Antioxidant properties and phenolic acid content in the pulp of five pumpkin species were evaluated. The following species cultivated in Poland were included: Cucurbita maxima ‘Bambino’, Cucurbita pepo ‘Kamo Kamo’, Cucurbita moschata ‘Butternut’, Cucurbita ficifolia ‘Chilacayote Squash’, and Cucurbita argyrosperma ‘Chinese Alphabet’. The content of polyphenolic compounds was determined by ultra-high performance liquid chromatography coupled with HPLC, while the total content of phenols and flavonoids and antioxidant properties were determined by spectrophotometric methods. Ten phenolic compounds (protocatechuic acid, p-hydroxybenzoic acid, catechin, chlorogenic acid, caffeic acid, p-coumaric acid, syringic acid, ferulic acid, salicylic acid, kaempferol) were identified. Phenolic acids were the most abundant compounds; the amount of syringic acid was found to be the highest, ranging from 0.44 (C. ficifolia) to 6.61 mg∙100 g⁻¹ FW (C. moschata). Moreover, two flavonoids were detected: catechin and kaempferol. They were found at their highest level of content in C. moschata pulp (catechins: 0.31 mg∙100 g⁻¹ FW; kaempferol: 0.06 mg∙100 g⁻¹ FW), with the lowest amount detected in C. ficifolia (catechins: 0.15 mg∙100 g⁻¹ FW; kaempferol below the limit of detection). Analysis of antioxidant potential showed significant differences depending on the species and the test used. The DPPH radical scavenging activity of C. maxima was 1.03 times higher than C. ficiofilia pulp and 11.60 times higher than C. pepo. In the case of the FRAP assay, the multiplicity of FRAP radical activity in C. maxima pulp was 4.65 times higher than C. Pepo pulp and only 1.08 times higher compared to C. ficifolia pulp. The study findings show the high health-promoting value of pumpkin pulp; however, the content of phenolic acids and antioxidant properties are species dependent.

The aim of the paper was to evaluate the phenolic acid content and antioxidant properties in potato cultivars with coloured flesh and bright flesh. The study material included eight cultivars of edible potato grown in a temperate climate in Poland. Five cultivars were potato tubers with coloured flesh: “Rote Emma”, “Blue Salad”, “Vitelotte”, “Red Emmalie”, and “Blue Congo”; and three were potato tubers with bright flesh: “Bella Rosa”, “Lord”, and “Tajfun”. In all potato samples under study, four phenolic acids were identified: chlorogenic acid, gallic acid, p-coumaric acid, and caffeic acid. The predominant acid was chlorogenic acid, the levels of which ranged from 62.95 mg·100 g⁻¹ FM to 126.77 mg·100 g⁻¹ FM. The total concentration of the identified phenolic acids was diverse and depended on the genotype of the cultivar and the tuber flesh colour, with coloured-fleshed potatoes having higher phenolic acid contents in comparison to bright-fleshed potato cultivars. The average concentration of phenolic acids in the samples was 89.19 mg∙100 g⁻¹ FM, and the average concentrations of the individual phenolic acids identified were as follows: chlorogenic acid (86.19 mg∙100 g⁻¹ FM), gallic acid (1.18 mg∙100 g⁻¹ FM), p-coumaric acid (0.64 mg∙100 g⁻¹ FM), and caffeic acid (1.18 mg∙100 g⁻¹ FM). In addition, three groups of anthocyanins were identified: pelargonidin-3,5-di-O-glucoside, peonidin-3,5-di-O-glucoside, and petunidin-3,5-di-O-glucoside. Anthocyanins were not found in the “Lord” or “Tajfun” varieties characterised by white tuber flesh. The predominant pigment was petunidin-3,5-di-O-glucoside, with an average content of 23.15 mg∙100 g⁻¹ FM, and the highest value was observed in the “Vitelotte” variety (51.27 mg∙100 g⁻¹ FM). The antioxidant activity of the flesh of the potatoes under study was diverse depending on flesh colour. The FRAP (Ferric Reducing Antioxidant Power) assay indicated higher antioxidant activity of coloured-fleshed potato cultivars. The highest concentration was identified in the “Vitelotte” cultivar flesh and was 114% higher than in the “Lord” cultivar. Similar dependencies were found in the case of the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay; however, in this case, the “Vitelotte” cultivar flesh demonstrated nearly 6.4 times higher antioxidant activity than the “Lord” cultivar. Summarizing our own research, we can conclude that potato varieties with coloured flesh are characterised by a higher content of biologically active substances, including phenolic acids, and antioxidant properties compared to potato tubers with bright flesh.

New plant oils as a potential natural source of nutraceutical compounds are still being sought. The main components of eight cultivars (‘Koral’, ‘Lucyna’, ‘Montmorency’, ‘Naumburger’, ‘Wanda’, ‘Wigor’, ‘Wołyńska’, and ‘Wróble’) of sour cherry (Prunus cerasus L.) grown in Poland, including crude fat, protein, and oil content, were evaluated. The extracted oils were analysed for chemical and biological activity. The oils had an average peroxide value of 1.49 mEq O₂/kg, acid value of 1.20 mg KOH/g, a saponification value of 184 mg of KOH/g, and iodine value of 120 g I₂/100 g of oil. The sour cherry oil contained linoleic (39.1–46.2%) and oleic (25.4–41.0%) acids as the major components with smaller concentrations of α-eleostearic acid (8.00–15.62%), palmitic acid (5.45–7.41%), and stearic acid (2.49–3.17%). The content of sterols and squalene varied significantly in all the studied cultivars and ranged between 336–973 mg/100 g and 66–102 mg/100 g of oil. The contents of total tocochromanols, polyphenols, and carotenoids were 119–164, 19.6–29.5, and 0.56–1.61 mg/100 g oil, respectively. The cultivar providing the highest amounts of oil and characterised by the highest content of PUFA (including linoleic acid), plant sterols, α-and β-tocopherol, as well as the highest total polyphenol and total carotenoids content was been found to be ‘Naumburger’. The antioxidant capacity of sour cherry kernel oils, measured using the DPPH^• and ABTS^•+ methods, ranged from 57.7 to 63.5 and from 38.2 to 43.2 mg trolox/100 g oil, respectively. The results of the present study provide important information about potential possibilities of application of Prunus cerasus kernel oils in cosmetic products and pharmaceuticals offering health benefits.

Rosa canina is well-known plant, and its fruits have been used for centuries. The seeds have been less utilized and remain untested. The objective of this study was to examine the physico-chemical properties of rosehip seeds and to identify potential applications based on their properties. The physico-chemical properties of the seeds were determined, including swelling index (2.51), color in the CIE L * a * b * space (b * = 26.2), as well as carbohydrate (79.2 g/100 g), soluble dietary fiber (71.6 g/100 g), protein (7.67 g/100 g), fat (6.23 g/100 g), and ash (1.96 g/100 g) content. Among the amino acids, glutamic acid dominated (1.58 mg/100 g), while among the fatty acids, linoleic acid (53.19%), linolenic acid (20.24%), and oleic acid (17.63%) were the most dominant. In addition, rosehip seeds contained large amounts of calcium (3851 mg/kg), potassium (2732 mg/kg), and phosphorus (991 mg/kg), as well as vitamin C (1783 μg/g). It was found that the content of other valuable phytochemicals, such as phenolic compounds (2633 μg/g) and carotenoids (3.13 μg/g) influenced the antioxidant properties of the tested raw material. This activity examined by the ferric-reducing antioxidant power (FRAP) and DPPH radical scavenging activity methods was assessed at a level of 191 and 229 μmol TE/g, respectively. The results indicate the potential use of rosehip seed, a by-product of the food processing industry, as a new high-value ingredient for health products, such as nutraceuticals, pharmaceuticals, and cosmeceuticals.

The liver is a highly metabolically active organ, and one of the causes of its dysfunction is the damage caused by drugs and their metabolites as well as dietary supplements and herbal preparations. A common feature of such damage is drugs, which allows it to be defined as drug-induced liver injury (DILI). In this review, we analysed available research findings in the global literature regarding the effects of green tea and/or its phenolic compounds on liver function in the context of protective action during prolonged exposure to xenobiotics. We focused on the direct detoxifying action of epigallocatechin gallate (EGCG) in the liver, the impact of EGCG on gut microbiota, and the influence of microbiota on liver health. We used 127 scientific research publications published between 2014 and 2024. Improving the effectiveness of DILI detection is essential to enhance the safety of patients at risk of liver damage and to develop methods for assessing the potential hepatotoxicity of a drug during the research phase. Often, drugs cannot be eliminated, but appropriate nutrition can strengthen the body and liver, which may mitigate adverse changes resulting from DILI. Polyphenols are promising owing to their strong antioxidant and anti-inflammatory properties as well as their prebiotic effects. Notably, EGCG is found in green tea. The results of the studies presented by various authors are very promising, although not without uncertainties. Therefore, future research should focus on elucidating the therapeutic and preventive mechanisms of polyphenols in the context of liver health through the functioning of gut microbiota affecting overall health, with particular emphasis on epigenetic pathways.

Marrubium vulgare (Lamiaceae) is a plant which has long been known and used in traditional medicine for various purposes. However, few recent studies have documented its chemical composition and biological properties. The present study investigated the phytochemical composition of horehound, as well as its protective, antioxidant, and antimicrobial potential. GC-MS analysis revealed that the major components of horehound essential oil are E-caryophyllene (35.7%), germacrene D (25.2%), and bicyclogermacrene (10.6%). The biological activity of horehound hydroethanolic herb extract derives from multiple chemical compounds, including polyphenols (55.72 mg/mL), flavonoids (11.01 mg/mL), phenolic acids (4.33 mg/mL), and tannins (4.46 mg/mL). Chromatographic analyses of the extract identified 12 phenolic compounds, of which ferulic acid, catechin, quercetin, protocatechuic acid, rutin, and syringic acid (35.42, 24.69, 20.65, 18.70, 14.46, and 12.69 mg/mL, respectively) were the main constituents. Its DPPH radical scavenging ability was 68.29%, while its antioxidant properties, determined by the FRAP method, were at the level of 1.22 mmol/L. Moreover, M. vulgare extract decreased the level of intracellular reactive oxygen species in the fibroblasts and keratinocytes in vitro, achieving the strongest antioxidant effect at a concentration of 2.5% in the case of both types of skin cells. Extracts from the horehound herb showed significant antimicrobial and anti-biofilm activity, confirming the plant’s potential in therapeutic applications against various microbial pathogens (gram-positive and gram-negative bacteria and fungi). The research results demonstrate the protective effect of horehound extract on the viability of both fibroblasts and keratinocytes in vitro. To sum up, M. vulgare, as a valuable natural material with high preventive and therapeutic effectiveness, is a potential candidate for new applications in the pharmaceutical and cosmetics industries.