Xinmai 'an extract enhances the efficacy of sildenafil in the treatment of pulmonary arterial hypertension via inhibiting MAPK signalling pathway.

CONTEXT: Xinmai 'an tablet has been used to improve myocardial blood supply. Recently, some compounds from its formula have shown that they can treat pulmonary arterial hypertension (PAH). OBJECTIVE: This study investigates the effects of Xinmai 'an extract (XMA) on PAH and further tests the co-therapeutic enhancement with sildenafil (SIL). MATERIALS AND METHODS: Pulmonary artery smooth muscle cells were subjected to stimulation with SIL (12.5 µM) and XMA (250 µg/mL) for 48 h. Sprague-Dawley rats were randomly grouped into eight groups (n = 8 per group): (I) control group received saline; (II) MCT group received MCT (60 mg/kg); (III) SIL-Low group received MCT + SIL at 10 mg/kg/day; (IV) SIL-high group received MCT + SIL at 30 mg/kg/day; (V) XMA-High group received MCT + XMA at 251.6 mg/kg/day; (VI) SIL (Low)+XMA (Low) group received SIL (10 mg/kg) + XMA at 62.9 mg/kg/day; (VII) SIL (Low)+XMA (Medium) group received SIL (10 mg/kg) + XMA at 125.8 mg/kg/day; (VIII) SIL (Low)+XMA (High) group received SIL (10 mg/kg) + XMA at 251.6 mg/kg/day. Both XMA and SIL were given by gavage and were maintained daily for 2 weeks. RESULTS: XMA could improve SIL's efficacy in the treatment of PAH by decreasing cell viability more effectively at non-cytotoxic concentrations (250 µg/mL) and reducing Right Ventricular Systolic Pressure (RVSP) in PAH rat. Potential mechanisms might at least in part be through activating the MAPK signalling pathway. DISCUSSION AND CONCLUSIONS: The combination of XMA and SIL can improve the efficacy of pulmonary hypertension and reduce the dosage of SIL.

[Preparation of evodiamine-glycyrrhizic acid micelles with glycyrrhizic acid as carrier and their anti-hepatic fibrosis activity].

This study aimed to prepare evodiamine-glycyrrhizic acid(EVO-GL) micelles to enhance the anti-hepatic fibrosis activity of evodiamine. Firstly, EVO-GL micelles were prepared with use of thin film dispersion method. With particle size, encapsulation efficiency, loading capacity of micelles and the solubility of evodiamine as the indexes, the effect of different factors on micelles was observed to screen the optimal preparation methods and process. Then the pharmaceutical properties and the therapeutic effects of EVO-GL micelles prepared by optimal process were evaluated on CCl_4-induced hepatic fibrosis. The results showed that the micelles prepared by the thin film dispersion method had an even size, with an average particle size of(130.80±12.40)nm, Zeta potential of(-41.61±3.12) mV, encapsulation efficiency of 91.23%±1.22%, drug loading of 8.42%±0.71%, high storage stability at 4 ℃ in 3 months, and slow in vitro release. Experimental results in the treatment of CCl_4-induced hepatic fibrosis in rats showed that EVO-GL micelles had a synergistic anti-hepatic fibrosis effect, which significantly reduced the liver function index of hepatic fibrosis rats. In conclusion, the EVO-GL micelles prepared with glycyrrhizic acid as a carrier would have a potential application prospect for the treatment of hepatic fibrosis.

Glycyrrhizin improved autophagy flux via HMGB1-dependent Akt/mTOR signaling pathway to prevent Doxorubicin-induced cardiotoxicity.

Doxorubicin (DOX) is one of the most effective and irreplaceable chemotherapeutic agents but its clinical use is limited due to its cardiotoxicity. Glycyrrhizin(GL) has been applied to liver disorders for long. However, little is known that if GL could be meaningful in attenuating cardiotoxicity. The aim of this study is to investigate the cardioprotective effects of GL in DOX-induced cardiotoxicity (DIC) and the underlying mechanism. Here, H9c2 cardiomyoblasts, Neonatal rat cardiomyocytes (NRCMs), and Rats were introduced as test models. A single dose of 20 mg/kg DOX (i.p.) was applied to induce acute cardiotoxicity in vivo, as reflected by growth inhibition, increased levels of AST and CK-MB, and reduction of SOD activity, while GL (25 or 50 mg/kg/d, 14 d, i.p.) could counteract these effects. Moreover, pre-incubation with GL (0.8 mM for 12 h) in H9c2 cells protected against DOX-induced cytotoxicity, oxidative stress and depolarization of mitochondrial membrane potential (MMP). Besides, Western blot analysis showed that DOX upregulated the expression of LC3 II and p62 whereas GL reversed that both in vitro and in vivo and improved the obstructed autophagy flux in DOX-treated H9c2 cells with an autophagy inhibitor Bafilomycin A1 (Baf A1, 50 nM, 2 h). It has been previously documented that High-mobility group box 1 (HMGB1) was involved in DIC. In our work, knockdown of HMGB1 significantly increased cell viability and LC3 II level in H9c2, suggesting HMGB1 was crucial in DOX-induced autophagy-triggering cell death. Intriguingly, GL is a direct inhibitor of HMGB1. We found that GL downregulated Akt/mTOR autophagy signaling pathway in DOX-treated H9c2 cells. More importantly, in non-silencing H9c2 cells (transfected with negative control siRNA) cells, the expression of phospho-Akt, phospho-mTOR, p62, and LC3 II was significantly decreased with GL pretreament compared to DOX alone. However, in H9c2/HMGB1－(transfected with HMGB1 siRNA) cells exposed to DOX, the expression of p-Akt, p-mTOR, p62, LC3 II had no statistical difference with or without GL, revealing that HMGB1 mediated the cardioprotective action of GL in DIC. Taken together, our findings demonstrate that improved autophagy flux via HMGB1-dependent Akt/mTOR signaling pathway might contribute to attenuate DIC and go a novel insight into the underlying mechanisms of GL's cardioprotective action. GL could be a potential candidate for the prevention of DIC.

[Bortezomib and obatoclax for dual blockade of protein degradation pathways show synergistic anti-tumor effect in human acute T lymphoblastic leukemia cells].

OBJECTIVE: To explore whether bortezomib and a Bcl-2 inhibitor exhibit synergistic anti-tumor effect in human acute T lymphoblastic leukemia cells. METHODS: MTT assay was used to determine the cytotoxicity of bortezomib in the absence or presence of Bcl-2 inhibitors (obatoclax, AT-101 and ABT-199) in Jurkat cells. The effects of drug treatment on the expression of Bcl-2 family proteins, LC3B, p62, ubiquitin, BiP/Grp78, p-JNK, p-p38 and CHOP proteins were examined by Western blotting. Flow cytometry was used to determine the effects of bortezomib and Bcl-2 inhibitors (obatoclax, AT-101 and ABT-199) on cell apoptosis. Quantitative real-time PCR was used to measure the mRNA expression levels of the key regulatory factors of unfolded protein reaction (UPR). A zebrafish xenograft model was used to study the anti-tumor effect of bortezomib, obatoclax and their combination in vivo. RESULTS: Bortezomib or Bcl-2 inhibitors alone inhibited the cell viability of Jurkat cells, but only obatoclax and bortezomib showed synergistic cytotoxicity and pro-apoptotic effect. Obatoclax, rather than AT-101 and ABT- 199, blocked autophagic flux in the cells evidenced by concomitant accumulation of LC3B-Ⅱ and p62. Both bortezomib and obatoclax alone caused accumulation of polyubiquinated proteins, and their combination showed a synergistic effect, which was consistent with their synergistic cytotoxicity. The dual blockade of proteasome and autophagy by the combination of bortezomib and obatoclax triggered unfolded protein response followed by cell apoptosis. Preventing UPS dysfunction by tauroursodeoxycholic acid (TUDCA) significantly attenuated the cytotoxicity and pro-apoptotic effect of bortezomib in combination with obatoclax. In zebrafish xenograft models, bortezomib combined with obatoclax significantly decreased tumor foci formation. CONCLUSIONS: Bortezomib and obatoclax for dual blockade of protein degradation pathways show synergistic anti-tumor effect in human acute T lymphoblastic leukemia cells.