Polymorphic Signature of the Anti-inflammatory Activity of 2,2′- {[1,2-Phenylenebis(methylene)]bis(sulfanediyl)}bis(4,6- dimethylnicotinonitrile)

Weak noncovalent interactions are the basic forces in crystal engineering. Polymorphism in flexible molecules is very common, leading to the development of the crystals of same organic compounds with different medicinal and material properties. Crystallization of 2,2′- {[1,2-phenylenebis(methylene)]bis(sulfanediyl)}bis(4,6-dimethylnicotinonitrile) by evaporation at room temperature from ethyl acetate and hexane and from methanol and ethyl acetate gave stable polymorphs 4a and 4b, respectively, while in acetic acid, it gave metastable polymorph 4c. The polymorphic behavior of the compound has been visualized through singlecrystal X-ray and Hirshfeld analysis. These polymorphs are tested for anti-inflammatory activity via the complete Freund’s adjuvant-induced rat paw model, and compounds have exhibited moderate activities. Studies of docking in the catalytic site of cyclooxygenase-2 were used to identify potential anti-inflammatory lead compounds. These results suggest that the supramolecular aggregate structure, which is formed in solution, influences the solid state structure and the biological activity obtained upon crystallization

Comparison of tRNA conformation during different phases of reproduction

The present study is a comparison of tRNA conformation from ovary of Heteropneustes fossilis in its active phase of reproduction (when it is highly engaged in protein synthesis i.e. previtellogenic phase) with inactive phase (when tRNA is mainly stored in mature ovary i.e. spawning phase). Transfer RNA of active phase is shown to be compact, flexible and susceptible towards nuclease. Compact tRNA structure is evidenced by higher hyperchromicity and presence of relatively less Gm modifications thereby allowing adequate hydrogen bonding between D loop and T loop. Higher sensitivity of tRNA towards Mg++ reflects its higher flexibility towards internal environment. This structure of tRNA may be required for active protein synthesis. On the other hand tRNA of inactive phase is shown to be relaxed but resistant towards nuclease which may be favoured for storage in mature ova of a teleost as maternal carry over

Long term effect of curcumin in regulation of glycolytic pathway and angiogenesis via modulation of stress activated genes in prevention of cancer.

Oxidative stress, an important factor in modulation of glycolytic pathway and induction of stress activated genes, is further augmented due to reduced antioxidant defense system, which promotes cancer progression via inducing angiogenesis. Curcumin, a naturally occurring chemopreventive phytochemical, is reported to inhibit carcinogenesis in various experimental animal models. However, the underlying mechanism involved in anticarcinogenic action of curcumin due to its long term effect is still to be reported because of its rapid metabolism, although metabolites are accumulated in tissues and remain for a longer time. Therefore, the long term effect of curcumin needs thorough investigation. The present study aimed to analyze the anticarcinogenic action of curcumin in liver, even after withdrawal of treatment in Dalton's lymphoma bearing mice. Oxidative stress observed during lymphoma progression reduced antioxidant enzyme activities, and induced angiogenesis as well as activation of early stress activated genes and glycolytic pathway. Curcumin treatment resulted in activation of antioxidant enzyme super oxide dismutase and down regulation of ROS level as well as activity of ROS producing enzyme NADPH:oxidase, expression of stress activated genes HIF-1α, cMyc and LDH activity towards normal level. Further, it lead to significant inhibition of angiogenesis, observed via MMPs activity, PKCα and VEGF level, as well as by matrigel plug assay. Thus findings of this study conclude that the long term effect of curcumin shows anticarcinogenic potential via induction of antioxidant defense system and inhibition of angiogenesis via down regulation of stress activated genes and glycolytic pathway in liver of lymphoma bearing mice

PI-103 and Quercetin Attenuate PI3K-AKT Signaling Pathway in T- Cell Lymphoma Exposed to Hydrogen Peroxide.

Phosphatidylinositol 3 kinase-protein kinase B (PI3K-AKT) pathway has been considered as major drug target site due to its frequent activation in cancer. AKT regulates the activity of various targets to promote tumorigenesis and metastasis. Accumulation of reactive oxygen species (ROS) has been linked to oxidative stress and regulation of signaling pathways for metabolic adaptation of tumor microenvironment. Hydrogen peroxide (H2O2) in this context is used as ROS source for oxidative stress preconditioning. Antioxidants are commonly considered to be beneficial to reduce detrimental effects of ROS and are recommended as dietary supplements. Quercetin, a ubiquitous bioactive flavonoid is a dietary component which has attracted much of interest due to its potential health-promoting effects. Present study is aimed to analyze PI3K-AKT signaling pathway in H2O2 exposed Dalton's lymphoma ascite (DLA) cells. Further, regulation of PI3K-AKT pathway by quercetin as well as PI-103, an inhibitor of PI3K was analyzed. Exposure of H2O2 (1mM H2O2 for 30min) to DLA cells caused ROS accumulation and resulted in increased phosphorylation of PI3K and downstream proteins PDK1 and AKT (Ser-473 and Thr-308), cell survival factors BAD and ERK1/2, as well as TNFR1. However, level of tumor suppressor PTEN was declined. Both PI-103 & quercetin suppressed the enhanced level of ROS and significantly down-regulated phosphorylation of AKT, PDK1, BAD and level of TNFR1 as well as increased the level of PTEN in H2O2 induced lymphoma cells. The overall result suggests that quercetin and PI3K inhibitor PI-103 attenuate PI3K-AKT pathway in a similar mechanism

Förder- und Sortiertechniken

<p>Effect of curcumin on mRNA expression and protease activity of MMP 9 and 2 in liver of lymphoma bearing mice (A) RT-PCR of MMP9, MMP2 and β-actin genes, (B) Densitometric scanning of MMP9 and MMP2 genes after normalization with β-actin, (C) Gelatin Zymography showing protease activity of MMP9 and MMP2, (D) Densitometric scanning of the activity band of MMP9 and MMP2. Livers of all six animals of each group were pooled separately and used for extraction of total RNA and proteins at non denaturing condition. Data represent mean ± S.E.M. #p<0.05 and ##<0.01 compared to N group, *p<0.05 and **p<0.01 compared to DL+DMSO group respectively. Cur is curcumin, M is 100 bp marker and bw is body weight. N, DL, DL+DMSO, DLT50, DLT100 and DLT150 represents normal, Dalton's lymphoma bearing, Dalton's lymphoma bearing mice treated with DMSO and Dalton's lymphoma bearing mice treated with 50, 100 and 150 mg curcumin/kg body weight dissolved in DMSO respectively.</p

Long Term Effect of Curcumin in Restoration of Tumour Suppressor p53 and Phase-II Antioxidant Enzymes via Activation of Nrf2 Signalling and Modulation of Inflammation in Prevention of Cancer

<div><p>Inhibition of carcinogenesis may be a consequence of attenuation of oxidative stress via activation of antioxidant defence system, restoration and stabilization of tumour suppressor proteins along with modulation of inflammatory mediators. Previously we have delineated significant role of curcumin during its long term effect in regulation of glycolytic pathway and angiogenesis, which in turn results in prevention of cancer via modulation of stress activated genes. Present study was designed to investigate long term effect of curcumin in regulation of Nrf2 mediated phase-II antioxidant enzymes, tumour suppressor p53 and inflammation under oxidative tumour microenvironment in liver of T-cell lymphoma bearing mice. Inhibition of Nrf2 signalling observed during lymphoma progression, resulted in down regulation of phase II antioxidant enzymes, p53 as well as activation of inflammatory signals. Curcumin potentiated significant increase in Nrf2 activation. It restored activity of phase-II antioxidant enzymes like GST, GR, NQO1, and tumour suppressor p53 level. In addition, curcumin modulated inflammation via upregulation of TGF-β and reciprocal regulation of iNOS and COX2. The study suggests that during long term effect, curcumin leads to prevention of cancer by inducing phase-II antioxidant enzymes via activation of Nrf2 signalling, restoration of tumour suppressor p53 and modulation of inflammatory mediators like iNOS and COX2 in liver of lymphoma bearing mice.</p></div

Nrf2 activation (NFE2 binding).

<p>Effect of curcumin on DNA binding activity of Nrf2 with NFE2 consensus sequences. (A) Titration with unlabelled probe as specific competitor. (B) Titration with poly-dI/dC as non-specific competitor. (C) Autoradiogram showing Nrf2-NFE2 complex (D) Densitometric scanning of Nrf2-NFE2 complex. Liver of all six animals of each group was pooled separately and used for extraction of nuclear proteins. Data represent mean ± S.E.M. # and * denotes significant difference compared with N and DL+DMSO group respectively. Cur is curcumin and bw is body weight. N, DL, DL+DMSO, DLT50, DLT100 and DLT150 represents normal, Dalton’s lymphoma bearing, Dalton’s lymphoma bearing mice treated with DMSO and Dalton’s lymphoma bearing mice treated with 50, 100 and 150 mg curcumin/kg body weight dissolved in DMSO respectively.</p

Expression of Nrf2.

<p>Effect of curcumin on mRNA expression of Nrf2. (A) RT-PCR of Nrf2 and β-actin. (B) Densitometric scanning of Nrf2 after normalization with β-actin. Liver of all six animals of each group was pooled separately and used for extraction of total RNA. Data represent mean ± S.E.M. # and * denotes significant difference compared with N and DL+DMSO group respectively. Cur is curcumin and bw is body weight. N, DL, DL+DMSO, DLT50, DLT100 and DLT150 represents normal, Dalton’s lymphoma bearing, Dalton’s lymphoma bearing mice treated with DMSO and Dalton’s lymphoma bearing mice treated with 50, 100 and 150 mg curcumin/kg body weight dissolved in DMSO respectively.</p

Expression of TGF-β1.

<p>Effect of curcumin on mRNA expression of TGF-β1 (A) RT-PCR of TGF-β1 and β-actin (B) Densitometric scanning of TGF-β1 after normalization with β-actin. Liver of all six animals of each group was pooled separately and used for extraction of total RNA. Data represent mean ± S.E.M. # and * denotes significant difference compared with N and DL+DMSO group respectively. Cur is curcumin and bw is body weight. N, DL, DL+DMSO, DLT50, DLT100 and DLT150 represents normal, Dalton’s lymphoma bearing, Dalton’s lymphoma bearing mice treated with DMSO and Dalton’s lymphoma bearing mice treated with 50, 100 and 150 mg curcumin/kg body weight dissolved in DMSO respectively.</p