Researchers from the School of Chinese Medicine (SCM) at Hong Kong Baptist University (HKBU) have discovered that the natural compounds found in two orchid species can effectively lighten skin and protect it from damage. Also commonly known as the Chinese medicinal herbs Shi Hu（石斛）, the two orchids – namely Dendrobium officinale（鐵皮石斛）and Dendrobium nobile（金釵石斛）– both contain a class of natural compounds called stilbenoids which have a potent antioxidant and anti-melanogenic function making them ideal for use in skin care products.
The study, which is published in the internationally-renowned European Journal of Medicinal Chemistry, was led by Professor Zhang Hongjie from the School’s Teaching and Research Division. It also involved Dr Tsang Siu-wai, Research Assistant Professor, and Drs Zhu Yu and Pan Wenhui, post-doctoral research fellows. The project has been granted a US patent with one PCT patent pending. It has long been suggested that molecules known as free radicals and reactive oxygen species play an important role in ageing. Although naturally produced by the body, when exposed to ultraviolet light from the sun their levels can rise, causing damage. Having extracted the stilbenoids from the two Dendrobium species, the research team found that the natural compounds successfully reduced the generation of free radicals and reactive oxygen species in both cellular and animal models, illustrating their suitability for protecting the skin against the effects of ageing.
The study also found that these natural stilbenoids compounds notably reduced melanin formation – the pigment that gives human skin its colour – by inhibiting an enzyme involved in its production. As a result, the finding illustrates that such natural compounds can achieve better results than vitamin C, vitamin E and beta hydroxy acid (BHA), which are commonly used in skincare products, when it comes to reducing melanin formation and the prevention of skin darkening. Dr Tsang Siu-wai explained that while many people love to sunbathe, prolonged exposure to the sun can cause great damage to skin and ultraviolet light from the sun may even affect certain genes that control the growth and division of the skin cells, leading to skin cancer.
Dr Tsang said: “Our study shows that the natural stilbenoids compounds in Shi Hu do not cause any irritation to skin. They carry highly effective anti-oxidative and anti-melanogenic functions, and can therefore be used as an effective component in developing pharmacological products for skin protection and anti-aging, as well as the prevention of skin darkening and melanoma. Currently, vitamin C, vitamin E and BHA are the antioxidants commonly used in the skincare products, but the natural compounds extracted from the two Dendrobium orchids are safer and more effective, and therefore have a high value as a skin protecting agent.”
The research team has received funding from the Innovation and Technology Commission of the HKSAR Government to establish a company called Gihon Biotech Limited, to commercialise the research. The researchers are also planning to explore the long-term effects of stilbenoids and in particular their anti-oxidative and anti-melanogenic functions. In the future, the team plans to study the effects of such compounds in the treatment of diseases which arise from oxidative stress, such as inflammation and cancer. The research project also won the second prize for start-up projects and the second prize for business plan projects respectively at the “Challenge Cup” National Competition (Hong Kong Regional Final) in 2017 and 2018.