Biological activities of green coffee nanoemulsions evaluated through alternative methods: MTT, cellular proliferation, and HET-CAM assays

Green coffee (Coffea arabica) has been widely explored by the cosmetic industry for its beneficial properties to the skin. The oil from coffee beans helps in hydration by retaining the lipids of the stratum corneum forming a barrier to the water in the skin, also preventing the aging. The green coffee paste also has positive implications in the development of cosmetic products with high biological activity, i.e., anti bacterial, antioxidant, proliferative, and aiding skin healing. This study aims to explore the synergistic effects of coffee constituents by investigating green coffee nanoemulsions. The evaluation will focus on their impact on cell proliferation, viability, as well as the potential risk of eye irritation. The findings will contribute to establishing the safety and efficacy criteria necessary for incorporating these nanoemulsions into cosmetic products. The nanoemulsions were approximately 200 nm in size, with monodispersive characteristics, and negative charged. In vitro biological tests showed that green coffee nanoemulsions had low cytotoxicity, stimulate cell proliferation and did not show eye irritation by the alternative methods to animal use that have been tested. The study demonstrated promising potential, but further research is necessary for its practical incorporation into the industry.