Co-encapsulated nanoparticles of Erlotinib and Quercetin for targeting lung cancer through nuclear EGFR and PI3K/AKT inhibition.

Erlotinib-based EGFR targeted therapy has proven significant clinical improvement against non-small cell lung cancer (NSCLC). However, the anticancer activity of Erlotinib (Ertb) is limited by the development of Ertb resistance and possess a challenge to clinicians and patients. To explore a better therapeutic strategy, we evaluated Ertb in combinations with different natural products. We identified that Ertb and Quercetin (Quer) combination is more synergistic against A549 and NCI H460 cells compared to Ertb with Fisetin/Carnosic acid/Luteolin. To further improve the efficacy and overcome the limitation of free therapeutics, Ertb and Quer loaded solid lipid nanoparticles (EQNPs) were prepared using Chitosan-MA-TPGS polymer by hot homogenization method. The drug-loaded nanoparticles (NPs) have shown high encapsulation efficiency (77% Ertb and 71.4% Quer) as well as small particle size of 87.3 ± 0.78 nm and positive zeta potential + 13.4 ± 1.12 mV. At pH 5.5, Ertb and Quer were released at their highest levels. We found that, EQNPs decreased the expression of P-glycoprotein (P-gp) and nuclear epidermal growth factor receptor (nEGFR). EQNPs increased the uptake of Ertb and Quer, and apoptosis induction in Ertb resistant A549/ER cells. Further, in vivo EQNPs formulation have shown increased uptake of nanoparticles in the lung tissue and significantly reduced the expression of nEGFR. Thus, EQNPs may be developed as a targeted medicine with minimum side effects for treatment of NSCLC to improve the quality of life and survival of NSCLC patients.

Novel diindoloazepinone derivatives as DNA minor groove binding agents with selective topoisomerase I inhibition: Design, synthesis, biological evaluation and docking studies.

We present here-in the molecular design and chemical synthesis of a novel series of diindoloazepinone derivatives as DNA minor groove binding agents with selective topoisomerase I inhibition. The in vitro cytotoxicity of the synthesized compounds was evaluated against four human cancer cell lines including DU143, HEPG2, RKO and A549 in addition to non-cancerous immortalized human embryonic kidney cells (HEK-293). Compound 11 showed significant cytotoxicity against all the four human cancer cell lines with IC50 values ranging from 4.2 to 6.59 µM. 11 was also found to display 13-fold selective cytotoxicity towards A549 cancerous cells compared to the non-cancerous cell lines (HEK-293). The decatenation, DNA relaxation and intercalation assays revealed that the investigational compounds 10 and 11 act as highly selective inhibitors of Topo-I with DNA minor groove binding ability which was also supported by the results obtained from circular dichroism (CD), UV-visible spectroscopy and viscosity studies. Apoptosis induced by the lead 11 was observed using morphological observations, AO/EB and DAPI staining procedures. Further, dose-dependent increase in the depolarization of mitochondrial membrane was also observed through JC-1 staining. Annexin V-FITC/PI assay confirmed that 11 induced early apoptosis. Additionally, cell cycle analysis indicated that the cells were arrested at sub-G1 phase. Gratifyingly, in silico studies demonstrated promising interactions of 11 with the DNA and Topo I, thus supporting their potential DNA minor groove binding property with relatively selective Topo I inhibition compared to Topo II.

Discovery of certain benzyl/phenethyl thiazolidinone-indole hybrids as potential anti-proliferative agents: Synthesis, molecular modeling and tubulin polymerization inhibition study.

A series of certain benzyl/phenethyl thiazolidinone-indole hybrids were synthesized for the study of anti-proliferative activity against A549, NCI-H460 (lung cancer), MDA-MB-231 (breast cancer), HCT-29 and HCT-15 (colon cancer) cell lines by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). We found that compound G37 displayed highest cytotoxicity with IC50 value of 0.92 ±â€¯0.12 µM towards HCT-15 cancer cell line among all the synthesized compounds. Moreover, compound G37 was also tested on normal human lung epithelial cells (L132) and was found to be safe in contrast to HCT-15 cells. The lead compound G37 showed significant G2/M phase arrest in HCT-15 cells. Additionally, compound G37 significantly inhibited tubulin polymerization with IC50 value of 2.92 ±â€¯0.23 µM. Mechanistic studies such as acridine orange/ethidium bromide (AO/EB) dual staining, DAPI nuclear staining, annexinV/propidium iodide dual staining, clonogenic growth inhibition assays inferred that compound G37 induced apoptotic cell death in HCT-15 cells. Moreover, loss of mitochondrial membrane potential with elevated intracellular ROS levels was observed by compound G37. These compounds bind at the active pocket of the α/ß-tubulin with higher number of stable hydrogen bonds, hydrophobic and arene-cation interactions confirmed by molecular modeling studies.

Nimbolide protects against endotoxin-induced acute respiratory distress syndrome by inhibiting TNF-α mediated NF-κB and HDAC-3 nuclear translocation.

Acute respiratory distress syndrome (ARDS) is characterized by an excessive acute inflammatory response in lung parenchyma, which ultimately leads to refractory hypoxemia. One of the earliest abnormalities seen in lung injury is the elevated levels of inflammatory cytokines, among them, the soluble tumor necrosis factor (TNF-α) has a key role, which exerts cytotoxicity in epithelial and endothelial cells thus exacerbates edema. The bacterial lipopolysaccharide (LPS) was used both in vitro (RAW 264.7, THP-1, MLE-12, A549, and BEAS-2B) and in vivo (C57BL/6 mice), as it activates a plethora of overlapping inflammatory signaling pathways involved in ARDS. Nimbolide is a chemical constituent of Azadirachta indica, which contains multiple biological properties, while its role in ARDS is elusive. Herein, we have investigated the protective effects of nimbolide in abrogating the complications associated with ARDS. We showed that nimbolide markedly suppressed the nitrosative-oxidative stress, inflammatory cytokines, and chemokines expression by suppressing iNOS, myeloperoxidase, and nitrotyrosine expression. Moreover, nimbolide mitigated the migration of neutrophils and mast cells whilst normalizing the LPS-induced hypothermia. Also, nimbolide modulated the expression of epigenetic regulators with multiple HDAC inhibitory activity by suppressing the nuclear translocation of NF-κB and HDAC-3. We extended our studies using molecular docking studies, which demonstrated a strong interaction between nimbolide and TNF-α. Additionally, we showed that treatment with nimbolide increased GSH, Nrf-2, SOD-1, and HO-1 protein expression; concomitantly abrogated the LPS-triggered TNF-α, p38 MAPK, mTOR, and GSK-3ß protein expression. Collectively, these results indicate that TNF-α-regulated NF-κB and HDAC-3 crosstalk was ameliorated by nimbolide with promising anti-nitrosative, antioxidant, and anti-inflammatory properties in LPS-induced ARDS.

LC/QTOF/MS/MS characterization, molecular docking and in silico toxicity prediction studies on degradation products of anagliptin.

Pharmaceutical drugs are potential molecules with specific biological activity. However, long-term use of these chemical molecules can affect the human physiological system because of their increased levels in the human body. Therefore, identification and structure elucidation of impurities or degradation products should be taken into consideration in order to assure drug safety. The present study assessed the degradation behaviour of dipeptidyl peptidase-4 (DPP-4) inhibitor anagliptin under different stress conditions as per ICH guidelines Q1A (R2) followed by elucidation of the structure of degradation products. All the stress samples were analysed by using UPLC/PDA. The superior separation of drug from its degradation products was attained with time programmed gradient elution on BEH C18 (100 mm × 2.1 mm, 1.7 µm) column using 10 mM ammonium formate (aqueous) and acetonitrile (organic) as the mobile phase components. All the degradation products of anagliptin were characterized using LC/QTOF/MS/MS. In addition, the activity and toxicity of degradation products were determined through molecular docking and in silico toxicity prediction studies, respectively. The developed UPLC/PDA method was validated as per ICH guidelines in terms of specificity, accuracy, precision, linearity and robustness.

Synthesis, molecular modeling and evaluation of α-glucosidase inhibition activity of 3,4-dihydroxy piperidines.

Biological evaluation of 3,4-dihydroxy piperidines as α-glucosidase inhibitors is being reported for the first time. Forty-five derivatives (amides, di-amides and sulfonamides) were made using cis and trans 3,4-dihydroxy piperidines to evaluate their α-glucosidase inhibition activity. Polar groups (-OH, -NH2) on phenyl ring having derivatives 5i, 5l, 7g, 7i &12j showed excellent activity compared to standard references. Acarbose, Voglibose and Miglitol were used as standard references. Molecular docking simulations were done for compounds to identify important binding modes responsible for inhibition activity of α-glucosidase.

Synthesis of thiazole linked indolyl-3-glyoxylamide derivatives as tubulin polymerization inhibitors.

A series of thiazole linked indolyl-3-glyoxylamide derivatives were synthesized and evaluated for their in vitro cytotoxic activity against DU145 (prostate), PC-3 (prostate), A549 (lung) and HCT-15 (colon) cancer cell lines by employing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Among all the synthesized compounds, compound 13d displayed cytotoxicity of IC50 = 93 nM towards DU145 cancer cell line. The most active compound 13d was also tested on RWPE-1 cells and was found to be safe compared to the DU145 cells. The target compounds were also evaluated for their inhibition activity of tubulin polymerization. Further, the treatment of compound 13d on DU145 cells led to the inhibition of cell migration ability. The detailed studies such as acridine orange/ethidium Bromide (AO/EB), DAPI, annexin V-FITC/propidium iodide staining assay suggested that the compound 13d induced apoptosis in DU145 cells. The influence of the cytotoxic compound 13d on the cell cycle distribution was assessed on the DU145 cell line, exhibiting a cell cycle arrest at the G2/M phase. Moreover, the treatment with compound 13d caused collapse of mitochondrial membrane potential and elevated intracellular ROS levels in DU145 cells. The results from molecular modelling studies revealed that these compounds bind at the colchicine binding site of the tubulin. Thus, this new molecular scaffold could be a new lead for the development of anticancer agents that target tubulin.

Synthesis and apoptosis inducing studies of triazole linked 3-benzylidene isatin derivatives.

In our venture towards the development of effective cytotoxic agents, a panel of triazole linked 3-benzylidene isatin hybrids were synthesized and characterized by IR, 1H NMR, 13C NMR and Mass spectral analysis. All the newly synthesized target compounds were assessed against DU145 (prostate), PC-3 (prostate), MDA-MB-231 (breast), BT549 (breast), A549 (lung) and HeLa (cervical) human cancer cell lines by employing MTT assay for their cytotoxic potential. Significantly, compound Z-8l was found to be most potent amongst all the tested compounds with an IC50 value of (3.7 ± 0.05 µM) on DU145 cells. The most active compound (Z-8l) was also tested on RWPE-1 (normal prostate) cells and was found to be safe compared to the DU145 cells. The influence of the cytotoxic compound Z-8l on the cell cycle distribution was assessed on the DU145 cell line, exhibiting a cell cycle arrest at the G2/M phase. Additionally, treatment with compound Z-8l caused collapse of mitochondrial membrane potential (DΨm) in DU145 cells. Moreover, acridine orange/ethidium bromide staining, DAPI nuclear staining, DCFDA staining and annexin V binding assay confirmed that compound Z-8l can induce cell apoptosis in DU145 cells. Western blotting was performed to examine the appearance of active forms of cytochrome c, Bax, Bcl2 and PARP (Poly ADP ribose polymerase), indicator proteins of apoptosis in DU145 cells; the study confirmed the triggering of mitochondrial mediated apoptotic pathway upon exposure of compound Z-8l.

Biobased lactams as novel arthropod repellents.

Enanatiomerically pure 4aS,7S,7aR and 4aS,7S,7aS-nepetalactams and their analogs have been prepared in just two steps from 4aS,7S,7aR and 4aS,7S,7aS-nepetalactones, major components of catnip oil. Lactams or cyclic amides from iridoid monoterpenes are generated and being evaluated as a new class of compounds as arthropod deterrents against disease vectors.