or quinolinic acid (or both). The modifying gene has no demonstrable effect on the utilization of exogenously supplied nicotinamide (K. Nakamura and C. S. Gowans, Genetics 51:931, 1965). Two observations strongly indicate that the modifying gene does not operate through a modification of the pathway of synthesis of niacin. First, the nicotinamide auxotrophs carrying the modifying gene grow norm...

1. Chronic administration of glucose or nicotinamide in drinking water inhibits the activity of rat liver tryptophan pyrrolase, and subsequent withdrawal causes an enhancement. The enzyme activity is also inhibited by administration in drinking water of sucrose, but not fructose, which is capable of preventing the glucose effect. 2. The inhibition by glucose or nictinamide is not due to a defec...

Inhibition of Trypanosoma brucei and Leishmania spp. sirtuins has shown promising antiparasitic activity, indicating that these enzymes may be used as targets for drug discovery against trypanosomatid infections. In the present work we carried out a virtual screening focused on the C pocket of Sir2 from Trypanosoma cruzi. Using this approach, the best ligand found was nicotinamide. In vitro tes...

Insulin dependent diabetes mellitus (IDDM) results from irreversible loss of beta cells (beta-cells) of the pancreas. A Streptozotocin (STZ)-induced diabetes in animal model mimics, in some aspects, recent onset IDDM. This study was conducted to investigate the effect of nicotinamide on experimentally-induced IDDM. Thirty Spraque Dawley rats were divided into 3 groups; a control group, a diabet...

Application o f [6 14C]or [7-14C]nicotinic acid to parsley cell suspension cultures led to the accumulation of labelled nicotinamide m ononucleotide, nicotinamide adenine dinucleotide, nicotinamide N-riboside, nicotinamide and nicotinic acid, indicating the operation of the pyridine nucleotide cycle in these cells. A s main conjugates, nicotinic acid N-glucoside and nicotinic acid glucose ester...

Previous studies from our laboratory indicated that the initial step in the biosynthesis of nicotinamide adenine dinucleotide from nicotinamide in mammalian liver involves the enzymatic deamidation of nicotinamide to nicotinic acid (1, 2). The nicotinic acid is then converted to NAD via the pathway described by Preiss and Handler, involving the intermediate formation of nicotinic acid mononucle...

fenugreek (trigonella foenum-graecum l.) has a long and respected history of medicinal uses in middle east and persian medicine. the hypocholesterolaemic and hypoglycaemic effects of fenugreek were attributed to its major steroidal sapogenin, diosgenin and its major alkaloid, trigonelline. the knowledge of diosgenin and trigonelline biosynthesis is derived from studies of cholesterol and nicoti...

BACKGROUND Nicotinamide adenine dinucleotide (NAD(+)) and its phosphorylated form (NADP(+)) are key molecules in ubiquitous bioenergetic and cellular signaling pathways, regulating cellular metabolism and homeostasis. Thus, supplementation with NAD(+) and NADP(+) precursors emerged as a promising strategy to gain many and multifaceted health benefits. In this proof-of-concept study, we sought t...

We have continued our investigation into the mechanism by which nicotinamide can enhance radiation damage in tumors, using a C3H mouse mammary carcinoma grown in CDF1 mice. Biochemical analysis of tumor extracts showed that nicotinamide (1000 mg/kg; i.p.) increased the ATP/Pi and ATP/ADP + AMP ratios. This change in metabolic activity was consistent with nicotinamide increasing tumor oxygenatio...