Turmeric is a popular herb derived from the roots of the turmeric plant found mainly in India and South Asia. Turmeric has a strong yellow colour and distinctive taste and can be used as a dye and spice in curry preparation. Turmeric and its purified curcumin extract are also said to have anti-inflammatory and antioxidant properties and can be used in medical research to treat digestive disorders, including diarrhoea and liver disease.
Curcumin is a highly pleiotropic molecule that affects many signaling pathways. It has anti-inflammatory, antioxidant, anti-microbial, hypoglycemic, wound healing, chemoprophylaxis, chemical sensitization and radiosensitization properties.
The yellow color of curcumin has been used in the food, textile and cosmetic industries and is often used as a food additive. Due to its similar color to synthetic tartrazine, it is a natural alternative. It is currently used to colour mustard, dairy products, pastries, soups, sauces, gravies, fish and cereals. However, it can only be used for certain foods and can be stored for short periods.
Turmeric may be the first known cosmetic, as it was traditionally applied to the skin by women. It has been reported to reduce facial hair growth, reduce acne and improve skin tone. Many women in Tamil Nadu still use turmeric on their faces before bathing every day. Tetrahydrocurcumin is the grayish hydrogenated form of curcumin and is used locally as a skin antioxidant. When added to humectants, it prevents rancidity of lipids. Curcumin, as an antioxidant, anti-inflammatory and skin brightening agent, shows great potential in cosmeceuticals. Curcumin can inhibit collagenase, elastase and hyaluronidase in vitro. Curcumin gel has been reported to improve the appearance of photodamaging skin conditions such as pigment changes, helioelastin, actinic podophyllopathy, helioformin and photokeratosis by prolonging phototherapy time. It has also been found to promote apoptosis in cells with DNA damage. Curcumin has also been evaluated as an environmentally friendly hair dye. And it may have great potential as an essential oil in perfumes, cosmetics and soaps.
Curcumin has the potential to treat skin irritation and vegetative diseases. Curcumin inhibits key psoriatic pathways in animal and in vitro studies. However, a small open-label study of patients with moderate to severe psoriasis showed that oral curcumin was less effective, possibly due to its reduced oral supply. Topical gel preparations containing 1% curcumin are known to inhibit phosphorylase kinase and improve the focus of chronic patchy psoriasis. In addition, it promotes healing and prevents scar formation in acute injuries such as burns by inhibiting phosphorylase kinase and subsequent inflammatory signaling pathways.
Scientific studies have shown that curcumin accelerates wound healing in rats due to its antioxidant properties. It increases granulation tissue, new blood vessel formation, and enhances the synthesis of components of the extracellular matrix, including collagen. Curcumin may have a potential role in scleroderma because it leads to selective apoptosis of lung fibroblasts affected by the disease. Curcumin, meanwhile, may be a promising antifungal agent against Candida. Therefore, it may also have anti-microbial, anti-parasitic and antiviral effects.
The use of turmeric dates back thousands of years, and the "yellow root" of turmeric is now deeply rooted in many cultures. There is a need for increased awareness of its traditional uses, benefits, adverse effects and more research on its more bioavailable preparations. In the future, this ancient spice will gradually enter the skin treatment of the future.