Determination of Antioxidant Effect of Cosmetics by Nitrotetrazolium Blue Chloride (NBT) Method

As an important chemical reagent, Nitrotetrazolium blue chloride (NBT) is not only widely used in biochemical experiments, clinical in vitro diagnosis and other fields, but also has a great effect in the detection of the antioxidant efficacy of cosmetics.

Antioxidant is one of the hottest words in the beauty and skin care industry. Antioxidants are the key components of cosmetics to have an antioxidant effect. They can react with common free radicals in the body such as hydroxyl free radicals and superoxide anion free radicals to prevent Lipid peroxidation has the functions of removing spots, whitening, anti-wrinkle and anti-aging. Using the NBT method to determine the antioxidant activity or the elimination rate of active oxygen is an important reference for evaluating the antioxidant effect of cosmetics.

In the patent CN105267268A^[1], in order to determine the antioxidant effect, the researchers used the NBT method to measure the active oxygen generated by xanthine and xanthine oxidase, and evaluate the effect of the test substance in eliminating active oxygen, that is, the effect of eliminating active oxygen. Active oxygen is generated by xanthine and xanthine oxidase. The elimination rate of active oxygen was measured by measuring the blue color produced by the reaction of these active oxygen with NBT at a wavelength of 560 nm.

In cosmetic antioxidants, SOD, vitamin C, vitamin E, etc. are all familiar names. SOD, or superoxide dismutase, as an antioxidant can make cosmetics have the effect of delaying skin aging and removing spots. Many domestic and foreign cosmetics brands have added a certain percentage of SOD to their products. Such as Estee Lauder pomegranate water from France, SKII from Japan, and domestic SOD honey. The NBT method can determine SOD activity. The principle is that nitrogen blue tetrazolium undergoes a photochemical reduction reaction in the presence of methionine and riboflavin to produce blue methylhydrazone. The blue methylhydrazone has the maximum light absorption at 560nm. SOD can inhibit the photochemical reduction of NBT, and its inhibition intensity is proportional to the enzyme activity within a certain range.

Wang Lili et al. ^[2] used the NBT method to determine the ability of a new type of cosmetic antioxidant: DP5-8 chitooligosaccharide to scavenge superoxide anions, and verified that DP5-8 chitooligosaccharide has a strong antioxidant capacity and resistance to hydroxyl radicals and superoxide.

references:

1.Ginseng leaf extractive manufacturing method and cosmetic composition comprising ginseng leaf extractive serving as effective ingredient.  CN105267268A

2.Preparation method of chitosan oligosaccharide with specific degree of polymerization and application of chitosan oligosaccharide to cosmetics.CN110387392A