Chemical composition, antimicrobial, antioxidant and cytotoxic activity of the essential oil from the leaves of Acanthopanax leucorrhizus (Oliv.) Harms

The leaf essential oil of Acanthopanax leucorrhizus, a widely used medicinal plant, was obtained by hydrodistillation and analyzed by using combination of capillary GC-FID, GC-MS and RI. Fifty-nine components, representing 93.1% of the total oil, were identified in the essential oil and the main components of the oil were β-pinene (7.3%), linalool (6.5%), p-cymene (6.3%), β-elemene (3.8%), γ-terpinene (3.7%), spathulenol (3.2%) and cis-sabinene hydrate (3.1%). Furthermore, the in vitro antimicrobial, antioxidant and cytotoxic activities of the essential oil were examined. The test results showed that the essential oil exhibited a broad spectrum of anti-microbial activity against all microorganisms tested. Gram-positive bacteria were more sensitive to the oil than gram-negative bacteria and yeasts. The oil possessed moderate cytotoxicity on human tumor cells with lower IC(50) values of 25.65μg/ml (Hep G2), 28.71μg/ml (Hela), 30.15μg/ml (Bel-7402) and 37.55μg/ml (A-549). The moderate antioxidant activity of the oil was also evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method.     

Chromosomal instability and cytotoxicity induced by ribavirin: comparative analysis in cell lines with different drug-metabolizing profiles

Ribavirin is an important component of the treatment for hepatitis C virus (HCV) infection and, in combination with the new direct-acting antiviral (DAA) agents, comprises the major current therapeutic regimens. This study evaluated the cytotoxicity and chromosomal instability induced by ribavirin using the in vitro cytokinesis-block micronucleus cytome (CBMN-Cyt) assay in two cell lines with different expression levels of drug-metabolizing enzymes: human hepatocellular carcinoma cells (HepG2) and Chinese hamster ovary (CHO-K1) cells. HepG2 cells were treated with nine concentrations (from 15.3?μg/ml to 3.9?mg/ml) and CHO-K1 cells were exposed to eight concentrations (from 15.3?μg/ml to 1.9?mg/ml) of ribavirin for 24?h. Ribavirin inhibited cell proliferation in both cell lines, but at different concentrations: 3.9?mg/ml in HepG2 and 244.2?μg/ml in CHO-K1 cells. No significant differences were observed regarding aspects of cell death in HepG2 and CHO-K1 cells, reflecting the absence of cytotoxic effects associated to ribavirin. Ribavirin did not increase the frequency of nucleoplasmic bridges (NPBs) and nuclear bud (NBUD). However, when compared to the negative control, a significant increase in micronuclei (MNi) frequency was observed in both cell lines. However, chromosomal instability was induced by higher concentrations of ribavirin in HepG2 cells (from 61.1 to 976.8?μg/ml), compared with CHO-K1 cells (15.3 and 30.5?μg/ml). These results demonstrate the potential of ribavirin to promote chromosomal instability, and suggest that cells with different expressions of drug-metabolizing enzymes show different susceptibility to ribavirin effects.     

Cardioprotective effects of fucoidan against hypoxia-induced apoptosis in H9c2 cardiomyoblast cells

Abstract

Context: Cardiomyocyte apoptosis plays a critical role in the progress of heart diseases. Fucoidan, a complex-sulfated polysaccharide, has been reported to possess potential cardioprotective efficacy in vivo.

Objective: The present study determines whether fucoidan could provide cardioprotection on hypoxia-induced cardiomyocyte apoptosis.

Materials and methods: H9c2 cardiomyoblast cells were incubated with various concentrations (15, 30, and 60?μg/ml) of fucoidan in a humidified incubator at 37?°C with 95% O₂ and 5% CO₂. After 6?h, hypoxia was processed and the cardioprotective effects of fucoidan were evaluated by applying MTT, ELISA, Hoechst 33258 nucleus staining, and western blot.

Results: Following a 6?h exposure of H9c2 to hypoxic condition, significant reduction was found in cell survival (0.57-fold) and superoxide dismutase (SOD) activity (0.56-fold), which were associated with the increase of malondialdehyde (MDA) level (2.58-fold), creatine phosphokinase (CK, 3.57-fold), and lactate dehydrogenase (LDH) activities (2.39-fold). Moreover, hypoxia-induced apoptosis was confirmed by Hoechst 33258 nuclear staining, and these changes were accompanied by the increase of Bcl-2 (1.27-fold) and Bax expression (2.6-fold). However, preincubation of the cells with fucoidan prior to hypoxia exposure elevated the cell viability (30?μg/ml, 1.18-fold; 60?μg/ml, 1.32-fold) and SOD activity (30?μg/ml, 1.12-fold; 60?μg/ml, 1.25-fold), but decreased the MDA level (30?μg/ml, 0.70-fold; 60?μg/ml, 0.80-fold), CK (30?μg/ml, 0.69-fold; 60?μg/ml, 0.76-fold), and LDH (30?μg/ml, 0.67-fold; 60?μg/ml, 0.86-fold) leakages. Hoechst 33258 nuclear staining observations demonstrated the same protective effect of fucoidan on hypoxia-induced myocardial injury. Also, cardioprotective effects of fucoidan were reflected by increasing Bcl-2 (60?μg/ml, 1.84-fold), as well as decreasing Bax (60?μg/ml, 0.6-fold).

Conclusion: Fucoidan had protective effect against hypoxia-induced cardiomyocytes apoptosis, and the mechanism might involve protections of the cell from oxidative injury.     

5‐Arylaminouracil Derivatives: New Inhibitors of Mycobacterium tuberculosis

Three series of 5‐arylaminouracil derivatives, including 5‐(phenylamino)uracils, 1‐(4′‐hydroxy‐2′‐cyclopenten‐1′‐yl)‐5‐(phenylamino)uracils, and 1,3‐di‐(4′‐hydroxy‐2′‐cyclopenten‐1′‐yl)‐5‐(phenylamino)uracils, were synthesized and screened for potential antimicrobial activity. Most of compounds had a negative effect on the growth of the Mycobacterium tuberculosis H37Rv strain, with 100% inhibition observed at concentrations between 5 and 40 μg/mL. Of those, 1‐(4′‐hydroxy‐2′‐cyclopenten‐1′‐yl)‐3‐(4?‐hydroxy‐2?‐cyclopenten‐1?‐yl)‐5‐(4″‐butyloxyphenylamino)uracil proved to be the most active among tested compounds against the M. tuberculosis multidrug‐resistant strain MS‐115 (MIC₉₀ 5 μg/mL). In addition, the thymidylate kinase of M. tuberculosis was evaluated as a possible enzymatic target.     

Use of in vitro assays to assess the potential cytotoxic,genotoxic and antigenotoxic effects of vanillic and cinnamic acid

Vanillic acid (VA) found in vanilla and cinnamic acid (CA) the precursor of flavonoids and found in cinnamon oil, are natural plant phenolic acids which are secondary aromatic plant products suggested to possess many physiological and pharmacological functions. In vitro and in vivo experiments have shown that phenolic acids exhibit powerful effects on biological responses by scavenging free radicals and eliciting antioxidant capacity. In the present study, we investigated the antioxidant capacity of VA and CA by the trolox equivalent antioxidant capacity (TEAC) assay, cytotoxicity by neutral red uptake (NRU) assay in Chinese Hamster Ovary (CHO) cells and also the genotoxic and antigenotoxic effects of these phenolic acids using the cytokinesis-blocked micronucleus (CBMN) and the alkaline comet assays in human peripheral blood lymphocytes. At all tested concentrations, VA (0.17–67.2?μg/ml) showed antioxidant activity but CA (0.15–59.2?μg/ml) did not show antioxidant activity against 2,2-azino-bis (3-ethylbenz-thiazoline-6-sulphonic acid) (ABTS). VA (0.84, 4.2, 8.4, 16.8, 84 and 168?μg/ml) and CA (0.74, 3.7, 7.4, 14.8, 74, 148?μg/ml) did not have cytotoxic and genotoxic effects alone at the studied concentrations as compared with the controls. Both VA and CA seem to decrease DNA damage induced by H₂O₂ in human lymphocytes.     

Simultaneous determination and pharmacokinetic analysis of seven alkaloids and two flavonoids from rat plasma by HPLC-DAD after oral administration of Wuzhuyu decoction

A simple and sensitive high-performance liquid chromatographic method was developed for the simultaneous determination and pharmacokinetic analysis of seven alkaloids dehydroevodiamine (DHED), 10-hydroxyrutaecarpine (HDR), evodiamine (EDM), rutaecarpine (RCP), 1-methyl-2-n-nonyl-4(1H)quinolone (MNQ), evocarpine (ECP), and dihydroevocarpine (DHE), and two flavonoids isorhamnetin-7-O-rutinoside (RIM) and diosmetin-7-O-β-d-glucopyranoside (GRD) in rat plasma after oral administration of Wuzhuyu decoction. The flow rate was kept at 1.0?ml/min and the detection wavelength was set at 300?nm. The calibration curves were linear in the range of 0.5013-30.076?μg/ml for DHED, 0.2161-21.608?μg/ml for RIM, 0.161-12.876?μg/ml for HDR, 0.2146-21.457?μg/ml for GRD, 2.0464-40.928?μg/ml for EDM, 1.0398-31.194?μg/ml for RCP, 0.5970-35.818?μg/ml for MNQ, 0.8371-20.928?μg/ml for ECP, and 0.5167-31.003?μg/ml for DHE. The precision (relative standard deviation (RSD), %) for all was less than 10% and the accuracy (relative error (RE), %) was within ±?10%. The results demonstrated that the assay had remarkable reproducibility with acceptable accuracy and precision. The lower limit of quantifications for the compounds in plasma ranged from 0.12 to 0.23?μg/ml and the lower limit of detections ranged from 0.024 to 0.076?μg/ml. This validated method has been successfully applied in the pharmacokinetics study of seven alkaloids and two flavonoids after orally administrating the Wuzhuyu decoction to rats.     

Genotoxic evaluation of terbinafine in human lymphocytes in vitro

Terbinafine is an antimycotic drug usually used against several superficial fungal infections and with a potential application in the treatment of human cancers. Since to date there are few data on the genotoxic effects of terbinafine in mammalian cells, current study evaluated the potential genotoxic of such antifungal agent in cultured human peripheral blood lymphocytes. Terbinafine was used at the peak plasma concentration (1.0?μg/ml) and in four additional concentrations higher than the human plasmatic peak (5.0?μg/ml, 25.0?μg/ml, 50.0?μg/ml and 100.0?μg/ml). Chromosomal aberrations (CA), sister chromatid exchanges (SCE), micronuclei (MN), nucleoplasmic bridges (NP) and nuclear buds (NB) were scored as genetic endpoints. In all analysis no significant differences (α?=?0.05, Kruskal-Wallis test) were observed. Complementary criterion adopted to obtain the final response in cytogenetic agreed with statistical results. Therefore, results of this study showed that terbinafine neither induced CA, SCE, MN, NP and NB nor affected significantly mitotic, replication and cytokinesis-block proliferation indices in any of the tested concentrations. It may be assumed that terbinafine was not genotoxic or cytotoxic to cultured human peripheral blood lymphocytes in our experimental conditions.     

Genotoxicity of antiobesity drug orlistat and effect of caffeine intervention: an in vitro study

Context: Obesity is a major global health problem associated with various adverse effects. Pharmacological interventions are often necessary for the management of obesity. Orlistat is an FDA-approved antiobesity drug which is a potent inhibitor of intestinal lipases. Objective: In the current study, orlistat was evaluated for its genotoxic potential in human lymphocyte cells in vitro and was compared with that of another antiobesity drug sibutramine, presently withdrawn from market due its undesirable health effects. Caffeine intake may be an additional burden in people using anorectic drugs, therefore, further work is needed to be carried out to evaluate the possible effects of caffeine on orlistat-induced DNA damage. Materials and methods: Human lymphocytes were exposed to orlistat (250, 500 and 1000?μg/ml), sibutramine (250, 500 and 1000?μg/ml) and caffeine (25, 50, 75, 100, 125 and 150?μg/ml) to assess their genotoxicity by comet assay in vitro. In addition, lymphocytes were co-incubated with caffeine (50, 75 and 100?μg/ml) and a single concentration of orlistat (250?μg/ml). Results: Orlistat and sibutramine were genotoxic at all concentrations tested, sibutramine being more genotoxic. Caffeine was found to be genotoxic at concentrations 125?μg/ml and above. Co-treatment of orlistat with non-genotoxic concentrations (50, 75 and 100?μg/ml) of caffeine lead to a decrease in DNA damage. Discussion and conclusion: Orlistat can induce DNA damage in human lymphocytes in vitro and caffeine was found to reduce orlistat-induced genotoxicity.     

In vitro assessment of selected Korean plants for antioxidant and antiacetylcholinesterase activities

Context: Antiacetylcholinesterase (AChE) drugs have been a main therapeutic treatment for Alzheimer’s disease because increased AChE levels play a key role in reducing neurotransmission.

Objectives: Extracts from 35 Korean plants were selected and screened for antioxidant and anti-cholinesterase activity to explore new sources derived from Korean natural resources that could be used as AD therapeutic agents.

Materials and methods: The antioxidant effect of extracts from 35 selected Korean plants was determined using two most common free radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS). Additionally, the effect of extracts, identified as antioxidants, on acetylcholinesterase inhibition was assessed by an acetylcholinesterase assay kit.

Results: Out of 36 extracts of 35 plants tested, Oenothera biennis L. (9.09?μg/mL), Saururus chinensis (Lour.) Baill. (9.52?μg/mL) and Betula platyphylla var. japonica (9.85?μg/mL) showed strong DPPH scavenging activity. Twelve other extracts also exerted moderate free radical scavenging activities with IC₅₀ values ranging from 10 to 50?μg/mL. Antioxidant capacity detected by ABTS assay was only significant in O. biennis (23.40?μg/mL), while the other extracts were weak or unable to reduce the production of ABTS. Based on the antioxidant activities of these plant extracts, 19 extracts with IC₅₀ values less than 100?μg/mL in DPPH assay were selected for further AChE inhibition assay. Among the extracts tested, the IC₅₀ value for Prunella vulgaris var. lilacina NAKAI (18.83?μg/mL) in AChE inhibitory activity was the lowest, followed by O. biennis (20.09?μg/mL) and Pharbitis nil Chosy (22.79?μg/mL).

Conclusions: Considering complex multifactorial etiology of AD, the extracts of P. vulgaris var. lilacina (aerial part), O. biennis (seed) and P. nil (seed) may be safe and ideal candidates for future AD modifying therapies.     

Bioactive potential of endophytic Myrothecium sp. isolate M1-CA-102, associated with Calophyllum apetalum

Context: Endophytes colonizing medicinal plants are diverse, constituting a rich bioresource for novel natural products.

Objective: Myrothecium sp. isolate M1-CA-102 was the most promising among the 16 Myrothecium isolates screened. The bioactive potential of the crude extract from the Calophyllum apetalum Willd. endophytic Myrothecium sp. (Alb. &; Schwein.) Ditmar (Incertae sedis) isolate M1-CA-102 and its thin layer chromatography (TLC) fractions were screened based on antioxidant, anti-inflammatory, antimicrobial activities, and cytotoxicity.

Materials and methods: The antioxidant activity was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging capacities. Further, 15-lipoxygenase (15-LOX) and human cyclooxygenase-2 (COX-2) inhibition were assessed at different concentrations (25, 50, and 100?μg/mL for the crude extract, 5, 25, and 50?μg/mL for the TLC fractions). DNA-nicking assay as an indicator of the capacity of extracts to scavenge hydroxyl radical was recorded at a concentration of 50?μg/mL. Cell cytotoxicity was recorded by colorimetric 3-(4,5-dimethylthylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Antibacterial (Bacillus subtilis) and anti-Candida (Candida albicans) assays were performed by the microdilution method.

Results: The DPPH and ABTS IC₅₀ values of M1-CA-102 extract were 10 and 6?μg/mL compared with 6.1 and 7.03?μg/mL for the positive control quercetin. The cytotoxicity IC₅₀ value of M1-CA-102 extract was 37?μg/mL, while the M-I TLC fraction was 21?μg/mL. The M1-CA-102 extract gave an IC₅₀ value of 58 and 8?μg/mL for 15-LOX and COX-2, respectively. The MIC values for antimicrobial activity for M1-CA-102 extract ranged from 35 to 54?μg/mL, while for the TLC fractions, it ranged from 91 to 515?μg/mL.

Conclusion: The results indicate that Myrothecium M1-CA-102 isolated from C. apetalum is a potential source of natural metabolites of pharmaceutical importance.     

Chemical constituents from the roots of Feroniella lucida

A new furanocoumarin named lucidafuranocoumarin A (7) together with 13 known coumarins (1-6, 8-14) and four known alkaloids (15-18) was isolated from the roots of Feroniella lucida. Their structures were elucidated on the basis of spectroscopic analysis. Some of the isolates were evaluated for their biological activities, and compound 18 showed strong cytotoxicity against KB (IC(50)?=?0.637?μg/ml) and NCI-H187 (IC(50)?=?0.094?μg/ml) human cancer cell lines, antimalarial activity against Plasmodium falciparum (IC(50)?=?0.336?μg/ml), and antituberculosis activity against Mycobacterium tuberculosis (MIC?=?6.25?μg/ml).     

C-Geranylated flavonoids from Paulownia tomentosa fruits with antimicrobial potential and synergistic activity with antibiotics

Context C-6-Geranylated flavonoids possess promising biological activities. These substances could be a source of lead compounds for the development of therapeutics.

Objective The study was designed to evaluate their antibacterial and antileishmanial activity.

Materials and methods C-6-Geranylated flavanones were tested in micromolar concentrations against promastigote forms of Leishmania brazilensis, L. donovani, L. infantum, and L. panamensis against methicillin-resistant Staphylococcus aureus (MRSA); and synergistic potential with antibiotics was analyzed. IC₅₀ values (after 72?h) were calculated and compared with that of miltefosine. Flow cytometry and DNA fragmentation analysis were used the mechanism of the effect. Geranylated flavanones or epigallocatechin gallate were combined with oxacillin, tetracycline, and ciprofloxacin, and the effects of these two-component combinations were evaluated. Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) were established (after 24?h), the synergy was measured by the checkerboard titration technique, and the sums of the fractional inhibitory concentrations (∑FICs) were computed.

Results 3′-O-Methyl-5′-O-methyldiplacone and 3′-O-methyldiplacone showed good antileishmanial activities (IC₅₀ 8–42?μM). 3′-O-Methyl-5′-hydroxydiplacone activates the apoptotic death at leishmanias, the effect of 3′-O-methyl-5′-O-methyldiplacone has another mechanism. The test of the antibacterial activity showed good effects of 3′-O-methyldiplacol and mimulone against MRSA (MIC 2–16?μg/mL), and in six cases, the results showed synergistic effects when combined with oxacillin. Synergistic effects were also found for the combination of epigallocatechin gallate with tetracycline or oxacillin.

Conclusion This work demonstrates anti-MRSA and antileishmanial potential of geranylated flavanones and uncovers their promising synergistic activities with antibiotics. In addition, the mechanism of antileishmanial effect is proposed.     

Genotoxic effects of 4-methylimidazole on human peripheral lymphocytes in vitro

4-Methylimidazole (4-MEI), a heterocyclic organic chemical compound, is widely found in many foods and consumed by people worldwide. In this research, we aimed to investigate the cytotoxic and genotoxic effects of 4-MEI on human lymphocytes. For this purpose, human peripheral blood lymphocytes were treated with four concentrations of 4-MEI (300, 450, 600 and 750?μg/ml) for 24?h and 48?h periods and in vitro sister chromatid exchange (SCE), chromosome aberration (CA) and micronucleus (MN) tests were used. 4-MEI induced SCE in human peripheral lymphocytes at three highest concentrations (450, 600 and 750?μg/ml) in 48?h treatment period. CA and MN were induced in human peripheral lymphocytes at two highest concentrations of 4-MEI (600 and 750?μg/ml) in 24?h and 48?h treatment periods. The highest concentration of 4-MEI (750?μg/ml) induced MN formation more than the positive control MMC in 24?h treatment period. In addition, 4-MEI led to a decrease in MI at the highest concentration (750?μg/ml) in 24?h treatment period and at all concentrations in 48?h treatment period. 4-MEI reduced PI at all concentrations in 24?h treatment period and at all concentrations (expect the lowest) for 48?h treatment period. 4-MEI reduced nuclear division index (NDI) at 24 and 48?h treatment periods, even at the highest two concentrations, decreased more than the positive control MMC. Our results showed that 4-MEI pose a genotoxic and cytotoxic effects for human peripheral lymphocytes.     

Propoxur-induced oxidative DNA damage in human peripheral blood mononuclear cells: protective effects of curcumin and α-tocopherol

The present study enumerates the attenuating effects of curcumin and α-tocopherol against propoxur induced oxidative DNA damage in human peripheral blood mononuclear cells (PBMC). Cultured cells were isolated from peripheral blood of healthy volunteers, and were exposed to varying concentrations of propoxur (0–21?μg/ml) for 6, 12, and 24?h, and in combination with curcumin (9.2?μg/ml) or α-tocopherol (4.3?μg/ml) or both. Cytotoxic effect of propoxur was examined by MTT assay. The role of oxidative stress beneath the cytotoxicity of propoxur was evaluated by the measurement of reduced glutathione (GSH), malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OH-dG) levels in cell lysate. A concentration-dependent cell death, depletion of GSH, an increase in the level of both MDA and 8-OH-dG were observed. Co-treatment with curcumin or α-tocopherol significantly attenuates depleted GSH, decrease in MDA and 8-OH-dG levels in propoxur exposed cells (p?相似文献   

反相高效液相色谱法测定小鼠血浆中醋酸洗必泰浓度

目的 :建立小鼠血浆中醋酸洗必泰浓度的反相高效液相色谱测定法。方法 :以十二烷基磺酸钠为反离子 ,安定为内标 ,采用离子对萃取法对血样进行提取 ;μ-BondapakC18 柱 (3 9mm×300mm ,10μm)为分析柱 ,0 02mol/L磷酸二氢钾缓冲液 (pH=3)∶甲醇(44:56 ,V/V)为流动相 ,检测波长为257nm。结果 :醋酸洗必泰在0 5～10μg/ml血药浓度范围内 ,浓度与峰面积比值间线性关系良好 ,r=0 9997 ;3种血浆浓度 (1、4、8μg/ml)平均回收率为104 67 % ,日内、日间精密度分别为1 5 %、0 37 %、0 26 %及2 45 %、0 46 %、1 27 % ;血浆中药物的最低检测浓度为0 4μg/ml。结论 :该方法灵敏、准确 ,适用于临床药代动力学的研究。     

In vitro antioxidant activities of resveratrol,cinnamaldehyde and their synergistic effect against cyadox-induced cytotoxicity in rabbit erythrocytes

This study was conducted to explore the potential benefits of using cinnamaldehyde (CIN), resveratrol (RES) separately or in combination on cyadox (CYA)-induced alterations in isolated rabbit erythrocytes. Erythrocytes suspensions were partitioned into 7 groups (5 replicates/group), 1st kept as control treated with phosphate buffered saline (PBS) with dimethyl sulphoxide (DMSO); 2nd group was subjected to CYA (40?μg/ml), 3rd group was incubated with CIN (40?μM), 4th group was subjected to RES (40?μM), 5th group was co-exposed to CYA (40?μg/ml) and CIN (40?μM), 6th group was co exposed to CYA (40?μg/ml) and RES (40?μM), and 7th group was exposed to CYA in combination with both CIN and RES at the same indicated concentrations. The reaction mixtures of different groups were incubated at 37?°C for 3?h with gentle shaking every 15?minutes. Our results revealed that exposure to CYA caused a significant decrease (linear and quadratic) in superoxide dismutase (SOD) and catalase (CAT) activities and the contents of reduced glutathione (GSH) and glutathione transferase (GST). Incubation of erythrocytes with CYA increased GSSG content, GSSG/GSH ratio, malonaldehyde (MDA) and protein carbonyl (PrC) concentrations while it decreased the total protein (TP). CYA also lead to hemolysis and energy depletion of erythrocytes beside activation of caspase cascades, suggesting the pro-oxidant effect CYA that could be implicated in eryptosis. CIN and RES were able to inverse these hazardous effects of CYA. However, CIN was more effective than RES, their combination showed a positive synergistic effect in protecting the cells against oxidative injury caused by CYA.     

Inhibitory effect of six herbal extracts on CYP2C8 enzyme activity in human liver microsomes

Abstract

1.?Herbal supplements widely used in the US were screened for the potential to inhibit CYP2C8 activity in human liver microsomes. The herbal extracts screened were garlic, echinacea, saw palmetto, valerian, black cohosh and cranberry. N-desethylamodiaquine (DEAQ) and hydroxypioglitazone metabolite formation were used as indices of CYP2C8 activity.

2.?All herbal extracts showed inhibition of CYP2C8 activity for at least one of three concentrations tested. A volume per dose index (VDI) was calculated to determine the volume in which a dose should be diluted to obtain IC₅₀ equivalent concentration. Cranberry and saw palmetto had a VDI value >5.0?l per dose unit, suggesting a potential for interaction.

3.?Inhibition curves were constructed and the IC₅₀ (mean?±?SE) values were 24.7?±?2.7?μg/ml for cranberry and 15.4?±?1.7?μg/ml for saw palmetto.

4.?The results suggest a potential for cranberry or saw palmetto extracts to inhibit CYP2C8 activity. Clinical studies are needed to evaluate the significance of this interaction.     

Uptake and metabolism of mizoribine,an immunosuppressant,in L5178Y-R mouse lymphoma cells in vitro and peripheral blood mononuclear cells of rats and kidney transplant recipients in vivo

The cellular uptake of mizoribine (MZR), an immunosuppressant, and metabolism of MZR to MZR-5′- monophosphate (MZRP), an active metabolite, were evaluated in L5178Y-R mouse lymphoma cells and peripheral blood mononuclear cells (PBMCs) of rats and kidney transplant recipients (KTRs, n = 22). Real-time PCR analysis revealed the expression of ENT1 and ENT2 mRNAs, but not of CNTs, in L5178Y-R cells and rat's PBMCs. In L5178Y-R cells, the uptake of MZR was suppressed by adenosine, a substrate for ENT1 and ENT2, but not by 5-(4-nitrobenzyl)-6-thioinosine (0.1 μM), an ENT1 inhibitor. Saturable metabolism of MZR to MZRP was observed. In rats, peak plasma concentrations of MZR and peak concentrations of MZR and MZRP in PBMCs were observed 3 h after oral administration. MZR disappeared from PBMCs in parallel with plasma MZR, but the disappearance of MZRP from PBMCs appeared to be slow. In KTRs, the mean plasma concentration of MZR 3–4 h after ingestion was 3.14 μg/ml and the mean MZRP concentration in PBMCs was 16.8% of MZR, reflecting the involvement of ENT in the uptake of MZR. A linear relationship was observed between plasma MZR concentrations ranging from 1 to 6 μg/ml and PBMC's MZRP concentrations ranging from 90 to 200 ng/ml.     

Renal dysfunction in a renal transplant patient treated concurrently with cyclosporine and imatinib

Imatinib mesylate has proven activity in treating locally advanced or metastatic gastrointestinal stromal tumors (GIST). Drug interactions are particularly concerning as imatinib is extensively metabolized by the cytochrome P450 enzyme system. We describe the clinical course of a 72?year-old male with a cadaveric renal transplant requiring cyclosporine that presented with a metastatic GIST and was started on imatinib at the standard dose of 400?mg daily. Imatinib initiation resulted in a decline in renal function with the serum creatinine increasing from 123?μmol/L to 196?μmol/L and an elevation in whole blood cyclosporine concentrations from 79?μg/L to 139?μg/L. No other imatinib toxicities were reported. With discontinuation of imatinib, the serum creatinine returned to baseline as did the whole blood cyclosporine levels. Ultimately, decreasing both the cyclosporine and imatinib dosing was associated with stabilized renal function (serum creatinine 150-186?μmol/L) and cyclosporine concentrations (53-97?μg/L). A prolonged partial response to therapy for 19?months was maintained despite low imatinib trough concentrations measured on two separate occasions (127.1?ng/ml and 139?ng/ml). In our patient, imatinib initiation resulted in renal toxicity most likely due to its interaction with cyclosporine resulting in elevation of the whole blood cyclosporine concentration.     

抗新型冠状病毒卵黄抗体对病毒及变异株的体外中和作用

目的 研究抗新型冠状病毒（severe acute respiratory syndrome coronavirus 2，SARS-CoV-2）卵黄抗体（egg yolk immunoglobulin，IgY）在体外对SARS-CoV-2及其变异株的中和抑制作用，探讨其作为鼻腔/口腔喷雾剂用于预防和阻断SARS-CoV-2感染的可能性。方法 采用间接ELISA检测抗SARS-CoV-2 IgY原液及成品对刺突（spike，S）蛋白的抗体效价；用微量细胞病变法检测其对SARS-CoV-2的中和活性；用萤光素酶发光法检测其对SARS-CoV-2假病毒的中和作用。结果 抗SARS-CoV-2 IgY原液的抗S抗原效价为1:32 000~1:64 000，成品的效价为1:16 000~1:32 000；两批原液对活病毒的中和效价分别为1:128和1:256，相应的抑制中浓度（median inhibitory concentration，IC₅₀）分别为36.22和36.50 μg/ml；成品对SARS-CoV-2假病毒的IC₅₀均值分别为4.571 μg/ml（WT）和6.07 μg/ml（D614G）；对变异株假病毒的IC₅₀分别为15.09~29.94 μg/ml（B.1.1.7）、41.71~55.56 μg/ml（B.1.351）和16.66~32.33 μg/ml（B.1.617.2）。结论 抗SARS-CoV-2 IgY与SARS-CoV-2重组S蛋白具有良好的结合活性，在体外能显著地中和SARS-CoV-2活病毒、假病毒及变异株假病毒，有望用于SARS-CoV-2感染的预防和阻断。