that these effects may be occurring through an inhibition of induction of NF-κB signaling pathways.

HMGB1 promotes differentiation syndrome by inducing hyperinflammation via MEK/ERK signaling in acute promyelocytic leukemia cells

Differentiation therapy based on all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) for the treatment of acute promyelocytic leukemia (APL) is complicated by the development of differentiation syndrome (DS), which can be fatal. We examined the role of HMGB1 (high-mobility group box 1) in DS using both in vitro and in vivo models. HMGB1 and the pro-inflammatory cytokines IL-1β and TNF-α were gradually released from NB4 and HL-60 cells treated with ATRA and/or ATO. Similarly, higher serum HMGB1 levels positively correlated with the clinical status of DS patients. Exogenous HMGB1 promoted rapid release of IL-1β and TNF-α as well as elevated expression of ICAM-1, without altering cell differentiation. Exogenous HMGB1 also enhanced pulmonary infiltration and up-regulated ICAM-1 expression in the ATRA-treated DS mouse. Pharmacological inhibition or depletion of MEK1/2 reduced the cytokine levels and suppressed expression of ICAM-1 and the adhesion of HMGB1-treated NB4 cells to endothelial cells, implicating MEK/ERK signaling in the response to HMGB1 during DS. Treatment with a HMGB1-neutralizing antibody reduced secretion of TNF-α and IL-1β, arrested the elevation of ICAM-1 and blunted the activation of ERK1/2 in ATRA-induced NB4 cells. The HMGB1-neutralizing antibody also decreased ICAM-1 expression and reduced mortality in ATRA-treated DS model mice. These findings demonstrate that released HMGB1 is central to DS, and that targeting HMGB1 may be of therapeutic value in the treatment of DS.

A Mechanistic Overview of Triptolide and Celastrol, Natural Products from Tripterygium wilfordii Hook F

Triptolide and celastrol are predominantly active natural products isolated from the medicinal plant Tripterygium wilfordii Hook F. These compounds exhibit similar pharmacological activities, including anti-cancer, anti-inflammation, anti-obesity, and anti-diabetic activities. Triptolide and celastrol also provide neuroprotection and prevent cardiovascular and metabolic diseases. However, toxicity restricts the further development of triptolide and celastrol. In this review, we comprehensively review therapeutic targets and mechanisms of action, and translational study of triptolide and celastrol. We systemically discuss the structure-activity-relationship of triptolide, celastrol, and their derivatives. Furthermore, we propose the use of structural derivatives, targeted therapy, and combination treatment as possible solutions to reduce toxicity and increase therapeutic window of these potent natural products from T. wilfordii Hook F.