Telomerase Inhibitors and Activators: Pharmaceutical Importance

Telomeres are specialized functional complexes that protect the ends of eukaryotic chromosomes. The telomeric DNA sequences are tandem repeats of a short hexameric sequence unit. The inability to DNA polymerase to replicate the end of the chromosome during lagging strand synthesis results in the loss of telomeric repeats when cell divides. Telomere shortening provides a barrier to cancer progression and the majority of the cancer cells depend on the activation of telomerase to gain proliferative immortality. Thus, telomerase is a molecular target for diseases since its discovery. Telomerase inhibition enables more specific ground for cancer therapy because the telomerase is not detected in most normal tissues. Some of the synthetic and natural telomerase inhibitors were tried on various cancer cells and there was a decrease in the number of cancer cells. But on the other hand, telomere shortening correlates with cellular aging. Some evidence suggests that the progressive loss of telomeric repeats of chromosomes may function as a molecular clock that triggers senescence. Telomerase-related gene mutations also result in some diseases. Because of this, telomerase activators are important for antiaging and telomerase-dependent disease treatments. This chapter summarizes the pharmaceutical importance of telomeres, telomerase structure, telomerase activators, and inhibitors

The effects of metformın, acetylsalıcylıc acıd and ıbuprofen on telomerase enzyme actıvıty: ınhıbıtory effect of ıbuprofen

Telomerase enzyme is necessary for the elongation of telomeres while telomerase being critical for aging and cancer. Metformin, ibuprofen, and acetylsalicylic acid used in this research are drugs that millions of people already use and that many are likely to use in future. In this study, the effects of these drugs on telomerase activity of Mus musculus swiss albino mice in liver tissue were investigated and the telomerase activity was measured with a PCR-ELISA based kit. In the study a possible connection between telomerase enzyme activity and activities of antioxidant enzymes was also investigated by determining the activity of superoxide dismutase (SOD) and catalase enzymes. The data obtained show that metformin slightly decreased telomerase enzyme activity in low dose application; however, this change was not statistically significant. In ibuprofen application, there was a significant inhibitory effect when high doses were used; whereas, there was a slight inhibitory effect at low doses. In acetylsalicylic acid application, a slight activator effect was detected; it was not statistically significant, though. Metformin was observed to increase catalase and SOD activities in general while low and high doses of acetyl salicylic acid showed different effects. In addition, ibuprofen caused a statistically significant increase in liver SOD values. It is important to note that this study demonstrated a significant inhibitory effect of ibuprofen on telomerase enzyme activity in animal models

Determination of Aflatoxin M1 Levels and Antibiotic Residues in the Traditional Turkish Desserts and Ice Creams Consumed in Burdur City Center

WOS: 000281374200009Aflatoxins display an insufficiently recognized risk to human health. Aflatoxins M1 and M2 are oxidative metabolites of aflatoxins B1 and B2 in milk. They can be found in a variety of food items and are not destroyed by normal industrial processing or cooking. Also, foods from animals may contain residues of antibacterial drugs. In this study, totally 47 traditional milky dessert and ice cream samples including sutlac, gullac, muhallebi and ice cream were investigated for aflatoxin M1 by ELISA and for antibacterial drugs by bacterial growth inhibition methods. Aflatoxin values of the 8 samples exceeded 50 ng kg(-1) and among them only one sample exceeded 250 ng kg(-1). Thirty-one of the 47 milky dessert samples were positive. According to the results, antibiotic residues were detected in 32 out of 47 samples of milky desserts (68.1%). The milky desserts including aflatoxin M1 and/or antimicrobial drug residues are potential risk for public health. Prevention of the contamination of aflatoxin B1 and B2 in the animal food may prevent formation of aflatoxin M1 in animal products. Also, the farmers should be educated for the prevention of antibiotic residues in milk

Two New Species of Chondrostoma Agassiz, 1832 (Teleostei: Cyprinidae) from the Ceyhan, Seyhan and Goksu Rivers in the East Mediterranean Region of Turkey

GUCLU, Salim Serkan/0000-0002-9256-449XWOS: 000403575500015Chondrostoma toros sp.n. was described from the Goksu River. It was distinguished by a slightly arched lower jaw with a well-developed keratinized edge; a slightly developed keel in front of the dorsal-fm origin; lateral line with 56-64+1-3 scales; and 25-30 gill-rakers on outer side of first gill arch. Chondrostoma ceyhanensis sp.n. was described from Ceyhan, Seyhan and Berdan rivers. It was distinguished by its arched lower jaw with a slightly developed keratinized edge; a slightly developed keel between pelvic-fin and anus; lateral line with 59-66+1-3 scales; and 24-29 short gill-rakers on outer side of first gill arch.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [KBAG-111T900]This study was supported by a grant from Scientific and Technological Research Council of Turkey (TUBITAK) (Project No: KBAG-111T900

A new Chondrostoma species from the Buyuk Menderes River Basin, Turkey (Teleostei: Cyprinidae)

GUCLU, Salim Serkan/0000-0002-9256-449XWOS: 000445800000004In a study of the fishes of the Buyuk Menderes River Basin, Aegean region of Turkey, two populations of Chondrostoma were found which showed clearly distinctive characters: the population from the Upper B. Menderes (Ikl Lake) was attributed to C. meandrense Elvira, 1987, while the population from the Cine Stream in the Lower B. Menderes River basin proved to be a hitherto undescribed species: Chondrostoma turnai sp. n. Altogether 24 metric and 7 meristic parameters were compared. the new species is distinguished from C. meandrense and all other cogeners by a combination of the number of lateral line scales, the number of scale rows between the lateral line and the dorsal-fin origin, the number of scale rows of the lateral line and pelvic-fin origin, and the number of gill rakers on the first gill arch.http://www.zoobank.org/urn:lsid:zoobank.org:pub:811C213D-BEDD-4C8C-AE57-BFFA7964781AScientific and Technological Research Council of Turkey (TuBTAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [KBAG-111T900]This study was supported by a grant from the Scientific and Technological Research Council of Turkey (TuBTAK) (Project No: KBAG-111T900)