[Advances of tumor targeting peptides drug delivery system with pH-sensitive activities].

The pH-sensitive peptides drug delivery systems, which target to acidic extracellular environment of tumor tissue, have many advantages in drug delivery. They exhibit a high specificity to tumor and low cytotoxicity, which significantly increase the efficacy of traditional anti-cancer drugs. In recent years the systems have received a great attention. The pH-sensitive peptides drug delivery systems can be divided into five types according to the difference in pH-responsive mechanism,type of peptides and carrier materials. This paper summarizes the recent progresses in the field with a focus on the five types of pH-sensitive peptides in drug delivery systems. This may provide a guideline to design and application of tumor targeting drugs.

[Carboxyl nanodiamond as intracellular transporters of anticancer drug--podophyllotoxin].

The purpose of this study is to investigate the intracellular transporters effect and the cytotoxicity of carboxyl nanodiamond (CND) - podophyllotoxin (PPT). Nanodiamond (ND) was treated with mixed carboxylic acid and finally got 64 nm CND by centrifugation, and then it was reacted with PPT to form CND-PPT. UV spectrophotometry was used to calculate the content of PPT in CND-PPT, the particle size distribution and zeta potential were measured by Dynamic laser scattering instrument. CND, PPT, CND-PPT and CND + PPT (physical mixture of CND and PPT) were characterized by Fourier transform infrared spectroscopy, at the same time, thermal analysis and element analysis were used to estimate the content of the PPT in CND-PPT. The affect of CND, PPT, CND-PPT on HeLa cell was measured with MTT assay. The results showed that content of PPT combined with CND accounted for about 10%. MTT assay showed that CND has low cytotoxicity and CND-PPT can increase the water soluble of PPT. As a conclusion, CND as a hydrophilic pharmaceutical carrier combined with PPT is able to increase the water solubility of PPT, at low concentration, CND-PPT can enhance the antitumor activity in comparison with PPT, so CND can be used as a potential anticancer drug carrier.

[Advances in parallel artificial membrane permeability assay and its applications].

With the development of drug discovery, more and more candidate compounds need to be studied. Methods that can screen compound rapidly received significant attention. Parallel artificial membrane permeability assay (PAMPA) as a powerful tool has been applied to drug studies. It uses an artificial lipid membrane to mimic the barrier for drug permeability studies. This article introduces the establishment and characteristics of PAMPA, as well as its applications in screening compounds. It can be used as models (e.g. predicting the ability of compound in gastro-intestinal absorption, blood-brain barrier transportation and skin penetration) by changing the component of artificial lipid membrane. PAMPA has advantages in high throughput selection of valuable compound with low cost, versatile, low dose, and good reproducibility.

Hepatoprotective effect of total flavonoids from Glycyrrhiza uralensis Fisch in liver injury mice.

This work aimed to investigate the hepatoprotective effect of total flavonoids from Glycyrrhiza uralensis. The main compounds in licorice total flavonoids (LTF) were isolated from Glycyrrhiza uralensis and their total content in LTF were more than 60%. Hepatoprotective effects of LTF were investigated in three kinds of hepatic injury mice model induced by high-fat emulsion, Chinese liquor and tetrachloromethane. Serum ALT, AST and ALP levels and hepatic MDA, TG, cholesterol, and hydroxyproline of hepatic injury mice were reduced by LTF. Simultaneously, hepatic SOD and glutathione were increased by LTF. These results suggested that LTF can repair liver tissue and reduce hepatic injury via alleviating inflammation, improving antioxidant enzyme activity and reducing oxidative stress in liver tissue and it may be a valuable natural source of hepatoprotective activity.

Anti-atherosclerotic effect of Fermentum Rubrum and Gynostemma pentaphyllum mixture in high-fat emulsion- and vitamin D3-induced atherosclerotic rats.

BACKGROUND: The mixture of Hongqu and gypenosides (HG) is composed of Fermentum Rubrum (Hongqu, in Chinese) and total saponins of Gynostemma pentaphyllum (Thunb.) Makino (Jiaogulan, in Chinese) in a 3.6:1 weight ratio. Both Hongqu and Jiaogulan are considered valuable traditional Chinese medicines (TCMs); they have been commonly used in China for the treatment of hyperlipidemia and related diseases for centuries. The aim of the current study was assess the anti-atherosclerotic effect of HG. METHODS: Sixty-four Wistar rats were randomly divided into eight groups: normal, model, positive control (simvastatin, 1 mg/kg), Hongqu-treated (72 mg/kg), gypenoside (total saponin)-treated (20 mg/kg), and three doses HG-treated (50, 100, and 200 mg/kg). All of the rats were fed a basal diet. Additionally, the model group rats were intragastrically administered a high-fat emulsion and intraperitoneally injected with vitamin D3. The serum lipid profiles, oxidative stress, inflammatory cytokine, and hepatic antioxidant levels were then determined. Furthermore, the liver histopathology and arterial tissue were analyzed, and the expression of hyperlipidemia- and atherosclerosis (AS)-related genes was measured using reverse transcription-polymerase chain reaction. RESULTS: The AS rat model was established after 80 days. Compared to the model group, the HG-treated groups showed an obvious improvement in the serum lipid profiles, oxidative stress, and inflammatory cytokine levels, and showed markedly increased hepatic total antioxidant capacity. Moreover, the expression of genes related to lipid synthesis and inflammation reduced and that of the genes related to lipid oxidation increased in the liver and arterial tissue, which also reflected an improved health condition. CONCLUSION: the anti-atherosclerotic effects of HG were superior to those of simvastatin, Hongqu, and the gypenosides. Therefore, HG may be a useful anti-atherosclerotic TCM preparation.

In vivo and in vitro anti-inflammatory effects of ethanol fraction from Periploca forrestii Schltr.

OBJECTIVE: To determine the anti-inflflammatory effects of an ethanol fraction of Periploca forrestii Schltr. (EFPF) and to investigate the potential mechanisms underlying in vivo and in vitro models. METHODS: The antiinflflammatory effects of EFPF were evaluated using the xylene-induced mouse ear edema and carrageenan-induced rat paw edema models in vivo. In vitro, RAW264.7 cells were exposed to 0-800 µg/mL EFPF and the cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Then cells were treated with different concentrations of EFPF (100-400 µg/mL) and stimulated with lipopolysaccharide (LPS, 1 µg/mL) for 24 h. The supernatant was analyzed for nitric oxide (NO) using the Griess reagent, and the levels of inflflammatory mediators and cytokines were determined using enzyme-linked immunosorbent assays for prostaglandin E2 (PGE2), tumor necrosis factor α (TNF-α), interleukin (IL) 6, and IL-10. The protein expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor κB (NF-κB), and mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK were examined by Western blot. RESULTS: Compared with the control group, EFPF signifificantly reduced mouse ear edema and rat paw edema rate (P<0.05 or P<0.01). Compared with the LPS group, EFPF signifificantly inhibited the LPS-stimulated production of NO, PGE2, TNF-α and IL-6 (P<0.05 or P<0.01), and increased the IL-10 production (P<0.05). EFPF also signifificantly inhibited LPS-induced protein expressions of iNOS and COX-2, suppressed the phosphorylation and degradation of inhibitor of NF-κB-α, decreased p65 level, and inhibited the phosphorylation of p38, ERK1/2 and JNK P<0.05 or P<0.01). CONCLUSION: EFPF exerted anti-inflflammatory effect by reducing protein expressions of iNOS and COX-2 and the production of the inflflammation factors, including TNF-α, IL-6, NO and PGE2, mainly through inhibition of LPS-mediated stimulation of NF-κB and MAPK signaling pathways.

[Studies on antitumor effects of podophyllotoxin nanoliposome].

OBJECTIVE: To compare the antitumor effects of the podophyllotoxin nanoliposome and the suspensions of podophyllotoxin in bearing-tumor mice. METHOD: The experimental mice were inoculated by suspension liquid of tumor cell in axillary region near the forelimb, 0.2 mL each. The mice had been randomly divided into 8 groups 24 h latter. The podophyllotoxin nanoliposome, suspension liquid of the podophyllotoxin, CX or NS was given to each group respectively. Except CX was given by celiac injection once, the other groups were injected every 4 days for three times. The mice were killed by hauling necks on the twelfth day after treatment, the tumor was weighed and the inhibitory rate was calculated. RESULT: When the dosage of podophyllotoxin nanoliposome and the suspensions of podophyllotoxin reached 5.0 mg x kg(-1), the rate of inhibiting tumor were 52.37% and 38.25% to the H22 liver cancer of mice respectively. CONCLUSION: Podophyllotoxin nanoliposome and the suspensions of podophyllotoxin have the effect in anti-liver cancer. And podophyllotoxin nanoliposome have stronger inhibitory rate compared with suspension liquid of the podophyllotoxin in same dose.

Quantification and bio-assay of α-glucosidase inhibitors from the roots of Glycyrrhiza uralensis Fisch.

This work aimed to investigate the α-glucosidase inhibitor from the roots of Glycyrrhiza uralensis Fisch. Seven flavonoids were isolated, and the total content of compounds 1-7 were more than 50% in Glycyrrhiza total flavones (GTF), and the content of compound 1 and 2 was abundant in GTF. The results of the α-glucosidase inhibitory activities indicated that compounds 1-6 and GTF respectively with the IC50 values of 31.303, 30.263, 23.363, 19.528, 10.854, 26.454 and 21.641 µg/mL exhibited the more potent activity than acarbose with the IC50 values of 38.995 µg/mL. These result suggested that Glycyrrhiza flavonoids may become a valid alternative of potential basis for new hypoglycaemic and antidiabetic agents.

Lipid-lowering, hepatoprotective, and atheroprotective effects of the mixture Hong-Qu and gypenosides in hyperlipidemia with NAFLD rats.

BACKGROUND: Hyperlipidemia and its complications are among the most harmful of diseases with a worldwide impact, which creates an urgent imperative to find safe and effective drugs for treatment. HG is mainly composed of two kinds of traditional Chinese medicines (TCM), Hong-Qu and gypenosides. Previously, the ingredients of the mixture mainly composed by Hong-Qu and gypenosides (HG) were widely used for purposes of lipid-lowering, antiatherosclerosis effects, and maintaining cardiovascular health in China. The purpose of this study was to determine whether HG provides any benefit to patients with hyperlipidemia. METHODS: Forty-eight adult male Sprague-Dawley rats with fatty liver disease were randomly divided into six groups: normal, model, two positive controls, and two doses of HG-treated groups. The normal rats were fed a basal diet, and the other rats were fed a high-fat diet. Thereafter, the serum lipid profiles, hepatic steatosis, cytokines, enzymes, and relevant mRNA of rats were analyzed in serum, aorta tissue or hepatic tissues, respectively. RESULTS: After 65 days of feeding the high-fat diet to rats, there were significantly disordered serum lipid profiles, elevated oxidative stress biomarkers, and decreased antiinflammatory cytokines in the serum levels. Additionally, aortic foam cell formation was increased. The gene expression levels including hydroxymethylglutaryl-CoA reductase (HMGR), peroxisome proliferator-activated receptor alpha (PPAR-α), sterol response element-binding protein-1c (SREBP-1c), fatty acid synthase (FAS), acetyl-CoA carboxylase-1 (ACC-1) and carnitine palmitoyl transferase-1(CPT-1) in hepatic tissue were also altered by a high-fat diet fed to Sprague-Dawley rats, and HG treatment significantly resolved and normalized these alterations. Moreover, HG not only caused a significant decrease in the lipid drops on the hepatic tissues, but also restored the antioxidant components. CONCLUSION: HG is beneficial for regulating the stability of blood lipids, has atheroprotective characteristics and may prevent nonalcoholic fatty liver disease (NAFLD), providing more than just a theoretical basis for drug research of cardiovascular disease (CVD) treatment.

Preparation of isoliquiritigenin-loaded nanostructured lipid carrier and the in vivo evaluation in tumor-bearing mice.

Isoliquiritigenin-loaded nanostructured lipid carrier (ISL-NLC) was constructed and characterized. In vivo antitumor efficacy and immuno-modulation effects of ISL-NLC were evaluated in sarcoma 180 (S180)-bearing and murine hepatoma 22 (H22)-bearing mice model through intraperitoneal (i.p.) administration. The ISL-NLC biodistribution was also investigated in H22-bearing mice. Results demonstrated that the ISL-NLC had a spherical shape with a mean size of (160.73 ± 6.08) nm and encapsulation efficiency of (96.74 ± 1.81)%. ISL released from the nanoparticles was in a sustained manner with an initial burst release. ISL-NLC significantly inhibit tumor growth at 10, 20 and 40 mg/kg levels, and inhibition rates were 75.70%, 82.27% and 83.90% in the S180-bearing mice and 71.49%, 81.11% and 85.62% in the H22-bearing mice, respectively. The biodistribution study showed that ISL concentration of ISL-NLC in tumor is higher 2.5-fold than ISL suspension. The elimination half-life (t1/2), area under the curve (AUC) and the mean residence times (MRTs) of the ISL-NLC was much longer than that of the ISL suspension. As a whole, anticancer effect of ISL encapsulated in NLC was superior to ISL in suspension on H22-bearing and S180-bearing mice at the same dose and was a dose-dependent way, and ISL-NLC improved immunity of ISL. It can be inferred that nanostructured lipid carriers are a promising carrier for cancer therapy using ISL.

Synthesis and antinociceptive effects of endomorphin-1 analogs with C-terminal linked by oligoarginine.

Endomorphins (EMs) cannot be delivered into the central nervous system (CNS) in sufficient quantity to elicit antinociception when given systemically because they are severely restricted by the blood-brain barrier (BBB). In the present study, we investigated herein a series of EM-1 analogs with C-terminal linked by oligoarginine in order to improve the brain delivery and antinociception after systemic administration. Indeed, all these analogs decreased the opioid receptor affinity and in vitro pharmacological activity. Moreover, analogs 4, 7-9 produced a less potent antinociceptive activity after intracerebroventricular (i.c.v.) administration, with the ED(50) values about 11- to 13-fold lower potencies than that of EM-1. Nevertheless, our results revealed that EM-1 failed to induce any significant antinociception at a dose of 50µmol/kg after subcutaneous (s.c.) administration, whereas equimolar dose of these four analogs produced a little low but significant antinociceptive effects. Naloxone (10nmol/kg, i.c.v.) significantly blocked the antinociceptive effects, indicating an opioid and central mechanism. These results demonstrated that C-terminal of EM-1 linked to oligoarginine improved the brain delivery, eliciting potent antinociception following peripheral administration.

In vitro and in vivo antitumor effects of novel actinomycin D analogs with amino acid substituted in the cyclic depsipeptides.

The actinomycin D (AMD) analogs in which the D-valine residues (the second amino acid residue in the cyclic depsipeptide of AMD) and the N-methyl-L-valine residues (the fifth amino acid residue in the cyclic depsipeptide of AMD) were replaced with D-Phe or l- and D-forms N-methylvalines, N-methylisoleucine, N-methylleucine, N-methylphenylalanine, N-methylalanine, and sarcosine were synthesized. The antimicrobial activity and cytotoxic activities of these compounds in vitro were investigated. The results showed that most D-valine substituted analogs had much lower antimicrobial activity and cytotoxic activities in vitro than AMD itself, but three N-methyl-L-valine substituted analogs had comparable or even more remarkable cytotoxic activities in vitro than AMD. Acute toxicities and antitumor effects of the N-methyl-L-valine substituted analogs in mice were also examined. The result showed that the acute toxicity of compound 4 L-methylleucine(5)-AMD analog is comparable to AMD itself and that of compound 3(L-Methylisoleucine(5)-AMD analog) is slightly more toxic, about 1.25-fold than AMD. However, the acute toxicity of compound 5 D-methylleucine5-AMD analog is about 2-fold lower than AMD. This suggested that the N-methyl-D-amino acid replacement in the cyclic ring might play a vital role in their decreased acute toxicities, and perhaps the N-methyl-D-leucine substituent is more favorable, though there may be a slight loss of antitumor activity. This finding may be helpful for the design and development of more potent antitumor agents together with low acute toxicity, and suggests that the N-methyl-D-leucine substituent has the potential to be used as antitumor drug lead.