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

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: a possible valuable cosmetic ingredient.

CONTEXT: Currently, there is a great tendency in cosmetic area to use natural extracts. Coffee silverskin (CS) is the most abundant solid by-product generated during roasting of coffee processing. OBJECTIVES: To evaluate different CS extracts as promising cosmetic ingredients, regarding antioxidant, antimicrobial, and cytotoxic properties. MATERIALS AND METHODS: Aqueous, hydroalcoholic and ethanolic CS extracts were obtained by an environmentally friendly procedure considering costs and pollution. Extracts were characterized for total phenolic and flavonoid contents (TPC and TFC, respectively), antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), antimicrobial activity expressed as minimal inhibitory concentration (MIC) and cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) and lactate dehydrogenase (LDH) assays in two skin cell lines (fibroblasts and keratinocytes). RESULTS: The TPC of extracts was 18.33-35.25 mg of gallic acid equivalents per g of material on a dry basis (mg GAE/g db). The TFC of extracts was 1.08-2.47 µg cathechin equivalents per g dry material (µg CE/g db). The antioxidant activity was high, with values ranging between 95.95 and 216.40 µmol Fe(2+)/g for aqueous and alcoholic samples, respectively. Preliminary assays for antimicrobial potential showed that extracts display antibacterial activity. The MIC varied from 31.3 to 250 µg/mL for Gram-positive, and from 31.3 to 1000 µg/mL for Gram-negative. Extracts did not affect in vitro cell viability, with values near 100% in all concentrations tested. CONCLUSION: RESULTS seem show that CS is a safe source of natural antioxidants with antifungal and antibacterial activity and no cytotoxicity, with potential usefulness for cosmetic applications.

In vivo skin irritation potential of a Castanea sativa (Chestnut) leaf extract, a putative natural antioxidant for topical application.

Topical application of natural antioxidants has proven to be effective in protecting the skin against ultraviolet-mediated oxidative damage and provides a straightforward way to strengthen the endogenous protection system. However, natural products can provoke skin adverse effects, such as allergic and irritant contact dermatitis. Skin irritation potential of Castanea sativa leaf ethanol:water (7:3) extract was investigated by performing an in vivo patch test in 20 volunteers. Before performing the irritation test, the selection of the solvent and extraction method was guided by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging test and polyphenols extraction (measured by the Folin Ciocalteu assay). Iron-chelating activity and the phenolic composition (high performance liquid chromatography/diode array detection) were evaluated for the extract obtained under optimized conditions. The extraction method adopted consisted in 5 short extractions (10 min.) with ethanol:water (7:3), performed at 40 degrees. The IC(50) found for the iron chelation and DPPH scavenging assays were 132.94 +/- 9.72 and 12.58 +/- 0.54 microg/ml (mean +/- S.E.M.), respectively. The total phenolic content was found to be 283.8 +/- 8.74 mg GAE/g extract (mean +/- S.E.M.). Five phenolic compounds were identified in the extract, namely, chlorogenic acid, ellagic acid, rutin, isoquercitrin and hyperoside. The patch test carried out showed that, with respect to irritant effects, this extract can be regarded as safe for topical application.

Oak leaf extract as topical antioxidant: free radical scavenging and iron chelating activities and in vivo skin irritation potential.

The topical application of antioxidants may be beneficial for the protection of the skin against UV damage. An extract of Quercus robur leaves was prepared and evaluated considering its putative application as topical antioxidant. The solvent and extractive method selection was monitored by 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging activity and polyphenols extraction (measured by the Folin Ciocalteu assay). Iron chelating activity and the phenolic composition (HPLC/DAD) were assessed on the extract obtained under optimized conditions. Skin irritation potential was investigated by performing an in vivo patch test in 19 volunteers. The extraction solvent which resulted in the highest activity was ethanol:water (4:6) and thus it was selected for further preparation of this extract. The IC50s for the iron chelation and DPPH scavenging assays were 153.8 +/- 26.3 microg x mL-1 and 7.53 +/- 0.71 microg x mL-1 (mean +/- SD), respectively. The total phenolic content was found to be 346.3 +/- 6.7 mg gallic acid equivalents (GAE)/g extract (mean +/- SD). Three phenolic compounds were identified in the extract namely: ellagic acid, rutin and hyperoside. The major identified component was ellagic acid. The patch test carried out showed that the extract can be regarded as safe for topical application.