Chickpeas are rich sources of bioactive compounds such as phenolic acids, flavonoids, and isoflavonoids. However, the contribution of insoluble-bound phenolics to their antioxidant properties remains unclear. Four varieties of chickpeas were evaluated for the presence of soluble (free and esterified) and insoluble-bound phenolics as well as their antiradical activity, reducing power and inhibition of peroxyl-induced cytotoxicity in human HuH-7 cells. In general, the insoluble-bound fraction showed a higher total phenolic content. Phenolic acids, flavonoids, and isoflavonoids were identified and quantified by UPLC-MS/MS. Taxifolin was identified for the first time in chickpeas. However, m-hydroxybenzoic acid, taxifolin, and biochanin A were the main phenolics found. Biochanin A was mostly found in the free fraction, while m-hydroxybenzoic acid was present mainly in the insoluble-bound form. The insoluble-bound fraction made a significant contribution to the reducing power and antiradical activity towards peroxyl radical. Furthermore, all extracts decreased the oxidative damage of human HuH-7 cells induced by peroxyl radicals, thus indicating their hepatoprotective potential. This study demonstrates that the antioxidant properties and bioactive potential of insoluble-bound phenolics of chickpeas should not be neglected.
Grape pomace is a major by-product of winemaking and a rich source of phenolic compounds with antioxidant potential. The Carménère variety, emblematic of Chilean viticulture, remains underutilized despite its high anthocyanin and flavanol content. This study aimed to develop a cost-effective method to recover and stabilize bioactive compounds from Carménère grape pomace. Five extracts were obtained using ethanol–water mixtures (0–100%) and characterized by HPLC-DAD and antioxidant assays (DPPH, FRAP, ORAC-FL). The 80% ethanol extract (EET-80) showed the highest antioxidant capacity (FRAP: 2909.3 ± 37.6; ORAC-FL: 1864.3 ± 157.8 µmol TE/g dw) and was selected for microencapsulation via spray drying using maltodextrin. This scalable technique protects thermosensitive compounds and enhances their applicability. The optimized 1:50 extract-to-carrier ratio achieved high encapsulation efficiency (85.7 ± 0.7%). In Caco-2 cells, the microencapsulated extract (5–250 µg/mL) showed no alteration in metabolic activity and significantly reduced intracellular ROS levels (65% inhibition at 250 µg/mL). Solvent polarity selectively influenced polyphenol recovery—50% ethanol favored catechin (581.1 µg/g) and epicatechin (1788.3 µg/g), while 80% ethanol enhanced malvidin-3-O-glucoside (118.0 µg/g). These findings support the valorization of Carménère grape pomace as a sustainable source of antioxidants and highlight the role of microencapsulation in improving extract stability and functionality.
The association between dietary fiber and phenolic compounds allows the latter to reach the colon, where most polysaccharides undergo fermentation. This bioprocessing weakens the matrix and promotes the release of the phenolic compounds, which then exert beneficial effects on intestinal function. Although this notion is widely accepted, supporting evidence remains scarce. In this study, we subjected grape pomace skin to in vitro digestion to obtain an indigestible fraction suitable for SHIME bioreactors. Throughout these stages, we observed a sequential increase in the release of phenolic compounds, with colonic fermentation playing an important role. Although we did not observe an increase in short-chain fatty acid (SCFA) production by the gut microbiota, we performed a repeated-challenge design on differentiated Caco-2 monolayers. With this approach, we found that the phenolic-rich ferment prevented the transepithelial electrical resistance (TEER) drop on the second challenge and modulated the transcriptomic profile assessed by RNA-seq. Our findings indicate that the Caco-2 cellular responses mentioned above were SCFA-independent and likely due to the differential impact of phenolic compound load after colonic fermentation of grape pomace skin.
Red wine grape pomace (RWGP), a winemaking by-product rich in phenolics, flavonoids, and dietary fiber, has shown promise in mitigating cardiovascular disease (CVD), however, its mechanisms of action remain incompletely understood. This study comprehensively profiled the phenolic composition of RWGP—including free, esterified, etherified, and insoluble-bound fractions—and evaluated the effects of RWGP dietary supplementation on gut barrier integrity, inflammation, oxidative stress, and survival in SR-B1−/−ApoE-R61h/h mice, a model of diet-induced lethal ischemic heart disease. RWGP supplementation significantly improved survival rates and restored gut barrier function, as evidenced by lower plasma FITC-dextran and LPS levels, increased circulating ZO-1 levels, and reduced histopathological colon damage. In addition, RWGP reduced pro-inflammatory cytokines (IL-1) and showed a trend toward attenuating systemic oxidative stress (TBARS). Analysis of phenolic compounds indicated a significant presence of insoluble-bound phenolics. Nevertheless, the beneficial effects observed are likely attributable to the synergistic actions of RWGP’s complex phytochemical and fiber composition. These results highlight RWGP’s potential as a sustainable, gut-targeted functional food ingredient for CVD prevention and management.
Background/Objectives: Cellular senescence and oxidative stress contribute to macrophage dysfunction and chronic inflammation during aging. Buddleja globosa (matico) is traditionally consumed as an infusion and has reported antioxidant and anti-inflammatory properties. This study evaluated whether an aqueous extract of B. globosa (BgAE) modulates senescence-associated responses in THP-1-derived macrophages exposed to hydrogen peroxide. Methods: The phenolic profile of BgAE was analyzed by HPLC-DAD and its antioxidant capacity by the oxygen radical absorbance capacity assay. Cell viability was assessed after exposure to 0.01–50 µg/mL BgAE. THP-1-derived macrophages were pretreated with BgAE for 48 h, exposed to 50 µM H2O2 for 1 h, and allowed to recover for 5 days. Senescence-associated β-galactosidase, inflammatory gene expression, and p16, p21, phosphorylated NF-κB, and total NF-κB protein levels were evaluated. Results: BgAE showed antioxidant capacity and did not significantly reduce cell viability under the conditions tested. H2O2 increased senescence-associated β-galactosidase positivity, TNFA expression, p16 and p21 abundance, and NF-κB phosphorylation. BgAE reduced H2O2-induced β-galactosidase positivity at 1 and 50 µg/mL and modulated TNFA, p16, p21, and NF-κB responses, with effects varying across the concentrations evaluated. The 0.01 and 1 µg/mL conditions generally showed greater attenuation of H2O2-induced changes, whereas 50 µg/mL BgAE alone increased senescence-associated signaling. Conclusions: BgAE modulates selected senescence-associated and inflammatory responses in oxidatively stressed THP-1-derived macrophages. These findings provide initial in vitro evidence supporting further investigation and improved standardization of B. globosa aqueous preparations as modulators of oxidative stress-associated cellular responses.