Skin brightening efficacy of Saururus chinensis extract

Likewise, the synthetic drug used to reduce melanin is also undesirable due to its side effects in human cells. As an alternative, a botanical product was developed from Saururus chinensis for whitening purposes and investigated in Murine B16F1 melanoma cell in vitro. Its formulated product (Natural Skin Renewal) was tested clinically on female subjects in a placebo-controlled trial. The result showed that S. chinensis extract is able to reduce the tyrosinase activity by 35% at a concentration of 100 mg/mL. In a clinical study, the formulated cream (Natural Skin Renewal) decreased the melanin index value by 44% in 56D and the individual typology angle (ITA˚) value was increased significantly compared to that of placebo (control). Overall, the Natural Skin Renewal cream which contains S. chinensis extract may have a promising potential for use as an effective whitening agent on human skin.

Melanin is a pigment produced in a specialised group of cells known as melanocytes. In humans, melanin is the primary determinant of skin colour and it is present in all the parts of body. Melanin is thought to protect skin cells from UV radiation damage. However, excessive melanin (hyperpigmentation) is undesirable since it may cause a darker or unfair skin. It is known that the tyrosinase enzyme is responsible for melanin production. Therefore, inhibition of tyrosinase activity can prevent melanin production in human epidermal cells.

Several plant extracts or phytocompounds were found to suppress the melanigenisis by inhibiting tyrosinase enzymes activity.^1–3 Saururus chinesis which belongs to the family Saururaceae is a perennial herb and is also called ‘lizard’s tail’. The plant is cosmopolitan in the Asian region.⁴ It is reported that the whole plant is used as an antiphlogistic, depurative, diuretic, febrifuge and refrigerant. Its decoction is used in the treatment of oedema, nephritis-associated oedema, nutritional oedema, rheumatoid arthritis, boils and abscesses, rashes and fungal infections of the skin.⁵ Recently, the plant has showed its potential in antioxidant, anti-inflammatory, anti-angiogenic and anti-nociceptive activities.^6–8 The plant is rich in phytochemicals, especially flavonoids.⁹ Knowing the previous report, our main objective was to evaluate the efficacy of the plant extract on skin melanin synthesis inhibition activity in vitro and also to test (clinically) the whitening effect of formulated cream (Natural Skin Renewal) containing S. chinensis extract.