Sunburn is a commonplace dermal ailment with a variety of treatments like corticosteroids and NSAIDs that were developed to treat acute cases.
However, the researchers cited complaints such as poor healing efficacy and a long recovery time associated with them. “The development of more effective drugs to cure sunburn is still in great need.”
Collagen is the major component of the dermis and collagen degradation has been identified as a critical feature of acute sunburn. Collagen has been found to play a critical role in almost the entire process of wound repair.
Animal collagen has been widely used in the treatment of skin wounds due to characteristics such as high biocompatibility and bioactivity.
What makes yak a unique cattle species, is that it lives primarily on plateaus with excessive UV exposure, prompting researchers to study its ability to heal sunburnt skin.
“Compared with low-altitude cattle, yak has been found to be enriched in protein domains involved in sensing the extracellular environment and hypoxic stress after thousands of years of adaption,” said the team, which comprised of researchers from Lanzhou University and Gansu Engineering Research Centre of Medical Collagen.
Yak of all trades
According to the study, yak collagen type I displays a “perfect triple-helix structure” with a melting temperature of 42.7C.
“YCI is highly biocompatible, and it remarkably promotes the proliferation and adhesion of human skin fibroblasts,” said the study.
According to the team, this was the first time non-denatured type I collagen has been extracted from yak hide.
Non-denatured type I collagen was made into a cream and a dressing. These were tested on UV-irradiated mice as well as a control group.
Over four days, the yak collagen treatment resulted in “robust revitalisation of sunburned mice skin evidenced by prominent acceleration of epithelisation and collagen deposition.”
Additionally, there was a significant increase of hydroxyproline content in the yak collagen-treated sunburned skin, affirming the enhanced regeneration of collagen. Furthermore, the team also observed faster recovery time.
Meanwhile, the untreated group showed epidermal damage, cellular infiltration, and dermal inflammation.
The researchers concluded that yak type I collagen was effective in treating sunburnt skin and noted that it could have broader skin care applications.
“[Yak type I collagen] may contribute to sunburn healing by promoting the regeneration of intact collagen as well as directly replenishing the dermal collagen. The highly biocompatible and bioactive non-denatured yak collagen and its composite products provide potent treatments of sunburn, which have broad applications in cosmetics and dermatology.”
Non-denatured yak type I collagen accelerates sunburned skin healing by stimulating and replenishing dermal collagen
Caihong Fu et al.