Twenty-eight compounds related to dehydrozingerone (1), isoeugenol (3), and 2-hydroxychalcone (4) were synthesized and evaluated in vitro against human tumor cell replication. Except for isoeugenol analogs 27−35, most compounds exhibited moderate or strong cytotoxic activity against KB, KB-VCR (a multi-drug resistant derivative), and A549 cell lines. In particular, chalcone 15 showed significant cytotoxic activity against the A549 cell line with an IC50 value of 0.6 μg/mL. Furthermore, dehydrozingerone analog 11 and chalcones 16 and 17 showed significant and similar cytotoxic activity against both KB (IC50 values of 2.0, 1.0, and 2.0 μg/mL, respectively) and KB-VCR (IC50 values of 1.9, 1.0, and 2.0 μg/mL, respectively) cells, suggesting that they are not substrates for the p-glycoprotein drug efflux pump.
Dehydrozingerone analogs and related compounds were screened as potential antitumor promoters by using the in vitro short-term 12-O-tetradecanphorbol-13-acetate (TPA)-induced Epstein-Barr virus early antigen (EBV-EA) activation assay. Among 40 synthesized compounds, the prenylated analogs 16 and 34–36 showed the most significant and promising activity (100% inhibition of activation at 1×10 3 mol ratio/TPA, and 82–80%, 37–35%, 13–11% inhibition at 5×102, 1×102, 1×10 mol ratio/TPA, respectively) in this screening. Their activity profiles were comparable to that of the reference standard curcumin. While a prenyl moiety conferred potent chemopreventive activity, an extended prenyl unit such as a farnesyl moiety did not improve activity. Because in vitro inhibitory effects in this assay generally correlate well with in vivo inhibitory effects on tumor promotion, our results strongly suggested that prenylated 16 and 34–36 are likely to be promising antitumor promoters.
dehydrozingerone; antitumor-promoting effect; Epstein-Barr virus; two-stage carcinogenesis
Derivatives of oleanolic acid, ursolic acid and glycyrrhetinic acid substituted with electron withdrawing groups at the 2-position in the A-ring which also contains a 1-en-3-one structure are potent inhibitors of cancer cell growth. In this study, we have compared the effects of several 2-substituted analogs of triterpenoid acid methyl esters derived from ursolic and glycyrrhetinic acid on proliferation of KU7 and 253JB-V bladder and Panc-1 and Panc-28 pancreatic cancer cells. The results show that the 2-cyano and 2-trifluoromethyl derivatives were the most active compounds. The glycyrrhetinic acid derivatives with the rearranged C-ring containing the 9(11)-en-12-one structure were generally more active than the corresponding 12-en-11-one isomers. However, differences in growth inhibitory IC50 values were highly variable and dependent on the 2- substitutent (CN vs. CF3) and cancer cell context.
glycyrrhetinate analogs; growth inhibition; bladder cancer; pancreatic cancer
Fifteen different taxoid conjugates were prepared by linking various anticancer compounds, including camptothecin (CPT), epipodophyllotoxin (EP), colchicine (COL), and glycyrrhetinic acid (GA), at the 2’- or 7-position on paclitaxel (TXL, 1) through an ester, imine, amine, or amide bond. Newly synthesized conjugates were evaluated for cytotoxic activity against replication of several human tumor cell lines. Among them, TXL-CPT conjugates, 8–10, were more potent than TXL itself against the human prostate carcinoma cell line PC-3 (ED50 = 14.8, 3.1, 19.4 nM compared with 55.5 nM), and conjugate 10 was also eightfold more active than TXL against the LN-CAP prostate cancer cell line. These compounds also possessed anti-angiogenesis ability as well as lower inhibitory effects against a normal cell line (MRC-5). Thus, conjugates 8–10 are possible antitumor drug candidates, particularly for prostate cancer.
Paclitaxel; Conjugation; Cytotoxity; Prostate cancer
This study discovered that glycyrrhetinic acid inhibited the human 20S proteasome at 22.3 µM. Esterification of the C-3 hydroxyl group on glycyrrhetinic acid with various carboxylic acid reagents yielded a series of analogs with marked improved potency. Among the derivatives, glycyrrhetinic acid 3-O-isophthalate (17) was the most potent compound with IC50 of 0.22 µM, which was approximately 100-fold more potent than glycyrrhetinic acid.
Glycyrrhetinic acid; proteasome inhibitor; triterpene
Synthetic analogues of naturally occurring triterpenoids; glycyrrhetinic acid, arjunolic acid and boswellic acids, by modification of A-ring with a cyano- and enone- functionalities, have been reported. A novel method of synthesis of α-cyanoenones from isoxazoles is reported. Bio-assays using primary mouse macrophages and tumor cell lines indicate potent anti-inflammatory and cytotoxic activities associated with cyanoenones of boswellic acid and glycyrrhetinic acid.
Previous reports from our laboratory have shown that a bifunctional agent obtained by conjugating a photosensitizer (HPPH) to a cyanine dye (CD) can be used for fluorescence image-guided treatment of tumor by photodynamic therapy (PDT). However, the resulting HPPH-CD conjugate showed a significant difference between the tumor-imaging and therapeutic doses. It was demonstrated that the singlet oxygen (1O2*, a key cytotoxic agent in PDT) produced by the conjugate upon excitation of the HPPH moiety was partially quenched by the CD-moiety; this resulted in a reduced PDT response when compared to HPPH-PDT under similar treatment parameters. To improve the therapeutic potential of the conjugate, we synthesized a series of dual functional agents in which one or two HPPH moieties were separately conjugated to three different dyes (Cypate, modified IR820 or modified IR783). The newly synthesized conjugates were compared with our lead compound HPPH-CD in terms of photophysical properties, in vitro and in vivo PDT efficacy, tumor uptake and imaging potential. Among the analogs investigated, the conjugate, in which two HPPH moieties were linked to the modified IR820 produced enhanced tumor uptake and tumor contrast in both Colon 26 (a murine Colon carcinoma) and U87 (a human glioblastoma) cell lines. The long-term PDT efficacy (cure) of this conjugate in BALB/c mice, bearing Colon 26 tumors was also enhanced; however, its efficacy in Nude mice bearing U87 tumors was slightly reduced. It was also found that in all the conjugates the singlet oxygen generation and, consequently, PDT efficacy were compromised by a competing pathway, whereby an electronic excitation of HPPH, the energy donor, is deactivated through an electronic excitation energy transfer (Forster Resonance Energy Transfer, FRET) to the CD fluorophore, the energy acceptor, resulting in overall reduction of the singlet oxygen production. Conjugates with increased FRET showed reduced singlet oxygen production and PDT efficacy. Among the conjugates investigated, the bifunctional agent in which two HPPH moieties were linked to the benzoindole-based cyanine dye 11 showed superiority over the lead candidate 9 (mono HPPH-cyanine dye).
Photodynamic therapy, Fluorophores, Reactive Oxygen species; Imaging. Forster Resonance Energy Transfer.
Triterpenoids are used for medicinal purposes in many countries. Some, such as oleanolic and glycyrrhetinic acids, are known to be anti-inflammatory and anticarcinogenic. However, the biological activities of these naturally occurring molecules against their particular targets are weak, so the synthesis of new synthetic analogues with enhanced potency is needed. By combining modifications to both the A and C rings of 18βH-glycyrrhetinic acid, the novel synthetic derivative methyl 2-cyano-3,12-dioxo-18βH-olean-9(11),1(2)-dien-30-oate was obtained. This derivative displays high antiproliferative activity in cancer cells, including a cell line with a multidrug-resistance phenotype. It causes cell death by inducing the intrinsic caspase-dependent apoptotic pathway.
antitumor agents; apoptosis; biological activity; glycyrrhetinic acid derivatives; medicinal chemistry
The title compound, C33H49NO3, is the propargylamide of 18β-glycyrrhetinic acid, a pentacyclic triterpenoid of interest as a therapeutic agent. The five six-membered rings of the glycyrrhetinic acid moiety show normal geometries, with four rings in chair conformations and the unsaturated ring C in a half-chair conformation. In the crystal, the terminal N-propargylcarboxamide group has remarkable structural effects on weak hydrogen-bond-like interactions. Particularly noteworthy are an intermolecular O—H⋯π interaction accepted side-on by the terminal alkyne group [O⋯C = 3.097 (2) and 3.356 (2) Å] and a short intermolecular C—H⋯O interaction [C⋯O = 3.115 (2) Å] donated by the alkyne C—H group. An N—H⋯O [N⋯O = 3.251 (2) Å] and a Calkyl—H⋯O [C⋯O = 3.254 (2) Å] interaction complement the crystal structure.
Malaria is one of the most prevailing fatal diseases causing between 1.2 and 2.7 million deaths all over the world each year. Further, development of resistance against the frontline anti-malarial drugs has created an alarming situation, which requires intensive drug discovery to develop new, more effective, affordable and accessible anti-malarial agents possessing novel modes of action. Over the past few years triterpenoids from higher plants have shown a wide range of anti-malarial activities. As a part of our drug discovery program for anti-malarial agents from Indian medicinal plants, roots of Glycyrrhizaglabra were chemically investigated, which resulted in the isolation and characterization of 18β-glycyrrhetinic acid (GA) as a major constituent. The in vitro studies against P. falciparum showed significant (IC50 1.69µg/ml) anti-malarial potential for GA. Similarly, the molecular docking studies showed adequate docking (LibDock) score of 71.18 for GA and 131.15 for standard anti-malarial drug chloroquine. Further, in silico pharmacokinetic and drug-likeness studies showed that GA possesses drug-like properties. Finally, in vivo evaluation showed a dose dependent anti-malarial activity ranging from 68–100% at doses of 62.5–250mg/kg on day 8. To the best of our knowledge this is the first ever report on the anti-malarial potential of GA. Further work on optimization of the anti-malarial lead is under progress.
A targeted dendrimeric anticancer prodrug, a conjugate of Generation 5 (G5) polyamidoamine (PAMAM) dendrimer, folic acid (FA), and methotrexate (MTX), has been successfully synthesized by using a novel “one pot” approach which is simple, reproducible and feasible for large-scale synthesis. All dendrimer products have been characterized by 1H NMR, MALDI-TOF, GPC, and HPLC. With this new method, the ratio of FA versus MTX attached to the dendrimer can be easily tuned to achieve the desired therapeutic effect. A new analytical approach for calculating the numbers of FA and MTX attached to the dendrimer has been established. In vitro studies performed on FA receptor-expressing KB cells show that the new conjugate has a similar affinity and cytotoxic potency to G5-FA-MTX synthesized using the traditional multiple-step approach.
Anticancer drugs are often nonselective antiproliferative agents (cytotoxins) that preferentially kill dividing cells by attacking their DNA at some level. The lack of selectivity results in significant toxicity to noncancerous proliferating cells. These toxicities along with drug resistance exhibited by the solid tumors are major therapy limiting factors that results into poor prognosis for patients. Prodrug and conjugate design involves the synthesis of inactive drug derivatives that are converted to an active form inside the body and preferably at the site of action. Classical prodrug and conjugate design has focused on the development of prodrugs that can overcome physicochemical (e.g., solubility, chemical instability) or biopharmaceutical problems (e.g., bioavailability, toxicity) associated with common anticancer drugs. The recent targeted prodrug and conjugate design, on the other hand, hinges on the selective delivery of anticancer agents to tumor tissues thereby avoiding their cytotoxic effects on noncancerous cells. Targeting strategies have attempted to take advantage of low extracellular pH, elevated enzymes in tumor tissues, the hypoxic environment inside the tumor core, and tumor-specific antigens expressed on tumor cell surfaces. The present review highlights recent trends in prodrug and conjugate rationale and design for cancer treatment. The various approaches that are currently being explored are critically analyzed and a comparative account of the advantages and disadvantages associated with each approach is presented.
Prodrugs; conjugates; targeted design; nanotechnology; anticancer
The aim of this study is to test the hypothesis that the newly synthesized poly(δ-valerolactone)/poly(ethylene glycol)/poly(δ-valerolactone) (VEV) copolymer grafted with folic acid would impart targetability and further enhance the anti-tumor efficacy of doxorubicin (DOX). Here, folic acid conjugated VEV (VEV-FOL) was synthesized by a modified esterification method and characterized using IR and NMR. DOX loaded VEV-FOL micelles were synthesized using a novel solvent evaporation method and were obtained with a mean diameter of 97 nm with high encapsulation efficiency and sustained in vitro release profile. Comparative studies of polymer micelles with and without folate for cellular uptake and cytotoxicity were done on folate receptor-positive breast cancer cell line, MDAMB231. The intracellular uptake tests showed significant increase in folate micellar uptake when compared to non-folate-mediated micelles. MTT assay followed by apoptosis assays clearly indicated that folate decorated micelles showed significantly better cytotoxicity (IC50 = 0.014 µM) and efficiency to induce apoptosis than other treated groups. Moreover, a significant G2/M arrest was induced by DOX loaded VEV-FOL micelles at a concentration where free drug failed to show any activity. Thus, our results show that the folic acid-labeled VEV copolymer is a promising biomaterial with controlled and sustainable tumor targeting ability for anticancer drugs which can open new frontiers in the area of targeted chemotherapy.
Elastin-like polypeptide (ELP) is a macromolecular carrier with thermally responsive properties that can passively accumulate in solid tumors and additionally aggregate in tumor tissue when exposed to hyperthermia. In this study, ELP was conjugated to the anticancer drug doxorubicin (DOXO) and three different cell-penetrating peptides (CPP) in order to inhibit tumor growth in mice compared to free doxorubicin. Fluorescence microscopy studies in MCF-7 breast carcinoma cells demonstrated that the three different CPP-ELP-DOXO conjugates delivered doxorubicin to the cell nucleus. All CPP-ELP-DOXO conjugates showed cytotoxicity with IC50 values in the range of 12-30 μM at 42 °C, but the ELP carrier with SynB1 as the cell-penetrating peptide had the lowest intrinsic cytotoxicity. Therefore, the antitumor efficacy of SynB1-ELP-DOXO was compared to doxorubicin under hyperthermic conditions. C57BL/6 female mice bearing syngeneic E0771 murine breast tumors were treated with either free doxorubicin or the SynB1-ELP-DOXO conjugate with or without focused hyperthermia on the tumor. Under hyperthermic conditions, tumor inhibition with SynB1-ELP-DOXO was 2-fold higher than under therapy with free doxorubicin at the equivalent dose, and is thus a promising lead candidate for optimizing thermally responsive drug polymer conjugates.
ELP – elastin-like polypeptide; doxorubicin; (6-maleimidocaproyl)hydrazone derivative of doxorubicin (DOXO-EMCH, INNO-206); acid-sensitive prodrugs; CPP - cell penetrating peptide; hyperthermia
To develop novel bifunctional agents for tumor imaging (MR) and photodynamic therapy (PDT) certain tumor-avid photosensitizers derived from chlorophyll-a were conjugated with variable number of Gd(III)aminobenzyl DTPA moieties. All the conjugates containing three or six gadolinium units showed significant T1 and T2 relaxivities. However, as a bifunctional agent, the 3-(1′-hexyloxyethyl)pyropheophorbide-a (HPPH) containing 3Gd(III) aminophenyl DTPA was most promising with possible applications in tumor-imaging and PDT. Compared to HPPH, the corresponding 3- and 6Gd(III)aminobenzyl DTPA conjugates exhibited similar electronic absorption characteristics with a slightly decreased intensity of the absorption band at 660 nm. However, compared to HPPH, the excitation of the broad “Soret” band (near 400 nm) of the corresponding 3Gd(III)aminobenzyl-DTPA analogs showed a significant decrease in the fluorescence intensity at 667 nm, which was further diminished by increasing the number of Gd(III)units.
Thymidine kinases (TKs) have been considered one of the potential targets for anticancer therapeutic because of their elevated expressions in cancer cells. However, nucleobase analogs targeting TKs have shown poor selective cytotoxicity in cancer cells despite effective antiviral activity. 3′-Deoxythymidine phenylquinoxaline conjugate (dT-QX) was designed as a novel nucleobase analog to target TKs in cancer cells and block cell replication via conjugated DNA intercalating quinoxaline moiety. In vitro cell screening showed that dT-QX selectively kills a variety of cancer cells including liver carcinoma, breast adenocarcinoma and brain glioma cells; whereas it had a low cytotoxicity in normal cells such as normal human liver cells. The anticancer activity of dT-QX was attributed to its selective inhibition of DNA synthesis resulting in extensive mitochondrial superoxide stress in cancer cells. We demonstrate that covalent linkage with 3′-deoxythymidine uniquely directed cytotoxic phenylquinoxaline moiety more toward cancer cells than normal cells. Preliminary mouse study with subcutaneous liver tumor model showed that dT-QX effectively inhibited the growth of tumors. dT-QX is the first molecule of its kind with highly amendable constituents that exhibits this selective cytotoxicity in cancer cells.
Breast cancer remains a major cause of death in the United States as well as the rest of the world. In view of the limited treatment options for patients with advanced breast cancer, preventive and novel therapeutic approaches play an important role in combating this disease. The plant-derived triterpenoids, commonly used for medicinal purposes in many Asian countries, posses various pharmacological properties. A large number of triterpenoids are known to exhibit cytotoxicity against a variety of tumor cells as well as anticancer efficacy in preclinical animal models. Numerous triterpenoids have been synthesized by structural modification of natural compounds. Some of these analogs are considered to be the most potent antiinflammatory and anticarcinogenic triterpenoids known. This review examines the potential role of natural triterpenoids and their derivatives in the chemoprevention and treatment of mammary tumors. Both in vitro and in vivo effects of these agents and related molecular mechanisms are presented. Potential challenges and future directions involved in the advancement of these promising compounds in the prevention and therapy of human breast cancer are also identified.
Apoptosis; Breast Cancer; Chemoprevention; Review; Treatment; Triterpenoids; Tumor Cells
We report the synthesis of novel acid-responsive therapeutic nanoparticles (NPs) with sub-100 nm size consisting of polymer-cisplatin conjugates. The uniqueness of these drug delivery polymeric NPs lies in the covalent conjugation of each cisplatin drug to the hydrophobic segment of two biocompatible diblock copolymer chains through hydrazone bond, resulting in highly differential drug release profile at different environmental acidity. We demonstrate that the synthesized polymer-cisplatin conjugates can readily precipitate to form sub-100 nm NPs in aqueous solution due to their very low critical micellar concentration (CMC). The resulting NPs show well controlled cisplatin loading yield, excellent acid-responsive drug release kinetics, and enhanced in vitro cytotoxicity against ovarian cancer cells as compared to free cisplatin. As an environmentally sensitive drug delivery vehicle, these NPs can potentially minimize the drug loss during NP circulation in the blood where the pH value is neutral and trigger rapid intracellular drug release after the NPs are endocytosed by the target cells. This characteristic drug release profile holds the promise to suppress cancer cell chemoresistance by rapidly releasing a high dose of chemotherapy drugs inside the tumor cells, thereby improving the therapeutic efficacy of the drug payload.
Polymeric nanoparticle; Cisplatin; Drug delivery; Controlled release; Stimuli-responsive
Conjugates of methotrexate (MTX) and the nucleoside analogs 3-azidodeoxythymidine (AZT), iododeoxyuridine (IUdR) and dideoxycytidine (ddC) linked using poly(ethyleneglycol) are presented. In vitro cytotoxicity assays of the conjugates against drug resistant ovarian cell line A2780/AD are preformed and comparisons made to such assays performed for unconjugated (cocktail) systems. All systems tested were inactive, or had low activity, at 24 h. After 72 hr incubation however, the cocktails of MTX and AZT, IUdR or ddC showed high cytotoxicity in the low nanomolar range. The conjugates were only very moderately active with IC50 values in the [0.1 to 1.0 mM] range. Conjugation of the antifolate to the nucleoside analogs has it seems reduced the activity significantly when compared to a cocktail of the components, indicating a conjugate approach is unlikely to translate into success in vivo. The positive note comes from the observation that by combining two of the new conjugates, namely those based on MTX with IUdR or AZT, an IC50 at 24 hours of ~ [180 μM] was produced.
nucleosides; folic acid; cocktail therapy; conjugates; PEG
Stimulus-sensitive micelles are attractive anticancer drug delivery systems. Herein we reported a novel strategy to engineer acid-sensitive micelles using a amphiphilic material synthesized by directly conjugating the hydrophilic polyethylene glycol (PEG) with a hydrophobic stearic acid derivative (C18) using an acid-sensitive hydrazone bond (PHC). An acid-insensitive PEG-amide-C18 (PAC) compound was also synthesized as a control. 4-(N)-stearoyl gemcitabine (GemC18), a prodrug of the nucleoside analog gemcitabine, was loaded into the micelles, and they were found to be significantly more cytotoxic to tumor cells than GemC18 solution, likely due to the lysosomal delivery of GemC18 by micelles. Moreover, GemC18 in the acid-sensitive PHC micelles was more cytotoxic than in the acid-insensitive PAC micelles, which may be attributed to the acid-sensitive release of GemC18 from the PHC micelles in lysosomes. In B16-F10 melanoma-bearing mice, GemC18-loaded PHC or PAC micelles showed a stronger antitumor activity than GemC18 or gemcitabine solution, likely because of the prolonged circulation time and increased tumor accumulation of the GemC18 by the micelles. Importantly, the in vivo antitumor activity of GemC18-loaded PHC micelles was significantly stronger than that of the PAC micelles, demonstrating the potential of the novel acid-sensitive micelles as an anticancer drug delivery system.
This work is intended to develop and evaluate a biopolymeric poly(L-γ-glutamylglutamine) (PGG)–docetaxel (DTX) conjugate that can spontaneously self-assemble in aqueous solutions to become nanoparticles.
DTX was covalently attached to hydrophilic PGG by direct esterification, and the conjugate was characterized by proton nuclear magnetic resonance spectroscopy, molecular weight gel permeation chromatography, solubility, size distribution and morphology, and hemolysis. Conjugated DTX was found to have 2000 times improved water solubility compared with free DTX. Dynamic light scattering, transmission electron microscopy, and atomic force microscopy revealed the particle size, distribution and morphology of the PGG–DTX conjugate. In addition, the conjugate was further tested for in vitro cytotoxicity and in vivo antitumor efficacy on the human non-small cell lung cancer cell line NCI-H460.
Conjugated DTX was found to have 2000 times improved water solubility compared with free DTX. The conjugate formed nanoparticles with an average diameter of 30 nm in spherical shape and unimodal particle size distribution. The conjugate exhibited about 2% hemolysis at 10 mg/mL, compared with 56% for Tween 80® at 0.4 mg/mL, and 33% for Cremophor EL® at 10 mg/mL. In addition, the conjugate was further tested for in vitro cytotoxicity and in vivo antitumor efficacy on the human non-small cell lung cancer cell line NCI-H460. As expected, conjugated DTX exhibited lower cytotoxicity compared to that of free DTX, in concentration-dependent manner. However, PGG–DTX showed better antitumor activity in NCI-H460 lung cancer-bearing mice with minimal weight loss compared to that of free DTX.
The PGG–DTX conjugate may be considered as an attractive and promising polymeric DTX conjugate for non-small cell lung cancer treatment.
polymer drug delivery; nanotechnology; nanotherapeutics; drug delivery; nanomedicine; pharmaceutics
Active components of complementary/alternative medicines and natural supplements are often anionic compounds and flavonoids. As such, organic anion transporters (OATs) may play a key role in their pharmacokinetic and pharmacological profiles, and represent sites for adverse drug-drug interactions. Therefore, we assessed the inhibitory effects of nine natural products, including flavonoids (catechin and epicatechin), chlorogenic acids (1,3- and 1,5-dicaffeoylquinic acid), phenolic acids (ginkgolic acids (13 : 0), (15 : 1), and (17 : 1)), and the organic acids ursolic acid and 18β-glycyrrhetinic acid, on the transport activity of the human OATs, hOAT1 (SLC22A6), hOAT3 (SLC22A8), and hOAT4 (SLC22A11). Four compounds, 1,3- and 1,5-dicaffeoylquinic acid, ginkgolic acid (17 : 1), and 18β-glycyrrhetinic acid, significantly inhibited hOAT1-mediated transport (50 μM inhibitor versus 1 μM substrate). Five compounds, 1,3- and 1,5-dicaffeoylquinic acid, ginkgolic acids (15 : 1) and (17 : 1), and epicatechin, significantly inhibited hOAT3 transport under similar conditions. Only catechin inhibited hOAT4. Dose-dependency studies were conducted for 1,3-dicaffeoylquinic acid and 18β-glycyrrhetinic acid on hOAT1, and IC50 values were estimated as 1.2 ± 0.4 μM and 2.7 ± 0.2 μM, respectively. These data suggest that 1,3-dicaffeoylquinic acid and 18β-glycyrrhetinic acid may cause significant hOAT1-mediated DDIs in vivo; potential should be considered for safety issues during use and in future drug development.
Our earlier studies have shown the in vitro and in vivo targeting of a generation 5 (G5) dendrimer-based multifunctional conjugate that contained folic acid (FA) as the targeting agent and methotrexate (MTX) as the chemotherapeutic drug. To clinically apply the synthesized G5-FA-MTX nanotherapeutic, it is important that the anticancer conjugate elicits cytotoxicity specifically and consistently. Toward this objective, we evaluated the large-scale synthesis of a G5-FA-MTX conjugate (Lot # 123–34) for its cytotoxic potential and specificity in vitro and in vivo. The cytotoxicity and specificity were tested by using a coculture assay in which FA receptor-expressing and nonexpressing cells (KB and SK-BR-3 cells, respectively) were cultured together and preferential killing was examined. The in-vitro data were compared with the in-vivo data obtained from a heterogeneous xenograft tumor model. The animal model of the artificial heterogeneous xenograft tumor showed that the nanotherapeutic was preferentially cytotoxic to KB cells.
coculture assay; dendrimer; heterogeneous xenograft tumor model; methotrexate; neoplasm; targeted drug delivery
Ibuprofen–polyethylene glycol (PEG) conjugates (PEG-Ibu) were prepared and their potential as a prolonged release system was investigated. Two PEG-Ibu conjugates were synthesized from Ibuprofen and PEG with two different molecular weights by esterification in the presence of DCC and DMAP. The PEG-Ibu conjugates were characterized by FT-IR, 1H NMR, Mass spectroscopy and DSC analysis. The solubility study in aqueous system showed an increase in solubility of conjugates. The dissolution / hydrolysis studies showed a specific acid–base catalysis pattern dependent on the pH of the medium. This indicated a good chemical stability in aqueous buffer solution of acidic medium and the extended release behavior was found in both prodrugs after 9 hour. The results demonstrate that, in the same condition, the rate of hydrolysis for PEG4000-Ibu is slower than other. The Writhing induced by acetic acid experiment and paw edema test after oral administration showed that both conjugates had extended analgesic and anti-inflammatory effects compared with Ibuprofen. These results suggest that PEG-Ibu could be a promising NSAID prodrug with an extended pharmacological effect owing to delayed-release of parent drug.
Ibuprofen; Poly(ethylene glycol); Conjugation; Analgesic; Anti-inflammatory
Ganoderma fungus (Ganodermataceae) is a multifunctional medicinal mushroom and has been traditionally used for the treatment of various types of disease. Ganoderic acid DM (1) is a representative triterpenoid isolated from G. lingzhi and exhibits various biological activities. However, a universal starting point that triggers multiple signaling pathways and results in multifunctionality of 1 is unknown. Here we demonstrate the important clues regarding the mechanisms underlying multi-medicinal action of 1. We examined structure–activity relationships between 1 and its analogs and found that the carbonyl group at C-3 was essential for cytotoxicity. Subsequently, we used 1-conjugated magnetic beads as a probe and identified tubulin as a specific 1-binding protein. Furthermore, 1 showed a similar Kd to that of vinblastine and also affected assembly of tubulin polymers. This study revealed multiple biological activities of 1 and may contribute to the design and development of new tubulin-inhibiting agents.