Medicinal Chemistry - Volume 7, Issue 6, 2011

The potential protective effect of (±)-8-methoxy-1,3,4,4a,5,9b-hexahydro-pyrido[4,3-b]indole-2-carboxylic acid ethyl ester (II) was assessed against hydrogen peroxide (H2O2)-cytotoxicity in rat pancreatic INS-1E β cells and compared with the effect of the related pyridoindole, stobadine (I), a promising indole-type reference antioxidant. Only pre-treatment with the compound (II) led to a significant preservation of the metabolic and secretory functions of the cells exposed to H2O2. The caspase-9 and -3 activities, as well as the early apoptotic changes of plasma membrane, were suppressed in the cells pre-incubated with both of compounds tested. However, only pyridoindole (II) inhibited profoundly the time-delayed apoptotic changes, These results suggest that pyridoindole (II) characterized by enhanced intrinsic antioxidant efficiency, may protect ?? cells against cytotoxic effects of H2O2, involved in the development of both type 1 and type 2 diabetes.

Nicotinamide adenine dinucleotide (NAD+) is synthesized by the action of nicotinamide mononucleotide adenylyltransferase (NMNAT) from NMN and ATP. The mouse homolog of NMNAT-2 (mmNMNAT-2) was cloned, expressed, and subsequently identified using MALDI-TOF in conjunction with the ProFound database. Circular dichroism analyses of recombinant mmNMNAT-2 showed α helical and β sheet secondary structures, consistent with the known structure of the human isoform. Competition experiments using mouse pancreatic tissue lysates with recombinant mmNMNAT-2 demonstrated that the activity of the expressed protein was similar to the human isoform. Immunohistochemistry of mouse embryonic tissues with hNMNAT-2 also showed a tissue- and cellular-specific expression of this isoform. Therefore, our studies demonstrate for the first time the clear biological evidence for the existence of a mouse isoform of hNMNAT-2. These studies may help in future investigations aimed at understanding the regulation of this gene and its pathway, and in turn, will spur the development of novel therapies for diseases such as cancer and diabetes since mice are the most frequently used experimental system for in vivo studies.

A series of simple (6-substitutedbenzothiazol-2-yl)acrylamides was synthesized and evaluated for cytotoxicity and antimicrobial effects. All six compounds displayed very significant cytotoxicity against four cancer cell lines tested including A549 (a human lung cancer cell line), Hela (a human ovarian cancer cell line), MCF7 (a human breast cancer cell line), and even MCF7-ADR (adriamycin-resistant human breast cancer cell line), with IC50 values in microgram/ml range and as low as 0.66 μg/ml. The synthesized compounds also exhibited some antifungal effects against Apergillus niger.