The effects of 5-hydroxytryptophan on carrageenan-induced mouse paw oedemas / Efeito de 5-hidroxitriptofano no edema de pata de camundongo induzido por carragenina

ABSTRACT Objective 5-Hydroxytryptophan is the precursor compound of serotonin biosynthesis. The oral absorption of 5-Hydroxytryptophan is close to 100% and, unlike serotonin, it crosses the blood-brain barrier freely. 5-Hydroxytryptophan has been used as a food supplement for many years to treat anxiety and depression. Recent studies have shown that 5-Hydroxytryptophan suppresses the pro-inflammatory mediators and is effective in some inflammatory diseases, such as arthritis and allergic asthma. However, the role of 5-Hydroxytryptophan supplements on acute peripheral inflammation has not been investigated yet. In this study, the in vivo anti-inflammatory activity of 5-Hydroxytryptophan was evaluated with a carrageenan-induced paw oedema test in mice. Methods For the investigation of the acute antiinflammatory activity, single oral doses of 5-Hydroxytryptophan (1.5, 5 and 20mg/kg) were given to mice 1.5 hours prior to the carrageenan test. For chronic activity, the same oral doses were administered daily for two weeks prior to the carrageenan test on the 14th day. To induce inflammation, 0.01mL of 2% carrageenan was injected into the paws of mice. Results Supplementation with 5-Hydroxytryptophan significantly reduced inflammation in a dose-independent manner which was irrespective of the duration of exposure (per cent inhibition in acute experiments was 35.4%, 20.9%, 24.0%, and per cent inhibition in chronic experiments was 29.5%, 35.3%, 40.8% for the doses of 1.5, 5, and 20mg/kg, respectively). Conclusion Our findings demonstrate for the first time that 5-HTP supplements have the potential of suppressing the measures of acute peripheral inflammation. It is suggested that, apart from several diseases where serotonin is believed to play an important role, including depression, patients with inflammatory conditions may also benefit from 5-HTP.

RESUMO Objetivo O 5-hidroxitriptofano (5-HTP) é o composto precursor da biossíntese da serotonina. A absorção oral do 5-HTP é próxima a 100% e, ao contrário da serotonina, atravessa a barreira hematoencefálica livremente. O 5-HTP tem sido usado como suplemento alimentar por muitos anos na ansiedade e na depressão. Estudos recentes demonstraram que o 5-HTP suprime os mediadores pró-inflamatórios e é eficaz em algumas doenças inflamatórias, como artrite e asma alérgica. No entanto, o papel dos suplementos de 5-HTP na inflamação periférica aguda ainda não foi investigado. Neste estudo, a atividade anti-inflamatória in vivo do 5-HTP foi avaliada por meio do teste de edema de pata induzido por carragenina em ratos. Métodos Para a atividade aguda, doses orais únicas de 5 -HTP (1,5, 5 e 20 mg/kg) foram dados aos ratos 1,5 horas antes do teste da carragenina. Para a atividade crônica, as mesmas doses orais foram dadas cada dia durante duas semanas antes do teste da carragenina no 14º dia. 0,01ml da carragenina a 2% foi injetado nas patas dos ratos a fim de induzir a inflamação. Resultados A suplementação com 5-HTP reduziu significativamente a inflamação de uma maneira independente da dose, que foi independente da duração da exposição (por cento de inibição em experimentos agudos; 35,4%, 20,9%, 24,0% e por cento de inibição em experimentos crônicos; 29,5%, 35,3%, 40,8% para as doses de 1.5, 5 e 20 mg/kg respectivamente). Conclusão Nossas conclusões demonstram pela primeira vez que os suplementos de 5-HTP têm potencial para suprimir os sintomas de inflamação periférica aguda. É sugerido que, além de várias doenças em que se acredita que a serotonina tem uma função importante, incluindo a depressão, os pacientes com doenças inflamatórias também podem se beneficiar do 5-HTP.

6-pyruvoyl tetrahydropterin synthase deficiency: a case report.

A 5 day old girl screened positive for hyperphenylalaninemia on routine newborn screening. Initial diagnostic work-up showed elevated blood phenylalanine of 1100 mmol/L and low tyrosine. Limited protein diet and phenylalanine-free formula were prescribed. Further investigation revealed a defect in biopterin metabolism. Urine had no detectable biopterin (BH4) and an elevated level of neopterin at 24.31 mmol/mole Cr. Enzymatic assay showed zero level of 6-pyruvoyl tetrahydropterin synthase. The activity in the mother was 3.5 or 19.9% of controls consistent with heterozygosity. The concentrations of 5-hydroxyindoleacetic acid and homovanillic acid in the cerebrospinal fluid were below the reference ranges. A treatment regimen of BH4 tablets, 5 hydroxytryptophan and DOPA was initiated. The diagnostic evaluation, management and follow-up of patients with this disorder will be outlined. This is the first reported case of a Filipino with a defect in biopterin metabolism.

Effect of some chemical radioprotectors on mouse bone marrow.

Effect of HT, AET and Se on mice bone marrow has been studied by counting bone marrow micronucleated cells and endogenous spleen colony count (CFU-S). Combination of HT and AET used as a radioprotector has not caused any significant variation in any of the parameter studied when administered once, it increases bone marrow micronucleated cells and decreases CFU-S slightly after daily administration for 7 days. The individual constituent of the combination administered singly does not increase micronucleated cell number. Seven consecutive doses of HT + AET and same in combination with Se enhances micronucleated cells to a higher level. Daily injection of Se alone up to 7 days also causes an increase in micronucleated cells upto same level. CFU-S pool does not show any significant change in number of bone marrow cells through out the study except in the groups where animals were treated with Se.

Use of hydroxylamine in improving radio protection of a combination of 5-hydroxy L-tryptophan and a thiol compound (AET) in small mammals.

Radioprotective effectiveness has been evaluated by 30 day survival studies and protection to bone-marrow cells in mice after radiation exposure and this has been further established by 24 hr deoxycytidine excretion in urine of rats following 5 Gy whole body gamma irradiation and protection to superoxide dismutase enzyme in marrow cells and red blood corpuscles. Radioprotective effectiveness as well as the duration of radioprotection have been improved by the administration (ip) of hydroxylamine (20 mg/kg), a decarboxylase inhibitor, prior to the use of a combination of 5-hydroxy L-tryptophan (5-HTP, 70 mg/kg) and 2-aminoethylisothiuronium bromide hydrobromide (AET, 20 mg/kg) ip in small mammals before whole body gamma irradiation.

Protection to glycolysis by a combination of 5-hydroxy-L-tryptophan and 2-aminoethylisothiuronium bromide hydrobromide in lethally irradiated rats.

Rate of glycolysis in vivo at different time intervals following 8 Gy [LD100(30)] whole body gamma radiation (WBGR) was evaluated by estimating liver glycogen, blood sugar, serum lactic dehydrogenase (LDH) and blood lactic acid concentration in adult male Sprague Dawley rats. Within 1 hr of radiation exposure, a significant fall in liver glycogen was observed in rats fed food and water ad libitum. The glycogen content increased after 24 hr and had returned to control level on 7th day after radiation exposure. Blood sugar, serum LDH and blood lactate levels increased significantly as compared to non irradiated controls. Pretreatment with 5-hydroxy-L-tryptophan (5-HTP; 100 mg/kg) + 2-aminoethylisothiuronium bromide hydrobromide (AET; 20 mg/kg) ip 30 min before 8 Gy WBGR, modified these values and restored them to normal level on 7th day post-irradiation.