Costunosides A-C: cytotoxic sesquiterpene lactones from the rhizomes of Aucklandia costus Falc.

Three new eudesmane type rare sesquiterpene lactone galactosides, costunosides A-C (1-3) were isolated from the rhizomes of Aucklandia costus along with ten known compounds (4-13). Costunosides A-C (1-3) are the first example of naturally eudesmane glycosides containing a ß-galactopyranoside moiety. The structure and relative configurations of these compounds were established by comprehensive analysis of MS and, in particular 1D/2D NMR spectroscopic data. The isolated compounds were tested against a panel of human cancer cell lines, where compounds 3, 6 and 7 have shown promising cytotoxic activity against PC-3, HCT-116 and A549 cell lines with IC50 values in the range of 3.4 µM to 9.3 µM, respectively. Costunosides A-C (1-3) were also screened for inhibition assay of acetyl-cholinesterase (AChE), and butyrylcholinesterase (BChE) and found inactive at a concentration of 10 µM.

Apoptotic Potential and Antitumor Efficacy of Trilliumoside A: A New Steroidal Saponin Isolated from Rhizomes of Trillium govanianum.

Natural product-derived molecules exhibit potential as anticancer agents. Trilliumoside A, a new steroidal saponin, was obtained from rhizomes of Trillium govanianum, and its anticancer activity was investigated in the presented study. Trilliumoside A was investigated in a panel of cell lines, and it exhibited promising cytotoxic activity on the A549 cells (human lung cancer cells) with an IC50 of 1.83 µM. The mechanism of cell death induced by Trilliumoside A in A549 cells and its anticancer potential in murine tumor models (EAC and EAT) were presented in the current research. Trilliumoside A was found to induce apoptosis in A549 cells by increasing the expression of various apoptotic proteins, such as Bax, Puma, cytochrome C, cleaved PARP, and cleaved caspase 3. Additionally, Trilliumoside A regulates the expression of p53, CDK2, and Cyclin A by decreasing the mitochondrial membrane potential, elevating reactive oxygen species, and stopping the growth of A549 cells in the synthesis phase (S) of the cell cycle. Trilliumoside A showed a considerable reduction in the tumor volume, the amount of ascitic fluid, and the total cell number without affecting the body weight of animals. Our results demonstrate that Trilliumoside A inhibits the proliferation of human lung cancer cells by inducing DNA damage, arresting the cell cycle, and activating the mitochondrial signaling pathway. The study demonstrated the potential of Trilliumoside A as a potential anticancer agent.

Antifibrotic Agent Mediated Tumor Microenvironment Modulation and Improved Nanomedicine Delivery in Solid Tumor.

The unique physiology of tumors limits the efficacy of chemotherapeutics. In efforts to improve the effectiveness of the existing chemotherapy drugs, nanomedicine emerged as a new hope but proved inadequate due to the transport barriers present within the tumor tissues, which limits the potential of nanomedicine. Dense collagen networks in fibrotic tissues contribute to hindering the penetration of molecular- or nano-scale medicine through tumor interstitium. In the present study, human serum albumin (HSA)-based nanoparticles (NPs) were developed for gemcitabine (GEM) and losartan (LST), which could offer secreted protein acids rich in cysteine (SPARC) and enhanced permeability and retention effect (EPR)-mediated drug accumulation in tumors. Also, the tumor microenvironment (TME) modulation approach using LST was coupled to investigate the impact on antitumor efficacy. GEM-HSA NPs and LST-HSA NPs were prepared by the desolvation-cross-linking method and characterized for size, potential, morphology, drug loading, drug-polymer interactions, and hemocompatibility. For investigating the efficacy of prepared NPs, cytotoxicity and mechanisms of cell death were elucidated in vitro by using various assays. Intracellular uptake studies of prepared HSA NPs indicated their uptake and cytoplasmic localization. Furthermore, in vivo studies demonstrated significantly improved anticancer efficacy of GEM-HSA NPs in combination with LST pretreatment. Extended LST treatment further improved the anticancer potential. It was shown that the improved efficacy of the nanomedicine was correlated with the reduced thrombospondin-1 (TSP-1) and collagen level in tumor tissue upon LST pretreatment. Moreover, this approach exhibited augmented nanomedicine accumulation in the tumor, and hematological, biochemical, and tissue histology indicated the safety profile of this combination regimen. Concisely, the undertaken study demonstrated the potential of the triple targeting (SPARC, EPR, TME modulation) approach for augmented efficacy of chemotherapeutics.

In vitro and in vivo anticancer potential and molecular targets of the new colchicine analog IIIM-067.

OBJECTIVE: The current study evaluated various new colchicine analogs for their anticancer activity and to study the primary mechanism of apoptosis and in vivo antitumor activity of the analogs with selective anticancer properties and minimal toxicity to normal cells. METHODS: Sulforhodamine B (SRB) assay was used to screen various colchicine analogs for their in vitro cytotoxicity. The effect of N-[(7S)-1,2,3-trimethoxy-9-oxo-10-(pyrrolidine-1-yl)5,6,7,9-tetrahydrobenzo[a] heptalene-7-yl] acetamide (IIIM-067) on clonogenicity, apoptotic induction, and invasiveness of A549 cells was determined using a clonogenic assay, scratch assay, and staining with 4',6-diamidino-2-phenylindole (DAPI) and annexin V/propidium iodide. Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) levels were observed using fluorescence microscopy. Western blot analysis was used to quantify expression of proteins involved in apoptosis, cell cycle, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling. Pharmacokinetic and in vivo efficacy studies against Ehrlich ascites carcinoma (EAC) and Ehrlich solid tumor models were conducted using Swiss albino mice. RESULTS: IIIM-067 showed potent cytotoxicity and better selectivity than all other colchicine analogs screened in this study. The selective activity of IIIM-067 toward A549 cells was higher among other cancer cell lines, with a selectivity index (SI) value of 2.28. IIIM-067 demonstrated concentration- and time-dependent cytotoxicity against A549 cells with half-maximal inhibitory concentration values of 0.207, 0.150 and 0.106 µmol/L at 24, 48 and 72 h, respectively. It also had reduced toxicity to normal cells (SI > 1) than the parent compound colchicine (SI = 1). IIIM-067 reduced the clonogenic ability of A549 cells in a dose-dependent manner. IIIM-067 enhanced ROS production from 24.6% at 0.05 µmol/L to 82.1% at 0.4 µmol/L and substantially decreased the MMP (100% in control to 5.6% at 0.4 µmol/L). The annexin V-FITC assay demonstrated 78% apoptosis at 0.4 µmol/L. IIIM-067 significantly (P < 0.5) induced the expression of various intrinsic apoptotic pathway proteins, and it differentially regulated the PI3K/AKT/mTOR signaling pathway. Furthermore, IIIM-067 exhibited remarkable in vivo anticancer activity against the murine EAC model, with tumor growth inhibition (TGI) of 67.0% at a dose of 6 mg/kg (i.p.) and a reduced mortality compared to colchicine. IIIM-067 also effectively inhibited the tumor growth in the murine solid tumor model with TGI rates of 48.10%, 55.68% and 44.00% at doses of 5 mg/kg (i.p.), 6 mg/kg (i.p.) and 7 mg/kg (p.o.), respectively. CONCLUSION: IIIM-067 exhibited significant anticancer activity with reduced toxicity both in vitro and in vivo and is a promising anticancer candidate. However, further studies are required in clinical settings to fully understand its potential.

Implication of methylselenocysteine in combination chemotherapy with gemcitabine for improved anticancer efficacy.

The limitations associated with cancer monotherapy including dose dependent toxicity and drug resistance can be addressed by combination chemotherapy. The combination of antineoplastic agents improves the cytotoxic activity in comparison to the single-agent based therapy in a synergistic or an additive mode by reducing tumor growth as well as metastatic ability. In the present investigation, we explored the potential of methylselenocysteine (MSC) in combination chemotherapy with gemcitabine (GEM). The cytotoxic activity of GEM and MSC was determined in various cell lines and based on the activity, A549 cells were explored for the mechanistic studies including DAPI staining, measurement of oxidative stress, mitochondrial membrane potential loss, nitric oxide level, western blotting, cell migration and colony formation assays. A549 cells in combination treatment with MSC and GEM demonstrated enhanced cytotoxicity with more irregular cellular morphology as well as chromatin condensation and nuclear blebbing. The selected combination also significantly triggered ROS generation and mitochondrial destabilization, and alleviated cell migration potential and clonogenic propensity of A549 cells. Also, caspase-3 and PARP mediated apoptosis was observed in the combination treated cells. MSC based drug combination could offer the attributes of improved drug delivery and there was a 6-folds dose reduction of GEM in combination. Further, antitumor study in Ehrlich solid tumor model showed the efficacy of MSC combination with GEM for the enhanced antitumor activity. The proposed combination demonstrated the potential for further translational studies.

An improved synthesis of indanocine and antiproliferative activity of 2-benzylindanocine via microtubule destabilization.

Indanocine, a potent anticancer investigational drug of National Cancer Institute-USA, has been much discussed in recent years. Present communication aimed at total synthesis of indanocine and its close analogues. Total synthesis was improved by double yields than previously reported yields. Some of the benzylidene and 2-benzyl derivatives with free rotation at C2 position exhibited potential cytotoxicities against various human cancer cell lines. Five such analogues exhibited potential antiproliferative effect against HCT-116 and MIA PACA-2 cell lines. Benzylindanocine 12i induced microtubule destabilization by occupying colchicine binding pocket of ß-tubulin. It also exhibited anti-inflammatory activity by down-regulating IL-6 and TNF-α. In Ehrlich ascites carcinoma model, 12i reduced 78.4% of EAC tumour in Swiss albino mice at 90 mg/kg (i.p.) dose. Further, in in vivo safety studies, 12i was found to be safe to rodents up to 1,000 mg/kg dose. Concomitant anticancer and anti-inflammatory activity of benzylindanocine is distinctive, which suggests its further optimization for better efficacy and druggability.

Binary and ternary solid dispersions of an anticancer preclinical lead, IIIM-290: In vitro and in vivo studies.

The objective of this study was to formulate an anticancer preclinical lead, IIIM-290, loaded in solid dispersions to enhance its solubility, dissolution, and oral pharmacokinetics. IIIM-290 is an in-house preclinical anticancer lead prepared by semisynthetic modification of the natural product rohitukine. It is an orally bioavailable Cdk inhibitor showing efficacy in xenograft models of pancreatic, colon and leukemia cancer. It demonstrated in vivo efficacy at a relatively higher dose owing to its poor aqueous solubility (~8.6 µg/mL). Binary and ternary solid dispersions containing PVP K-30, xanthan gum, and PEG-PPG-PEG were selected after solubility screening of various hydrophilic polymers. Several formulations with varying ratios of polymers, alone and in combination, were prepared and investigated for their effects on the solubility enhancement of IIIM-290. The binary solid dispersion VKB-SD75, prepared with PVP K-30 at the ratio of 1:4 w/w, was identified as the optimized composition that displayed 17-fold improvement in the aqueous solubility of IIIM-290. VKB-SD75 was scaled up to a 100-g scale. IIIM-290 and VKB-SD75 were evaluated for DSC, p-XRD, FTIR, 1H NMR, SEM, in vitro dissolution, and oral pharmacokinetics, as well as for in vivo anticancer activity in the Ehrlich solid tumor model. The oral administration of VKB-SD75 in BALB/c mice resulted in a 1.9-fold improvement in plasma exposure. These findings also correlated well when the formulation was administered to mice in the Ehrlich solid tumor model. The newly developed solid dispersion is expected to reduce the dose of IIIM-290 by ~40-50% in preclinical and clinical studies.

Gemcitabine and betulinic acid co-encapsulated PLGA-PEG polymer nanoparticles for improved efficacy of cancer chemotherapy.

The present study demonstrated the development of gemcitabine and betulinic acid co-encapsulated PLGA-PEG polymer nanoparticles for enhancing the chemotherapeutic response. This combinatorial PLGA-PEG nanoparticle was formulated using double emulsion and had size <200 nm. The developed nanoparticles were characterized using dynamic light scattering and transmission electron microscopy for their size and shape, respectively. The in vitro release of the drugs from combinatorial nanoparticles was predominantly followed by Fickian diffusion phenomenon. Study on hemocompatibilty approved the administration of this combinatorial nanoparticle for animal study. In vitro cytotoxicity study on Panc1 cells using MTT assay, reactive oxygen species production and cellular apoptotic assay demonstrated that combinatorial nanoparticle was more cytotoxic compared to native drugs solution. Furthermore, the combinatorial nanoparticle suppressed tumor growth more efficiently in Ehrlich (solid) tumor model than the native gemcitabine and betulinic acid at the same concentrations. These findings indicated that PLGA-PEG nanoparticle might be used to co-deliver multiple chemotherapeutic drugs with different properties for enhancing antitumor efficacy.

Synthesis and Investigation of the Role of Benzopyran Dihydropyrimidinone Hybrids in Cell Proliferation, Migration and Tumor Growth.

BACKGROUND: Cancer is the second leading cause of mortality worldwide after heart diseases, and lung cancer is the topmost cause of all cancer-related deaths in both sexes. Dihydropyrimidinones (DHPMs) are medicinally important class of molecules with diverse pharmacological activities including anticancer activity. The present study focuses on the molecular hybridization of novel Benzopyran with Dihydropyrimidinone and evaluation of the resulting hybrids for cancer cell proliferation, migration and tumor growth. METHODS: We have synthesized a focused library of dihydropyrimidinone benzopyran hybrids (compounds 1-11) by joining the aromatic as well as pyran portions of the benzopyran core with dihydropyrimidinone. All the synthesized hybrid molecules were evaluated for their cytotoxic activities against a panel of four human cancer cell lines of diverse tissue origin, viz: A549 (lung carcinoma), MCF7 (mammary gland adenocarcinoma), HCT-116 (colorectal carcinoma), and PANC-1 (pancreatic duct carcinoma) with the help of MTT cell viability assay. A structure-activity relationship was made on the basis of IC50 values of different hybrids. Effect on cell proliferation was examined through colony formation assay, reactive oxygen species generation and mitochondrial membrane potential studies. Wound healing assays and cell scattering assays were employed to check the effect on cell migration. Western blotting experiments were performed to find out the molecular mechanism of action and anti-tumor studies were carried out to evaluate the in vivo efficacy of the selected lead molecule. RESULTS: Two types of novel hybrids were synthesized efficiently from benzopyran aldehydes, ethylacetoacetate and urea under heteropolyacid catalysis. Compound 3 was found to be the most potent hybrid among the synthesized compounds with consistent cytotoxic activities against four human cancer cell lines (IC50 values: 0.139 - 2.32 µM). Compound 3 strongly inhibited proliferation abilities of A549 cells in colony formation assay. Compound 3 exerted oxidative stress-mediated mitochondrial dysfunction, in which mitochondrial reactive oxygen species (ROS) generation as a mechanism of its anti-proliferative effects was analysed. Further, the molecule abrogated migration and cell scattering properties of aggressive PANC-1 cells. Mechanistic studies revealed that compound 3 modulated NF-kB expression and its downstream oncogenic proteins involved in cancer cell proliferation and invasion. Finally, compound 3 confirmed its in vivo anti-tumor efficacy; there observed 41.87% tumor growth inhibition at a dose of 30 mg/kg/body weight against a mouse model of Ehrlich solid tumor. CONCLUSION: Our study unravels a potential anticancer lead (compound 3) from DHPMs that have opened up new research avenues for the development of promising anticancer therapeutic agents.

Antitumour, acute toxicity and molecular modeling studies of 4-(pyridin-4-yl)-6-(thiophen-2-yl) pyrimidin-2(1H)-one against Ehrlich ascites carcinoma and sarcoma-180.

In an effort to discover an effective and selective antitumour agent, synthesis and anti-cancer potential of 4-(pyridin-4-yl)-6-(thiophen-2-yl) pyrimidin-2(1H)-one (SK-25), which has been reported earlier by us with significant cytotoxicity towards MiaPaCa-2 malignant cells, with an IC50 value of 1.95 µM and was found to instigate apoptosis. In the present study, the antitumour efficacy of SK-25 was investigated on Ehrlich ascites tumour (EAT, solid), Sarcoma 180 (solid) tumour and Ehrlich ascites carcinoma. The compound was found to inhibit tumour development by 94.71% in Ehrlich ascites carcinoma (EAC), 59.06% in Ehrlich tumour (ET, solid) and 45.68% in Sarcoma-180 (solid) at 30 mg/kg dose. Additionally, SK-25 was established to be non-toxic at a maximum tolerated dose of 1000 mg/kg in acute oral toxicity in Swiss-albino mice. Computer-based predictions also show that the compounds could have an interesting DMPK profile since all 51 computed physicochemical parameters fall within the recommended range for 95% of known drugs. The current study provides insight for further investigation of the antitumour potential of the molecule.

Discovery and Preclinical Development of IIIM-290, an Orally Active Potent Cyclin-Dependent Kinase Inhibitor.

Rohitukine (1), a chromone alkaloid isolated from Indian medicinal plant Dysoxylum binectariferum, has inspired the discovery of flavopiridol and riviciclib, both of which are bioavailable only via intravenous route. With the objective to address the oral bioavailability issue of this scaffold, four series of rohitukine derivatives were prepared and screened for Cdk inhibition and cellular antiproliferative activity. The 2,6-dichloro-styryl derivative IIIM-290 (11d) showed strong inhibition of Cdk-9/T1 (IC50 1.9 nM) kinase and Molt-4/MIAPaCa-2 cell growth (GI50 < 1.0 µM) and was found to be highly selective for cancer cells over normal fibroblast cells. It inhibited the cell growth of MIAPaCa-2 cells via caspase-dependent apoptosis. It achieved 71% oral bioavailability with in vivo efficacy in pancreatic, colon, and leukemia xenografts at 50 mg/kg, po. It did not have CYP/efflux-pump liability, was not mutagenic/genotoxic or cardiotoxic, and was metabolically stable. The preclinical data presented herein indicates the potential of 11d for advancement in clinical studies.

Development and characterization of hyaluronic acid modified PLGA based nanoparticles for improved efficacy of cisplatin in solid tumor.

Cisplatin is a potent and widely used chemotherapeutic agent to treat a variety of tumors. However, its clinical use is associated with undesirable side effects and acquired resistance to cisplatin. In this study, cisplatin loaded hyaluronic acid (HA) functionalized poly (lactic-co-glycolic acid)-poly (ethylene glycol) nanoparticles (CP-HA-PLGA-PEG-NPs) were fabricated using double emulsion solvent evaporation method to target CD44 receptor expressed on cancerous cells. The developed nanoconstructs were characterized for various in vitro parameters, including size distribution, zeta potential, morphology, drug loading and in vitro release. The HA content on the HA-PLGA-PEG-NPs was quantified by a turbidimetric method. The in vitro anticancer study in human ovarian cancer (SKOV-3) cells showed significantly (p<0.05) higher cytotoxicity of CP-HA-PLGA-PEG NPs as compared to free cisplatin and non-targeted nanoparticles (CP-PLGA-PEG NPs). Further, laser scanning confocal microscopy revealed that there was enhanced cellular uptake of HA-PLGA-PEG NPs in CD44-over expressing ovarian cancer cell line (SKOV-3). The in vivo antitumor activity of CP-HA-PLGA-PEG-NPs was significantly (p<0.05) higher than free cisplatin and CP-PLGA-PEG-NPs in Ehrlich tumor (solid) bearing mice. The results demonstrated the potential of target specific nanoconstruct of cisplatin in the improved cancer chemotherapy.

Development and evaluation of long-circulating nanoparticles loaded with betulinic acid for improved anti-tumor efficacy.

The clinical application of betulinic acid (BA), a natural pentacyclic triterpenoid with promising antitumor activity, is hampered due to its extremely poor water solubility and relatively short half-life in the systemic circulation. In order to address these issues, herein, we developed betulinic acid loaded polylactide-co-glycolide- monomethoxy polyethylene glycol nanoparticles (PLGA-mPEG NPs). The PLGA-mPEG co-polymer was synthesized and characterized using NMR and FT-IR. BA loaded PLGA-mPEG NPs were prepared by an emulsion solvent evaporation method. The developed nanoparticles had a desirable particle size (∼147nm) and exhibited uniform spherical shape under transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The PLGA-mPEG NPs were able to decrease the uptake by macrophages (i.e. J774A.1 and Raw 264.7 cells) as compared to PLGA nanoparticles. In vitro cytotoxicity in MCF7 and PANC-1 cells demonstrated enhanced cytotoxicity of BA loaded PLGA-mPEG NPs as compared to free BA. The cellular uptake study in both the cell lines demonstrated time dependent uptake behavior. The enhanced cytotoxicity of BA NPs was also supported by increased cellular apoptosis, mitochondrial membrane potential loss, generation of high reactive oxygen species (ROS) and cell cycle arrest. Further, intravenous pharmacokinetics study revealed that BA loaded PLGA-mPEG NPs could prolong the circulation of BA and remarkably enhance half-life by ∼7.21 folds. Consequently, in vivo studies in Ehrlich tumor (solid) model following intravenous administration demonstrated superior antitumor efficacy of BA NPs as compared to native BA. Moreover, BA NPs treated Ehrlich tumor mice demonstrated no biochemical, hematological and histological toxicities. These findings collectively indicated that the BA loaded PLGA-mPEG NPs might serve as a promising nanocarrier for improved therapeutic efficacy of betulinic acid.

A marine sponge alkaloid derivative 4-chloro fascaplysin inhibits tumor growth and VEGF mediated angiogenesis by disrupting PI3K/Akt/mTOR signaling cascade.

Tumor angiogenesis and PI3K/Akt/mTOR pathway are two major molecular objectives for the treatment and management of breast cancer. Here we first time report the molecular mechanism of a marine sponge alkaloid derivative 4-chloro fascapysin (4-CF) for its anticancer and antiangiogenesis potential. It simultaneously targets multiple cancer and angiogenesis dynamics, such as proliferation, chemotaxis cell migration, and invasion, growth factors signaling cascade, autophagy and apoptosis in HUVEC and MDAMB-231 breast cancer cells. It inhibited the VEGF mediated microvessel sprouting and blood vessel formation in the matrigel plug of C57/BL6J mice. It inhibits the tumor growth in ET (solid) mouse tumor model. It significantly inhibited cell survival through PI3K/Akt/mTOR pathway, with attendant effects on key pro-angiogenesis factors like HIF-1α, eNOS and MMP-2/9. The cytotoxicity of 4-CF was reversed by co-treatment with the VEGF and Akt inhibitors sunitinib and perifosine, respectively or by the addition of neutralizing VEGF antibodies. The apoptotic potential of 4-CF was through mitochondrial dependent as illustrated through loss of mitochondrial membrane potential. The safety profile of 4-CF was acceptable as it exhibits five times high cytotoxic IC50 value in normal cells as well as no apparent toxicities in experimental tumor mice at therapeutic doses.

Synthesis, characterization and augmented anticancer potential of PEG-betulinic acid conjugate.

Betulinic acid (BA), a pentacyclic lupine-type triterpene, is reported to inhibit cell growth in a variety of cancers. However, its efficacy is limited by its poor aqueous solubility and relatively short half-life. In this study, BA-monomethoxy polyethylene glycol (mPEG) conjugate was synthesized by covalent coupling the C-28 carboxylic acid position of BA with amine groups of mPEG, in order to improve its solubility and anticancer efficacy. mPEG-BA conjugate was characterized using various analytical techniques including NMR, FT-IR and MALDI-MS. The mPEG-BA conjugate was cytotoxic, demonstrated internalization and induced cell apoptosis in Hep3B and Huh7 hepatic cancer cells. The western-blot analysis revealed, marked decrease in Bcl-2/Bax ratio, and increase in cleaved-PARP and cleaved-caspase-3 expressions. In vivo studies in Ehrlich ascites tumor (EAT) model following intravenous administration demonstrated significant reduction in tumor volume in case of PEGylated BA as compare to native BA. Furthermore, PEGylated BA treated EAT mice showed no biochemical and histological toxicities. These findings demonstrate the potential of PEGylated BA in cancer therapy, with improved water solubility and efficacy.

IN0523 (Urs-12-ene-3α,24ß-diol) a plant based derivative of boswellic acid protect Cisplatin induced urogenital toxicity.

The limiting factor for the use of Cisplatin in the treatment of different type of cancers is its toxicity and more specifically urogenital toxicity. Oxidative stress is a well-known phenomenon associated with Cisplatin toxicity. However, in Cisplatin treated group, abnormal animal behavior, decreased body weight, cellular and sub-cellular changes in the kidney and sperm abnormality were observed. Our investigation revealed that Cisplatin when administered in combination with a natural product derivative (Urs-12-ene-3α,24ß-diol, labeled as IN0523) resulted in significant restoration of body weight and protection against the pathological alteration caused by Cisplatin to kidney and testis. Sperm count and motility were significantly restored near to normal. Cisplatin caused depletion of defense system i.e. glutathione peroxidase, catalase and superoxide dismutase, which were restored close to normal by treatment of IN0523. Reduction in excessive lipid peroxidation induced by Cisplatin was also found by treatment with IN0523. The result suggests that IN0523 is a potential candidate for ameliorating Cisplatin induced toxicity in the kidney and testes at a dose of 100mg/kg p.o. via inhibiting the oxidative stress/redox status imbalance and may be improving the efflux mechanism.

Potential anticancer role of colchicine-based derivatives: an overview.

Colchicine, the main alkaloid of the poisonous plant meadow saffron (Colchicum autumnale L.), is a classical drug used for the treatment of gout and familial Mediterranean fever. Although colchicine is not clinically used to treat cancer because of toxicity, it exerts antiproliferative effects through the inhibition of microtubule formation by blocking the cell cycle at the G2/M phase and triggering apoptosis. Colchicine can still be used as a lead compound for the generation of potential anticancer drugs. Thus, numerous analogues of colchicine have been synthesized in the hope of developing novel, useful drugs with more favourable pharmacological profiles. Several colchicine semisynthetics are less toxic than colchicine and research is being carried out on effective, less toxic colchicine semisynthetic formulations with potential drug-delivery strategies directly targeting multiple solid cancers. This review focuses on the anticancer role of some of colchicine-based derivatives and their therapeutic importance.

6-Aryl substituted 4-(4-cyanomethyl) phenylamino quinazolines as a new class of isoform-selective PI3K-alpha inhibitors.

Isoform-selective inhibition of PI3K-α has been identified as one of the important strategy to discover effective and safer anticancer agents. Herein, we report discovery of 'quinazoline' as a new chemotype for isoform-selective PI3K-α inhibitors. The indolyl substituted quinazoline 9u displayed selective inhibition of PI3K-α with IC50 value of 0.201 µM with >49.7 over PI3K-ß, and δ-isoforms. Quinazoline 9u also inhibited PI3K-γ with IC50 value of 0.750 µM (3.7 fold selective for α-versus γ-isoform). The isoform-selective inhibition was also demonstrated at protein-expression level by western-blot analysis in MCF-7 and PC-3 cells. The isoform-selective inhibitor 9u also showed inhibition of phospho-Akt levels in these cells. Quinazoline 9u showed in-vitro cytotoxicity in MCF-7 cells with GI50 of 7 µM, which was highly selective for cancer cells, as it was non-toxic to normal cells fR2, HEK293 and hGF (GI50 > 50 µM). Compound 9u at 25 mg/kg dose showed 62 and 37% TGI in Ehrlich Ascites Carcinoma and Ehrlich Solid Tumor mice models. In nutshell, our efforts to identify potent and efficacious PI3K inhibitors resulted in the discovery of a new class of isoform-selective PI3K-α inhibitors possessing promising in-vivo anticancer activity.

Long-circulatory nanoparticles for gemcitabine delivery: Development and investigation of pharmacokinetics and in-vivo anticancer efficacy.

The anticancer potential of gemcitabine, a nucleoside analog, is compromised due to the enzymatic degradation into inactive form leading to the short half-life in systemic circulation. Novel delivery strategies are required to improve therapeutic efficacy of this potential drug. Monomethoxy polyethylene glycol amine-polylactide-co-glycolide (mPEG-PLGA) co-polymer was synthesized and characterized by FTIR and (1)H NMR. Gemcitabine loaded mPEG-PLGA nanoparticles (NPs) were developed and investigated for pharmacokinetic profile and in vivo anticancer activity. The mPEG-PLGA NPs (size: 267±10nm, zeta potential: -17.5±0.2mV) exhibited sustained drug release profile and were found to be compatible with blood. The mPEG-PLGA NPs were able to evade the uptake by macrophages (i.e. THP-1 and J774A) by reducing the adsorption of proteins on the surface of NPs. The enhanced cellular uptake and cell cytotoxicity was observed by mPEG-PLGA NPs in MiaPaCa-2 and MCF-7 cells. The half-life of gemcitabine in mPEG-PLGA NPs was remarkably enhanced (19 folds) than native gemcitabine. Further, the pharmacokinetic modulation of gemcitabine using mPEG-PLGA-NPs was translated in improved anticancer efficacy as compared to native gemcitabine in Ehrlich ascites bearing Balb-c mice. The results demonstrated the potential of long-circulatory nanoparticles in improving the pharmacokinetic profile and in-turn the anticancer efficacy of gemcitabine.

A novel colchicine-based microtubule inhibitor exhibits potent antitumor activity by inducing mitochondrial mediated apoptosis in MIA PaCa-2 pancreatic cancer cells.

Colchicine, an antimitotic alkaloid isolated from Colchicum autumnale, is a classical drug for treatment of gout and familial Mediterranean fever. It causes antiproliferative effects through the inhibition of microtubule formation, which leads to mitotic arrest and cell death by apoptosis. Here, we report that a novel colchicine analog, 4o (N-[(7S)-1,2,3-trimethoxy-9-oxo-10-[3-(trifluoromethyl)-4-chlorophenylamino]-5,6,7,9-tetrahydrobenzo[a]heptalen-7-yl]acetamide), which exhibited potent anticancer activities both in vitro and in vivo. In this study, 4o with excellent pharmacokinetic profile and no P-gp induction liability displayed strong inhibition of proliferation against various human cancer cell lines. However, pancreatic cancer cell line MIA PaCa-2 was found to be more sensitive towards 4o and showed strong inhibition in concentration and time-dependent manner. By increasing intracellular reactive oxygen species (ROS) levels, 4o induced endoplasmic reticular stress and mitochondrial dysfunction in MIA PaCa-2 cells. Blockage of ROS production reversed 4o-induced endoplasmic reticulum (ER) stress, calcium release, and cell death. More importantly, it revealed that increased ROS generation might be an effective strategy in treating human pancreatic cancer. Further 4o treatment induced mitotic arrest, altered the expression of cell cycle-associated proteins, and disrupted the microtubules in MIA PaCa-2 cells. 4o treatment caused loss of mitochondrial membrane potential, cytochrome c release, upregulation of Bax, downregulation of Bcl-2, and cleavage of caspase-3, thereby showing activation of mitochondrial mediated apoptosis. The in vivo anticancer activity of the compound was studied using sarcoma-180 (ascitic) and leukemia (P388 lymphocytic and L1210 lymphoid) models in mice and showed promising antitumor activity with the least toxicity unlike colchicine. Such studies have hitherto not been reported. Taken together, these findings highlighted that 4o, a potent derivative of colchicine, causes tumor regression with reduced toxicity and provides a novel anticancer candidate for the therapeutic use.