Allantoin chemicals used in cosmetics, cream
April 16 2016 by Ray Sahelian, M.D.
Allantoin is an oxidative end product of purines in mammals. The small amount present in human plasma or serum results from free radical action on urate and may provide a stable marker of in vivo free radical activity. Allantoin is also a plant extract of the comfrey plant and is used as a cream in cosmetic products for its soothing and anti-irritating properties. Allantoin extract can be found in anti-acne products, sun care products, and clarifying lotions.
Allantoin and uric acid
The diureide of glyoxylic acid is a crystallizable oxidation product of uric acid found in allantoic and amniotic fluids, in fetal urine and in many plants. (Ureide is a compound derived from urea and contains acid radicles. Those from one molecule of urea, as alloxan, are monoureides; those derived from two, as uric acid, are diureides). Allantoin is an urinary excretion product of purine metabolism in most mammals but not in higher apes including humans. It is produced synthetically by the oxidation of uric acid. Allantoin is active in skin-softening (keratolytic effect) and rapid cell regeneration by precipitating proteins on skin. It is used as an abrasive and astringent agent in the end products include cosmetic lotions, creams, suntan products, scalp preparations, shampoos , lipsticks and and various aerosol preparations. It is used in topical pharmaceutical preparations. Allantoin has been used in various oral hygeine preparations such as toothpaste and mouthwash as well as in eye drops to treat watering eyes and in ear drops to clean the ear canal.
In plants the ureides allantoin and allantoic acid (ALA) are formed in purine metabolism, and in some legumes both compounds play an important role as nitrogen (N) sources. In coffee plants, Allantoin and ALA are catabolites of caffeine degradation. Caffeine is found throughout the coffee plant and in some parts this alkaloid can accumulate up to 4% dry basis. Therefore, caffeine degradation via ureides may make an important contribution to N metabolism of the plant.
Allantoin and Behcet's disease
Evaluation of allantoin levels as a new marker of oxidative stress in Behcet's disease.
Scand J Rheumatol. 2006. Department of Biochemistry, Faculty of Pharmacy, Gazi University, Etiler, Ankara, Turkey.
The increased production of reactive oxygen species from activated neutrophils in Behcet's disease and recurrent aphthous stomatitis (RAS) may result in increased oxidative stress. Uric acid can react rapidly with neutrophil-derived ROS to form allantoin. The purpose of the study was to evaluate the serum levels of allantoin as a new marker of oxidative stress in BD compared with malondialdehyde (MDA) levels as a well-known marker. Blood samples were obtained from 23 BD patients, 22 RAS patients as positive controls, and 21 healthy controls. When compared to the healthy controls, we found higher allantoin and MDA levels in the BD patients and higher MDA levels in the RAS patients. Serum ascorbic acid levels in the BD patients were significantly lower than in the controls. Increased allantoin and MDA levels suggest the possible involvement of free radicals in BD. As allantoin is only a product of uric acid oxidation by reactive oxygen and nitrogen species, it may also be used as a marker of oxidative stress in BD.
J Pharm Biomed Anal. 2014. Changes in urinary metabolic profile after oral administration of curcuma extract in rats. The diffusion of phytochemicals in health promoting products is growing, but studies related to their effects on healthy subjects are still lacking despite the large consumption of natural products as nutraceuticals or food supplements. In many cases, research supports the in vitro antioxidant activity of phytochemicals, but the health claims attributed to the final marketed nutraceutical products have dubious scientific foundation. Also, studies focussed on the definition of their biological targets and mechanisms of action can be useful to assess their efficacy and safety. In this study, the effect of oral administration of 80mg/kg of Curcuma longa Linn. extract to 12 healthy rats over 25 days was evaluated by monitoring the changes of urinary composition. 24-h urine was collected during the animal experiment and the composition was analyzed. The two datasets were studied individually through a metabolomic approach and the multivariate analysis revealed significant differences between the control and the treated group. Curcumin levels were also measured in 24-h urine samples by HPLC-MS. Both the (1)H NMR and the HPLC-MS dataset showed that the administration of 80mg/kg of Curcuma longa extract to healthy animals induces changes in urinary composition. Decreased allantoin urinary levels can be considered a partial demonstration of the in vivo effect of curcumin on oxidative stress in a healthy animal model.