Understanding dihydro-β-agarofuran sesquiterpenes from Tripterygium hypoglaucum as the modulators of multi-drug resistance in HepG2/Adr cells

Identification of Scutebarbatine B metabolites in rats using UHPLC-Q-Orbitrap-MS/MS and exploration of its mechanism of reversal multidrug resistance in breast cancer by network pharmacology and molecular docking studies

Scutebarbatine B (SBT-B) is a neo-clerodane diterpenic compound isolated from Scutellaria barbata D. Don (S. barbata), which has been reported to exhibit inhibitory P-glycoprotein (P-gp) property in MCF-7/ADR cells. However, its metabolism and molecular mechanism of reversal multidrug resistance (MDR) in breast cancer remains unclear. This study investigated the metabolite profile of SBT-B in rats by UHPLC-Q-Orbitrap-MS/MS, and explored its mechanism of reversal MDR through network pharmacology and molecular docking studies. A total of 16 Phase I metabolites and 2 Phase II metabolites were identified, and 18 metabolites were all newly discovered metabolites as novel compounds. The metabolic pathway of SBT-B mainly includes oxidization, reduction, hydrolysis, acetylation and glycination. Meanwhile, network pharmacology analyses showed that SBT-B mainly regulated p27 phosphorylation during cell cycle progression, p53 signaling pathway, influence of Ras and Rho proteins on G1 to S Transition. Molecular docking studies revealed that SBT-B exhibits the potential to inhibit P-gp expression by selectively binding to GLN721 and ALA981 residue sites at the interface of P-gp. In addition, SBT-B exhibits moderate binding affinity with CDK2 and E2F1. This study illustrated the major metabolic pathways of SBT-B in vivo, clarified detailed information on SBT-B metabolites in rats, and uncovered the potential mechanism of SBT-B reversal MDR in breast cancer, providing new insights for the development of P-gp inhibitors.

A review on phytochemicals as combating weapon for multidrug resistance in cancer

One can recognize multidrug resistance (MDR) and residue as a biggest difficulty in cancer specialist. Chemotherapy-resistant cancer may be successfully treated by combining MDR-reversing phytochemicals with anticancer drugs. Though, clinical application of phytochemicals either alone or in conjunction with chemotherapy is still in its early stages or requires more research to determine their safety and efficacy. In this review we highlighted topics related to MDR in cancer, including an introduction to subject, mechanism of action of efflux pump, specific proteins involved in drug resistance, altered drug targets, increased drug metabolism, and potential role of phytochemicals in overcoming drug resistance.

Celastrus paniculatus seed extract exhibits neuroprotective effects against MPP+‑induced apoptotic cell death via GSK‑3β in a Parkinson's disease model

Parkinson's disease (PD) is a common neurodegenerative disease induced by the death of dopaminergic neurons. Seed oil of Celastrus paniculatus (CP) Willd. has protective and antioxidant properties; however, to the best of our knowledge, no studies have analyzed the neuroprotective effect of CP seeds on PD. The present study aimed to investigate the neuroprotective effects and mechanism of CP seed extract (CPSE) using an in vitro 1-methyl-4-phenylpyridinium ion (MPP+)-induced PD model. The effect of CPSE on the expression levels of apoptotic marker proteins, such as Bcl-2 and its upstream pathway protein, glycogen synthase kinase-3β (GSK-3β), was investigated in human neuroblastoma SH-SY5Y cells. The effect of CPSE on the viability of SH-SY5Y cells was evaluated using MTT assay. To investigate the potential neuroprotective effect of CPSE, SH-SY5Y cells were treated with MPP+ to induce PD-associated cytotoxicity. SH-SY5Y cells were treated with 2 mM MPP+ before or after CPSE treatment to determine the protective effect of CPSE against MPP+-induced neurotoxicity using MTT, WST-1 and lactate dehydrogenase assays. Moreover, it was investigated whether CPSE could promote survival signals by regulating the protein expression levels of apoptotic markers (Bcl-2 and GSK-3β) using western blotting. High concentrations and prolonged treatment of CPSE did not have any adverse effect on SH-SY5Y cell viability. Furthermore, MPP+-induced dopaminergic neuron damage was ameliorated by CPSE treatment. CPSE also showed anti-apoptotic activity by reversing the inhibitory effects of MPP+ on Bcl-2 expression. Moreover, CPSE abolished MPP+-induced decreases in phosphorylated-GSK-3β (Ser9) expression. Taken together, the present findings suggested that CPSE may exert a neuroprotective effect in PD.

Tripterygium glycosides sensitizes cisplatin chemotherapeutic potency by modulating gut microbiota in epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is a fatal gynecological malignancy with limited therapeutic options. Previous research has demonstrated that Tripterygium glycosides (GTW) can enhance effectiveness of cisplatin (DDP) chemotherapy against EOC. However, the underlying mechanism of GTW alleviating EOC still remains unclear. In this article, an ID8 cell-derived xenograft mouse model was established to evaluate the anti-tumor efficacy of GTW combined with DDP. Consistent with previous findings, the results suggested that GTW combined with DDP can exhibit a stronger tumor suppressive effect than DDP alone. Additionally, GTW was found can further exert gastrointestinal protection against DDP by reducing pathological damage on colon tissue. Secondly, to verify whether gut microbiota play an instrumental role in GTW's anticancer effect, we treated mice models with antibiotic to eliminate gut microbiota. And our experimental results indicated that all drug groups showed a weaker tumor suppressive effect and more severe gastrointestinal damage post antibiotic supplement. At genus level, the relative abundance of Lactobacillus was dramatically diminished by the antibiotic treatment, while combined treatment of GTW and DDP can significantly restore the level. Moreover, we performed Lactobacillus acidophilus transplantation and healthy mice fecal microbiota transplantation experiments to further investigate the link between the anticancer effect of GTW and gut microbiota. Our results suggested that both cisplatin-sensitizing and intestinal barrier-protecting effects of GTW can be recovered to a different extent. In conclusion, our results indicated that GTW is a promising chemosensitization and intestinal barrier repair drug for EOC, and the potential mechanism may corelate with the restoration of the compromised intestinal microbial balance.

Gansui-Banxia Decoction extraction inhibits MDSCs accumulation via AKT /STAT3/ERK signaling pathways to regulate antitumor immunity in C57bl/6 mice

BACKGROUND

Gansui-Banxia Decoction (GSBXD) is a classic formula of traditional Chinese medical (TCM) sage Zhang Zhongjing to treat stagnation of evil heat and obstruction of qi. At present GSBXD is wildly used to treat cancerous ascites, pleural effusion, peritoneal effusion, pericardial effusion, cranial cavity effusion and several types of cancers, such as hepatocellular carcinoma (HCC) and esophageal cancer. Myeloid-derived suppressor cells (MDSCs) are a kind of immature and heterogeneous cells which can suppress lymphocytes activation by forming a suppressive environment. MDSCs accumulation in peripheral blood and tumors are closely related to the cancer stage and low survival rate of clinical patients. The antitumor immune effect of GSBXD has not received widespread attention.

PURPOSE

To investigate the effects of GSBXD on MDSCs accumulation and the mediators including AKT/STAT3/ERK signaling pathways.

METHODS

The chemical components of GSBXD were analyzed by UHPLC-MS, and the putative pathways of GSBXD based on Network pharmacology were predicted. Mice were vaccinated with Hepatoma 22 (H22) to establish tumor growth model, which were then administrated with GSBXD ethanol extraction (0.49 mg/kg/day, 1.75 mg/kg/day), sorafenib (60 mg/kg) or saline for 14 days. The cell morphology was evaluated by hematoxylin and eosin (H&E) staining, and immunity cells were determined through flowcytometry analysis. The levels of cytokines production in blood were evaluated by using ELISA kits. STAT3, ERK and AKT/mTOR signaling transduction associated proteins were determined by Western blot.

RESULTS

GSBXD could inhibit tumor growth and splenomegaly in H22 tumor model mice. Importantly, GSBXD reduced MDSCs accumulation and differentiation, and inhibited proliferation of F4/80⁺ CD11b⁺ macrophages and apoptosis of T cells and B cells, and increased the percentage of CD 3^- NK1.1⁺ NK cells. To better understand the active component of GSBXD, the ethanol-extraction powdered GSBXD was prepared and analyzed by UHPLC-MS. Combined with these main chemical compounds, we predicted that the anti-tumor effect of GSBXD mainly mediated PI3K-AKT and RAS-MAPK signal pathways based on Network Pharmacology. Western blot analysis of tumor tissues and MDSCs cells demonstrated that phosphorylation of AKT, ERK and STAT3 were significantly reduced, specially the activation of ERK. The levels of IL-1β and IFN-γ were significantly decreased by ELISA analysis.

CONCLUSION

GSBXD exhibited antitumor immune activity by reducing the accumulation of MDSCs in vivo, which is possible via down-regulation of AKT/STAT3/ERK signaling pathway and suppression of IL-1β and IFN-γ.

Tripterygium hypoglaucum (Lévl.) Hutch and Its Main Bioactive Components: Recent Advances in Pharmacological Activity, Pharmacokinetics and Potential Toxicity

Tripterygium hypoglaucum (Lévl.) Hutch (THH) is believed to play an important role in health care and disease treatment according to traditional Chinese medicine. Moreover, it is also the representative of medicine with both significant efficacy and potential toxicity. This characteristic causes THH hard for embracing and fearing. In order to verify its prospect for clinic, a wide variety of studies were carried out in the most recent years. However, there has not been any review about THH yet. Therefore, this review summarized its characteristic of components, pharmacological effect, pharmacokinetics and toxicity to comprehensively shed light on the potential clinical application. More than 120 secondary metabolites including terpenoids, alkaloids, glycosides, sugars, organic acids, oleanolic acid, polysaccharides and other components were found in THH based on phytochemical research. All these components might be the pharmacological bases for immunosuppression, anti-inflammatory and anti-tumour effect. In addition, recent studies found that THH and its bioactive compounds also demonstrated remarkable effect on obesity, insulin resistance, fertility and infection of virus. The main mechanism seemed to be closely related to regulation the balance of immune, inflammation, apoptosis and so on in various disease. Furthermore, the study of pharmacokinetics revealed quick elimination of the main component triptolide. The feature of celastrol was also investigated by several models. Finally, the side effect of THH was thought to be the key for its limitation in clinical application. A series of reports indicated that multiple organs or systems including liver, kidney and genital system were involved in the toxicity. Its potential serious problem in liver was paid specific attention in recent years. In summary, considering the significant effect and potential toxicity of THH as well as its components, the combined medication to inhibit the toxicity, maintain effect might be a promising method for clinical conversion. Modern advanced technology such as structure optimization might be another way to reach the efficacy and safety. Thus, THH is still a crucial plant which remains for further investigation.

Phytochemicals reverse P-glycoprotein mediated multidrug resistance via signal transduction pathways

P-glycoprotein, encoded by ATP-binding cassette transporters B1 gene (ABCB1), renders multidrug resistance (MDR) during cancer chemotherapy. Several synthetic small molecule inhibitors affect P-glycoprotein (P-gp) transport function in MDR tumor cells. However, inhibition of P-gp transport function adversely accumulates chemotherapeutic drugs in non-target normal tissues. Moreover, most small-molecule P-gp inhibitors failed in the clinical trials due to the low therapeutic window at the maximum tolerated dose. Therefore, downregulation of ABCB1-gene expression (P-gp) in tumor tissues seems to be a novel approach rather than inhibiting its transport function for the reversal of multidrug resistance (MDR). Several plant-derived phytochemicals modulate various signal transduction pathways and inhibit translocation of transcription factors, thereby reverses P-gp mediated MDR in tumor cells. Therefore, phytochemicals may be considered an alternative to synthetic small molecule P-gp inhibitors for the reversal of MDR in cancer cells. This review discussed the role of natural phytochemicals that modulate ABCB1 expression through various signal transduction pathways in MDR cancer cells. Therefore, modulating the cell signaling pathways by phytochemicals might play crucial roles in modulating ABCB1 gene expression and the reversal of MDR.