20(S)-25-methoxyl-dammarane-3beta, 12beta, 20-triol, a novel natural product for prostate cancer therapy: activity in vitro and in vivo and mechanisms of action

Recent advances in dietary androgen receptor inhibitors

As a nuclear transcription factor, the androgen receptor (AR) plays a crucial role not only in normal male sexual differentiation and growth of the prostate, but also in benign prostatic hyperplasia, prostatitis, and prostate cancer. Multiple population-based epidemiological studies demonstrated that prostate cancer risk was inversely associated with increased dietary intakes of green tea, soy products, tomato, and so forth. Therefore, this review aimed to summarize the structure and function of AR, and further illustrate the structural basis for antagonistic mechanisms of the currently clinically available antiandrogens. Due to the limitations of these antiandrogens, a series of natural AR inhibitors have been identified from edible plants such as fruits and vegetables, as well as folk medicines, health foods, and nutritional supplements. Hence, this review mainly focused on recent experimental, epidemiological, and clinical studies about natural AR inhibitors, particularly the association between dietary intake of natural antiandrogens and reduced risk of prostatic diseases. Since natural products offer multiple advantages over synthetic antiandrogens, this review may provide a comprehensive and updated overview of dietary-derived AR inhibitors, as well as their potential for the nutritional intervention against prostatic disorders.

Study of novel ginsenoside metabolites targeting HSP70 as anti-prostate cancer drugs

Ginsenoside 20 (R)-25-methoxy-dammarane-3 β, twelve β, 20 triol (AD-1) is a promising new drug for the treatment of prostate cancer, but its bioavailability is low. This study investigated the effects of the main metabolites PD and M6 of AD-1 on prostate cancer cell PC3. The in vitro experimental results showed that the IC50 values of PC3 cells treated with PD and M6 were 65.61 and 11.72, respectively. Both PD and M6 inhibited the migration of PC3 cells, and the cell cycle was blocked in the G1 phase. The apoptosis rates of cells following M6 treatment at concentrations of 7.5, 15, and 30 μM were 13.4 %, 17.5 %, and 41.4 %, respectively, which stimulated the expression of apoptosis protein and significantly increased intracellular ROS levels. In xenograft models, PD and M6 have been reported to significantly inhibit tumor growth. We used a genome-wide mRNA expression profile to study the effects of PD and M6 on gene expression in PC3 cancer cells. PD and M6 induced downregulation of HSP70 subtypes HSPA1A and HSPA1B. RT-PCR confirmed that the significant down-regulation of HSP70 subtype expressions was consistent with the results of Transcriptome analysis. Moreover, M6 significantly downregulated the expression of AR, which was further proved by Western blot analysis. In summary, our research findings provide a scientific basis for interpreting the significant activity of AD-1 in prostate cancer, and for the research and development of PD and M6 as novel HSP70 inhibitors.

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.

Pharmacokinetics and pharmacodynamics of Rh2 and aPPD ginsenosides in prostate cancer: a drug interaction perspective

Ginsenoside Rh2 and its aglycon (aPPD) are one of the major metabolites from Panax ginseng. Preclinical studies suggest that Rh2 and aPPD have antitumor effects in prostate cancer (PCa). Our aims in this review are (1) to describe the pharmacokinetic (PK) properties of Rh2 and aPPD ginsenosides; 2) to provide an overview of the preclinical findings on the use of Rh2 and aPPD in the treatment of PCa; and (3) to highlight the mechanisms of its PK and pharmacodynamic (PD) drug interactions. Increasing evidence points to the potential efficacy of Rh2 or aPPD for PCa treatment. Based on the laboratory studies, Rh2 or aPPD combinations revealed an additive or synergistic interaction or enhanced sensitivity of anticancer drugs toward PCa. This review reveals that enhanced anticancer activities were demonstrated in preclinical studies through interactions of Rh2 and/or aPPD with the proteins related to PK (e.g., cytochrome P450 enzymes, transporters) or PD of the other anticancer drugs or PCa signaling pathways. In conclusion, combining Rh2 or aPPD with anti-prostate cancer drugs leads to PK or PD interactions which could facilitate either therapeutically beneficial or toxic effects.

Herb-drug interactions between Panax notoginseng or its biologically active compounds and therapeutic drugs: A comprehensive pharmacodynamic and pharmacokinetic review

ETHNOPHARMACOLOGICAL RELEVANCE

Herbs, along with the use of herb-drug interactions (HDIs) to combat diseases, are increasing in popularity worldwide. HDIs have two effects: favorable interactions that tend to improve therapeutic outcomes and/or minimize the toxic effects of drugs, and unfavorable interactions aggravating the condition of patients. Panax notoginseng (Burk.) F.H. Chen is a medicinal plant that has long been commonly used in traditional Chinese medicine to reduce swelling, relieve pain, clear blood stasis, and stop bleeding. Numerous studies have demonstrated the existence of intricate pharmacodynamic (PD) and pharmacokinetic (PK) interactions between P. notoginseng and conventional drugs. However, these HDIs have not been systematically summarized.

AIM OF THE REVIEW

To collect the available literature on the combined applications of P. notoginseng and drugs published from 2005 to 2022 and summarize the molecular mechanisms of interactions to circumvent the potential risks of combination therapy.

MATERIALS AND METHODS

This work was conducted by searching PubMed, Scopus, Web of Science, and CNKI databases. The search terms included "notoginseng", "Sanqi", "drug interaction," "synergy/synergistic", "combination/combine", "enzyme", "CYP", and "transporter".

RESULTS

P. notoginseng and its bioactive ingredients interact synergistically with numerous drugs, including anticancer, antiplatelet, and antimicrobial agents, to surmount drug resistance and side effects. This review elaborates on the molecular mechanisms of the PD processed involved. P. notoginseng shapes the PK processes of the absorption, distribution, metabolism, and excretion of other drugs by regulating metabolic enzymes and transporters, mainly cytochrome P450 enzymes and P-glycoprotein. This effect is a red flag for drugs with a narrow therapeutic window. Notably, amphipathic saponins in P. notoginseng act as auxiliary materials in drug delivery systems to enhance drug solubility and absorption and represent a new entry point for studying interactions.

CONCLUSION

This article provides a comprehensive overview of HDIs by analyzing the results of the in vivo and in vitro studies on P. notoginseng and its bioactive components. The knowledge presented here offers a scientific guideline for investigating the clinical importance of combination therapies. Physicians and patients need information on possible interactions between P. notoginseng and other drugs, and this review can help them make scientific predictions regarding the consequences of combination treatments.

Immunomodulatory, Anti-Inflammatory, and Anti-Cancer Properties of Ginseng: A Pharmacological Update

Ginseng, a medicinal plant of the genus Panax, boasts a rich historical record of usage that dates back to the Paleolithic period. This botanical is extensively acknowledged and consumed in Eastern countries for its therapeutic properties, and, in Western countries, it is becoming increasingly popular as a remedy for fatigue and asthenia. This review provides an update on current research pertaining to ginseng and its isolated compounds, namely, ginsenosides and polysaccharides. The primary focus is on three crucial pharmacological activities, namely, immunomodulation, anti-inflammatory, and anti-cancer effects. The review encompasses studies on both isolated compounds and various ginseng extracts obtained from the root, leaves, and berries.

In Vivo Metabolites of Panaxadiol Inhibit HepG-2 Cell Proliferation by Inducing G1 Arrest and ROS-Mediated Apoptosis

In this study, 10 metabolites were obtained by collecting and extracting fecal samples after oral administration of panaxadiol (PD). Of these 10 metabolites, M7 (3β,21β,22α-hydroxy-24-norolean-12-ene), M8 (21β,22α-hydroxy-24-norolean-12-ene-3-one), M9 (3β,30α-hydroxy-24-norolean-22,30-epoxy-12-ene), and M10 (3β,21β-hydroxy-24-norolean-12-ene) were new compounds. MTT screening of the isolated compounds revealed that the inhibitions of cancer cells by M2, M4, M7, M8, and M10 were significantly stronger than that by the mother drug M0, with the activity of M2 being the most significant. Further, we investigated the anticancer mechanism of M2. The results showed that M2 significantly increased the level of ROS in cells; regulated the expressions of Bax, Bcl-2, and Cyt-C through the mitochondrial pathway; triggered the caspase cascade; and induced apoptosis. M2 could also induce G1 phase arrest and significantly regulate cell cycle-related proteins. In conclusion, the experimental results provide data for further study on the metabolic mechanism of PD in vivo and the potential of developing new anti-cancer drugs.

A review for discovering bioactive minor saponins and biotransformative metabolites in Panax quinquefolius L

Panax quinquefolius L. has attracted extensive attention worldwide because of its prominent pharmacological properties on type 2 diabetes, cancers, central nervous system, and cardiovascular diseases. Ginsenosides are active phytochemicals of P. quinquefolius, which can be classified as propanaxdiol (PPD)-type, propanaxtriol (PPT)-type, oleanane-type, and ocotillol-type oligo-glycosides depending on the skeleton of aglycone. Recently, advanced analytical and isolated methods including ultra-performance liquid chromatography tandem with mass detector, preparative high-performance liquid chromatography, and high speed counter-current chromatography have been used to isolate and identify minor components in P. quinquefolius, which accelerates the clarification of the material basis. However, the poor bioavailability and undetermined bio-metabolism of most saponins have greatly hindered both the development of medicines and the identification of their real active constituents. Thus, it is essential to consider the bio-metabolism of constituents before and after absorption. In this review, we described the structures of minor ginsenosides in P. quinquefolius, including naturally occurring protype compounds and their in vivo metabolites. The preclinical and clinical pharmacological studies of the ginsenosides in the past few years were also summarized. The review will promote the reacquaint of minor saponins on the growing appreciation of their biological role in P. quinquefolius.

Role of Bioactive Constituents of Panax notoginseng in the Modulation of Tumorigenesis: A Potential Review for the Treatment of Cancer

Cancer is a leading cause of death, affecting people in both developed and developing countries. It is a challenging disease due to its complicated pathophysiological mechanism. Many anti-cancer drugs are used to treat cancer and reduce mortality rates, but their toxicity limits their administration. Drugs made from natural products, which act as multi-targeted therapy, have the ability to target critical signaling proteins in different pathways. Natural compounds possess pharmacological activities such as anti-cancer activity, low toxicity, and minimum side effects. Panax notoginseng is a medicinal plant whose extracts and phytochemicals are used to treat cancer, cardiovascular disorders, blood stasis, easing inflammation, edema, and pain. P. notoginseng's secondary metabolites target cancer's dysregulated pathways, causing cancer cell death. In this review, we focused on several ginsenosides extracted from P. notoginseng that have been evaluated against various cancer cell lines, with the aim of cancer treatment. Furthermore, an in vivo investigation of these ginsenosides should be conducted to gain insight into the dysregulation of several pathways, followed by clinical trials for the potential and effective treatment of cancer.

Panaxadiol as a major metabolite of AD-1 can significantly inhibit the proliferation and migration of breast cancer cells: In vitro and in vivo study

Previous studies have shown that 20 (R)-25-methoxyl-dammarane-3β, 12β, 20 triol (AD-1) can inhibit various cancer cell lines. This study aimed to explore the effect and mechanism of AD-1 metabolite M2 (Panaxadiol; PD) on breast cancer cells of nude mice. Five AD-1 metabolites were isolated and identified using various chromatographic techniques. PD was the main component. In vitro results showed that PD could inhibit the proliferation and migration of MDA-MB-231 cells by inducing G1-phase arrest. In addition, PD down-regulated the expression of Cyclin D1, cdk2, cdk4, cdk6, P-p38, and MMP9, and up-regulated p21 and p27. In vivo results showed that PD could effectively reduce the volume, weight, and migration of breast cancer Transcriptomics analyzed 491 differentially expressed genes by GO and KEGG enrichment. RT-PCR verification confirmed that the significant down-regulation of MMP9 was consistent with transcriptomics results. In further research showed that PD regulated the protein expression of P-p38 and MMP9 in MAPK pathway. In summary, in vivo and in vitro studies showed that PD significantly inhibit the occurrence and development of breast cancer, possibly through the MAPK pathway.

Integrative Management of Pancreatic Cancer (PDAC): Emerging Complementary Agents and Modalities

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. The standard first-line treatment for PDAC is gemcitabine chemotherapy which, unfortunately, offers only limited chance of a lasting cure. This review further evaluates the hypothesis that the effectiveness of gemcitabine can be improved by combining it with evidence-based complementary measures. Previously, supported by clinical trial data, we suggested that a number of dietary factors and nutraceuticals can be integrated with gemcitabine therapy. Here, we evaluate a further 10 agents for which no clinical trials have (yet) been carried out but there are promising data from in vivo and/or in vitro studies including experiments involving combined treatments with gemcitabine. Two groups of complementary agents are considered: Dietary factors (resveratrol, epigallocatechin gallate, vitamin B9, capsaicin, quercetin and sulforaphane) and nutraceutical agents (artemisinin, garcinol, thymoquinone and emodin). In addition, we identified seven promising agents for which there is currently only basic (mostly in vitro) data. Finally, as a special case of combination therapy, we highlighted synergistic drug combinations involving gemcitabine with "repurposed" aspirin or metformin. We conclude overall that integrated management of PDAC currently is likely to produce the best outcome for patients and for this a wide range of complementary measures is available.

1α,25-Dihydroxyvitamin D3 synergistically enhances anticancer effects of ginsenoside Rh2 in human prostate cancer cells

1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃, commonly known as calcitriol), the most active metabolite of vitamin D₃, and ginsenoside Rh2 can regulate cellular differentiation and proliferation proteins. The purpose of the present study was to assess the effect of 1,25(OH)₂D₃ on the anticancer activities of Rh2 in human prostate cancer cells such as androgen-dependent LNCaP and androgen-independent C4-2 in vitro. The effects of treatment with 1,25(OH)₂D₃ or Rh2, either alone or in combination, on prostate cancer cells were evaluated through tetrazolium-based cell viability assay, BrdU cell proliferation rate estimation assay, and Western blot protein expression analyses of nuclear receptors (androgen receptor and vitamin D receptors) and apoptotic proteins (Bcl-2, Bax, and Caspase 3). The Combination Indices (CI) and Dose Reduction Indices (DRI) of 1,25(OH)₂D₃ and Rh2 were calculated to determine synergistic anticancer activity using Calcusyn software (Biosoft, Cambridge, UK). The cell viability assay data indicate that Rh2 treatment alone inhibited cell viability in a concentration-dependent manner and the addition of 10 nM 1,25(OH)₂D₃ to Rh2 significantly enhanced its ability to reduce cell viability up to 80 % in both the cell lines. Similarly, addition of 10 nM 1,25(OH)₂D₃ to Rh2 significantly lowered its IC₅₀ values for cell proliferation from the range of 32-65 μM to 14-8 μM in LNCaP and C4-2 cells. In addition, protein expression analyses indicated that the combined treatment with Rh2 and 1,25(OH)₂D₃ led to greater downregulation of androgen receptor expression compared to single agent exposure. Similarly, the presence of 1,25(OH)₂D₃ synergistically increased the pro-apoptotic actions of Rh2 in both the cell lines. Overall, 1,25(OH)₂D₃ augments the Rh2-mediated anticancer effects through stimulating apoptosis and reduced cell proliferation which suggests that synergism of this combination may lead to potential lower need of the active vitamin D₃ and limited toxicity from it.

Targeting MDM2 for Neuroblastoma Therapy: In Vitro and In Vivo Anticancer Activity and Mechanism of Action

Simple Summary

Neuroblastoma is a malignant tumor of the sympathetic nervous system that causes aggressive disease in children. The overall survival rate of high-risk patients is very low, therefore developing effective and safe therapies for neuroblastoma is an urgent unmet medical need. The mouse double minute 2 (MDM2) homolog gene is amplified and overexpressed in neuroblastoma and contributes to the poor response to treatment and poor prognosis in patients with high-risk neuroblastoma. Therefore, targeting MDM2 provides a promising approach to neuroblastoma therapy, especially for advanced disease. In the present study, we tested a unique MDM2 inhibitor, SP141, for its therapeutic efficacy and safety in neuroblastoma tumor models. We found that SP141 has significant anti- neuroblastoma activity in cell culture and inhibits tumor growth in animal models of human neuroblastoma, without any noticeable host toxicity. These results provide the basis for targeting MDM2 to treat high-risk neuroblastoma.

Abstract

Background: Neuroblastoma is an aggressive pediatric solid tumor with an overall survival rate of <50% for patients with high-risk disease. The majority (>98%) of pathologically-diagnosed neuroblastomas have wild-type p53 with intact functional activity. However, the mouse double minute 2 (MDM2) homolog, an E3 ubiquitin ligase, is overexpressed in neuroblastoma and leads to inhibition of p53. MDM2 also exerts p53-independent oncogenic functions. Thus, MDM2 seems to be an attractive target for the reactivation of p53 and attenuation of oncogenic activity in neuroblastoma. Methods: In this study, we evaluated the anticancer activities and underlying mechanisms of action of SP141, a first-in-class MDM2 inhibitor, in neuroblastoma cell lines with different p53 backgrounds. The findings were confirmed in mouse xenograft models of neuroblastoma. Results: We demonstrate that SP141 reduces neuroblastoma cell viability, induces apoptosis, arrests cells at the G2/M phase, and prevents cell migration, independent of p53. In addition, in neuroblastoma xenograft models, SP141 inhibited MDM2 expression and suppressed tumor growth without any host toxicity at the effective dose. Conclusions: MDM2 inhibition by SP141 results in the inhibition of neuroblastoma growth and metastasis, regardless of the p53 status of the cells and tumors. These findings provide proof-of-concept that SP141 represents a novel treatment option for both p53 wild-type and p53 null neuroblastoma.

Targeting the p53-MDM2 pathway for neuroblastoma therapy: Rays of hope

Despite being the subject of extensive research and clinical trials, neuroblastoma remains a major therapeutic challenge in pediatric oncology. The p53 protein is a central safeguard that protects cells against genome instability and malignant transformation. Mutated TP53 (the gene encoding p53) is implicated in many human cancers, but the majority of neuroblastomas have wild type p53 with intact transcriptional function. In fact, the TP53 mutation rate does not exceed 1-2% in neuroblastomas. However, overexpression of the murine double minute 2 (MDM2) gene in neuroblastoma is relatively common, and leads to inhibition of p53. It is also associated with other non-canonical p53-independent functions, including drug resistance and increased translation of MYCN and VEGF mRNA. The p53-MDM2 pathway in neuroblastoma is also modulated at several different molecular levels, including via interactions with other proteins (MYCN, p14^ARF). In addition, the overexpression of MDM2 in tumors is linked to a poorer prognosis for cancer patients. Thus, restoring p53 function by inhibiting its interaction with MDM2 is a potential therapeutic strategy for neuroblastoma. A number of p53-MDM2 antagonists have been designed and studied for this purpose. This review summarizes the current understanding of p53 biology and the p53-dependent and -independent oncogenic functions of MDM2 in neuroblastoma, and also the regulation of the p53-MDM2 axis in neuroblastoma. This review also highlights the use of MDM2 as a molecular target for the disease, and describes the MDM2 inhibitors currently being investigated in preclinical and clinical studies. We also briefly explain the various strategies that have been used and future directions to take in the development of effective MDM2 inhibitors for neuroblastoma.

Anticancer property of ginsenoside Rh2 from ginseng

Ginseng has been used as a well-known traditional Chinese medicine since ancient times. Ginsenosides as its main active constituents possess a broad scope of pharmacological properties including stimulating immune function, enhancing cardiovascular health, increasing resistance to stress, improving memory and learning, developing social functioning and mental health in normal persons, and chemotherapy. Ginsenoside Rh2 (Rh2) is one of the major bioactive ginsenosides from Panax ginseng. When applied to cancer treatment, Rh2 not only exhibits the anti-proliferation, anti-invasion, anti-metastasis, induction of cell cycle arrest, promotion of differentiation, and reversal of multi-drug resistance activities against multiple tumor cells, but also alleviates the side effects after chemotherapy or radiotherapy. In the past decades, nearly 200 studies on Rh2 in the treatment of cancer have been published, however no specific reviews have been conducted by now. So the purpose of this review is to provide a systematic summary and analysis of the anticancer effects and the potential mechanisms of Rh2 extracted from Ginseng then give a future prospects about it. In the end of this paper the metabolism and derivatives of Rh2 also have been documented.

Effects of Ginseng Ingestion on Salivary Testosterone and DHEA Levels in Healthy Females: An Exploratory Study

Ginseng is a traditional herbal adaptogen that has been historically used in China and the Far East. Ginsenosides are the active component of ginseng known to exert several actions by targeting "multi-receptor systems", both extracellular and intracellular. In humans, ginseng effects remain unclear. This study aimed to investigate whether ginseng can influence salivary androgen levels (testosterone and dehydroepiandrosterone (DHEA)) in females. The study followed a parallel partially controlled design. Healthy women (n = 24) were recruited and divided into two groups (A = 20-32 and B = 38-50 years). Volunteers were asked to maintain a food diary pre and post ginseng consumption and collected four salivary samples (7 a.m., 9 a.m., 12 p.m., and 5 p.m.) before and after ingesting 75 mg red Korean ginseng extract per day for seven days. Testosterone and DHEA were then assayed by ELISA methods. Group A's mean daily salivary testosterone pre ginseng ingestion increased from 76.3 ± 16.6 to 98.4 ± 21.1 pg/mL post ginseng (p < 0.01) with significant difference at all time points, and mean daily salivary DHEA increased from 1.53 ± 0.63 to 1.98 ± 0.89 ng/mL post ginseng (p = 0.02). Group B's mean daily salivary testosterone pre ginseng ingestion was 61.2 ± 16.9 and post ginseng 68.1 ± 11.5 pg/mL (p = 0.132), and daily salivary DHEA increased from 0.91 ± 0.32 to 1.62 ± 0.49 ng/mL post ginseng (p = 0.014) with significant difference at all time points. In conclusion, it appears that ginseng intake significantly increased salivary testosterone levels in the younger women group, but only slightly in the older group. However, DHEA levels in the older women showed a marked and significant increase. These results suggest a potential role for ginseng in modulating salivary androgen levels and that such effect may be more evident in older women where the levels of androgens (DHEA) start to decline. However, it has to be stressed that our results are preliminary and further properly controlled trials are justified.

Natural Product Ginsenoside 20(S)-25-Methoxyl-Dammarane-3β, 12β, 20-Triol in Cancer Treatment: A Review of the Pharmacological Mechanisms and Pharmacokinetics

Panax ginseng has been used as an herbal medicine for thousands of years. Most of its pharmacological effects are attributed to its constituent ginsenosides, including 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol (20(S)-25-OCH₃-PPD), which is one of the protopanaxadiol type ginsenosides. It has been found to exhibit anticancer effects by interacting with multiple pharmacological pathways, such as the Wnt/β-catenin, MDM2, ERK/MAPK, and STAT3 signaling pathways. However, its therapeutic potential could be limited by its low bioavailability mainly due to its low aqueous solubility. Thus, several studies have been conducted on its pharmacokinetics and its delivery systems, so as to increase its oral bioavailability. In this review, comprehensive information on its varying pharmacological pathways in cancer, as well as its pharmacokinetic behavior and pharmaceutical strategies, is provided. This information would be useful in the understanding of its diverse mechanisms and pharmacokinetics as an anticancer drug, leading to the design of superior 20(S)-25-OCH₃-PPD-containing formulations that maximize its therapeutic potential.

Prevention of prostate cancer by natural product MDM2 inhibitor GS25: in vitro and in vivo activities and molecular mechanisms

Prostate cancer remains a major health problem in the USA and worldwide. There is an urgent need to develop novel approaches to preventing primary and metastatic prostate cancer. We have identified 25-OCH3-protopanaxadiol (GS25), the most active ginsenoside that has been identified so far; it has potent activity against human cancers, including prostate cancer. However, it has not been proven if GS25 could be a safe and effective agent for cancer prevention. In this study, we used the TRAMP model and clearly demonstrated that GS25 inhibited prostate tumorigenesis and metastasis with minimal host toxicity. Mechanistically, GS25 directly bound to the RING domain of MDM2, disrupted MDM2-MDMX binding and induced MDM2 protein degradation, resulting in strong inhibition of prostate cancer cell growth and metastasis, independent of p53 and androgen receptor status. In conclusion, our in vitro and in vivo data support the potential use of GS25 in prevention of primary and metastatic prostate cancer.

Genotoxicity and subchronic toxicological study of a novel ginsenoside derivative 25-OCH3-PPD in beagle dogs

Background

Ginsenosides have been widely used clinically for many years and were regarded as very safe. However, a few researches on the toxicities of these kinds of agents showed that some ginsenosides may have side-effect on the rats or dogs. So it is extremely necessary to further clarify the potential toxicity of ginsenosides. This study was carried out to investigate long-term toxicity and genotoxicity of 25-methoxydammarane-3, 12, 20-triol (25-OCH₃-PPD), a new derivative of ginsenoside, in beagle dogs.

Methods

Twenty-four beagle dogs were divided randomly into four treatment groups and repeatedly orally administered with 25-OCH₃-PPD capsule at 60, 120, and 240 mg/kg/day for 91 consecutive days. Ames, micronucleus, and chromosomal aberration tests were established to analyze the possible genotoxicity of 25-OCH₃-PPD.

Results

There was no 25-OCH₃-PPD–induced systemic toxicity in beagle dogs at any doses. The level of 25-OCH₃-PPD at which no adverse effects were observed was found to be 240 mg/kg/day. The result of Ames test showed that there was no significant increase in the number of revertant colonies of 25-OCH₃-PPD administrated groups compared to the vehicle control group. There were also no significant differences between 25-OCH₃-PPD administrated groups at all dose levels and negative group in the micronucleus test and chromosomal aberration assay.

Conclusion

The highest dose level of 25-OCH₃-PPD at which no adverse effects were observed was found to be 240 mg/kg per day, and it is not a genotoxic agent either in somatic cells or germs cells. 25-OCH₃-PPD is an extremely safe candidate compound for antitumor treatment.

Conjugation of Ginsenoside with Dietary Amino Acids: A Promising Strategy To Suppress Cell Proliferation and Induce Apoptosis in Activated Hepatic Stellate Cells

Ginseng has been widely used as a functional food in the world because of its well-defined health benefits. Previous studies have confirmed that AD-1, a new ginsenoside derived from ginseng, can ameliorate thioacetamide-induced liver injury and fibrosis in mice. Simultaneously, amino acid supplementation is getting more attention as an important adjuvant therapy in the improvement of hepatopathy. The aim of this study was to conjugate AD-1 with several selected amino acids and investigate the cytotoxicity of the obtained conjugates in activated t-HSC/Cl-6 cells and normal human liver cells (LO2). Structure-activity relationships of conjugates and underlying mechanisms of the effect are also explored. The results indicated that conjugate 7c remarkably inhibited cell proliferation in activated t-HSC/Cl-6 cells (IC₅₀ = 3.8 ± 0.4 μM) and appeared to be nontoxic to LO2. Besides, conjugate 7c had a relatively good plasma stability. Further study demonstrated that inducing S-phase arrest and activation of mitochondrial-mediated apoptosis were included in the mechanisms underlying the efficiency of conjugate 7c. These findings provided further insight into designing functional foods (ginsenoside and amino acid) for the application in prevention or improvement of liver fibrosis.

New perspective on the metabolism of AD-1 in vivo: Characterization of a series of dammarane-type derivatives with novel metabolic sites and anticancer mechanisms of active oleanane-type metabolites

20(R)-25-methoxyl-dammarane-3β,12β,20-triol (AD-1, CN Patent: 201010107476.7) is a novel derivative of dammarane-type ginsenoside. AD-1 has been shown to inhibit cancer cell proliferation without significant host toxicity in vivo, and has excellent development potential as a new anti-cancer agent. This study was designed systematically to explore the metabolic pathway of ginseng sapogenins. The metabolism of drugs in the body is a complex biotransformation process where drugs are structurally modified to different molecules (metabolites) through various metabolizing enzymes. The compounds responsible for the effects of orally administered ginseng are believed to be metabolites produced in the gastrointestinal tract, so understanding the metabolism of the drug candidate can help to optimize its pharmacokinetics. In this study, faeces samples were collected and extracted after oral administration of AD-1. The 16 metabolites of AD-1 were isolated and identified for the first time with various chromatographic techniques, including semi-preparative high performance liquid chromatography, nuclear magnetic resonance spectroscopy, and mass spectrometry; of these 16 metabolites, 10 were novel compounds. We first discovered the biotransformation of dammarane-type sapogenins into oleanane-type sapogenins in rats and found a series of metabolites that changed, mainly at C-25 and C-29. This study provides new ideas for the metabolic pathway of ginseng sapogenins. The isolated compounds were screened for their effect on the viability and proliferation against cancer cell lines (Human A549, MCF-7, HELA, HO-8901 and U87). The discovery of novel active metabolites 3β,12β,21α,22β-Hydroxy-24-norolean-12-ene (M6) may lead to a new or improved drug candidate. For one, M6 could inhibit the growth of all the tested cancer cells. Among the tested cell lines, M6 exhibited the most remarkable inhibitory effect on ovarian cancer HO-8901 cells, with IC50 value of 2.086 μM. On this basis, we studied the anticancer mechanisms of M6. The results indicated that the pro-apoptotic feature of M6 acts via a mitochondrial pathway. Our results indicated that M6 exhibited a higher inhibitory effect on cancer-cell proliferation than AD-1 by inducing cell apoptosis. Our work provides data for future investigations on the metabolic mechanism of AD-1 in vivo and the potential for future research on developing a new drug.

Anticancer activity and mechanism of total saponins from the residual seed cake of Camellia oleifera Abel. in hepatoma-22 tumor-bearing mice

Total saponins from the residual seed cake of Camellia oleifera Abel. exhibited beneficial properties on anticancer activity in hepatoma-22 tumor-bearing mice and represents a promising species for food applications.

Saponins as modulators of nuclear receptors

As plant-derived natural products, saponins have been widely applied for the dietary modification of metabolic syndrome. However, the underlying mechanisms of their preventive and therapeutic effects are still largely unclear. Nuclear receptors have been identified as potential pharmaceutical targets for treating various types of metabolic disorders. With similar structure to endogenous hormones, several saponins may serve as selective ligands for nuclear receptors. Recently, a series of saponins are proved to exert their physiological activities through binding to nuclear receptors. This review summarizes the biological and pharmacological activities of typical saponins mediated by some of the most well described nuclear receptors, including the classical steroid hormone receptors (ER, GR, MR, and AR) and the adopted orphan receptors (PPAR, LXR, FXR, and PXR).

Natural products targeting the p53-MDM2 pathway and mutant p53: Recent advances and implications in cancer medicine

The p53 tumor suppressor plays a major role in controlling the initiation and development of cancer by regulating cell cycle arrest, apoptosis, senescence, and DNA repair. The MDM2 oncogene is a major negative regulator of p53 that inhibits the activity of p53 and reduces its protein stability. MDM2, p53, and the p53-MDM2 pathway represent well-documented targets for preventing and/or treating cancer. Natural products, especially those from medicinal and food plants, are a rich source for the discovery and development of novel therapeutic and preventive agents against human cancers. Many natural product-derived MDM2 inhibitors have shown potent efficacy against various human cancers. In contrast to synthetic small-molecule MDM2 inhibitors, the majority of which have been designed to inhibit MDM2-p53 binding and activate p53, many natural product inhibitors directly decrease MDM2 expression and/or MDM2 stability, exerting their anticancer activity in both p53-dependent and p53-independent manners. More recently, several natural products have been reported to target mutant p53 in cancer. Therefore, identification of natural products targeting MDM2, mutant p53, and the p53-MDM2 pathway can provide a promising strategy for the development of novel cancer chemopreventive and chemotherapeutic agents. In this review, we focus our discussion on the recent advances in the discovery and development of anticancer natural products that target the p53-MDM2 pathway, emphasizing several emerging issues, such as the efficacy, mechanism of action, and specificity of these natural products.

Ginsenoside 25-OCH3-PPD Promotes Activity of LXRs To Ameliorate P2X7R-Mediated NLRP3 Inflammasome in the Development of Hepatic Fibrosis

Ginseng is widely used in energy drinks, dietary supplements, and herbal medicines, and its pharmacological actions are related with energy metabolism. As an important modulating energy metabolism pathway, liver X receptors (LXRs) can promote the resolving of hepatic fibrosis and inflammation. The present study aims to evaluate the regulation of 25-OCH₃-PPD, a ginsenoside isolated from Panax ginseng, against hepatic fibrosis and inflammation in thioacetamide (TAA)-stimulated mice by activating the LXRs pathway. 25-OCH₃-PPD decreases serum ALT/AST levels and improves the histological pathology of liver in TAA-induced mice; attenuates transcripts of pro-fibrogenic markers associated with hepatic stellate cell activation; attenuates the levels of pro-Inflammatory cytokines and blocks apoptosis happened in liver; inhibits NLRP3 inflammasome by affecting P2X7R activation; and regulates PI3K/Akt and LKB1/AMPK-SIRT1. 25-OCH₃-PPD also facilitates LX25Rs and FXR activities decreased by TAA stimulation. 25-OCH₃-PPD also decreases α-SMA via regulation of LXRs and P2X7R-NLRP3 in vitro. Our data suggest the possibility that 25-OCH₃-PPD promotes activity of LXRs to ameliorate P2X7R-mediated NLRP3 inflammasome in the development of hepatic fibrosis.

20(S)-protopanaxadiol regio-selectively targets androgen receptor: anticancer effects in castration-resistant prostate tumors

We have explored the effects of 20(S)-protopanaxadiol (aPPD), a naturally derived ginsenoside, against androgen receptor (AR) positive castration resistant prostate cancer (CRPC) xenograft tumors and have examined its interactions with AR. In silico docking studies for aPPD binding to AR, alongside transactivation bioassays and in vivo efficacy studies were carried out in the castration-resistant C4-2 xenograft model. Immunohistochemical (IHC) and Western blot analyses followed by evaluation of AR, apoptotic, cell cycle and proliferative markers in excised tumors was performed. The growth of established CRPC tumors was inhibited by 53% with aPPD and a corresponding decrease in serum PSA was seen compared to controls. The IHC data revealed that Ki-67 was significantly lower for aPPD treated tumors and was associated with elevated p21 and cleaved caspase-3 expression, compared to vehicle treatment. Furthermore, aPPD decreased AR protein expression in xenograft tumors, while significantly upregulating p27 and Bax protein levels. In vitro data supporting this suggests that aPPD binds to and significantly inhibits the N-terminal or the DNA binding domains of AR. The AR androgen binding site docking score for androgen (dihydrotestosterone) was −11.1, while that of aPPD was −7.1. The novel findings described herein indicate aPPD potently inhibits PCa in vivo partly via inhibition of a site on the AR N-terminal domain. This manifested as cell cycle arrest and concurrent induction of apoptosis via an increase in Bax, cleaved-caspase-3, p27 and p21 expression.

Polymorphic characterization and bioavailability of 20(R)-25-methoxyl-dammarane-3β,12β,20-triol, a novel dammarane triterpenoid saponin, as anticancer agents

This research, for the first time, obtained and reported three novel Form I, Form II, and Form III of 20(R)-25-methoxyl-dammarane-3β,12β,20-triol polymorphs, which were distinguished by PXRD, IR, DSC, and SEM. This study firstly exploited a rapid and feasible UHPLC-ESI-MS/MS method to determine plasma levels of 20(R)-25-OCH3-PPD within 4.5min. The composition of mobile phase was acetonitrile and 5mM ammonium acetate water (85:15, v/v) at a flow rate of 0.2mL/min on the BEH C18 Column (2.1mm×50mm, 1.7μm). The approach enhanced the efficiency of analysis compared to reported methods, making a 3-fold reduction in runtimes. The research exhibited that optimal crystal Form I displays higher bioavailability (P<0.05) compared to the other crystal forms. These findings hold great significance in the early research stages of 20(R)-25-OCH3-PPD polymorphs.

Experimental Therapy of Advanced Breast Cancer: Targeting NFAT1-MDM2-p53 Pathway

Advanced breast cancer, especially advanced triple-negative breast cancer, is typically more aggressive and more difficult to treat than other breast cancer phenotypes. There is currently no curable option for breast cancer patients with advanced diseases, highlighting the urgent need for novel treatment strategies. We have recently discovered that the nuclear factor of activated T cells 1 (NFAT1) activates the murine double minute 2 (MDM2) oncogene. Both MDM2 and NFAT1 are overexpressed and constitutively activated in breast cancer, particularly in advanced breast cancer, and contribute to its initiation, progression, and metastasis. MDM2 regulates cancer cell proliferation, cell cycle progression, apoptosis, migration, and invasion through both p53-dependent and -independent mechanisms. We have proposed to target the NFAT1-MDM2-p53 pathway for the treatment of human cancers, especially breast cancer. We have recently identified NFAT1 and MDM2 dual inhibitors that have shown excellent in vitro and in vivo activities against breast cancer, including triple-negative breast cancer. Herein, we summarize recent advances made in the understanding of the oncogenic functions of MDM2 and NFAT1 in breast cancer, as well as current targeting strategies and representative inhibitors. We also propose several strategies for inhibiting the NFAT1-MDM2-p53 pathway, which could be useful for developing more specific and effective inhibitors for breast cancer therapy.

One-pot synthesis, anti-tumor evaluation and structure-activity relationships of novel 25-OCH3-PPD derivatives

Based on the fact that 25-OCH₃-PPD, a natural ginsengenin isolated from the leaves of Panax ginseng, is a promising lead compound, novel 25-OCH₃-PPD derivatives were synthesized to find more potent anti-tumor agents by a simple and facile synthetic method. These derivatives were classified into three types and screened for their cytotoxic activities against seven human cancer cell lines. Compared with 25-OCH₃-PPD, compounds a5, a7, b5 and b7 exhibited higher anti-tumor activities on all tested cell lines with almost 5-fold to 15-fold increases. In particular, compound a7 showed the greatest cytotoxic activity against α-2 cells (IC₅₀ = 2.4 ± 0.4 μM). The preliminary study on the mechanisms indicated that compound a7 could induce α-2 cell apoptosis. Structure-activity relationships demonstrated that the carbon-carbon double bond at the C-20 position could enhance the antiproliferative activity. In conclusion, the novel derivatives a5, a7, b5 and b7 could be further studied as potential candidates for the treatment of cancer. This research provides a theoretical reference for the exploration of new antiproliferative agents.

Water-soluble derivatives of 25-OCH3-PPD and their anti-proliferative activities

(20R)-25-Methoxyl-dammarane-3β,12β,20-triol (25-OCH3-PPD, AD-1) is a dammarane-type sapogenin showing anti-tumor potential. In the search for new anti-tumor agents with higher potency than our previously identified compound 25-OCH3-PPD, 11 novel sulfamic acid and diacid derivatives that could improve water solubility and contribute to good drug potency and pharmacokinetic profiles were designed and synthesized. Their in vitro anti-tumor activities in MCF-7, A-549, HCT-116, and BGC-823 cell lines and one normal cell line were tested by standard MTT assay. Results showed that compared with compound 25-OCH3-PPD, compounds 1, 4, and 5 exhibited higher cytotoxic activity on almost all cell lines, together with lower toxicity in the normal cell. In particular, compound 1 exhibited the best anti-tumor activity in the in vitro assays. The water solubility of 25-OCH3-PPD and its derivatives was tested and the results showed that the solubility of 25-OCH3-PPD sulfamic acid and diacid derivatives were better than that of 25-OCH3-PPD in water, which may provide valuable data for the research and development of new anti-tumor agents.

Ginsenoside Rh2 and Rg3 inhibit cell proliferation and induce apoptosis by increasing mitochondrial reactive oxygen species in human leukemia Jurkat cells

Ginsenoside Rh2 (GRh2) and ginsenoside Rg3 (GRg3) are primary bioactive components in Panax ginseng. The present study aimed to investigate the underlying mechanisms of apoptotic cell-death induced by GRh2 and GRg3 in human leukemia Jurkat cells. The Cell Counting kit-8 assay was used to determine cell proliferation. Apoptosis was detected by nuclear morphologic observation by Hoechst 33342 staining and Annexin V-allophycocyanin and 7-amino-actinomycin D assay. mitoTEMPO, a mitochondrial reactive oxygen species (ROS) scavenger, was used to examine the effects of mitochondrial ROS on cell viability and mitochondrial membrane potential (MMP). Finally, the expression levels of numerous mitochondrial-associated apoptosis proteins were assessed by western blot analysis. These results demonstrated that GRh2 and GRg3 inhibited cell growth and induced apoptosis, and that GRh2 had greater cytotoxicity than GRg3. GRh2 induced generation of more mitochondrial ROS compared with GRg3 in Jurkat cells; however, this effect was ameliorated by subsequent treatment with mitoTEMPO. Furthermore, excess mitochondrial ROS induced by GRh2 was more potent than GRg3 in inhibiting cell proliferation and reducing MMP. In addition, expression levels of apoptosis-associated proteins were significantly increased in Jurkat cells treated with GRh2 than GRg3. In conclusion, these findings suggested that GRh2 and GRg3 induce mitochondrial-associated apoptosis by increasing mitochondrial ROS in human leukemia Jurkat cells. GRh2 may more effectively inhibit cell growth and accelerate apoptosis than GRg3. This study provides a potential novel strategy for the treatment of acute lymphoblastic leukemia.

Ginsenoside PPD's Antitumor Effect via Down-Regulation of mTOR Revealed by Super-Resolution Imaging

Derived from Panax ginseng, the natural product 20(S)-Protopanaxadiol (PPD) has been reported for its cytotoxicity against several cancer cell lines. The molecular mechanism is, however, not well understood. Here we show that PPD significantly inhibits proliferation, induces apoptosis and causes G2/M cell cycle arrest in human laryngeal carcinoma cells (Hep-2 cells). PPD also decreases the levels of proteins related to cell proliferation. Moreover, PPD-induced apoptosis is characterized by a dose-dependent down-regulation of Bcl-2 expression and up-regulation of Bax, and is accompanied by the activation of Caspase-3 as well. Further molecular mechanism is revealed by direct stochastic optical reconstruction microscopy (dSTORM)—a novel high-precision localization microscopy which enables effective resolution down to the order of 10 nm. It shows the expression and spatial arrangement of mTOR and its downstream effectors, demonstrating that this ginsenoside exerts its excellent anticancer effects via down-regulation of mTOR signaling pathway in Hep-2 cells. Taken together, our findings elucidate that the antitumor effect of PPD is associated with its regulation of mTOR expression and distribution, which encourages further studies of PPD as a promising therapeutic agent against laryngeal carcinoma.

Stereoselective pharmacokinetics of 25-methoxyl-dammarane-3β,12β,20-triol and its active demethyl-metabolite epimers in rats after oral and intravenous administration

Stereoselectivity of ginsenosides produced from the stereogenic carbon-20 has been proved to be closely related to drug action including pharmacodynamics and pharmacokinetics. 25-Methoxydammarane-3,12,20-triol (25-OCH₃-PPD) and 25-hydoxyprotopanaxadiol (25-OH-PPD) are novel protopanaxadiol-type (PPD) sapogenins. 25-OH-PPD was also the in vivo bioactive demethyl-metabolite of 25-OCH₃-PPD. The study aimed to investigate the influence of 20(R/S)-configuration on the pharmacokinetics of 20(R/S)-25-OCH₃-PPD epimers and 20(R/S)-25-OH-PPD epimers. When rats were given 20(R/S)-25-OCH₃-PPD epimers intravenously, the pharmacokinetic profiles of both epimers of 25-OCH₃-PPD were similar, while the pharmacokinetic behaviors of their demethyl-metabolites were obviously different. After rats received an oral dose of 20(R/S)-25-OCH₃-PPD epimers, the C_max and AUC values of 20(S)-25-OCH₃-PPD were at least 100 times higher than those of 20(R)-25-OCH₃-PPD. Stereoselective pharmacokinetics of 25-OH-PPD was observed in rats after i.v. and i.g. administration of 20(R/S)-25-OH-PPD epimers. In vitro metabolic kinetics results indicated that faster hepatic metabolism of R-epimer should be one of the crucial factors accounting for the stereospecific pharmacokinetics of 25-OCH₃-PPD and 25-OH-PPD epimers.

Saponins from Chinese Medicines as Anticancer Agents

Saponins are glycosides with triterpenoid or spirostane aglycones that demonstrate various pharmacological effects against mammalian diseases. To promote the research and development of anticancer agents from saponins, this review focuses on the anticancer properties of several typical naturally derived triterpenoid saponins (ginsenosides and saikosaponins) and steroid saponins (dioscin, polyphyllin, and timosaponin) isolated from Chinese medicines. These saponins exhibit in vitro and in vivo anticancer effects, such as anti-proliferation, anti-metastasis, anti-angiogenesis, anti-multidrug resistance, and autophagy regulation actions. In addition, related signaling pathways and target proteins involved in the anticancer effects of saponins are also summarized in this work.

Effects of ginseng on two main sex steroid hormone receptors: estrogen and androgen receptors

Ginseng has been used in China for at least two millennia and is now popular in over 35 countries. It is one of the world's popular herbs for complementary and alternative medicine and has been shown to have helpful effects on cognition and blood circulation, as well as anti-aging, anti-cancer, and anti-diabetic effects, among many others. The pharmacological activities of ginseng are dependent mainly on ginsenosides. Ginsenosides have a cholesterol-like four trans-ring steroid skeleton with a variety of sugar moieties. Nuclear receptors are one of the most important molecular targets of ginseng, and reports have shown that members of the nuclear receptor superfamily are regulated by a variety of ginsenosides. Here, we review the published literature on the effects of ginseng and its constituents on two main sex steroid hormone receptors: estrogen and androgen receptors. Furthermore, we discuss applications for sex steroid hormone receptor modulation and their therapeutic efficacy.

Anticancer Activities of Protopanaxadiol- and Protopanaxatriol-Type Ginsenosides and Their Metabolites

Recently, most anticancer drugs are derived from natural resources such as marine, microbial, and botanical sources, but the low success rates of chemotherapies and the development of multidrug resistance emphasize the importance of discovering new compounds that are both safe and effective against cancer. Ginseng types, including Asian ginseng, American ginseng, and notoginseng, have been used traditionally to treat various diseases, due to their immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Accumulating reports have shown that ginsenosides, the major active component of ginseng, were helpful for tumor treatment. 20(S)-Protopanaxadiol (PDS) and 20(S)-protopanaxatriol saponins (PTS) are two characteristic types of triterpenoid saponins in ginsenosides. PTS holds capacity to interfere with crucial metabolism, while PDS could affect cell cycle distribution and prodeath signaling. This review aims at providing an overview of PTS and PDS, as well as their metabolites, regarding their different anticancer effects with the proposal that these compounds might be potent additions to the current chemotherapeutic strategy against cancer.

Oral nano-delivery of anticancer ginsenoside 25-OCH3-PPD, a natural inhibitor of the MDM2 oncogene: Nanoparticle preparation, characterization, in vitro and in vivo anti-prostate cancer activity, and mechanisms of action

The Mouse Double Minute 2 (MDM2) oncogene plays a critical role in cancer development and progression through p53-dependent and p53-independent mechanisms. Both natural and synthetic MDM2 inhibitors have been shown anticancer activity against several human cancers. We have recently identified a novel ginsenoside, 25-OCH3-PPD (GS25), one of the most active anticancer ginsenosides discovered thus far, and have demonstrated its MDM2 inhibition and anticancer activity in various human cancer models, including prostate cancer. However, the oral bioavailability of GS25 is limited, which hampers its further development as an oral anticancer agent. The present study was designed to develop a novel nanoparticle formulation for oral delivery of GS25. After GS25 was successfully encapsulated into PEG-PLGA nanoparticles (GS25NP) and its physicochemical properties were characterized, the efficiency of MDM2 targeting, anticancer efficacy, pharmacokinetics, and safety were evaluated in in vitro and in vivo models of human prostate cancer. Our results indicated that, compared with the unencapsulated GS25, GS25NP demonstrated better MDM2 inhibition, improved oral bioavailability and enhanced in vitro and in vivo activities. In conclusion, the validated nano-formulation for GS25 oral delivery improves its molecular targeting, oral bioavailability and anticancer efficacy, providing a basis for further development of GS25 as a novel agent for cancer therapy and prevention.

Identification of lineariifolianoid A as a novel dual NFAT1 and MDM2 inhibitor for human cancer therapy

There is an increasing interest in development of novel anticancer agents that target oncogenes. We have recently discovered that nuclear factor of activated T cells 1 (NFAT1) is a novel regulator of the Mouse Double Minute 2 (MDM2) oncogene and the NFAT1-MDM2 pathway has been implicated in human cancer development and progression, justifying that targeting the NFAT1-MDM2 pathway could be a novel strategy for discovery and development of novel cancer therapeutics. The present study was designed to examine the anticancer activity and underlying mechanisms of action of lineariifolianoid A (LinA), a novel natural product inhibitor of the NFAT1-MDM2 pathway. The cytotoxicity of LinA was first tested in various human cancer cell lines in comparison with normal cell lines. The results showed that the breast cancer cells were highly sensitive to LinA treatment. We next demonstrated the effects of LinA on cell proliferation, colony formation, cell cycle progression, and apoptosis in breast cancer MCF7 and MDA-MB-231 cells, in dose-dependent and p53-independent manners. LinA also inhibited the migration and invasion of these cancer cells. Our mechanistic studies further indicated that its anticancer activities were attributed to its inhibitory effects on the NFAT1-MDM2 pathway and modulatory effects on the expression of key proteins involved in cell cycle progression, apoptosis, and DNA damage. In summary, LinA is a novel NFAT1-MDM2 inhibitor and may be developed as a preventive and therapeutic agent against human cancer.

20(S)-ginsenoside Rh2 inhibits the proliferation and induces the apoptosis of KG-1a cells through the Wnt/β-catenin signaling pathway

Previous research has shown that total saponins of Panax ginseng (TSPG) and other ginsenoside monomers inhibit the proliferation of leukemia cells. However, the effect has not been compared among them. Cell viability was determined by Cell Counting Kit-8 assay, and ultra-structural characteristics were observed under transmission electron microscopy. Cell cycle distribution and apoptosis were determined by flow cytometry (FCM). Real-time fluorescence quantitative‑PCR, western blotting and immunofluorescence were used to measure the expression of β-catenin, TCF4, cyclin D1 and NF-κBp65. β-catenin/TCF4 target gene transcription were observed by ChIP-PCR assay. We found that 20(S)-ginsenoside Rh2 [(S)Rh2] inhibited the proliferation of KG-1a cells more efficiently than the other monomers. Moreover, (S)Rh2 arrested KG-1a cells in the G0/G1 phase and induced apoptosis. In addition, the levels of β-catenin, TCF4, cyclin D1 mRNA and protein were decreased. The ChIP-PCR showed that (S)Rh2 downregulated the transcription of β-catenin/TCF4 target genes, such as cyclin D1 and c-myc. These results indicated that (S)Rh2 induced cell cycle arrest and apoptosis through the Wnt/β-catenin signaling pathway, demonstrating its potential as a chemotherapeutic agent for leukemia therapy.

Calcitriol and 20(S)-protopanaxadiol synergistically inhibit growth and induce apoptosis in human prostate cancer cells

The potential cancer preventive roles of calcitriol, the dihydroxylated metabolite of Vitamin D3, as well as 20(S)-protopanaxadiol (aPPD), the aglycone of the protopanaxadiol family of ginsenosides, have gained much attention in recent years for the prevention/treatment of prostate cancer (PCa). In the present study, we evaluated the anticancer and chemosensitization effects of calcitriol at clinically relevant concentrations and aPPD, either alone or in combination, in two well-characterized human PCa cell lines: androgen-sensitive non-metastatic LNCaP cells and androgen-independent metastatic C4-2 cells. The effects of the treatments on PCa cell viability and proliferation rates were evaluated by MTS and Brdu assays, respectively. Combination Indices (CI) and Dose Reduction Indices (DRI) were estimated to assess synergistic anticancer activity using Calcusyn software (Biosoft, Cambridge, UK). Then, we determined the potential Pharmacodynamic interaction mechanisms as follows: The protein expression levels of the genes those are known to control cell cycle (cyclin D1 and cdk2); apoptosis (Bcl-2, Bax, and Capspases 3), androgen receptor and Vitamin D receptors were examined upon combinational treatment. The cell viability assay data show that addition of 10nM calcitriol to aPPD significantly lowered its IC50 values from the range of 41-53μM to 13-23μM, in LNCaP and C4-2 prostate cancer cells. The cell proliferation rate was significantly lower for combination treatments compared to the cells treated with aPPD alone. Similarly, Western blot results indicate that aPPD significantly upregulated Vitamin D receptor (VDR) expression, while calcitriol further enhanced the ability of aPPD to induce pro-apoptotic BAX, increased cleaved caspase-3 and downregulate cdk2 protein levels. Thus, the pharmacodynamic interaction between aPPD and calcitriol in impacting growth inhibition and apoptosis appears to be synergistic in nature. In conclusion, calcitriol sensitizes PCa cells to aPPD-mediated anticancer effects by enhancing its ability to induce apoptosis and reduce cell proliferation, and this synergism may limit calcitriol toxicity by facilitating the use of lower calcitriol doses. The associated increase in VDR expression and calcitriol half-life may be mechanistically associated with this sensitization effect.

Oral subchronic toxicity evaluation of a novel antitumor agent 25-methoxydammarane-3, 12, 20-triol from Panax notoginseng in Sprague-Dawley rats

Panax notoginseng and its main active ingredients ginsenosides have long been used as medicines and food additives in China. Comparing with the extensive uses and active researches of P. notoginseng and its products, the side effect and probable toxicity were rare. 25-Methoxydammarane-3,12,20-triol (25-OCH3-PPD), a novel dammarane-type triterpene sapogenin that was first isolated from the extract of P. notoginseng, was proven to have strong antitumor activities against prostate cancer, breast cancer and lung cancer. The aim of the present study was to investigate the potential subchronic toxicity of 25-OCH3-PPD after it was repeatedly orally administered to Sprague-Dawley rats (5/sex/group/each time-point) at dose levels of 0, 150, 300 or 600 mg/kg/day for 13 weeks and 4-week recovery. No mortality and treatment-related toxicity effects were observed as a result of the administration of 25-OCH3-PPD at any dose level (150, 300 and 600 mg/kg) for 92 consecutive days. Although there were some statistical changes, such as increased weights in female rats and decreased organ weights and coefficients of the liver, spleen, kidney, and adrenal gland compared with the control group at the corresponding time, the autopsy and histopathological examination of the target organs did not show any abnormal responses. As a result, 25-OCH3-PPD was well tolerated by SD rat at doses of up to 600 mg/kg and that it is a potential candidate for therapeutic use.