Nicotine promotes epithelial to mesenchymal transition and gemcitabine resistance via hENT1/RRM1 signalling in pancreatic cancer and chemosensitizing effects of Embelin-a naturally occurring benzoquinone.

Pancreatic cancer is lethal due to poor prognosis with 5-year survival rate lesser than 5 %. Gemcitabine is currently used to treat pancreatic cancer and development of chemoresistance is a major obstacle to overcome pancreatic cancer. Nicotine is a known inducer of drug resistance in pancreatic tumor micro-environment. Present study evaluates chemoresistance triggered by nicotine while treating with gemcitabine and chemosensitization using Embelin. Embelin is a naturally occurring benzoquinone from Embelia ribes possessing therapeutic potency. To develop nicotine-induced chemo-resistance, pancreatic cancer cells PANC-1 and MIA PaCa-2 were continuously treated with nicotine followed by exposure to gemcitabine. Gemcitabine sensitivity assay and immunoblotting was performed to assess the chemo-resistance. Antiproliferative assays such as migration assay, clonogenic assay, Mitochondrial Membrane Potential (MMP) assay, dual staining assay, comet assay, Reactive Oxygen Species (ROS) assay, cell cycle analysis and immunoblotting assays were performed to witness the protein expression involved in chemoresistance and chemosensitization. Epithelial to mesenchymal transition was observed in nicotine induced chemoresistant cells. Gemcitabine sensitivity assay revealed that relative resistance was increased to 6.26 (p < 0.0001) and 6.45 (p < 0.0001) folds in resistant PANC-1 and MIA PaCa-2 compared to parental cells. Protein expression studies confirmed resistance markers like hENT1 and dCK were downregulated with subsequent increase in RRM1 expression in resistant cells. Embelin considerably decreased the cell viability with an IC50 value of 4.03 ± 0.08 µM in resistant PANC-1 and 2.11 ± 0.04 µM in resistant MIA PaCa-2. Cell cycle analysis showed Embelin treatment caused cell cycle arrest at S phase in resistant PANC-1 cells; in resistant MIA PaCa-2 cells there was an escalation in the Sub G1. Embelin upregulated Bax, γH2AX, p53, ERK1/2 and hENT1 expression with concomitant down regulation of Bcl-2 and RRM1. Bioactive molecule embelin, its combination with gemcitabine could provide new vistas to overcome chemo resistance in pancreatic cancer.

Tetrahydrobenzothiophene derivatives ameliorate Mia PaCa-2 cell progression and induces apoptosis via inhibiting EGFR2 tyrosine kinase signal.

A series of new thiophene analogues with acarbonitrile-basedmoiety were designed and synthesized via structural optimization. The conjugates were assessed for their in-vitro cytotoxic activity against a human pancreatic cancer cell line (Mia PaCa-2) and among them compound 5b showed IC50 value of 13.37 ± 2.37 µM. The compounds 5b (20 µM & 25 µM) and 7c (30 & 35 µM) also showed reduced clonogenicity, enhanced ROS and decreased mitochondrial membrane potential in Mia PaCa-2 cells. Treatment with these compounds also increased apoptotic population as evident with the double staining assay. Among the evaluated series, compounds 5b, 5g, 7c, and 9a attained a greater inhibitory potency than first generation's reversible EGFR inhibitor, Gefitinib. EGFR2 enzyme inhibitory studies revealed that 5b efficiently and arbitrarily suppressed the development of EGFR2 dependent cells and inhibited the enzymatic activity with an IC50 value of 0.68 µM; interestingly, the most effective molecule 5b with N-methyl piperazine substitution, has 1.29-fold greater potency than well-known EGFR inhibitor Gefitinib and increased Gefitinib's anti-growth impact with 2.04 folds greater against Mia PaCa-2. The in-vitro studies were validated with in-silico docking studies wherein compounds 5b and 7c exhibited binding energies of -8.2 and -7.4 Kcal/mol respectively. The present study reveals that tetrahydrobenzothiophene based analogues could be a promising lead for the evolution of potent chemo preventives over pancreatic cancer.

Potential role of embelin in the prevention of Freund's adjuvant induced inflammation and ROS.

Inflammation is a complex biological response involving immune cells to an infection creating injury to the normal tissues. The anti-inflammatory efficacy of embelin, a benzoquinone from the plant Embelia ribes, was screened for antioxidant and anti-inflammatory activity in carrageenan and Freund's adjuvant-induced inflammation models. Embelin exhibited significant dose-dependent antioxidant potential. In carrageenan-induced inflammation, embelin (20 mg/kg) showed an inhibition of oedema by 71.01 ± 0.12% and 81.91 ± 0.67% in Freund's adjuvant-treated chronic inflammation model and resulted in a noticeable increase in adrenal size and restoration of the weight of spleen. Embelin also demonstrated cytoprotective effects on HEK-293 cells under induced oxidative stress. In silico analysis, embelin demonstrated binding energy of - 7.7 kcal/Mol and - 7.0 kcal/Mol with COX1 and COX2 with two hydrogen bonds. These results further prove that embelin could be a promising anti-inflammatory agent and supports the traditional use of Embelia ribes for rheumatism.

Microwave assisted rapid synthesis and biological evaluation of stable copper nanoparticles using T. arjuna bark extract.

Terminalia arjuna (T. arjuna) bark extract is used to reduce Cu(2+)→Cu(0) under microwave irradiation. The formation of copper nanoparticles (CuNPs) is monitored by recording the UV-Vis absorption spectra for surface plasmon resonance (SPR) peak, ~535 nm. The intensity of SPR increased linearly with increasing temperature of the reaction mixture. The formation mechanism of CuNPs is supported by the observed marginal decrease in pH and an increase in solution potential (E) of the reaction mixture. X-ray diffraction (XRD) pattern of the CuNPs agrees with the reported data for Cu metal and the crystallite size is ~23 nm. Fourier transform infrared spectroscopy (FT-IR) and solid-state (13)C NMR shows the presence of plant residues on the CuNPs, i.e., in situ bio-capping is possible by this method. Thermo gravimetric (TG) analysis shows the thermal degradation of plant residue and the conversion of Cu to CuO. Field emission electron microscopic (FESEM) image shows uniform spherical particles obtained here. Elemental analysis by energy dispersive X-ray (EDX) analysis confirms the presence of Cu alone, as expected. The in vitro antimicrobial activity is found to be effective for CuNPs dried at RT when compared to CuNPs dried at 70 °C. In addition, CuNPs shows very good antioxidant property.

Synthesis and DNA cleavage studies of novel quinoline oxime esters.

New 2-chloro-3-formyl quinoline oxime esters were synthesized by the reaction of 2-chloro-3-formyl quinoline oximes with various benzoyl chlorides in the presence of triethyl amine and dichloromethane at 0°C. The DNA photo cleavage studies of some new oxime esters were investigated by neutral agarose gel electrophoresis at different concentrations (40µM and 80µM). Analysis of the cleavage products in agarose gel indicated that few of quinoline oxime esters (3d-i) converted into supercoiled pUC19 plasmid DNA to its nicked or linear form.

Analgesic, Antibacterial and Antiviral Activities of 2-(5-Alkyl-1,3,4-oxadiazol-2-yl)-3H-benzo[f]chromen-3-ones.

A novel series of 2-(5-alkyl-1,3,4-oxadiazol-2-yl)-3H-benzo[f]chromen-3-ones (4a-e) have been evaluated for analgesic, antibacterial and antiviral activities. Analgesic activity was carried out using acetic acid-induced writhing method in Swiss albino male mice. The antibacterial activity was performed against Gram-positive and Gram-negative clinical strains by agar well diffusion method. The in vitro antiviral activity was carried out against camelpox and buffalopox viruses. The analgesic activity exhibited by the compounds 4a, 4c and 4d were found to be more significant compared to the standard. The bacterial activity was determined by the inhibition of growth of the organism by the drugs at different concentrations. All the compounds showed significant activity when compared with the drug ciprofloxacin. The in vitro antiviral activity of the compound 4b tested against camelpox and buffalopox viruses revealed no activity when tested at concentrations of 250 µg. The compound 4b did not alter the titres of both the viruses and the titres remain, respectively, 10(6.5) TCID50 and 10(6.74) TCID50 per ml for camelpox vaccine virus and buffalopox vaccine virus. However, the compounds 4a-e showed significant analgesic and antibacterial activities.

Effect of ethanol extract of Rivea hypocrateriformis on the estrous cycle of the rat.

The ethanol extract of Rivea hypocrateriformis was administered orally at the dose levels of 200 and 400 mg/kg body weight to adult albino rats and resulted in an irregular estrous cycle with shortened estrus and metestrus, and with lengthened proestrus in non-dose dependent manner. Significant decreases in number of graffian follicles and corpora lutea and significant increases in number of atretic follicles in treated rats during experimental period indicated the antiovulatory effect of the extract. Increases in the weight of the uterus, its thickness and diameter indicated the uterotrophic effect of the extract. The significant increase in the level of cholesterol in the tissues of treated rats indicated the inhibition of steroidogenesis of cholesterol by ovarian endocrine tissues. Restoration of normal estrous cycles after withdrawal of treatment indicate the reversible effect of ethanol extract in rats.

Antiimplantation and pregnancy interruption efficacy of Rivea hypocrateriformis in the rat.

Petroleum ether, chloroform, ethanol and distilled water extracts of the aerial parts of the plant Rivea hypocrateriformis (Convolvulaceae) were tested for antiimplantation and pregnancy interruption properties in female albino rats. Among these, the ethanol extract was found to be most effective in causing significant antiimplantation and interruption of early pregnancy. The antifertility activity of ethanol extract was reversible on exogenous administration of hydroxy progesterone. However, the same ethanol extract was found to be ineffective in interruption of late pregnancy. Among the four extracts subjected to preliminary phytochemical screening, the active ethanol extract showed positive tests for alkaloids, glycosides, saponins, tannins and phenolic compounds.