RGD修饰的多柔比星脂质体的制备及体外抗肿瘤活性

合成了胆固醇-聚乙二醇-RGD (CHOL-PEG 2000-RGD),并经1H NMR确证结构.采用pH梯度法制备多柔比星脂质体,再以上述RGD衍生物为配体以后插入法制备RGD修饰脂质体.所得制品平均粒径为(122.5±2.8) nm,ζ电位为(-18.35±0.78) mV,包封率为(95.23±1.14)％,透射电镜显示脂质体形态为类球体.对黑素瘤细胞B16的体外生长抑制试验结果显示,原药、未修饰及经RGD修饰的多柔比星脂质体的IC50分别为0.264、0.191和0.106 μg/ml.且经RGD修饰的空白脂质体并无明显的细胞抑制作用.     

叶酸修饰多柔比星聚合物胶束的制备及体外抗肿瘤活性评价

合成了叶酸-聚乙二醇-二硬脂酰磷脂酰乙醇胺(Folate-PEG-DSPE),并用其作为靶向肿瘤的功能性材料,以甲氧基聚乙二醇-二硬脂酰磷脂酰乙醇胺(MPEG-DSPE)作为骨架材料,采用成膜水化法制备载多柔比星(1)胶束。所得胶束呈球状结构,粒径为(20±5)nm,叶酸修饰和非叶酸修饰胶束的包封率和载药量分别为(78.8±1.52)%、(79.2±147)%和(1 3.6±1.26)%、(1 3.9±1.19)%。流式细胞结果显示,分别给予游离罗丹明B(Rh B)、叶酸修饰和非叶酸修饰的载RhB胶束,摄取荧光的巨噬细胞分别占细胞总数的36.6%、1.5%和4.4%,说明聚合物胶束可显著减弱巨噬细胞的吞噬作用。体外抗KB人口腔上皮癌细胞活性的试验结果显示,1、叶酸修饰和非叶酸修饰胶束的IC_(50)分别为29 7、0.61和4.12μmol/L,表明叶酸修饰的聚合物胶束能显著提高1的抗肿瘤活性。     

Absorption,Distribution, Metabolism,and Excretion of N-Octylbicycloheptene Dicarboximide (MGK 264) Administered Orally to Rats

Abstract

Experiments were conducted in four groups of rats to determine the absorption, distribution, metabolism, and excretion (ADME) patterns following oral administration of [hexyl-1-¹⁴C] N-octylbicycloheptene dicarboximide (MGK 264).

Ten rats (five males and five females) were used in each of the four experiments. Fasted rats were administered fhexyl-1-¹⁴C] MGK 264 at a single oral dose of 100 mg/kg, at a single oral dose of 1000 mg/kg, and at a daily oral dose of 100 mg/kg of nonradiolabeled compound for 14 days followed by a single dose of ¹⁴C-labeled compound at 100 mg/kg. Rat blood kinetics were determined in the fourth group following a single oral dose of 100 mg/kg. Each animal was administered 18-30 μCi radioactivity.

Urine and feces were collected for all groups at predetermined time intervals. Seven days after dose administration, the rats were euthanized and selected tissues and organs were harvested. Samples of urine, feces, and tissues were subsequently analyzed for ¹⁴C content.

In the blood kinetics study, radioactivity peaked at approximately 4 h for the males and 6 h for the females. The decline of radioactivity from blood followed a monophasic elimination pattern. The half-life of blood radioactivity was approximately 8 h for males and 6 h for females.

Female rats excreted 71.45-73.05% of the radioactivity in urine and 20.87-25.28% in feces, whereas male rats excreted 49.49-63.49% of the administered radioactivity in urine and 31.76-46.67% in feces. Total tissue residues of radioactivity at 7 days ranged from 0.13 to 0.43% of the administered dose for all dosage regimens. The only tissues with ¹⁴C residues consistently higher than that of plasma were the liver, stomach, intestines, and carcass. The total mean recovered radioactivity of the administered dose in the studies ranged between 93.1 and 97.4%. No parent compound was detected in the urine.

Four major metabolites and one minor metabolite were isolated from the urine by high-performance liquid chromatography (HPLC) and identified by gas chromatography/mass spectometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS). The four major metabolites were shown to be carboxylic acids produced by either ω-1 oxidation or β-oxidation of the side chain and oxidation of the norbornene ring double bond. The minor metabolite was the carboxylic acid of the intact norbornene ring.

The gender of the animals affected the rate, route of excretion, and metabolic profile. The urinary excretion rate was faster in females than in males and the amount excreted was also greater in female rats.     

Diffusion and Metabolism of Prednisolone Farnesylate in Viable Skin of the Hairless Mouse

The diffusion and metabolism of prednisolone 21-farnesylate were investigated in viable skin of the hairless mouse in vitro. The pro-drug ester was extensively metabolized in viable skin, while it was stable in the donor and receptor solutions. The rate of appearance of the prodrug and its metabolite prednisolone was markedly influenced by the direction of the skin placed between the in vitro diffusion half-cells. The rate of bioconversion of the prodrug was determined as a function of the distance from the surface of the skin. The prodrug was increasingly metabolized with the distance from the surface of the skin, indicating that the responsible enzymes are enriched in the lower layers of the viable skin. A model with linearly increasing enzyme activity in the viable skin accounts for the in vitro profiles of the diffusion/metabolism of the prodrug in the viable skin of hairless mouse.     

Absorption and Presystemic Metabolism of Nefazodone Administered at Different Regions in the Gastrointestinal Tract of Humans

Purpose. The absorption and disposition of nefazodone (NEF) and its metabolites hydroxynefazodone (HO-NEF), m-chlorophenylpiperazine (mCPP) and triazole dione (dione) were assessed in 10 healthy subjects following infusion of NEF solution into the proximal and distal regions of the intestine vs administration of NEF solution orally by mouth. Methods. NEF HC1 (400 mg) was infused over 5 hours into the proximal or distal intestine through a nasogastric tube, or orally ingested in 10 divided doses over 4.5 hours. The three treatments in the three-period crossover design were separated by one week. Results. The bioavailability of NEF, based on AUC(INF), from proximal and distal regions relative to that from oral administration was 97% and 106%, respectively. NEF was absorbed equally well from all three treatments with median Tmax of 5.0 hours which coincided with the duration of infusion. Mean Cmax of NEF was not different between proximal and oral administrations, however, mean Cmax after distal instillation was 40% lower than that after oral administration. Exposure to HO-NEF, mCPP and dione, following proximal instillation was also comparable to that after oral administration. AUC(INF) of HO-NEF and dione was significantly lower after distal instillation compared to that after oral administration but AUC(INF) of mCPP was not. Cmax of all metabolites was significantly lower after distal administration in comparison to oral treatment. Terminal half-life for NEF, HO-NEF and mCPP after distal administration was longer than the other two treatments. Conclusions. NEF is absorbed throughout the length of the gastrointestinal tract which supports the development of an extended-release formulation of NEF. The exposure to the metabolites (relative to NEF) was lower from the distal intestinal site compared to the proximal and oral site which may be explained by a reduced first pass of NEF by the cytochrome P450 3A4 in the distal intestine.     

Pala Versus Streptozotocin, Doxorubicin, and Meccnu in the Treatment of Patients With Advanced Pancreatic Carcinoma

Seventy-three eligible, chemotherapy-naive, ambulatory patients with advanced pancreatic carcinoma were allocated to one of two treatment regimens: 35 received PALA (1250 mg/m² daily × 5 every 4 weeks) and 38 were given SAM (streptozotocin 400 mg/m² IV daily × 5, doxorubicin 45 mg/m² IV on day 1 and 22, and methyl CCNU 60 mg/m² orally on days 1 and 22 every 6 weeks). Doses were modified for myelo-, gi-, or cardiotoxicity. Adequate organ, bone marrow and cardiac function; a measurable lesion; adequate caloric intake; and a life expectancy of 2 months were required for treatment on this trial. One patient on each regimen had a partial response for response rates of 3% (95% confidence intervals, 0.08 to 17%). Median survival on the PALA arm was 5 months and median time to treatment failure was 2.6 months. SAM patients experienced median overall and progression free survivals of 3.4 and 1.9 months, respectively. The severe toxicity observed was almost exclusively myelosuppression on both regimens. One patient receiving SAM had lethal leukopenic sepsis during the first cycle as the only treatment-related death. Neither PALA nor SAM offer any therapeutic utility to patients with advanced pancreatic cancer.     

Tissue Distribution and Metabolism of Benzo[a]pyrene in Embryonic and Larval Medaka (Oryzias latipes)

The need to understand chemical uptake, distribution, and metabolismin embryonic and larval fish derives from the fact that theseearly life stages often exhibit greater sensitivity to xenobioticcompounds than do adult animals. In this study, a 6-h acutewaterborne exposure immediately after fertilization was usedto quickly load the egg with benzo[a]pyrene (BaP). This exposurewas used to mimic the initial egg concentration of a persistentbioaccumulative toxicant that could result from maternal transfer.We used multiphoton laser scanning microscopy (MPLSM) in combinationwith conventional analytical chemistry methods to characterizethe tissue distribution of BaP and its principal metabolitesin medaka embryos and post-hatch larvae. Embryonic metabolismof BaP was evident by MPLSM prior to liver formation or heartdevelopment. A major product of this metabolism was identifiedby liquid chromatography/mass spectrometry as BaP-3-glucuronide.MPLSM showed that metabolites were sequestered within the yolk,biliary system, and gastrointestinal tract. When the gastrointestinaltract became patent a few days after hatch, the metaboliteswere rapidly eliminated. These findings indicate that some ofthe earliest embryonic tissues are metabolically competent andthat redistribution of BaP and its metabolic products occursthroughout development. Rapid metabolism of BaP substantiallyreduces the body burden of parent chemical in the developingembryo, potentially reducing toxicity. It remains unclear whethermetabolism of BaP in medaka embryos leads to the formation ofDNA adducts associated with genotoxic effects or yields metabolitesthat later lead to other toxicity in juveniles or adults.     

不同性别小鼠体内锌—65的代谢(英文)

本文观察了不同性别小鼠体内锌-65的吸收、分布和廓清,雄性小鼠对锌-65的吸收(72±4％)显著高于雌性小鼠(56±4％);体内锌-65的分布未见性别的影响;体内锌65的滞留呈三项指数函数,而器官内呈二项指数函数,锌-65在雄性小鼠心脏和股骨内的廓清显著慢于雌性小鼠(p<0.01)。本文计算了摄入相等量锌-65的内剂量相对值,雄性小鼠是雌性小鼠的1～3倍。     

Pharmaceutical and biological properties of doxorubicin encapsulated in liposomes (L-ADM): The effect of repeated administration on the systemic phagocytic activity and pharmacokinetics

We investigated the biodistribution and antitumour activity of doxorubicin (ADM) encapsulated in liposomes (L-ADM) after two administrations in tumour bearing mice. The effect of the first administration on phagocytic activity was also examined. The biodistribution of L-ADM after the second dosing at an interval of 4d was remarkably different from that after the first. The concentration of ADM in plasma and tumour after the second injection was higher, but that in the liver was lower than after the first administration. This decrease in distribution to the liver is thought to have contributed to the difference in the biodistribution characteristics of L-ADM. With regard to antitumour effect, the activity was similar between L-ADM and a solution of ADM (F-ADM). To investigate the effect of the first administration of L-ADM on biodistribution, systemic phagocytic activity was measured after the injection of F-ADM, L-ADM, or ‘empty’ liposomes not containing ADM. F-ADM and L-ADM (7.5 mg ADM/kg body weight) reduced phagocytic activity to approximately 50% and 30% of control, respectively. This finding suggests that entrapment of ADM in liposomes enhances both the distribution of the drug to the reticuloendothelial system (RES) and its suppressive effect on RES activity. These results indicate that the decrease in RES activity by L-ADM must be considered in estimation of the pharmacokinetics, antitumour activity, and toxicity of L-ADM in clinical use when given by repeat administration or used in combination with other antitumour agents.     

3,4-甲撑二氧去氧麻黄碱在生物体内的立体选择性代谢

采用立体选择性分析方法测定了3,4－甲撑二氧去氧麻黄碱在大鼠和小鼠体内0～96h的排泄量。结果表明药物及其代谢物对映体呈现立体选择性的代谢。药物的S－（＋）－对映体在N－脱甲基代谢途径中占优势（S／R=1．61）,R－（－）-对映体则在O-脱烃基代谢途径中占主导地位（R／S＝1.28）。毒性大的S－（＋）－对映体代谢较慢;该药物的主体选择性代谢具有种属差异。     

Differences in the Intracellular Distribution of Acid-Sensitive Doxorubicin-Protein Conjugates in Comparison to Free and Liposomal Formulated Doxorubicin as Shown by Confocal Microscopy

Purpose. To investigate differences in the cellular uptake and intracellular distribution of protein-bound doxorubicin in comparison to free doxorubicin and a liposomal formulation (CAELYX®) Methods. LXFL 529 lung carcinoma cells were incubated with an acid-sensitive transferrin and albumin conjugate of doxorubicin, a stable albumin doxorubicin conjugate, and free and liposomal doxorubicin for up to 24 h. The uptake of doxorubicin was detected with confocal laser scanning microscopy (CLSM). To investigate the intracellular localization of the anticancer drug, lysosomes, Golgi apparatus, and mitochondria were also stained by various organelle-specific fluorescent markers. In vitro efficacy of the doxorubicin derivatives was examined with the BrdU incorporation assay. Results. The acid-sensitive albumin and transferrin doxorubicin conjugates showed enhanced cytotoxicity in comparison to liposomal doxorubicin, whereas the stable albumin-doxorubicin conjugate showed only marginal activity. Of all compounds tested, doxorubicin showed the highest cytotoxicity. CLSM studies with specific markers for lysosomes, mitochondria, and the Golgi apparatus demonstrated that protein-bound doxorubicin or liberated doxorubicin was accumulated in the mitochondria and Golgi compartments, but not in the lysosomes after 24 h. Free doxorubicin showed a time-dependent intracellular shift from the nucleus to the mitochondria and Golgi apparatus. Fluorescence resulting from incubation with CAELYX was primarily detected in the nucleus. Conclusions. Our results indicate that other organelles in addition to the cell nucleus are important sites of accumulation and interaction for protein-bound doxorubicin or intracellularly released doxorubicin as well as for free doxorubicin.     

Characterization of Esterase and Alcohol Dehydrogenase Activity in Skin. Metabolism of Retinyl Palmitate to Retinol (Vitamin A) During Percutaneous Absorption

Retinyl palmitate, a widely used ingredient in cosmetic products, is promoted for its beneficial effects on the appearance of skin. Previous studies suggest that enzymes are available in skin to metabolize this ingredient during skin absorption. Esterase activity hydrolyzes retinyl palmitate to retinol (vitamin A), which is oxidized in many tissues to retinoic acid primarily by alcohol dehydrogenase. The activities of esterase and alcohol dehydrogenase were characterized in hairless guinea pig skin by using flow-through diffusion cells and radiolabeled model compounds (methyl salicylate and benzyl alcohol) previously shown to be metabolized by these enzymes. Methyl salicylate was hydrolyzed by esterase to a greater extent in viable skin than in nonviable skin. Glycine conjugation of salicylic acid and benzoic acid occurred only in viable skin. The metabolism of methyl salicylate and benzyl alcohol occurred to a greater extent in male guinea pig skin than in female guinea pig skin. The percutaneous absorption of both radiolabeled compounds was similar in viable and nonviable skin. About 30 and 18% of topically applied retinyl palmitate were absorbed from an acetone vehicle by hairless guinea pig skin and human skin, respectively. Less than 1% of the applied dose of this lipophilic compound diffused from skin into the receptor fluid. Retinol was the only detectable metabolite of retinyl palmitate in both hairless guinea pig and human skin. In human skin, 44% of the absorbed retinyl palmitate was hydrolyzed to retinol. The use of retinyl palmitate in cosmetic formulations may result in significant delivery of retinol into the skin.James Boehnlein: Results submitted as partial fulfillment of requirements for the M.S. in Pharmaceutical Science degree (Cosmetic Science),     

Activity of Antioxidative Enzymes in Erythrocytes after a Single Dose Administration of Doxorubicin in Rats Pretreated with Fullerenol C60(OH)24

In earlier in vitro investigations, fullerenol was shown to have a strong antioxidative capability. The present study examined the role of fullerenol as a potential antioxidative protector for doxorubicin-induced oxidative stress in the blood of rats through an investigation of the activity of glutathione-dependent enzymes (glutathione-S-transferase and glutathione peroxidase). It also assessed the influence of fullerenol on the number of blood cells (leukocytes and erythrocytes) as well as on the content of hemoglobin after a single dose administration of doxorubicin. Experiments were performed on six groups of adult male Wistar rats, each group containing eight individuals. Doxorubicin was administrated i.v. (tail vein) in a single dose of 10 mg/kg. Fullerenol C₆₀(OH)₂₄ was administrated to the treated animals i.p. (in doses 50, 100, 200 mg/kg) 30 min before the dosing with doxorubicin. The control group animals were given saline (1 ml/kg; i.p.). One group of animals was treated only with fullerenol (100 mg/kg i.p.). The animals were sacrificed 2 and 14 days after the treatment. Each experiment was repeated twice. The results may indicate that fullerenol induces a decrease in the antioxidative capacity of erythrocytes in oxidative stress conditions, whereas, without doxorubicin, the application of fullerenol did not induce any changes in the enzyme activity of erythrocytes. The results of GST activity might indicate that 50 mg/kg are not sufficient to protect from doxorubicin toxicity, while 200 mg/kg might be toxic for animals, judging from the increase in GST activity.     

Design,Synthesis, and Antileukemic Activity of Stereochemically Defined Constrained Analogues of FTY720 (Gilenya)

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质子泵抑制剂对大鼠体内氯吡格雷抗血小板作用和代谢的影响

目的 研究各种质子泵抑制剂（proton pump inhibitors,PPIs）对大鼠体内氯吡格雷抗血小板作用和代谢的影响。方法 将40只SD ♂大鼠随机分为氯吡格雷组、氯吡格雷+雷贝拉唑组、氯吡格雷+泮托拉唑组、氯吡格雷+兰索拉唑组和氯吡格雷+奥美拉唑组,每组8只。氯吡格雷、雷贝拉唑、泮托拉唑、兰索拉唑和奥美拉唑的给药剂量分别为6.25,1.8,3.6,2.7,3.6 mg·kg^-1·d^-1,连续给药7 d。分别使用光学比浊法和血管扩张刺激磷酸蛋白检测法检测最大血小板聚集率（maximum platelet aggregation rate,MPA）和血小板反应指数（platelet response index,PRI）,并通过LC-MS/MS检测氯吡格雷及其活性代谢物H4的血药浓度。结果 氯吡格雷+雷贝拉唑组、氯吡格雷+兰索拉唑组和氯吡格雷+奥美拉唑组的MPA和PRI均显著高于氯吡格雷组,氯吡格雷+泮托拉唑组的MPA和PRI显著低于氯吡格雷+奥美拉唑组（P<0.05）。与氯吡格雷组比较,氯吡格雷+雷贝拉唑组、氯吡格雷+兰索拉唑组和氯吡格雷+奥美拉唑组的氯吡格雷血药浓度升高,H4血药浓度降低,但差异无统计学意义。结论 联用雷贝拉唑、兰索拉唑及奥美拉唑均会减弱氯吡格雷的抗血小板作用,其中泮托拉唑的抑制作用最弱,奥美拉唑的抑制作用最强。     

Phase I study of combined alpha Interferon,alpha difluoromethylornithine (DFMO), and doxorubicin in advanced malignancy

Interferon (IFN) and conventional cytotoxic chemotherapeutic agents have been successfully combined in various studies. Alpha difluoromethylornithine (DFMO) is a novel antitumor agent which is an inhibitor of polyamine metabolism. A phase I study of IFN 24 × 10⁶ U/m²/day IM (days 3–7), DFMO 9 gm/m² p.o. daily (days 1–7), and a variable dose of doxorubicin starting at 20 mg/m² (day 6), of each 28 day cycle was performed. The aim of the study was to determine the maximally tolerable dose of doxorubicin in this combination. Three patients were treated with doxorubicin at 20 mg/m² and six patients at 40 mg/m². The dose limiting toxicities were neutropenia, fatigue and fever. All other toxicities were mild and there was no grade IV toxicity. A doxorubicin dose of 40 mg/m² produced tolerable toxicity and is recommended for phase II studies. No major antitumor effects were seen.     

Influence of Vehicle,Distant Topical Delivery,and Biotransformation on the Chemopreventive Activity of Apigenin,a Plant Flavonoid,in Mouse Skin

Purpose. This study was designed to (a) establish a short-term in vivo system to evaluate topical formulations of apigenin, (b) determine whether apigenin should be topically delivered to the local skin tissue or systemic circulation, (c) investigate if biotransformation was involved in apigenin's chemopreventive activity. Methods. The effect of topical applied apigenin in acetone/DMSO (A/D, 9:1) on the promotion of skin tumorigenesis was studied. The influence of apigenin in DMSO, A/D (4:1), and propylene glycol/ DMSO (PG/D, 4:1) on 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ornithine decarboxylase (ODC) activity was compared. Distant topical delivery of apigenin was conducted on abdominal skin and ODC activity was monitored in dorsal skin. Potential glucuronidation/ sulfation of apigenin in intact skin was assessed by measuring isolated apigenin before and after enzyme hydrolysis with glucuronidase/sulfatase. The epidermal extracts from apigenin-treated SENCAR mice were analyzed for metabolites by HPLC. Results. Apigenin (5µmol) in A/D did not significantly reduce skin tumor incidence in contrast to previous data with DMSO. Inhibition of TPA-induced ODC by apigenin in three vehicles was in the order of DMSO > A/D > PG/D. TPA-induced ODC in dorsal skin was not inhibited by apigenin delivered from abdominal skin. The quantity of apigenin recovered from epidermal extract was not different before and after -glucuronidase/sulfatase treatment. Metabolites were not observed in the HPLC profiles of epidermal extracts from apigenin-treated mice. Conclusions. (a) The short-term TPA-induced ODC was validated for evaluating topical formulations of apigenin. (b) Topical delivery of apigenin should target the local skin tissue, (c) Glucuronidation/sulfation appeared not to be involved in apigenin's chemopreventive activity.     

The Role of Flavin-Containing Monooxygenase (FMO) in the Metabolism of Tamoxifen and Other Tertiary Amines

Tamoxifen is utilized in breast cancer therapy and in chemoprevention. Tamoxifen may enhance risk for other neoplasias, especially endometrial cancer. The risk:benefit depends on the rate of metabolic activation versus detoxication. Cytochrome P450-dependent α-hydroxylation, followed by sulfonation, represents a metabolic activation pathway, producing products capable of covalent DNA adduction. In contrast, tamoxifen N-oxygenation represents a detoxication pathway, with the caveat that N-oxides can be reduced back to the parent amines. The N-oxygenation pathway will be the focus for this review. Dr. David Kupfer pioneered studies on cytochrome P450 and flavin-containing monooxygenase (FMO) tamoxifen metabolism. We collaborated with Dr. Kupfer's laboratory and recently determined that the low level of tamoxifen N-oxide production in human liver microsomes may be explained by the kinetics of FMO1 versus FMO3.     

Metabolism of free fatty acids (FA) and triacylglycerol (TG) in acute and subacute fluoride intoxication of the rat

In rats acute intoxication with 100 mg sodium fluoride/kg body wt. orally has the following metabolic consequences. Oxygen consumption is reduced by about 30–50%. Plasma free FA decrease in fed as well as in starved rats. Hepatic FA synthesis is enhanced, but TG secretion to the blood is not altered. Intravenously injected Intralipid^® 20% is removed at a normal rate. In subacute intoxication (30 mg sodium fluoride/kg body wt given orally per day over 1 week) oxygen consumption is not affected. TG secretion and removal of Intralipid remain in the normal range whereas hepatic FA synthesis is increased as in acute intoxication. TG concentration in the liver, however, increases by about 30% after 1 week.Dedicated to Dr. Kurt Binder, deceased 1984This work was supported by Hochschuljubiläumsfonds der Gemeinde Wien und Gebro AG, Fieberbrunn, Austria.