Assessment of Cucurbita spp. Peel Extracts as Potential Sources of Active Substances for Skin Care and Dermatology

Abstract

By-products of cultivated plants are one of the major environmental concerns worldwide. Due to the high concentration of bioactive chemicals, such waste may be considered hazardous due to the interference with the plant growth, deterioration of the drinking water quality or toxic effects on sensitive marine organisms. Moreover, plant-derived by-products, with proper handling, may represent a low-cost source of bioactive compounds potentially important for pharmaceutical and cosmetics industries. The aim of the study was to evaluate the phytochemical composition, antioxidant activity, the influence of tyrosinase activity, in vitro sun protecting factor and cytotoxicity of 15 extracts from peels of five cultivars of Cucurbita maxima and C. moschata. The extracts were prepared using “green solvents” (water, 50% propylene glycol, and 20% ethanol) and ultrasound-assisted extraction. The performed analysis showed that the peel extracts from various cultivars differ significantly in respect to the phytochemical content and activity. The type of solvent also had a significant impact on the extract’s composition and bioactivity. Aqueous peel extracts contained the highest amounts of flavonoids, showed the greatest antioxidant potential and the most significant in vitro SPF values. In vitro studies showed that the analyzed peel extracts are not cytotoxic for human keratinocytes up to the concentration of 1000 µg/mL and thus might be considered as non-irritant for the skin. The study confirms the potential application of peel extracts from Cucurbita spp. cultivars in cosmetic products.

Essential oil from Citrus depressa peel exhibits antimicrobial, antioxidant and cancer chemopreventive effects

“…3 Furthermore, the integration of phytochemicals with antibacterial properties in care products can extend their useful life at the same time as serving as natural preservatives. 4 National health standards require that skincare and beauty products be free from specific pathogenic microorganisms, such as Candida albicans, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. 5 Staphylococcus aureus is commonly found on the skin, hair, nasal cavities, throat, mucous membranes and feces, particularly in cases of suppurative wounds.…”

“…Modern consumers prefer products formulated with natural ingredients to avoid skin irritation and chemical damage, at the same time as minimizing environmental impact 3 . Furthermore, the integration of phytochemicals with antibacterial properties in care products can extend their useful life at the same time as serving as natural preservatives 4 . National health standards require that skincare and beauty products be free from specific pathogenic microorganisms, such as Candida albicans , Escherichia coli , Pseudomonas aeruginosa and Staphylococcus aureus 5 .…”

Pulp or Peel? Comparative Analysis of the Phytochemical Content and Selected Cosmetic-Related Properties of Annona cherimola L., Diospyros kaki Thumb., Cydonia oblonga Mill. and Fortunella margarita Swingle Pulp and Peel Extracts

“…The antioxidant capacity of flesh and peel extracts was compared using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), scavenging assays, according to the protocols described by Matejić et al [ 85 ], with further modifications [ 87 ]. The extracts were analyzed in a concentration range of 0–50% ( v/v ), and the percentage of radical scavenging for each concentration was calculated from the formula below: % of ABTS/DPPH scavenging = [1 − (Abs(S)/Abs(C))] × 100 where Abs(S)—the corrected absorbance of the extract, Abs(C)—the corrected absorbance of the control sample.…”

Valorization of Pumpkin Byproducts: Antioxidant Activity and Carotenoid Characterization of Extracts from Peel and Filaments

“…The literature around spectrophotometric and chromatographic data of carotenoids from pumpkin waste is very lacking, especially when it concerns filaments, and generally focuses on the phenol fraction or other bioactive compounds [5,21,22]. In addition, it must be highlighted that the composition of pumpkin waste can change based on pumpkin variety, harvesting time, conditions, and methods of extraction [23][24][25].…”