Wasabi Root Extract (INCI: Wasabia japonica Root Extract)

The wasabi plant, also known as Japanese horseradish in the West, is a member of the Brassicaceae family along with horseradish, cabbage, and mustard. It is native to Asia, specifically Japan, and grows naturally along riverbeds. The roots of the plant are used to make a pungent condiment that is best described as a hot mustard, but unlike most hot flavors that are based in capsaicin (such as that of chilies), the heat from wasabi is less on the tongue and more in the vapor that quickly travels into the nasal passages. In the West, commercial wasabi pastes and flavored products are usually derived from the related horseradish and mustard plants, and not actual wasabi root, due to less expensive cost.

The unique flavor of wasabi is a result of complex chemical mixtures from the broken cells of the rhizome that are released when finely grated. The chemical in wasabi that provides for its initial pungency is the volatile methylthioalkyl isothiocyanates (e.g. allyl isothiocyanate), which is produced by hydrolysis of natural rhizome thioglucosides (conjugates of the sugar glucose, and sulfur-containing organic compounds). The hydrolysis reaction is catalyzed by myrosinase and occurs when the enzyme is released on cell rupture from maceration, such as by the aforementioned grating og the plant's root rhizome.

In skincare formulations, wasabi extract offers a botanical source of several phytonutrient compounds that are extremely effective antioxidants in the skin. The extract of wasabi contains oxido-reductases, isocyanates, and glucosinolates. Of particular interest are the the oxido-reductases, which are specifically peroxidases, superoxide dismutases, and sinigrin (allyl isothiocyanate). Superoxide dismutase in conjunction with peroxidase is responsible for the scavenging and neutralization of both the superoxide and peroxide radicals which contribute to premature aging. Results from in vitro studies have demonstrated that sinigrin (allyl glucosinolate) directly inhibits oxidative reactions in DNA.