The Washington, US-based company is positioning the Nivitol ingredient, based on an extract of Dianella ensifolia, as an alternative to whitening agents such as kojic acid and hydroquinone.
Tyrosinase inhibitor
While it uses the same mode of action as kojic acid, they both inhibit the enzyme tyrosinase, the company claims it is significantly more effective.
Comparing the effective concentrations of a number of whitening agents in topical applications, the company notes that Nivitol is effective at the lowest concentration (0.05 percent) compared to 2 percent for kojic acid from fungal sources, and 1 percent for cinnamic acid.
This lower effective concentration means it can be a cost-effective alternative for formulators, the company said.
Melanin synthesis
Tyrosinase is an enzyme involved in the production of melanin, a dark pigment the quantity and quality of which affects skin color. Inhibiting this enzyme helps reduce melanin production and therefore lead to a lighter skin colour.
The efficacy of Nivitol as a skin whitener was first tested against the mushroom form of the enzyme tyrosinase, which is often used to test for potential whitening ingredients.
Unigen then tested it against mammalian tyrosinase. Human melanocytes were treated with different concentrations of Nivitol and kojic acid and the company claims Nivitol inhibited the tyrosinase’s activity at significantly lower concentrations than kojic acid.
In addition, the company tested its ingredient on the reconstructed human skin model, Melanoderm. Consisting of normal, human derived epidermal keratinocytes and melanocytes, the reconstructed skin tissues are grown on a porous membrane that the company says makes it possible to mimic the topical application of the active substance.
Application of a 0.5 percent concentration of Nivitol showed a 43 percent reduction in melanin synthesis, whereas a 1 percent concentration of kojic acid showed a 36 percent reduction. The company also said neither treatment had any effect on cell viability.
Adverse side effects have dogged the history of some of the more common skin whitening agents, culminating in a ban of hydroquinone in cosmetics formulations in some regulatory areas.
Unigen was quick to point out that no adverse side effects have been shown for Nivitol.