PREPARATION AND EVALUATION OF CREAM MASK 453 respectively, 20%, 15.2%, and 16.6% of DW red algae such as K. alvarezii and K. stria- tum were mainly rich in carrageenans (up to 45.8% of DW in K. alvarezii), whereas G. tenuistipitata and G. bailiniae presented mainly agar (up to 34.6% of DW) brown algae including S. oligocystum, S. crassifolium, and S. denticarpum were mainly rich in alginate (up to 30.9% of DW in S. crassifolium). These compounds have been reported that they have high antioxidant capacity (28). Like sulfated polysaccharides, pigments such as chlorophyll and carotenoid also represent a safe alternative for the cosmetics industry (29,30). Notably, carotenoids have antioxi- dant and anti-infl ammatory properties that contribute to skin photo-protection through inhibition of Ultraviolet A-induced reactive oxygen species toxicity and enter in the formulation of many sunscreens (31). For the major photosynthetic pigments, the total chlorophyll contents of 10 studied seaweed species ranged from 117.19 to 790.12 μg/g of fresh weight (FW) and the carotenoid content ranged from 19.2 to 86.20 μg/g of FW. The highest chlorophyll and carotenoid contents were observed in C. lentillifera, with values of 790.12 μg/g of FW and 86.20 μg/g of FW, respectively. C. lentillifera also pos- sessed the highest vitamin A and vitamin E (2.87 and 19.8 μg/g of FW, respectively), whereas U. reticulata exhibited the highest value of vitamin C (150.12 μg/g of FW). Antioxidants such as sulfated polysaccharides, pigments, and vitamins can help to main- tain the organoleptic properties of cosmetic products by inhibiting lipid oxidation, thus avoiding changes in appearance, odor, and fl avor (32). According to defi ned standards of biochemical compositions as follows: protein content of 10% DW, lipid- 0.8% DW, polysaccharides- 44% DW carotenoid, and chlorophyll contents-30, 205 μg/g of FW and vitamin E, C contents-0.4, 85.68 μg/g of FW, we selected four potential species including C. lentillifera, S. crassifolium, U. reticulata, and K. alvarezii to develop cosmetic products with ingredients from seaweeds. In addition, previously, we reported that Sargassum swartzii and U. reticulata collected in Vietnam have potent analgesic and anti-infl ammatory effects, without any serious toxic effect at highest possible doses in animal model (9). Our previous study also showed that either dried powder of the U. reticulata or the methanol extract of S. swartzii has hypolipidemic effects in mice (8). They may be useful as food to prevent hyperlipidemia. Moreover, presently, C. lentillifera and K. alvarezii are cultivated at a commercial scale in Vietnam, whereas S. crassifolium and U. reticulata have high natural productivities. For these reasons, they are suitable as raw materials for cosmetics. According to Burtin (33), seaweeds must meet safety regulations in terms of toxicological criteria. In France, the quality criteria applied to edible seaweeds revealed the standards as upper limit for arsenic less than 3 ppm, 5 ppm for lead, 0.5 ppm for cadmium, and 0.1 ppm for mercury. Thus, those species were further studied for heavy metal content. The contents of heavy metals in four selected seaweed species are shown in Table II. The ob- tained results indicated that the heavy metal concentration in the selected seaweeds was within the tolerable value reported as the quality criteria for cosmetic. BIOACTIVITY OF SEAWEED EXTRACTS Effect of seaweed extracts on cell proliferation activity. Aging results mainly in the loss of dermal collagen and the accumulation of unorganized collagen and elastin fi bers in the dermis. Fibroblasts play the key role in wrinkle formation because they produce basic structural

JOURNAL OF COSMETIC SCIENCE 454 skin substances: collagen, elastin, and hyaluronic acid. During the aging process, the pro- liferative and metabolic activity of fi broblasts decreases, the fi bers’ functions are impaired, and their structure becomes modifi ed and then destroyed (34). Therefore, the capability of seaweed extracts and their mixture to stimulate proliferation of skin cells was investi- gated at a concentration of 3 and 5 mg/mL. As shown in Figure 1A, each seaweed extract or their mixture signifi cantly stimulated the proliferation of fi broblasts by approximately 10–57%, in a dose-dependent manner. Notably, the highest cell proliferation was observed in cells stimulated 5 mg/mL of the mixture. Similar but stronger trends were observed in cells stimulated sodium lauryl sulfate which have been reported for fi broblast prolifera- tion (35). These fi ndings suggest that water extract of seaweeds might be useful in anti- aging treatment. Evaluation of moisture retention. Proper hydration of skin is crucial for healthy skin func- tion, and moisturizers are essential components of basic skin care. The in vitro moisture retention property of seaweed extracts was examined gravimetrically and compared with Figure 1. The stimulation of cell proliferation by seaweed extracts (A). Moisture retentions of seaweed ex- tract (B). Inhibitor effects of seaweed extracts on the activity of mushroom tyrokinase (C). Results are ex- pressed as mean ± SEM (the standard error of the mean) of three separate experiments. *p 0.05, **p 0.01, versus control of each group. Table II Heavy Metal Content of Four Selected Seaweed Species No Samples Pb (ppm) Cd (ppm) As (ppm) Hg (ppm) 1 Caulerpa lentillifera 0.390 Nd 0.74 Nd 2 Ulva reticulata 0.455 0.045 2.008 0.017 3 Sargassum crassifolium 0.542 0.078 1.958 Nd 4 Kappaphycus alvarezii 0.425 0.098 1.002 0.020 Nd: not detected.