Hyperhomocysteinemia (HHcy), a risk factor for cardiovascular, neurodegenerative, and metabolic dysfunctions in humans, has been recapitulated in murine models by genetic and dietary modifications. The relevance of HHcy in clinical and experimental settings has led to the development of various analytical techniques with varying sensitivity and sample volume requirements. This study uses a fit-for-purpose, small-volume LC-MS/MS workflow to quantify plasma homocysteine (Hcy), methionine (Met), and cysteine (Cys) in a diet-induced HHcy mouse model. Using these assays that overcome limitations imposed by sample availability in small animals, our study evaluated circulating levels of these amino acids in C57BL/6 mice fed a HHcy-inducing diet rich in Met and lacking vitamins B6, B9, and B12. The increased Hcy and decreased Cys plasma concentrations observed in these mice correlated with decreased glutathione concentrations in brain homogenates and concomitant increase in the activity of the antioxidant enzyme Glutathione-S-Transferase and in the levels of the lipid peroxidation marker malondialdehyde. Overall, our work links plasma HHcy to the induction of brain oxidative stress, supporting the role of dietary modifications as complementary therapeutic strategies for neurodegenerative conditions.
Citrus processing by-products represent a sustainable source of bioactive plant complexes with potential applications in intestinal health. This study investigated the effects of standardized food-grade orange (OE) and lemon (LE) pomace extracts and their simulated gastrointestinal digestates (DIGs) on intestinal epithelial responses and selected probiotic strains. Caco-2 cells were used to assess cytotoxicity, epithelial wound closure, and, in differentiated monolayers challenged with lipopolysaccharide (LPS), extracellular levels of SOD2, catalase, Nrf2, IL-6, IL-8, TNF-α, and IL-1β. In parallel, the effects of OE, LE, and their corresponding DIGs on the growth and cell-surface hydrophobicity of four probiotic lactic acid bacteria were evaluated. OE and LE DIGs were non-cytotoxic and promoted epithelial wound closure in a concentration- and time-dependent manner. In LPS-challenged monolayers, both DIGs counteracted alterations in extracellular oxidative stress-related proteins and reduced pro-inflammatory cytokine levels without affecting cell viability. OE and LE also produced strain-dependent effects on probiotic growth and cell-surface hydrophobicity, which were modified by gastrointestinal digestion. Overall, these findings extend previous evidence on the intestinal bioactivity of Citrus pomace-derived plant complexes and support their further investigation as sustainable food-grade ingredients for gut health applications.
Macrophage activation depends on the balance between pro-inflammatory signaling and cytoprotective antioxidant responses. Persistent nuclear factor kappa B (NF-κB) and inducible nitric oxide synthase (iNOS) activity, together with insufficient nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, promotes oxidative and nitrosative stress and contributes to chronic inflammation. Phenylethanoid- and flavonoid-rich botanical extracts may modulate this immune-redox network, but the available evidence is dispersed across plant species, extraction procedures, isolated compounds, and experimental models. This review examines the phytochemical composition and biological effects of these preparations, with particular emphasis on Buddleja globosa Hope. Evidence concerning verbascoside, luteolin, apigenin, quercetin derivatives, and other constituents is integrated with findings related to toll-like receptor 4/NF-κB signaling, iNOS-derived nitric oxide, inflammatory cytokines, reactive oxygen species, and Keap1–Nrf2-dependent cytoprotective responses. Direct evidence obtained with B. globosa extracts is distinguished from mechanistic findings generated using isolated constituents or related botanical preparations. Current studies support antioxidant and inflammation-modulating activities, but interpretation is limited by phytochemical variability, inconsistent dosing, incomplete cytotoxicity assessment, and limited use of macrophage-specific models. Future work should prioritize chemically standardized extracts, direct extract–constituent comparisons, pathway-specific validation, and formulation strategies that improve stability, reproducibility, and biological performance.
Oxidative stress and chronic inflammation are major contributors to skin photoaging, highlighting the need for natural antioxidants with multifunctional bioactivities. This study developed an ultrasound-assisted extraction (UAE) strategy to recover an astaxanthin-rich extract from the underutilized freshwater macroalga Chara corallina and evaluated its antioxidant, anti-inflammatory, and anti-photoaging properties. Different solvent systems were evaluated for extraction efficiency, and astaxanthin-equivalent recovery was quantified by high-performance liquid chromatography with photodiode array detection (HPLC–PDA). Antioxidant activity was evaluated using the DPPH radical scavenging assay, whereas biological activities were assessed in human dermal fibroblasts and RAW264.7 macrophages using cell viability assays, quantitative real-time PCR, and extracellular matrix-related enzyme inhibition assays. The selected solvent system (48% ethanol in ethyl acetate) provided the highest astaxanthin-equivalent recovery (0.2598 ± 0.0086% w/w). The selected CCE exhibited DPPH radical-scavenging activity, modulated antioxidant- and inflammation-associated gene expression, increased COL1A2 mRNA expression, and inhibited collagenase, elastase, and hyaluronidase within the evaluated concentration range. HPLC–PDA analysis revealed a chromatographic component with retention-time and UV–visible spectral characteristics corresponding to those of an authentic astaxanthin reference standard; however, comprehensive structural and phytochemical characterization was not performed. Because CCE is a chemically complex extract, the observed biological responses cannot be attributed exclusively to astaxanthin. Overall, these findings provide an initial basis for further investigation of C. corallina as an underexplored freshwater source of carotenoid-containing bioactive extracts rather than establishing it as a commercially competitive source of natural astaxanthin.
Background: Endotoxemia and oxidative stress may contribute to adverse body-composition changes in patients receiving maintenance hemodialysis, but their relationships with adiposity and muscularity remain incompletely defined. We investigated whether the concentrations of circulating lipopolysaccharide (LPS), soluble NOX2-derived peptide (sNox2-dp), and hydrogen peroxide (H2O2) showed differential associations with bioimpedance-derived body-composition compartments and explored their relationships with normalized protein catabolic rate (nPCR), a surrogate of protein intake. Methods: In this observational, cross-sectional study, adult patients receiving maintenance hemodialysis were enrolled at a single center. Serum LPS and sNox2-dp and H2O2 concentrations were measured before dialysis. Body composition was assessed by bioimpedance analysis; fat mass (FM) was used as an index of adiposity, whereas intracellular water indexed to height squared (ICW/h2) was used as a proxy of muscularity. Associations were examined using Spearman correlation and multivariable linear regression adjusted for age, sex, and nPCR. Results: A total of 58 participants were included with a median age of 73 years; 64% were male and mean body mass index was 24.6 ± 4.2 kg/m2. LPS correlated with sNox2-dp (rho = 0.420, p = 0.001), whereas sNox2-dp correlated with H2O2 (rho = 0.352, p = 0.007); the LPS–H2O2 association was borderline (rho = 0.259, p = 0.050). sNox2-dp correlated positively with fat-free mass, total body water, ICW, and ICW/h2, whereas LPS correlated with FM (rho = 0.305, p = 0.023). Participants with nPCR > 0.89 g/kg/day had higher LPS concentrations than those with lower nPCR (p = 0.015), and nPCR correlated with ICW/h2 (rho = 0.36, p = 0.007). In multivariable analysis, LPS remained independently associated with FM (β = 0.210, p = 0.046). nPCR was positively associated with ICW/h2 at the threshold of statistical significance (β = 1.393, p = 0.050), whereas sNox2-dp showed a nonsignificant positive trend (p = 0.060). Conclusions: In maintenance hemodialysis, endotoxemia and NOX2 activation showed differential associations with body composition: LPS with adiposity and sNox2-dp with muscularity. Higher nPCR was associated with both greater muscularity and higher LPS concentrations, suggesting a complex relationship between protein intake, the gut–oxidative-stress axis, and body composition.
