Pharmacoimmunodynamics of methylprednisolone: trafficking of helper T lymphocytes.

A two-compartment closed model was used to characterize the cell trafficking behavior of helper T cells in response to various single doses of methylprednisolone. Steroids are assumed to inhibit the circadian-determined cell return from extravascular sites to blood in a classic inhibitory pattern reflected by an IC50. The rate of cell efflux from tissues is modeled with a cosine function having a period of 24 hr and a maximum at about 1 AM. Nonlinear least-squares regression employing differential equations was used to analyze helper T-cell data from three human studies from our laboratory. The IC50 value of methylprednisolone of 12-19 ng/ml approximates receptor KD values. Simulations were performed to demonstrate the log-linear role of steroid dose or AUC on the integral of effect of helper T cells over a wide range of methylprednisolone doses. This pharmacodynamic model allows flexibility for characterizing any type of steroid dosing regimen and is relevant in describing complex response data for corticosteroid immunosuppressive effects in man.     

Two-compartment basophil cell trafficking model for methylprednisolone pharmacodynamics

A two-compartment closed model was used to characterize the movement of basophils between blood and extravascular sites resulting from methylprednisolone (MP) exposure. This model is consistent with the view that corticosteroids cause a decrease in the recirculation of these cells from peripheral compartments. Methylprednisolone (Solu-Medrol) was given to healthy males at doses of 10, 25, and 40 mg. Blood samples were collected and assayed for MP by HPLC for pharmacokinetic analysis. Whole blood histamine, an index of circulating basophils, was assessed by RIA over 32 hr. Nonlinear least-squares analysis was carried out to solve for the model parameters reflecting cell movement between compartments and sensitivity (IC₅₀)to the steriod. This model quantitates the fall and return pattern of biologic response to corticosteroids with a minimal number of parameters which jointly fit several dose/response curves and yields a mean IC₅₀ value of 8.1 ng/ml similar to receptor binding of MP. Properties of the temporal and integrated response curve and model extrapolations over a wide dose range were explored with simulations. Because corticosteroids exert similar effects on other cells in blood, this model may be applicable to various regulatory and immunosuppressive effects.This work was supported in part by Grants GM 24211 and 150-1885-0 from the National Institute of General Medical Sciences, NIH.     

Evaluation of dose-related pharmacokinetics and pharmacodynamics of prednisolone in man

The pharmacokinetics and pharmacodynamics of prednisolone were evaluated in normal male volunteers. Seven subjects completed 3 phases: 16.4–and 49.2–mg iv prednisolone, and a phase with no drug to assess baseline responses. Plasma concentrations of prednisolone and urine concentrations of prednisolone and 5 metabolites were assayed by HPLC. Protein binding of prednisolone was measured by ultrafiltration. The polyexponential disposition of free and total plasma prednisolone were evaluated and apparent parameters were compared between doses. Suppression of plasma cortisol and alterations in blood basophil and helper-T cell trafficking were used as pharmacodynamic indices. Pharmacodynamic models were used to relate total or free plasma prednisolone concentrations to each of these effects generating response parameters and IC₅₀ (50% inhibitory) concentrations common to both doses. The pharmacokinetics of total drug were comparable to previous findings with CLand V_ss increasing with dose. Free prednisolone exhibited slight capacitylimited elimination and distribution as CLand V_ss decreased with the larger dose. Pharmacodynamic models jointly fitting all three phases characterized the suppression/trafficking phenomena equally well with use of total or free drug concentrations. In each case the models provided realistic values of parameters relating to steroid sensitivity-in particular IC₅₀-and to the underlying physiology of the affected systems. This study comprehensively elucidates the complexities of prednisolone pharmacokinetics and demonstrates how plasma concentration-time profiles of total or free prednisolone can be utilized for evaluation of prednisolone pharmacodynamics.Supported in part by Grants 24211 and 150-1885-0 from the National Institute of General Medical Sciences, National Institutes of Health. Presented in part at The American Society for Clinical Pharmacology and Therapeutics meeting, San Antonio, Texas. (Abstract:Clin. Pharmacol. Ther,49:179, 1991).     

Modeling Interactions between Adrenal Suppression and T-Helper Lymphocyte Trafficking during Multiple Dosing of Methylprednisolone

A physiologic pharmacodynamic model was developed to jointly characterize the effects of corticosteroid treatment on adrenal suppression and T-helper cell trafficking during single and multiple dosing in asthmatic patients. Methylprednisolone (MP), cortisol, and T-helper cell concentrations obtained from a previously published study during single day and 6 days of multiple dosing MP treatment were examined. The formation and disposition kinetics of MP were described with a compartmental model. The biorhythmic profile of basal cortisol secretion rate was analyzed using a recent Fourier approach based on circadian harmonics. A three-compartment loop model was proposed to represent three major T-helper cell pools: blood, extravascular site, and lymph nodes. T-helper cell synthesis and degradation rate constants were obtained from the literature. The suppressive effects of cortisol and MP on T-helper cell concentrations were described with a joint additive inhibition function altering the cell migration rate from lymph nodes to blood. The model adequately described both plasma cortisol profiles and T-helper cells in blood after single and multiple doses of MP. The potency of MP for suppression of cortisol secretion was estimated as IC₅₀ = 0.8 ng/ml. The biorhythmic nature of the basal T-helper cells in blood was well described as under the influence of basal circadian cortisol concentrations with IC₅₀ = 79 ng/ml. The model fitted potency of MP for suppression of T-helper cells was IC₅₀ = 4.6 ng/ml. The observed rebound of T-helper cells in blood can also be described by the proposed model. The rhythm and suppression of plasma cortisol and T-helper cells before and during single and multiple dose MP treatment were adequately described by these extended indirect response models.     

Comparison of four basic models of indirect pharmacodynamic responses

Four basic models for characterizing indirect pharmacodynamic responses after drug administration have been developed and compared. The models are based on drug effects (inhibition or stimulation) on the factors controlling either the input or the dissipation of drug response. Pharmacokinetic parameters of methylprednisolone were used to generate plasma concentration and response-time profiles using computer simulations. It was found that the responses produced showed a slow onset and a slow return to baseline. The time of maximal response was dependent on the model and dose. In each case, hysteresis plots showed that drug concentrations preceded the response. When the responses were fitted with pharmacodynamic models based on distribution to a hypothetical effect compartment, the resulting parameters were dose-dependent and inferred biological implausibility. Indirect response models must be treated as distinct from conventional pharmacodynamic models which assume direct action of drugs. The assumptions, equations, and data patterns for the four basic indirect response models provide a starting point for evaluation of pharmacologie effects where the site of action precedes or follows the measured response variable.Glossary C _e Drug concentration at the hypothetical effect site - C _p Plasma concentration of drug - C _p(T_max) Plasma concentration of drug at the time of maximal response - D Dose - EC ₅₀ Drug concentration producing 50% of maximum stimulation at effect site - E _max Maximum effect attributed to drug - E _o Baseline effect prior to drug administration - IC ₅₀ Drug concentration producing 50% of maximum inhibition at effect site - K _el First-order rate constant for drug elimination - K _eo First-order rate constant for drug loss from effect site - K _in Zero-order rate constant for production of drug response - K _out First-order rate constant for loss of drug response - n Sigmoidicity factor of the sigmoid E_max equation - R Response variable - R_max Maximal (or minimal) response - R_o Initial response (time zero) prior to drug administration - t time after drug administration - T Infusion time - T_max Time to reach maximum effect following drug administration - V Volume of distribution Supported in part by Grant No. 24211 from the National Institutes of General Medical Sciences, National Institutes of Health.     

基于拟胚体面积的体外胚胎毒性模型的建立和验证

目的 利用小鼠胚胎干细胞,以拟胚体面积为分化抑制终点,构建体外胚胎毒性模型。方法 模型建立：分别用训练集10个化合物青霉素G、异烟肼、5-氟尿嘧啶、羟基脲、阿司匹林、氟康唑、地塞米松、丙戊酸钠、洛伐他汀、苯海拉明处理小鼠胚胎干细胞ES-D3和小鼠胚胎成纤维细胞NIH/3T3 5 d,用细胞活力检测试剂盒检测细胞活性,得到相应的半数抑制浓度（IC_{50 3T3}、IC_{50 D3}）;同时用10种化合物处理ES-D3细胞,用悬浮-悬滴培养的途径制备拟胚体,于第5天对拟胚体进行拍照,用 Image J 软件测量拟胚体的横截面积,并计算半数抑制细胞分化的浓度（ID₅₀）。根据得到的 IC_{50 3T3}、IC_{50 D3}、ID₅₀,用Python软件采用线性判别分析（LDA）拟合得到线性二分类判别式。模型验证：以上述同样的方法测定测试集3个化合物维生素C、布洛芬、顺铂的IC_{50 3T3}、IC_{50 D3}、ID₅₀,将其代入得到的判别式,并预测化合物的胚胎毒性。结果 通过训练集 10个化合物拟合出线性预测判别式为：判别值＝21.550 926 58×lg IC_{50 3T3}－7.600 241 83×lg IC_{50 D3}－14.007 571 16×lg ID₅₀＋6.675 517 2,判别值＜0,归为无胚胎毒性;判别值≥0,归为胚胎毒性。将测试集化合物的 IC_{50 3T3}、IC_{50 D3}、ID₅₀代入判别式,得到维生素C判别值＜0,为无胚胎毒性药物;顺铂和布洛芬判别值＞0,为胚胎毒性药物,均与文献中体内试验结果一致,预测正确。结论 基于拟胚体面积成功建立体外胚胎毒性模型。     

Characterization of four basic models of indirect pharmacodynamic responses

Four basic models of indirect pharmacodynamic responses were characterized in terms of changing dose, I_max or S_max, and IC₅₀ or SC₅₀ to examine the effects of these fundamental drug properties on response profiles. Standard pharmacokinetic parameters were used for generating plasma concentration, and response-time profiles using computer simulations. Comparisons to theoretical expectations were made. In all four models, the maximum response (R_max) (inhibition or stimulation) and the time of its occurrence (TR_max) were dependent on the model, dose, I_max or S_max, and IC₅₀ or SC₅₀ values,. An increase in dose or a decrease in IC₅₀ or SC₅₀ by the same factor produced, as theoretically expected, identical and superimposable pharmacodynamic response patterns in each of the models. Some parameters (TR_max, ABEC) were nearly proportional to log dose, while others (R_max, CR_max) were nonlinear. Assessment of expected response signature patterns as demonstrated in this report may be helpful in experimental designs and in assigning appropriate models to pharmacodynamic data. Supported in part by Grant No. 24211 from the National Institute of General Medical Sciences, National Institutes of Health.     

Receptor-mediated methylprednisolone pharmacodynamics in rats: Steroid-induced receptor down-regulation

Several approaches to receptor down-regulation were examined to extend previous receptor/ genemediated pharmacokinetic/dynamic models of corticosteroids. Down-regulation of the glucocorticoid receptor was considered as an instantaneous event or as a gradual steroid-receptor-mediated process. Concentrations of plasma methylprednisolone, free hepatic cytosolic receptors, and the activity of hepatic tyrosine aminotransferase (TAT) enzyme were measured for 16 hr following administration of 0, 10, and 50 mg/kg methylprednisolone sodium succinate to 93 adrenalectomized rats. Receptor down-regulation was best described by a fractional decrement in the rate of return of free cytosolic glucocorticoid receptor. Predicted values for free receptor, bound receptor, nuclear bound receptor, and transfer compartments were in accord with the expected rank order values based on the high and low steroid doses. Model parameter estimates were independent of dose and described the rapid depletion of free cytosolic receptor, latephase return of cytosolic receptor to a new baseline level that was 20–40% lower than control, and the TAT induction/dissipation pattern following steroid dosing. The microscopic association and dissociation constants describing the steroidreceptor interaction were 0.23 L/nmole per hr (k_on and 4.74 hr^–1 (k_off) for methylprednisolone compared to previously obtained values of 0.20 L/nmole per hr and 15.7 hr^–1 for the related steroid prednisolone. The time course of TAT induction was similar to that observed previously for prednisolone. Efficiency of TAT induction was more closely related to steroid receptor occupancy than plasma methylprednisolone concentrations due to receptor saturability and receptor recycling.Supported in part by Grant No. 24211 from the National Institutes of General Medical Sciences, NIH, and by a Fellowship from the American Foundation for Pharmaceutical Education for D.H.     

Halofuginone suppresses T cell proliferation by blocking proline uptake and inducing cell apoptosis

Inactivation of T cells is a widely used strategy for immunosuppression. Halofuginone (HF) is an antiprotozoal agent for treating parasites in veterinary medicine, and has been demonstrated to inhibit collagen type 1 synthesis, T helper 17 cell differentiation and cytokine production in activated T cells. The present study was designed to examine the biological effects of HF against T cell receptor and interleukin (IL)-2 stimulated T cell proliferation. T cell proliferation in cultured murine splenocytes was determined by methylthiazol tetrazolium assay. Cell apoptosis was mainly determined by fluorescence-activated cell sorting with Annexin-V and 7-aminoactinomycin D staining. Here, we showed that HF significantly suppressed T cell proliferation in naïve splenocyte cultures in response to alloantigen or anti-CD3 antibody (IC₅₀, 2–2.5 nM; P < 0.0001), or in activated T cell cultures in response to IL-2 (IC₅₀, 16 nM; P < 0.0001) in a dose-dependent manner. HF did neither attenuate IL-2 production in anti-CD3 antibody activated T cells nor disrupt STAT5 signaling in IL-2-stimulated T cells, but its anti-T cell proliferation was correlated with an increase in cell apoptosis and a decrease in proline uptake in culture medium. Further experiments showed that proline supplement in cell culture medium significantly prevented HF-mediated suppression of T cell proliferation and cell apoptosis. In conclusion, these data suggest that HF interferes with proline incorporation or uptake, resulting in apoptosis via amino acid starvation response in T cells in the response to antigen/mitogen or IL-2 stimulation.     

Mathematical Assessment of Properties of Precursor-Dependent Indirect Pharmacodynamic Response Models

Precursor-dependent indirect response (PDIDR) models may describe the tolerance and rebound phenomenon observed for many pharmacodynamic responses where these characteristics are manifested due to the depletion or accumulation of a physiological precursor or cofactor pool responsible for generating drug effects. The purpose of this report is to extend the concepts and applications of these models and to approximate responses and limiting conditions for very large doses of drugs. Asymptotic analysis was performed for qualitative determination of various parameters, such as maximum response (R_max) and rebound (R_Bmax), time to maximum response and rebound (T_Rmax and TR_Bmax), and area under the effect and rebound curve (ABEC and ABRC) for large doses. Computer simulations were performed to assess the role of dose for both cases where drugs act either by depleting (Model V) or by blocking (Model VI) the endogenous precursor. Simulations showed that R_max, R_Bmax, T_RBmax, ABEC and ABRC increase with dose, eventually reaching a plateau when Dose/V is very large compared to the efficacy parameters (SC₅₀ or IC₅₀) of the drug. However, T_Rmax either increased or decreased with dose depending on various system and drug parameters. The limits for these parameters at large doses qualitatively determined by asymptotic analysis closely approximated the plateaus observed from the simulated curves. At large doses, the drug response could be approximated by a Bateman-like function for both Models V and VI. Qualitative analyses along with simulation studies provide a fundamental basis for understanding the temporal aspects of the PDIDR models especially at large doses to describe the tolerance and rebound phenomenon. Supported by Grant GM 57980 from National Institute of General Medical Sciences, National Institutes of Health.     

Anti-Elastase and Anti-Hyaluronidase Activities of Saponins and Sapogenins from Hedera helix,Aesculus hippocastanum,and Ruscus aculeatus: Factors Contributing to their Efficacy in the Treatment of Venous Insufficiency

Triterpene and steroid saponins and sapogenins of medicinal plants (Aesculus hippocastanum L., Hedera helix L., Ruscus aculeatus L.) are claimed to be effective for the treatment/prevention of venous insufficiency. In this work we evaluated the inhibitory effects of these plant constituents on the activity of elastase and hyaluronidase, the enzyme systems involved in the turnover of the main components of the perivascular amorphous substance. The results evidence that for Hedera helix L., the sapogenins only non-competitively inhibit hyaluronidase activity in a dose-dependent fashion, showing comparable IC₅₀ values (hederagenin IC₅₀ = 280.4 μM; oleanolic acid IC₅₀ = 300.2 μM); both the saponins hederacoside C and α-hederin are very weak inhibitors. The same behaviour is observed for serine protease porcine pancreatic elastase: the glycosides are devoid of inhibitory action, while genins are potent competitive inhibitors (oleanolic acid IC₅₀ = 5.1 μM; hederagenin IC₅₀ = 40.6 μM). Constituents from Aesculus hippocastanum L. show inhibitory effects only on hyaluronidase, and this activity is mainly linked to the saponin escin (IC₅₀ = 149.9 μM), less to its genin escinol (IC₅₀ = 1.65 μM). By contrast, ruscogenins from Ruscus aculeatus L., ineffective on hyaluronidase activity, exhibit remarkable anti-elastase activity (IC₅₀ = 119.9 μM; competitive inhibition). The mechanism of elastase inhibition by triterpene and steroid aglycones, with a nitroanilide derivative as substrate, is discussed.     

Dose equivalency evaluation of major corticosteroids: pharmacokinetics and cell trafficking and cortisol dynamics

The integrity of current corticosteroid dose equivalency tables, as assessed by mechanistic models for cell trafficking and cortisol dynamics, was investigated in this study. Single, presumably equivalent, doses of intravenous hydrocortisone, methylprednisolone, dexamethasone, and oral prednisolone were given to 5 white men, according to total body weight, in a 5-way crossover, placebo-controlled study. Pharmacodynamic (PD) response-time profiles for T helper cells, T suppressor cells, neutrophils, and adrenal suppression were evaluated by extended indirect response models. For adrenal suppression, prednisolone appears to be less potent than methylprednisolone or dexamethasone. A good correlation was found between the estimated in vivo EC50 values and relative receptor affinity (equilibrium dissociation constants normalized to dexamethasone). Area under the effect curves of all PD responses was calculated using a linear-trapezoidal method. Although T helper cell trafficking and adrenal suppression achieved significant differences by repeated-measures ANOVA (p = 0.014 and 0.022), post hoc analysis using the Bonferroni method revealed no difference between treatments. Although limited by the use of single doses and a relatively small sample size, this study applies mechanistic models for several biomarkers showing that currently used dosing tables reflect reasonable dose equivalency relationships for four corticosteroids.     

Structural modification of 5,7-dimethoxyflavone from <Emphasis Type="Italic">Kaempferia parviflora</Emphasis> and biological activities

5,7-Dimethoxyflavone, a major compound from Kaempferia parviflora, was used as a starting material for structural modification. Seven flavonoid derivatives have been synthesized from this flavone. Two new oxime derivatives 4 and 6 exhibited cytotoxicity against HepG2 cell line with IC₅₀ values of 36.38 and 25.34 μg/mL, respectively, and against T47D cell line with IC₅₀ values of 41.66 and 22.94 μg/mL, respectively. Compound 7 showed cytotoxicity against HepG2 and T47D cell lines with IC₅₀ values of 21.36 and 25.00 μg/mL, respectively. Compounds 6 and 7 showed cytotoxicity nearly equal to the tamoxifen standard. In addition, oxime 6 exhibited antifungal activity against Candida albicans with an IC₅₀ value of 48.98 μg/mL.     

Cytotoxicity of various chemicals and mycotoxins in fresh primary duck embryonic fibroblasts: a comparison to HepG2 cells

To screen cost‐effectively the overall toxicity of a sample, particularly in the case of food and feed ingredient quality control, a sensitive bioassay is necessary. With the wide variety of cytotoxicity assays, performance comparison between assays using different cells has become of interest. Fresh primary duck embryonic fibroblasts (DEF) were hypothesized to be a sensitive tool for in vitro cytotoxicity screening; cell viability of DEF in response to various cytotoxins was determined and compared with response of HepG2 cells. The IC₅₀ values by the alamar blue assay in the DEF cells had a high correlation (R² = 0.96) with those obtained in HepG2 cells. Within the same toxin, primary DEF yielded significantly lower IC₅₀ values than that obtained from HepG2 cells using the MTT and alamar blue assay. Additionally, primary DEF responded to all mycotoxins tested using the alamar blue assay, while HepG2 was less sensitive, particularly at short exposure times. The estimated IC₅₀ for aflatoxin B₁, fumonisins B₁ and deoxynivalenol in DEF after 72 h incubation were 3.69, 4.19 and 1.26 μg ml^–1, respectively. Results from the current study suggest that primary DEF are more sensitive to cytotoxins and mycotoxins compared to HepG2, and thus may have great potential as an effective tool for cytotoxicity assessment. The question remains whether in vitro IC₅₀ values can accurately predict in vivo toxicity; however, the current study accentuates the need for further attention to identify sensitive cell models for in vitro cytotoxicity screening and subsequent exploration of species‐specific prediction models for in vivo toxicity. Copyright © 2016 John Wiley & Sons, Ltd.     

Population Pharmacokinetic/Pharmacodynamic Modeling of Systemic Corticosteroid Inhibition of Whole Blood Lymphocytes: Modeling Interoccasion Pharmacodynamic Variability

Purpose To develop a population pharmacokinetic/pharmacodynamic (PK/PD) model that characterizes the effects of major systemic corticosteroids on lymphocyte trafficking and responsiveness. Materials and Methods Single, presumably equivalent, doses of intravenous hydrocortisone (HC), dexamethasone (DEX), methylprednisolone (MPL), and oral prednisolone (PNL) were administered to five healthy male subjects in a five - way crossover, placebo - controlled study. Measurements included plasma drug and cortisol concentrations, total lymphocyte counts, and whole blood lymphocyte proliferation (WBLP). Population data analysis was performed using a Monte Carlo-Parametric Expectation Maximization algorithm. Results The final indirect, multi-component, mechanism-based model well captured the circadian rhythm exhibited in cortisol production and suppression, lymphocyte trafficking, and WBLP temporal profiles. In contrast to PK parameters, variability of drug concentrations producing 50% maximal immunosuppression (IC₅₀) were larger between subjects (73–118%). The individual log-transformed reciprocal posterior Bayesian estimates of IC₅₀ for ex vivo WBLP were highly correlated with those determined in vitro for the four drugs (r ²  = 0.928). Conclusions The immunosuppressive dynamics of the four corticosteroids was well described by the population PK/PD model with the incorporation of inter-occasion variability for several model components. This study provides improvements in modeling systemic corticosteroid effects and demonstrates greater variability of system and dynamic parameters compared to pharmacokinetics. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Second generation model for prednisolone pharmacodynamics in the rat

An improved model describing receptor/gene-mediated pharmacodynamics of prednisolone is presented which consists of seven differential equations. Data for plasma prednisolone concentrations, free hepatic glucocorticoid receptors, and hepatic tyrosine aminotransferase activity (TAT) following low (5 mg/kg) and high (50 mg/kg) doses of prednisolone are used to quantitate the kinetics and dynamics of this synthetic steroid in the rat. In contrast to the earlier model, the newer model provides for a coupling and simultaneous fitting of receptor and TAT data and is able to describe the recycling of receptors between cytosol and nucleus and the return of cytosolic receptors to baseline following glucocorticoid elimination. A numerical technique to determine the efficiency of TAT induction based on area under the curve calculations is presented, which supports the hypothesis that nonlinear dose-response effects are due to dose and time-dependent receptor depletion in the cytosol. Simulations are presented to examine the major determinants of corticosteroid effects and to compare the effects of single-and multiple-dose regimens in maximizing drug effects.Supported in part by Grant 24211 from the National Institutes of General Medical Sciences, National Institutes of Health.     

Cytotoxic effects of Eryngium kotschyi and Eryngium maritimum on Hep2, HepG2, Vero and U138 MG cell lines

Abstract

Context: Eryngium maritimum L. and the endemic Eryngium kotschyi Boiss. of the Apiaceae family are used for antiinflammatory, antivenom, antinociceptive and diuretic purposes in folk medicine in Turkey.

Objective: This study investigated the cytotoxic effects of the plant extracts belonging to Eryngium L. genus on various cell lines.

Materials and methods: Cytotoxic activites of the lyophilized aqueous aereal and root parts of the plant extracts on human hepatocellular carcinoma (HepG2), human laryngeal epidermoid carcinoma (Hep2), human glioma (U138-MG) and African green monkey kidney epithelial (Vero) cell lines at 8.33–266.62?µg/ml concentrations were analyzed by lactate dehydrogenase (LDH) leakage and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) cell viability assays.

Results: Inhibitory concentration 50 (IC₅₀) values were found <100?µg/ml in most cases varying around 16.33–125.66?µg/ml. IC₅₀ values for E. kostchyi and E. maritimum root parts on Hep2 cells (32.86 and 30.25?µg/ml, respectively), E. kotschyi aereal, E. maritimum aereal and root parts on HepG2 cells (31.75, 32.42 and 35.01?µg/ml, respectively) by MTT assay were found to be close to the US National Cancer Institute (NCI) recommendations (IC₅₀?<?30?µg/ml) to define the antivity aganist cancer cells. The lowest IC₅₀ values according to the LDH method were observed in Hep2 cells and the highest in U138-MG cells. Root parts were found to be more toxic than aereal parts for both plants in both methods in general.

Discussion and conclusion: Both plant extracts exerted cytotoxic activity aganist Hep2 and HepG2 cells, with low IC₅₀ values defining their promising anticancer property according to NCI; however, further analysis are needed to confirm their activity.     

Synthesis and Biological Evaluation of Fluorinated 3‐Phenylcoumarin‐7‐O‐Sulfamate Derivatives as Steroid Sulfatase Inhibitors

In the present work, we report the initial results of our study on a series of 3‐phenylcoumarin sulfamate‐based compounds containing C‐F bonds as novel inhibitors of steroid sulfatase. The new compounds are potent steroid sulfatase inhibitors, possessing more than 10 times higher inhibitory potency than coumarin‐7‐O‐sulfamate. In the course of our investigation, compounds 2b and 2c demonstrated the highest inhibitory effect on the enzymatic steroid sulfatase assay; both had IC₅₀ values of 0.27 μm (the IC₅₀ value of coumarin‐7‐O‐sulfamate is 3.5 μm , used as a reference).     

Immunosuppressive efficacy of tetrandrine combined with methylprednisolone against mitogen‐activated peripheral blood mononuclear cells of haemodialysis patients

Immunosuppressive therapy for prevention of acute rejection episode occasionally causes serious adverse effects, and thus it is important to develop new therapeutic approach for renal transplant recipients. This study evaluated the immunosuppressive pharmacodynamics of tetrandrine (TET) and/or methylprednisolone (MP) in haemodialysis patients in vitro by using the peripheral blood mononuclear cells (PBMCs) isolated from whole blood of haemodialysis patients. The median (range) of MP IC₅₀ values against the proliferation of patients PBMCs was 7.04 (2.30‐500.00) ng/mL. In contrast, the median (range) of MP IC₅₀ values against the proliferation of healthy PBMCs was 4.44 (3.19‐5.08) ng/mL. The median (range) of TET IC₅₀ values against the proliferation of patients PBMCs was 1.61 (1.04‐4.79) μmol/L. Lower concentrations of TET (0.3‐300 nmol/L) were able to decrease the IC₅₀ values of MP and thus potentiate the MP immunosuppressive effect on patient PBMCs. The median (range) of MP IC₅₀ values in combination with 0.3, 3, 30, and 300 nmol/L TET were 0.92 (0.49‐8.39), 2.10 (0.45‐20.00), 0.35 (0.092‐1.05), and 0.14 (0.05‐6.78) ng/mL, respectively. TET potentiates the MP immunosuppressive pharmacodynamics and thus, it was possible to use the combination of MP and TET to attenuate MP side effects. There were significant correlations between the IC₅₀ values of TET and stimulation indices (P=0.04, r=.58), the IC₅₀ values of TET and the haemodialysis periods (P=0.04, r=.57), or the IC₅₀ values of MP combined with 0.3 nmol/L TET and C‐reactive protein concentrations (P=0.04, r=.64), respectively.