j. Cosmet. Sci., 51, 27-36 (January/February 2000) Antiwrinkle and skin-moisturizing effects of a mineral-algal-botanical complex Z. MA'OR, G. MESHULAM-SIMON, S. YEHUDA, and J.A. GAVRIELI, Dead Sea Laboratories Ltd., Dead Sea 86983 (Z.M., S.Y.), and IMI (Tami), Institute for R&D Ltd., Haifa 26111 (G. M. -S., J.A.G.), Israel. Accepted j3r publication December 15, 1999. Synopsis Tests were carried out to compare the skin-smoothing and moisturizing effects of two cosmetic preparations, following two applications a day over a period of four weeks. The skin roughness parameter, Rz, was determined at the beginning and end of the study. The skin hydration was evaluated eight and twelve hours after cream application. At the end of four weeks, the cream enriched with 5% of Triple D Complex TM, composed of Dead Sea Mineral Skin Osmoter TM, Dunaliella salina algae extract and desert plants, had caused an average reduction of the skin roughness parameter by 43%. This effect was almost twice the improvement that was observed when a control cream was tested. From skin hydration results it can be concluded that the Triple D Complex TM may also be considered as an active moisturizing agent. The role of Dunaliella salina biomass enriched with Dead Sea minerals, as an active component of the complex, was examined separately. Several parameters that may affect the mineral biosorption and desorption were evaluated. The relatively low biosorption of calcium and magnesium into the algal biomass and the minimal tendency to release minerals from the biomass at the pH of skin leads to the conclusion that the role of these algae as a vehicle for the tested elements is limited. Similar results in skin smoothing, obtained in two distinct studies, using Dead Sea Mineral Skin Osmoter TM and Triple D Complex TM, suggest that Dead Sea minerals play a major role in the proven antiwrinkle effect. INTRODUCTION Chemists all over the world are eagerly searching for new active agents to benefit the skin health and beauty industries. The global trend toward using natural ingredients is focused on components that are extracted from the botanical world, and from marine algae, commonly known as seaweeds, which have been widely used over the centuries for their nutritional and therapeutic properties. Seaweed is one of the richest natural sources of vitamins and minerals, possessing sea mineral salts in high concentrations and also trace elements. It has been demonstrated that similar minerals from the Dead Sea can act as agents in the reduction of skin roughness, and have a beneficial effect on the natural moisturizing factor, NMF (1-3). It has been shown in several publications that skin may alter its metabolism and its inner enzymatic activities when exposed to a graded concentration of minerals, especially 27

28 JOURNAL OF COSMETIC SCIENCE calcium, magnesium, and potassium ions. The mode of physicochemical action of the minerals is not yet fully understood (4,5). Stabilization difficulties, caused by a high electrolyte concentration, are considered as drawbacks in formulating minerals in cosmetic preparations (6). Using mineral carriers as vehicles may enable a better stabilization of the formulations, thus slowing and sustaining the mineral release to the skin surface. Mineral carriers may contribute to the production of mineral-rich long-lasting products. Certain types of microbial biomass can retain relatively high quantities of metal ions by passive sorption and/or complexation. This phenomenon is generally known as biosorp- tion (7). Micro algae from hypersaline habitats have adopted some unique metabolic pathways that enable their survival under relatively high osmotic pressures (8). The green alga D•naliella salina from the order Volvocales/Chlorophyceae, isolated from diluted Dead Sea water, can accumulate high contents of glycerol and [3-carotene (9,10). This alga also contains vitamins such as thiamine, pyridoxine, riboflavin, vitamin E, and biotin. Its beneficial effects, including immunological enhancement of topical applica- tions of [3-carotene and other free radical scavengers, have been reported previously (11). Some plant extracts are recognized as folkloric remedies. Some of these have proven pharmacological activity others have pretentious sophisticated claims, but are ineffec- tive (12). A combination of natural ingredients and blended components from the various sources that were mentioned above may lead to the development of a unique, active composition with potentially synergistically beneficial effects. Meanwhile, the increasing public de- mand for scientific proof of cosmetic performance claims, as well as new legislation, has encouraged the cosmetics industry to submit studies demonstrating the activity of their preparations. Acceptable testimonies to support a claimed effect for bioactivity can take the form of a published scientific or clinical study, consumer evaluation, professional observations, and instrumental analysis. Results from in vitro tests, mainly cell-culture models, have been used recently to support the bioactivity of some cosmetics (13). In a previous article we have reported that the addition of 1% of Mineral Skin Os- moter TM to a control gel contributed to a significant skin smoothing effect (1). The role of minerals in improving skin roughness and hydration was demonstrated. The aim of the prsent study was to evaluate the effect on the skin of a cosmetic cream with 5 % of a mineral-algal-botanical complex (Triple D ComplexTM). The assumption that Du- naliella salina algae, as a part of this unique complex, would serve as an adequate vehicle and a bio-available source for minerals delivered to skin was also examined. The en- richment of Dunaliella biomass with Dead Sea minerals, and several parameters that could affect mineral biosorption and desorption, were studied. MATERIALS AND METHODS MINERAL-ALGAL-BOTANICAL COMPLEX (TRIPLE D COMPLEX TM) PREPARATION A unique composition, the Triple D Complex TM was composed of three elements: Dead Sea Mineral Skin Osmoter TM, Dunaliella salina algae extract, and desert plant extracts (14). Dead Sea Mineral Skin Osmoter TM, is called "sea salt" in the US and INCI-listed as "Maris Sal & Aqua" (supplied by Dead Sea Laboratories Ltd.) Dunaliella salina algae