Ginsenoside Rg3 protects mouse leydig cells against triptolide by downregulation of miR-26a

Triptolide Causes Spermatogenic Disorders by Inducing Apoptosis in the Mitochondrial Pathway of Mouse Testicular Spermatocytes

Triptolide (TP) is a diterpenoid compound extracted from the traditional Chinese medicinal herb Tripterygium wilfordii. It has antitumor and anti-inflammatory effects and stimulates immunity. However, its serious side effects, especially reproductive toxicity, limit its clinical application. This study employed a testicular injury model established by intraperitoneally injecting TP (0.2 mg/kg) in C57BL/6J male mice (age = 7-8 weeks) for 14 days. The control and TP mice's testicular tissues were subjected to transcriptome sequencing to assess potential testicular damage mechanisms. Based on the transcriptome sequencing results and relevant literature reports, further experiments were performed. In addition, to alleviate triptolide-induced testicular damage, we treated the mice with N-acetyl-L-cysteine (NAC). The acquired data revealed that compared with the control mice, the TP-treated mice's testes indicated severe damage. Transcriptome sequencing identified differentially expressed genes that showed enrichment in cell differentiation, apoptotic process, cell cycle, glutathione (GSH) metabolism, and the p53 signaling pathway. Furthermore, TUNEL assays and Western blot analysis showed that in the TP mice's testicular tissues, the spermatocytes had mitochondrial pathway apoptosis as well as abnormal mitochondrial morphology and structure. Triptolide induces oxidative stress in testicular tissue by enhancing pro-oxidative systems and inhibiting antioxidant systems. NAC reduced testicular damage and apoptosis by alleviating TP-induced oxidative stress. This study also employed a GC2 cell line for in-vitro analyses, and the results were consistent with the in vivo experiments. This study provides evidence for alleviating TP's adverse effects on the male reproductive system for better clinical application.

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.

Triptolide induced spermatogenesis dysfunction via ferroptosis activation by promoting K63-linked GPX4 polyubiquitination in spermatocytes

Triptolide (TP) is a major bioactive compound derived from Tripterygium wilfordii Hook. F. (TwHF) known for its medicinal properties, but it also exhibits potential toxic effects. It has been demonstrated to induce severe male reproductive toxicity, yet the precise mechanism behind this remains unclear, which limits its broad clinical application. This study aimed to investigate the mechanisms underlying testicular damage and spermatogenesis dysfunction induced by TP in mice, using both mouse models and the spermatocyte-derived cell line GC-2spd. In the present study, it was found that TP displayed significant testicular microstructure damaged and spermatogenesis defects including lower concentration and abnormal morphology by promoting ROS formation, MDA production and restraining GSH level, glutathione peroxidase 4 (GPX4) expression in vivo. Furthermore, Ferrostatin-1 (FER-1), a ferroptosis inhibitor, was found to significantly reduce the accumulation of lipid peroxidation, alleviate testicular microstructural damage, and enhance spermatogenic function in mice. Besides, notably decreased cell viability, collapsed mitochondrial membrane potential, and elevated DNA damage were observed in vitro. The above-mentioned phenomenon could be reversed by pre-treatment of FER-1, indicating that ferroptosis participated in the TP-mediated spermatogenesis dysfunction. Mechanistically, TP could enhance GPX4 ubiquitin degradation via triggering K63-linked polyubiquitination of GPX4, thereby stimulating ferroptosis in spermatocytes. Functionally, GPX4 deletion intensified ferroptosis and exacerbated DNA damage in GC-2 cells, while GPX4 overexpression mitigated ferroptosis induced by TP. Overall, these findings for the first time indicated a vital role of ferroptosis in TP induced-testicular injury and spermatogenic dysfunction through promoting GPX4 K63-linked polyubiquitination, which hopefully offers a potential therapeutic avenue for TP-related male reproductive damage. In addition, this study also provides a theoretical foundation for the improved clinical application of TP or TwHF in the future.

Functions and targets of miRNAs in pharmacological and toxicological effects of major components of Tripterygium wilfordii Hook F

Tripterygium wilfordii Hook F (TwHF) has a long history of use as a traditional Chinese medicine and has been widely administered to treat various inflammatory and autoimmune diseases. MicroRNAs (miRNAs) are endogenous, short, non-coding RNAs that regulate gene expression post-transcriptionally. They participate in the efficacies and even toxicities of the components of TwHF, rendering miRNAs an appealing therapeutic strategy. This review summarizes the recent literature related to the roles and mechanisms of miRNAs in the pharmacological and toxicological effects of main components of TwHF, focusing on two active compounds, triptolide (TP) and celastrol (CEL). Additionally, the prospects for the "You Gu Wu Yun" theory regarding TwHF nephrotoxicity are presented.

Detoxification strategies of triptolide based on drug combinations and targeted delivery methods

Tripterygium wilfordii Hook f. has a long history of use in Chinese medicine. Triptolide (TP), as its main pharmacological component, has been widely explored in various diseases, including systemic lupus erythematosus, rheumatoid arthritis and cancer. However, due to its poor water solubility, limited therapeutic range and multi-organ toxicity, TP's clinical application has been greatly hampered. To improve its clinical potential, many attenuated drug combinations have been developed based on its toxicity mechanism and targeted delivery systems aimed at its water-solubility and structure. This review, conducted a systematic review of TP detoxification strategies including drug combination detoxification strategies from metabolic and toxic mechanisms, as well as drug delivery detoxification strategies from the prodrug strategy and nanotechnology. Many detoxification strategies have demonstrated promising potential in vitro and in vivo due to previous extensive studies on TP. Therefore, summarizing and discussing TP detoxification strategies for clinical problems can serve as a reference for developing novel TP detoxification strategies, and provide opportunities for future clinical applications.

MicroRNAs as crucial mediators in the pharmacological activities of triptolide (Review)

Triptolide is the main bioactive constituent isolated from the Chinese herb Tripterygium wilfordii Hook F., which possesses a variety of pharmacological properties. MicroRNAs (miRNAs/miRs) are short non-coding RNAs that regulate gene expression post-transcriptionally. miRNAs are implicated in several intracellular processes, whereby their dysregulation contributes to pathogenesis of various diseases. Thus, miRNAs have great potential as biomarkers and therapeutic targets for diseases, and are implicated in drug treatment. Previous studies have reported that specific miRNAs are targeted, and their expression levels can be altered following exposure to triptolide. Thus, miRNAs are emerging as crucial mediators in the pharmacological activities of triptolide. The present review summarizes current literature on miRNAs as target molecules in the pharmacological activities of triptolide, including antitumor, anti-inflammatory, immunosuppressive, renal protective, cardioprotective, antiangiogenesis activities and multiorgan toxicity effects. In addition, the diverse signaling pathways involved are discussed to provide a comprehensive understanding of the underlying molecular mechanisms of triptolide in the regulation of target miRNAs.

Triptolide Induces Leydig Cell Apoptosis by Disrupting Mitochondrial Dynamics in Rats

Triptolide is widely used in the clinical treatment of various diseases. Side effects, including reproductive toxicity to male patients, limit its application. However, no detailed mechanisms or potential intervention targets have been reported. In this study, we show that triptolide activated the mitochondrial apoptosis pathway in rat testicular Leydig cells and induced apoptosis both in vivo and in vitro, which may cause hypoleydigism and impair spermatogenesis. Mechanistically, triptolide-induced dynamin-related protein 1 (Drp1) overexpression, which interfered with mitochondrial dynamic stability to activate the mitochondrial apoptosis pathway. Mdivi-1, a selective Drp1 inhibitor, partially reversed the mitochondrial dynamic disturbance and rat testicular Leydig cell apoptosis induced by triptolide. Inhibiting Drp1 over-activation may be a new strategy for mitigating the reproductive toxicity of triptolide.

Downregulation of miR-200a Protects Mouse Leydig Cells Against Triptolide by Triggering Autophagy

Background

MicroRNAs play important roles in testicular development and spermatogenesis. Previous research has indicated that the level of miR-200a was significantly upregulated in patients with different spermatogenic impairments. However, the mechanism by which miR-200a regulated spermatogenic impairments remains unclear.

Methods

Leydig cells were treated with triptolide (TP) to mimic spermatogenic impairments. CCK-8 and flow cytometry were used to detect the proliferation and apoptosis in Leydig cells, respectively. In addition, Western blot assay was used to examine ATG7, ATG5, p62 protein levels in MLTC-1 cells.

Results

TP dose-dependently upregulated the expression of miR-200a in MLTC-1 cells. In addition, TP inhibited the proliferation of MLTC-1 cells via inducing apoptosis and oxidative stress; however, these phenomena were notably reversed by miR-200a antagomir. Furthermore, luciferase reporter assay identified that ATG7 was the direct binding target of miR-200a. TP treatment markedly inhibited the activation of autophagy in MLTC-1 cells via inhibition of ATG7. Conversely, downregulation of miR-200a significantly induced autophagy in TP-treated MLTC-1 cells by activation of ATG7. Meanwhile, the cell protective effects of miR-200a against TP were reversed by autophagy inhibitor 3MA, indicating that autophagy plays an important role.

Conclusion

These results indicated that downregulation of miR-200a could protect MLTC-1 cells against TP by inducing autophagy. Therefore, miR-200a might serve as a new therapeutic target for the treatment of male hypogonadism.

MicroRNAs mediate the anti-tumor and protective effects of ginsenosides

MicroRNAs (miRs(, as short non-coding RNAs, regulate important biological processes and mainly are associated with regulation of gene expression. The miRs are beneficial targets for diagnosis of various disorders, particularly cancer, since their expression profile undergoes alterations in pathological conditions. The numerous drugs have been designed with the capability of targeting miRs for treating pathological conditions. On the other hand, the application of naturally occurring compounds has been increased due to their minimal side effects and valuable biological and therapeutic activities. Ginsenosides are able to act as anti-tumor agents via either increasing or decreasing the expression level of miRs. Ginsenosides affect the expression profile of miRNAs to induce their protective impacts. Angiogenesis as a key factor in the progression of cancer can be suppressed by ginsenosides which is mediated by miR regulation. The aim of this review is to shed some light on the protective and anti-tumor activities of ginsenosides mediated by miRNAs.