Toxicity of a novel anti-tumor agent 20(S)-ginsenoside Rg3: a 26-week intramuscular repeated administration study in rats

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 Rg3: A Review of its Anticancer Mechanisms and Potential Therapeutic Applications

BACKGROUND

Traditional Chinese Medicine (TCM) has a long history of treating various diseases and is increasingly being recognized as a complementary therapy for cancer. A promising natural compound extracted from the Chinese herb ginseng is ginsenoside Rg3, which has demonstrated significant anticancer effects. It has been tested in a variety of cancers and tumors and has proven to be effective in suppressing cancer.

OBJECTIVES

This work covers various aspects of the role of ginsenoside Rg3 in cancer treatment, including its biological functions, key pathways, epigenetics, and potential for combination therapies, all of which have been extensively researched and elucidated. The study aims to provide a reference for future research on ginsenoside Rg3 as an anticancer agent and a support for the potential application of ginsenoside Rg3 in cancer treatment.

Ginsenoside Rg3 liposomes regulate tumor microenvironment for the treatment of triple negative breast cancer

OBJECTIVE

To improve the solubility and targeting of Ginsenoside Rg3 (G-Rg3), in the current study, we constructed a novel targeting functional material folic acid -poly(2-ethyl-2-oxazoline)-cholesteryl methyl carbonate (FA-PEOz-CHMC, FPC) modified G-Rg3 liposomes (FPC-Rg3-L).

METHODS

FPC was synthesized by using folic acid (FA) as a targeted head coupling with acid-activated poly(2-ethyl-2-oxazoline)-cholesteryl methyl carbonate. The inhibitory effects of the G-Rg3 preparations on mouse breast cancer cells (4T1) were investigated by CCK-8 assay. Paraffin sections of female BALB/c mice viscera were taken for hematoxylin-eosin (H&E) staining after continuous tail vein injection of G-Rg3 preparations. BALB/c mice bearing triple-negative breast cancer (TNBC) were used as animal models to investigate the inhibition of G-Rg3 preparations on tumor growth and improving quality of life. Transforming growth factor-β1 (TGF-β1) and α-smooth muscular actin (α-SMA) were used to investigate the expression of two fibrosis factors in tumor tissues by western blotting.

RESULTS

Compared with G-Rg3 solution (Rg3-S) and Rg3-L, FPC-Rg3-L had a significant inhibitory effect on 4T1 cells (p < .01), and the half maximal inhibitory concentration (IC₅₀) of FPC-Rg3-L was significantly lower (p < .01). The H&E results showed that the injection of FPC-Rg3-L and Rg3-S did not cause damage to the organs of mice. Compared with the control group, tumor growth was significantly inhibited in mice treated with FPC-Rg3-L and G-Rg3 solutions (p < .01).

CONCLUSIONS

This study presents a new and safe treatment for TNBC, reduces the toxic and side effects of the drug, and provides a reference for the efficient use of Chinese herbal medicine components.

Multiple targeted self-emulsifying compound RGO reveals obvious anti-tumor potential in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly vascularized, inflammatory, and abnormally proliferating tumor. Monotherapy is often unable to effectively and comprehensively inhibit the progress of HCC. In present study, we selected ginsenoside Rg3, ganoderma lucidum polysaccharide (GLP), and oridonin as the combined therapy. These three plant monomers play important roles in anti-angiogenesis, immunological activation, and apoptosis promotion, respectively. However, the low solubility and poor bioavailability seriously hinder their clinical application. To resolve these problems, we constructed a new drug, Rg3, GLP, and oridonin self-microemulsifying drug delivery system (RGO-SMEDDS). We found that this drug effectively inhibits the progression of HCC by simultaneously targeting multiple signaling pathways. RGO-SMEDDS restored immune function by suppressing the production of immunosuppressive cytokine and M2-polarized macrophages, reduced angiogenesis by downregulation of vascular endothelial growth factor and its receptor, and retarded proliferation by inhibiting the epidermal growth factor receptor EGFR/AKT/epidermal growth factor receptor/protein kinase B/glycogen synthase kinase-3 (GSK3) signaling pathway. In addition, RGO-SMEDDS showed considerable safety in acute toxicity tests. Results from this study show that RGO-SMEDDS is a promising therapy for the treatment of HCC.

A review of anti-tumour effects of ginsenoside in gastrointestinal cancer

OBJECTIVES

Gastrointestinal cancer, one of the major causes of cancer-related deaths in the world, refers to malignant conditions of the gastrointestinal (GI) tract and other organs. Although conventional therapy has been successful to some extent in cancer treatment, drug resistance and cancer recurrence still limit the therapeutic efficacy. There is increasing evidence indicating that ginsenoside, as a kind of high nutritional value and widely used traditional Chinese medicine, could contribute to the promotion of treatment in GI cancer, which deserves further investigation.

KEY FINDINGS

Based on previous studies, the possible mechanisms mainly include regulation of autophagy, apoptosis, proliferation, migration and angiogenesis. However, no studies recently have conducted a more in-depth review of the anti-cancer effects of ginsenoside in GI cancer.

SUMMARY

Therefore, this review will summarise and analyse the latest developments in the anti-tumour effects of ginsenosides in GI cancer, thus may promote further research of the anti-tumour efficacy of ginsenoside.

Ginsenoside Rg3, a component of ginseng, induces pro-thrombotic activity of erythrocytes via hemolysis-associated phosphatidylserine exposure

Ginseng and its active gradient, ginsenoside Rg3 (Rg3), are widely used for a variety of health benefits, but concerns over their misuses are increasing. Previously, it has been reported that Rg3 can cause hemolysis, but its health outcome remains unknown. Here, we demonstrated that Rg3 could promote the procoagulant activity of erythrocytes through the process of hemolysis, ultimately leading to increased thrombosis. In freshly isolated human erythrocytes, Rg3 caused pore formation and fragmentation of the erythrocyte membrane. Confocal microscopy observation and flow cytometric analysis revealed that remnant erythrocyte fragments after the exposure to Rg3 expressed phosphatidylserine (PS), which can promote blood coagulation through providing assembly sites for coagulation complexes. Rat in vivo experiments further confirmed that intravenous administration of Rg3 produced PS-bearing erythrocyte debris and increased thrombosis. Collectively, we demonstrated that Rg3 could induce the procoagulant activity of erythrocytes by generating PS-bearing erythrocyte debris through hemolysis, which might provoke thrombosis.

Analytical methods and biological activities of Panax notoginseng saponins: Recent trends

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng (Burk.) F. H. Chen, also called Sanqi, is a widely used traditional Chinese medicine, which has long history used as herbal medicines. It is currently an important medicinal material in China, holding the first place in the sale volume of the whole patent medicines market in China, and the market size of the single species has exceeded 10 billion yuan. In addition, P. notoginseng is an important constituent part of many famous Chinese patent medicines, such as Compound Danshen Dripping Pills and Yunnan Baiyao. P. notoginseng saponins (PNSs), which are the major active components of P. notoginseng, are a kind of chemical mixture containing different dammarane-type saponins. Many studies show that PNSs have been extensively used in medical research or applications, such as atherosclerosis, diabetes, acute lung injury, cancer, and cardiovascular diseases. In addition, various PNS preparations, such as injections and capsules, have been made commercially available and are widely applied in clinical practice.

AIM OF THE REVIEW

Since the safety and efficacy of compounds are related to their qualitative and quantitative analyses, this review briefly summarizes the analytic approaches for PNSs and their biological effects developed in the last decade.

METHODOLOGY

This review conducted a systematic search in electronic databases, such as Pubmed, Google Scholar, SciFinder, ISI Web of Science, and CNKI, since 2009. The information provided in this review is based on peer-reviewed papers and patents in either English or Chinese.

RESULTS

At present, the chromatographic technique remains the most extensively used approach for the identification or quantitation of PNSs, coupled with different detectors, among which the difference mainly lies in their sensitivity and specificity for analyzing various compounds. It is well-known that PNSs have traditionally strong activity on cardiovascular diseases, such as atherosclerosis, intracerebral hemorrhage, or brain injury. The recent studies showed that PNSs also responded to osteoporosis, cancers, diabetes, and drug toxicity. However, some other studies also showed that some PNSs injections and special PNS components might lead to some biological toxicity under certain dosages.

CONCLUSION

This review may be used as a basis for further research in the field of quantitative and qualitative analyses, and is expected to provide updated and valuable insights into the potential medicinal applications of PNSs.

20(S)-ginsenoside-Rg3 reverses temozolomide resistance and restrains epithelial-mesenchymal transition progression in glioblastoma

Glioblastoma multiforme (GBM) is one of the most malignant human intracranial tumors. Temozolomide (TMZ) is the primary alkylating agent for GBM patients. However, many GBM patients are resistant to TMZ. Therefore, patients with GBM urgently need more effective therapeutic options. 20(S)‐ginsenoside‐Rg3 (20(S)‐Rg3) is a natural chemical with anti‐tumor effects, but at present there is little understanding of its functional mechanism. Several research reports have demonstrated that O⁶‐methylguanine DNA‐methyltransferase (MGMT) repairs damaged DNA and contributes to TMZ resistance in gliomas. In addition, recent studies have shown that MGMT gene expression could be regulated by the Wnt/β‐catenin pathway. However, whether 20(S)‐Rg3 inhibits MGMT expression and augments chemosensitivity to Temozolomide (TMZ) in glioma cells remains unclear. In this study, we explored the modulating effects of 20(S)‐Rg3 on MGMT. We used glioma cell lines, primary cell strain (including T98G, U118 and GBM‐XX; all of them are MGMT‐positive glioma cell lines) and xenograft glioma models to examine whether 20(S)‐Rg3 increased the sensitivity to TMZ and to reveal the underlying mechanisms. We found that the MGMT expression was effectively downregulated by 20(S)‐Rg3 via the Wnt/β‐catenin pathway in glioma cell lines, and TMZ resistance was significantly reversed by 20(S)‐Rg3. Meanwhile, 20(S)‐Rg3 shows no obvious cytotoxicity at its effective dose and is well tolerated in vivo. In addition, we found that 20(S)‐Rg3 significantly restrains the epithelial‐mesenchymal transition (EMT) progression of glioma cells. Taken together, these results indicate that 20(S)‐Rg3 may be a novel agent to use in treatment of GBM, especially in TMZ‐resistant GBM with high MGMT expression.

Acute and repeated dose 26-week oral toxicity study of 20(S)-ginsenoside Rg3 in Kunming mice and Sprague-Dawley rats

Background

20(S)-ginsenoside-Rg3 (C₄₂H₇₂O₁₃), a natural triterpenoid saponin, is extracted from red ginseng. The increasing use of 20(S)-ginsenoside Rg3 has raised product safety concerns.

Methods

In acute toxicity, 20(S)-ginsenoside Rg3 was singly and orally administrated to Kunming mice and Sprague–Dawley (SD) rats at the maximum doses of 1600 mg/kg and 800 mg/kg, respectively. In the 26-week toxicity study, we used repeated oral administration of 20(S)-ginsenoside Rg3 in SD rats over 26 weeks at doses of 0, 20, 60, or 180 mg/kg. Moreover, a 4-week recovery period was scheduled to observe the persistence, delayed occurrence, and reversibility of toxic effects.

Results

The result of acute toxicity shows that oral administration of 20(S)-ginsenoside Rg3 to mice and rats did not induce mortality or toxicity up to 1600 and 800 mg/kg, respectively. During a 26-week administration period and a 4-week withdrawal period (recovery period), there were no significant differences in clinical signs, body weight, food consumption, urinalysis parameters, biochemical and hematological values, or histopathological findings.

Conclusion

The mean oral lethal dose (LD₅₀) of 20(S)-ginsenoside Rg3, in acute toxicity, is above 1600 mg/kg and 800 mg/kg in mice and rats, respectively. In a repeated-dose 26-week oral toxicity study, the no-observed-adverse-effect level for female and male SD rats was 180 mg/kg.

Ginsenoside Rg3 Inhibition of Thyroid Cancer Metastasis Is Associated with Alternation of Actin Skeleton

Ginsenoside Rg3, a bioactive constituent from Panax ginseng, is a worldwide well-known traditional Chinese medicine used as a tonic. It also has good antitumor activity by inhibiting tumors metastasis. Tumor metastasis is a high risk in thyroid cancer. However, the effect and molecular mechanism underlying the antimetastatic activity of Rg3 in thyroid cancer have not been reported. In our study, we found that Rg3 inhibited the growth of thyroid cancer in vitro and in vivo and significantly inhibited metastasis of thyroid cancer. Rg3 apparently inhibited the migration and invasion in four papillary thyroid cancer (PTC) cells (TPC-1, BCPAP, C643, and Ocut-2c cells) and pulmonary metastasis in lung metastasis model of C643 cells in nude mice. We further found that a possible mechanism of Rg3 inhibiting thyroid cancer cells metastasis was associated with inhibiting cells actin skeleton function. Rg3 inhibited lamellipodia formation and induced microspike formation by inhibiting Rho GTPase in thyroid cancer cells. Rg3 decreased the levels of Rac-1 and Cdc42 proteins. In addition, Rg3 decreased the expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 proteins in four thyroid cancer cells. The results that Rg3 remarkably inhibited the expression of vascular endothelial growth factor-C (VEGF-C) protein in PTC cells and VEGF-A protein in anaplastic thyroid cancer (ATC) cells and decreased the staining of CD31 in PTC and ATC tumors hinted that Rg3 might inhibit the lymph node metastasis in PTC and angiogenesis in ATC. These studies suggested that Rg3 might be a useful agent for the treatment of metastatic thyroid cancers.

Ginsenoside Rg3 inhibits keloid fibroblast proliferation, angiogenesis and collagen synthesis in vitro via the TGF‑β/Smad and ERK signaling pathways

A wide range of therapeutic options exists for the treatment of keloids, all of which have their own strengths; however, a high risk of side-effects and frequent recurrence remains. Therefore, the present study aimed to identify improved therapeutic approaches or drugs for the treatment of keloids. Ginsenoside Rg3 (Rg3) has been reported to exert numerous antitumor effects, thus indicating that Rg3 may be a potential therapeutic agent that targets keloids. The present study determined the effects of Rg3 on human keloid fibroblasts (KFs) in vitro, and further explored the associated molecular and cellular mechanisms. Keloid scar specimens were obtained from patients, aged between 22 and 35 years, without systemic diseases and primary cells were isolated from keloid tissues. In each assay, KFs were divided into three groups and were cultured in medium with or without various concentrations of Rg3 (50 or 100 μg/ml). Cell viability assay, flow cytometry, quantitative polymerase chain reaction, cell migration assay, immunofluorescence staining, western blot analysis, Transwell cell invasion assay and immunohistochemical analysis were used to analyze the KFs and keloid explant cultures. The results of the present study demonstrated that Rg3 was able to exert an inhibitory effect on the transforming growth factor-β/Smad and extracellular signal-regulated kinase signaling pathways in KFs. The proliferation, migration, invasion, angiogenesis and collagen synthesis of KFs were markedly suppressed following treatment with Rg3. Furthermore, the results of an ex vivo assay indicated that Rg3 inhibited angiogenesis and reduced collagen accumulation in keloids. Significant statistical differences existed between the control and Rg3-treated groups (P<0.05). All of these experimental results suggested that Rg3 may serve as a reliable drug for the treatment of patients with keloids.

Anticancer effects of ginsenoside Rg3 (Review)

Cancer is a life-threatening disease with an alarmingly increased annual mortality rate globally. Although various therapies are employed for cancer, the final effect is not satisfactory. Chemotherapy is currently the most commonly used treatment option. However, the unsatisfactory efficacy, severe side-effects and drug resistance hinder the therapeutic efficacy of chemotherapeutic drugs. There is increasing evidence indicating that ginsenoside Rg3, a naturally occurring phytochemical, plays an important role in the prevention and treatment of cancer. The suggested mechanisms mainly include the induction of apoptosis, and the inhibition of proliferation, metastasis and angiogenesis, as well as the promotion of immunity. In addition, ginsenoside Rg3 can be used as an adjuvant to conventional cancer therapies, improving the efficacy and/or reducing adverse effects via synergistic activities. Ginsenoside Rg3 may be a widely applied natural medicine against cancer. To date however, there is no systematic summary available of the anticancer effects of ginsenoside Rg3. Therefore, in this review, all available literature over the past 10 years was reviewed and discussed in order to facilitate further research of ginsenoside Rg3.

20(S)-ginsenoside Rg3 promotes senescence and apoptosis in gallbladder cancer cells via the p53 pathway

Gallbladder cancer (GBC), the most frequent malignancy of the biliary tract, is associated with high mortality and extremely poor prognosis. 20(S)-ginsenoside Rg3 (20(S)-Rg3) is a steroidal saponin with high pharmacological activity. However, the anticancer effect of 20(S)-Rg3 in human GBC has not yet been determined. In this study, we primarily found that 20(S)-Rg3 exposure suppressed the survival of both NOZ and GBC-SD cell lines in a concentration-dependent manner. Moreover, induction of cellular senescence and G₀/G₁ arrest by 20(S)-Rg3 were accompanied by a large accumulation of p53 and p21 as a result of murine double minute 2 (MDM2) inhibition. 20(S)-Rg3 also caused a remarkable increase in apoptosis via the activation of the mitochondrial-mediated intrinsic caspase pathway. Furthermore, intraperitoneal injection of 20(S)-Rg3 (20 or 40 mg/kg) for 3 weeks markedly inhibited the growth of xenografts in nude mice. Our results demonstrated that 20(S)-Rg3 potently inhibited growth and survival of GBC cells both in vitro and in vivo. 20(S)-Rg3 attenuated GBC growth probably via activation of the p53 pathway, and subsequent induction of cellular senescence and mitochondrial-dependent apoptosis. Therefore, 20(S)-Rg3 may be a potential chemotherapeutic agent for GBC therapy.

20(S)-Ginsenoside Rg3 is a novel inhibitor of autophagy and sensitizes hepatocellular carcinoma to doxorubicin

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. High mortality from HCC is mainly due to widespread prevalence and the lack of effective treatment, since systemic chemotherapy is ineffective, while the targeted agent Sorafenib extends median survival only briefly. The steroidal saponin 20(S)-ginsenoside Rg₃ from Panax ginseng C.A. Meyer is proposed to chemosensitize to various therapeutic drugs through an unknown mechanism. Since autophagy often serves as cell survival mechanism in cancer cells exposed to chemotherapeutic agents, we examined the ability of Rg₃ to inhibit autophagy and chemosensitize HCC cell lines to doxorubicin in vitro. We show that Rg₃ inhibits late stage autophagy, possibly through changes in gene expression. Doxorubicin-induced autophagy plays a protective role in HCC cells, and therefore Rg₃ treatment synergizes with doxorubicin to kill HCC cell lines, but the combination is relatively nontoxic in normal liver cells. In addition, Rg₃ was well-tolerated in mice and synergized with doxorubicin to inhibit tumor growth in HCC xenografts in vivo. Since novel in vivo inhibitors of autophagy are desirable for clinical use, we propose that Rg3 is such a compound, and that combination therapy with classical chemotherapeutic drugs may represent an effective therapeutic strategy for HCC treatment.

In vivo early intervention and the therapeutic effects of 20(s)-ginsenoside rg3 on hypertrophic scar formation

BACKGROUND

Intra-lesional injections of corticosteroids, interferon, and chemotherapeutic drugs are currently the most popular treatments of hypertrophic scar formation. However, these drugs can only be used after HS is formed, and not during the inflammatory phase of wound healing, which regulates the HS forming process.

OBJECTIVE

To investigate a new, effective, combining therapeutic and safe drug for early intervention and treatment for hypertrophic scars.

METHODS

Cell viability assay and flow cytometric analysis were studied in vitro. Animal studies were done to investigate the combining therapeutic effects of 20(S)-ginsenoside Rg3 (Rg3) on the inflammatory phase of wound healing and HS formation.

RESULTS

In vitro studies showed that Rg3 can inhibit HS fibroblasts proliferation and induce HSF apoptosis in a concentration-dependent manner. In vivo studies demonstrated that Rg3 can limit the exaggerated inflammation, and do not delay the wound healing process, which indicates that Rg3 could be used as an early intervention to reduce HS formation. Topical injection of 4 mg/mL Rg3 can reduce HS formation by 34%. Histological and molecular studies revealed that Rg3 injection inhibits fibroblasts proliferation thus reduced the accumulation of collagen fibers, and down-regulates VEGF expression in the HS tissue.

CONCLUSION

Rg3 can be employed as an early intervention and a combining therapeutic drug to reduce inflammation and HS formation as well.

13-week subchronic toxicity study of a novel ginsenoside composition from ginseng leaves in rats

UG0712 is a new ginsenoside extract processed from ginseng leaves. A subchronic toxicity study of UG0712 was conducted in male and female SD rats. Rats were treated with UG0712 at doses of 100, 400 and 1,600 mg/kg/day for 13 weeks, and observed followed by 4-week recovery period at a highest dose. No-treatment-related effects were observed regarding the mortality, ophthalmic examination, urinalysis and histopathology. Although the changes in clinical sign, body weight, organ weight, hematology, and serum biochemistry were observed, they were temporal and pharmacological effects. Based on the present experiment conditions, the no observed adverse effect level was considered to be more than 1,600 mg/kg/day in both sexes of rats.