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Recent Advances in Slimming Treatments
By Karen A. Costa-Strachan, PhD
Posted: August 22, 2007, from the September 2007 issue of Skin Inc. magazine.
Popular places on the body for contouring treatments include the hips, thighs, buttocks and abdomen. One reason for this is that the hips, thighs and buttocks are areas particularly prone to cellulite. Cellulite is a term used to define the puckered, dimpled or “orange peel”-like appearance of the skin often seen in these areas of the body. Cellulite typically begins to develop during or after puberty, so it is thought that estrogen plays a role in its development.1
Cellulite can manifest in women of all ages, races and body weights. Although weight gain can worsen the appearance of cellulite, it is noteworthy that even slender women can suffer from the appearance of cellulite.2 ,3 Thus, it is not surprising that the hips, thighs and buttocks are sites that are also popular targets for slimming treatment products.
Skin structure considerations
The outer layer of the skin reflects activity beneath its surface, especially when structural changes are occurring. Therefore, to best understand how to target slimming formulations to these areas, it is worthwhile to understand a bit more about the underlying anatomy.
The skin is composed of the epidermis and the dermis. Underlying the dermis is the hypodermis, or subcutaneous fat layer. The subcutaneous fat layer can be thought of as being composed of two sub-layers. These two sub-layers include the deeper localized fat deposits and the more superficial compartmentalized layer of fat.
Localized fat deposits typically are the targets of liposuction. Cellulite appears to originate in the fat layer where structural compartmentalization of adipose, or fat tissue, is predominant.4-6 Small, upright chambers are encircled and separated by vertical bands of connective tissue (CT), referred to as septa. The compartments are anchored to the dermis above and the tissue below. Overall, the appearance of the compartments can be described as somewhat honeycomb.
When the fat cells in these chambers become enlarged and fluid accumulates there, the chambers begin to bulge, pressing against the septa. This bulging phenomenon of the septa contributes toward the appearance of dimples and bumps on the surface of the skin in cellulite.6 With age and sun damage, the septa, composed principally of collagen, can become further weakened and thickened, resulting in shrinkage.6-8 As the septa shrink and pull on the underlying anchors of the chambers, this also can contribute to the indentations seen on the surface of the skin in cellulite. 6-8
Another hypothesis regarding cellulite notes that an inflammatory process caused by decreased circulation may also be involved. It is believed that the early structural changes leading to cellulite formation are the result of decreased circulation, which itself is the direct result of deterioration of the dermal blood vessels—especially a loss of the capillary networks.8 The loss of the capillary networks has been hypothesized to be caused by engorged fat-storing cells, called adipocytes, joining together and inhibiting venous return.
Clearly, there are a number of targets that slimming treatments can address. These areas include: enhancing the removal of fluid buildup by improving microcirculation to the areas in question; strengthening the CT while protecting it from further degradation caused by inflammation and the subsequent release of matrix metalloproteinases (MMPs), which are capable of degrading all kinds of extracellular matrix proteins; and targeting the adipose tissue via stimulation of adipocyte cell metabolism, thermogenesis or some other mechanism to decrease adipocyte contents—lipolysis, or the breaking down of fat stored in cells. Traditional and newer approaches to slimming treatments use a number of ingredients to achieve such ends, described below.9–14
Enhancing fluid build-up, improving microcirculation. A number of ingredients in slimming treatments may help to enhance fluid buildup and improve microcirculation. Rutin is a citrus flavonoid glycoside found in buckwheat, the leaves and petioles of the Rheum species, and the fruit of the Brazilian Fava D’Anta tree. Rutin possesses both anti-adipogenic and capillary-strengthening properties that can be beneficial to the reduction of cellulite.9-10
Bilberry extract has been noted to have effects on new capillary formation, as well as enhancing microcirculation.11-12 Citrus bioflavanoids from lemons, grapefruits and oranges and fruit bioflavanoids such as hesperidin, eriocitrin and flavonones from grapes, plums, apricots and cherries possess the ability to both strengthen the capillaries and regulate their permeability.13
Ginkgo biloba contains flavanoids that have been shown to have vasokinetic as well as lipolytic effects.14
Several reviews 15-19 describe botanical extracts used in cellulite treatments, some of which are briefly mentioned here.
Uva ursi, a herb derived from bearberry, juniper berries, Elymus repens (couch grass) and Agathosma betulina or A. crenultata (buchu), have been associated with loss of excess fluids in tissues, leading to improvements in water retention.
Horsechestnut is claimed to strengthen venous walls, improve circulation and target edema. Aescin, the active constituent of horsechestnut extract, has the added ability to block elastase, and hence help to preserve elastin, an important structural connective tissue responsible for blood vessel integrity and tone.
Hawthorne berry has been shown to improve blood flow, while horsetail extract has been associated with strengthening the walls of arteries and veins. Ginseng and angelica extract are known microcirculation boosters. Butcher’s broom extract (Ruscus aculeatus) contains ruscogenin and neoruscogenin, both known to strengthen veins. Finally, xanthine derivatives, such as gotu kola as noted later in this article, can also find a presence in slimming treatment formulations for their diuretic effects.
Protecting, strengthening connective tissue. The integrity of the CT in capillaries and veins is vital for their proper functioning. Likewise, the integrity of the CT of the septa in the hypodermis is important. Breakdown of the CT in the vessels leads to capillary permeability and edema, while breakdown of the CT in the septa causes the compartments of adipose to become more fragile.20 Both the blood vessels and the septa in the hypodermis play a role in the development of cellulite.20 All connective tissue, including collagen, elastin, fibronectin and various glycosaminoglycans (GAGs), can be adversely affected by matrix metalloproteinases (MMPs).
MMPs are often released by cells in response to inflammation. Examples of MMPs include various collagenases and elastases. One goal of cellulite-specific slimming formulations is to provide ingredients that target both inflammation and MMP deactivation, as well as ingredients to directly strengthen the CT. Ingredients such as retinoic acid, retinols, vitamin A derivatives and vitamin C have shown strengthening effects on CT either by direct stimulation of cells to produce healthy collagen or elastin, or by playing a supporting role in the biosynthesis of the connective tissue.17, 20
Antioxidants in a formulation can also help to alleviate the inflammation and resultant release of MMPs that target the destruction of CT.21 The choice of antioxidants is extensive and includes ingredients such as: grape seed extract; green and white tea extracts; vitamins C and E; coenzyme Q10; genistein; lycopene; carotenoids, such as beta-carotene and lutein; pomegranate extract; alpha lipoic acid; reservatrol; and pine bark extract. Other potential sources of antioxidants include spices such as garlic, onion, turmeric, rosemary, sage, thyme and oregano.