TAURINE/ALOE VERA FOR BOOSTING ANTI-SKIN IRRITATION EFFECTS 223 (p 0.05) (Figure 8). Topical application of the benchmark product resulted in higher IL-1α levels compared with our prototype formulation containing taurine and aloe ex- tract. Our results are analogous to those demonstrated in the in vitro EpiDerm model (Figure 5) and reveal the applicability of the anti-irritating effects of taurine and aloe extract in vivo. CONCLUSIONS AlCl3 is a strong skin irritant and is known to cause the formation of ROS and induce lipid peroxidation (6,7). The low pH of AlCl3 containing formulations leads to the release of pro-infl ammatory cytokines, chemokines and causes tissue damage. However, the low pH is necessary to maintain the effi cacy of AlCl3. Higher pH environments result in the formation of larger, ineffective aluminum species (19). Therefore, the addition of Figure 5. IL-1α conce ntrations in EpiDerm cell culture media (n = 3) after topical application of AlCl3 products for 1 h. Negative control (NC) was untreated tissue and positive control (PC) was tissue treated with 12% AlCl3 solution without taurine or aloe extract. A commercial 12% AlCl3 antiperspirant product was used as a benchmark product to assess irritancy potential. Prototype 12% AlCl3 product with and without 0.1% taurine and 0.1% aloe extract actives were tested.

JOURNAL OF COSMETIC SCIENCE 224 anti-irritating agents into dermatological vehicles has become necessary to mitigate the contact irritant dermatitis that arises from the usage of antiperspirants containing AlCl3. Our results have revealed the existence of a boost in anti-irritating effects that the taurine and aloe extract blend demonstrate on topical application. We observed that co-treatment with taurine and aloe extract in a PBS solution results in further inhibition of IL-1α pro- duction compared with treatments with only taurine or aloe extract in human epidermis model. EpiDerm tissue treated with 0.1% taurine and 0.1% aloe extract released lower levels of IL-1α compared with tissue treated with only 0.2% taurine or 0.2% aloe extract (Figure 4). IL-1α is a primary cytokine that is constitutively expressed by keratinocytes and plays a major role in the onset of infl ammatory responses in the skin (20). IL-1α re- lease from human epidermal equivalents is commonly measured to predict the irritation potential of consumer products and provides reliable in vivo correlation (21). We next addressed whether the anti-irritating effects of taurine and aloe extract would still be observable in oil in water emulsion formulation containing 12% AlCl3. Our Figure 6. IL-8 concentr ations in EpiDerm cell culture media (n = 3) after topical application of AlCl3 prod- ucts for 1 h. Negative control (NC) was untreated tissue and positive control (PC) was tissue treated with 12% AlCl3 solution without taurine or aloe extract. A commercial 12% AlCl3 antiperspirant product was used as a benchmark product to assess irritancy potential. Prototype 12% AlCl3 product with and without 0.1% taurine and 0.1% aloe extract actives were tested.