Effect of Oregon grape root extracts on P-glycoprotein mediated transport in in vitro cell lines.

Purpose: This study aims to investigate the potential of Oregon grape root extracts to modulate the activity of P-glycoprotein. Methods: We performed 3H-CsA or 3H-digoxin transport experiments in the absence or presence of two sources of Oregon grape root extracts (E1 and E2), berberine or berbamine in Caco-2 and MDCKII-MDR1 cells. In addition, real time quantitative polymerase chain reaction (RT-PCR) was performed in Caco-2 and LS-180 cells to investigate the mechanism of modulating P-glycoprotein. Results: Our results showed that in Caco-2 cells, Oregon grape root extracts (E1 and E2) (0.1-1 mg/mL) inhibited the efflux of CsA and digoxin in a dose-dependent manner. However, 0.05 mg/mL E1 significantly increased the absorption of digoxin. Ten µM berberine and 30 µM berbamine significantly reduced the efflux of CsA, while no measurable effect of berberine was observed with digoxin. In the MDCKII-MDR1 cells, 10 µM berberine and 30 µM berbamine inhibited the efflux of CsA and digoxin. Lastly, in real time RT-PCR study, Oregon grape root extract (0.1 mg/mL) up-regulated mRNA levels of human MDR1 in Caco-2 and LS-180 cells at 24 h. Conclusion: Our study showed that Oregon grape root extracts modulated P-glycoprotein, thereby may affect the bioavailability of drugs that are substrates of P-glycoprotein.

Evaluation of different almond (Terminalia catappa) extracts against oxidative stress induced by cyclosporine in brain and liver of rats.

OBJECTIVES: This study was designed to evaluate the ameliorative effect of almond (Terminalia catappa) leaf (ALE) and stem bark (ABE) extracts on the enzyme activities and oxidative stress markers in the brain and liver tissues of cyclosporine-A (CsA) stressed male albino rats. METHODS: Eighty-eight adult male rats weighing between 200 and 220 g were randomly distributed to into 11 groups (n=8) and different doses (100 and 200 mg/kg bwt.) of ALE and ABE were administered through oral gavages to the normal rats and 50 mg/kg/bwt/day CsA-stressed, while normal control rats was given a saline solution (p.o), and the treatment lasted for 14 days. Blood plasma, liver and brain tissues were prepared for biochemical analysis. RESULTS: Neuronal [acetylcholinesterase (AChE) and butrylcholinesterase (BChE) and arginase] enzyme activities and thiobarbituric acid reactive species (TBARS) level, plasma aspartate transferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities, liver non-protein thiol (NPSH) level were analyzed. The results revealed that, the administration of CsA induced a significant increase in neuronal AChE, BChE, arginase, TBARS level, but decreased nitric oxide (NO) level. CsA also increased ALT, AST, and ALP activities in the blood plasma of CsA stress rats compared to normal control, but were significantly reversed respectively (p<0.001) upon treatment with the ALE and ABE dose-dependently. CONCLUSIONS: The study revealed that ALE and ABE could prevent neuronal dysfunction and liver toxicity induced by CsA administration, however, higher dose (200 mg/kg) of the studied extracts appears to be more potent.

Evaluating the novel application of cyclosporine 0.1% in ocular surface disease.

INTRODUCTION: Ocular surface disease (OSD) is a highly prevalent symptomatic condition caused by dry eye disease (DED), intrinsic, environmental, or iatrogenic causes. It affects patient's visual function and quality of life. Its pathophysiology is centered on tear hyperosmolarity, inflammation, and epithelial damage. Current management is suboptimal and includes artificial tear supplementation and short-term use of topical steroids in severe cases. The recent approval of cyclosporine 0.1% has transformed management strategies of severe DED and moderate-to-severe OSD. Areas covered: This review summarizes existing information on the efficacy, safety, and tolerability of the new cyclosporine 0.1% formulation. Expert opinion: Topical cyclosporine A 0.1% represents a promising, novel medication for the management of DED, Meibomian gland dysfunction, and inflammatory OSD. It is primarily beneficial for those patients requiring topical immunomodulatory therapy. This topical formulation also has the potential to meaningfully improve the management of moderate-to-severe glaucoma therapy-related OSD. Currently there is limited published clinical data concerning the efficacy of topical cyclosporine. There are, however, theoretical advantages when comparing this cyclosporine formulation with other established commercial preparations. Future research is needed to delineate the precise role and value of this medication.

Integrating multi-omics analyses of Nonomuraea dietziae to reveal the role of soybean oil in [(4'-OH)MeLeu]4-CsA overproduction.

BACKGROUND: Nonomuraea dietziae is a promising microorganism to mediate the region-specific monooxygenation reaction of cyclosporine A (CsA). The main product [(4'-OH)MeLeu]4-CsA possesses high anti-HIV/HCV and hair growth-stimulating activities while avoiding the immunosuppressive effect of CsA. However, the low conversion efficiency restricts the clinical application. In this study, the production of [(4'-OH)MeLeu]4-CsA was greatly improved by 55.6% from 182.8 to 284.4 mg/L when supplementing soybean oil into the production medium, which represented the highest production of [(4'-OH)MeLeu]4-CsA so far. RESULTS: To investigate the effect of soybean oil on CsA conversion, some other plant oils (corn oil and peanut oil) and the major hydrolysates of soybean oil were fed into the production medium, respectively. The results demonstrated that the plant oils, rather than the hydrolysates, could significantly improve the [(4'-OH)MeLeu]4-CsA production, suggesting that soybean oil might not play its role in the lipid metabolic pathway. To further unveil the mechanism of [(4'-OH)MeLeu]4-CsA overproduction under the soybean oil condition, a proteomic analysis based on the two-dimensional gel electrophoresis coupled with MALDI TOF/TOF mass spectrometry was implemented. The results showed that central carbon metabolism, genetic information processing and energy metabolism were significantly up-regulated under the soybean oil condition. Moreover, the gas chromatography-mass spectrometry-based metabolomic analysis indicated that soybean oil had a great effect on amino acid metabolism and tricarboxylic acid cycle. In addition, the transcription levels of cytochrome P450 hydroxylase (CYP) genes for CsA conversion were determined by RT-qPCR and the results showed that most of the CYP genes were up-regulated under the soybean oil condition. CONCLUSIONS: These findings indicate that soybean oil could strengthen the primary metabolism and the CYP system to enhance the mycelium growth and the monooxygenation reaction, respectively, and it will be a guidance for the further metabolic engineering of this strain.

Bioprinting of 3D Convoluted Renal Proximal Tubules on Perfusable Chips.

Three-dimensional models of kidney tissue that recapitulate human responses are needed for drug screening, disease modeling, and, ultimately, kidney organ engineering. Here, we report a bioprinting method for creating 3D human renal proximal tubules in vitro that are fully embedded within an extracellular matrix and housed in perfusable tissue chips, allowing them to be maintained for greater than two months. Their convoluted tubular architecture is circumscribed by proximal tubule epithelial cells and actively perfused through the open lumen. These engineered 3D proximal tubules on chip exhibit significantly enhanced epithelial morphology and functional properties relative to the same cells grown on 2D controls with or without perfusion. Upon introducing the nephrotoxin, Cyclosporine A, the epithelial barrier is disrupted in a dose-dependent manner. Our bioprinting method provides a new route for programmably fabricating advanced human kidney tissue models on demand.

Novel in vitro transport method for screening the reversibility of P-glycoprotein inhibitors.

The purpose of this study was to establish a novel in vitro method for screening reversibility of P-glycoprotein (P-gp) inhibitors. Caco-2 cells with 21days of cultivation were used as an in vitro model. Transport of rhodamine 123 in the presence of various inhibitors and after removing of inhibitors was determined. Transport of rhodamine 123 at 4°C and in the secretory direction assured that Caco-2 cells exhibited P-gp function at all time of experiment. The apparent permeability coefficient (Papp) of rhodamine 123 in the presence of verapamil, cyclosporin A, ritonavir, quinidine, N-ethylmaleimide, Cremophor® EL, Tween 80 and poly(acrylic acid)-cysteine-2-mercaptonicotinic acid (PAA-cys-2MNA) was 2.3-, 3.8-, 2.3-, 3.1, 7.5-, 2.1-, 2.9- and 2.5-fold higher than Papp of rhodamine 123 alone. After removing of the inhibitors, Papp decreased to the same range of control except in the case of N-ethylmaleimide which was 2.4-fold higher than the control. These results revealed a reversible inhibition of verapamil, cyclosporin A, ritonavir, quinidine, Cremophor® EL, Tween 80 and PAA-cys-2MNA and an irreversible inhibition of N-ethylmaleimide for P-gp. Thus, this novel established that in vitro method might be an effective tool for screening the reversibility of inhibition of P-gp inhibitors.

Human structural proteome-wide characterization of Cyclosporine A targets.

MOTIVATION: Off-target interactions of a popular immunosuppressant Cyclosporine A (CSA) with several proteins besides its molecular target, cyclophilin A, are implicated in the activation of signaling pathways that lead to numerous side effects of this drug. RESULTS: Using structural human proteome and a novel algorithm for inverse ligand binding prediction, ILbind, we determined a comprehensive set of 100+ putative partners of CSA. We empirically show that predictive quality of ILbind is better compared with other available predictors for this compound. We linked the putative target proteins, which include many new partners of CSA, with cellular functions, canonical pathways and toxicities that are typical for patients who take this drug. We used complementary approaches (molecular docking, molecular dynamics, surface plasmon resonance binding analysis and enzymatic assays) to validate and characterize three novel CSA targets: calpain 2, caspase 3 and p38 MAP kinase 14. The three targets are involved in the apoptotic pathways, are interconnected and are implicated in nephrotoxicity.

In vivo microdialysis with LC-MS for analysis of spinosin and its interaction with cyclosporin A in rat brain, blood and bile.

Spinosin, a major bioactive herbal ingredient isolated from Semen Ziziphi Spinosae, plays an important role in sedation and hypnosis. However, the pharmacokinetic behavior of spinosin in special sites has not been reported. Microdialysis (MD) technique, as a continuous, realtime monitoring sampling technique, is very suitable for the evaluation of the disposition of diverse drugs. To obtain more useful information on spinosin, an in vivo microdialysis sampling technique with High Performance Liquid Chromatography-mass spectrograph (HPLC-MS) method was developed to investigate the pharmacokinetics of spinosin and its interaction with cyclosporin A (CsA) in the brain, blood and bile of rats. The method was validated in terms of selectivity, linearity and sensitivity, and showed advantages in monitoring the pharmacokinetic behavior of drugs. The results revealed that CsA has obvious effects on the pharmacokinetic process of spinosin. When co-administered, the area under the curve (AUC) of spinosin in blood, bile and brain increased from 205.70 to 673.51 mg min/L, 7.77 × 10(4) to 1.25 × 10(5) mg min/L, and 2.09 to 5.58 mg min/L, respectively. The t(1/2) values of spinosin in blood, bile and brain also changed from 48.07 to 95.04 min, from 97.20 to 152.21 and from 42.18 to 73.83 min, respectively. These results demonstrated that the CsA decreased the efflux of spinosin through the inhibition of P-glycoprotein (P-gp) efflux transporter and it might be used as a group of P-gp substrate. Other transporters or pathways may also be involved in the metabolism of spinosin.

Gender- and dose-related effects of cyclosporin A on hepatic and bone metabolism.

Previous data have shown gender-related differences in the skeletal effects of the immunosuppressive drug cyclosporin A (CsA) in rats. To test the hypothesis that the gender-related skeletal effects of CsA are caused by gender-specific metabolism of this drug, we treated aged male and female sham-operated, gonadectomized (GX) as well as sex hormone-supplemented GX rats with 5 mg/kg CsA three times per week for 2 months, and analyzed the bone phenotype as well as the concentrations of CsA and its major metabolites AM1, AM1c, AM9, and AM4N in blood, urine, and liver tissue. CsA treatment induced high turnover osteopenia in males, but not females. Male rats showed several-fold higher CsA and CsA metabolite blood levels compared with females. Renal clearance data revealed that CsA undergoes selective tubular reabsorption in male, but not female rats. However, a mathematical modeling approach demonstrated that the higher CsA blood levels in males were almost exclusively caused by a 6-fold lower hepatic clearance rate compared with females. In addition, we subcutaneously treated female rats with up to 6-fold higher doses of CsA. Similar to males, high dose CsA induced high turnover osteopenia in female rats. Our data show that the gender-related differences in the skeletal effects of CsA are caused by a higher hepatic clearance rate for CsA in female compared to male rats, and not by a differential skeletal response to CsA. Moreover, our study indicates that CsA blood levels of ≤200 ng/ml measured by HPLC do not induce high turnover osteopenia in aged rats.

Steroid withdrawal based on lymphocyte sensitivity to endogenous steroid in renal transplant recipients.

Though steroid withdrawal is done in many renal transplant recipients, some patients must restart steroids. Little report has investigated steroid withdrawal under pharmacodynamic monitoring. We assessed lymphocyte sensitivity to endogenous cortisol as a biomarker for determining the safety of steroid withdrawal in renal transplant patients, as we hypothesized that patients hyposensitive to cortisol could not be sufficiently immunosuppressed by their intrinsic cortisol as a substitute for the reduced or withdrawn steroid. Lymphocyte sensitivity to cortisol was examined in 30 long stable renal transplant recipients. Lymphocyte sensitivity to cortisol and its relationship with the clinical outcome after steroid reduction and withdrawal was investigated. The lymphocyte sensitivities to cortisol were estimated as IC(50) of lymphocyte blastogenesis. The lymphocyte proliferation rate for concentration of serum cortisol compared between incident and non-incident groups. Serum creatinine levels (S-Cr) increased in a significantly higher number of patients hyposensitive to cortisol (IC(50)≧10000 ng/ml) than in normally sensitive patients (IC(50)<10000 ng/ml). The incidences of steroid withdrawal syndrome and necessity for increasing steroid dose or restarting steroid administration were also higher in the patients hyposensitive to cortisol. The patients in whom the lymphocyte proliferation rate was less than 60% did not show increase in S-Cr, experience steroid withdrawal symptoms, or require an increase in the steroid dose or restart of steroid administration. The patients who have the normal IC(50) values of cortisol, can withdraw steroid more safely. The lymphocyte sensitivity to cortisol may be a useful biomarker for selecting patients who can sustain steroid withdrawal.

Intestinal absorption mechanisms of berberine, palmatine, jateorhizine, and coptisine: involvement of P-glycoprotein.

The absorption and transport mechanisms of berberine, palmatine, jateorhizine, and coptisine were studied using a Caco-2 cells uptake and transport model, with the addition of cyclosporin A and verapamil as P-glycoprotein (P-gp) inhibitors and MK-571 as a multidrug resistance-associated protein 2 (MRP(2)) inhibitor. In the uptake experiment, berberine, palmatine, jateorhizine, and coptisine were all taken into Caco-2 cells, and their uptakes were increased in the presence of cyclosporin A or verapamil. In the transport experiment, P(app) (AP-BL) was between 0.1 and 1.0 × 10(6) cm/sec for berberine, palmatine, jateorhizine, and coptisine and was lower than P(app) (BL-AB). ER values were all >2. Cyclosporin A and verapamil both increased P(app) (AP-BL) but decreased P(app) (BL-AB) for berberine, palmatine, jateorhizine, and coptisine; ER values were decreased by >50%. MK-571 had no influence on the transmembrane transport of berberine, palmatine, jateorhizine, and coptisine. At a concentration of 1-100 µM, berberine, palmatine, jateorhizine, and coptisine had no significant effects on the bidirection transport of Rho123. Berberine, palmatine, jateorhizine, and coptisine were all P-gp substrates; and at the range of 1-100 µM, berberine, palmatine, jateorhizine, and coptisine had no inhibitory effects on P-gp.

Absence of drug interaction between Hwang-Ryun-Hae-Dok-Tang and phenolsulfonphthalein.

Hwang-Ryun-Hae-Dok-Tang (HT; a standardized herbal formula consisting of extracts from Coptidis Rhizoma, Scutellariae Radix, Phellodendri Cortex, and Gardeniae Fructus) was reported to modulate a function of multidrug resistance associated protein 2 (Mrp2) in vitro. The aim of this study was to assess the in vivo pharmacokinetic interactions between HT and phenolsulfonphthalein (PSP), a typical model Mrp2 substrate eliminated via bile through Mrp2 in rats. Rats received intravenous PSP (0.8 mg/kg) followed by either a single oral dose of HT (0.42 g/kg) or multiple oral doses of HT (0.42 g/kg for 7 days). The effect of HT treatment was also investigated at a steady-state after intravenous PSP infusion. In contrast to previous in vitro results, in this study, we found that the HT-treated and control groups did not show any significant difference in the plasma PSP concentration and pharmacokinetic parameters, including area under the plasma concentration-time curve (AUC; control: 118 ± 19, single dose: 116 ± 40, and multiple dose: 137 ± 4, in mg/(min·mL)) and biliary clearance (control: 3.15 ± 0.69, single dose: 2.59 ± 1.11, and multiple dose: 2.53 ± 0.65, in mL/(min·kg)). However, cyclosporine A (5 mg/kg, an inhibitor of Mrp2) significantly decreased the AUC and biliary clearance of PSP. The steady-state plasma concentration and biliary clearance of PSP-were also similar between the groups. Taken together, our results suggest that HT may not be affected by Mrp2-mediated herb-drug interaction in vivo.

Statistical optimization for improved production of cyclosporin a in solid-state fermentation.

This work evaluates the effect of different amino acids on production of CyA production in solid-state fermentation that was previously optimized for different fermentation parameters by one-factor-at-a-time for the maximum production of CyA by Tolypocladium inflatum MTCC 557. Based on the Plackett-Burman design, glycerol, ammonium sulfate, FeCl3, and inoculum size were selected for further optimization by response surface methodology (RSM). After identifying effective nutrients, RSM was used to develop mathematical model equations, study responses, and establish the optimum concentrations of the key nutrients for higher CyA production. It was observed that supplementation of medium containing (% w/w) glycerol, 1.53; ammonium sulfate, 0.95; FeCl3, 0.18; and inoculum size 6.4 ml/5g yielded a maximum of 7,106 mg/kg as compared with 6,480 mg CyA/kg substrate using one factor at a time. In the second step, the effect of amino acids on the production of CyA was studied. Addition of L-valine and L-leucine in combination after 20 h of fermentation resulted in maximum production of 8,166 mg/kg.

A novel medium for the enhanced production of cyclosporin A by Tolypocladium inflatum MTCC 557 using solid state fermentation.

Cyclosporin A (CyA) produced by Tolypocladium inflatum is a promising drug owing to its immunosuppressive and antifungal activities. From an industrial point of view, the necessity to obtain a suitable and economic medium for higher production of CyA was the aim of this work. The present study evaluated the effect of different fermentation parameters in solid state fermentation, such as selection of solid substrate, hydrolysis of substrates, initial moisture content, supplementation of salts, additional carbon, and nitrogen sources, as well as the inoculum age and size, on production of CyA by Tolypocladium inflatum MTCC 557. The fermentation was carried out at 25+/-2 degrees for 9 days. A combination of hydrolyzed wheat bran flour and coconut oil cake (1:1) at 70% initial moisture content supported a maximum production of 3,872+/-156 mg CyA/kg substrate as compared with 792+/-33 mg/kg substrate before optimization. Furthermore, supplementation of salts, glycerol (1%w/w), and ammonium sulfate (1%w/w) increased the production of CyA to 5,454+75 mg/kg substrate. Inoculation of 5 g of solid substrate with 6 ml of 72-h-old seed culture resulted in a maximum production of 6,480+95 mg CyA/kg substrate.

Mycobacteria attenuate nociceptive responses by formyl peptide receptor triggered opioid peptide release from neutrophils.

In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as arthritic pain. In rats, inflammatory pain is induced by intraplantar injection of heat inactivated Mycobacterium butyricum, a component of complete Freund's adjuvant. We hypothesized that mycobacterially derived formyl peptide receptor (FPR) and/or toll like receptor (TLR) agonists could activate neutrophils, leading to opioid peptide release and inhibition of inflammatory pain. In complete Freund's adjuvant-induced inflammation, thermal and mechanical nociceptive thresholds of the paw were quantified (Hargreaves and Randall-Selitto methods, respectively). Withdrawal time to heat was decreased following systemic neutrophil depletion as well as local injection of opioid receptor antagonists or anti-opioid peptide (i.e. Met-enkephalin, beta-endorphin) antibodies indicating an increase in pain. In vitro, opioid peptide release from human and rat neutrophils was measured by radioimmunoassay. Met-enkephalin release was triggered by Mycobacterium butyricum and formyl peptides but not by TLR-2 or TLR-4 agonists. Mycobacterium butyricum induced a rise in intracellular calcium as determined by FURA loading and calcium imaging. Opioid peptide release was blocked by intracellular calcium chelation as well as phosphoinositol-3-kinase inhibition. The FPR antagonists Boc-FLFLF and cyclosporine H reduced opioid peptide release in vitro and increased inflammatory pain in vivo while TLR 2/4 did not appear to be involved. In summary, mycobacteria activate FPR on neutrophils, resulting in tonic secretion of opioid peptides from neutrophils and in a decrease in inflammatory pain. Future therapeutic strategies may aim at selective FPR agonists to boost endogenous analgesia.

Pharmacokinetics of kadsurenone and its interaction with cyclosporin A in rats using a combined HPLC and microdialysis system.

Kadsurenone is a neolignan with specific antagonistic activity of platelet-activating factor, and is derived from the stems of Piper kadsura. To investigate the mechanism of hepatobiliary excretion of kadsurenone and its association with P-glycoprotein (P-gp), and to explore whether the hepatobiliary excretion of kadsurenone was associated with P-gp, a microdialysis system coupled with HPLC was developed to measure free-form kadsurenone in rat blood and bile. This study design was parallel in the following groups: six rats received kadsurenone alone (20 and 30 mg/kg, i.v.) as control group and the treated-group rats were co-administered with kadsurenone and CsA; P-gp inhibitor. The microdialysis probes were respectively inserted into the jugular vein toward right atrium and bile duct of male Sprague-Dawley rats for blood and bile sampling. CsA (20mg/kg) was administered 10 min prior to kadsurenone administration through the femoral vein and the collected samples were analyzed by a HPLC system. The analytes were separated by a C18 column (150 x 4.6 mm I.D., 5 microm) with a mobile phase of acetonitrile-water (50:50, v/v) at a flow-rate of 1 mL/min. The UV detection wavelength was set 235 nm. The calibration curve was linear over the concentration range of 0.05-10 microg/mL with the coefficient of determination of 0.997. The inter- and intra-assay accuracy and precision of the method ranged from -9.53% to 6.75%. The limit of detection and the limit of quantification were 0.01 and 0.05 microg/mL, respectively. The hepatobiliary excretion ratio of kadsurenone was defined by dividing the values of the area under the drug concentration curve (AUC) for bile and blood (AUC(bile)/AUC(blood)). The results indicated that the hepatobiliary excretion ratio of kadsurenone on the CsA treated-group was 1.2+/-0.1, which was not significantly different from the group of kadsurenone alone (1.3+/-0.2). This fact indicates that kadsurenone went through hepatobiliary excretion but might not be regulated by P-gp.

Possible therapeutic effect of lipid supplementation on neurological complications in liver transplant recipients.

Neurological complications (NCs) represent a serious problem following liver transplantation and may develop either because of various peri-operative factors or the toxicity of immunosuppression. Although the causality assessment of NCs can be particularly difficult in the setting of organ transplantation, calcineurin inhibitors (CNIs) might influence NCs to a certain extent, regardless of the etiology. Therefore, minimizing the influence of CNIs could be a reasonable strategy for alleviating NCs. Based on our hypothesis that lipid supplementation prevents lipophilic CNIs from crossing the blood-brain barrier, soybean oil was administered to five liver transplant patients with NCs. In all of these patients, the neurological symptoms improved without discontinuing or reducing the dose of CNIs. Thus, lipid supplementation might be able to reduce the adverse neurological effects of CNIs.

Effect of oral vitamin E and C therapy on calcineurin inhibitor levels in heart transplant recipients.

BACKGROUND: A recent prospective trial demonstrated that oral vitamins C and E retard the early progression of transplant-associated coronary arteriosclerosis; as a result, a number of centers have added these agents to their maintenance regimens. This study reviewed the impact of vitamin E and C supplementation on calcineurin inhibitor trough concentrations. METHODS: A retrospective chart review of the first 29 heart transplant patients prescribed anti-oxidant agents was performed. Twenty-two patients taking cyclosporin A (CsA) and 7 patients taking tacrolimus were prescribed vitamin C (500 mg twice a day) and vitamin E (400 IU twice a day). Serum chemistries and drug levels were measured before and after vitamin therapy was initiated. RESULTS: The baseline CsA trough concentration (mean +/- SD) was 137 +/- 39 ng/ml and it declined to 99 +/- 54 ng/ml (p = 0.007) after anti-oxidant therapy was initiated. The average percentage decrease in the CsA trough concentration was 30%. No significant changes were seen in the patients taking tacrolimus. CONCLUSIONS: These data demonstrate that supplementation with the anti-oxidant agents vitamin C and vitamin E decreases CsA concentrations but does not appear to effect tacrolimus concentrations. Although more detailed pharmacokinetic analysis is necessary to clarify the exact mechanism of this interaction, physicians who take care of transplant recipients should be aware that more frequent CsA concentration monitoring is warranted after initiating these anti-oxidant agents.

Studies on the application of immobilization technique for the production of cyclosporin A by a local strain of Aspergillus terreus.

The formation of cyclosporin A (Cy A) by immobilized spores and mycelia of Aspergillus terreus was investigated. Different carriers were tested as immobilizing carriers, whereby Ca-alginate was selected for further experimentation. The role of alginate concentration, biomass weight, pH value of the cultivation medium, repeated utilization of the immobilized fungus as well as the supplementation of different amino acid precursors were studied. Best Cy A outputs were attained with Ca-alginate 3% (w/v), mycelial weight 15% (w/v), pH 4.5 and four repeated cycles. Similarly, the Cy A productivity was markedly accelerated in the presence of L-valine and L-valine and L-leucine mixture.

Astilbin suppresses collagen-induced arthritis via the dysfunction of lymphocytes.

OBJECTIVE AND DESIGN: To examine the therapeutic effects of astilbin, a flavanoid isolated from Rhizoma Smilacis Glabrae, on arthritis and to compare it with cyclosporine A (CsA). MATERIALS AND METHODS: Type II collagen-induced arthritis in mice and its in vitro assays for proliferation, matrix metalloproteinase (MMP) and NO production were performed. RESULTS: Astilbin dose-dependently inhibited the footpad swelling, arthritic incidence, and clinical scores without influencing the body weights, while CsA showed strong inhibition with a significant weight loss. Histological examination revealed marked inflammatory damage in arthritic mice including joint swelling, synovial hyperplasia, and cartilage destruction. Against these, an intact joint structure was maintained in astilbin-treated or CsA-treated mice. In isolated spleen cells from arthritic mice, increased potentials in proliferation, NO production, and MMP-2 and 9 activities were suppressed dose-dependently by the oral administration of astilbin. Additionally, astilbin showed neither any cytotoxicity to nor influence on Con A-induced proliferation of spleen cells from naive mice, while CsA showed a dose-dependent cytotoxicity and inhibition of the proliferation. CONCLUSIONS: Astilbin may act as an efficient therapeutic agent for arthritis like CsA but with less toxicity. Its mechanism includes a selective suppression on lymphocyte functions via reducing MMP and NO production.