displayed a significant moisturizing effect, as determined via use of a CorneometerÂ® CM 825 (Courage + Khazaka Electronic GmbH, Germany), which was present up to two weeks after discontinuing treatment.20 Effective moisturizing potential is important to the photoaged population, as many of these patients will present with xerosis and an impaired skin barrier. A safe, tolerable, natural moisturizing agent with low irritant potential makes for an excellent product to rapidly improve skin appearance.
Acai is a berry that grows on the acai palm tree (Euterpe oleracea). An evidence-based systematic review of acai by the Natural Standard Research Collaboration, which summarizes efficacy data via a validated, reproducible grading algorithm, concluded that acai is a potent antioxidant.21 When acai polyphenolics were applied to HL-60 leukemia cancer cells, cell proliferation decreased.22 The antioxidant capability of acai berry is believed to be greater than that of other berries. However, topical use of this supplement is challenging given the risk of skin staining at high concentrations.7 Perhaps for this reason, there is a paucity of clinical research on the use of acai berry for the treatment and prevention of photoaging. A clinical trial evaluating the use of a dietary supplement containing pomegranate, apple, and acai is seeking to evaluate erythema inhibition, antioxidant concentration, skin hydration, skin firmness, and skin texture in study subjects as compared to placebo. The study has closed but the results are not yet available.23
Soy extracts are found in many cosmetic products. Lipids, lecithins, and phytosterols enhance the normal skin barrier, while isoflavones impart an antioxidant effect. A study of hairless mice examined the effects of a soy isoflavone extract from soybean cake composed of daidzein, genistein, glycitein, acetyldaidzin, acetylgenistin, and acetylglycitin. Extract-treated mice and untreated mice were exposed to UVB radiation. Treated mice showed a decrease in UVB-induced death of keratinocytes and reduced erythema. The skin of extract-treated mice also displayed less transepidermal water loss and less apparent wrinkles. Many of these results were deemed secondary to reduced oxidative stress.24
Serine protease inhibitors such as soybean trypsin inhibitor (STI) and Bowman-Birk protease inhibitor (BBI) play a role in pigment development. Wallo et al tested a formulation containing nondenatured STI and BBI (as heat can inactivate these protease inhibitors) on 68 females with Fitzpatrick skin types I to III. All patients had moderately rough, blotchy, dull skin, mottled hyperpigmentation and lentigines at baseline. The women were randomly selected to apply either the active moisturizer or the vehicle daily for 12 weeks. Both formulations contained SPF 30. Although both groups showed improvement from baseline, the active moisturizer group exhibited enhanced performance (P < 0.05) in improvement of overall texture, blotchiness, dullness, fine lines, overall tone, and overall appearance.25
The use of soy is controversial among consumers, who worry about an increased risk of endometrial and breast cancer development. A recent Cochrane Review of the use of oral phytoestrogens for menopausal vasomotor symptoms found that phytoestrogens were not associated with an increased risk of endometrial or breast cancer when used for up two years. Unlike hormone replacement therapy, phytoestrogens did not have an estrogen agonistic effect on the endometrium. Longterm safety studies have not been conducted.26
Coffee berry is the fruit of the coffee plant (Coffee Arabica). It contains polyphenols, including chlorogenic acid, anthocyanins, quinic acid, and ferulic acid.16 Polyphenols are believed to impart antioxidant as well as anti-inflammatory properties.
One patented formulation of coffee berry appears to have antioxidant capacity that rivals green tea extract. In a clinic trial of this specific formulation, patients treated actinic damage with a 0.1% cleanser, a 1% day cream (containing also 7.5% octinate and 4% oxybenzone), and a 1% night cream. Two-thirds of the patients applied the products to their entire face, showing statistically significant improvement in fine lines, wrinkles, pigmentation, and overall appearance compared to baseline. One-third of the patients applied the product to only half of their face, showing statistically significant improvement in fine lines, wrinkles, pigmentation, and overall appearance compared to the vehicletreated half of the face.27
Patients are highly motivated to treat and prevent photoaging, and may inquire as to the availability of natural ingredients to treat rhytides, dyschromia, and actinic damage. As dermatologists, we can provide guidance as to which ingredients may be of benefit based on available scientific evidence. Mushrooms, feverfew, green tea, licorice, olive oil, soy, and coffee berry all display antioxidant properties. They are among the most scientifically sound natural ingredients available to consumers. Importantly, we can also help direct patient to those proprietary formulations that have undergone clinical testing and demonstrate safety and efficacy. Just because a product label lists an ingredient does not mean that ingredient is stable or active once it reaches the skin. It is important to remind patients that the efficacy of a product relies on the stability of the ingredients, their ability to penetrate the skin, and their capability to act in vivo. This is a very exciting area, and as consumer interest in natural ingredients continues to grow, the science behind these ingredients grows stronger each year.
The authors would like to acknowledge Awadh M. Alamri MD, Jayne Bird MD, and Brooke Walls DO, for their research and contribution to the manuscript.