Nutritional efficacy of a spermidine supplemented diet

A systematic exploration reveals the potential of spermidine for hypopigmentation treatment through the stabilization of melanogenesis-associated proteins

Spermidine (SPD), a polyamine naturally present in living organisms, is known to prolong the lifespan of animals. In this study, the role of SPD in melanogenesis was investigated, showing potential as a pigmenting agent. SPD treatment increased melanin production in melanocytes in a dose dependent manner. Computational analysis with RNA-sequencing data revealed the alteration of protein degradation by SPD treatment without changes in the expressions of melanogenesis-related genes. Indeed, SPD treatment significantly increased the stabilities of tyrosinase-related protein (TRP)-1 and -2 while inhibiting ubiquitination, which was confirmed by treatment of proteasome inhibitor MG132. Inhibition of protein synthesis by cycloheximide (CHX) showed that SPD treatment increased the resistance of TRP-1 and TRP-2 to protein degradation. To identify the proteins involved in SPD transportation in melanocytes, the expression of several solute carrier (SLC) membrane transporters was assessed and, among 27 transporter genes, SLC3A2, SLC7A1, SLC18B1, and SLC22A18 were highly expressed, implying they are putative SPD transporters in melanocytes. Furthermore, SLC7A1 and SLC22A18 were downregulated by SPD treatment, indicating their active involvement in polyamine homeostasis. Finally, we applied SPD to a human skin equivalent and observed elevated melanin production. Our results identify SPD as a potential natural product to alleviate hypopigmentation.

Health Implications of Dietary Amines: an overview of COST Action 922 (2001-2006)

The human diet contains significant amounts of amines and amine-related compounds that are present either naturally or as a result of food processing or storage. Some of these compounds are beneficial to health, while others are known to be hazardous or the dangers associated with them are poorly understood. Thus there is a need to bring together information from diverse scientific areas in order to evaluate the potential risks or benefits to human health of dietary amines.

Dietary polyamines and non-neoplastic growth and disease

This review presents the data that are now available concerning the effects of dietary polyamines at either postnatal or adult stages in non-neoplastic growth and disease. Polyamines provided by food have a potential role in growth and development of the digestive system in neonatal mammals (and fishes). In humans, this property could be of importance in preventing the appearance of food allergies. Dietary polyamines also seem necessary for the maintenance of normal growth and general properties of adult digestive tract. Their possible therapeutic effects have been investigated in gastric, intestinal, and, more recently, whole-body healing.

Clinical role of polyamine analysis: problem and promise

Polyamines are ubiquitous cell components for growth. They play an important role in cell proliferation, cell growth and synthesis of protein and nucleic acids. Cells that are stimulated to reproduce demonstrated early increases in biosynthetic enzymes involved in polyamine synthesis and subsequent elevations in polyamine levels. Extracellular fluid polyamine concentrations that reflect the intracellular events may be useful as rapid indicators of therapy in disorders which involve altered cell growth. More complex analytical approaches are required to isolate, identify and quantitate these polyamines. Most of the methods require an extraction procedure to remove interfering amino acid derivatives. Daily monitoring of plasma and urine polyamine levels in many pathological states may provide a non-invasive biochemical marker of the existing disease activity or response to therapy or to screen for drug efficacy. Automated high-performance liquid chromatography, with post or pre-column derivatization and fluorescence or electrochemical detection is frequently used for the simultaneous quantitation of picomolar quantities of polyamines. Recently, a new immuno-cytochemical model system incorporating an enzyme-linked immunosorbent assay for specific polyamines has been developed. The increasing momentum of basic science information in the polyamine discipline may lead clinicians to regard polyamines, their metabolites and antimetabolites as sources of effective treatment.

Polyamine oxidase and tissue transglutaminase activation in rat small intestine by polyamines

Polyamine degradation was studied in the small intestine from rats fed on a polyamine-supplemented diet. Lactalbumin diet was given to Hooded-Lister rats, with or without 5 mg rat(-1) day(-1) of putrescine or spermidine for 5 days. Polyamine oxidase activity increased with putrescine and spermidine in the diet, whereas spermidine/spermine N(1)-acetyltransferase and diamine oxidase activities were unchanged. We also studied the calcium-dependent and -independent tissue transglutaminase activities, since they can modulate intestinal polyamine levels. Both types of enzymes increased in the cytosolic fraction after putrescine (about 65%) or spermidine (80-100%). Our results indicate that exogenous polyamines stimulate intestinal polyamine oxidase and tissue transglutaminase activities, probably to prevent polyamine accumulation, when other pathways of polyamine catabolism (acetylation and terminal catabolism) are not activated.