Rice bran extract offers numerous benefits
Nancy E. Kinkade Ph.D. – Eastman Chemical Company
The use of natural ingredients is an important trend shaping the personal care market. Consumers are enticed by multicultural, multi-benefit products that promise perceivable benefits to enhance their physical beauty. For cosmetic and personal care companies, new opportunities proliferate at the boundaries of traditional market segments where the one trillion US $ wellness market continues to expand at a rapid rate.
Suppliers, manufacturers and brand owners alike are conducting research on products and ingredients that meet consumer demand for natural products offering benefits. One such successful example of this is Eastman Chemical Company, which, nearly 10 years ago, began research on the benefits of natural rice bran derived products.
In 2006, Eastman introduced NutriLayer Phytolipids to the international personal care industry. NutriLayer is a premium, natural ingredient and is extracted from rice bran from nongenetically modified (non-GM) rice under cGMP conditions. Additionally, the NutriLayer (the extract) contains many beneficial, naturally occurring ingredients including rice bran wax, squalene and phytosterols, as well as tocopherols and tocotrienol isomers. These components provide many potential benefits including anti-oxidation, moisturisation, barrier, and skin soothing and smoothing. NutriLayer is an absorption base which can take-up three times its weight in water. The extract offers a vegetable sourced alternative to petroleum and animal derived absorption bases.
Recommended for topical skin and face creams, sun screens and lip care, this extremely powerful, concentrated product allows cosmetic makers to obtain multiple benefits from one natural ingredient. To better understand the tangible benefits of the extract on consumers, Eastman’s laboratories formulated two prototype moisturising creams with NutriLayer at 1%and 5% concentrations. This article discusses the results of two studies using the formulated creams containing the extract and the technical work conducted to explore the anti-oxidant properties of the two NutriLayer creams.
Scientific analysis – a look at the data
Over a few months, Eastman completed both phases of its research. The technical phase provided quantifiable data supporting the anti-oxidant properties of the extract and the two-week and twelveweek studies on consumers provided support for its moisturising abilities.
Eastman investigated the free radical scavenging and antioxidant properties of the extract using two common in vitro tests: a DPPH (diphenyl picrylhydrazyl) free radical method and a fatty acid assay method. The DPPH method measures the Oxygen Radical Absorbance Capacity (ORAC), i.e., the free radical scavenging ability of the test material. Higher ORAC values indicate a greater capacity for neutralising free radicals. The 1% and 5% NutriLayer creams are three and eight times, respectively, more effective at scavenging free radicals than Trolox 1 – a vitamin E derivative with good anti-oxidant activity and an ORAC value of 1.
The outcome of these tests showed that the extract is able to scavenge free radicals. Next, Eastman researchers wanted to determine if the extract also protects lipids from oxidation. The second test using linoleic acid as a model fatty acid and hemoglobin as a catalyst reveals that both extract creams are effective at inhibiting lipid oxidation. The results shown in the graph on the previous page, demonstrate the concentration dependant antioxidant capabilities of the extract containing creams.
As the results of these two studies proved promising, Eastman commissioned a research study to investigate the effect of the 1% and 5% extract creams on the formation of Reactive Oxygen Species (ROS) in MatTek EpiDerm skin models after illumination with UVA and UVB radiation. Epiderm tissue is a multilayered, highly differentiated model of the human epidermis. It consists of normal humanderived keratinocytes and contains in vivolike lipid profiles. The presence of ROS can contribute to the appearance of wrinkles.
Reducing or destroying ROS can help prevent or slow the visible signs of ageing. The study uses a cutting-edge technology called Two-Photon Fluorescence Microscopy, which evaluates the tissue at various depths. The tissues are treated with a chemical which reacts with ROS to form a fluorescent analogue. The images above demonstrate the difference in fluorescence of a placebo treated and an extract treated sample at four different depths into the skin tissue. The placebo and NutriLayer cream formulations are identical, except in the placebo, NutriLayer is replaced with water. The colour and intensity are indicative of the amount of reactive oxygen species (ROS) present in the tissue.
Fluorescence microscopy reveals that both concentrations of the extract creams reduce the concentration of ROS present in the epidermis after exposure to UVA and UVB. The study results demonstrate that the 5% extract cream significantly reduces ROS in the basal layer and 50% of the free radicals deep within the epidermis were destroyed. After the application of the 5% extract cream, the dark blue colour, which represents the absence of ROS in the skin cells, was more apparent than in the placebo-treated tissue sample.
Demonstrated
The Fluorescence Microscopy study demonstrated that the extract could be beneficial in reducing ROS in skin cells. The next study demonstrates the effectiveness of the same creams as compared to the placebo cream, and a US$ 50 jar of commercial day cream from a premium cosmetics manufacturer. Testing consisted of gathering sensory perceptions from subjects for the four creams when applied to the participant’s hands, a one-week use test of two of the four creams by each participant and photographic documentation of the appearance of the crow’s feet areas before and after one week of use.
The participants were 40 volunteers ranging in age from 30 to 60+ years old, with the majority being between the ages 41 to 55. Most of the women in the study had normal, dry or combination skin types and a few had oily skin. The purpose of this study is to determine the sensory and appearance effects of the 1% and 5% NutriLayer creams, a placebo cream, and a US$ 50 commercial cream. The placebo cream is the same formulation as the creams containing the extract, but where the ingredient is replaced with water. Many of the women used some moisturising or anti-ageing products on their face prior to starting the study, but only the test creams were used during the study.
Phase One
The first portion of the study required the women to evaluate the four creams on their hands. First, the women applied the cream and then were asked questions about the creams in terms of absorbency, wetness, silkiness, oiliness and spreadability. Many women rated both extract creams high on spreadability, absorbency and silkiness and low on oiliness and wetness. In fact, the last two factors received close to the highest positive rating.
Next, the women let the cream sit on their hands for two minutes and then were asked to rate the creams again. The women rated the sensory effects on a seven-point descriptive scale. This twominute sensory effect tested for dryness, stickiness, oiliness and silkiness of the skin. Women with dry skin had a particularly positive response, reporting that the cream showed excellent results. In addition to its moist and silky feel, many women in both the dry and oily skin groups said that the cream was very soothing and not too oily or sticky.
Even at this early stage in the efficacy study, NutriLayer in a cream formula was given excellent reviews.
Phase Two
During the second phase of the efficacy study, the women were asked to apply the 1% and 5% creams at home on alternate sides of the face for one week. After using the extract for this short time; many women reported outstanding performance. The formulas containing the extract provided visible reduction in wrinkle appearance and excellent moisturising capabilities.
One woman remarked “NutriLayer is great, my skin is dewier and I have noticed an incredible amount of wrinkle reduction around my eyes and neck.”
Another interesting factor of the home application study was that the extract showed positive results for a variety of skin types. No participants in this study reported an adverse effect on their skin after using the extract regardless of skin type. This includes both the sensitive and oily skin groups. A woman in the oily skin group reported that she was previously unable to use moisturisers at all, because her skin was so oily. The 1% extract cream, however, absorbed easily and moistened her skin.
“I applied the formula at night and loved the results in the morning,” she said. “Normally, when I wake up in the morning, my skin feels very oily, but I didn’t experience that with NutriLayer.”
Eastman will continue to research the effects of the extract on oily skin, as it may be particularly powerful for creams in this area of skin care.
This is a good indication that the extract may be used in the future in a multitude of ways and for many different types of skin. After the results of the hand and oneweek facial evaluations were in, it became evident to Eastman researchers that the 1% extract cream showed the highest probability overall of being preferred by most women. Its light and silky feel was preferred by most women over the highend commercial day cream. The 5% cream also received very favorable comments by many of the women testing it and was in some cases preferred even over the 1% cream. It was very evident that all skin types found beneficial results from the extract creams.
Final Phase
In the last phase of the study, researchers asked each of six women to use either the 1% or 5% extract creams on her face twice daily for twelve consecutive weeks. All three skin types – dry, oily and normal/combination – were represented in this group. For each skin type one woman used the 1% cream and one the 5% cream. The oily skin women both heaped praise on their respective creams and one woman with dry skin said: “My skin hasn’t been nearly as dry and the wrinkle reduction has been maintained as I have used the product.”
The images show the dramatic impact of using the 1% extract cream on one of the subjects.
As indicated by the wrinkle area graph (overleaf), 50% reduction in the appearance of wrinkles observed after 4 weeks. Also, this reduction in wrinkles is maintained through the remaining 8 weeks of the study. The slope of the curve in the graph is of great importance, because it shows that the extract is making a durable and gradual impact on the skin’s appearance unlike other ingredients that reduce the appearance of wrinkles through a masking, or filling effect or by only changing the reflection of light on the skin. This indicates that there is indeed longterm, benefit potential for the extract.
In addition, these trials show clear indications that a 1% extract cream will perform and deliver tangible consumer benefits. It is clear that this natural ingredient, even at low concentration delivers impressive results. The fact that the extract can be used very economically may also be a great benefit to personal care product developers in the future. Future studies
Eastman will conduct future studies with the 1% extract cream to quantify its effect on oily skin by taking sebum measurements. Other expected research directions include the effect of the extract on dry lips and excessively dry and/or compromised skin.
Conclusion
Eastman’s research results show the outstanding capabilities of this product with regard to its antioxidant and antiaging properties. The extract in a cream formula has not only withstood the scrutiny of research teams, but consumers as well. Personal testimonies and scientific research have shown that the extract is an exciting and ground-breaking new advancement in natural skin care ingredients that delivers outstanding short and long term consumer benefits. Reference
1 Trolox is a registered trademark of OXIS International Inc.
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