Ginsenoside compound-K inhibits the activity of B cells through inducing IgD-B cell receptor endocytosis in mice with collagen-induced arthritis

Multi-layered effects of Panax notoginseng on immune system

Recent research has demonstrated the immunomodulatory potential of Panax notoginseng in the treatment of chronic inflammatory diseases and cerebral hemorrhage, suggesting its significance in clinical practice. Nevertheless, the complex immune activity of various components has hindered a comprehensive understanding of the immune-regulating properties of Panax notoginseng, impeding its broader utilization. This review evaluates the effect of Panax notoginseng to various types of white blood cells, elucidates the underlying mechanisms, and compares the immunomodulatory effects of different Panax notoginseng active fractions, aiming to provide the theory basis for future immunomodulatory investigation.

Rare ginsenosides: A unique perspective of ginseng research

BACKGROUND

Rare ginsenosides (Rg3, Rh2, C-K, etc.) refer to a group of dammarane triterpenoids that exist in low natural abundance, mostly produced by deglycosylation or side chain modification via physicochemical processing or metabolic transformation in gut, and last but not least, exhibited potent biological activity comparing to the primary ginsenosides, which lead to a high concern in both the research and development of ginseng and ginsenoside-related nutraceutical and natural products. Nevertheless, a comprehensive review on these promising compounds is not available yet.

AIM OF REVIEW

In this review, recent advances of Rare ginsenosides (RGs) were summarized dealing with the structurally diverse characteristics, traditional usage, drug discovery situation, clinical application, pharmacological effects and the underlying mechanisms, structure-activity relationship, toxicity, the stereochemistry properties, and production strategies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

A total of 144 RGs with diverse skeletons and bioactivities were isolated from Panax species. RGs acted as natural ligands on some specific receptors, such as bile acid receptors, steroid hormone receptors, and adenosine diphosphate (ADP) receptors. The RGs showed promising bioactivities including immunoregulatory and adaptogen-like effect, anti-aging effect, anti-tumor effect, as well as their effects on cardiovascular and cerebrovascular system, central nervous system, obesity and diabetes, and interaction with gut microbiota. Clinical trials indicated the potential of RGs, while high quality data remains inadequate, and no obvious side effects was found. The stereochemistry properties induced by deglycosylation at C (20) were also addressed including pharmacodynamics behaviors, together with the state-of-art analytical strategies for the identification of saponin stereoisomers. Finally, the batch preparation of targeted RGs by designated strategies including heating or acid/ alkaline-assisted processes, and enzymatic biotransformation and biosynthesis were discussed. Hopefully, the present review can provide more clues for the extensive understanding and future in-depth research and development of RGs, originated from the worldwide well recognized ginseng plants.

Ginsenoside compound K exerts anti-inflammatory effects through transcriptional activation and transcriptional inhibition of glucocorticoid receptor in rheumatoid arthritis fibroblast-like synoviocytes

Ginsenoside compound K (GCK) has anti-inflammatory and immunoregulatory effects, and glucocorticoid receptor (GR) has been considered as its potential target. But the mechanism by which GCK exerts its anti-inflammatory effects after GR activation remains unclear. In this study, molecular docking, isothermal titration calorimetry, siRNA of GR and GRA458T mutation were used to confirm the anti-inflammatory mechanism of GCK targeting GR in fibroblast-like synoviocytes (FLS). The results showed that the key binding sites of GR and GCK were identified as ASN564, MET560 and ASN638, with binding levels at the μm level. In addition, the inhibitory effect of GCK on the proliferation of FLS and the secretion of inflammatory cytokines (IL-6, IL-8, and IL-1β) were mediated by transcriptional activation of GR, but on the migration, invasion, and TNF-α secretion of FLS were mediated by transcriptional inhibition of GR. These actions exert anti-inflammatory effects through indirect and direct inhibition of NF-κB transcriptional activity, respectively. In conclusion, this study elucidates that GCK can directly bind to and activate GR. Furthermore, after activation, GR mediates the anti-inflammatory effects of GCK through two mechanisms: transcriptional activation and transcriptional inhibition.

New perspective on the immunomodulatory activity of ginsenosides: Focus on effective therapies for post-COVID-19

More than 700 million confirmed cases of Coronavirus Disease-2019 (COVID-19) have been reported globally, and 10-60% of patients are expected to exhibit "post-COVID-19 symptoms," which will continue to affect human life and health. In the absence of safer, more specific drugs, current multiple immunotherapies have failed to achieve satisfactory efficacy. Ginseng, a traditional Chinese medicine, is often used as an immunomodulator and has been used in COVID-19 treatment as a tonic to increase blood oxygen saturation. Ginsenosides are the main active components of ginseng. In this review, we summarize the multiple ways in which ginsenosides affect post-COVID-19 symptoms, including inhibition of lipopolysaccharide, tumor necrosis factor signaling, modulation of chemokine receptors and inflammasome activation, induction of macrophage polarization, effects on Toll-like receptors, nuclear factor kappa-B, the mitogen-activated protein kinase pathway, lymphocytes, intestinal flora, and epigenetic regulation. Ginsenosides affect virus-mediated tissue damage, local or systemic inflammation, immune modulation, and other links, thus alleviating respiratory and pulmonary symptoms, reducing the cardiac burden, protecting the nervous system, and providing new ideas for the rehabilitation of patients with post-COVID-19 symptoms. Furthermore, we analyzed its role in strengthening body resistance to eliminate pathogenic factors from the perspective of ginseng-epidemic disease and highlighted the challenges in clinical applications. However, the benefit of ginsenosides in modulating organismal imbalance post-COVID-19 needs to be further evaluated to better validate the pharmacological mechanisms associated with their traditional efficacy and to determine their role in individualized therapy.

Triterpenes as Potential Drug Candidates for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by joint inflammation, swelling and pain. Although RA mainly affects the joints, the disease can also have systemic implications. The presence of autoantibodies, such as anti-cyclic citrullinated peptide antibodies and rheumatoid factors, is a hallmark of the disease. RA is a significant cause of disability worldwide associated with advancing age, genetic predisposition, infectious agents, obesity and smoking, among other risk factors. Currently, RA treatment depends on anti-inflammatory and disease-modifying anti-rheumatic drugs intended to reduce joint inflammation and chronic pain, preventing or slowing down joint damage and disease progression. However, these drugs are associated with severe side effects upon long-term use, including immunosuppression and development of opportunistic infections. Natural products, namely triterpenes with anti-inflammatory properties, have shown relevant anti-arthritic activity in several animal models of RA without undesirable side effects. Therefore, this review covers the recent studies (2017-2022) on triterpenes as safe and promising drug candidates for the treatment of RA. These bioactive compounds were able to produce a reduction in several RA activity indices and immunological markers. Celastrol, betulinic acid, nimbolide and some ginsenosides stand out as the most relevant drug candidates for RA treatment.

Compound K-An immunomodulator of macrophages in inflammation

Compound K (CK) is a secondary ginsenoside biotransformed from ginseng. This review discusses the function of CK as a potential ligand of the glucocorticoid receptor and a regulator of macrophage inflammatory responses. We provide findings on the ability of CK to inhibit the activation of M1 macrophages and promote the activation and differentiation of M2 macrophages. In addition, the effect of inhibiting the inflammasome response was collected. We summarized the evidences that CK is effective in the treatment of various inflammatory diseases such as rheumatoid arthritis, systemic lupus erythematosus, dermatitis, asthma, chronic obstructive pulmonary disease, sepsis associated encephalopathy, atherosclerosis, inflammatory bowel disease, and diabetes. These findings suggest the potential of CK as a therapeutic agent that can resolve inflammation and restore homeostasis.

A novel GRK2 inhibitor alleviates experimental arthritis through restraining Th17 cell differentiation

T helper type 17 (Th17) cell which is induced by interleukine-6 (IL-6)-signal transducers and activators of transcription 3 (STAT3) signaling is a central pro-inflammatory T cell subtype in rheumatoid arthritis (RA) and could be significantly reduced by paeoniflorin-6'-O-benzene sulfonate (CP-25) treatment with unclear mechanisms. This study was aimed to found out the mechanism of CP-25 in hampering Th17 cells differentiation in arthritic animals thus explore more therapeutic targets for RA. In mice with collagen-induced arthritis (CIA), both circulating and splenic Th17 subsets were expanded with increased STAT3 phosphorylation and decreased Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP1)-β-arrestin2 (arrb2)-STAT3 interaction in CD4⁺ helper T (Th) cells. Either CP-25 or paroxetine (PAR), an established G protein coupled receptor kinase 2 (GRK2) inhibitor treatment effectively relieved the joints inflammation of CIA mice with substantially reduced Th17 cell population through inhibiting STAT3 and restoring the SHP1-arrb2-STAT3 complex. Knockout of arrb2 exacerbated the clinical manifestations of collagen antibody-induced arthritis with upregulated Th17 cells. In vitro studies revealed that depletion of arrb2 or inhibition of SHP1 promoted Th17 cell differentiation. Moreover, stimulation of adenosine A₃ receptor (A₃AR) simultaneously promoted Th17 cell differentiation via accelerating abbr2-A₃AR binding, which could be prevented through inhibiting GRK2 phosphorylation by CP-25 or PAR, or genetically reducing GRK2. This work has demonstrated that CP-25 or PAR treatment recovers the SHP1-arrb2-STAT3 complex which prevents STAT3 activation in Th cells through reducing arrb2 recruitment to A₃AR by inhibiting GRK2 phosphorylation, leading to the reduction in Th17 cell differentiation and arthritis attenuation.

Regulating Th17/Treg Balance Contributes to the Therapeutic Effect of Ziyuglycoside I on Collagen-Induced Arthritis

To investigate the therapeutic effect and primary pharmacological mechanism of Ziyuglycoside I (Ziyu I) on collagen-induced arthritis (CIA) mice. CIA mice were treated with 5, 10, or 20 mg/kg of Ziyu I or 2 mg/kg of methotrexate (MTX), and clinical manifestations, as well as pathological changes, were observed. T cell viability and subset type were determined, and serum levels of transforming growth factor-beta (TGF-β) and interleukin-17 (IL-17) were detected. The mRNA expression of retinoid-related orphan receptor-γt (RORγt) and transcription factor forkhead box protein 3 (Foxp3) in mouse spleen lymphocytes was ascertained by the real-time reverse transcriptase-polymerase chain reaction (RT-qPCR). Molecular docking was used to detect whether there was a molecular interaction between Ziyu I and protein kinase B (Akt). The activation of mechanistic target of rapamycin (mTOR) in T cells was verified by Western blotting or immunofluorescence. Ziyu I treatment effectively alleviated arthritis symptoms of CIA mice, including body weight, global score, arthritis index, and a number of swollen joints. Similarly, pathological changes of joints and spleens in arthritic mice were improved. The thymic index, T cell activity, and RORγt production of Ziyu I-treated mice were significantly reduced. Notably, through molecular docking, western blotting, and immunofluorescence data analysis, it was found that Ziyu I could interact directly with Akt to reduce downstream mTOR activation and inhibit helper T cell 17 (Th17) differentiation, thereby regulating Th17/regulatory T cell (Treg) balance and improving arthritis symptoms. Ziyu I effectively improves arthritic symptoms in CIA mice by inhibiting mTOR activation, thereby affecting Th17 differentiation and regulating Th17/Treg balance.

Ziyuglycoside I attenuates collagen-induced arthritis through inhibiting plasma cell expansion

ETHNOBOTANICAL RELEVANCE

With most of the anti-rheumatic drugs having severe adverse drug reactions and poor tolerance, the active components from natural herbs provides a repository for novel, safe, and effective drug development. Sanguisorba officinalis L. exhibits definite anti-inflammatory capacity, however, whether it has anti-rheumatic effects has not been revealed.

AIM OF THE STUDY

In the present study, the effect of Ziyuglycoside I (Ziyu I), one of the most important active components in Sanguisorba officinalis L., was investigated in treating collagen-induced arthritis (CIA), illuminating its potential pharmacological mechanisms.

MATERIAL AND METHODS

CIA mice were treated with 5, 10, or 20 mg/kg of Ziyu I or 2 mg/kg of MTX, and clinical manifestations as well as pathological changes were observed. T and B cell viability was determined using cell counting kit-8, plasma autoantibodies and cytokines were tested with ELISA, T and B cell subsets were identified by flow cytometry, Blimp1 expression was detected by RT-qPCR and in situ immunofluorescence. The expression of activation-induced cytidine deaminase (AID) was detected by immunohistochemistry. ERK activation in B cells was verified through western blotting and immunofluorescence. Meanwhile, bioinformatics retrieval and molecular docking/molecular dynamics were used to predict the relationship between Blimp1, ERK and Ziyu I with the pharmacokinetics and toxicity of Ziyu I being evaluated in the ADMETlab Web platform.

RESULTS

Ziyu I treatment effectively alleviated the joint inflammatory manifestation including arthritis index, global scores, swollen joint count and body weight of CIA mice. It improved the pathological changes of joint and spleen of arthritic mice, especially in germinal center formation. Ziyu I displayed a moderate regulatory effect on T cell activation, the percentage of total T and helper T cells, and tumor necrosis factor-α, but transforming growth factor-β was not restored. Increased spleen index, B cell viability and plasma auto-antibody production in CIA mice were significantly reduced by Ziyu I therapy. Of note, we found that Ziyu I administration substantially inhibited the excessive expansion of plasma cells in spleen through preventing the expression of B lymphocyte induced maturation protein 1 (Blimp1) and AID in B cells. Ziyu I was predicted in silico to directly interact with ERK2, and reduce ERK2 activation, contributing to the depressed expression of Blimp1. Moreover, Ziyu I was predicted to have a favorable pharmacokinetic profile and low toxicity.

CONCLUSION

Ziyu I effectively ameliorates CIA in mice by inhibiting plasma cell generation through prevention of ERK2-mediated Blimp1 expression in B cells. Therefore, Ziyu I is a promising candidate for anti-arthritic drug development.

Natural medicines of targeted rheumatoid arthritis and its action mechanism

Rheumatoid arthritis (RA) is an autoimmune disease involving joints, with clinical manifestations of joint inflammation, bone damage and cartilage destruction, joint dysfunction and deformity, and extra-articular organ damage. As an important source of new drug molecules, natural medicines have many advantages, such as a wide range of biological effects and small toxic and side effects. They have become a hot spot for the vast number of researchers to study various diseases and develop therapeutic drugs. In recent years, the research of natural medicines in the treatment of RA has made remarkable achievements. These natural medicines mainly include flavonoids, polyphenols, alkaloids, glycosides and terpenes. Among them, resveratrol, icariin, epigallocatechin-3-gallate, ginsenoside, sinomenine, paeoniflorin, triptolide and paeoniflorin are star natural medicines for the treatment of RA. Its mechanism of treating RA mainly involves these aspects: anti-inflammation, anti-oxidation, immune regulation, pro-apoptosis, inhibition of angiogenesis, inhibition of osteoclastogenesis, inhibition of fibroblast-like synovial cell proliferation, migration and invasion. This review summarizes natural medicines with potential therapeutic effects on RA and briefly discusses their mechanisms of action against RA.

Ginsenoside compound K- a potential drug for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory and autoimmune disease, if prescription of effective delayed, the articular disturbances may lead to disability. Ginsenoside compound K (GCK) is the main degradation product of oral ginsenosides in the human intestine. Numerous researches in vitro and in vivo have recorded the anti-arthritic effect of GCK, we discuss the mechanisms from the following three aspects, including anti-inflammatory, immune-regulatory, and bone-protective, respectively, in this review, and the anti-arthritic mechanism of GCK may be related to the effect on TNF-α-TNFR2, glucocorticoid receptor (GR) and β-arrestin1/2. We also describe the anti-anemia effect of GCK to open the possibility that GCK can be used as an effective disease-modifying anti-rheumatic drug (DMARD).

Combination therapy of ginsenoside compound K and methotrexate was efficient in elimination of anaemia and reduction of disease activity in adjuvant-induced arthritis rats

CONTEXT

Ginsenoside compound K (CK) has anti-inflammatory, immunoregulatory, and myelosuppressive protective effects. Methotrexate (MTX) is widely used in combination therapy for rheumatoid arthritis (RA).

OBJECTIVE

To evaluate the effects of combination therapy of CK and MTX on anaemia and anti-arthritis in adjuvant-induced arthritis (AA) rats.

MATERIALS AND METHODS

AA was induced in rats by Complete Freund's adjuvant, and divided into five groups (n = 10): normal, AA, CK 80 mg/kg, combination therapy (80 mg/kg CK combined with 0.5 mg/kg MTX), and MTX 0.5 mg/kg. From day 12, CK (once a day for 15 days) or MTX (once every 3 days, five times) were intragastrically administered.

RESULTS

Combination therapy showed increased haemoglobin to 148.5 ± 10.1 g/L compared with AA (129.8 ± 11.7 g/L) and MTX (128.8 ± 18.4 g/L), and decreased reticulocytes in peripheral blood to 4.9 ± 1.1% compared with MTX (9.3 ± 3.3%). In combination therapy group, paw swelling decreased to 5.6 ± 4.3 mL compared with CK (9.4 ± 3.9 mL) and MTX (13.5 ± 7.4 mL), and swollen joint count decreased to 1.4 ± 0.8 compared with CK (2.1 ± 1.0) and MTX (2.4 ± 1.2) at day 24. Combination therapy showed decreased IL-6 to 25.1 ± 17.2 pg/mL compared with MTX (44.9 ± 4.8 pg/mL), and decreased IL-17 to 5.8 ± 3.9 pg/mL compared with MTX (10.7 ± 4.2 pg/mL).

CONCLUSION

The anti-anaemia effect of CK deserves further study, and CK can be a candidate effective drug for combined treatment in RA with anaemia.

Sustaining Circulating Regulatory T Cell Subset Contributes to the Therapeutic Effect of Paroxetine on Mice With Diabetic Cardiomyopathy

BACKGROUND

G protein coupled receptor kinase 2 (GRK2) inhibitor, paroxetine, has been approved to ameliorate diabetic cardiomyopathy (DCM). GRK2 is also involved in regulating T cell functions; the potential modifications of paroxetine on the immune response to DCM is unclear.

METHODS AND RESULTS

DCM mouse was induced by high-fat diet (HFD) feeding. A remarkable reduction in the regulatory T (Treg) cell subset in DCM mouse was found by flow cytometry, with impaired cardiac function evaluated by echocardiography. The inhibited Treg differentiation was attributable to insulin chronic stimulation in a GRK2-PI3K-Akt signaling-dependent manner. The selective GRK2 inhibitor, paroxetine, rescued Treg differentiation in vitro and in vivo. Furthermore, heart function, as well as the activation of excitation-contraction coupling proteins such as phospholamban (PLB) and troponin I (TnI) was effectively promoted in paroxetine-treated DCM mice compared with vehicle-treated DCM mice. Blockade of FoxP3 expression sufficiently inhibited the proportion of Treg cells, abolished the protective effect of paroxetine on heart function as well as PLB and TnI activation in HFD-fed mice. Neither paroxetine nor carvedilol could effectively ameliorate the metabolic disorder of HFD mice.

CONCLUSIONS

The impaired systolic heart function of DCM mice was effectively improved by paroxetine therapy, partially through restoring the population of circulating Treg cells by targeting the GRK2-PI3K-Akt pathway.

Genome-scale CRISPR screening for potential targets of ginsenoside compound K

Ginsenosides exhibit a large variety of biological activities in maintaining physical health; however, the molecule underpinnings underlining these biological activities remain to be defined. Here, we took a cellular condition that compound K (CK) induces autophagic cell death in HeLa cells, and setup a high-throughput genetic screening using CRISPR technology. We have identified a number of CK-resistant and CK-sensitive genes, and further validated PMAIP1 as a CK-resistant gene and WASH1 as a CK-sensitive gene. Compound K treatment reduces the expression of WASH1, which further accelerates the autophagic cell death, highlighting WASH1 as an interesting downstream mediator of CK effects. Overall, our study offers an easy-to-adopt platform to study the functional mediators of ginsenosides, and provides a candidate list of genes that are potential targets of CK.