Antitumour activity of Terminalia arjuna leaf against Ehrlich ascites carcinoma in mice

Terminalia arjuna Roxb. (Combretaceae), commonly known as 'Arjuna', is a large tree occurring throughout the Indian peninsula. This study was undertaken to evaluate the methanol extract of T. arjuna leaf (META) for antitumour activity against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. Twenty-four hours after intraperitonial inoculation of tumour (EAC) cells in mice, META was administered at 100 and 200?mg?kg(-1) body weights for 9 consecutive days. On day 10, half of the mice were sacrificed and the rest kept alive for an assessment of the increase in life span. The antitumour effect of META was assessed by evaluating tumour volume, tumour weight, viable and non-viable tumour cell counts, median survival time and increase in life span of EAC-bearing hosts. Haematological profiles were estimated. META showed a significant (p<0.001) decrease in tumour volume, tumour weight and viable cell count, and also increased the life span of EAC-bearing mice. Haematological profiles were significantly (p<0.001) restored to normal levels in META-treated mice compared to the EAC control. Therefore, from this study, it can be concluded that T. arjuna leaf exhibited remarkable antitumour activity against EAC in Swiss mice.     

Doxorubicin Encapsulated in TPGS-Modified 2D-Nanodisks Overcomes Multidrug Resistance

Multidrug resistance (MDR) is regarded as a main obstacle for effective chemotherapy, and P-glycoprotein (P-gp)-mediated drug efflux has been demonstrated to be the key factor responsible for MDR. In this study, a novel pH-responsive hybrid drug delivery system was developed by conjugating d -α-tocopheryl polyethylene glycol 1000 succinate (TPGS), a kind of P-gp inhibitor, on the surface of laponite nanodisks to overcome MDR. The prepared LM-TPGS display excellent colloidal stability, a high encapsulation efficiency of doxorubicin (DOX), and a pH-responsive drug release profile. In vitro experiments verified that LM-TPGS/DOX could exhibit significantly enhanced therapeutic efficacy in treating DOX-resistant breast cancer cells (MCF-7/ADR) through inhibiting the activity of P-gp-mediated drug efflux and effectively accumulating DOX within cancer cells. In vivo results revealed that LM-TPGS/DOX outstandingly suppressed MCF-7/ADR tumors with low side effects. Therefore, the high drug payload, enhanced inhibition efficacy to drug-resistant cells, and low side effects make the LM-TPGS/DOX a promising nanoplatform to reverse MDR for effective chemotherapy.     

Isolation of a new triterpene derivative and in vitro and in vivo anticancer activity of ethanolic extract from root bark of Zizyphus nummularia Aubrev

The various parts of Zizyphus nummularia has been used traditionally in several disease conditions. However, its anticancer activity and mechanism of action remain to be elucidated. Considering this, the objective of this study was to isolate, identify and screen for possible anticancer activity in vitro and in vivo of the ethanolic extract (EE) and isolated identified compound (IC) from Z. nummularia root bark. The in vitro activity against human breast cancer, leukaemia, ovarian cancer, colon adenocarcinoma and human kidney carcinoma cell lines was determined. The in vivo activity in female Swiss albino mice against Ehrlich ascites carcinoma (EAC) was determined. The isolated compound is a new triterpene derivative. EE/IC showed cytotoxicity against different cell lines. The administration of EE/IC decreased tumour parameters such as tumour volume, viable tumour cell count and increased body weight, haematological parameters and life span in comparison to the EAC control mice.     

Antitumour activity of Prosopis cineraria (L.) Druce against Ehrlich ascites carcinoma-induced mice

The antitumour activity of the hydroalcoholic extract of the leaf (PCL) and stem bark (PCB) of Prosopis cineraria (L.) in Swiss albino mice was evaluated against an Ehrlich ascites carcinoma (EAC) tumour model. The activity was assessed using survival time, peritoneal cells, haematological studies, lipid peroxidation, antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, solid tumour mass and in?vitro cytotoxicity. PCL and PCB were found to be potent and possessed significant cytotoxicity towards EAC tumour cells.     

Antitumour effect of Diospyros cordifolia bark on Ehrlich ascites carcinoma-bearing Swiss albino mice

Diospyros cordifolia Roxb. (Ebenaceae), commonly known as Indian ebony, is used traditionally for several medicinal purposes. In this study, the methanol extract of D. cordifolia bark (MEDC) was evaluated for its antitumour effect against Ehrlich ascites carcinoma (EAC)-bearing Swiss albino mice. Twenty-four hours after intraperitoneal inoculation of tumour (EAC) cells in mice, MEDC was administered intraperitoneally at 25 and 50?mg kg?1 bodyweight for 9 consecutive days. On the 10th day, half of the mice were sacrificed to determine the tumour volume, viable and non-viable tumour cell counts, and rest were kept alive for the assessment of median survival time and increase in life span. Haematological profiles were also determined. MEDC exhibited a marked decrease in tumour growth parameters and increased the survival rate of EAC-bearing animals. MEDC normalised the haematological parameters as compared with the EAC control mice. Therefore, this study demonstrated that D. cordifolia bark possessed remarkable antitumour efficacy.     

Reversal of Multidrug Resistance by Apolipoprotein A1-Modified Doxorubicin Liposome for Breast Cancer Treatment

Multidrug resistance (MDR) remains a major problem in cancer therapy and is characterized by the overexpression of p-glycoprotein (P-gp) efflux pump, upregulation of anti-apoptotic proteins or downregulation of pro-apoptotic proteins. In this study, an Apolipoprotein A1 (ApoA1)-modified cationic liposome containing a synthetic cationic lipid and cholesterol was developed for the delivery of a small-molecule chemotherapeutic drug, doxorubicin (Dox) to treat MDR tumor. The liposome-modified by ApoA1 was found to promote drug uptake and elicit better therapeutic effects than free Dox and liposome in MCF-7/ADR cells. Further, loading Dox into the present ApoA1-liposome systems enabled a burst release at the tumor location, resulting in enhanced anti-tumor effects and reduced off-target effects. More importantly, ApoA1-lip/Dox caused fewer adverse effects on cardiac function and other organs in 4T1 subcutaneous xenograft models. These features indicate that the designed liposomes represent a promising strategy for the reversal of MDR in cancer treatment.     

Reversal effects of traditional Chinese herbs on multidrug resistance in cancer cells

Multidrug resistance (MDR) continues to be a major obstacle for successful anticancer therapy. In this work, fractions from 17 clinically used antitumour traditional Chinese medicinal herbs were tested for their potential to restore the sensitivity of MCF-7/ADR and A549/Taxol cells to a known antineoplastic agent. The effects of these fractions were evaluated by MTT method and an assay of the cellular accumulation of doxorubicin. Fractions from the PB group (herbs with the ability to promote blood circulation and remove blood stasis) showed more significant effects than fractions from the CH group (herbs with the ability to clear away heat and toxic materials). Fractions from CH?Cl? extracts were more effective than fractions from EtOAc extracts. Five herbs (Curcuma wenyujin, Chrysanthemum indicum, Salvia chinensis, Ligusticum chuanxiong Hort. and Cassia tora L.) could sensitise these resistant cancer cells at a non-toxic concentration (10?μg?mL?1), and markedly increased doxorubicin accumulation in MCF-7/ADR cells, which necessitates further investigations on the active ingredients of these herbs and their underlying mechanisms.     

IMPAIRED ACCUMULATION OF A CATIONIC PHOTOSENSITIZING AGENT BY A CELL LINE EXHIBITING MULTIDRUG RESISTANCE

Abstract —Transport and accumulation of copper benzochlorin iminium salt (CDSl), a cationic photosensitizing agent, were examined using the P388/ADR murine leukemia, which exhibits the MDR (multidrug resistance) phe-notype, and the wild-type parent cell line, P388. The recent availability of radioactive CDSl permitted kinetic studies at drug levels in the submicromolar range. Exclusion of CDSl by P38WADR cells could be demonstrated, indicating that this agent is a substrate for the outward transport system associated with MDR. These results have implications with regard to the efficacy of cationic photosensitizers against this common neoplastic phenotype. The CDSl was readily accumulated by P388 cells and by P388/ADR cells: when the outward transport system was inhibited. Under these conditions, CDSl was tightly bound and could not be washed out even when the outward transport system was reactivated.     

Inhibitory potential of Hydroxychavicol on Ehrlich ascites carcinoma model and in silico interaction on cancer targets

Abstract

Hydroxychavicol (HC), a major phenolic derivative isolated from the leaves of Piper betle L. is well known for its antibacterial, antifungal and antimutagenic properties. The present study evaluated the in vivo antitumor activity of HC against Ehrlich Ascites Carcinoma (EAC) cells in Swiss albino mice and in silico interaction of HC with the receptors involved in the cancer. Hydroxychavicol (200 and 400?mg/kg bw) was orally administered for 21 consecutive days and was effective in inhibiting the tumor growth in ascitic mouse model. HC consistently reduced the tumor volume, viable cell count, lipid peroxidation and elevated the life span of HC treated mice. Besides the hematological profiles, SGOT and SGPT levels reverted back to normal and oxidative stress markers GSH, SOD and CAT also increased in HC treated groups. In silico docking analysis revealed that HC possessed potent antagonist activity against all the cancer targets demonstrating its inhibitory activity.     

In vivo anticancer and histopathology studies of Schiff bases on Ehrlich ascitic carcinoma cells: 1st Cancer Update

Three Schiff bases in two different concentrations were evaluated for their anti-tumor activity against Ehrlich ascites carcinoma (EAC) bearing Swiss albino mice. The in vivo anti-tumor potency of Schiff bases was assessed by measuring the increase in mean survival time of the drug treated over untreated control mice and treated standard (cisplatin) mice. Their toxicity was assessed in vivo in normal, standard, and EAC-bearing mice by measuring the drug-induced changes in biochemical as well as hematological parameters. The histopathology studies to assess the toxicity of these compounds on vital organs also have been studied. Among the three Schiff bases studied, 4-({[3-(4-fluorophenyl)-1H-pyrazol-4-yl]methylene}amino)-5-[(2-methylphenoxy)methyl]-1,2,4-triazole-3-thiol (SB-3) at an optimal dose of 100 mg/kg body weight was found to enhance the mean survival time of infected mice. Deviated hematological parameters and mean survival time in tumor bearing mice were found to be significantly restored towards normal after treatment with SB-3 100 mg/kg body weight of mice. The ALP and SGOT values were found to approach the normal range. A:G ratios also did not deviate from normal on treatment with SB-3. The histopathology studies revealed only mild hepatotoxicity and nephrotoxicity when compared to the normal and standard. The splenic cellularity also did not show much variation from normal. SB-3 at a prime dose of 100 mg has shown promising anticancer activity in vivo against EAC when compared to standard drug with minimum toxic effects.     

PORPHYRIN PHOTOSENSITIZATION OF MULTI-DRUG RESISTANT CELL TYPES

The P388 murine leukemia and P388/ADR, a subline expressing the multi-drug resistance (MDR) phenotype, were examined with regard to the role of MDR as a determinant of responsiveness to photodynamic therapy in vitro. Mesoporphyrin was used as a model substrate. We found no differences in porphyrin accumulation nor transport alterations associated with exposure of P388/ADR cells to the verapamil analog DMDP. There was a significant correlation between photodamage to mitochondria vs loss of cell viability in both cell lines, and LD50 sensitizer levels were not significantly different in P388 vs P388/ADR. P388/ADR cells were partly resistant to porphyrin-catalyzed photodamage to amino acid transport, but this result was not associated with differences in sensitizer localization, as indicated by fluorescence studies. Moreover, photodamage to membrane transport was not associated with loss of viability. These studies suggest that cells which express the MDR phenotype are unlikely to be cross-resistant to photodynamic therapy.     

Synthesis,spectroscopic characterization,antineoplastic, in vitro-cytotoxic,and antibacterial activities of mononuclear ruthenium(II) complexes

The synthesis, antineoplastic, cytotoxic, and antibacterial activities of Ru(II) complexes derived from quinazoline and thiosemicarbazone ligands are reported. These complexes have been prepared and characterized by UV-Vis, IR, ¹H-NMR, FAB-mass spectroscopy, and elemental analysis. The ligands and resulting complexes were subjected to in vivo antineoplastic activity against a transplantable murine tumor cell line Ehrlich ascites carcinoma (EAC) and in vitro cytotoxic activity against human cancer cell line Molt 4/C₈, CEM, and murine tumor cell line L 1210. The ruthenium complexes show promising biological activity especially in decreasing tumor volume and viable ascitic cell counts. These complexes prolonged the life span of mice bearing EAC tumors by 10–52%. In vitro evaluation of these ruthenium complexes revealed cytotoxic activity from 0.29 to 2.9?µmol?L^?1 against Molt 4/C₈, 0.22 to 2.1?µmol?L^?1 against CEM and 0.42 to 4.7?µmol?L^?1 against L1210 cell proliferation, depending on the nature of the compound. The metal complexes are more active than the parent ligand and exhibit mild to moderate antibacterial activity.     

Synthesis of novel xanthone and acridone carboxamides with potent antiproliferative activities

Several new amino-substituted acridone and xanthone derivatives have been designed and synthesized, using an efficient methodology from suitable acridone- or xanthone-carboxylic acid intermediates. The antiproliferative activity of the target compounds has been evaluated against four cancer cell lines, namely breast adenocarcinoma MCF-7, acute lymphocytic leukemia CCRF-CEM, and its doxorubicin-resistant variant CEM/ADR5000 and prostate cancer PC-3 cell lines. Selected derivatives have also been tested against the urinary bladder T24 and metastatic melanoma WM266-4 cancer cell lines. Two nitro substituted acridones, bearing a basic side chain as well, were endowed with a remarkable profile against the majority of the cell lines tested, with IC₅₀ values in the low micromolar range. Both compounds cause accumulation at G0/G1 phase, induce apoptosis, and act as potent autophagy inhibitors in PC-3 cells, suggesting their further evaluation in various pathophysiological environments, conditions, and regimens.     

Synthesis and biological evaluation of indoloquinolines and pyridocarbazoles: a new example of unexpected photoreduction accompanying photocyclization

Indoloquinoline alkaloid cryptolepine and pyridocarbazole alkaloid ellipticine are of great interest because in vitro and in vivo studies revealed their good cytotoxic properties. In order to obtain some biologically active analogs of these compounds, we developed a synthesis based on the photocyclization of tertiary N-substituted enaminones derived from 1,3-cyclohexandione and 3 or 6-aminoquinoline. The angular cyclized compounds thus obtained were tested in vitro on K 562 cells and A 2780 doxorubicin sensitive and resistant cells. All compounds were less effective than doxorubicin in sensitive cells but their activity wasn't decreased by MDR resistance.     

Synthesis and Biological Evaluation of RGD Peptidomimetic–Paclitaxel Conjugates Bearing Lysosomally Cleavable Linkers

Two small‐molecule–drug conjugates (SMDCs, 6 and 7 ) featuring lysosomally cleavable linkers (namely the Val–Ala and Phe–Lys peptide sequences) were synthesized by conjugation of the α_vβ₃‐integrin ligand cyclo[DKP–RGD]‐CH₂NH₂ ( 2 ) to the anticancer drug paclitaxel (PTX). A third cyclo[DKP–RGD]–PTX conjugate with a nonpeptide “uncleavable” linker ( 8 ) was also synthesized to be tested as a negative control. These three SMDCs were able to inhibit biotinylated vitronectin binding to the purified α_Vβ₃‐integrin receptor at nanomolar concentrations and showed good stability at pH 7.4 and pH 5.5. Cleavage of the two peptide linkers was observed in the presence of lysosomal enzymes, whereas conjugate 8 , which possesses a nonpeptide “uncleavable” linker, remained intact under these conditions. The antiproliferative activities of the conjugates were evaluated against two isogenic cell lines expressing the integrin receptor at different levels: the acute lymphoblastic leukemia cell line CCRF‐CEM (α_Vβ₃?) and its subclone CCRF‐CEM α_Vβ₃ (α_Vβ₃+). Fairly effective integrin targeting was displayed by the cyclo[DKP–RGD]–Val–Ala–PTX conjugate ( 6 ), which was found to differentially inhibit proliferation in antigen‐positive CCRF‐CEM α_Vβ₃ versus antigen‐negative isogenic CCRF‐CEM cells. The total lack of activity displayed by the “uncleavable” cyclo[DKP–RGD]–PTX conjugate ( 8 ) clearly demonstrates the importance of the peptide linker for achieving the selective release of the cytotoxic payload.     

Takaneones A-C, prenylated butylphloroglucinol derivatives from Hypericum sikokumontanum

Three new prenylated butylphloroglucinol derivatives, takaneones A-C (1-3), were isolated from the MeOH extracts of the aerial parts of Hypericum sikokumontanum together with two new prenylated phloroglucinol derivatives, takaneols A and B (4 and 5). The structures of the isolated compounds were elucidated by exhaustive spectroscopic analysis. The cytotoxicities of the isolated compounds against human cancer cell lines were evaluated. Compounds 2-4 showed cytotoxicities against K562/Adr multi-drug resistant (MDR) cancer cells with IC₅₀ values ranging from 4.7 to 10.0 μg/mL, which were slightly more potent than doxorubicin. Their potency of cytotoxicities against MDR cancer cell lines (KB-C2 and K562/Adr) were similar to those against sensitive cell lines (KB and K562).     

Isobavachalcone as an Active Membrane Perturbing Agent and Inhibitor of ABCB1 Multidrug Transporter

Isobavachalcone (IBC) is an active substance from the medicinal plant Psoralea corylifolia. This prenylated chalcone was reported to possess antioxidative, anti-inflammatory, antibacterial, and anticancer activities. Multidrug resistance (MDR) associated with the over-expression of the transporters of vast substrate specificity such as ABCB1 (P-glycoprotein) belongs to the main causes of cancer chemotherapy failure. The cytotoxic, MDR reversing, and ABCB1-inhibiting potency of isobavachalcone was studied in two cellular models: human colorectal adenocarcinoma HT29 cell line and its resistant counterpart HT29/Dx in which doxorubicin resistance was induced by prolonged drug treatment, and the variant of MDCK cells transfected with the human gene encoding ABCB1. Because MDR modulators are frequently membrane-active substances, the interaction of isobavachalcone with model phosphatidylcholine bilayers was studied by means of differential scanning calorimetry. Molecular modeling was employed to characterize the process of membrane permeation by isobavachalcone. IBC interacted with ABCB1 transporter, being a substrate and/or competitive inhibitor of ABCB1. Moreover, IBC intercalated into model membranes, significantly affecting the parameters of their main phospholipid phase transition. It was concluded that isobavachalcone interfered both with the lipid phase of cellular membrane and with ABCB1 transporter, and for this reason, its activity in MDR cancer cells was presumptively beneficial.     

5-Aminolaevulinic acid-mediated photodynamic therapy in multidrug resistant leukemia cells

To verify if photodynamic therapy (PDT) could overcome multidrug resistance (MDR) when it it applied to eradicate minimal residual disease in patients with leukemia, we investigated the fluorescence kinetics of 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) and the effect of subsequent photodynamic therapy on MDR leukemia cells, which express P-glycoprotein (P-gp), as well as on their parent cells. Evaluation of PpIX accumulation by flow cytometry showed that PpIX accumulated at higher levels in mdr-1 gene-transduced MDR cells (NB4/MDR) and at lower levels in doxorubicin-induced MDR cells (NOMO-1/ADR) than in their parent cells. A P-gp inhibitor could not increase PpIX accumulation. Measurement of extracellular PpIX concentration by fluorescence spectrometry showed that P-gp did not mediate the fluorescence kinetics of ALA-induced PpIX production. Assessment of ferrochelatase activity using high-performance liquid chromatography indicated that PpIX accumulation in drug-induced MDR cells was probably regulated by this enzyme. Assessment of phototoxicity of PDT using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that PDT was effective in NB4, NB4/MDR, NOMO-1 and NOMO-1/ADR cells, which accumulated high levels of PpIX, but not effective in K562 and K562/ADR cell lines, which accumulated relatively low levels of PpIX. These findings demonstrate that P-gp does not mediate the ALA-fluorescence kinetics, and multidrug resistant leukemia cells do not have cross-resistance to ALA-PDT.     

Design,Synthesis, and Evaluation of Tetraethylene Glycol Tethered Isatin–Coumarin Hybrids as Novel Anticancer Agents

Herein, we report the design and synthesis of a new set of tetraethylene glycol tethered isatin–coumarin hybrids 7a – l as anticancer agents. Results revealed that all the synthesized hybrids showed no or weak activities against their in vitro antitumor activities against drug‐sensitive HepG2, Hela, A549, DU145, SKOV3, and MCF‐7 as well as drug‐resistant MCF‐7/DOX (doxorubicin‐resistant MCF‐7) human cancer cell lines. The structure–activity relationship was also discussed, and the enriched structure–activity relationship may pave the way for further rationale design of this kind of hybrids.