Polyphenols and Maillard Reaction Products in Dried Prunus spinosa Fruits: Quality Aspects and Contribution to Anti-Inflammatory and Antioxidant Activity in Human Immune Cells Ex Vivo

• Published in: Molecules (Basel, Switzerland) Switzerland), 2022-05, Vol.27 (10), p.3302
• Main Authors: Magiera, Anna, Czerwińska, Monika Ewa, Owczarek, Aleksandra, Marchelak, Anna, Granica, Sebastian, Olszewska, Monika Anna
• Format: Article
• Language: English
• Subjects: 5-hydroxymethylfurfural; Anti-Inflammatory Agents - chemistry; Antioxidants; Antioxidants - chemistry; Biological activity; Chlorogenic acid; Chromatography, Liquid; Drying; Elastase; Flavonoids; Food preservation; Fruit - chemistry; Fruits; Glycation End Products, Advanced - analysis; High-performance liquid chromatography; Humans; Hydroxymethylfurfural; Immune system; Inflammatory diseases; Interleukin 10; Interleukin 6; Interleukin 8; LC–MS; Leukocytes (neutrophilic); Leukocytes, Mononuclear; Liquid chromatography; Maillard reaction; Maillard reaction products; Neutrophils; NMR; Nuclear magnetic resonance; Oxidants; Oxidizing agents; Peripheral blood mononuclear cells; Phenolic acids; phenolics; Phenols; Phytochemicals; Plant Extracts - chemistry; Polyphenols; Polyphenols - chemistry; Prunus - chemistry; Prunus spinosa; Prunus spinosa fruits; Quality control; Quercetin; Statistical correlation; Tandem Mass Spectrometry; Tumor necrosis factor-TNF; Tumor necrosis factor-α
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27103302

Dried fruits (sloes) are folk phytotherapeutics applied to treat chronic inflammatory disorders. However, their pharmacological potential, activity vectors, and drying-related changes in bioactive components remain unexplored. Therefore, the present research aimed to evaluate the anti-inflammatory and antioxidant effects of dried sloes in ex vivo models of human neutrophils and peripheral blood mononuclear cells (PMBCs) and establish their main active components. It was revealed that the fruit extracts significantly and dose-dependently inhibited the respiratory burst, downregulated the production of elastase (ELA-2) and TNF-α, and upregulated the IL-10 secretion by immune cells under pro-inflammatory and pro-oxidant stimulation. The slightly reduced IL-6 and IL-8 secretion was also observed. The structural identification of active compounds, including 45 phenolics and three Maillard reaction products (MRPs) which were formed during drying, was performed by an integrated approach combining LC-MS/MS, preparative HPLC isolation, and NMR studies. The cellular tests of four isolated model compounds (chlorogenic acid, quercetin, procyanidin B2, and 5-hydroxymethylfurfural), supported by statistical correlation studies, revealed a significant polyphenolic contribution and a slight impact of MRPs on the extracts' effects. Moreover, a substantial synergy was observed for phenolic acids, flavonoids, condensed proanthocyanidins, and MPRs. These results might support the phytotherapeutic use of dried fruits to relieve inflammation and establish the quality control procedure for the extracts prepared thereof.