Comprehensive and critical view on the anti-inflammatory and immunomodulatory role of natural phenolic antioxidants.

The immune response encompasses innate and adaptive immunity, each with distinct and specific activities. The innate immune system is constituted by phagocytic cells, macrophages, monocytes and neutrophils, the cascade system, and different classes of receptors such as toll-like receptors that are exploited by the innate immune cells. The adaptive immune system is antigen-specific, encompassing memory lymphocytes and the corresponding specific receptors. Inflammation is understood as an activation of different signaling pathways such as toll-like receptors or nuclear factor kappa-light-chain-enhancer of activated B cells, with an increase in nitric oxide, inflammatory cytokines and chemokines. Increased oxidative stress has been identified as main source of chronic inflammation. Phenolic antioxidants modulate the activities of lymphocytes and macrophages by impacting cytokines and nitric oxide release, exerting anti-inflammatory effect. The nuclear-factor kappa-light-chain-enhancer of activated B cells signaling pathway and the mitogen-activated protein kinase pathway are targeted, alongside an increase in nuclear factor erythroid 2-related factor mediated antioxidant response, triggering the activity of antioxidant enzymes. The inhibitive potential on phospholipase A2, cyclooxygenase and lipoxygenase in the arachidonic acid pathway, and the subsequent reduction in prostaglandin and leukotriene generation, reveals the potential of phenolics as inflammation antagonists. The immunomodulative potential encompasses the capacity to interfere with proinflammatory cytokine synthesis and with the expression of the corresponding genes. A diet rich in antioxidants can result in prevention of inflammation-related pathologies. More investigations are necessary to establish the role of these antioxidants in therapy. The appropriate delivery system and the prooxidant effects exhibited at large doses, or in the presence of heavy metal cations should be regarded.

Fighting coronaviruses with natural polyphenols.

Few licensed drugs and vaccines are available concerning COVID-19, a disease caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2). Furthermore, numerous recent SARS-COV-2 variants of have arisen globally, demonstrating the need to develop broadly protective interventions for different coronavirus strains. Polyphenols are the largest class of natural bioactive compounds, categorized as flavonoids (catechins, quercetin and kaempferol) and non-flavonoids (gallic acid and resveratrol), and these compounds have been described as effective antiviral agents. This is because they can inhibit coronavirus enzymes, blocking replication and infection. The present short manuscript aimed to summarize and report the current evidence from well-known powerful flavonoid (catechin, quercetin, and kaempferol) and non-flavonoid (gallic acid and resveratrol) polyphenols obtained from plant extracts that inhibit coronavirus strains in in vitro models or by computer modeling. The knowledge of strategies beyond conventional treatments may be helpful in the development of new coronavirus drugs, treatments/medicines, or formulations.

Flavonoid and Non-Flavonoid Compounds of Autumn Royal and Egnatia Grape Skin Extracts Affect Membrane PUFA's Profile and Cell Morphology in Human Colon Cancer Cell Lines.

Grapes contain many flavonoid and non-flavonoid compounds with anticancer effects. In this work we fully characterized the polyphenolic profile of two grape skin extracts (GSEs), Autumn Royal and Egnatia, and assessed their effects on Polyunsaturated Fatty Acid (PUFA) membrane levels of Caco2 and SW480 human colon cancer cell lines. Gene expression of 15-lipoxygenase-1 (15-LOX-1), and peroxisome proliferator-activated receptor gamma (PPAR-γ), as well as cell morphology, were evaluated. The polyphenolic composition was analyzed by Ultra-High-Performance Liquid Chromatography/Quadrupole-Time of Flight mass spectrometry (UHPLC/QTOF) analysis. PUFA levels were evaluated by gas chromatography, and gene expression levels of 15-LOX-1 and PPAR-γ were analyzed by real-time Polymerase Chain Reaction (PCR). Morphological cell changes caused by GSEs were identified by field emission scanning electron microscope (FE-SEM) and photomicrograph examination. We detected a different profile of flavonoid and non-flavonoid compounds in Autumn Royal and Egnatia GSEs. Cultured cells showed an increase of total PUFA levels mainly after treatment with Autumn Royal grape, and were richer in flavonoids when compared with the Egnatia variety. Both GSEs were able to affect 15-LOX-1 and PPAR-γ gene expression and cell morphology. Our results highlighted a new antitumor mechanism of GSEs that involves membrane PUFAs and their downstream pathways.

[Study on non-flavonoids chemical constituents from Spatholobi Caulis].

To study the non-flavonoids chemical constituents in water extract of Spatholobi Caulis. Some purification and analysis techniques like silica gel, D101-macroporous adsorptive resins, and Sephadex LH-20 column chromatographies as well as reversed phase high-performance liquid chromatography were used to isolate and analyze the phenolic acid esters and other type compounds from Spatholobi Caulis integrally. The structures of these compounds were identified by spectroscopic techniques such as nuclear magnetic resonance and high resolution mass spectrometries. Twenty-seven compounds, including phenolic acid, coumarin, lignan, terpene, alkaloid, and steroid compounds, were isolated from ethyl acetate and n-butanol fractions in water extract of Spatholobi Caulis, and they were identified as ß-sitosterol(1), feruli acid methyl ester(2), syringaresinol(3),(+)-medioresinol(4),(+)-epipinoresinol(5), p-acetylphenol(6), bolusanthin Ⅳ(7), evofolin B(8), salicylic acid(9), trans-p-hydroxy-cinnamic acid(10), abscisic acid(11), m-hydroxyphenol(12), C-veratroylglycol(13), p-hydroquinone(14), 8,9-dihydroxymegastigma-4,6-dien-3-one(15), p-hydroxybenzoic acid(16), 6,9-dihydroxymegastigma-4,7-dien-3-one(17), protocatechuic acid(18), protocatechuic acid methyl ester(19), 5,7-dihydroxycoumarin(20), isolariciresinol(21), nicotinic acid(22), daucosterol(23),(+)-pinoresinol(24), stigmasterol(25), allantoin(26) and koaburaside(27), respectively. Furthermore, compounds 2-15, 19-22, 24 and 26 were isolated from genus Spatholobus for the first time.

Abelmoschi Corolla non-flavonoid components altered the pharmacokinetic profile of its flavonoids in rat.

AIM: Abelmoschi Corolla is a well-known herbal medicine used for the treatment of chronic renal disease. Flavonoids are the major bioactive ingredients of Abelmoschi Corolla, but some non-flavonoid components also exist in this herb. In order to clarify the influences of non-flavonoid components on the pharmacokinetics profile of the flavonoid fraction from Abelmoschi Corolla (FFA), an investigation was carried out to compare the pharmacokinetic parameters of seven flavonoid components after administration of FFA and after administration of FFA combined with different non-flavonoid fractions. MATERIALS AND METHODS: A selective and sensitive UPLC-MS/MS method was established to determine the plasma concentrations of the seven compounds. Sprague-Dawley rats were allocated to four groups which orally administered FFA, FFA combined with macromolecular fraction (FFA-MF), FFA combined with small molecule fraction (FFA-SF) and FFA combined with MF-SF (FFA-MF-SF) with approximately the same dose of FFA. At different time points, the concentration of rutin (1), hyperoside (2), isoquercitrin (3), hibifolin (4), myricetin (5), quercetin-3'-O-glucose (6), quercetin (7) in rat plasma were determined and main pharmacokinetic parameters including T(1/2), T(max), AUC and C(max) were calculated using the DAS 2.0 software package. The statistical analysis was performed using the Student's t-test with P<0.05 as the level of significance. RESULTS: Flavonoids almost had similar pharmacokinetics profile that were rapidly absorbed, reached the peak concentration at 30-60 min in group A, but the pharmacokinetic profiles and parameters of these flavonoids changed when co-administered with non-flavonoid components. It was found that AUC of five flavonoids but not hibifolin and quercetin in group FFA-SF and group FFA-MF-SF increased (P<0.05) in comparison with group FFA while the tendency was not observed in group FFA-MF. Moreover, seven flavonoids had varying degrees of differences in the pharmacokinetics parameters such as C(max), T(max) and T(1/2) (P<0.05) in group FFA-MF, FFA-SF and FFA-MF-SF by comparison with group FFA. CONCLUSION: These results indicate that non-flavonoid components could improve the bioavailability and delay the elimination of some flavonoids in rat.