Saikosaponin-d increases the radiosensitivity of smmc-7721 hepatocellular carcinoma cells by adjusting the g0/g1 and g2/m checkpoints of the cell cycle

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 induces the pyroptosis of lung cancer by increasing ROS and activating the NF-κB/NLRP3/caspase-1/GSDMD pathway

Saikosaponin-D (SSD), an active ingredient in Bupleurum chinense, exerts anticancer effects in various cancers by inhibiting cancer proliferation and inducing apoptosis. However, whether SSD can induce other forms of cell death is unknown. The current study aims to demonstrate that SSD can induce pyroptosis in non-small-cell lung cancer. In this study, HCC827 and A549 non-small-cell lung cancer cells were treated with different concentrations of SSD for 1.5 h. HE and TUNEL staining were used to verify cell damage caused by SSD. Immunofluorescence and western blotting were performed to verify the effect of SSD on the NF-κB/NLRP3/caspase-1/gasdermin D (GSDMD) pathway. Changes in inflammatory factors were detected by ELISAs. Finally, the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) was introduced to verify that SSD induces pyroptosis through the ROS/NF-κB pathway. The results of the HE and TUNEL staining showed that SSD resulted in balloon-like swelling of NSCLC cells accompanied by increased DNA damage. Immunofluorescence and western blot assays confirmed that SSD treatment activated the NLRP3/caspase-1/GSDMD pathway, stimulated an increase in ROS levels and activated NF-κB in lung cancer cells. The ROS scavenger N-acetylcysteine significantly attenuated SSD-induced NF-κB/NLRP3/caspase-1/GSDMD pathway activation and inhibited the release of the inflammatory cytokines IL-1β and IL-18. In conclusion, SSD induced lung cancer cell pyroptosis by inducing ROS accumulation and activating the NF-κB/NLRP3/caspase-1/GSDMD pathway. These experiments lay the foundation for the application of SSD in the treatment of non-small-cell lung cancer and regulation of the lung cancer immune microenvironment.

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.

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.

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

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

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

Quantitative Analysis and Differential Evaluation of Radix Bupleuri Cultivated in Different Regions Based on HPLC-MS and GC-MS Combined with Multivariate Statistical Analysis

The quality of Radix Bupleuri is greatly affected by its growing environment. In this study, Radix Bupleuri samples that were harvested from seven different regions across northwest China were examined by high-performance liquid chromatography (HPLC) and gas chromatography (GC) coupled with mass spectrometry (MS) to reveal significant differences in quality contributed by the cultivation region. An HPLC-MS method was firstly established and used in the multiple reaction monitoring mode for the quantitative analysis of five saikosaponins in Radix Bupleuri so as to evaluate the difference in the absolute content of saikosaponins attributable to the cultivation region. The effect on the components of Radix Bupleuri was further investigated based on the profiles of the representative saponins and volatile compounds, which were extracted from the Radix Bupleuri samples and analyzed by HPLC-MS and GC-MS. Multivariate statistical analysis was employed to differentiate the Radix Bupleuri samples cultivated in different regions and to discover the differential compositions. The developed quantitative method was validated to be accurate, stable, sensitive, and repeatable for the determination of five saikosaponins. Further statistical tests revealed that the collected Radix Bupleuri samples were distinctly different from each other in terms of both saponins and volatile compounds, based on the provinces where they were grown. In addition, twenty-eight saponins and fifty-eight volatile compounds were identified as the differentially accumulated compositions that contributed to the discrimination of the Radix Bupleuri samples. The Radix Bupleuri samples grown in Shouyang county showed the highest content of saikosaponins. All of the results indicated that the cultivation region significantly affected the accumulation and diversity of the main chemical components of Radix Bupleuri. The findings of this research provide insights into the effect of the cultivation region on the quality of Radix Bupleuri and the differentiation of Radix Bupleuri cultivated in different regions based on the use of HPLC-MS and GC-MS combined with multivariate statistical analysis.

Verbascoside enhances radiosensitivity of hepatocellular carcinoma cells through regulating miR-101-3p/Wee1 axis

Verbascoside is a kind of phenylpropanoid glycoside derived from multiple medicinal plants, exerting anti-tumor effects in diverse human malignancies. However, the function of Verbascoside on the radiosensitivity of hepatocellular carcinoma (HCC) cells remains unknown. Human Huh7 and HepG2 cell lines were treated with Verbascosideis, and cell viability was detected with cell counting kit-8 (CCK-8) assay. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect miR-101-3p expression, and Western blot was used to quantify the expression of WEE1 G2 checkpoint kinase (WEE1). Then, CCK-8 and flow cytometry assays were used to detect the proliferation and apoptosis of HCC cells after Verbascoside and X-ray combined treatment, and the expressions of WEE1 and apoptosis-related proteins Bax and Bcl-2 were detected by Western blot. Verbascoside could improve the radiosensitivity of HCC cells in a dose-dependent manner. Verbascoside increased the expression of miR-101-3p but reduced WEE1 expression in HCC cells. Additionally, WEE1 was identified as a target of miR-101-3p. MiR-101-3p inhibition or WEE1 overexpression could reverse the effect of Verbascoside on the viability and apoptosis of HCC cells. Verbascoside increases the radiosensitivity of hepatocellular carcinoma cells via modulating miR-101-3p/WEE1 axis.

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.

Effects of dietary inclusion of Radix Bupleuri extract on the growth performance, and ultrastructural changes and apoptosis of lung epithelial cells in broilers exposed to atmospheric ammonia

To explore whether Radix Bupleuri extract (RBE) could protect lung injury of broilers under ammonia (NH3) exposure, 360 one-d-old male broilers were randomly allocated to four groups of six replicates each in a 2 × 2 factorial design with two diets (the basal diet [control; CON] and the basal diet supplemented with RBE [RB]) and two air conditions (normal condition [<2 ppm of NH3; NOR] and NH3 exposure [70 ppm of NH3; NH70]). The RB diet contained 80 mg saikosaponins/kg diet. On day 7, the lung tissues were collected and the lung epithelial cells (LEC) were isolated. Our experimental results showed that the NH3 exposure decreased body weight gain and feed intake irrespective of dietary treatments during days 1 to 7. However, the RBE addition decreased feed consumption to body weight gain ratio in broilers under NH70 conditions. In the LEC of CON-fed broilers under NH70 conditions, Golgi stacks showed the dilation of cisternaes and reduced secretory vesicles, mitochondria enlarged, the inner membrane of mitochondria became obscure, and the cristae of mitochondria ruptured, whereas only a mild enlargement of Golgi cisternaes and the part rupture of mitochondrial cristaes occurred in the LEC of RB-fed broilers under NH70 conditions. The NH3 exposure increased malondialdehyde (MDA) level, but decreased total antioxidant capacity (T-AOC) in the lungs of CON-fed broilers. However, the RBE addition decreased MDA level and increased T-AOC in the lungs of broilers under NH70 conditions. Simultaneously, the NH3 exposure increased apoptotic rate (AR), mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) level in the isolated LEC of CON-fed broilers. The RBE addition decreased AR, MMP, and ROS in the isolated LEC of broilers under NH70 condition. Besides, the NH3 exposure increased mRNA expression of B-cell lymphoma-2 associated X protein (BAX), caspase-3, and tumor necrosis factor α (TNF-α), but increased interferon γ (IFN-γ) mRNA abundance in the lungs of CON-fed broilers. The RBE supplement decreased mRNA levels of BAX, caspase-3, and TNF-α, but increased IFN-γ, interleukin (IL)-4, and IL-17 mRNA levels in the lungs of broilers under NH70 conditions. These results indicated that dietary RBE addition alleviated NH3 exposure-induced intercellular ultrastructural damage via mitochondrial apoptotic pathway, possibly due to RBE-induced increase of antioxidant capacity and immunomodulatory function in the lungs of broilers under NH3 exposure.

Effects and Mechanisms of Saikosaponin D Improving the Sensitivity of Human Gastric Cancer Cells to Cisplatin

Gastric cancer (GC) is the second leading cause of cancer deaths around the world. Chemoresistance is an important reason for poor prognosis of GC. Saikosaponin D (SSD) is a natural constituent from Radix Bupleuri and exhibits various activities including antitumors. This study investigated the effects and the mechanisms of SSD on cisplatin (cis-diamminedichloroplatinum, DDP) sensitivity of GC cells. Findings suggested that SSD could promote the inhibitory effect of DDP on proliferation and invasion and increase DDP-induced apoptosis in SGC-7901 and DDP-resistant cell line SGC-7901/DDP. We further identified that SSD increased levels of LC3 B and cleaved caspase 3 and decreased levels of p62, IKK β, p-IκB α, and NF-κB p65, suggesting that SSD might inhibit the IKK β/NF-κB pathway and induce both cell autophagy and apoptosis in SGC-7901 and SGC-7901/DDP. A further study indicated that SSD enhanced the effect of DDP-induced cleaved caspase 3 level rise and NF-κB pathway suppression, especially in SGC-7901/DDP cells. Conclusively, SSD enhanced DDP sensitivity of GC cells; the potential molecular mechanisms were that SSD-induced apoptosis and autophagy and inhibited the IKK β/NF-κB pathway in GC cells. These findings suggested that SSD might contribute to overcoming DDP resistance in GC treatment.

Saikosaponin-d increases radiation-induced apoptosis of hepatoma cells by promoting autophagy via inhibiting mTOR phosphorylation

Objective: The aim of this study was to analyze the effects of saikosaponin-d (SSd) on autophagy activity and radiosensitivity of hepatoma cells, and to elucidate its related molecular mechanisms. Methods: The growth of SMMC-7721 and MHCC97L hepatoma cells were detected by clonal formation and survival fraction. Flow cytometry was used to detect the changes of apoptosis of hepatoma cells. The morphological changes of autophagy of hepatoma cells were observed by transmission electron microscopy and were further quantitatively detected by laser confocal microscopy. The expressions of related proteins were detected by Western blotting. Results: SSd can significantly increase the apoptosis of hepatoma cells induced by radiation and inhibit the proliferation of hepatoma cells. The addition of the autophagy inhibitor chloroquine (CQ) or an mTOR agonist (MHY1485), which could reduce the promoting effect of SSd on radiation-induced apoptosis and inhibitory effect on the proliferation of hepatoma cells. Transmission electron microscopy and confocal microscopy results also showed that the number of autophagosomes was significantly higher in the radiation and SSd co-treatment group than in the radiotherapy or SSd alone group; however, the effect of SSd on autophagy in hepatoma cells was decreased after adding MHY1485, siRNA-P53 or AMPK inhibitor (Compound C). Western blot analysis showed that after the addition of SSd, the phosphorylation of mTOR was significantly decreased by radiation, the expression of the autophagy-related proteins LC3-II and Beclin-1 was increased, p62 was decreased, and the expression of cleaved caspase-3 and cleaved PARP was enhanced; this effect of SSd was partially reversed after the addition of MHY1485, siRNA-P53 or Compound C. Conclusions: SSd increases radiation-induced apoptosis of hepatoma cells by promoting autophagy via inhibiting mTOR phosphorylation and providing a possible potential approach for radiosensitization therapy of liver cancer.

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.

Botany, traditional uses, phytochemistry, analytical methods, processing, pharmacology and pharmacokinetics of Bupleuri Radix: A systematic review

Bupleuri Radix (BR) is the dry root of Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd. It has the functions of evacuation and antipyretic, soothing liver and relieving depression and often used to treat cold fever, chest and rib swelling pain, irregular menstruation, uterine prolapse, rectocele and other diseases. In this paper, the botany, traditional application, phytochemistry, pharmacology and toxicity of BR were reviewed. On the basis of limited literature, the analytical method, quality control, processing method, processing effect and pharmacokinetics of BR were summarized and analyzed for the first time. This review makes an in-depth discussion on the shortcomings of the current research on BR, and puts forward its own views and solutions. This has never been summarized in the previous review of BR. It is of great practical significance for future scholars to find a breakthrough point in the study of BR. So far, its mechanism has not been satisfactorily explained. Moreover, the comprehensive quality evaluation and multi-target network pharmacology of BR need to be further studied. In the future, more in vitro and in vivo experiments are needed to give full play to the therapeutic potential of BR.

Saikosaponin-d Inhibits the Hepatoma Cells and Enhances Chemosensitivity Through SENP5-Dependent Inhibition of Gli1 SUMOylation Under Hypoxia

Chemosensitivity is one of the key factors affecting the therapeutic effect on cancer, but the clinical application of corresponding drugs is rare. Hypoxia, a common feature of many solid tumors, including hepatocellular carcinoma (HCC), has been associated with resistance to chemotherapy in part through the activation of the Sonic Hedgehog (SHh) pathway. Hypoxia has also been associated with the increased SUMOylation of multiple proteins, including GLI family proteins, which are key mediators of SHh signaling, and has become a promising target to develop drug-resistant drugs for cancer treatment. However, there are few target drugs to abrogate chemotherapy resistance. Saikosaponin-d (Ssd), one of the main bioactive components of Radix bupleuri, has been reported to exert multiple biological effects, including anticancer activity. Here, we first found that Ssd inhibits the malignant phenotype of HCC cells while increasing their sensitivity to the herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) drug system under hypoxia in vitro and in vivo. Furthermore, we had explored that GLI family activation and extensive protein SUMOylation were characteristics of HCC cells, and hypoxia could activate the SHh pathway and promote epithelial-mesenchymal transition (EMT), invasion, and chemosensitivity in HCC cells. SUMOylation is required for hypoxia-dependent activation of GLI proteins. Finally, we found that Ssd could reverse the effects promoted by hypoxia, specifically active sentrin/small ubiquitin-like modifier (SUMO)-specific protease 5 (SENP5), a SUMO-specific protease, in a time- and dose-dependent manner while inhibiting the expression of SUMO1 and GLI proteins. Together, these findings confirm the important role of Ssd in the chemoresistance of liver cancer, provide some data support for further understanding the molecular mechanisms of Ssd inhibition of malignant transformation of HCC cells, and provide a new perspective for the application of traditional Chinese medicine in the chemical resistance of liver cancer.

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-d Increases the Radiosensitivity of Hepatoma Cells by Adjusting Cell Autophagy

Radiotherapy for liver cancer can affect the level of autophagy in cells, and effective autophagy regulation can increase the radiosensitivity of liver cancer cells.Saikosaponin-d (SSd) is an effective active ingredient extracted from traditional Chinese medicine Bupleurum. We have confirmed previously in vitro and in vitro experiments that SSd can significantly induce apoptosis of liver cancer cells, increase the radiosensitivity of liver cancer cells.This study explored the role of autophagy in SSd-mediated radiosensitivity of liver cancer cells. MTT and clone formation experiments showed that radiation can inhibit the proliferation of hepatoma cells and reduce the colony formation of hepatoma cells. After the addition of SSd, the inhibitory effect of radiation on the proliferation and clonal formation of hepatoma cells was further enhanced. However, the addition of the autophagy inhibitor chloroquine or mTOR agonist can partially reverse the inhibitory effect of the combined treatment of SSd with radiation on the proliferation of hepatoma cells. Similarly, transmission electron microscopy and laser confocal microscopy showed that after the addition of SSd, the number of radiation-induced autophagosomes increased significantly in hepatoma cells and the intervention of mTOR agonist can reduce the formation of autophagosomes in hepatoma cells.In addition,Western blot analysis presented that radiation significantly increased LC3-II levels. Especially when SSd is added, LC3-II levels is further increased. Our data indicate that SSd can inhibit the growth of liver cancer cells and enhance cell radiosensitivity by inducing autophagy formation.

Untargeted Metabolomics Study of the In Vitro Anti-Hepatoma Effect of Saikosaponin d in Combination with NRP-1 Knockdown

Saikosaponin d (SSd) is one of the main active ingredients in Radix Bupleuri. In our study, network pharmacology databases and metabolomics were used in combination to explore the new targets and reveal the in-depth mechanism of SSd. A total of 35 potential targets were chosen through database searching (HIT and TCMID), literature mining, or chemical similarity predicting (Pubchem). Out of these obtained targets, Neuropilin-1 (NRP-1) was selected for further research based on the degree of molecular docking scores and novelty. Cell viability and wound healing assays demonstrated that SSd combined with NRP-1 knockdown could significantly enhance the damage of HepG2. Metabolomics analysis was then performed to explore the underlying mechanism. The overall difference between groups was quantitatively evaluated by the metabolite deregulation score (MDS). Results showed that NRP-1 knockdown exhibited the lowest MDS, which demonstrated that the metabolic profile experienced the slightest interference. However, SSd alone, or NRP-1 knockdown in combination with SSd, were both significantly influenced. Differential metabolites mainly involved short- or long-chain carnitines and phospholipids. Further metabolic pathway analysis revealed that disturbed lipid transportation and phospholipid metabolism probably contributed to the enhanced anti-hepatoma effect by NRP-1 knockdown in combination with SSd. Taken together, in this study, we provided possible interaction mechanisms between SSd and its predicted target NRP-1.

Neural network analysis of Chinese herbal medicine prescriptions for patients with colorectal cancer

Traditional Chinese Medicine (TCM) is an experiential form of medicine with a history dating back thousands of years. The present study aimed to utilize neural network analysis to examine specific prescriptions for colorectal cancer (CRC) in clinical practice to arrive at the most effective prescription strategy. The study analyzed the data of 261 CRC cases recruited from a total of 141,962 cases of renowned veteran TCM doctors collected from datasets of both the DeepMedic software and TCM cancer treatment books. The DeepMedic software was applied to normalize the symptoms/signs and Chinese herbal medicine (CHM) prescriptions using standardized terminologies. Over 20 percent of CRC patients demonstrated symptoms of poor appetite, fatigue, loose stool, and abdominal pain. By analyzing the prescription patterns of CHM, we found that Atractylodes macrocephala (Bai-zhu) and Poria (Fu-ling) were the most commonly prescribed single herbs identified through analysis of medical records, and supported by the neural network analysis; although there was a slight difference in the sequential order. The study revealed an 81.9% degree of similarity of CHM prescriptions between the medical records and the neural network suggestions. The patterns of nourishing Qi and eliminating dampness were the most common goals of clinical prescriptions, which corresponds with treatments of CRC patients in clinical practice. This is the first study to employ machine learning, specifically neural network analytics to support TCM clinical diagnoses and prescriptions. The DeepMedic software may be used to deliver accurate TCM diagnoses and suggest prescriptions to treat CRC.

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.

Saikosaponin D inhibits proliferation of human osteosarcoma cells via the p53 signaling pathway

Saikosaponin D (SSd), the major monomeric terpenoid extracted from Radix bupleuri, a traditional Chinese medicinal herb, exerts various pharmacological properties, including antitumor, anti-inflammatory and antiviral. The present study aimed to investigate the role of SSd in human osteosarcoma (OS) cell growth. In the investigation MTS and EdU assays were applied and flow cytometric analyses of cell cycle and apoptosis were performed. Western blotting and reverse transcription-quantitative polymerase chain reaction analyses were used to explore the underlying mechanisms of SSd on cell cycle transition and p53 signaling. Here, it was demonstrated that SSd administration at 80 µmol/l significantly inhibited 143B and MG-63 proliferation. Furthermore, SSd significantly increased the percentage of 143B and MG-63 cells in G₀-G₁ phase and the number of apoptosis cells compared with the control group. Data further demonstrated that SSd treatment upregulated mRNA and protein levels of tumor protein 53 (p53) and its downstream targets, including p21, p27, B-cell lymphoma-2-like protein 4 and cleaved caspase-3, and downregulated mRNA and protein levels of cyclinD1. The results suggested that SSd was a functional tumor suppressor and inhibited OS proliferation via activation of the p53 signaling pathway and may be used in the treatment of osteosarcoma in future.

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.

Shikonin causes apoptosis by disrupting intracellular calcium homeostasis and mitochondrial function in human hepatoma cells

Shikonin is known to suppress proliferation and induce apoptosis in a variety of cancer cell lines. In the present study, SMMC-7721 human hepatocellular carcinoma cells were treated with shikonin (1, 2 or 4 µM) for 12–48 h. Cell morphological alterations and DNA damage were determined. Furthermore, changes in cell cycle, mitochondrial transmembrane potential, calcium homeostasis and levels of reactive oxygen species were measured. Shikonin-treated SMMC-7721 cells exhibited morphological changes and DNA damage. Shikonin inhibited cell proliferation causing cell cycle arrest at the G₀/G₁ phase and induced apoptosis in a dose- and time-dependent manner. Shikonin-induced apoptosis was associated with activation of caspases-3, −8 and −9, elevated levels of intracellular Ca²⁺ and reactive oxygen species, reduced mitochondrial membrane potential and enhanced efflux of Ca²⁺ and K⁺. Gene expression B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), p53 and caspase-3 was up-regulated, whereas Bcl-2 expression was downregulated. Shikonin caused apoptosis by inhibiting cell cycle progression, disrupting Ca²⁺ homeostasis, inducing oxidative stress and triggering mitochondrial dysfunction. Activation of caspases-3, −8 and −9, K⁺ efflux, and regulation of Bax, Bcl-2, p53 and caspase-3 expression are involved in the process. These results provide in-depth insight into the mechanisms of action of shikonin in the treatment of cancer.

Andrographolide radiosensitizes human esophageal cancer cell line ECA109 to radiation in vitro

To explore the radiosensitivity of andrographolide on esophageal cancer cell line ECA109. The inhibition effects of andrographolide were measured using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. Clonogenic survival assay was used to evaluate the effects of andrographolide on the radiosensitivity of esophageal cancer cells. Immunofluorescence was employed to examine Bax expression. The changes in cell cycle distribution and apoptosis were assayed using flow cytometry. The expression of NF-κb/Cleaved-Caspase3/Bax/Bcl-2 was measured using Western blot analysis. DNA damage was detected via γ-H2AX foci counting. With a clear dose and time effects, andrographolide was found to inhibit the proliferation of esophageal cell line ECA109. The results of the clonogenic survival assay show that andrographolide could markedly enhance radiosensitivity (P < 0.05) with a sensitizing enhancement ratio of 1.28. Andrographolide caused a dose-dependent increase in Cleaved-Caspase3/Bax protein expression and a decrease in Bcl-2/NF-κb expression. Apoptosis in andrographolide-treated ECA-109 increased significantly compared with the apoptosis in the simple drug and radiation combined with drug groups (P < 0.001; P < 0.05). Moreover, compared with the independent radiation group, the andrographolide combined with radiation group increased the number of DNA double chain breaks. Andrographolide can increase the radiosensitivity of esophageal cell line ECA109. This result may be associated with the decrease in the NF-κb level and the induced apoptosis of esophageal cancer cells.

The correlation of virulence, pathogenicity, and itraconazole resistance with SAP activity in Candida albicans strains

The relationship between SAP2 activity and drug resistance in Candida albicans was investigated by using itraconazole-resistant and itraconazole-sensitive C. albicans isolates. The precipitation zones were measured to analyze SAP2 activity. Mice were classified into itraconazole-resistant and -sensitive C. albicans isolate groups, and a control group, with their survival and mortality rate being observed over 30 days. The relative expression levels of CDR1, CDR2, MDR1, and SAP2 were measured using RT-PCR. It was found that the secreted aspartyl proteinase activity of itraconazole-resistant C. albicans strains was significantly higher than that of itraconazole-sensitive C. albicans strains (P < 0.001). A significantly higher mortality rate was recorded for mice treated with itraconazole-resistant C. albicans than for mice treated with itraconazole-sensitive C. albicans. In regards to the CDR1, CDR2, and MDR1 genes, there was no significant difference between the 2 groups of mice. Positive correlations between SAP2 and MDR1 and between CDR1 and CDR2 were found. The high expression level of SAP2 may relate to the virulence, pathogenicity, and resistance of C. albicans.

Integrated Treatment of Aqueous Extract of Solanum nigrum-Potentiated Cisplatin- and Doxorubicin-Induced Cytotoxicity in Human Hepatocellular Carcinoma Cells

Chemotherapy is the main approach for treating advanced and recurrent hepatocellular carcinoma (HCC), but the clinical performance of chemotherapy is limited by a relatively low response rate, drug resistance, and adverse effects that severely affect the quality of life of patients. The aqueous extract of Solanum nigrum (AE-SN) is a crucial ingredient in some traditional Chinese medicine (TCM) formulas for treating cancer patients and exhibits antitumor effects in human HCC cells. Therefore, this study examined the tumor-suppression efficiency of AE-SN integrated with a standard chemotherapeutic drug, namely, cisplatin or doxorubicin, in human HCC cells, namely, Hep3B and HepJ5. The results suggested that the integrated treatment with AE-SN-potentiated cisplatin and doxorubicin induced cytotoxicity through the cleavage of caspase-7 and accumulation of microtubule-associated protein-1 light chain-3 A/1B II (LC-3 A/B II), which were associated with apoptotic and autophagic cell death, respectively, in both the Hep3B and HepJ5 cells. In conclusion, AE-SN can potentially be used in novel integrated chemotherapy with cisplatin or doxorubicin to treat HCC patients.

Saikosaponin‑d suppresses the expression of cyclooxygenase‑2 through the phospho‑signal transducer and activator of transcription 3/hypoxia‑inducible factor‑1α pathway in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common malignancies and accounts for ~6% of all types of human cancer worldwide, particularly in Asia. The incidence and mortality rates in the USA have also rapidly increased. Saikosaponin‑d (SSD), a saponin derivative extracted from several species of Bupleurum (Umbelliferae), possesses unique biological activities, including anti‑inflammatory, antihepatitic and immunomodulatory effects. Our previous studies have demonstrated that SSD inhibits the proliferation and induces the apoptosis of HCC SMMC‑7721 cells by downregulating the expression of cyclooxygenase (COX)‑2 and decreasing the production of prostaglandin E2. However, the specific mechanism underlying how SSD controls the expression of COX‑2 remains to be elucidated. In the present study, it was demonstrated that hypoxia inducible factor‑1α (HIF‑1α) was responsible for the expression of COX‑2 under hypoxic conditions in HCC cells, and the activation of signal transducer and activator of transcription 3 (STAT3) was required for the expression of HIF‑1α. SSD treatment inhibited STAT3 activation [phosphorylation of STAT3 (p‑STAT3)], reduced the protein level of HIF‑1α and decreased the expression of COX‑2. These results suggested that SSD may target HCC cells by suppressing the expression of COX‑2 through the p‑STAT3/HIF‑1α pathway.

Low-dose splenic radiation inhibits liver tumor development of rats through functional changes in CD4+CD25+Treg cells

The increased number of CD4(+)CD25(+)Treg cells in tumor local and peripheral splenic tissues is related to the low immune function as well as to tumor recurrence and metastasis. Our pre-clinical studies showed that low-dose radiation (LDR) of the spleen in liver cancer patients significantly improves immune functions. However, the molecular mechanisms of such radiation remained ill defined. This study explores the role of CD4(+)CD25(+)Treg cells in radiation-induced immunomodulatory effects. Using the diethylnitrosamine (DEN)-induced rat liver tumor model and in vitro cell experiments, the percentage of CD4(+)CD25(+)Treg/CD4(+) cells in the blood and the expressions of Foxp3(+), IL-10, TGF-β, and cytotoxic T lymphocyte-associated antigen-4(CTLA-4) in spleen and liver tumors significantly decreased after LDR of the spleen in rats with liver cancer. The tumors became smaller than those in the non-radiated group, with both showing a parallel relation. Flow cytometry and MTT results revealed that LDR failed to inhibit CD4(+)CD25(+)Treg cell proliferation. Conversely, apoptosis was reduced and proliferation was stimulated. This process also changed CTLA-4 molecule expression on the surfaces of CD4(+)CD25(+)Treg cells and reduced their inhibitory function against CD4(+)CD25(-)T cell proliferation, and the suppression function of CD4(+)CD25(+)Treg cells was further weakened with the introduction of the CTLA-4 inhibitor. Findings demonstrate that the reduction of CTLA-4 expression on the CD4(+)CD25(+)Treg cell surface and the further inhibition of cell function may be considered as important regulators of LDR-induced immunomodulatory effects. This study provides experimental evidence to elucidate the immune enhancement induced by this process and presents a novel method for liver cancer immunotherapy.

Effects of SSd combined with radiation on inhibiting SMMC-7721 hepatoma cell growth

Background

The aim of this study was to investigate the effects of Saikosaponin-d (SSd) combined with radiotherapy on SMMC-7721 hepatoma cell lines and its mechanism.

Material/Methods

SMMC-7721 hepatoma cell lines are selected in our research. With MTT (methylthiazolyldiphenyl-tetrazolium-bromide) method, the effects of SSd and radiation on inhibiting SMMC-7721 cell growth were investigated. We also used transmission electron microscopy (TEM) to observe ultrastructural changes of cells. Colorimetry methods were used to measure content changes of glutathione (GSH) and malondialdehyde (MDA) in cells.

Results

Both SSd and radiation inhibited the growth of SMMC-7721 cells. The combination of SSd and radiotherapy had a time-dependent synergistic effect. Radiation caused ultrastructural damage to cells, and the damage was enhanced in combination with SSd. Radiation decreased the GSH content and increased the MDA content in cells, and this effect was suppressed after the intervention of SSd.

Conclusions

SSd can inhibit the growth of SMMC-7721 hepatoma cell lines in vitro. Additionally, it significantly enhances the effects of radiation on inhibiting the growth of SMMC-7721 hepatoma cell lines, and up-regulates the antioxidant level after the radiotherapy. Thus, SSd could be an ideal radiotherapy sensitizer for the treatment of liver cancer.

Shikonin induces cell cycle arrest in human gastric cancer (AGS) by early growth response 1 (Egr1)-mediated p21 gene expression

ETHNOPHARMACOLOGICAL RELEVANCE

Lithospermum erythrorhizon, a naphthoquinone compound derived from a shikonin, has long been used as traditional Chinese medicine for treatment of various diseases, including cancer. To evaluate the cytotoxic effects of shikonin on AGS gastric cancer cells via induction of cell cycle arrest.

MATERIALS AND METHODS

We observed the effects of 12.5-100 ng/mL dosage of shikonin treatment on AGS cancer cell line with the incubation time of 6h. Cytotoxic effects were assessed by measuring the changes in the intracellular ROS, appearance of senescence phenotype, cell cycle progression, CDK and cyclins expression levels upon shikonin treatment. We also examined upon the activation of Egr1-mediated p21 expression, by siRNA transfection, Luciferase assay, and ChIP assay.

RESULTS

In this study, we found that shikonin inhibits cell proliferation by arresting cell cycle progression at the G2/M phase via modulation of p21 in AGS cells. Also, our results revealed that the p21 gene was transactivated by early growth response1 (Egr1) in response to the shikonin treatment. Transient Egr1 expression enhanced shikonin-induced p21 promoter activity, whereas the suppression of Egr1 expression by small interfering RNA attenuated the ability of shikonin to induce p21 promoter activity.

CONCLUSION

Our results suggested that the anti-proliferative activity of shikonin was due to its ability to induce cell cycle arrest via Egr1-p21 signaling pathway. Thus, the work stated here validates the traditional use of shikonin in the treatment of cancer.