Enhancement of gemcitabine sensitivity in intrahepatic cholangiocarcinoma through Saikosaponin-a mediated modulation of the p-AKT/BCL-6/ABCA1 axis.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) remains a significant challenge in cancer therapy, especially due to its resistance to established treatments like Gemcitabine, necessitating novel therapeutic approaches. METHODS: This study utilized Gemcitabine-resistant cell lines, patient-derived organotypic tumor spheroids (PDOTs), and patient-derived xenografts (PDX) to evaluate the effects of Saikosaponin-a (SSA) on ICC cellular proliferation, migration, apoptosis, and its potential synergistic interaction with Gemcitabine. Techniques such as transcriptome sequencing, Luciferase reporter assays, and molecular docking were employed to unravel the molecular mechanisms. RESULTS: SSA exhibited antitumor effects in both in vitro and PDX models, indicating its considerable potential for ICC treatment. SSA markedly inhibited ICC progression by reducing cellular proliferation, enhancing apoptosis, and decreasing migration and invasion. Crucially, it augmented Gemcitabine's efficacy by targeting the p-AKT/BCL6/ABCA1 signaling pathway. This modulation led to the downregulation of p-AKT and suppression of BCL6 transcriptional activity, ultimately reducing ABCA1 expression and enhancing chemosensitivity to Gemcitabine. Additionally, ABCA1 was validated as a predictive biomarker for drug resistance, with a direct correlation between ABCA1 expression levels and the IC50 values of various small molecule drugs in ICC gene profiles. CONCLUSION: This study highlights the synergistic potential of SSA combined with Gemcitabine in enhancing therapeutic efficacy against ICC and identifies ABCA1 as a key biomarker for drug responsiveness. Furthermore, the introduction of the novel PDOTs microfluidic model provides enhanced insights into ICC research. This combination strategy may provide a novel approach to overcoming treatment challenges in ICC.

Effects of Saikosaponin-A on Insulin Resistance in Obesity: Computational and Animal Experimental Study.

Obesity is known to be associated with increased inflammation and dysregulated autophagy, both of which contribute to insulin resistance. Saikosaponin-A (SSA) has been reported to exhibit anti-inflammatory and lipid-lowering properties. In this research, we employed a combination of computational modeling and animal experiments to explore the effects of SSA. Male C57BL/6 mice were categorized into four groups: normal diet, high-fat diet (HFD), HFD + atorvastatin 10 mg/kg, and HFD + SSA 10 mg/kg. We conducted oral glucose and fat tolerance tests to assess metabolic parameters and histological changes. Furthermore, we evaluated the population of Kupffer cells (KCs) and examined gene expressions related to inflammation and autophagy. Computational analysis revealed that SSA displayed high binding affinity to tumor necrosis factor (TNF)-α, nuclear factor (NF)-κB, fibroblast growth factor 21 (FGF21), and autophagy-related 7 (ATG7). Animal study demonstrated that SSA administration improved fasting and postprandial glucose levels, homeostatic model assessment of insulin resistance (HOMA-IR) index, as well as triglyceride, free fatty acid, total cholesterol, low-density lipoprotein cholesterol (LDL-C)-cholesterol, and high-density lipoprotein cholesterol (HDL-C)-cholesterol levels in HFD-fed mice. Moreover, SSA significantly reduced liver weight and fat accumulation, while inhibiting the infiltration and M1 activation of KCs. At the mRNA level, SSA downregulated TNF-α and NF-κB expression, while upregulating FGF21 and ATG7 expression. In conclusion, our study suggests that SSA may serve as a therapeutic agent for addressing the metabolic complications associated with obesity. This potential therapeutic effect is attributed to the suppression of inflammatory cytokines and the upregulation of FGF21 and ATG7.

In Vivo Evaluation of Self-assembled nano-Saikosaponin-a for Epilepsy Treatment.

Saikosaponin-a (SSa) exhibits antiepileptic effects. However, its poor water solubility and inability to pass through the blood-brain barrier greatly limit its clinical development and application. In this study, SSa-loaded Methoxy poly (ethylene glycol)-poly(ε-caprolactone) (MePEG-SSa-PCL) NPs were successfully prepared and characterized. Our objective was to further investigate the effect of this composite on acute seizure in mice. First, we confirmed the particle size and surface potential of the composite (51.00 ± 0.25 nm and - 33.77 ± 2.04 mV, respectively). Further, we compared the effects of various MePEG-SSa-PCL doses (low, medium, and high) with those of free SSa, valproic acid (VPA - positive control), and saline only (model group) on acute seizure using three different acute epilepsy mouse models. We observed that compared with the model group, the three MePEG-SSa-PCL treatments showed significantly lowered seizure frequency in mice belonging to the maximum electroconvulsive model group. In the pentylenetetrazol and kainic acid (KA) acute epilepsy models, MePEG-SSa-PCL increased both clonic and convulsion latency periods and shortened convulsion duration more effectively than equivalent SSa-only doses. Furthermore, hematoxylin-eosin and Nissl staining revealed considerably less neuronal damage in the hippocampal CA3 area of KA mice in the SSa, VPA, and three MePEG-SSa-PCL groups relative to mice in the model group. Hippocampal gamma-aminobutyric acid-A (GABA-A) receptor and cleaved caspase-3 expression levels in KA mice were significantly higher and lower, respectively, in the three MePEG-SSa-PCL treatment groups than in the model group. Thus, MePEG-SSa-PCL exhibited a more potent antiepileptic effect than SSa in acute mouse epilepsy models and could alleviate neuronal damage in the hippocampus following epileptic seizures, possibly via GABA-A receptor expression upregulation.

Saikosaponin A Changes Drug Resistance of A549/DDP Cells Through Wnt/β-Catenin Pathway / 中国实验方剂学杂志

Objective:To investigate the effect and mechanism of saikosaponin A （SSA） on the reversal of cisplatin （DDP） resistance in human lung cancer cell line A549/DDP. Methods:The resistance of A549 and A549/DDP cells to DDP and the inhibitory effects of SSA against the proliferation of A549 and A549/DDP cells were detected using cell counting kit-8 （CCK-8）. The apoptosis rates of A549/DDP cells treated with SSA or DDP or SSA combined with DDP and the changes in reactive oxygen species （ROS） were determined by flow cytometry. The mRNA expression levels of C-myc， B-cell lymphoma 2 （Bcl-2） and cysteinyl aspartate-specific protease-3 （Caspase-3） were detected by real-time polymerase chain reaction （Real-time PCR）， followed by the determination of <italic>β</italic>-catenin transcriptional activity using the TopFish dual-luciferase reporter assay system and the measurement of <italic>β</italic>-catenin protein expression in A549/DDP cells by Western blot. Results:The results of CCK-8 assay showed that the DDP resistance of A549/DDP cells was 12.82 times that of A549 cells （<italic>P</italic><0.05）. SSA inhibited the viability of A549 cells with the half maximal inhibitory concentration （IC₅₀） being 34.9 μmol·L^-1， and also suppressed the viability of A549/DDP cells in a concentration-dependent manner. Since the inhibition rate of 20 μmol/L SSA against A549/DDP cells was less than 10%， the reversal concentration was set at 20 μmol/L. Flow cytometry revealed that compared with the control， DDP alone increased the apoptosis rate of A549/DDP cells （<italic>P</italic><0.05）， stimulated the accumulation of intracellular ROS （<italic>P</italic><0.05）， down-regulated the mRNA expression levels of C-myc and Bcl-2 in A549/DDP cells， up-regulated Caspase-3 mRNA expression， and reduced the transcriptional activity of <italic>β</italic>-catenin （<italic>P</italic><0.05）. Compared with the DDP group， the SSA+DDP group exhibited obviously increased apoptosis of A549/DDP cells， enhanced accumulation of intracellular ROS， down-regulated C-myc and Bcl-2 mRNA expression， up-regulated Caspase-3 mRNA expression （<italic>P</italic><0.05）， and weakened <italic>β</italic>-catenin transcription （<italic>P</italic><0.05）. DDP combined with SSA better decreased the <italic>β</italic>-catenin protein expression in contrast to that of control or DDP （<italic>P</italic><0.05）. Conclusions:SSA enhances the sensitivity of A549/DDP cells to DDP possibly by inhibiting the activation of Wnt/<italic>β</italic>-catenin pathway.

Caspase-4 is essential for saikosaponin a-induced apoptosis acting upstream of caspase-2 and γ-H2AX in colon cancer cells.

Saikosaponin a (SSa), a bioactive phytochemical from Bupleurum, triggers sequential caspase-2 and caspase-8 activation, and thereby induces caspase-mediated apoptosis in human colon carcinoma (HCC) cells. However, the upstream mechanism of caspase-2 activation remains unknown. Therefore, we investigated the signaling mechanisms underlying SSa-induced caspase activation and apoptosis in HCC cells. SSa treatment triggered marked antitumor effects, especially in HCC cells, in a cell culture model and a mouse xenograft model. SSa also induced the activation of several endoplasmic reticulum (ER) stress signals. Specifically, caspase-4, a critical regulator of ER stress-induced apoptosis, was activated significantly after SSa treatment. Mechanistically, selective inhibition of caspase-4 suppressed SSa-induced apoptosis, colony inhibition, and the activation of caspase-3, -8, and -2, but not vice versa. Consistent with the important role of caspase-2 in the DNA damage response, SSa induced DNA damage, as evidenced by a cytokinesis-block micronucleus assay, single-cell gel electrophoresis, and an increase in the levels of γ-H2AX, a DNA damage marker. Moreover, inhibition of caspase-4 activation inhibited SSa-induced histone H2AX phosphorylation. Taken together, these results suggest that caspase-4 is an upstream regulator of SSa-induced DNA damage and caspase activation in HCC cells. Given that SSa-induced apoptosis appeared to be specific to certain cell types including HCC cells, SSa may be a promising cancer therapy agent in certain types of cancer.