Page 186 - Cosmetology

regulations mandated by the FDA. Active ingredients must be listed first on an ingredient label. The amount
and exact function of each active ingredient is controlled and must be approved by the FDA. Active
ingredients are considered to have a pharmacological altering effect on skin, and these effects must be
documented by scientific evaluation and approved by the FDA. Active ingredients include such substances
as sunscreen ingredients, skin-lightening agents, and benzoyl peroxide. See inactive ingredient.

adenine. Component of DNA that carries genetic information to the cell. See DNA.

adenosine triphosphate. An organic compound from adenosine, which is formed by the hydrolysis of yeast
nucleic acids. All living things need a continual supply of energy in order to function. Animals obtain their
energy by oxidizing foods, plants obtain energy by using chlorophyll to trap sunlight. However, before the
energy can be implemented, it must first be changed into a form that the organism can readily use. This
special form, or carrier of energy, is the molecule adenosine triphosphate (ATP). In humans, ATP serves as
the major energy source within the cell to drive a number of biological processes such as protein synthesis.
The cell breaks down ATP by hydrolysis to yield adenosine diphosphate (ADP), which is then further broken
down to yield adenosine monophosphate (AMP). Research into topically applied adenosine triphosphate is
just beginning, but it appears to have strong potential as a cell-communicating ingredient and as an
inflammation modulator
adipic acid/neopentyl glycol/trimellitic anhydride copolymer. A synthetic polymer. See film-forming
agent.

advanced glycation endproduct. Advanced glycation endproducts, also known as AGEs, are caused by
the body's major fuel source, namely glucose. This simple sugar is essential for energy, yet it also can bind
strongly to proteins (the body's fundamental building blocks) and form abnormal structures (AGEs) that
progressively damage tissue elasticity. Once AGEs are generated, they begin a process that prevents many
systems from behaving normally by literally causing tissue to cross-link and become hardened. The theory is
that by breaking these AGE bonds you can undo or stop the damage they cause. There are studies showing
aminoguanidine and carnosine to be AGE inhibitors that can prevent glucose cross-linking of proteins and
the loss of elasticity associated with aging and diabetes, but many other substances are potential candidates
as AGE inhibitors as well. One study examined over 92 substances and 29 of them showed some degree of
inhibitory activity, with 9 compounds proving to be 30 to 40 times stronger than aminoguanidine. AGE and
free-radical damage may be inextricably linked, but none of this has been shown to have relevance when it
comes to topical application of these substances when they are included in cosmetics.

Aerocarpus santalinus. See red sandalwood.

Aesculus hippocastanum. See horse chestnut.

agar. See algae.

Agaricus bisporus extract. An extract of mushroom that is thought to help regulate skin cell production by
inhibiting cell growth, particularly for use in psoriasis, but research in this regard is mixed. Internally, there is
research showing it can inhibit the growth of breast cancer cells and colon cancer cells.

AGE. See advanced glycation endproduct.

age spot. There is no such thing as an "age spot." The skin can develop brown patches for many reasons,
but the characteristic small ones on the hands, arms, and face are caused by sun damage. These are
possibly indications of precancerous conditions and should be watched carefully for changes. See melasma.

Agrimonia eupatoria leaf extract. Research shows this plant extract inhibits the hepatitis b virus and has
antioxidant properties. Whether or not it has a benefit when applied topically is not known. There is no
research showing it to be effective for cellulite.

AHA. Acronym for alpha hydroxy acid. AHAs are derived from various plant sources or from milk. However,
99% of the AHAs used in cosmetics are synthetically derived. In low concentrations (less than 3%) AHAs
work as water-binding agents. At concentrations over 4% and in a base with an acid pH of 3 to 4, these can
exfoliate skin cells by breaking down the substance in skin that holds skin cells together. The most effective
and well-researched AHAs are glycolic acid and lactic acid. Malic acid, citric acid, and tartaric acid may also
be effective but are considered less stable and less skin-friendly; there is little research showing them to
have benefit for skin.