Heying Pei

Millepachine, a novel chalcone, induces G2/M arrest by inhibiting CDK1 activity and causing apoptosis via ROS-mitochondrial apoptotic pathway in human hepatocarcinoma cells in vitro and in vivo

In this study, we reported millepachine (MIL), a novel chalcone compound for the first time isolated from Millettia pachycarpa Benth (Leguminosae), induced cell cycle arrest and apoptosis in human hepatocarcinoma cells in vitro and in vivo. In in vitro screening experiments, MIL showed strong antiproliferation activity in several human cancer cell lines, especially in HepG2 cells with an IC50 of 1.51 µM. Therefore, we chose HepG2 and SK-HEP-1 cells to study MILs antitumor mechanism. Flow cytometry showed that MIL induced a G2/M arrest and apoptosis in a dose-dependent manner. Western blot demonstrated that MIL-induced G2/M arrest was correlated with the inhibition of cyclin-dependent kinase 1 activity, including a remarkable decrease in cell division cycle (cdc) 2 synthesis, the accumulation of phosphorylated-Thr14 and decrease of phosphorylation at Thr161 of cdc2. This effect was associated with the downregulation of cdc25C and upmodulation of checkpoint kinase 2 in response to DNA damage. MIL also activated caspase 9 and caspase 3, and significantly increased the ratio of Bax/Bcl-2 and stimulated the release of cytochrome c into cytosol, suggesting MIL induced apoptosis via mitochondrial apoptotic pathway. Associated with those effects, MIL also induced the generation of reactive oxygen species. In HepG2 tumor-bearing mice models, MIL remarkably and dose dependently inhibited tumor growth. Treatment of mice with MIL (20mg/kg intravenous [i.v.]) caused more than 65% tumor inhibition without cardiac damage compared with 47.57% tumor reduction by 5mg/kg i.v. doxorubicin with significant cardiac damage. These effects suggested that MIL and its easily modified structural derivative might be a potential lead compound for antitumor drug.

Truncated bFGF-mediated cationic liposomal paclitaxel for tumor-targeted drug delivery: Improved pharmacokinetics and biodistribution in tumor-bearing mice†

Fibroblast growth factor receptors, overexpressed on the surface of a variety of tumor cells and on tumor neovasculature, are potential targets for tumor- and vascular-targeting therapy. The purpose of our present study was to compare the pharmacokinetics and tissue distribution of a novel truncated basic fibroblast growth factor peptide-mediated cationic liposomal paclitaxel (tbFGF-LPs-PTX) with free paclitaxel (F-PTX) and cationic liposomal paclitaxel (LPs-PTX) in tumor-bearing mice. In plasma, tbFGF-LPs-PTX exhibited similar pharmacokinetic properties to LPs-PTX but different with F-PTX. The AUC(0→∞) values were about 1.38-fold and one fold compared with those of F-PTX and LPs-PTX, respectively. TbFGF-LPs-PTX showed significant difference in biodistribution characteristics and displayed high accumulation in tumor and spleen in comparison with other two formulations. The AUC(0→∞) values achieved, respectively, about 7.17-fold and 2.60-fold accumulation in tumor, and about 4.28-fold and 2.25-fold increase in spleen compared with those of F-PTX and LPs-PTX. In contrast, the AUC(0→∞) values were much lower in liver compared with those of F-PTX and LPs-PTX. Our data indicated that tbFGF-LPs-PTX significantly increased the accumulation in tumor and prolonged the retention time, suggesting that it was a promise tumor-targeted delivery system and might provide a new treatment strategy for tumors.

Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells.

To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting.

Separation of flavonoids from Millettia griffithii with high‐performance counter‐current chromatography guided by anti‐inflammatory activity

Millettia griffithii is a unique Chinese plant located in the southern part of Yunnan Province. Up to now, there is no report about its phytochemical or related bioactivity research. In our previous study, the n-hexane crude extract of Millettia griffithii revealed significant anti-inflammatory activity at 100 μg/mL, inspiring us to explore the anti-inflammatory constituents. Four fractions (I, II, III, and A) were fractionated from n-hexane crude extract by high-performance counter-current chromatography with solvent system composed of n-hexane/ethyl acetate/methanol/water (8:9:8:9, v/v) and then were investigated for the potent anti-inflammatory activity. Fraction A, with the most potent inhibitory activity was further separated to give another four fractions (IV, V, VI, and B) with solvent system composed of n-hexane/ethyl acetate/methanol/water (8:4:8:4, v/v). Compound V and fraction B exhibited remarkable anti-inflammatory activity with nitric oxide inhibitory rate of 80 and 65%, which was worth further fractionation. Then, three fractions (VII, VIII, and IX) were separated from fraction B with a solvent system composed of n-hexane/ethyl acetate/methanol/water (8:1:8:1, v/v), with compound VIII demonstrating the most potent inhibitory activity (80%). Finally, the IC50 values of compound V and VIII were tested as 38.2 and 14.9 μM. The structures were identified by electrospray ionization mass spectrometry and(1)H and (13)C NMR spectroscopy.

Gambogic acid exhibits anti-psoriatic efficacy through inhibition of angiogenesis and inflammation

BACKGROUND Psoriasis is a chronic T cell-mediated inflammatory skin disease. Studies have shown that angiogenesis plays an important role in the pathogenesis of psoriasis. Studies have also indicated that Gambogic acid (GA) inhibits angiogenesis and may be a viable drug candidate in anti-angiogenesis therapies. OBJECTIVE The aim of this study was to investigate the anti-psoriatic effect of GA and the possible mechanisms. METHODS MTT test on HaCaT cells and immunofluorescence on HUVEC cells were processed. An O/W cream of GA was prepared and topically applied to the ears of K14-VEGF transgenic mice and psoriasis-like guinea-pigs, and the tail skin of Balb/C mice independently. Furthermore, hematoxylin-eosin staining of tissues from three models and immunohistochemistry staining of ear samples from K14-VEGF mice were performed. RESULTS In vitro, GA inhibited proliferation of HaCaTs and TNF-α-induced activation of NF-κB in HUVECs. In vivo, animals treated with GA showed significant morphological and histological improvements. Immunohistochemical analysis of K14-VEGF transgenic mice revealed that hyperplastic and inflamed vessels were suppressed with GA treatment. The expression of adhesion molecules such as ICAM-1 and E-selectin was significantly decreased. GA inhibited angiogenesis and the expression of VEGFR2 and p-VEGFR2. T lymphocyte infiltration and the expression of IL-17 and IL-22 were also reduced by GA treatment. CONCLUSION Our results suggest that GA has anti-psoriatic efficacy through inhibition of angiogenesis and inflammation. Therefore, GA is attractive and offers future potential for application in patients with psoriasis.

Synthesis and Biological Evaluation of 5-Benzylidenepyrimidine-2,4,6(1H,3H,5H)-trione Derivatives for the Treatment of Obesity-Related Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), one of chronic liver diseases, seems to be rising as the obesity epidemic continues. In this study, 54 novel (thio)barbituric acid derivatives have been synthesized and evaluated for pharmacological activity. 7h exhibited potent glucose-lowering effects on insulin-resistant HepG2 cells and regulated adiponectin and leptin expression in 3T3-L1 adipocytes. Oral administration of 7h at 25 mg kg(-1) day(-1) for 4 weeks improved the progression of high fat diet-induced NAFLD by reducing the weight of body, liver, and fat, as well as modulating serum levels of fasting glucose, insulin, triglycerides, LDL-c, ALT, adiponectin and hepatic contents of triglycerides, total cholesterol. H&E stainings revealed that 7h blocked fat deposition in liver and the increase of adipocyte number and size in adipose tissues from NAFLD. Furthermore, treatment with 7h alleviated the obese clinical symptoms, recovered serum biomarkers to appropriate ranges, and improved glucose tolerance by OGTT and IGTT in DIO mice.

Synthesis and Biological Evaluation of Novel Urea- and Guanidine-Based Derivatives for the Treatment of Obesity-Related Hepatic Steatosis

Leptin, the product of the obese gene, is an adipocyte-secreted protein hormone playing a key role in the progression of obesity and hepatic steatosis. In this study, 28 novel (thio)urea and guanidine-based analogues have been synthesized and N-(1-(4-(3-(2-chloroethyl)ureido)benzyl)piperidin-4-yl)-3-(trifluoromethyl) benzamide (7i) was found to be a potent regulator of leptin expression in 3T3-L1 adipocytes. Treatment with 7i at a dose of 50 mg/kg/day for 35 days reduced the body weight and liver weight of diet-induced obesity mice by 13.5% and 18.4%, respectively, while also improving the serum levels of triglyceride, total cholesterol, leptin, adiponectin, LDL-c, HDL-c. Hematoxylin-eosin (H&E) and Oil Red O staining also confirmed that 7i ameliorated fat deposition in liver tissue and restricted the size of adipocytes in obesity-related fatty liver disease.

Non-toxic dose of liposomal honokiol suppresses metastasis of hepatocellular carcinoma through destabilizing EGFR and inhibiting the downstream pathways

At present, there is no specific anti-metastasis drug in HCC treatment. Drugs used for primary HCC tumors and tumor metastasis are very similar, among which cytotoxic drugs are prevalent, such as cisplatin, doxorubicin and 5-FU. The EGFR pathway plays an important role in promoting hepatocellular carcinoma (HCC) metastasis. Hence, development of non-toxic anti-metastasis drugs, such as EGFR or downstream pathways inhibitors, is of great importance. In our present study, we found non-toxic dose of liposomal honokiol (LH) could inhibit the HCC metastasis by destabilizing EGFR and inhibiting the downstream pathways. Non-toxic dose of LH significantly inhibited the motility, migration and lamellipodia formation of HepG2 cells in vitro and decreased extravasation of HepG2 cells in a novel metastasis model of transgenic zebrafish. In two lung metastasis models (HepG2 and B16F10) and a spontaneous metastasis model of HepG2 cells, LH remarkably inhibited pulmonary metastasis and regional lymph nodes metastasis without obvious toxicity. Further study showed that destabilizing EGFR and inhibiting the downstream pathways were the main mechanisms of non-toxic dose of LH on metastasis inhibition. Our results provide the preclinical rationale and the underlying mechanisms of LH to suppress HCC metastasis, implicating LH as a potential therapeutic agent to block HCC metastasis without severe side effects.

Synthesis, Biological Evaluation and Molecular Docking of (R)‐2‐((8‐(3‐aminopiperidin‐1‐yl)‐3‐methyl‐7‐(3‐methylbut‐2‐en‐1‐yl)‐2,6‐dioxo‐2,3,6,7‐tetrahydro‐1H‐purin‐1‐yl)methyl)benzonitrile as Dipeptidyl Peptidase IV Inhibitors

Type 2 diabetes (T2D) is classified as a major metabolic disorder, which has affected approximately 194 million people worldwide. DPP‐IV inhibitors as a new therapy have shown several advantages over traditional antidiabetic drugs. Based on the similar binding modes of Alogliptin and Linagliptin, molecular operation was conducted via combining pharmacophore hybridization with structural optimization between the two market drugs and racemic compounds 40 and 43 were reported as DPP‐IV inhibitors in our previous studies. But the majority of DPP‐IV inhibitors have developed into a small molecule with certain conformation; in this study, we described the synthesis, biological evaluation, and molecular docking of corresponding enantiomers of compounds 40 and 43. The most potent inhibitor is (R)‐40 (IC50 = 23.5 nm, F = 74.67%, T1/2 = 4 h), which exhibited moderate antihyperglycemic activity as compared to the standard antidiabetic drug Linagliptin in OGTT. In addition, compound (R)‐40 effectively improved the pathological state of DIO mice. Molecular docking studies clarified the favorable binding affinity between compound (R)‐40 and DPP‐IV active site. Thus, compound (R)‐40 would be entitled to further development as a drug candidate on the basis of the suitable pharmacokinetic (PK) and desirable pharmacodynamic (PD) profiles.

Synthesis, Activity, and Docking Study of Novel Phenylthiazole‐Carboxamido Acid Derivatives as FFA2 Agonists

Free fatty acid receptor 2 (FFA2), also known as GPR43, is activated by short‐chain fatty acids (SCFAs) that are mainly produced by the gut microbiota through the fermentation of undigested carbohydrates and dietary fibers. FFA2 currently appears to be a potential target in the management of obesity, diabetes, inflammatory diseases, and cancer. In the study, a series of novel phenylthiazole‐carboxamido acid derivatives has been synthesized and evaluated as potential orthosteric FFA2 ligands for the study of structure–activity relationships. Compound 6e was found to exhibit the twofold potent agonistic activity in the stable hFFA2‐transfected CHO‐K1 cells (EC50 = 23.1 μm) as that of positive control propionate (EC50 = 43.3 μm). We also reported the results of mutagenesis studies based on the crystal structure of hFFA1 bound to TAK‐875 at 2.3 Å resolution to identify important residues for orthosteric agonist 6e inducing FFA2 activation.