Cytotoxic effects of chloroform and hydroalcoholic extracts of aerial parts of Cuscuta chinensis and Cuscuta epithymum on Hela, HT29 and MDA-MB-468 tumor cells.

Previous studies have indicated that some species of Cuscuta possess anticancer activity on various cell lines. Due to the lack of detailed researches on the cytotoxic effects of Cuscuta chinensis and Cuscuta epithymum, the aim of the present study was to evaluate cytotoxic effects of chloroform and hydroalcoholic extracts of these plants on the human breast carcinoma cell line (MDA-MB-468), human colorectal adenocarcinoma cell line (HT29) and human uterine cervical carcinoma (Hela). Using maceration method, different extracts of aerial parts of C. chinensis and C. epithymum were prepared. Extraction was performed using chloroform and ethanol/water (70/30). Total phenolic contents of the extracts were determined according to the Folin-Ciocalteu method. Using MTT assay, the cytotoxic activity of the extracts against HT29, Hela and MDA-MB-468 tumor cells was evaluated. Extracts were considered cytotoxic when more than 50% reduction on cell survival was observed. The poly-phenolic content of the hydroalcoholic and chloroform extracts of C. chinensis and C. epithymum were 56.08 ± 4.11, 21.49 ± 2.00, 10.64 ± 0.86 and 4.81 ± 0.38, respectively. Our findings showed that the chloroform extracts of C. chinensis and C. epithyum significantly reduced the viability of Hela, HT-29 and MDA-MB-468 cells. Also, hydroalcoholic extracts of C. chinensis significantly decreased the viability of HT29, Hela and MDA-MB-468 cells. However, in the case of hydroalcoholic extracts of C. epithymum only significant decrease in the viability of MDA-MB-468 cells was observed (IC50 = 340 µg/ml). From these findings it can be concluded that C. chinensis and C. epithymum are good candidates for further study to find new possible cytotoxic agents.

Impact of the ultrarapid CYP2C19*17 allele on serum concentration of escitalopram in psychiatric patients.

Recently, a novel allelic variant of cytochrome P450 2C19 encoding ultrarapid enzyme activity was described (denoted CYP2C19*17). The objective of this study was to evaluate the impact of CYP2C19*17 on serum concentration of escitalopram in psychiatric patients. One hundred and sixty-six patients treated with escitalopram were divided into the following subgroups according to CYP2C19 genotype: CYP2C19*17/*17 (n=7), CYP2C19*1/*17 (n=43), CYP2C19*1/*1 (n=60), CYP2C19*17/def (n=16), CYP2C19*1/def (n=34), and CYP2C19def/def (n=6) (def=defective allele, i.e., CYP2C19*2 or *3). Dose-adjusted serum concentrations of escitalopram were compared using the CYP2C19*1/*1 subgroup as reference. Geometric mean of the escitalopram serum concentration was 42% lower in patients homozygous for CYP2C19*17 (P<0.01) and 5.7-fold higher in subjects homozygous for defective CYP2C19 alleles (P<0.001). Of the heterozygous subgroups, only CYP2C19*1/def was significantly different from CYP2C19*1/*1 (P<0.001). In conclusion, a homozygous CYP2C19*17 genotype is associated with lower serum concentration of escitalopram, which might imply increased risk of therapeutic failure.

The Drosophila ribosomal protein L14-encoding gene, identified by a novel Minute mutation in a dense cluster of previously undescribed genes in cytogenetic region 66D.

The Minute phenotype results from mutations at > 50 loci scattered throughout the genome of Drosophila. Common traits of the Minute phenotype are short and thin bristles, slow development, and recessive lethality. Here, we report a novel P-element induced Minute mutation, P¿lacW¿ M(3)66D1, that maps to region 66D on chromosome 3L. Flies heterozygous for P¿lacW¿ M(3)66D1 have a strong Minute phenotype. Molecular characterisation of the chromosomal region revealed three previously undescribed Drosophila genes clustered within a 5-kb genomic fragment. Two of the genes have significant sequence homology to genes for the mammalian ribosomal proteins L14 and RD, respectively, and share a joint 240-bp promoter region harbouring the P-element insert. Quantitative Northern blot analyses showed the mutation to affect RPL14 mRNA levels only. Interestingly, the reduction in abundance of RPL14 mRNA is not constitutive, indicating that the promoter function abolished by the inserted P-element is utilised with different efficiencies in different developmental situations. Remobilisation of the P element produced wild-type flies with normal levels of RPL14 mRNA, demonstrating that the mutant phenotype is caused by the insertion. P¿lacW¿ M(3)66D1 joins a growing list of Minute mutations associated with ribosomal protein-haploinsufficiency.