A Nano Drug Delivery System Based on Angelica sinensis Polysaccharide for Combination of Chemotherapy and Immunotherapy.

Combination of chemotherapy and immunotherapy has been a promising strategy in cancer treatment. Polysaccharides from Angelica sinensis (AP), a well-known Chinese herbal medicine, have been proved to have good immunomodulatory activity. In the present study, an enzyme-sensitive tumor-targeting nano drug delivery system (AP-PP-DOX (doxorubicin), PP stood for peptide) was constructed. In this system, Angelica polysaccharides act as not only carriers to targeted delivery of drugs to tumor tissue but also effectors to improve tumor microenvironment and enhance immune function, resulting in synergistic antitumor effect with chemotherapy drugs. The structure of this conjugate was confirmed by FI-IR and 1H-NMR. The particle size and zeta potential of the nanoparticles were 129.00 ± 3.32 nm and -28.45 ± 0.22 mV, respectively. Doxorubicin (DOX) and AP could be quickly released from the AP-PP-DOX under the presence of matrix metalloproteinase 2 (MMP2). The released DOX showed good antitumor efficacy in vitro. The treatment of released AP moiety increased the expression of IL-2, while that of IL-10 was decreased, showing potential in restoring Th1/Th2 immune balance in tumor microenvironment. In a word, this drug delivery system, with specific tissue targeting and tumor microenvironment improvement, will open a new avenue for combination treatment of cancer.

CD13 is essential for inflammatory trafficking and infarct healing following permanent coronary artery occlusion in mice.

AIMS: To determine the role of CD13 as an adhesion molecule in trafficking of inflammatory cells to the site of injury in vivo and its function in wound healing following myocardial infarction induced by permanent coronary artery occlusion. METHODS AND RESULTS: Seven days post-permanent ligation, hearts from CD13 knockout (CD13(KO)) mice showed significant reductions in cardiac function, suggesting impaired healing in the absence of CD13. Mechanistically, CD13(KO) infarcts showed an increase in small, endothelial-lined luminal structures, but no increase in perfusion, arguing against an angiogenic defect in the absence of CD13. Cardiac myocytes of CD13(KO) mice showed normal basal contractile function, eliminating myocyte dysfunction as a mechanism of adverse remodelling. Conversely, immunohistochemical and flow cytometric analysis of CD13(KO) infarcts demonstrated a dramatic 65% reduction in infiltrating haematopoietic cells, including monocytes, macrophages, dendritic, and T cells, suggesting a critical role for CD13 adhesion in inflammatory trafficking. Accordingly, CD13(KO) infarcts also contained fewer myofibroblasts, consistent with attenuation of fibroblast differentiation resulting from the reduced inflammation, leading to adverse remodelling. CONCLUSION: In the ischaemic heart, while compensatory mechanisms apparently relieve potential angiogenic defects, CD13 is essential for proper trafficking of the inflammatory cells necessary to prime and sustain the reparative response, thus promoting optimal post-infarction healing.

Synthesis of a new pH-sensitive folate-doxorubicin conjugate and its antitumor activity in vitro.

Folate-aminocaproic acid-doxorubicin (FA-AMA-DOX) was synthesized and characterized by H NMR spectroscopy and mass spectrometry. Cytotoxicity and cellular uptake experiments were performed in KB and HepG2 cells, which express folic acid receptor, and the cell line A549, which does not express folic acid receptor. Cytotoxicity was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cellular uptake was monitored using fluorescence microscopy. The amount of DOX released from FA-AMA-DOX was much greater at pH 5.0 than that at pH 6.5 or 7.4. The cytotoxicity of FA-AMA-DOX toward KB and HepG2 cells was greater than that of DOX or AMA-DOX at the same concentrations, and cytotoxicity could be attenuated by FA in a dose-dependent manner. On the contrary, the cytotoxicity of FA-AMA-DOX and AMA-DOX toward A549 cells was lower than that of DOX at the same concentration, and cytotoxicity could not be reduced by FA. Compared with FA-AMA, FA-AMA-DOX increased the intracellular accumulation of DOX in KB cells. These results suggested that FA-AMA-DOX have suitable attributes for the active targeting of folate-receptor-positive tumor cells and for releasing the chemotherapeutic agent, DOX, in situ; it therefore has potential as a novel cancer therapeutic.

Pharmacokinetics of the analogs at C3 and C5 of m-nifedipine in beagle dogs.

The prototype 1,4-dihydropyridine (1,4-DHP) nifedipine, indicated for the management of hypertension and angina pectoris, has disadvantages including photodegradation and a short half-life. Several newer 1,4-DHPs, including m-nifedipine and its analogs at the C3, C5 position such as MN9201, MN9202 and MN9203, have been designed to offset these problems. The aim of this study was to investigate the pharmacokinetic characteristics of these derivatives to provide reference for their further evaluation and modification. Derivatives were intravenously bolus administered to beagle dogs. The drug concentration in the plasma was determined by the HPLC method. The pharmacokinetic parameters were calculated by the non-compartmental method. The analysis of variance (ANOVA) was used to compare the pharmacokinetic parameters of the derivatives. The results showed that the area under the curve from time zero to the last sampling time (AUC(0-t)) of m-nifedipine, MN9201, MN9202 and MN9203 was 45.1 +/- 13.6, 51.7 +/- 15.2, 70 +/- 16 and 62 +/- 12.4 micromol/l*min, respectively. The elimination half-life (t(1/2)) was 98 +/- 24, 129 +/- 55, 190 +/- 21 and 92 +/- 25 min, respectively. The t(1/2) of MN9202 was significantly longer than those of the others (p<0.05 or p<0.01). These results suggest that the length of the carbon chain at the C3 or C5 position in the derivatives had a marked effect on its metabolism, and M9202 is a promising new drug candidate worth further evaluation.

[Anti-oxidative effect of Angelica polysaccharide sulphate].

OBJECTIVE: To investigate the anti-oxidative effect of Angelica polysaccharide sulphate( APS). METHODS: The Hela cells were cultured conventionally. Then APS was added and cultured together in different concentration for 24h followed by a oxidative injury with H2O2 or UV irradiation. The anti-oxidative effects of APS were detected as follow: cell viability was measured by MTT assay; colorimetric analysis was used to determine SOD activity, GSH and MDA level in cytoplasm. RESULTS: Treatment of H2O2 or UV irradiation significantly decreased cell viability, GSH and SOD activity in cytoplasm,while increased MDA in cytoplasm. At the range of 0. 3 -100microg/ml, APS significantly increased cell viabilty, GSH and SOD activity,while decreased MDA in a dose dependent manner( P < 0. 05 or P <0.01). CONCLUSION: APS has anti-oxidative effect,which may be one of its anti-AIDS mechanisms.

[Effect of Angelica sinensis polysaccharide fraction AP-3 on IL-2 and IFN-gamma induction].

AIM: To investigate the effects of Angelica sinensis polysaccharide fraction AP-3 on IL-2 and IFN-gamma induction and its further immunomodulatory feature. METHODS: The percentage of CD4+ lymphocyte was detected by flow cytometric method, the production of IL-2 and IFN-gamma in cell culture supernatant were determined by ELISA, mRNA expressions of IL-2 and IFN-gamma cytokines were detected by RT-PCR. RESULTS: At the range of 0. 6 - 2 micromol x L(-1), AP-3 significantly enhanced the percentage of CD4+ lymphocytes in total splenocytes. At the range of 2 - 6 micromol x L(-1), the treatment of AP-3 augmented both productions of IL-2 in cell culture supernatant and cell IL-2 mRNA transcription level in a time and dose dependent manner. While in the case of IFN-gamma, AP-3 stimulated at early time after exposure but down-regulated thereafter. CONCLUSION: Angelica sinensis polysaccharide could regulate the immune response through upregulating IL-2, IFN-gamma expression and activating Th1 cell.

[Effects of Angelica sinensis polysaccharide on cell-mediated immunity].

AIM: To investigate the effects of Angelica sinensis polysaccharide (AP) on cell-mediated immunity. METHODS: The lymphocyte proliferation was tested by MTT colormetry; T lymphocyte fraction were separated with immune magnetic beads and the change of CD4(+) T lymphocyte percentage was detected by flow cytometry. RESULTS: In the range of 30-300 mg/L, the total AP and its three fractions, ie AP-0, AP-1, AP-2, AP-3, directly stimulated the proliferation of murine splenocytes, and AP-3 significantly enhanced the proliferation of lymphocytes in MLR and T lymphocytes. The percentage of CD4(+) T lymphocytes in total splenocytes was also enhanced by AP-3. CONCLUSION: AP can promote the cell-mediated immunity with T lymphocytes as one of its target cells.

[Metabolic kinetics of MN9202 in Beagle dog liver microsomes].

AIM: To study the metabolic kinetics of MN9202 in Beagle dog liver microsome. METHODS: Beagle dog liver microsomes were prepared by using ultracentrifuge method. After incubating 0.4 micromol x L(-1) MN9202 with 1 g x L(-1) microsomes for 30 min at 37 degrees C, the reaction was terminated by adding 0.5 mL alkalization. The RP-HPLC was used to determine the drug in the incubation mixture. The Michaelis-Menten parameters Km, and Vmax in Beagle dog liver microsomes were initially estimated by analyzing Lineweave-Brurk plot. Various selective CYP inhibitors were used to investigate their inhibitory effect on the metabolism of MN9202. RESULTS: The Km, Vmax and CLint of MN9202 were (22.6 +/- 8.0) micromol x L(-1), (0.54 +/- 0.17) micromol x g(-1) x min(-1) and (0.0242 +/- 0.0009) L x g(-1) x min(-1), respectively. The metabolism of MN9202 was significantly inhibited by ketoconazole (Ket) and troleandomycin (Tro) in Beagle dog liver microsomes. Tranylcypromine (Tra) could inhibit the metabolism of drug as well. While other inhibitors showed little inhibitory effect on the metabolism of MN9202. CONCLUSION: It was shown that CYP3A and CYP2C19 were involved in MN9202 metabolism. The inhibitors of human CYP3A and CYP2C19 may have potential interaction with MN9202, and this can reduce the metabolism rate and increase the toxicity of MN9202.

[Pharmacokinetics of m-nifedipine in Beagle dogs].

AIM: To study the pharmacokinetics of m-nifedipine (m-Nif) in Beagle dogs. METHODS: The Beagle dogs were divided into two groups. m-Nif was intravenously administered to the Beagle dogs in group 1 at the dose of 0. 288 mg x kg(-1), and it was orally administered to the Beagle dogs in group 2, 3 and 4 at the dose of 1.152, 3.456 and 10.370 mg x kg(-1), respectively. m-Nif in plasma was detected by reversed phase high performance liquid chromatography. The pharmacokinetic parameters were calculated by 3P97 software. RESULTS: When m-Nif was intravenously administered, the plasma concentration-time curve was fit to a two-compartment model and T1/2beta was 117 min. When m-Nif was orally administered, the plasma concentration-time curve was fit to a one-compartment model. T1/2 (Ke) and Cmax were 147 min and 20 microg x L(-1); at the low dose of 1.152 mg x kg(-1). T1/2 (Ke) was 122 min and Cmax was 36 microg x L(-1) at the middle dose of 3.456 mg x kg(-1). T1/2 (Ke) was 144 min and Cmax was 69 microg x L(-1) at the high dose of 10.37 mg x kg(-1), respectively. CONCLUSION: It was showed that the speed of elimination of m-Nif was high in Beagle dogs. The absolute bioavailability of m-Nif given orally was very low.

Experimental study of anti-tumor effects of polysaccharides from Angelica sinensis.

AIM: To investigate the in vivo anti-tumor effects of total polysaccharide (AP-0) isolated from Angelica sinensis (Oliv.) Diels (Danggui) on mice and the in vitro inhibitory effects of AP-0 and the sub-constituents (AP-1, AP-2 and AP-3) separated from AP-0 on invasion and metastasis of human hepatocellular carcinoma. METHODS: Three kinds of murine tumor models in vivo, sarcoma 180 (S180), leukemia L1210 and Ehrlich ascitic cancer (EAC) were employed to investigate the anti-tumor effects of AP-0. For each kind of tumor model, three experimental groups were respectively given AP-0 at doses of 30, 100 and 300 mg/kg by ip once a day for 10 days. Positive control groups were respectively given Cy at a dose of 30 mg/kg for S180 and leukemia L1210, and 5-FU at a dose of 20 mg/kg for EAC. On d 11, mice bearing S180 were sacrificed and the masses of tumors, spleens and thymus weighed. The average living days of mice bearing EAC and of mice bearing L1210 were observed, and the rates of life prolongation of each treatment were calculated, respectively. The inhibitory effects of APs on hepatoma invasion and metastasis in vitro were investigated by employing human hepatocellular carcinoma cell line (HHCC) with the Matrigel invasion chamber, adhesion to extracellular matrix and chemotatic migration tests, respectively. RESULTS: AP-0 had no obviously inhibitory effect on the growth of S180, but it could significantly decrease the thymus weights of the mice bearing S180. AP-0 could significantly reduce the production of ascitic liquids and prolong the life of mice bearing EAC. AP-0 could also increase the survival time of mice bearing L1210. AP-0 and AP-2 had significantly inhibitory effects on the invasion of HHCC into the Matrigel reconstituted basement membrane with the inhibitory rates of 56.4 % and 68.3 %, respectively. AP-0, AP-1, AP-2 and AP-3 could influence the adhesion of HHCC to extracellular matrix proteins (Matrigel and fibronectin) at different degrees, among them only AP-3 had significant blocking effect on the adhesion of HHCC to fibronectin with an inhibitory rate of 30.3 %. AP-0, AP-1 and AP-3 could partially inhibit the chemotactic migration abilities of HHCC. CONCLUSION: The experimental findings suggest that the total polysaccharide of Angelica sinensis (Oliv.) Diels (Chinese Danggui) possesses anti-tumor effects on experimental tumor models in vivo and inhibitory effects on invasion and metastasis of hepatocellular carcinoma cells in vitro.