Stachydrine suppresses viability & migration of astrocytoma cells via CXCR4/ERK & CXCR4/Akt pathway activity

Exploring stachydrine: from natural occurrence to biological activities and metabolic pathways

Stachydrine, also known as proline betaine, is a prominent constituent of traditional Chinese herb Leonurus japonicus, renowned for its significant pharmacological effects. Widely distributed in plants like Leonurus and Citrus aurantium, as well as various bacteria, stachydrine serves pivotal physiological functions across animal, plant, and bacterial kingdoms. This review aims to summarizes diverse roles and mechanisms of stachydrine in addressing cardiovascular and cerebrovascular diseases, neuroprotection, anticancer activity, uterine regulation, anti-inflammatory response, obesity management, and respiratory ailments. Notably, stachydrine exhibits cardioprotective effects via multiple pathways encompassing anti-inflammatory, antioxidant, anti-apoptotic, and modulation of calcium handling functions. Furthermore, its anti-cancer properties inhibit proliferation and migration of numerous cancer cell types. With a bi-directional regulatory effect on uterine function, stachydrine holds promise for obstetrics and gynecology-related disorders. In plants, stachydrine serves as a secondary metabolite, contributing to osmotic pressure regulation, nitrogen fixation, pest resistance, and stress response. Similarly, in bacteria, it plays a crucial osmoprotective role, facilitating adaptation to high osmotic pressure environments. This review also addresses ongoing research on the anabolic metabolism of stachydrine. While the biosynthetic pathway remains incompletely understood, the metabolic pathway is well-established. A deeper understanding of stachydrine biosynthesis holds significance for elucidating its mechanism of action, advancing the study of plant secondary metabolism, enhancing drug quality control, and fostering new drug development endeavors.

Stachydrine represses the proliferation and enhances cell cycle arrest and apoptosis of breast cancer cells via PLA2G2A/DCN axis

Considering the therapeutic efficacy of Stachydrine on breast cancer (BC), this study aims to decipher the relevant mechanism. The effects of Stachydrine on BC cell viability, proliferation and apoptosis were firstly investigated. Then, Bioinformatics was applied to sort out the candidate interacting with Stachydrine as well as its expression and downstream target in BC. Relative expressions of genes of interest as well as proliferation- and apoptosis-related factors in BC cells were quantified through quantitative reverse-transcription PCR and western blot as appropriate. As a result, Stachydrine inhibited the proliferation, down-regulated the expressions of proliferating cell nuclear antigen and CyclinD1, enhanced cell cycle arrest and apoptosis, and up-regulated the levels of Cleaved caspase-3 and Cleaved caspase-9 in BC cells. Phospholipase A2 Group IIA (PLA2G2A) was predicted as the candidate interacting with Stachydrine and to be lowly expressed in BC. PLA2G2A silencing reversed while PLA2G2A overexpression reinforced the effects of Stachydrine. Decorin (DCN) was the downstream target of PLA2G2A and also lowly expressed in BC. PLA2G2A silencing counteracted yet overexpressed PLA2G2A strengthened the promoting effects of Stachydrine on DCN level. Collectively, Stachydrine inhibits the growth of BC cells to promote cell cycle arrest and apoptosis via PLA2G2A/DCN axis.

Synthesis, characterization and anti-breast cancer activities of stachydrine derivatives

Stachydrine is a hydrophilic quaternary amine salt with good antitumor effect, but its application is limited due to its rapid metabolism and low bioavailability. We synthesized and evaluated nine prodrugs of stachydrine, which showed suitable hydrophobicity (CLogP: -2.58-4.78, vs SS-0: -3.32) and better in vitro anticancer activity (IC50: 0.34 μM-14.03 mM, vs SS-0: 38.97 mM-147.19 mM) in comparison with stachydrine. Among them, SS-12, SS-16 and SS-18 are the most effective compounds against 4T1 cells, and the IC50 is 2.15-24.14 μM. Especially, compared with stachydrine, SS-12 significantly blocked the cell cycle in the G0/G1 phase, reduced the mitochondrial membrane potential, and induced the apoptosis of 4T1 cells through mitochondria pathway, which increased the expressions of Bax and cleaved caspase-3 protein, decrease the expression of Bcl-2. The pharmacokinetics of SS-12 showed a rational bioavailability (79.6%), and a longer retention time (T1/2 = 7.62 h) than that of stachydrine (T1/2 ≈ 1.16 h) in rats. Compared with stachydrine, SS-12 significantly enhanced the anticancer efficacy (56.32% of tumor-inhibition rates, vs SS-0: 3.89%), meanwhile, ameliorated the tumor-induced organ damage in mice. Therefore, SS-12 may be a promising prodrug of stachydrine against breast cancer.

Stachydrine is effective and selective against blast phase chronic myeloid leukaemia through inhibition of multiple receptor tyrosine kinases

CONTEXT

Resistance to BCR-ABL tyrosine kinase inhibitor (TKI) is the cause of treatment failure in blast phase chronic myeloid leukaemia (BP-CML). Agents that act synergistically with BCR-ABL TKI are required to improve response.

OBJECTIVE

This work investigated the effects of stachydrine in CML.

MATERIALS AND METHODS

CML cells were treated with control or stachydrine at 20, 40 and 80 µM. Proliferation and apoptosis were examined after 72 h treatment. Combination studies were performed in four groups: control, TKI, stachydrine and the combination of stachydrine and TKI. Immunoblotting analysis was performed in CML cells after 24 h treatment.

RESULTS

Stachydrine inhibited K562 (IC₅₀ 61 µM), KCL22 (IC₅₀ 141 µM), LAMA84 (IC₅₀ 86 µM), Ba/F3 T315I (IC₅₀ 26 µM), Ba/F3 WT (IC₅₀ 22 µM) and KU812 (IC₅₀ 35 µM) proliferation, and induced apoptosis in these CML cell lines. Stachydrine significantly induced apoptosis, inhibited colony formation and self-renewal in BP-CML CD34⁺ cells. The combination index of stachydrine and TKI combination was <1. Compared to TKI alone, the combination of stachydrine and TKI significantly induced more apoptosis and decreased colony formation in BP-CML CD34⁺ cells. Stachydrine decreased phosphorylation levels of multiple receptor tyrosine kinases in CML cells.

DISCUSSION AND CONCLUSIONS

Our study is the first to demonstrate (1) the anticancer activity of stachydrine on primary patient cancer cells; (2) the inhibitory effects of stachydrine on cancer stem cells; (3) the synergism between stachydrine and other anticancer drugs.

A mitochondria-targeted nano-platform for pancreatic cancer therapy

Liposome is a conventional drug delivery system which has been widely used in the pharmacy field. However, its applications are greatly restricted in clinical practice by the disadvantages of cholesterol and nonselective distribution. Herein, a novel platform for anti-tumor drug delivery was developed by incorporating an amphiphilic stachydrine-octadecane conjugate (SS) as the mitochondria-targeting molecule onto the triptolide-liposome surfaces (SS-TP LPs). The polyethylene glycol (PEG) and the suitable particle size (about 133 nm) of liposomes facilitated their stabilities, the long half-life in blood and the escape from the rapid elimination. The SS-TP LPs were internalized and accumulated into the mitochondria of cancer cells in a time-dependent manner, followed by triggering permeabilization of the mitochondrial outer membrane by inhibiting Bcl-2, and then further caused greater cancer cell death via releasing cytochrome C and initiating a cascade of caspase 3 reactions. In the Pan02 tumor-bearing mice, the SS-TP LPs showed significant efficacy in inhibiting tumor growth and reducing tumor size but synchronously exhibited specific mitochondria-targeting and much lower subacute toxicity compared with the free TP and TP LPs. Our study suggests that SS-TP LPs can be a promising anticancer drug delivery system for mitochondria-targeted therapy in pancreatic cancer.

Maintenance of Epstein-Barr virus latency through interaction of LMP2A with CXCR4

Epstein-Barr virus (EBV) belongs to the subfamily Gammaherpesvirinae and was the first human tumor virus to be discovered. The global rate of EBV infection in adults exceeds 90%. EBV can participate in the regulation of multiple genes and signal pathways through its latency genes. Many studies have shown that CXCR4 is involved in the development of gastric cancer, but there have been few studies on the specific mechanisms involved in EBV-associated gastric cancer (EBVaGC). In this study, we explored the mechanism by which EBV-encoded products maintain latent EBV infection through interaction with CXCR4 and investigated the role of CXCR4 in EBV-positive cells. The results show that there is a positive feedback between the EBV-encoded products and CXCR4, and LMP2A can activate CXCR4 through the NF-κB pathway. In addition, CXCR4 can be fed back to LMP2A and EBNA1 through the ERK signaling pathway. At the same time, CXCR4 can promote the proliferation and migration of EBV-positive cells, reduce the expression of the immediate early protein BZLF1, the late protein EBV gp350, and the viral capsid antigen, and play an important role in maintaining the incubation period of EBV infection. These findings are applicable to the further targeted therapy of EBVaGC.

Stachydrine inhibits TGF-β1-induced epithelial-mesenchymal transition in hepatocellular carcinoma cells through the TGF-β/Smad and PI3K/Akt/mTOR signaling pathways

Stachydrine is a bioactive alkaloid that has been found to exert tumor-suppressive potential. However, the effect of stachydrine on hepatocellular carcinoma (HCC) has not been previously investigated. In the present study, we investigated the effect of transforming growth factor-β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) in HepG2 cells. Our results showed that stachydrine significantly suppressed TGF-β1-induced HepG2 cell migration and invasion in a dose-dependent manner. Stachydrine prevented TGF-β1-induced EMT in HepG2 cells, as proved by the increased expression level of E-cadherin and decreased expression levels of N-cadherin and vimentin. In addition, stachydrine attenuated TGF-β1-induced upregulation of TGF-β receptor I (TβRI) in both protein and mRNA levels. Further mechanism investigations proved that stachydrine prevented TGF-β1-induced activation of Smad2/3 and phosphoinositol-3-kinase (PI3K)/Akt/mTOR signaling pathways in HepG2 cells. In conclusion, these findings demonstrated that stachydrine prevented TGF-β1-induced EMT in HCC cells through Smad2/3 and PI3K/Akt/mTOR signaling pathways. Thus, stachydrine might be a potential therapeutic agent for the treatment of HCC.

Tumor microenvironment: a prospective target of natural alkaloids for cancer treatment

Malignant tumor has become one of the major diseases that seriously endangers human health. Numerous studies have demonstrated that tumor microenvironment (TME) is closely associated with patient prognosis. Tumor growth and progression are strongly dependent on its surrounding tumor microenvironment, because the optimal conditions originated from stromal elements are required for cancer cell proliferation, invasion, metastasis and drug resistance. The tumor microenvironment is an environment rich in immune/inflammatory cells and accompanied by a continuous, gradient of hypoxia and pH. Overcoming immunosuppressive environment and boosting anti-tumor immunity may be the key to the prevention and treatment of cancer. Most traditional Chinese medicine have been proved to have good anti-tumor activity, and they have the advantages of better therapeutic effect and few side effects in the treatment of malignant tumors. An increasing number of studies are giving evidence that alkaloids extracted from traditional Chinese medicine possess a significant anticancer efficiency via regulating a variety of tumor-related genes, pathways and other mechanisms. This paper reviews the anti-tumor effect of alkaloids targeting tumor microenvironment, and further reveals its anti-tumor mechanism through the effects of alkaloids on different components in tumor microenvironment.

Interaction network of immune-associated genes affecting the prognosis of patients with glioblastoma

Glioblastoma multiforme (GBM) is a common malignant tumor type of the nervous system. The purpose of the present study was to establish a regulatory network of immune-associated genes affecting the prognosis of patients with GBM. The GSE4290, GSE50161 and GSE2223 datasets from the Gene Expression Omnibus database were screened to identify common differentially expressed genes (co-DEGs). A functional enrichment analysis indicated that the co-DEGs were mainly enriched in cell communication, regulation of enzyme activity, immune response, nervous system, cytokine signaling in immune system and the AKT signaling pathway. The co-DEGs accumulated in immune response were then further investigated. For this, the intersection of those co-DEGs and currently known immune-regulatory genes was obtained and a differential expression analysis of these overlapping immune-associated genes was performed. A risk model was established using immune-regulatory genes that affect the prognosis of patients with GBM. The risk score was significantly associated with the prognosis of patients with GBM and had a significant independent predictive value. The risk model had high accuracy in predicting the prognosis of patients with GBM [area under the receiver operating characteristic curve (AUC)=0.764], which was higher than that of a previously reported model of prognosis-associated biomarkers (AUC=0.667). Furthermore, an interaction network was constructed by using immune-regulatory genes and transcription factors affecting the prognosis of patients with GBM and the University of California Santa Cruz database was used to perform a preliminary analysis of the transcription factors and immune genes of interest. The interaction network of immune-regulatory genes constructed in the present study enhances the current understanding of mechanisms associated with poor prognosis of patients with GBM. The risk score model established in the present study may be used to evaluate the prognosis of patients with GBM.

Stachydrine attenuates IL-1β-induced inflammatory response in osteoarthritis chondrocytes through the NF-κB signaling pathway

Osteoarthritis (OA) is a common degenerative joint disease that is closely associated with inflammation. Stachydrine (STA) is a bioactive alkaloid with anti-inflammatory activity. However, the role of STA in OA remains unknown. This study aimed to explore the effects of STA on OA chondrocytes in the presence of IL-1β. Primary human OA chondrocytes were pretreated with various concentrations of STA for 2 h and then stimulated with IL-1β for 24 h. Inflammatory mediators and cytokines including NO, PGE2, TNF-α and IL-6 in chondrocytes were detected to reflect inflammation status. Production of extracellular matrix (ECM) degrading enzymes including MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 in chondrocytes was measured using ELISA. The expression levels of iNOS, COX-2, p65, p-p65, p-IκBα, and IκBα were detected by Western blot analysis. Our results showed that STA significantly suppressed IL-1β-induced inflammation with decreased levels of inflammatory mediators and cytokines including NO, PGE2, iNOS, COX-2, TNF-α and IL-6. Treatment with STA suppressed the production of ECM degrading enzymes including MMP-3, MMP-13, ADAMTS-4, and ADAMTS-5 in IL-1β-induced chondrocytes. Furthermore, STA blocked the IL-1β-mediated potentiation of NF-κB pathway in chondrocytes. In conclusion, these findings demonstrated that STA protected chondrocytes from IL-1β-induced inflammation through the NF-κB signaling pathway.

Induction of peroxisome proliferator activated receptor γ (PPARγ) mediated gene expression and inhibition of induced nitric oxide production by Maerua subcordata (Gilg) DeWolf

BACKGROUND

The health benefits of botanicals is linked to their phytochemicals that often exert pleiotropic effects via targeting multiple molecular signaling pathways such as the peroxisome proliferator-activated receptors (PPARs) and the nuclear factor kappaB (NFκB). The PPARs are transcription factors that control metabolic homeostasis and inflammation while the NF-κB is a master regulator of inflammatory genes such as the inducible nitric-oxide synthase that result in nitric oxide (NO) overproduction.

METHODS

Extracts of Maerua subcordata (MS) and selected candidate constituents thereof, identified by liquid chromatography coupled to mass spectroscopy, were tested for their ability to induce PPARγ mediated gene expression in U2OS-PPARγ cells using luciferase reporter gene assay and also for their ability to inhibit lipopolysaccharide (LPS) induced NO production in RAW264.7 macrophages. While measuring the effect of test samples on PPARγ mediated gene expression, a counter assay that used U2OS-Cytotox cells was performed to monitor cytotoxicity or any non-specific changes in luciferase activity.

RESULTS

The results revealed that the fruit, root, and seed extracts were non-cytotoxic up to a concentration of 30 g dry weight per litre (gDW/L) and induced PPARγ mediated gene expression but the leaf extract showed some cytotoxicity and exhibited minimal induction. Instead, all extracts showed concentration (1-15 gDW/L) dependent inhibition of LPS induced NO production. The root extract showed weaker inhibition. Among the candidate constituents, agmatine, stachydrine, trigonelline, indole-3-carboxyaldehyde, plus ethyl-, isobutyl-, isopropyl, and methyl-isothiocyanates showed similar inhibition, and most showed increased inhibition with increasing concentration (1-100 μM) although to a lesser potency than the positive control, aminoguanidine.

CONCLUSION

The present study demonstrated for the first time the induction of PPARγ mediated gene expression by MS fruit, root, and seed extracts and the inhibition of LPS induced NO production by MS fruit, leaf, root, and seed extracts and some candidate constituents thereof.

A review of pharmacological and pharmacokinetic properties of stachydrine

Stachydrine is extracted from the leaves of Leonurus japonicus Houtt (or Motherwort, "Yi Mu Cao" in Traditional Chinese Medicine) and is the major bioactive ingredient. So far, stachydrine has demonstrated various bioactivities for the treatment of fibrosis, cardiovascular diseases, cancers, uterine diseases, brain injuries, and inflammation. The pharmacological and pharmacokinetic properties of stachydrine up to 2019 have been comprehensively searched and summarized. This review provides an updated summary of recent studies on the pharmacological activities of stachydrine. Many studies have demonstrated that stachydrine has strong anti-fibrotic properties (on various types of fibrosis) by inhibiting ECM deposition and decreasing inflammatory and oxidative stress through multiple molecular mechanisms (including TGF-β, ERS-mediated apoptosis, MMPs/TIMPs, NF-κB, and JAK/STAT). The cardioprotective and vasoprotective activities of stachydrine are related to its inhibition of β-MHC, excessive autophagy, SIRT1, eNOS uncoupling and TF, promotion of SERCA, and angiogenesis. In addition to its anticancer action, regulation of the uterus, neuroprotective effects, etc. the pharmacokinetic properties of stachydrine are also discussed.

Stachydrine prevents LPS-induced bone loss by inhibiting osteoclastogenesis via NF-κB and Akt signalling

Osteoclast overactivation‐induced imbalance in bone remodelling leads to pathological bone destruction, which is a characteristic of many osteolytic diseases such as rheumatoid arthritis, osteoporosis, periprosthetic osteolysis and periodontitis. Natural compounds that suppress osteoclast formation and function have therapeutic potential for treating these diseases. Stachydrine (STA) is a bioactive alkaloid isolated from Leonurus heterophyllus Sweet and possesses antioxidant, anti‐inflammatory, anticancer and cardioprotective properties. However, its effects on osteoclast formation and function have been rarely described. In the present study, we found that STA suppressed receptor activator of nuclear factor‐κB (NF‐κB) ligand (RANKL)‐induced osteoclast formation and bone resorption, and reduced osteoclast‐related gene expression in vitro. Mechanistically, STA inhibited RANKL‐induced activation of NF‐κB and Akt signalling, thus suppressing nuclear factor of activated T cells c1 induction and nuclear translocation. In addition, STA alleviated bone loss and reduced osteoclast number in a murine model of LPS‐induced inflammatory bone loss. STA also inhibited the activities of NF‐κB and NFATc1 in vivo. Together, these results suggest that STA effectively inhibits osteoclastogenesis both in vitro and in vivo and therefore is a potential option for treating osteoclast‐related diseases.