Saikosaponin‑d inhibits proliferation of DU145 human prostate cancer cells by inducing apoptosis and arresting the cell cycle at G0/G1 phase

Research progress on the molecular mechanisms of Saikosaponin D in various diseases (Review)

Bupleurum, a Traditional Chinese Medicine (TCM) herb, is widely used in China and other Asian countries to manage chronic liver inflammation and viral hepatitis. Saikosaponin D (SSD), a triterpenoid saponin extracted from Bupleurum, exhibits extensive pharmacological properties, including anti‑inflammatory, antioxidant, anti‑apoptotic, anti‑fibrotic and anti‑cancer effects, making it a therapeutic candidate for numerous diseases. Clarifying the targets and molecular mechanisms underlying TCM compounds is essential for scientifically validating TCM's therapeutic roles in disease prevention and treatment, as well as for identifying novel therapeutic targets and lead compounds. This analysis comprehensively examines SSD's mechanisms across various conditions, such as myocardial injury, pulmonary diseases, hepatic disorders, renal pathologies, neurological disorders, diabetes and cancer. In addition, challenges and potential solutions encountered in SSD research are addressed. SSD is posited as a promising monomer for multifaceted therapeutic applications and this article aims to enhance researchers' understanding of the current landscape of SSD studies, offering strategic insights to guide future investigations.

Saikosaponin-b2 Regulates the Proliferation and Apoptosis of Liver Cancer Cells by Targeting the MACC1/c-Met/Akt Signalling Pathway

Saikosaponin-b2 (SS-b2), an active ingredient derived from the root of Radix Bupleuri, possesses antitumour, anti-inflammatory, antioxidative and hepatoprotective properties. We investigated the inhibition of tumour proliferation by SS-b2 and the underlying molecular mechanisms, including the MACC1/p-c-Met/p-Akt pathway expression in HepG2 liver cancer cells and H22 tumour-bearing mice. Animal experiments showed that SS-b2 significantly decreased the levels of MACC1, p-c-MET and p-Akt in tumour tissue transplanted with H22 liver cancer cells in mice, while it increased the expression of p-BAD. The results also revealed a concentration-dependent suppression of MACC1, p-c-Met and p-Akt expression in the SS-b2 treatment group compared with the control group. Additionally, the suppression of MACC1 activation by SS-b2 resulted in a reduction in the viability and proliferation of HepG2 liver cancer cells, and this reduction was comparable to that by doxorubicin (DOX). This suggests that SS-b2 has significant efficacy in liver cancer, comparable to DOX. Meanwhile, Annexin V-FITC/PI staining and western blot analysis of cleaved caspase 9 and cleaved caspase 3 demonstrated that SS-b2 induced apoptosis of HepG2 liver cancer cells. These findings provide experimental evidence suggesting that SS-b2 is a promising anticancer agent for liver cancer.

Molecular mechanism of Saikosaponin-d in the treatment of gastric cancer based on network pharmacology and in vitro experimental verification

The study aimed to utilize network pharmacology combined with cell experiments to research the mechanism of action of Saikosaponin-d in the treatment of gastric cancer. Drug target genes were obtained from the PubChem database and the Swiss Target Prediction database. Additionally, target genes for gastric cancer were obtained from the GEO database and the Gene Cards database. The core targets were then identified and further analyzed through gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and GESA enrichment. The clinical relevance of the core targets was assessed using the GEPIA and HPA databases. Molecular docking of drug monomers and core target proteins was performed using Auto Duck Tools and Pymol software. Finally, in vitro cellular experiments including cell viability, apoptosis, cell scratch, transwell invasion, transwell migration, qRT-PCR, and Western blot were conducted to verify these findings of network pharmacology. The network pharmacology analysis predicted that the drug monomers interacted with 54 disease targets. Based on clinical relevance analysis, six core targets were selected: VEGFA, IL2, CASP3, BCL2L1, MMP2, and MMP1. Molecular docking results showed binding activity between the Saikosaponin-d monomer and these core targets. Saikosaponin-d could inhibit gastric cancer cell proliferation, induce apoptosis, and inhibit cell migration and invasion.

Advances in the anti-tumor mechanisms of saikosaponin D

Saikosaponin D, a saponin compound, is extracted from Bupleurum and is a principal active component of the plant. It boasts a variety of pharmacologic effects including anti-inflammatory, antioxidant, immunomodulatory, metabolic, and anti-tumor properties, drawing significant attention in anti-tumor research in recent years. Research indicates that saikosaponin D inhibits the proliferation of numerous tumor cells, curbing the progression of cancers such as liver, pancreatic, lung, glioma, ovarian, thyroid, stomach, and breast cancer. Its anti-tumor mechanisms largely involve inhibiting tumor cell proliferation, promoting tumor cell apoptosis, thwarting tumor-cell invasion, and modulating tumor cell autophagy. Moreover, saikosaponin D enhances the sensitivity to anti-tumor drugs and augments body immunity. Given its multi-faceted anti-tumor roles, saikosaponin D offers promising potential in anti-tumor therapy. This paper reviews recent studies on its anti-tumor effects, aiming to furnish new theoretical insights for clinical cancer treatments.

Saikosaponin-d mediates FOXG1 to reverse docetaxel resistance in prostate cancer through oxidative phosphorylation

BACKGROUND

Prostate cancer (PCa), a prevalent malignancy worldwide, is frequently identified in advanced stages due to the absence of distinctive early symptoms, thereby culminating in the development of chemotherapy-induced drug resistance. Exploring novel resistance mechanisms and identifying new therapeutic agents can facilitate the advancement of more efficacious strategies for PCa treatment.

METHODS

Bioinformatics analysis was employed to investigate the expression of FOXG1 in PCa tissues. Subsequently, qRT-PCR was utilized to validate FOXG1 mRNA expression levels in corresponding PCa cell lines. FOXG1 knockdown was performed, and cell proliferation was assessed using CCK-8 assays, while cell migration and invasion capabilities were evaluated through wound healing and Transwell assays. Western blot and Seahorse analyzer were used to measure oxidative phosphorylation (OXPHOS) levels. Additionally, to explore potential approaches to alleviate PCa drug resistance, this study assessed the impact of biologically active saikosaponin-d (SSd) on PCa malignant progression and resistance by regulating FOXG1 expression.

RESULTS

FOXG1 exhibited high expression in PCa tissues and cell lines. Knockdown of FOXG1 inhibited the proliferation, migration, and invasion of PCa cells, while FOXG1 overexpression had the opposite effect and promoted OXPHOS levels. The addition of an OXPHOS inhibitor prevented this outcome. Finally, SSd was shown to suppress FOXG1 expression and reverse docetaxel resistance in PCa cells through the OXPHOS pathway.

CONCLUSION

This work demonstrated that SSd mediated FOXG1 to reverse malignant progression and docetaxel resistance in PCa through OXPHOS.

Diosbulbin C, a novel active ingredient in Dioscorea bulbifera L. extract, inhibits lung cancer cell proliferation by inducing G0/G1 phase cell cycle arrest

BACKGROUND

Despite the critical progress of non-small cell lung cancer (NSCLC) therapeutic approaches, the clinical outcomes remain considerably poor. The requirement of developing novel therapeutic interventions is still urgent. In this study, we showed for the first time that diosbulbin C, a natural diterpene lactone component extracted from traditional Chinese medicine Dioscorea bulbifera L., possesses high anticancer activity in NSCLC.

METHODS

A549 and NCI-H1299 cells were used. The inhibitory effects of the diosbulbin C on NSCLC cell proliferation were evaluated using cytotoxicity, clone formation, EdU assay, and flow cytometry. Network pharmacology methods were used to explore the targets through which the diosbulbin C inhibited NSCLC cell proliferation. Molecular docking, qRT-PCR, and western blotting were used to validate the molecular targets and regulated molecules of diosbulbin C in NSCLC.

RESULTS

Diosbulbin C treatment in NSCLC cells results in a remarkable reduction in cell proliferation and induces significant G0/G1 phase cell cycle arrest. AKT1, DHFR, and TYMS were identified as the potential targets of diosbulbin C. Diosbulbin C may inhibit NSCLC cell proliferation by downregulating the expression/activation of AKT, DHFR, and TYMS. In addition, diosbulbin C was predicted to exhibit high drug-likeness properties with good water solubility and intestinal absorption, highlighting its potential value in the discovery and development of anti-lung cancer drugs.

CONCLUSIONS

Diosbulbin C induces cell cycle arrest and inhibits the proliferation of NSCLC cells, possibly by downregulating the expression/activation of AKT, DHFR, and TYMS.

Saikosaponin D reverses epinephrine- and norepinephrine-induced gemcitabine resistance in intrahepatic cholangiocarcinoma by downregulating ADRB2/glycolysis signaling

Intrahepatic cholangiocarcinoma (iCCA) is a highly fatal malignancy with rapidly increasing incidence and mortality worldwide. Currently, gemcitabine-based systemic chemotherapy is the main clinical therapeutic regimen; however, its efficacy is poor, and its mechanism has not been elucidated. In this study, we use a Seahorse Extracellular Flux analyser to measure glycolysis capacity (extracellular acidification rate, ECAR) and oxygen consumption rate (OCR). The glucose uptake or lactic acid content is detected, and the effects of saikosaponin D, an active compound derived from Bupleuri Radix (a traditional Chinese medicine for soothing the liver and relieving depression), on gemcitabine cytotoxicity in norepinephrine-stimulated iCCA cells are analysed. We find that adrenergic signaling plays a fundamental role in chronic stress-induced therapeutic resistance in iCCA. Norepinephrine (NE) and epinephrine (E) enhance the proliferation of iCCA cells and interfere with the response to gemcitabine through activation of the β2-adrenergic receptor (ADRB2). Furthermore, we find that NE upregulates the expressions of several drug efflux-related genes (such as ABCG2 and MDR1) and promotes glycolysis in iCCA cells. In addition, saikosaponin D reverses the poor response of iCCA cells to gemcitabine by downregulating ADRB2 level. Furthermore, saikosaponin D inhibits drug efflux and glycolysis in iCCA cells by regulating the expressions of MDR1, ABCG2, HK2, and GLUT1. Collectively, saikosaponin D enhances the antitumor effect of gemcitabine by controlling glucose metabolism and drug efflux by inhibiting the ADRB2 signaling. Therefore, the combination of saikosaponin D and gemcitabine may be a potential therapeutic strategy for the treatment of iCCA.

A comprehensive review on traditional and modern research of the genus Bupleurum (Bupleurum L., Apiaceae) in recent 10 years

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Bupleurum (family Apiaceae), comprising approximately 248 accepted species, is widely distributed and used in China, Japan, India, Central Asia, North Africa and some European countries as traditional herbal medicines. Certain species have been reported to have significant therapeutic effects in fever, inflammatory disorders, cancer, gastric ulcer, virus infection and other diseases.

AIM OF THE REVIEW

we performed a comprehensive review of the ten-year research progress in phytochemistry, pharmacology, toxicity, along with bibliometrics research of the genus Bupleurum, aiming to identify knowledge gaps for future research.

MATERIALS AND METHODS

All the literatures are retrieved from library and electronic sources including Web of Science, PubMed, Elsevier, Google Scholar, CNKI and Baidu Scholar. These papers cover studies of the traditional use, phytochemistry, pharmacology, and toxicology of the genus Bupleurum.

RESULTS

There is a long history of using the genus Bupleurum in traditional herbal medicine that dated back to over 2000 years ago. Twenty-five species and 8 varieties with 3 variants within this genus have been reported to be effective to treat fever, pain, liver disease, inflammation, thoracolumbar pain, irregular menstruation and rectal prolapse. The main phytochemicals found in these plants are triterpene saponins, volatile oil, flavonoid, lignans, and polysaccharides. Many of these compounds have also been shown to have anti-inflammatory, anti-tumor, antimicrobial, immunoregulation, neuroregulation, hepatoprotective and antidiabetic activities. Meanwhile, improper usage of Bupleurum may induce cytotoxic effects, and polyacetylenes may be the main poisonous compounds.

CONCLUSIONS

This article summarized recent findings about Bupleurum research from many different aspects. While a small number of Bupleurum species have been investigated through modern pharmacology methods, there are still major knowledge gaps due to inadequate studies and ambiguous findings. Future research could focus on more specific phytochemistry studies combined with mechanistic analysis to provide better guidance to utilize Bupleurum as medicinal resources.

Targeting ER Stress with Saikosaponin A to Overcome Resistance under Radiation in Gastric Cancer Cells

Saikosaponin A is a triterpene saponin and a potentially bioactive compound derived from Bupleurum falcatum L. However, the molecular mechanisms and effects of saikosaponin A in gastric cancer remain unknown. In the present study, I evaluated the effects of saikosaponin A on cell death and endoplasmic reticulum stress via calcium and reactive oxygen species release. Targeting reactive oxygen species with diphenyleneiodonium and N-acetylcysteine inhibited cell death and protein kinase RNA-like ER kinase signaling pathway by down-regulating Nox4 and inducing glucose-regulated protein 78 exosomes. Furthermore, saikosaponin A caused a synergistic inhibitory effect of the epithelial mesenchymal transition phenomenon, indicating the reversible phenotype modulation by epithelial cells under radiation exposure in radiation-resistant gastric cancer cells. These results suggest that saikosaponin A-mediated calcium and reactive oxygen species-induced endoplasmic reticulum stress overcome radio-resistance and induce cell death under radiation in gastric cancer cells. Therefore, saikosaponin A in combination with radiation may be a potential strategy for gastric cancer therapy.

Combined treatment with Prunella vulgaris and Radix bupleuri activated the Bax/Bcl-2 and Caspase-3 signal pathways in papillary thyroid carcinoma cells

To explore the effect of Prunella vulgaris (PV) combined with Radix bupleuri (RB) on apoptosis of papillary thyroid carcinoma cells. Our study was divided into four groups: the control group, the PV group, the RB group, and the PV combined with the RB group. The viability of cells from different treatment groups was assessed by the CCK-8 assay. Cell migration and invasion were assessed by healing wounding and the transwell assay, respectively. Cell apoptosis rate and cell cycle arrest were detected by a flow cytometry assay. The protein expression of Bcl-2, Bax, Caspase-3, CyclinA1, CyclinB1, and CDK1 was detected using a western blot assay. Our results indicated that, compared with the control group, PV combined with RB group could significantly alter the cell morphology, inhibit cell migration and invasion, decrease the number of cells in the G0/G1 phase and increase the number of cells in the G2/M phase, and promote the cell apoptosis. Moreover, PV combined with RB treatment also obviously increased the expression of Bax/Bcl2 and caspase-3 proteins and decreased the expression of Cyclin A1, Cyclin B1, and CDK1 proteins. Overall, our results indicated that PV combined with RB could activate the Bax/Bcl-2 and Caspase-3 signal pathways to induce cell apoptosis in papillary thyroid carcinoma cells; this also provides a new way to treat thyroid cancer.

Chemotherapeutic Potential of Saikosaponin D: Experimental Evidence

Saikosaponin D (SSD), an active compound derived from the traditional plant Radix bupleuri, showcases potential in disease management owing to its antioxidant, antipyretic, and anti-inflammatory properties. The toxicological effects of SSD mainly include hepatotoxicity, neurotoxicity, hemolysis, and cardiotoxicity. SSD exhibits antitumor effects on multiple targets and has been witnessed in diverse cancer types by articulating various cell signaling pathways. As a result, carcinogenic processes such as proliferation, invasion, metastasis, and angiogenesis are inhibited, whereas apoptosis, autophagy, and differentiation are induced in several cancer cells. Since it reduces side effects and strengthens anti-cancerous benefits, SSD has been shown to have an additive or synergistic impact with chemo-preventive medicines. Regardless of its efficacy and benefits, the considerations of SSD in cancer prevention are absolutely under-researched due to its penurious bioavailability. Diverse studies have overcome the impediments of inadequate bioavailability using nanotechnology-based methods such as nanoparticle encapsulation, liposomes, and several other formulations. In this review, we emphasize the association of SSD in cancer therapeutics and the discussion of the mechanisms of action with the significance of experimental evidence.

Saikosaponin D improves chemosensitivity of glioblastoma by reducing the its stemness maintenance

Objective

Chemotherapy is one of the important adjuvant methods for the treatment of glioblastoma (GBM), and chemotherapy resistance is a clinical problem that neurooncologists need to solve urgently. It is reported that Saikosaponin D (SSD), an active component of Bupleurum chinense, had various of antitumor activities and could also enhance the chemosensitivity of liver cancer and other tumors. However, it is not clear whether it has an effect on the chemosensitivity of glioma and its specific mechanism.

Methods

The CCK8 assay, Wound healing assay and Matrigel invasion assay were used to detect the effect of SSD on the phenotype of GBM cells. We detected the effect of SSD on the chemosensitivity of GSM by Flow cytometry, LDH content and MTT assay. Then, we used cell plate cloning, semi-quantitative PCR and western blotting experiments to detect the effect of SSD on the stem potential of GBM cells. Finally, the effect of SSD on the chemosensitivity of GBM and its potential mechanism were verified by nude mouse experiments in vivo.

Results

firstly, we found that SSD could partially inhibit the malignant phenotype of LN-229 cells, including inhibiting migration, invasion and apoptosis, and increasing the apoptosis rate and lactate dehydrogenase (LDH) release of LN-229 cells under the treatment of temozolomide (TMZ), that is to say, increasing the chemotherapy effect of TMZ on the cells. In addition, we unexpectedly found that SSD could partially inhibit the colony forming ability of LN-229 cells, which directly related to the stemness maintenance potential of cancer stem cells. Subsequently, our results showed that SSD could inhibit the gene and protein expression of stemness factors (OCT4, SOX2, c-Myc and Klf4) in LN-229 cells. Finally, we verified that SSD could improve the chemotherapy effect of TMZ by inhibiting the stem potential of glioblastoma in vivo nude mice.

Conclusion

this research can provide a certain theoretical basis for the application of SSD in the chemotherapy resistance of GBM and its mechanism of action, and provide a new hope for the clinical treatment of glioblastoma.

•

SSD could inhibit the malignant phenotype of LN-229 cells, increase the chemotherapy effect of TMZ on the cells.

•

SSD could inhibit the colony forming ability of LN-229 cells, and also inhibit their gene and protein expression of stemness factors.

•

We verified that SSD could improve the chemotherapy effect of TMZ by inhibiting the stem potential of glioblastoma.

Saikosaponins: A Review of Structures and Pharmacological Activities

Radix Bupleuri is a traditional medicine widely used in China and other Asian countries. Phytochemistry and pharmacology study reveal that saikosaponins(SSs) are the main bioactive compounds in Radix Bupleuri. SSs are complex compounds composed of triterpene aglycone and carbohydrate part containing 1-13 monosaccharides, which can be divided into seven types based on their structural characteristics. Many different kinds of SSs have been isolated from plants of Bupleurum L. SSs show a variety of biological activities, such as central nervous system protection, liver protection, antivirus, anti-tumor, anti-inflammation, hormone-like effects, and immune regulation functions. Due to their broad activity and favorable safety profile, SSs attract an increasing amount of attention in recent years. In this review, the structures of 86 SSs are summarized based on the different aglycones due to the diverse structures of saikosaponin(SS). The pharmacological effects and related mechanism of SSs are thoroughly reviewed, and perspectives for future research are further discussed.

Saikosaponin D: review on the antitumour effects, toxicity and pharmacokinetics

CONTEXT

Bupleuri Radix, the dried root of Bupleurum chinense DC and Bupleurum scorzonerifolium Willd (Apiaceae), is an important medicinal herb widely used to treat cancers for hundreds of years in Asian countries. As the most antitumour component but also the main toxic component in Bupleuri Radix, saikosaponin D (SSD) has attracted extensive attention. However, no summary studies have been reported on the antitumour effects, toxicity and pharmacokinetics of this potential natural anticancer substance.

OBJECTIVE

To analyse and summarise the existing findings regarding to the antitumour effects, toxicity and pharmacokinetics of SSD.

MATERIALS AND METHODS

We collected relevant information published before April 2021 by conducting a search of literature available in various online databases including PubMed, Science Direct, CNKI, Wanfang database and the Chinese Biological Medicine Database. Bupleurum, Bupleuri Radix, saikosaponin, saikosaponin D, tumour, toxicity, and pharmacokinetics were used as the keywords.

RESULTS

The antitumour effects of SSD were multi-targeted and can be realised through various mechanisms, including inhibition of proliferation, invasion, metastasis and angiogenesis, as well as induction of cell apoptosis, autophagy, and differentiation. The toxicological effects of SSD mainly included hepatotoxicity, neurotoxicity, haemolysis and cardiotoxicity. Pharmacokinetic studies demonstrated that SSD had the potential to alter the pharmacokinetics of some drugs for its influence on CYPs and P-gp, and the oral bioavailability and actual pharmacodynamic substances in vivo of SSD are still controversial.

CONCLUSIONS

SSD is a potentially effective and relatively safe natural antitumour substance, but more research is needed, especially in vivo antitumour effects and pharmacokinetics of the compound.

Upregulation of miR-886 indicates poor prognosis and promotes tumour progression of prostate cancer

Prostate cancer is a heterogeneous disease with high incidence and mortality. The functional role of miR-886 has been reported in various cancers and its dysregulation in prostate cancer was also found. Whether miR-886 was involved in the development of prostate cancer remains unclear, which was explored. miR-886 was evaluated in prostate cancer by RT-qPCR, and its clinical value was also assessed. Additionally, the role of miR-886 in prostate cancer cells was assessed by MTT and transwell assay. miR-886 was upregulated and was associated with the Gleason score and TNM stage of prostate cancer patients. miR-886 could predict the poor survival of patients. Moreover, miR-886 was a tumour promoter, of which the upregulation significantly promoted major cellular processes of prostate cancer. miR-886 mediated the disease development and predicted the clinical outcomes of patients. The knockdown of miR-886 inhibits cellular processes of prostate cancer, which provides a novel therapeutic target.

Plant-Derived Saponins: A Review of Their Surfactant Properties and Applications

In response to increasing natural surfactant demand and environmental concerns, natural plant-based surfactants have been replacing synthetic ones. Saponins belong to a class of plant metabolites with surfactant properties that are widely distributed in nature. They are eco-friendly because of their natural origin and biodegradable. To date, many plant-based saponins have been investigated for their surface activity. An overview of saponins with a particular focus on their surface-active properties is presented in this article. For this purpose, works published in the past few decades, which report better surfactant relevant properties of saponins than synthetic ones, were extensively studied. The investigations on the potential surfactant application of saponins are also documented. Moreover, some biological activities of saponins such as antimicrobial activity, antidiabetic activity, adjuvant potentials, anticancer activity, and others are reported. Plants rich in saponins are widely distributed in nature, offering great potential for the replacement of toxic synthetic surfactants in a variety of modern commercial products and these saponins exhibit excellent surface and biological activities. New opportunities and challenges associated with the development of saponin-based commercial formulations in the future are also discussed in detail.

Saikosaponin D Inhibits the Proliferation and Promotes the Apoptosis of Rat Hepatic Stellate Cells by Inducing Autophagosome Formation

Objective

This study aimed to investigate the effects of saikosaponin D (SSd) on the proliferation and apoptosis of the HSC-T6 hepatic stellate cell line and determine the key pathway that mediates SSd's function.

Methods

Cell viability was detected using the CCK-8 kit. The EdU kit and flow cytometry were used to examine cell proliferation. The Annexin V-FITC/PI double staining kit and flow cytometry were used to examine cell apoptosis. Western blot analysis was performed to analyze the expression levels of LC3, Ki67, cleaved caspase 3, Bax, and Bcl2. Autophagosome formation was detected by LC3-GFP adenovirus transfection.

Results

SSd inhibits the proliferation and promotes the apoptosis of acetaldehyde-activated HSC-T6 cells. SSd treatment increased the expression of cleaved caspase 3 and Bax but reduced that of Ki67 and Bcl2. The same concentration of SSd barely influenced the growth of normal rat liver BRL-3A cells. SSd upregulated LC3-II expression and induced autophagosome formation. Autophagy agonist rapamycin had the same effect as SSd and autophagy inhibitor 3-methyladenine could neutralize the effect of SSd in acetaldehyde-activated HSC-T6 cells.

Conclusions

SSd could inhibit the proliferation and promote the apoptosis of HSC-T6 cells by inducing autophagosome formation.

Active components of Bupleurum chinense and Angelica biserrata showed analgesic effects in formalin induced pain by acting on Nav1.7

ETHNOPHARMACOLOGY RELEVANCE

Pain is an unpleasant sensory and emotional experience, often accompanied by the occurrence of a variety of diseases. More than 800 kinds of traditional Chinese medicines (TCM) has now been reported for pain relief and several monomers have been developed into novel analgesic drugs. Bupleurum chinense and Angelica biserrata were representatives of the TCM that are currently available for the treatment of pain.

AIM OF THE STUDY

The study aims to detect the potential analgesic activity of each monomer of Bupleurum chinense and Angelica biserrata and to explore whether Nav1.7 is one of the targets for its analgesic activity.

MATERIALS AND METHODS

In this study, five monomers from Bupleurum chinense (Saikosaponin A, Saikosaponin B1, Saikosaponin B2, Saikosaponin C, Saikosaponin D) and five monomers from the Angelica biserrata (Osthole, Xanthotoxin, Imperatorin, Isoimperatorin, Psoralen) were examined by whole-cell patch-clamp on Nav1.7, which was closely associated with pain. Classical mouse pain models were also used to further verify the analgesic activity in vivo.

RESULTS

The results showed that monomers of Saikosaponins and Angelica biserrata all inhibited the peak currents of Nav1.7, indicating that Nav1.7 might be involved in the analgesic mechanism of Saikosaponins and Angelica biserrata. Among them, Saikosaponin A and Imperatorin showed the strongest inhibitory effect on Nav1.7. Furthermore, both Saikosaponin A and Imperatorin showed inhibitory effects on thermal pain and formalin-induced pain in phase II in vivo.

CONCLUSION

The results provide valuable information for future studies on the potential of TCM in alleviating pain.

A Diamine-PEGylated Oleanolic Acid Derivative Induced Efficient Apoptosis through a Death Receptor and Mitochondrial Apoptotic Pathway in HepG2 Human Hepatoma Cells

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Our recent studies have shown that the diamine-(PEG)ylated oleanolic acid (OADP) has strong anti-tumor effects in HCCs. In this study, we evaluated the anti-tumor mechanisms of OADP in the HepG2 HCC cell line. The cytotoxicity results showed that HepG2 cell viability was markedly reduced, with a very low 50% of cell growth inhibitory concentration (IC₅₀, 0.14 µg/mL). We then investigated the anti-tumor mechanisms of OADP in HepG2 cells. The flow-cytometry analysis was used to evaluate cell apoptosis, indicating that 74–95% of cells were apoptotic. OADP caused cell cycle arrest in the G0/G1 phase and the loss of the mitochondrial membrane potential (MMP). Western blot analysis was performed to assess the expression levels of key proteins associated with the underlying molecular mechanism. The results showed the clear upregulation of caspase-8, caspase-9, caspase-3, Bak, p21, and p53, accompanied by the downregulation of Bcl-2. Similar results were obtained by the cotreatment with OADP and the c-Jun N-terminal kinase (JNK) inhibitor SP600125. Agents such as OADP, which are capable of activating extrinsic and intrinsic apoptotic pathways, may represent potential HCC cancer therapies.

Saikosaponin D inhibits proliferation and induces apoptosis of non-small cell lung cancer cells by inhibiting the STAT3 pathway

OBJECTIVE

To study the effects of saikosaponin D (SSD) on proliferation and apoptosis in human non-small cell lung cancer cell lines, and to explore underlying mechanisms.

METHODS

Following treatment with saikosaponin D, A549 and H1299 cells were assessed for anti-proliferation effects using cell cycle kit-8 assays, changes in nuclear morphology using 4',6-diamidino-2-phenylindole (DAPI) staining, and cell apoptosis using annexin V/propidium iodide double staining. Proliferation- and apoptosis-related proteins were detected by immunoblotting.

RESULTS

Saikosaponin D had dose-dependent inhibitory effects on A549 cells (IC₅₀, 3.57 µM) and H1299 cells (IC₅₀, 8.46 µM). DAPI staining revealed decreased cell numbers, and most H1299 cells became round after treatment with 20 µM saikosaponin D. As saikosaponin D concentration increased, the proportions of cells in G0/G1 phase, and cells undergoing apoptosis, increased. Levels of phosphorylated p44/42 and signal transducer and activator of transcription (STAT)3 were significantly downregulated in both cell lines, while total STAT3 levels were not significantly affected. The cleaved form of caspase 3 was significantly upregulated.

CONCLUSIONS

Saikosaponin D inhibits proliferation, inducing cell cycle arrest and apoptosis, in lung cancer cells in a dose-dependent manner, possibly through inhibition of STAT3 phosphorylation and activation of caspase 3.

The Effects and Mechanisms by which Saikosaponin-D Enhances the Sensitivity of Human Non-small Cell Lung Cancer Cells to Gefitinib

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR)-sensitive mutations benefit from epidermal growth factor receptor tyrosine kinase inhibitors (EGFR- TKIs). However, drug resistance is a major cause of therapeutic failure. This study examined whether saikosaponin-d (SSD) enhances the anti-tumor effect of gefitinib in NSCLC cells. Cell Counting Kit-8 (CCK-8) was used to determine cell viability. Cell apoptosis was examined by flow cytometry. Signal transducer and activator of transcription (STAT3), phosphor-STAT3 (P-STAT3), and B-cell lymphoma 2 (Bcl-2) were detected by Western blot. An HCC827/GR tumor model was established to observe the effect of combination therapy in vivo. The combination of SSD with gefitinib had an enhanced inhibitory effect by reducing cell viability and inducing cells apoptosis in NSCLC cells. Furthermore, SSD decreased and increased the expression of P-STAT3 and Bcl-2, respectively. Down-regulated STAT3 promoted the sensitivity of lung cancer cells to gefitinib. The results of animal experiments also showed that SSD enhanced the anti-tumor effect of gefitinib. These results indicated that the combination of SSD with gefitinib had an increased antitumor effect in NSCLC cells and that the molecular mechanisms were associated with the inhibition of STAT3/Bcl-2 signaling pathway. Our findings suggest a promising approach for the treatment of NSCLC patients with EGFR-TKI resistance.

Saikosaponin-d Suppresses COX2 Through p-STAT3/C/EBPβ Signaling Pathway in Liver Cancer: A Novel Mechanism of Action

Saikosaponin-d (SSd) is an active extract from Radix Bupleuri, the dried root from the plant Bupleurum falcatum used in China for thousands of years to treat liver diseases. The SSd extract possesses valuable pharmacological activities including anti-cancer and anti-inflammatory effects; however, the mechanism underlying the anti-cancer activity of SSd is largely unknown. Here, we explored the mechanism of action of SSd as an anti-cancer agent for liver cancer in two human hepatocellular carcinoma cell lines. Using MTT and annexin-V-FITC/PI assays, Western blots, immunohistochemistry, qRT-PCR, luciferase reporter assay, and a JAK2-specific inhibitor (AG490), we demonstrated that the anti-tumorigenic effects of SSd act through the intermediatory p-STAT3/C/EBPβ signaling pathway to suppress cyclooxygenase (COX)-2. SSd effectively inhibited cell proliferation in a dose-dependent manner. Apoptosis was significantly increased in cells treated with SSd (2.5–15 µg/ml) with concurrent increase and decrease in pro- and anti-apoptosis proteins, respectively. COX-2, C/EBPβ, and p-STAT3 were significantly decreased, at both the translational and transcriptional levels, by SSd treatment. AG490 produced similar inhibitory effects on STAT3, p-STAT3, C/EBPβ, and COX-2. In conclusion, our data suggest that SSd controls liver cancer proliferation through suppression of the p-STAT3/C/EBPβ signaling pathway inhibiting COX2 expression. These findings further our understanding of the pharmacological action of SSd, providing new information on SSd mechanism of action and showing potential for SSd as a novel therapy for liver cancer.

Saikosaponin d causes apoptotic death of cultured neocortical neurons by increasing membrane permeability and elevating intracellular Ca2+ concentration

Saikosaponins (SSs) are a class of naturally occurring oleanane-type triterpenoid saponins found in Radix bupleuri that has been widely used in traditional Chinese medicine. As the main active principals of Radix bupleuri, SSs have been shown to suppress mouse motor activity, impair learning and memory, and decrease hippocampal neurogenesis. In the present study, we investigated the effect of five SSs (SSa, SSb1, SSb2, SSc, and SSd) on neuronal viability and the underlying mechanisms in cultured murine neocortical neurons. We demonstrate that SSa, SSb1 and SSd produce concentration-dependent apoptotic neuronal death and induce robust increase in intracellular Ca²⁺ concentration ([Ca²⁺]_i) at low micromolar concentrations with a rank order of SSd > SSa > SSb1, whereas SSb2 and SSc have no detectable effect on both neuronal survival and [Ca²⁺]_i. Mechanistically, SSd-induced elevation in [Ca²⁺]_i is the primary result of enhanced extracellular Ca²⁺ influx, which likely triggers Ca²⁺-induced Ca²⁺ release through ryanodine receptor activation, but not SERCA inhibition. SSd-induced Ca²⁺ entry occurs through a non-selective mechanism since blockers of major neuronal Ca²⁺ entry pathways, including L-type Ca²⁺ channel, NMDA receptor, AMPA receptor, Na⁺-Ca²⁺ exchanger, and TRPV1, all failed to attenuate the Ca²⁺ response to SSd. Further studies demonstrate that SSd increases calcein efflux and induces an inward current in neocortical neurons. Together, these data demonstrate that SSd elevates [Ca²⁺]_i due to its ability to increase membrane permeability, likely by forming pores in the surface of membrane, which leads to massive Ca²⁺ influx and apoptotic neuronal death in neocortical neurons.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

The Role of Saikosaponins in Therapeutic Strategies for Age-Related Diseases

As life expectancy increases, elderly populations tend to spend an increasing number of years in poor health, with chronic age-related diseases and disability. Therefore, the development of therapeutic strategies to treat or prevent multiple pathophysiological conditions in the elderly may improve health-adjusted life expectancy and alleviate the potential economic and social burdens arising from age-related diseases. Bioactive natural products might represent promising new drug candidates for the treatment of many chronic age-related diseases, including cancer, Alzheimer's disease, cardiovascular disease, obesity, and liver disease. Here, we discuss a therapeutic option using saikosaponins, which are triterpene saponins isolated from Bupleurum, against a variety of age-related diseases. Understanding the underlying mechanisms of natural products like saikosaponins in the treatment of age-related diseases may help in the development of diverse natural product-derived compounds that may be effective against a number of chronic health problems.

Saikosaponin‑d alleviates carbon‑tetrachloride induced acute hepatocellular injury by inhibiting oxidative stress and NLRP3 inflammasome activation in the HL‑7702 cell line

Saikosaponin‑d (SSd) the primary active component of triterpene saponin derived from Bupleurum falcatum L., possesses anti‑inflammatory and antioxidant properties. The present study aimed to examine the potential therapeutic effects of SSd on carbon tetrachloride (CCl4)‑induced acute hepatocellular injury in the HL‑7702 cell line and its underlying mechanisms. HL‑7702 cells were treated with SSd at different doses (0.5, 1 or 2 µmol/l). Cell viability was determined using an MTT assay. Injury was assessed by the levels of serum alanine aminotransferase (ALT) and aspartate transaminase (AST). Oxidative stress was assessed using malondialdehyde (MDA) content and total‑superoxide dismutase (T‑SOD) activity. The expression of nucleotide‑binding domain, leucine‑rich‑containing family, pyrin domain‑containing‑3 (NLRP3), apoptosis‑associated speck‑like protein (ASC), caspase‑1 and high mobility group protein B1 (HMGB1) was assessed by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. Interleukin (IL)‑1β and IL‑18 were determined by RT‑qPCR and ELISA. SSd attenuated the inhibition of cell viability and the high AST and ALT levels induced by CCl4 in HL‑7702 cells. Oxidative stress was induced in HL‑7702 cells by CCl4, as demonstrated by the increase of MDA and the decrease of T‑SOD activity. These changes were reversed by SSd. SSd significantly downregulated the mRNA and protein expression of NLRP3, ASC, caspase‑1, IL‑1β, IL‑18 and HMGB1 induced by CCl4. In conclusion SSd alleviated CCl4‑induced acute hepatocellular injury, possibly by inhibiting oxidative stress and NLRP3 inflammasome activation in the HL‑7702 cell line.

A systematic review of the active saikosaponins and extracts isolated from Radix Bupleuri and their applications

CONTEXT

Radix Bupleuri has been used in traditional Chinese medicine for over 2000 years with functions of relieving exterior syndrome, clearing heat, regulating liver-qi, and lifting yang-qi. More natural active compounds, especially saikosaponins, have been isolated from Radix Bupleuri, which possess various valuable pharmacological activities.

OBJECTIVE

To summarize the current knowledge on pharmacological activities, mechanisms and applications of extracts and saikosaponins isolated from Radix Bupleuri, and obtain new insights for further research and development of Radix Bupleuri.

METHODS

PubMed, Web of Science, Science Direct, Research Gate, Academic Journals and Google Scholar were used as information sources through the inclusion of the search terms 'Radix Bupleuri', 'Bupleurum', 'saikosaponins', 'Radix Bupleuri preparation', and their combinations, mainly from the year 2008 to 2016 without language restriction. Clinical preparations containing Radix Bupleuri were collected from official website of China Food and Drug Administration (CFDA).

RESULTS AND CONCLUSION

296 papers were searched and 128 papers were reviewed. A broad spectrum of in vitro and in vivo research has proved that Radix Bupleuri extracts, saikosaponin a, saikosaponin d, saikosaponin c, and saikosaponin b₂, exhibit evident anti-inflammatory, antitumor, antiviral, anti-allergic, immunoregulation, and neuroregulation activities mainly through NF-κB, MAPK or other pathways. 15 clinical preparations approved by CFDA remarkably broaden the application of Radix Bupleuri. The main side effect of Radix Bupleuri is liver damage when the dosage is excess, which indicates that the maximum tolerated dose is critical for clinical use of Radix Bupleuri extract and purified compounds.

Saikosaponin-d, a calcium mobilizing agent, sensitizes chemoresistant ovarian cancer cells to cisplatin-induced apoptosis by facilitating mitochondrial fission and G2/M arrest

Cisplatin (CDDP) and its derivatives are first line anti-cancer drugs for ovarian cancer (OVCA). However, chemoresistance due to high incidence of p53 mutations leads to poor clinical prognosis. Saikosaponin-d (Ssd), a saponin from a herbal plant extract, has been shown to induce cell death and sensitize chemoresistant cells to chemotherapeutic agents. Here, we demonstrated that Ssd sensitized chemoresistant OVCA cells with either p53-wt, -mutant and -null to CDDP. The action of Ssd appears to be through induction of mitochondrial fragmentation and G2/M arrest. Ssd is mediated via calcium signaling, up-regulation of the mitochondrial fission proteins Dynamin-related protein 1 (Drp1) and optic atrophy 1 (Opa1), and loss in mitochondrial membrane potential (MMP). Moreover, in the presence of CDDP, Ssd also down-regulates protein phosphatase magnesium-dependent 1 D (PPM1D) and increases the phosphorylation of checkpoint protein kinases (Chk) 1, cell division cycle 25c (Cdc25c) and Cyclin dependent kinase 1 (Cdk1). Our findings suggest that Ssd could sensitize OVCA to CDDP independent of the p53 status through multiple signaling pathways. They support the notion that Ssd may be a novel adjuvant for the treatment of chemoresistant OVCA.

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.

Complementary traditional Chinese medicine therapy improves survival in patients with metastatic prostate cancer

More than 50% of prostate cancer patients have used traditional Chinese medicine (TCM) in Taiwan. However, the long-term clinical efficacy of TCM in prostate cancer patients remains unclear. Here, we investigated the relationship between TCM use and the survival of prostate cancer patients.A retrospective nationwide cohort study of prostate cancer patients was conducted between 1998 and 2003 using the Taiwan National Health Insurance Research Database. Patients were classified as TCM users or nonusers, and monitored from the day of prostate cancer diagnosis to death or end of 2012. The association between death risk and TCM use was determined using Cox proportional-hazards models and Kaplan-Meier curves.Of the 1132 selected prostate cancer patients, 730 (64.5%) and 402 (35.5%) were TCM users and nonusers, respectively. The mean follow-up period was 8.38 years, and 292 (25.8%) deaths were reported. TCM users had a decreased mortality rate (21.9%) compared with nonusers (32.8%). A lower death risk was observed with longer TCM use, especially in patients who used TCM for ≧200 days (adjusted hazard ratio [aHR] 0.61, 95% confidence interval [CI] 0.44-0.84). TCM users with metastatic prostate cancer had a significant lower HR than nonusers (aHR 0.70, 95% CI 0.51-0.95). Chai-Hu-Jia-Long-Gu-Mu-Li-Tang was the most significant TCM formulae for improving survival in metastatic prostate cancer (aHR 0.18, 95% CI 0.04-0.94).The result suggested that complementary TCM therapy might be associated with a reduced risk of death in metastatic prostate cancer patients.

Saikosaponin-d: A potential chemotherapeutics in castration resistant prostate cancer by suppressing cancer metastases and cancer stem cell phenotypes

Androgen deprivation therapy is the gold standard regimen for advanced Prostate cancer (PCa) patients, nevertheless, patients eventually develop into castration-resistant prostate cancer (CRPC). Currently only a few chemotherapeutics are available for CRPC. Therefore, it is critical for identifying a new drug. In this study, we will explore a new agent, Saikosaponin-d (SSd), for CRPC therapy based on its mechanism of action. DU145 and CWR22Rv1 cells representing CRPC were employed in this study. A series of cell, biochemical, and molecular biologic assays such as Immunofluorescence, Zymography, Sphere formation, Colony formation, and MTT were used. Finally, we find SSd can significantly inhibit the growth of PCa cells in both dose- and time-dependent and suppress the colony formation during a long-term drug administration, it also can inhibit their migration and invasion abilities, which was accompanied by reverse the epithelial-mesenchymal transition (EMT) and suppress MMP2/9 expression as well as activities. Furthermore, SSd can suppress cancer stem cell (CSC) phenotypes such as self-renewal ability. Mechanistically, SSd blocks Wnt/β-catenin signaling pathway by decreasing GSK3β phosphorylation to affect EMT and CSC. These findings demonstrate the mechanism of anti-cancer activity of SSd in targeting EMT and CSC, suggesting SSd can be a potent agent for CRPC therapy.

Anti-melanoma activity of Bupleurum chinense, Bupleurum kaoi and nanoparticle formulation of their major bioactive compound saikosaponin-d

ETHNOPHARMACOLOGICAL RELEVANCE

Bupleurum chinense is a traditional Chinese medicinal herb which has been used to treat various inflammatory and infectious diseases, while Bupleurum kaoi is an endemic plant in Taiwan. We determined whether B. chinense and B. kaoi and their biologically active saikosaponin compounds possess anti-melanoma activity. In addition, we developed a novel saikosaponin-d nanoparticle system to improve its solubility, and evaluated its antiproliferative effects and molecular mechanisms in melanoma cells.

MATERIALS AND METHODS

Ethanolic extracts from B. chinense and B. kaoi were prepared, and their saikosaponin contents were determined by high performance liquid chromatography analysis. Saikosaponin-d nanoparticles were synthesized, and their physicochemical properties were evaluated by particle size analyzer, transmission electron microscopy, differential scanning calorimetry, X-ray diffractometry, and Fourier transform infrared spectroscopy. Human A375.S2 melanoma cells were cultured, and cell viability determined by the MTT assay. Apoptosis was evaluated by determination of mitochondrial membrane potential, and signal transduction pathways investigated by Western blotting.

RESULTS

Ethanolic extracts from B. kaoi showed more potent antiproliferative effect on human A375.S2 melanoma cells compared to B. chinense. The saikosaponin-a, -c and -d contents were higher in B. kaoi compared to B. chinense. Saikosaponin-d was the most potent compound in terms of anti-melanoma activity, and saikosaponin-d nanoparticles exhibited increased water solubility due to lowered particle size, amorphous transformation and intermolecular hydrogen bond formation with the excipient. Furthermore, saikosaponin-d nanoparticles showed enhanced antiproliferative activity against melanoma cells, and induced apoptosis through the mitochondrial pathway. The anti-melanoma activity was mediated by phosphorylation of JNK and p38, phosphorylation of p53, increased level of cytochrome c, and activation of caspase 9.

CONCLUSIONS

B. kaoi contains higher saikosaponin content and shows greater anti-melanoma activity than B. chinense. Saikosaponin-d nanoparticles have improved solubility, and may have potential use in the future as a form of treatment for melanoma.