The aim of the presented study was to characterize the content and biological activity of extracts prepared from dried Stevia rebaudiana leaves with potential application in the food or cosmetic industry. Aqueous (A), ethanolic (E) and glycol-aqueous (GA) extracts were analyzed for the content of polyphenols and proteins, showing that the highest amount of phenols (15.50 mg/g) and flavonoids (3.85 mg/g) contained GA. All extracts contained significant amount of protein (69.40–374.67 mg/g). Between analyzed stevia extracts (HPLC) GA contained the highest amount of polyphenols, especially ferulic (5.50 mg/g) and rozmaric (4.95 mg/g) acids derivates. The highest antiradical activity against DPPH• and ABTS•+ was noted for GA and E (IC50 = 0.38 and 0.71 µg flavonoids/mL). The highest ability to chelate Fe2+ was observed for E (IC50 = 2.08 µg flavonoids/mL). Stevia extracts were also analyzed for their cytotoxicity and fibroblast irritation potential in vitro. E and GA were the most cytotoxic and irritating, probably due to the high content of biologically active phytochemicals. On the other hand, a extract was the most tolerable by the cells. To summarize, the presented study evaluated the potential application of A, E and GA stevia extracts as natural source of antioxidants in the food and cosmetic industry.

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Due to the constantly growing interest in ingredients of natural origin, this study attempts to evaluate the possibility of using extracts from three Ayurvedic plants in preparations for the care and treatment of skin diseases. Therefore, studies of antioxidant properties were carried out using DPPH and ABTS radicals, obtaining 76% and 88% of these radical scavenging, respectively. A significant decrease in the intracellular level of free radicals and an increase in the activity of the antioxidant enzyme-superoxide dismutase by almost 60% were also observed. In addition, the extracts were assessed for anti-inflammatory and anti-aging properties, obtaining over 70% inhibition of lipoxygenase activity and almost 40% of collagenase. Additionally, the cytoprotective properties of the obtained extracts on skin cells, keratinocytes and fibroblasts, were demonstrated. To assess the content of biologically active compounds, HPLC-electrospray ionization (ESI)-MS/MS multiple reaction monitoring (MRM) analyses were performed. The obtained results show that all three analyzed plants are a valuable source of biologically active substances with desired properties in the context of skin cell protection. Particularly noteworthy is the extract of Epilobium angustifolium L., for which the most promising results were obtained.

Plant materials play a very significant role as components of products being used both for medicinal and cosmetic purposes. Due to the high content of active substances, they can play an important role as extracts with antioxidant, regenerative, and antiaging properties. The skin aging process depends on various pathological and physiological processes, among which the degradation of extracellular matrix biomolecules such as collagen and elastin, which significantly affect the maintenance of good skin condition, is very important. The secondary metabolites and plant extracts may have collagenase and elastase inhibitory activity. This activity is mainly due to the high content of a wide range of various biologically active compounds, such as polyphenols, which include, among others, flavonoids, phenolic acids, tocopherols, and tannins. The work involved a comprehensive assessment of the plant from Apiaceae family such as Meum athamanticum L., Centella asiatica L., and Aegopodium podagraria L. extract as a multifunctional raw material. During study antioxidant properties, phenolic compounds and flavonoids content, effect on collagenase and elastase enzyme activity (antiaging effect), cytotoxic properties on skin cells (keratinocytes and fibroblasts), and cell migration capacity were analyzed. It has been shown that the highest antioxidant capacity can be observed for the extract of herb of Aegopodium podagraria L. When the concentration reached 5% all tested extracts had a positive effect on the cell proliferation of both keratinocytes and fibroblasts. It turned out that the most promising inhibitor of collagenase and elastase enzymes was the extract from Aegopodium podagraria, which inhibits the activity of both enzymes by over 70% in the concentration of 5% positively affecting the condition of skin cells.

The skin is an organ that is constantly exposed to many external factors that can affect its structure and function. Due to the presence of different cannabinoid receptors on many types of skin cells, cannabinoids can interact directly with them. Therefore, as part of this work, the impact of two types of Cannabis sativa L. herb extracts on keratinocytes and fibroblasts was assessed. The content of biologically active compounds such as phenols, flavonoids, chlorophylls and cannabinoids was evaluated. The antioxidant capacity of prepared extracts using the DPPH radical, H2DCFDA probe and measurement of superoxide dismutase activity was also assessed. The cytotoxicity of hemp extracts was determined using the Alamar Blue, Neutral Red and LDH assays. The ability of the extracts to inhibit the activity of matrix metalloproteinases, collagenase and elastase, was assessed. Preparations of model hydrogels were also prepared and their effect on transepidermal water loss and skin hydration was measured. The obtained results indicate that hemp extracts can be a valuable source of biologically active substances that reduce oxidative stress, inhibit skin aging processes and positively affect the viability of skin cells. The analysis also showed that hydrogels based on cannabis extracts have a positive effect on skin hydration.