Francisca Rodrigues

Castanea sativa by-products: a review on added value and sustainable application

Castanea sativa Mill. is a species of the family Fagaceae abundant in south Europe and Asia. The fruits (chestnut) are an added value resource in producing countries. Chestnut economic value is increasing not only for nutritional qualities but also for the beneficial health effects related with its consumption. During chestnut processing, a large amount of waste material is generated namely inner shell, outer shell and leaves. Studies on chestnut by-products revealed a good profile of bioactive compounds with antioxidant, anticarcinogenic and cardioprotective properties. These agro-industrial wastes, after valorisation, can be used by other industries, such as pharmaceutical, food or cosmetics, generating more profits, reducing pollution costs and improving social, economic and environmental sustainability. The purpose of this review is to provide knowledge about the type of chestnut by-products produced, the studies concerning its chemical composition and biological activity, and also to discuss other possible applications of these materials.

Cell-based in vitro models for predicting drug permeability

Introduction: In vitro cell models have been used to predict drug permeation in early stages of drug development, since they represent an easy and reproducible method, allowing the tracking of drug absorption rate and mechanism, with an advantageous cost–benefit ratio. Such cell-based models are mainly composed of immortalized cells with an intrinsic ability to grow in a monolayer when seeded in permeable supports, maintaining their physiologic characteristics regarding epithelium cell physiology and functionality. Areas covered: This review summarizes the most important intestinal, pulmonary, nasal, vaginal, rectal, ocular and skin cell-based in vitro models for predicting the permeability of drugs. Moreover, the similitude between in vitro cell models and in vivo conditions are discussed, providing evidence that each model may provisionally resemble different drug absorption route. Expert opinion: Despite the widespread use of in vitro cell models for drug permeability and absorption evaluation purposes, a detailed study on the properties of these models and their in vitro–in vivo correlation compared with human data are required to further use in order to consider a future drug discovery optimization and clinical development.

Nanomedicine in the development of anti-HIV microbicides.

Prevention plays an invaluable role in the fight against HIV/AIDS. The use of microbicides is considered an interesting potential approach for topical pre-exposure prophylaxis of HIV sexual transmission. The prospects of having an effective product available are expected to be fulfilled in the near future as driven by recent and forthcoming results of clinical trials. Different dosage forms and delivery strategies have been proposed and tested for multiple microbicide drug candidates presently at different stages of the development pipeline. One particularly interesting approach comprises the application of nanomedicine principles to the development of novel anti-HIV microbicides, but its implications to efficacy and safety are not yet fully understood. Nanotechnology-based systems, either presenting inherent anti-HIV activity or acting as drug nanocarriers, may significantly influence features such as drug solubility, stability of active payloads, drug release, interactions between active moieties and virus/cells, intracellular drug delivery, drug targeting, safety, antiviral activity, mucoadhesive behavior, drug distribution and tissue penetration, and pharmacokinetics. The present manuscript provides a comprehensive and holistic overview of these topics as relevant to the development of vaginal and rectal microbicides. In particular, recent advances pertaining inherently active microbicide nanosystems and microbicide drug nanocarriers are discussed.

Coffee silverskin: A possible valuable cosmetic ingredient

Abstract 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 Fe2+/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.

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.

Application of Coffee Silverskin in cosmetic formulations: physical/antioxidant stability studies and cytotoxicity effects.

Abstract Context: Currently, there is an increasing interest of cosmetic industry on natural extracts. The inclusion of antioxidants in topical formulations can contribute to minimize oxidative stress in the skin, which has been associated with aging. Also, questions of sustainability are leading to the study of new cosmetic ingredients obtained from food by-products. Coffee Silverskin (CS) is a food by-product with established antioxidant activity that has not yet been incorporated into a topical formulation. Objective: The aim of this study was to evaluate the physical and microbiological stabilities and antioxidant activity of a hand cream formulation containing 2.5% (w/w) of CS extract upon production and after 6 months of shelf-life and in vitro safety/cytotoxicity on skin cell lines after production. Materials and methods: The in vitro cytotoxicity was evaluated with MTS and LDH assays, at different concentrations, in HaCaT and HFF-1 cells. Formulations were stored at 25 °C/65% RH and 40 °C/75% RH. Physical, microbiological, and antioxidant stabilities were evaluated by centrifugation, viscosity, total colony count, DPPH and total phenolic content (TPC). Results: The hand cream containing 2.5% (w/w) of CS extract showed stable physical characteristics independently of the storage conditions. The DPPH activity and TPC of the CS formulation were significantly higher compared with those of the base formulation. However, during storage, the antioxidant activity decreases slightly. Microbiological quality was also confirmed. No cytotoxic effects were observed. Conclusion: It is possible to suggest that this formulation is stable under extreme conditions and safe for topical use.

In vitro and in vivo comparative study of cosmetic ingredients Coffee silverskin and hyaluronic acid

Keywords: anti-ageing efficacy; Coffee silverskin; cutometer; franz cells; skin biophysical techniques

Permeation of topically applied caffeine from a food by—product in cosmetic formulations: Is nanoscale in vitro approach an option?

The aim of the present work was to develop and evaluate the potential of nanostructured lipid carriers associated with caffeine extracted from Coffee Silverskin (NLC-CS), a food by-product, as a new possible topical therapy of cellulitis. Caffeine gain increasing research interest due to their cosmetic potential, particularly in gynoid lipodystrophy, commonly known as cellulite. NLC-CS were prepared via double emulsion technique using polysorbate 60 as surfactant and characterized for their morphology, particle size, zeta potential, association encapsulation and stability. The in vitro skin permeation studies were performed on Franz diffusion cells using pig skin ear as permeation membrane and the optimized formulation was compared with a hydroalcoholic solution of Coffee silverskin (CS) extract. NLC-CS were within the nanosized range (≈200nm), with a low polydispersity index (<0.25) and zeta potential values around -30Mv, presenting storage stability up to 180days at 25°C/65% relative humidity (RH) and 40°C/75% RH. The association efficiency (AE) of caffeine was about 30% at production time and after storage period. Cryo-SEM images confirmed the spherical shape of NLC-CS. The in vitro skin permeation study demonstrated that NLC-CS had a similar skin permeation profile when compared to caffeine in CS extract.

Evaluation of radical scavenging activity, intestinal cell viability and antifungal activity of Brazilian propolis by-product

Propolis is a natural adhesive resinous compound produced by honeybees to protect hives from bacteria and fungi, being extremely expensive for food industry. During propolis production, a resinous by-product is formed. This resinous waste is currently undervalued and underexploited. Accordingly, in this study the proximate physical and chemical quality, as well as the antioxidant activity, radical scavenging activity and cell viability of this by-product were evaluated and compared with propolis in order to boost new applications in food and pharmaceutical industries. The results revealed that the by-product meets the physical and chemical quality standards expected and showed that the propolis waste contains similar amounts of total phenolic content (TPC) and total flavonoid content (TFC) to propolis. Also, a good scavenging activity against reactive oxygen and nitrogen species (ROS and RNS, respectively) determined by the assays of superoxide anion radical (O2-), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), nitric oxide (NO) and peroxyl radical (ROO) were determined. Linear positive correlations were established between the TPC of both samples and the antioxidant activity evaluated by three different methods (DPPH, ABTS and FRAP assays). The extracts were also screened for cell viability assays in two different intestinal cell lines (HT29-MTX and Caco-2), showing a viability concentration-dependent. Similarly, the Artemia salina assay, used to assess toxicity, demonstrated the concentration influence on results. Finally, the antifungal activity against ATCC species of Candida was demonstrated. These results suggest that propolis by-product can be used as a new rich source of bioactive compounds for different areas, such as food or pharmaceutical.

State of the art in coffee processing by-products

Abstract This chapter describes the steps involved in coffee processing from the field to the cup and the respective generation of by-products along the chain. The chemical composition of coffee husks, pulp, immature, and defective beans, coffee silverskin, and spent coffee grounds is detailed and methods for the sustainable management of these by-products are addressed, as well as legislative frameworks and policy recommendations. Although coffee by-products have a high potential of application in different fields, more integrated strategies with the involvement of coffee producers, industries, academic institutions, governmental and nongovernmental organizations are still needed to convert coffee by-products into really profitable substrates.