Anticlastogenic effects of centchroman and its enantiomers in Swiss albino mice. I. Acute study and their comparison with tamoxifen

Comparative differential cytotoxicity of clinically used SERMs in human cancer lines of different origin and its predictive molecular docking studies of key target genes involved in cancer progression and treatment responses

SERMS like Tamoxifene, 5-hydroxy tamoxifene, raloxifene and endoxifene has been used for the treatment of hormonal imbalances and dependent cancers owing to their action via Estrogen receptors as in the treatment of estrogen sensitive breast cancers. Due to the adverse side effects, modifications and development of the existing or newer SERMS has always been of immense interest. Ormeloxifene, a SERM molecule manufactured by HLL Lifecare Ltd, India as birth control under the trade names Saheli, Novex, and Novex-DS which is also investigated against mastalgia, fibro-adenoma and abnormal uterine bleeding. Anti-cancer effects have been reported in estrogen dependent and independent cancers which shows its wide scope to be implemented in cancer therapy. Current investigation is a comprehensive effort to find the cytotoxic potential of Ormeloxifene in comparison with clinically used four SERMS in twenty six cancer cell lines of different origin using Adriamycin as positive control. Also the computational studies pertaining to selected target/ligand with respect to tumor progression, development, treatment responses and apoptosis. The studies proved effective cytotoxicity of Ormeloxifene on cancer cell lines with lower TGI, GI50 and LC50 values which are significantly comparable. Also the in silico studies proved that the docking score of the compound suggests the interaction of the compound which could tightly regulate key target genes controlling cancer like ER, EGFR kinase, EGFR-cSRC, HDAC-2, PARP-1 and BRAF. This study brings out the superior efficacy of Ormeloxifene compared to other SERMS with proven safety profile to be repositioned as an anti-cancer drug to treat diverse cancer types.

Regio- and diastereoselective synthesis of trans-3,4-diaryldihydrocoumarins via metal-free [4+2] annulation of ynamides with o-hydroxybenzyl alcohols

An efficient regio- and diastereoselective method for the construction of valuable trans-3,4-diaryldihydrocoumarins via metal-free [4+2] annulation of ynamides with o-hydroxybenzyl alcohols has been developed. Ynamides are first treated as 2-π partners to react with o-hydroxybenzyl alcohols via traceless sulfonamide directing groups, affording trans-3,4-diaryldihydrocoumarins in good yields with high regio- and diastereoselectivities. This metal-free methodology is also characterized by a wide substrate scope, good functional group tolerance, and efficiency on a gram scale.

2-D gel electrophoresis-based proteomic analysis reveals that ormeloxifen induces G0-G1 growth arrest and ERK-mediated apoptosis in chronic myeloid leukemia cells K562

Ormeloxifen is a nonsteroidal selective estrogen receptor modulator (SERM) and has been shown to possess anticancer activities in breast and uterine cancer. Here, we show that ormeloxifen induces apoptosis in dose-dependent manner in a variety of leukemia cells, more strikingly in K562. 2-DE-gel electrophoresis of K562 cells induced with ormeloxifen showed that 57 and 30% of proteins belong to apoptosis and cell-cycle pathways, respectively. Our data demonstrate that ormeloxifen-induced apoptosis in K562 cells involves activation of extracellular signal-regulated kinases (ERKs) and subsequent cytochrome c release, leading to mitochondria-mediated caspase-3 activation. Ormeloxifen-induced apoptosis via ERK activation was drastically inhibited by prior treatment of K562 cells with ERK inhibitor PD98059. Ormeloxifen also inhibits proliferation of K562 cells by blocking them in G0-G1 phase by inhibiting c-myc promoter via ormeloxifen-induced MBP-1 (c-myc promoter-binding protein) and upregulation of p21 expression. We further show that ormeloxifen-induced apoptosis in K562 is translatable to mononuclear cells isolated from chronic myeloid leukemia (CML) patients. Thus, ormeloxifen induces apoptosis in K562 cells via phosphorylation of ERK and arrests them in G0-G1 phase by reciprocal regulation of p21 and c-myc. Therefore, inclusion of ormeloxifen in the therapy of chronic myeloid leukemia can be of potential utility.

Anticlastogenic effects of black tea polyphenols theaflavins and thearubigins in human lymphocytes in vitro

Black tea accounts for nearly 80% of total World tea production. It contains dimeric flavanols and polymeric polyphenols known as theaflavins (TF) and thearubigins (TR). TR is exclusively present in black tea. On the basis of our previous potent antimutagenic and anticlastogenic effects of TF and TR in vitro in bacterial system and in vivo in mouse bone marrow cells, we have decided to extend our study in human cells in vitro. This study investigated the anticlastogenic effects of black tea polyphenols TF and TR as measured by chromosomal aberrations (CA) and micronuclei formation (MN) against two known mutagens/carcinogens i.e. benzo[a]pyerne (B[a]P) and aflatoxin B1(AFB1) with S9 activation. A significant decrease in both CA and MN were observed in the human lymphocyte cultures treated with either TF or TR pretreated with either B[a]P or AFB1 (250, 500, 1000 microg/ml) when compared with B[a]P or AFB1 treated cultures alone. TF shows more protective effects than TR in this in vitro system. These results indicate that both TF and TR have significant anticlastogenic effects in vitro in human lymphocytes.

Comparative antimutagenic effects of D- and L-centchroman and their comparison with tamoxifen in Salmonella assay

Centchroman (CC)--a contraceptive and a candidate drug for breast cancer has been developed by the Central Drug Research Institute. It has been successfully marketed as a contraceptive for last several years. CC has also been reported to exhibit partial to complete remission of lesions in 40.5% breast cancer patients. Recently, we have reported the antimutagenic effects of CC in Ames Salmonella assay and in vivo and in vitro mammalian cells in multiple mutational assay. The potent antimutagenic activity of CC and its anti-breast cancer activity prompted us to evaluate the antimutagenic effects of its enantiomers, i.e., D-centchroman (DC) and L-centchroman (LC) in the Ames Salmonella strains TA97a, TA98, TA100 and TA102 against known bacterial mutagens. Attempts have also been made to compare the results of antimutagenicity assays of CC and its enantiomers with the known breast cancer drug tamoxifen (TM). The main objective was to identify the best suitable form of CC having antimutagenic effects with anticancer profile similar to TM, would replace the latter for toxicity reasons. When mutagenicity assays were carried out with these compounds as expected like CC, none of these enantiomers or TM showed any mutagenic effects in these Salmonella strains. In the antimutagenicity assay a significantly reduced number of bacterial histidine revertant colonies were observed when positive compounds were co-incubated with certain concentrations of LC compared with bacterial plates treated with respective positive compound. This was observed in some concentrations in all the four strains in both plate incorporation and preincubation tests. The protective effects of LC in preincubation tests were slightly more than in plate incorporation tests. Both the DC and TM showed protective effects only in certain concentrations in some strains in either plate or preincubation tests. Thus the above results indicate that LC showed more protective effects in Salmonella strains TA97a, TA98, TA100 and TA102 than either DC or TM.