EFFECT OF TRYPTOPHAN SUPPLEMENTATION ON GROWTH PERFORMANCE OF MEAT TYPE BIRDS: A REVIEW

The requirement of animal protein is increasing with the population growth of the world. To fulfil this requirement, poultry meat is the cheapest and major source of animal protein. However, growth of broiler birds is being maximized by supplementing various nutrients from both artificial and natural source. One of the major nutrient for optimizing broiler growth performance are amino acids. Amino acids play a major role in meat type bird’s growth as they are the building blocks of protein synthesis and regulate different metabolic pathways. These metabolic pathways increases the digestion and absorption of nutrients. The purpose of this review is to insight the effect of tryptophan on production parameters and metabolic pathways involved in the synthesis of serotonin. On the basis of this review, we can conclude that tryptophan level of 0.20% during the starter phase and 0.15% during the finisher phase is mandatory to maintain optimum growth performance. However, tryptophan level of 0.20% is sole precursor for the synthesis of serotonin that is a neuromediator. Serotonin is involved in the dietary choice of broiler bird, improving gastrointestinal motility and intestinal secretion. Therefore, it is concluded that optimum level of tryptophan should be maintained in diet either by natural or synthetic source to optimize the growth performance and metabolic activities.

Fucose Ameliorates Tryptophan Metabolism and Behavioral Abnormalities in a Mouse Model of Chronic Colitis

Growing evidence suggests that intestinal mucosa homeostasis impacts immunity, metabolism, the Central Nervous System (CNS), and behavior. Here, we investigated the effect of the monosaccharide fucose on inflammation, metabolism, intestinal microbiota, and social behavior in the Dextran Sulfate Sodium (DSS)-induced chronic colitis mouse model. Our data show that chronic colitis is accompanied by the decrease of the serum tryptophan level and the depletion of the intestinal microbiota, specifically tryptophan-producing E. coli and Bifidobacterium. These changes are associated with defects in the male mouse social behavior such as a lack of preference towards female bedding in an odor preference test. The addition of fucose to the test animals’ diet altered the bacterial community, increased the abundance of tryptophan-producing E. coli, normalized blood tryptophan levels, and ameliorated social behavior deficits. At the same time, we observed no ameliorating effect of fucose on colon morphology and colitis. Our results suggest a possible mechanism by which intestinal inflammation affects social behavior in male mice. We propose fucose as a promising prebiotic, since it creates a favorable environment for the beneficial bacteria that promote normalization of serum tryptophan level and amelioration of the behavioral abnormalities in the odor preference test.

Eel’s Head Powder Reduces Mild-Moderate Depression in Geriatric Individual: Result from Randomized Controlled Trial Study

Depression is one of the major problems, and the prevalence is higher among the elderly. The underlying mechanism of depression among this set of the population is multifactorial, and one of the most important factors in the pathophysiology of depression is the level of brain serotonin. Protein deficiency is linked to tryptophan deficiency that is known to be the essential material for the synthesis of serotonin. This randomized controlled trial looked for the effectiveness of eel’s head powder administration on plasma tryptophan level and geriatric depression scale (GDS) scores among the elderly population who suffered from depression. The subjects were divided into three intervention groups, including groups that were given 2-week course of 5 mg/kg BW eel’s head powder, 10 mg/kg BW eel’s head powder, and placebo, respectively. There was a significant difference in plasma tryptophan level and geriatric depression scale between the 10 mg/kg BW group and 5 mg/kg BW group. There was also a significant difference between those given 10 mg/kg BW eel’s head powder and those receiving placebo; however, no such difference was found between those in the 5 mg/kg BW eel’s head powder group and placebo group. Eel’s head powder administration could increase plasma tryptophan level and reduce geriatric depression scale score among older individuals who suffered from depression. Administration of 10 mg/kg BW eel’s head powder was significant in increasing plasma tryptophan level and reducing GDS score.

Trans-acting role of the leader peptide peTrpL in posttranscriptional regulation of multiresistance

Bacterial ribosome-dependent attenuators are widespread posttranscriptional regulators. They harbour small upstream ORFs (uORFs) encoding leader peptides, for which no functions in trans are known yet. In the soil-dwelling plant symbiont Sinorhizobium meliloti, the tryptophan biosynthesis gene trpE(G) is preceded by the uORF trpL and is regulated by transcription attenuation according to tryptophan availability. However, trpLE(G) transcription is initiated independently of the tryptophan level in the cell, thereby ensuring a largely tryptophan-independent production of the leader peptide peTrpL. We provide evidence that peTrpL plays a role in the differential posttranscriptional regulation of the smeABR operon encoding the major multidrug efflux pump SmeAB and the TtgR-type transcription repressor SmeR. We show that peTrpL is involved in a tetracycline-dependent smeR mRNA destabilization and forms an antibiotic-dependent ribonucleoprotein (ARNP) complex with smeR and its antisense RNA (asRNA). Induction of asRNA transcription, ARNP formation and smeR downregulation were promoted by several antibiotics and the flavonoid genistein, and the resistance to these antimicrobial compounds was increased by peTrpL. The role of peTrpL in resistance is conserved in other soil Alphaproteobacteria.

Kernel modifications and tryptophan content in QPM segregating generations

Maize has poor nutritional value due to deficiency of two essential amino acids - tryptophan and lysine. Although recessive opaque2 (o2) mutation significantly increases their content in the endosperm, incorporation of opaque2 into high yielding cultivars was not commercially successful, because of its numerous agronomic and processing problems due to soft endosperm. Quality protein maize - QPM has lately been introduced as opaque2 maize with improved endosperm hardness and improved agronomic traits, but mostly within tropical and subtropical germplasm. The ongoing breeding project at MRI includes improvement of MRI opaque2 lines and conversion of standard lines to QPM germplasm. The main selection steps in QPM breeding involve assessing kernel modifications and tryptophan level in each generation. Herein, we present the results of the analysis for these traits on F3 and BC1F1 generations of QPM x opaque2, opaque2 x QPM and standard lines x QPM crosses. The results showed that the majority the genotypes had kernel types 2 and 3 (good modifications). The whole grain tryptophan content in F3 and BC1F1 genotypes of crosses between QPM and opaque2 germplasm was at the quality protein level, with a few exceptions. All BC1F1 genotypes of standard lines x QPM had tryptophan content in the range of normal maize, while majority of F3 genotypes had tryptophan content at level of QPM. The progeny (with increased tryptophan levels) of QPM and opaque2 crosses had significantly higher tryptophan content compared to the progeny of crosses between standard and QPM lines - 0.098 to 0.114 and 0.080, respectively. All genotypes that had poorly modified kernels and/or low tryptophan content will be discarded from further breeding.