The Chemical Variability, Nutraceutical Value, and Food-Industry and Cosmetic Applications of Citrus Plants: A Critical Review

Citrus fruits occupy an important position in the context of the fruit trade, considering that both fresh fruits and processed products are produced on a large scale. Citrus fruits are recognized as an essential component of the human diet, thanks to their high content of beneficial nutrients such as vitamins, minerals, terpenes, flavonoids, coumarins and dietary fibers. Among these, a wide range of positive biological activities are attributed to terpenes and flavonoids derivatives. In this review, a list of bibliographic reports (from 2015 onwards) on the phytochemical composition, beneficial effects and potential applications of citrus fruits and their by-products is systematically summarized. In detail, information regarding the nutraceutical and medicinal value closely linked to the presence of numerous bioactive metabolites and their growing use in the food industry and food packaging, also considering any technological strategies such as encapsulation to guarantee their stability over time, were evaluated. In addition, since citrus fruit, as well as its by-products, are interesting alternatives for the reformulation of natural cosmetic products, the sector of the cosmetic industry is also explored. More in-depth knowledge of the latest information in this field will contribute to future conscious use of citrus fruits

Influence of rosmarinic acid and Salvia officinalis extracts on melanogenesis of B16F10 cells

Melanin is a photoprotective skin pigment, and pathologies characterized by hypo or hyperpigmentation are common. New compounds that regulate melanogenesis are, therefore, opportune, and many natural products with this property, as polyphenols, have been described. Salvia officinalis L., Lamiaceae, is a widely used food spice that contains high amounts of phenol derivates, including rosmarinic acid. The aim of this work was to evaluate the contribution of rosmarinic acid in the melanogenic activity of sage extracts. Fluid and aqueous extracts of sage and purified rosmarinic acid were assayed for B16F10 cytotoxicity and, then, evaluated on melanin production and tyrosinase activity. While sage extracts showed a concentration-dependent ability to significantly increase melanin production without necessarily changing the enzymatic activity, rosmarinic acid showed a dual behavior on melanogenesis, increasing melanin biosynthesis and tyrosinase activity at low concentrations and decreasing it at higher levels. Rosmarinic acid may collaborate with sage extracts activity on melanogenesis, although other compounds may be involved. This is the first time that a dual action of rosmarinic acid on melanogenesis is reported, which may be useful in further studies for therapeutic formulations to treat skin pigmentation disorders