Brasilicardin A (BraA) is a natural diterpene glycoside isolated from the pathogenic actinomycete Nocardia brasiliensis IFM 0406 with highly potent immunosuppressive activity (IC₅₀=0.057 μg/mL). BraA potently inhibits the uptake of amino acids that are substrates for amino acid transport system L of T cells, which is different from the existing clinical immunosuppressants. BraA is more potent in a mouse mixed lymphocyte reaction and less toxic against various human cell lines compared with the known clinical immunosuppressants, such as cyclosporin A, ascomycin and tacrolimus. Therefore, BraA attracted more attention as a new promising immunosuppressant. However, the development of this promising immunosuppressant as drug for medical use is so far hindered because BraA has the unusual and synthetically challenging skeleton and shows the low-yield production in the natural pathogenic producer. This review introduces the molecular structure of BraA, its activity, mechanism of action, chemical synthesis of BraA analogs, heterologous expression of gene cluster, and an application of combining microbial and chemical synthesis for production of BraA, with the aim to facilitate the efficient production of BraA and its analogs.
Animals ; Mice ; Humans ; Immunosuppressive Agents/chemistry* ; Aminoglycosides/pharmacology* ; Cyclosporine/pharmacology* ; Diterpenes

OBJECTIVETo assess the effect of cyclosporine A (CsA) loaded in chitosan conduit on bridging the sciatic nerve defects in a rat model.

METHODSA 10 mm sciatic nerve defect was bridged using a chitosan conduit filled with 10 μl carrier-drug dilution (10 μg/L CsA). In control group, the conduit was filled with the same volume of carrier dilution alone. The regene-rated fibers were studied 4, 8 and 12 weeks after surgery.

RESULTSThe functional study confirmed faster recovery of the regenerated axons in treatment group than control group (P<0.05). There was statistically significant difference of the gastrocnemius muscle weight ratios between treatment and control groups (P<0.05). Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in CsA-treated animals were significantly higher than those in control group. In immunohistochemistry, the location of reactions to S-100 in CsA group was clearly more positive than control group.

CONCLUSIONCsA loaded in a chitosan conduit results in improvement of functional recovery and quantitative morphometric indices of sciatic nerve. It is easily available without any complications compared with its systemic administration.

Animals ; Chitosan ; Cyclosporine ; administration & dosage ; pharmacology ; Immunohistochemistry ; Nerve Regeneration ; drug effects ; Rats ; Sciatic Nerve ; chemistry ; injuries

In the past 50 years, organ transplantation has developed from an improbable laboratory exercise to a major therapeutic success. The surgical problems of organ grafting have, for the most part, been solved. Rejection of grafts is now partially understood and usually controllable by powerful immunosuppressive drugs. A steady improvement in patient outcome, especially following the introduction of cyclosporin as an immunosuppressive agent has resulted in a worldwide shortage of organs for transplantation. This has provoked serious ethical dilemmas in every country. These matters are summarised in the following text.
Biomedical Research ; Cyclosporine ; pharmacology ; Graft Rejection ; drug therapy ; prevention & control ; Humans ; Immunosuppression ; Immunosuppressive Agents ; pharmacology ; Transplants ; ethics

The intensive use of chemotherapeutic agents for the treatment of cancer has resulted in the cure or improved survival of many patients. But unfortunately, many cancers including human hepatocellular carcinoma (HCC) don't respond to chemotherapy. One of the major mechanisms for the drug resistance in the HCC is an elevated MDR1 RNA expression which makes cells become multidrug resistant. To overcome the multidrug resistance (MDR) phenotype, a high dose of verapamil is required both clinically and experimentally. Accordingly we have examined the MDR modulating effects with combinations of tamoxifen, cyclosporin A, and verapamil in vitro with the physiologically achievable concentrations of each agent, i.e., 2.0 microM/L for tamoxifen, 1.6 microM/L for cyclosporin A, and 2.5 microM/L for verapamil respectively in HCC lines. As expected, verapamil alone with the physiologically achievable concentration at which we tested didn't enhance the doxorubicin cytotoxicity in the HCC lines. Furthermore, any verapamil combination with cyclosporin A or tamoxifen was not effective in overcoming the doxorubicin resistance in the high MDR1 expressor (Hep-G2) line. However tamoxifen reduced the IC50 of doxorubicin by a factor of 1.9 in the low MDR1 expressor (SK-Hep1) and 1.1 in the high MDR1 expressor line (p< 10(-5) respectively). Of interest, combinations of tamoxifen and cyclosporin A showed a significant reduction in the IC50 of doxorubicin in both HCC lines. The IC50 of doxorubicin was reduced by a factor of 3.9 and 1.3, i.e., from 0.023943 micrograms/ml to 0.006157 micrograms/ml (p< 10(-5)) in the SK-Hep1 cell line, and 0.068819 micrograms/ml to 0.052442 micrograms/ml (p< 10(-5)) in Hep-G2 respectively when tamoxifen and cyclosporin A were administered together. Both the estrogen and progesterone receptors in the SK-Hep1 and Hep-G2 lines were less than 0.01 fmol/mg of cytosol protein, respectively. It is therefore suggested that the reversal of doxorubicin resistance is unrelated to their anti-estrogenic activity in the HCC lines. Three modulator combinations of tamoxifen, cyclosporin A, and verapamil were not more effective than the combination of tamoxifen and cyclosporin A on the sensitivity to doxorubicin. MDR modulators of tamoxifen, cyclosporin A, and verapamil didn't reduce the IC50 of cisplatin to the clinically achievable concentration range in HCC lines. In summary, the combination of tamoxifen and cyclosporin A at the concentrations normally seen after clinical administration of these modulators showed significant synergism on the sensitivity to doxorubicin in both low and high MDR1 expressor HCC lines. These data indicate the need for in vivo trials.
Antineoplastic Agents/*pharmacology ; Carcinoma, Hepatocellular/*physiopathology ; Cyclosporine/*pharmacology ; Drug Resistance ; Human ; Liver Neoplasms/*physiopathology ; Support, Non-U.S. Gov't ; Tamoxifen/*pharmacology ; Tumor Cells, Cultured/drug effects ; Verapamil/*pharmacology

The chemosensitizing effects of cyclosporin A and verapamil on the cytotoxicity of adriamycin were investigated using MTT assay against two human retinoblastoma cell lines, Y79 and WERI-Rb-1. Y79 and WERI-Rb-1 were totally resistant to doses up to 5.0 micrograms/ml of verapamil. Cyclosporin A inhibited the survival of Y79 and WERI-Rb-1 dose-dependently, however, the maximum inhibition at the highest concentration tested (5.0 micrograms/ml) was less than 50% (% survival at 5.0 micrograms/ml of cyclosporin A: 65.6% and 66.9% in Y79 and WERI-Rb-1, respectively). Combination of cyclosporin A and verapamil did not further inhibit the survival of Y79 and WERI-Rb-1 compared with cyclosporin A alone. Adramycin inhibited the survival of Y79 and WERI-Rb-1 dose-dependently. The chemosensitizing effects of cyclosporin A and verapamil on the cytotoxicity of adriamycin were evaluated in terms of sensitizing index (SI: the ratio of IC50 to adriamycin alone to IC50 to adriamycin in the presence of cyclosporin A and/or verapamil). Cyclosporin A significantly enhanced SI and the addition of verapamil enhanced SI further: SI values at 5.0 micrograms/ml of cyclosporin A, 5.0 micrograms/ml of cyclosporin A plus 1.5 micrograms/ml of cyclosporin A plus 1.5 micrograms/ml of verapamil, 5.0 micrograms/ml of cyclosporin A plus 3.0 micrograms/ml of verapamil were 2.0, 2.6 and 2.8 in Y79 and 2.6, 5.8 and 9.7 in WERI-Rb-1, respectively. These results suggest that cyclosporin A and verapamil are promising chemosensitizers to adriamycin in the treatment of retinoblastoma.
Cell Survival/drug effects ; Cyclosporine/*pharmacology ; Doxorubicin/*pharmacology ; Eye Neoplasms/drug therapy/*pathology ; Humans ; Retinoblastoma/drug therapy/*pathology ; Tumor Cells, Cultured ; Verapamil/*pharmacology

OBJECTIVETo investigate the changes of serum inteferon-gamma (IFN-gamma) in mice bearing S-180 tumor and explore the role of the endogenous IFN-gamma in confining the transplanted tumor by intervention with immunomodulators.

METHODSMouse models bearing S-180 solid tumor were established and subjected to intragastric administration of Ganoderma lucidum polysaccharides (GLP) or cyclosporine A (CsA) at different daily doses for 9 consecutive days. Serum IFN-gamma levels were measured in untreated tumor-bearing mice and in those after completion of GLP or CsA treatments by enzyme-linked immunosorbent assay (ELISA), and the changes of the tumor weight in the treated mice were evaluated.

RESULTSIt was found for the first time that serum IFN-gamma levels in the tumor-bearing mice increased progressively within the initial 20 days after tumor implantation. The serum IFN-gamma levels in the 3 GLP-treated groups (at daily doses of 400, 200, and 100 mg/kg) all increased, which was the most obvious in 400 mg/kg GLP-treated group, and the tumor weight decreased significantly in response to GLP treatment, but the most conspicuous effect occurred with the daily dose of 200 mg/kg, and no significant statistical correlation was found between the two parameters. CsA treatment (at 20, 10, and 5 mg/kg, respectively) resulted in reduced serum IFN-gamma levels but produced virtually no effect on the tumor weight, and no obvious correlation was found between serum IFN-gamma level and the tumor weight.

CONCLUSIONIncreased serum IFN-gamma levels following GLP treatment are not significantly correlated to tumor growth inhibition in mice, and CsA reduces serum IFN-gamma levels without affecting the tumor weight, suggesting that endogenous IFN-gamma is not a major immunomodulating factor in growth inhibition of transplanted S-180 tumor.

Animals ; Cyclosporine ; pharmacology ; Female ; Ganoderma ; chemistry ; Immunologic Factors ; pharmacology ; Interferon-gamma ; blood ; Male ; Mice ; Polysaccharides ; pharmacology ; Sarcoma 180 ; blood ; pathology ; prevention & control ; Tumor Burden ; drug effects

The study was purposed to investigate the synergistic reversal effect of Chinese medicine compound FFJZ in combination with cyclosporine A (CsA) on the multidrug resistance (MDR) of human leukemia K562/VCR cell line, as to search effective combination of MDR modulators. MTT (methyl-thazol-tetrazolinum) assay were used to determine the cytotoic and reversal effects on K562/VCR cell line, FCM (flow cytometry) was used to assess the intracellular adriamycin (ADM) concentration and the expression of P-gp in cells. The results showed that the FFJZ in combination with CsA could reverse the drug-resistance of K562/VCR cells and increase the sensitivity K562/VCR cells to adriamycin. They had not the toxic effect on the K562/VCR cells in effective dose and no significant influence on P-gp positive rate of the K562/VCR cells. It is concluded that the FFJZ in combination with CsA may become a safe and effective multidrug resistance-reversing agent with low toxicity in leukemia chemotherapy.
Cyclosporine ; pharmacology ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Drug Synergism ; Drugs, Chinese Herbal ; pharmacology ; Humans ; K562 Cells ; Vincristine ; pharmacology

Calcineurin inhibitors, tacrolimus and cyclosporine, characterized by a narrow therapeutic index and a high variability in pharmacokinetic behaviors, are 2 basic immunosuppressive drugs widely used in solid organ transplantation. Tailoring of immunosuppressive drug therapy to the specific requirements of individual patients to optimize the efficacy and minimize the toxicity remains one of the biggest challenges for doctors in solid organ transplantation. Pharmacogenetic and pharmacogenomic researches, studying the effect of genetic polymorphism encoding drug metabolizing enzymes, drug transporters and pharmacological target molecules on drug disposition and action, hold promise to produce useful clinical tools for individualizing immunosuppressive therapy.
Animals ; Calcineurin Inhibitors ; Cyclosporine ; pharmacokinetics ; pharmacology ; Cytochrome P-450 CYP3A ; genetics ; Humans ; Immunosuppressive Agents ; pharmacokinetics ; pharmacology ; Organ Transplantation ; Polymorphism, Genetic ; Tacrolimus ; pharmacokinetics ; pharmacology

To explore the possibility of leukemia cell line of both bcr-abl and mdr-1 positive were cross-resistant to tyrosine kinase inhibitor STI571 and its reversal way, the inhibitory effect of STI571 on K562-n/VCR cells was detected with MTT method and reverse effects of CsA, TAM, IFN-alpha and CsA cominated with IFN-alpha were observed. The results showed that K562-n/VCR cell line expressing bcr-abl and mdr1 positive was resistant to STI571, and could be reversed by 5.18, 1.82 and 1.67-fold respectively, when treated with CsA, TAM, and IFN-alpha. It could be reversed by 34.87-fold with combination of half-dose CsA and IFN-alpha. In conclusion, amplification of mdr1 gene may contribute to drug-resistance of bcr-abl positive leukemic cells against STI571. The reversal agents, CsA, TAM and IFN-alpha show obviously reverse effects on drug-resistance. The combination of half-dose of both CsA and IFN-alpha display stronger effect than the full dose of either.
Antineoplastic Agents ; pharmacology ; Benzamides ; Cyclosporine ; pharmacology ; Drug Resistance, Neoplasm ; Genes, MDR ; Genes, abl ; Humans ; Imatinib Mesylate ; Interferon-alpha ; pharmacology ; K562 Cells ; Leukemia ; drug therapy ; genetics ; Piperazines ; pharmacology ; Pyrimidines ; pharmacology ; Tamoxifen ; pharmacology

The paper is aimed to investigate the effect of cyclosporine A (CyA) on the pharmacokinetics of ginkgolide B (GB) in rats, and to look for the mechanism of the changes in pharmacokinetic behaviors of GB. GB concentration in plasma, brain homogenate and urine samples of rats was determined by LC-MS. Effects of CyA on plasma levels, brain distributions as well as urinary excretions after intravenous administration of GB were evaluated. CyA co administrated intravenously at 10 mg kg(-1) or 20 mg kg(-1) significantly increased AUC(0-360 min) (P < 0.01) and decreased total CL of GB in rats. While co administrated CYP3A inhibitor itraconazole (ICZ) has no appreciable effect on the pharmacokinetic behavior of GB. CyA increased the brain uptake of GB in a dose-dependent manner. The brain distribution of GB was significantly increased at 5 min by different doses of CyA (P < 0.001), while at 20 and 60 min only high dose of CyA could significantly increase the levels of GB in the brain (P < 0.01 and P < 0.001). Different P-gp inhibitors CyA or verapamil (VER) or digoxin (DGX) decreased the urinary GB excretion, the urinary excretion of GB in 0-8 h were about 34.8% (P < 0.001), 59.4% (P < 0.001) and 79.7% (P < 0.05) of the control, separately. No appreciable effect of ICZ was observed on urinary excretion of GB. Coadministration of P-gp inhibitors CyA could significantly increase the plasma level, accelerate the brain distribution and decrease the urinary excretion of GB.
Animals ; Cyclosporine ; pharmacology ; Ginkgolides ; pharmacokinetics ; Herb-Drug Interactions ; Lactones ; pharmacokinetics ; Male ; Rats ; Rats, Sprague-Dawley ; Tissue Distribution