Compendium of the most significant studies with reference to properties, intake, effects.
Becker LC, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Alan Andersen F. Final report of the safety assessment of allantoin and its related complexes. Int J Toxicol. 2010 May;29(3 Suppl):84S-97S. doi: 10.1177/1091581810362805.
Abstract. Allantoin is a heterocyclic organic compound. Allantoin ascorbate, allantoin biotin, allantoin galacturonic acid, allantoin glycyrrhetinic acid, allantoin panthenol, and allantoin polygalacturonic acid are complexes of allantoin. All of the ingredients in this review act as skin-conditioning agents. Allantoin was reported to be used in 1376 cosmetic products at concentrations up to 2%. There are data gaps regarding use and concentration of the remaining allantoin complexes. Ascorbic acid, biotin, glycyrrhetinic acid, and panthenol have been determined by the CIR Expert Panel to be safe. Galacturonic acid and polygalacturonic acid have not been reviewed by the CIR Expert Panel, and substantial data on these chemicals were not available. The safety test data in this safety assessment and in previous safety assessments were considered sufficient to support the safety of allantoin and the allantoin complexes in product categories and at concentrations reviewed in this safety assessment.
Kand'ár R, Záková P. Allantoin as a marker of oxidative stress in human erythrocytes. Clin Chem Lab Med. 2008;46(9):1270-4. doi: 10.1515/CCLM.2008.244.
Abstract. Background: Uric acid is the final product of purine metabolism in humans. It was determined that this compound has important antioxidative properties and it may be oxidized to allantoin by various reactive oxygen species. Therefore, the measurement of allantoin may be useful for the determination of oxidative stress in humans....Conclusions: Significant higher levels of allantoin in both plasma and erythrocytes of patients with chronic renal failure indicate that allantoin may be used as a good marker of oxidative stress.
Araújo LU, Grabe-Guimarães A, Mosqueira VC, Carneiro CM, Silva-Barcellos NM. Profile of wound healing process induced by allantoin. Acta Cir Bras. 2010 Oct;25(5):460-6. doi: 10.1590/s0102-86502010000500014.
Abstract. Purpose: To evaluate and characterize the wound healing process profile induced by allantoin incorporated in soft lotion oil/water emulsion using the planimetric and histological methods....Results: The data which were obtained and analyzed innovate by demonstrating, qualitatively and quantitatively, by histological analysis, the profile of healing process induced by allantoin. The results suggest that the wound healing mechanism induced by allantoin occurs via the regulation of inflammatory response and stimulus to fibroblastic proliferation and extracellular matrix synthesis. Conclusion: This work show, for the first time, the histological wound healing profile induced by allantoin in rats and demonstrated that it is able to ameliorate and fasten the reestablishment of the normal skin.
Fernandes J, de Amorim GC, da Veiga TE, Cardoso J, Arruda AC, Arruda MSP, Castelo-Branco MTL. Allantoin reduces cell death induced by cisplatin: possible implications for tumor lysis syndrome management. J Biol Inorg Chem. 2019 Jun;24(4):547-562. doi: 10.1007/s00775-019-01661-6.
Abstract. Massive lysis of tumor mass in cancer patients under chemotherapy regimens generates high levels of uric acid, leading to what is known as tumor lysis syndrome (TLS). Rasburicase, a recombinant urate oxidase, converts urate to allantoin, which is readily excreted by the kidneys. Even though there is a high production of allantoin from urate in cancer patients following rasburicase treatment, there are no studies on how allantoin excess could interfere with chemotherapy. We have evaluated allantoin interference with cisplatin efficiency on the lung cancer cell line H460 in vitro. The cells were treated with cisplatin (33 µM), with or without allantoin, for 48 h, in the presence or absence of UV light, and N-acetyl-L-cysteine (NAC) for 24 h. Cell viability, cell cycle, ROS production, apoptosis and immunoblot assays were performed. We showed that allantoin reduced the apoptosis induced by cisplatin in the H460 cell line. However, the activity of carboplatin and oxaliplatin, betulinic acid, TIBA, UV and H2O2 was not affected by allantoin. NMR spectroscopy showed that allantoin reduces cisplatin activity through direct interaction with cisplatin.
Nishinami S, Yoshizawa S, Arakawa T, Shiraki K. Allantoin and hydantoin as new protein aggregation suppressors. Int J Biol Macromol. 2018 Jul 15;114:497-503. doi: 10.1016/j.ijbiomac.2018.03.011.
Abstract. Allantoin is widely used in pharmaceutical and cosmetic products, and is composed of a hydantoin ring and a ureido group. Recent reports showed that allantoin suppresses thermal aggregation of hen egg white lysozyme (LYZ). However, structural insight into the properties of allantoin on protein aggregation and whether allantoin controls the aggregation of other proteins under different stress conditions remain unclear. Here we studied the structural properties of allantoin in terms of its effects on protein aggregation by comparing allantoin with urea and hydantoin....Copyright © 2018 Elsevier B.V.
Nokoorani YD, Shamloo A, Bahadoran M, Moravvej H. Fabrication and characterization of scaffolds containing different amounts of allantoin for skin tissue engineering. Sci Rep. 2021 Aug 9;11(1):16164. doi: 10.1038/s41598-021-95763-4.
Abstract. Using the skin tissue engineering approach is a way to help the body to recover its lost skin in cases that the spontaneous healing process is either impossible or inadequate, such as severe wounds or burns. In the present study, chitosan/gelatin-based scaffolds containing 0.25, 0.5, 0.75, and 1% allantoin were created to improve the wounds' healing process. ...© 2021. The Author(s).
Chen MF, Tsai JT, Chen LJ, Wu TP, Yang JJ, Yin LT, Yang YL, Chiang TA, Lu HL, Wu MC. Antihypertensive action of allantoin in animals. Biomed Res Int. 2014;2014:690135. doi: 10.1155/2014/690135.
Abstract. The agonists of imidazoline I-1 receptors (I-1R) are widely used to lower blood pressure. It has been indicated that guanidinium derivatives show an ability to activate imidazoline receptors. Also, allantoin has a chemical stricture similar to guanidinium derivatives. Thus, it is of special interest to characterize the effect of allantoin on I-1R. In conscious male spontaneous hypertensive rats (SHRs), mean blood pressure (MBP) was recorded using the tail-cuff method. Furthermore, the hemodynamic analyses in catheterized rats were applied to measure the actions of allantoin in vivo. Allantoin decreased blood pressures in SHRs at 30 minutes, as the most effective time. Also, this antihypertensive action was shown in a dose-dependent manner from SHRs treated with allantoin. Moreover, in anesthetized rats, allantoin inhibited cardiac contractility and heart rate as showing in hemodynamic dP/dt max significantly. Also, the peripheral blood flow was markedly increased by allantoin. Both actions were diminished by efaroxan at the dose sufficient to block I-1R. Thus, we suggest that allantoin, as I-1R agonist, has the potential to develop as a new therapeutic agent for hypertension in the future.
Valle KZM, Saucedo Acuña RA, Ríos Arana JV, Lobo N, Rodriguez C, Cuevas-Gonzalez JC, Tovar-Carrillo KL. Natural Film Based on Pectin and Allantoin for Wound Healing: Obtaining, Characterization, and Rat Model. Biomed Res Int. 2020 Oct 17;2020:6897497. doi: 10.1155/2020/6897497.
Abstract. Introduction: In our days, several approaches reported the use of natural compounds in medical applications. Among them, pectin and allantoin are nontoxic, biocompatible, and biodegradable; however, its use for possible wound healing therapeutics is still limited. Pectin and allantoin have been applied in pharmaceutical industry and beauty cosmetic and could be also applied as scaffolds for tissue regeneration, wound healing, and so on. The aim of this study was to combine by the first time two natural ingredients to develop a new biomaterial to treat skin injuries in a rat model....Copyright © 2020 Karen Zulema Meza Valle et al.
Gruber J, Tang SY, Jenner AM, Mudway I, Blomberg A, Behndig A, Kasiman K, Lee CY, Seet RC, Zhang W, Chen C, Kelly FJ, Halliwell B. Allantoin in human plasma, serum, and nasal-lining fluids as a biomarker of oxidative stress: avoiding artifacts and establishing real in vivo concentrations. Antioxid Redox Signal. 2009 Aug;11(8):1767-76. doi: 10.1089/ars.2008.2364.
Abstract. Urate is the terminal product of purine metabolism in primates, including humans. Urate is also an efficient scavenger of oxidizing species and is thought to be an important antioxidant in human body fluids. Allantoin, the major oxidation product of urate, has been suggested as a candidate biomarker of oxidative stress because it is not produced metabolically. Although urate is converted to allantoin under strongly alkaline pH, such conditions have been used in the past to facilitate extraction of allantoin. We evolved a method for the determination of allantoin concentrations in human plasma and serum by gas chromatography-mass spectrometry without such artifact. With this method, we show that alkaline conditions do indeed cause breakdown of urate, leading to significant overestimation of allantoin concentration in human samples. By using our alternative method, serum samples from 98 volunteers were analyzed, and allantoin levels were found to be significantly lower than was previously reported. The in vivo utility and sensitivity of our method was further evaluated in human nasal-lining fluids. We were able to demonstrate an ozone-induced increase in allantoin, in the absence of increases in either ascorbate or glutathione oxidation products.
Conti V, Corbi G, Iannaccone T, Corrado B, Giugliano L, Lembo S, Filippelli A, Guida M. Effectiveness and Tolerability of a Patch Containing Onion Extract and Allantoin for Cesarean Section Scars. Front Pharmacol. 2020 Sep 25;11:569514. doi: 10.3389/fphar.2020.569514.
Abstract. Background: The prevention or early treatment of pathological scars is the most appropriate therapeutic approach. Gels and patches containing onion extract and allantoin are safe and effective in patients with scars of various origins and severity. However, no controlled studies have evaluated the effects of the patch formulation in women after Cesarean delivery. This study aimed to investigate the effects of a patch containing Allium cepa and allantoin on Cesarean section (C-section) scars.....Conclusions: Intense treatment of just 4 weeks with a patch containing Alium Cepa extract and allantoin was able to improve pigmentation, relief, and pliability of C-section scars in women with a history of C-section.
Allantoin 
