Exploring the antioxidant potentiality of two food by-products into a topical cream: stability, in vitro and in vivo evaluation

Abstract

Context: Coffee silverskin (CS), a food by-product of the coffee roasting industry, has been studied as an active ingredient for skin care products due to its high potential of antioxidant activity and low cytotoxicity. Another food waste used as ingredient with promising characteristics is obtained from Medicago sativa (MS), which antioxidants and isoflavones content is high.

Objective: The aim of this study is to evaluate and characterize a new body formulation containing two food by-products extracts.

Materials and methods: Different parameters (such as pH, rheological behavior, color, antioxidant content and microbiological analysis) of a body cream formulation containing by-products (CSMS) and a formulation without extracts (F) were evaluated under a stability study during 180 days at different temperatures. Moreover, the in vitro cell toxicity and the in vivo skin safety and protective effects were also assessed.

Results: Formulation showed stable physical properties and antioxidant activity during 180 days of storage. In vitro toxicity was screened in two skin cell lines (fibroblasts and keratinocytes) and any toxicity was reported. The in vivo test carried out showed that, with respect to irritant effects, CSMS formulation can be regarded as safe for topical application and the skin hydratation improved after 30 days of its use. Also, considering the consumer acceptance, more than 90% of volunteers classified it as very pleasant.

Conclusions: CSMS formulation is stable and safe for topical use as no adverse and/or side effects were observed during the application period of testing, improving skin protective properties.

• Coffee silverskin
• cosmetics
• food by-products
• in vitro toxicity
• Medicago sativa
• skin irritation
• skin biophysical techniques
• stability

Acknowledgements

The authors wish to thank to BICAFÉ and DS Produtos Químicos for providing, respectively, CS samples and raw materials for body formulation development and production. Also, the authors want to thanks to LabFit – Health Products Research and Development (for microbiological analysis support) and greatly acknowledge all volunteers.

Declaration of interest

Francisca Rodrigues is thankful to Foundation for Science and Technology (Portugal) for the PhD grant SFRH/BDE/51385/2011 financed by POPH-QREN and subsidized by European Science Foundation. This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Foundation for Science and Technology) through project Pest-C/EQB/LA0006/2013. The work also received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07–0124-FEDER-000069. To all financing sources the authors are greatly indebted. The authors declare that there are no conflicts of interest.