A peel by any name, you might think, is still exfoliation. In fact, it's likely you shrug off the "acid-or-enzyme" dilemma as a personal one, pick a favorite and stick with it. While both methods are excellent tools for intervening in the skin's natural desquamation process, the biological complexity inherent to enzymes means they possess properties and impart activities that are unique to themselves. Understanding the basics can help you customize your services to specifically accommodate any skin type or condition - and deliver the targeted results that bring clients back.

Erasing the Enigma
Crucial to understanding enzymes is knowing that they're involved in every aspect of every living thing. That said, science has discovered that the human body recognizes approximately 3,000 different types of enzymes, and different types of cells utilize different enzymes. As overwhelming as this might seem, the good news is that all enzymes have a single, defining factor in common-their function: "The most scientific description of enzymes that still remains understandable is that they're a group of protein molecules categorized as biocatalysts, which literally means they're responsible for either beginning a cellular action or causing a reaction to speed up," offers Christine Heathman, GlyMed Plus, Spanish, Fork, Utah. "Perhaps one of the easiest ways to understand how enzymes work is to consider how our digestion process breaks down food particles such as proteins, carbohydrates and fats to allow the body to absorb the nutrients necessary to build and fuel the new cells that eventually different ate into our various organs and tissues."

When dealing with something so complex, viewing it through a variety of templates and perspectives helps refine our understanding. Howard Murad. M.D., dermatologist, co-author of The Murad Method, (St. Martin's Press) and founder of the Murad skin care product line and the Murad Medical Spa in El Segundo, California, offers an explanation of enzymes by comparing them to other chemical means of controlling keratinocytes. "Dead skin cells-or keratinocytes-are attached to each other by lipids, and are positively and negatively charged; AHAs combine with these structural lipids, dissolving them so that the dead cells break away. Retinoids, which are derivatives of vitamin A, work inside the cell to normalize the cell's production of keratinocytes.

Enzymes work by digesting the keratinocytes-lipid and all." Dieter Kuster, Ph.D., CEO and senior chemist, CA Botana, San Diego, says the mere fact that enzymes serve as cellular catalysts for thousands of biological functions explains why they're both safe to use and effective in anti-aging skin care. "Considered to be a biological response modifier, enzymes are capable of effecting changes in the appearance of the skin such as wrinkle reduction and a healthier glow. They also act as protectants, capturing free radicals and preventing damage to the skin caused by environmental pollution, smoking, bacteria, sunlight and other harmful factors."

Origin & Activity
The enzymes used in skin care are categorized as proteases; proteases are often referred to as being proteolytic, an adjective that calls to attention their specific action of breaking down proteins-in this case, keratin. Incidentally, proteolytic enzymes can be harvested from a range of sources. "Since enzymes are created and produced through different fermentation processes, we find them in fruits, vegetables, marine life and animals," explains Kuster. And, depending on the source, an enzyme will, in addition to its proteolytic action, impart activity unique to itself. The good news is, these extra biological activities are always beneficial. Kuster points out that this is because they're such a basic biological element; in other words, the body recognizes them and accepts them. Because enzymes are found in every living thing, the majority can be simply separated into two groups.

Botanical.
"Every organism has numerous proteases, so in theory they can be isolated from bacteria, fungi, plants or animals," says Christine Cowheard, A Natural Difference, Cooper City, Florida. "But the ones most commonly used in skin care are papain, from papaya; bromelain, from pineapple; and pumpkin protease. Because proteases break the bonds between specific amino acids, proteases from different sources will vary not only in their optimum pH and temperature tolerance, but also according to which amino acid bonds they break. I believe that the reason papain and bromelain are so commonly used in skin care formulations is because they have been shown to be more stable than others."

Heathman agrees, saying that bromelain is especially favored for its ability to purge and detoxify.

"What has changed dramatically in regard to enzymes is the discovery of many nutrients inherent to enzymes of plant sources," says Rhonda Allison, Rhonda Allison Skin Therapy, Dallas. "I like to work with enzymes that break down the skin while building it up. For example, there are fruit and vegetable enzymes that have naturally occurring antioxidants, vitamins and minerals- even low-level AHAs." She cites pumpkin as having the highest percentage of vitamin A and beta carotene of all the vegetable sources, while also carrying with it zinc and salicylic acid. Red fruits and vegetables have their own signature cocktail of nutrients. "Tomato has lots of the antioxidant lycopene, in addition to naturally occurring lactic and salicylic acids. Other sources of similar benefit would be cherry, pomegranate, red grape seed extract and red wine," says Allison. And then there's the protease derived from 100% pure cultured sour milk. "Lactose enzyme has markedly high enzymatic properties in the digestion of skin cells, yet is gentle and is famous for leaving skin glowing for days." The Rhonda Allison line also includes an enzyme product derived from Italian herbs-rosemary, thyme and oregano--and a product formulated with enzymes from mango and peach.

Animal.
"We use only porcine enzyme, which is enzyme that comes from the pancreas of a hog," says Scott Sims, Halina-Andre, Austin, Texas. A unique property of pancreatic enzymes is that their activity can be controlled by altering the pH of the skin. "Using a prepping solution, we first raise the pH of the skin to above 8.0; this softens the skin and creates a perfect environment for the enzymes to work. The product is applied and remains on the skin for between 10 and 20 minutes; after it's removed, a toner is used to bring the pH of the skin back to normal, which would be about 4.5 to 5.0. The main purpose of the toner is to stop any further enzyme activity." According to Sims, elements that activate pancreatic enzyme include water, warmth and a pH above 8.0. Another source of pancreatic enzyme that's used in skin care comes from North Atlantic cod. "Our enzyme products were developed from research into wound healing using proteolytic enzymes, which showed that the pancreatic enzyme from North Atlantic cod is especially active in treating inflammation," says Thor Johannsson, Penzim, Assonet, Massachusetts. "Specifically, it was shown to cleave extra cellular proteins such as interleukin 1, tumor necrosis factor alpha and other cytokines associated with the inflammatory process, as well as bacterial toxins and other undesirable cellular substances. So it became apparent that because of these activities, pancreatic cod enzyme would be useful in skin care." Keeping in mind that many experts tout inflammation as a major precursor to the signs of aging, it follows that pancreatic cod proteases would show esthetic value especially for skin in need of soothing, calming and healing.

Miscellaneous.
Commonly formulated into skin care products, superoxide dismutase is an enzymatic antioxidant found in a range of life forms including anaerobic bacteria, fungi, green peas and-wheat germ. SOD is produced naturally in the human body and other animal life, and research has shown that species with the highest amounts of SOD have the longest life spans. Its main function is to protect oxygen-metabolizing cells against harmful effects of free radicals. "SOD is a particularly stable" enzyme, and it's used in skin care products for its antioxidant activity," says Cowheard. "It works to control oxygen toxicity by converting the superoxide radical to less dangerous forms."

Knowing the inherent differences that set apart one enzyme from another allows you to customize your in-spa treatments for enhanced, targeted: results. Because enzymes aren't as stable as some other actives you're familiar with, many come packaged in forms that must be activated before they're used. This ensures their freshness and efficacy, and increases their shelf life.

"We package our enzymes in hermetically sealed, single-dose packettes," says Murad, who uses fruit enzymes in his product line. Each dose consists of two packettes--a gel and a powder that are mixed at the time of application.

"Our porcine pancreatic enzyme is packaged in a powder form, which is activated when you add water," says Sims, who recommends monthly professional treatments. "Packaging it this way gives it an indefinite shelf life, but more importantly, it allows the esthetician to really customize her services according to the client's skin care needs. For instance, mixing the product at the time of application allows you to blend in herbs such as chamomile for sensitive skin or sage and thyme for acneic skin, because of their astringent properties. Other nutritives that can be added include alfalfa, a natural source of vitamins C, D, E and K; and oats, which are high in soothing beta glucans."
Combining actives is one more way to manipulate the results of a service.
"Our professional treatments combine enzymes with lactic acid, which we use in variable amounts to adjust the strength of the formula," says Sonya Dakar, Sonya Dakar The Problem Skin Specialists, Los Angeles. "Of course, we take into account the condition of the client's skin, but generally we put a client on a monthly schedule, and then titrate the lactic acid so that her skin can acclimate as the treatment gets stronger; and the stronger it is, the deeper it penetrates. I also like to mix in nutritives; examples would be vitamins A and E, minerals, herbs and botanicals."

Allison will use different enzymes at different steps during the same facial. "For professional treatments, I'll start with an enzyme to exfoliate, thereby partially breaking down the barrier so that nutritive ingredients are able to penetrate more easily and effectively. I use a layering method to do this. And many times I'll finish with a different enzyme that has naturally occurring nutritive properties to give the skin a head start on rebuilding."

As science and technology continue to increase our arsenal of treatment options, the successful spa professional will recognize that delivering results-driven skin care will not be an issue of choosing which products, ingredients and modalities to use, but rather in knowing how to incorporate them into a comprehensive treatment menu.
"It's all about 'designer' skin care, says Allison. Having an array of enzymes at your fingertips--each imparting its own, unique activities in addition to its basic enzymatic function-allows you to create specialized treatments to accommodate any client's skin care needs." .

Lisa Randazzo is DAYSPA's special projects editor.