Fruit peels might be a valuable source of active ingredients for cosmetics, leading to more sustainable usage of plant by-products. The aim of the study was to evaluate the phytochemical content and selected biological properties of hydroglycolic extracts from peels and pulps of Annona cherimola, Diospyros kaki, Cydonia oblonga, and Fortunella margarita as potential cosmetic ingredients. Peel and pulp extracts were compared for their antiradical activity (using DPPH and ABTS radical scavenging assays), skin-lightening potential (tyrosinase inhibitory assay), sun protection factor (SPF), and cytotoxicity toward human fibroblast, keratinocyte, and melanoma cell lines. The total content of polyphenols and/or flavonoids was significantly higher in peel than in pulp extracts, and the composition of particular active compounds was also markedly different. The HPLC-MS fingerprinting revealed the presence of catechin, epicatechin and rutoside in the peel of D. kaki, whereas kaempferol glucoside and procyanidin A were present only in the pulp. In A. cherimola, catechin, epicatechin and rutoside were identified only in the peel of the fruit, whereas procyanidins were traced only in the pulp extracts. Quercetin and luteolinidin were found to be characteristic compounds of F. margarita peel extract. Naringenin and hesperidin were found only in the pulp of F. margarita. The most significant compositional variety between the peel and pulp extracts was observed for C. oblonga: Peel extracts contained a higher number of active components (e.g., vicenin-2, kaempferol rutinoside, or kaempferol galactoside) than pulp extract. The radical scavenging potential of peel extracts was higher than of the pulp extracts. D. kaki and F. margarita peel and pulp extracts inhibited mushroom and murine tyrosinases at comparable levels. The C. oblonga pulp extract was a more potent mushroom tyrosinase inhibitor than the peel extract. Peel extract of A. cherimola inhibited mushroom tyrosinase but activated the murine enzyme. F. margarita pulp and peel extracts showed the highest in vitro SPF. A. cherimola, D. kaki, and F. margarita extracts were not cytotoxic for fibroblasts and keratinocytes up to a concentration of 2% (v/v) and the peel extracts were cytotoxic for A375 melanoma cells. To summarize, peel extracts from all analyzed fruit showed comparable or better cosmetic-related properties than pulp extracts and might be considered multifunctional active ingredients of skin lightening, anti-aging, and protective cosmetics.

The genus Vaccinium is represented by shrubs growing in a temperate climate that have been used for ages as traditional remedies in the treatment of digestive problems, in diabetes, renal stones or as antiseptics due to the presence of polyphenols (anthocyanins, flavonoids and tannins) in their fruits and leaves. Recent studies confirm their marked potential in the treatment of skin disorders and as skin care cosmetics. The aim of this review is to present the role of Vaccinium spp. as cosmetic products, highlight their potential and prove the biological properties exerted by the extracts from different species that can be useful for the preparation of innovative cosmetics. In the manuscript both skin care and therapeutic applications of the representatives of this gender will be discussed that include the antioxidant, skin lightening, UV-protective, antimicrobial, anti-inflammatory, and chemopreventive properties to shed new light on these underestimated plants.

Papaver nudicaule L. is a medicinal plant traditionally used in Asian ethnomedicine, yet its phytochemical composition and biological activity remain insufficiently explored. This study bridges phytochemistry and neuroactive potential. It includes metabolite profiling with bioactivity-guided fractionation, performed to evaluate its potential as a source of acetylcholinesterase (AChE) inhibitors. The methanolic extract of the aerial parts was analysed using HPLC–ESI–QTOF-MS/MS, which enabled the tentative identification of 34 compounds, predominantly isoquinoline alkaloids and flavonoid derivatives. The extract was subsequently fractionated by centrifugal partition chromatography (CPC) using an optimised biphasic solvent system, yielding fractions enriched in alkaloid constituents. The obtained fractions were evaluated for AChE inhibitory activity, revealing significantly higher activity than that of the crude extract. The most active fractions exhibited marked inhibition based on the comparison with the reference compound berberine, indicating effective enrichment of bioactive metabolites. Further analysis demonstrated that the activity of the most potent fraction was associated with the presence of amurensinine, which was purified by preparative HPLC and subsequently identified by NMR and LC-MS. The Papaver nudicaule extract showed no significant cytotoxicity toward SH-SY5Y neuronal cells up to 200 µg/mL, whereas the amurensinine-containing fraction reduced cell viability only at higher concentrations (≥100 µg/mL). Notably, when expressed in the micromolar range, this effect corresponds to relatively weak cytotoxicity, suggesting a potential safety margin at lower, biologically relevant concentrations. These findings demonstrate that P. nudicaule possesses a highly diverse alkaloid profile and represents a promising natural source of compounds with potential relevance for the development of agents targeting neurodegenerative disorders.

Background/Objectives: The identification of acetylcholinesterase (AChE) inhibitors from complex natural matrices remains challenging due to the limitations of conventional colorimetric assays. This study aimed to develop a fluorescence-based AChE inhibition assay (FAIA) suitable for screening plant extracts, while simultaneously characterizing the metabolite profile of Berberis julianae fruits, identifying bioactive alkaloid-enriched fractions, and evaluating their cytotoxicity in neuronal cell models. Methods: Methanolic extracts of B. julianae fruits were profiled by HPLC-ESI-QTOF-MS/MS and fractionated using centrifugal partition chromatography (CPC). The developed FAIA, based on 4-methylumbelliferyl acetate as a fluorogenic substrate, was optimized and validated using berberine as a reference inhibitor. CPC fractions and selected protoberberine alkaloids were screened for AChE-inhibitory activity, while cytotoxicity was assessed in differentiated and undifferentiated SH-SY5Y cells using the resazurin assay. Results: Twenty-five metabolites, including eight isoquinoline alkaloids, were tentatively identified in the fruit extract. The optimized FAIA enabled reliable evaluation of AChE inhibition without the limitations associated with chromogenic assays. Among the CPC fractions, fraction 7 exhibited the strongest inhibitory activity. LC-MS analysis revealed that this fraction was enriched in protoberberine alkaloids, including berberine, palmatine, jatrorrhizine, magnocurarine, and demethyleneberberine. Cytotoxicity studies demonstrated concentration-dependent effects of both the isolated fractions and the individual alkaloids, with differentiated and undifferentiated SH-SY5Y cells exhibiting distinct sensitivity profiles. At 200 µg/mL, cell viability ranged from approximately 20–40% in undifferentiated SH-SY5Y cells and from approximately 25–45% in differentiated SH-SY5Y cells, depending on the CPC fraction. Among the tested protoberberine alkaloids, demethyleneberberine exhibited the lowest cytotoxic effect, maintaining the highest viability of differentiated SH-SY5Y cells, followed by jatrorrhizine and berberine. Conclusions: The proposed FAIA represents a sensitive and practical approach for screening AChE inhibitors in complex plant matrices. Combined with metabolomic profiling and CPC-based bioassay-guided fractionation, it enabled the identification of alkaloid-rich fractions of B. julianae with pronounced anti-AChE activity. These findings support the applicability of the developed workflow for natural-product-based drug discovery targeting neurodegenerative disorders.