Introduction

Allantoin is a naturally occurring active ingredient found in the human body and in a variety of plants (e.g., comfrey, horse chestnut, and bearberry). Allantoin is widely used in cosmetics as a moisturiser for the treatment or prevention of dry, rough, scaly, itchy skin and minor skin irritations (e.g., diaper rash, skin burns from radiation therapy). Allantoin is also used as an emollient to help soften and moisturise the skin and reduce itching and flaking.

Figure 1 Characteristics of Allantoin

Benefits of Allantoin

Allantoin is an endogenous substance in the body that has been shown to promote healthy tissue proliferation by promoting cell proliferation and extracellular matrix synthesis. It may also play a role in tissue formation and differentiation, particularly in stimulating granulation tissue development and epithelialisation. As such, it may be added to skin care products to soothe irritation and protect minor cuts, scrapes and burns. In addition, it has a variety of skin care benefits such as moisturising, anti-ageing, antiseptic, dissolving the stratum corneum and reducing irritation.

Allantoin has been documented to increase lipogenesis in liver energy target muscles. Allantoin has an inhibitory effect on collagenase and may improve the aging process. Allantoin is cytotoxic to prostate, colon, intestinal ovarian and breast cancers, and weakly inhibits laryngeal cancer. Allantoin may be a key factor in improving health and aging and protecting against cancer under stressful conditions such as physical activity and radiation hazards.

Applications of Allantoin

Allantoin has been reported to be a promising biomarker for monitoring oxidative stress in humans and is widely used in various topical drugs and cosmetics. It is used in the treatment of burns, dermatitis, wounds, acne and impetigo, and also to reduce hyperkeratotic changes, erythema, infiltration, and the subjective symptoms of itching and burning in patients with psoriasis. It is also beneficial in fading scars. In addition, the chemiluminescence emission intensity of the fluorescein-allantoin system was 17 times higher than that of the classical fluorescein-hydrogen peroxide system. It may be an effective candidate for the construction of novel chemiluminescent systems and may offer a wide range of sensing applications.

In agriculture, it was found that allantoin accumulates significantly in the root system under drought stress. Under different concentrations of exogenous allantoin treatments, drought-resistant metabolites, including proline and soluble sugars, were significantly accumulated and reactive oxygen species (ROS) were reduced in the plants and reached significant levels at 100 μmol·L-1. And the allantoin-treated plants also had a stronger ability to scavenge reactive oxygen species in order to resist drought.