Saikosaponin A, an active glycoside from Radix bupleuri, reverses P-glycoprotein-mediated multidrug resistance in MCF-7/ADR cells and HepG2/ADM cells

Pharmacology, medical uses, and clinical translational challenges of Saikosaponin A: A review

Saikosaponin A (SSA), the primary active monomer derived from the Radix bupleuri, demonstrates a diverse array of pharmacological activities, including anti-inflammatory, antitumor, analgesic, anti-fibrotic, antidepressant, and immune-modulating properties. Despite its potential therapeutic impact on various human diseases, comprehensive studies exploring SSA's efficacy in these contexts remain limited. This review synthesizes the current research landscape regarding SSA's therapeutic applications across different diseases, highlighting critical insights to overcome existing limitations and clinical challenges. The findings underscore the importance of further investigations into SSA's mechanisms of action, facilitating the development of targeted therapeutic strategies and their translation into clinical practice.

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.

Strategies to enhance the response of liver cancer to pharmacological treatments

In contrast to other types of cancers, there is no available efficient pharmacological treatment to improve the outcomes of patients suffering from major primary liver cancers, i.e., hepatocellular carcinoma and cholangiocarcinoma. This dismal situation is partly due to the existence in these tumors of many different and synergistic mechanisms of resistance, accounting for the lack of response of these patients, not only to classical chemotherapy but also to more modern pharmacological agents based on the inhibition of tyrosine kinase receptors (TKIs) and the stimulation of the immune response against the tumor using immune checkpoint inhibitors (ICIs). This review summarizes the efforts to develop strategies to overcome this severe limitation, including searching for novel drugs derived from synthetic, semisynthetic, or natural products with vectorial properties against therapeutic targets to increase drug uptake or reduce drug export from cancer cells. Besides, immunotherapy is a promising line of research that is already starting to be implemented in clinical practice. Although less successful than in other cancers, the foreseen future for this strategy in treating liver cancers is considerable. Similarly, the pharmacological inhibition of epigenetic targets is highly promising. Many novel "epidrugs," able to act on "writer," "reader," and "eraser" epigenetic players, are currently being evaluated in preclinical and clinical studies. Finally, gene therapy is a broad field of research in the fight against liver cancer chemoresistance, based on the impressive advances recently achieved in gene manipulation. In sum, although the present is still dismal, there is reason for hope in the non-too-distant future.

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.

Functional Doxorubicin-Loaded Omega-3 Unsaturated Fatty Acids Nanoparticles in Reversing Hepatocellular Carcinoma Multidrug Resistance

Background

This study investigated a nanoparticle drug delivery system to reverse multidrug resistance (MDR) and assessed its anticancer efficacy in hepatocellular carcinoma (HCC).

Material/Methods

Docosahexaenoic acid (DHA) was used as the functional excipient and doxorubicin (DOX) as the chemotherapeutic drug to synthesize DOX nanoparticles (DOX-nano). The human HCC cell line HepG2 was used for experiments. HepG2/DOX, HepG2+DOX, HepG2+DOX-nano, HepG2/DOX+DOX, and HepG2/DOX+DOX-nano groups cells were treated with DOX or DOX-nano (5 μg/mL). Nude mice bearing a HepG2/DOX xenograft were divided into model, DOX, vector-nano, and DOX-nano groups and injected with saline, DOX reagent, vector-nano, and DOX-nano (2 mg/kg), respectively. Next, cytotoxicity, cellular uptake, cell apoptosis and migration, fluorescence imaging, TUNEL assay, and tumor inhibition effects were assessed in vitro and in vivo. Furthermore, expression of MDR-related proteins was also detected using western blotting.

Results

Fluorescence imaging showed that the DOX uptake in the DOX-nano-treated group was the strongest in the HCC cells or tumors. Cell apoptosis was significantly increased in DOX-nano-treated HepG2/DOX cells and tumors, and cell migration was significantly inhibited in the DOX-nano-treated HepG2/DOX cells compared with the other groups. The tumor inhibitory rate in DOX-nano-injected tumors was also significantly higher than in other groups. The expression of breast cancer resistance protein, B-cell lymphoma 2, lung resistance protein, multidrug resistance protein, and protein kinase C alpha was significantly decreased in DOX-nano-treated HepG2/DOX cells and xenograft tumors. Significantly better antitumor and MDR-reversing effects were also observed in the HepG2+DOX group compared with the HepG2/DOX group.

Conclusions

This study revealed the potential efficacy of a DOX-nano drug delivery system for the treatment of HCC, using HepG2/DOX cells and nude mice bearing HepG2/DOX xenografts.

Efficient and clean preparation of rare prosaikogenin D by enzymatic hydrolysis of saikosaponin B2 and response surface methodology optimization

Prosaikogenin D, a rare secondary saponin in Radix Bupleuri, has much higher in vivo bioactivities than its original glycoside saikosaponin B₂. Its preparation methods, such as conventional acid hydrolysis and column chromatograph, are unfriendly to environment with serious pollution and undesired products. The aim of this study was to establish an efficient and clean approach for convenient preparation of this rare steroid saponin based on the enzymatic hydrolysis. Cellulase was selected from four commercial enzymes due to its higher hydrolysis performance. Then the hydrolysis conditions were optimized by response surface methodology after preliminary investigation on affecting factors by single-factor experiments. The reaction system was constructed by 100 μg/mL of saikosaponin B₂ and 8.00 mg/mL of cellulase, which was incubated in HAc-NaAc buffer (pH 4.7) at 60 °C for 33 h. Consequently, a high conversion ratio of the substrate has been achieved at 95.04 %. The newly developed strategy is an efficient and clean approach for the preparation of prosaikogenin D and it is a promising technology in industrial application.

Saikosaponin C exerts anti-HBV effects by attenuating HNF1α and HNF4α expression to suppress HBV pgRNA synthesis

Objective

Saikosaponin c (SSc), a compound purified from the traditional Chinese herb of Radix Bupleuri was previously identified to exhibit anti-HBV replication activity. However, the mechanism through which SSc acts against HBV remains unknown. In this study, we investigated the mechanism of SSc mediated anti-HBV activity.

Methods

HepG2.2.15 cells were cultured at 37 ℃ in the presence of 1–40 μg/mL of SSc or DMSO as a control. The expression profile of HBV markers, cytokines, HNF1α and HNF4α were investigated by real-time quantitative PCR, Elisa, Western blot and Dot blotting. Knockdown of HNF1α or HNF4α in HepG2.2.15 cells was mediated by two small siRNAs specifically targeting HNF1α or HNF4α.

Results

We found that SSc stimulates IL-6 expression, leading to attenuated HNF1α and HNF4α expression, which further mediates suppression of HBV pgRNA synthesis. Knockdown of HNF1α or HNF4α in HepG2.2.15 cells by RNA interference abrogates SSc’s anti-HBV role. Moreover, SSc is effective to both wild-type and drug-resistant HBV mutants.

Conclusion

SSc inhibits pgRNA synthesis by targeting HNF1α and HNF4α. These results indicate that SSc acts as a promising compound for modulating pgRNA transcription in the therapeutic strategies against HBV infection.

Electronic supplementary material

The online version of this article (10.1007/s00011-019-01284-2) contains supplementary material, which is available to authorized users.

Saikosaponin b2 enhances the hepatotargeting effect of anticancer drugs through inhibition of multidrug resistance-associated drug transporters

Aims: Vinegar-baked Radix Bupleuri (VBRB) potentiates the activity of anticancer drugs in the liver by increasing their hepatic distribution. However, this phenomenon may be associated with drug transporters. We investigated the effect of saikosaponin b2 (SSb2; the main component of VBRB) on the activity and expression of different drug transporters in both normal cells and those that overexpress the transporter.

Main methods: The activities of transporters were analyzed by concentration of their cellular substrates. Concentrations of colchicine (substrate of Pgp and MRP1) and cisplatin (substrate of OCT2 and MRP2) were determined by high-performance liquid chromatography (HPLC). The concentration of rhodamine B was determined by flow cytometry. The expression of transporter gene and protein were determined by qRT-PCR and Western blotting analysis.

Key findings: SSb2 increased colchicine efflux in HEK293 cells by primarily increasing Mrp1 activity, independent of gene and protein expression. SSb2 enhanced Mrp2 function and increased cisplatin efflux in BRL3A cells by upregulating Mrp2 gene expression, with a marginal effect on Pgp in normal cells. SSb2 increased OCT2 activity in OCT2-HEK293 cells by increasing the expression of OCT2 protein and mRNA; however, SSb2 inhibited MRP2 activity in MRP2-HEK293 cells by decreasing MRP2 protein expression, and decreased Pgp and MRP1 activity in Pgp- and MRP1-HEK293 cells.

Significance: SSb2 might potentially be the key active component of VBRB that enhances the hepatotargeting of anticancer drugs through the inhibition of multidrug resistance-associated drug transporters (Pgp, MRP1, and MRP2) in an environment-dependent manner.

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.

Saikosaponins A, C and D enhance liver-targeting effects of anticancer drugs by modulating drug transporters

Vinegar-baked Radix Bupleuri (VBRB) is clinically used to enhance the pharmacological activity of drugs used to treat liver diseases. Our previous study demonstrated that this effect is dependent on increased drug accumulation in the liver; however, the underlying mechanism remains unclear. We hypothesize that VBRB mediated its effects by altering drug transporters. Thus, the present study was designed to determine the effects of VBRB's main components, saikosaponin A, C, and D, on drug transporters. Transporter activity was determined by measuring the intracellular concentration of transporter substrates. Protein and mRNA levels were measured by Western blot and qPCR, respectively. Colchicine was used as the substrate for P-glycoprotein (Pgp) and multidrug resistance protein (MRP) 1, cisplatin was used as the substrate for Mrp2 and organic cation transporters 2 (Oct2), and verapamil and MK571 were used as inhibitors of Pgp and MRP1, respectively. Saikosaponin A, C, and D differentially affected transporter activity. All of the saikosaponins inhibited Pgp activity in Pgp over-expressing HEK293 cells and increased substrate uptake of OCT2 in OCT2 over-expressing HEK293. Saikosaponin C and D inhibited MRP2 activity in HEK293 cells and BRL 3A cell with high MRP2 expression; saikosaponin A increased colchicine accumulation in GSH-stimulated HEK293 cells, but decreased colchicine uptake in HEK293 cells. Saikosaponin D inhibited MRP1 activity in GSH-stimulated HEK293 cells, but marginally affected the uptake of colchicine in HEK293 cells. In conclusion, saikosaponins play a role in VBRB's induced liver targeting effect through affecting drug transporters with a transporter expression amount depending manner.

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.