Antioxidants

The feeding of domestic animals with diets in which polyphenols are present is increasingly attracting the attention of nutritionists and scientists. This review summarizes the knowledge regarding polyphenols’ possible positive and negative effects and their bioavailability. The bioavailability of substances is a prerequisite for any postabsorption effect in vivo. Positive and negative properties have been confirmed in previous studies on the diets of domestic animals rich in polyphenols, such as secondary metabolites of plants. Free radicals are formed in every organism, leading to oxidative stress. Free radicals are highly reactive molecules and can react in cells with macromolecules and can cause damage, including in reproductive cells. Some polyphenols at specific concentrations have antioxidant properties that positively affect animal reproduction by improving the quality of male and female gametes. The intake of phytoestrogens that mimic estrogen function can induce various pathological conditions in the female reproductive tract, including ovarian, fallopian, and uterine dysfunction. The metabolism of genistein and daidzein yields the metabolites equol and p-phenyl-phenol, leading to a decline in cow fertilization. The findings so far confirm that numerous questions still need to be answered. This review points out the importance of using polyphenols that have both benificial and some unfavorable properties in specific diets. Full article

Cold tolerance is improved by cold stress acclimation (CS-ACC), and the cold tolerance level is ‘remembered’ by plants. However, the underlying signaling mechanisms remain largely unknown. Here, the CS memory mechanism was studied by bioinformation, plant physiological and photosynthetic parameters, and gene expression. We found that CS-ACC induced the acquisition of CS memory and enhanced the maintenance of acquired cold tolerance (MACT) in cucumber seedlings. The H₂O₂ content and NADPH oxidase activity encoded by CsRBOH was maintained at higher levels during recovery after CS-ACC and inhibition of RBOH-dependent signaling after CS-ACC resulted in a decrease in the H₂O₂ content, NADPH oxidase activity, and MACT. CsRBOH2, 3, 4, and 5 showed high expression during recovery after CS-ACC. Many BZR-binding sites were identified in memory-responsive CsRBOHs promoters, and CsBZR1 and 3 showed high expression during recovery after CS-ACC. Inhibition of RBOH-dependent signaling or brassinosteroids affected the maintenance of the expression of these memory-responsive CsRBOHs and CsBZRs. The photosynthetic efficiency (PE) decreased but then increased with the prolonged recovery after CS-ACC, and was higher than the control at 48 h of recovery; however, inhibition of RBOH-dependent signaling resulted in a lower PE. Further etiolated seedlings experiments showed that a photosynthetic capacity was necessary for CS memory. Therefore, photosynthesis mediated by RBOH-dependent signaling is essential for CS memory. Full article

Pleurotus ostreatus (Jacq.) P. Kumm is cultivated worldwide, and its growth is seriously threatened by heat stress. Here, we performed a comprehensive analysis to investigate the influence of the phytohormone salicylic acid (SA) in P. ostreatus under HS. The results showed that the hyphal growth recovery rate and the antioxidant capacity of P. ostreatus increased with exogenous SA application (0.01 mmol/L and 0.05 mmol/L) after HS treatment. Metabolomic and transcriptomic analyses showed that SA application (0.05 mmol/L) weakened central carbon metabolism to allow cells to survive HS efficiently. In addition, SA shifted glycolysis to one-carbon metabolism to produce ROS scavengers (GSH and NADPH) and reduced ROS production by altering mitochondrial metabolism. SA also maintained nucleotide homeostasis, led to membrane lipid remodeling, activated the MAPK pathway, and promoted the synthesis of cell-wall components. This study provides a reference for further study of SA in microorganisms. Full article

β-thalassemia and sickle cell disease (SCD) are inherited hemoglobinopathies that result in both quantitative and qualitative variations in the β-globin chain. These in turn lead to instability in the generated hemoglobin (Hb) or to a globin chain imbalance that affects the oxidative environment both intracellularly and extracellularly. While oxidative stress is not among the primary etiologies of β-thalassemia and SCD, it plays a significant role in the pathogenesis of these diseases. Different mechanisms exist behind the development of oxidative stress; the result of which is cytotoxicity, causing the oxidation of cellular components that can eventually lead to cell death and organ damage. In this review, we summarize the mechanisms of oxidative stress development in β-thalassemia and SCD and describe the current and potential antioxidant therapeutic strategies. Finally, we discuss the role of targeted therapy in achieving an optimal redox balance. Full article

Polyphenols sourced from Ilex latifolia Thunb. (PIT) contain high levels of phenolic acids, tannic acids, triterpenoids and so on, which play important roles in antioxidant function. This study was conducted to investigate the effects of PIT against intestinal injury in piglets under oxidative stress. Thirty-two weanling piglets were arranged by a 2 × 2 factorial experiment with diets (basal diet vs. PIT diet) and oxidative stress (saline vs. diquat). All piglets were injected with saline or diquat on d 21, respectively. After 7 days, all pigs were slaughtered and intestinal samples were collected. PIT enhanced jejunal villus heights and crypt depth in the piglets under oxidative stress. PIT increased the activities of intestinal mucosal lactase, sucrase and maltase in the challenged piglets. PIT also increased the jejunal ratio of protein to DNA and ileal protein content. PIT increased the jejunal activities of GSH-PX and GSH content and reduced the ileal MDA amounts. Furthermore, PIT regulated the expression of ferroptosis mediators, such as TFR1, HSPB1, SLC7A11 and GPX4. These results indicate that dietary PIT supplementation enhances the histological structure and function of the intestinal mucosa, which is involved in modulating antioxidant capacity and ferroptosis. Full article

There is a marked increase in oxidative stress in the lungs of patients with COPD, as measured by increased exhaled 8-isoprostane, ethane, and hydrogen peroxide in the breath. The lung may be exposed to exogenous oxidative stress from cigarette smoking and indoor or outdoor air pollution and to endogenous oxidative stress from reactive oxygen species released from activated inflammatory cells, particularly neutrophils and macrophages, in the lungs. Oxidative stress in COPD may be amplified by a reduction in endogenous antioxidants and poor intake of dietary antioxidants. Oxidative stress is a major driving mechanism of COPD through the induction of chronic inflammation, induction of cellular senescence and impaired autophagy, reduced DNA repair, increased autoimmunity, increased mucus secretion, and impaired anti-inflammatory response to corticosteroids. Oxidative stress, therefore, drives the pathology of COPD and may increase disease progression, amplify exacerbations, and increase comorbidities through systemic oxidative stress. This suggests that antioxidants may be effective as disease-modifying treatments. Unfortunately, thiol-based antioxidants, such as N-acetylcysteine, have been poorly effective, as they are inactivated by oxidative stress in the lungs, so there is a search for more effective and safer antioxidants. New antioxidants in development include mitochondria-targeted antioxidants, NOX inhibitors, and activators of the transcription factor Nrf2, which regulates several antioxidant genes. Full article

Selenium nanoparticles (SeNPs) are a novel elemental form selenium and often reported to possess beneficial bioactivities such as anticancer, promoting bone growth and immunomodulation. Our previous study demonstrated that chitosan-stabilized SeNPs have strong activity in immunomodulation. However, the mechanism underlying the immunomodulation of SeNPs is still unknown. The aim of this study is to identify the molecular mechanisms involved in SeNP-induced immunomodulation. Using zebrafish, as a common immunological animal model with a highly conserved molecular mechanism with other vertebrates, we conducted serum proteomic and tissue transcriptome analyses on individuals fed with SeNP in healthy or disease conditions. We also compared differences between SeNPs and an exogenous antioxidant Trolox in immune activity and redox regulation. Our results suggest that the immunomodulation activity was highly related to antioxidant activity and lipid metabolism. Interestingly, the biological functions enhanced by SeNP were almost identical in the healthy and disease conditions. However, while the SeNP was suppressing ROS in healthy individuals, it promoted ROS formation during disease condition. This might be related to the defense mechanism against pathogens. SOD and NFkβ appeared to be the key molecular switch changing effect of SeNPs when individuals undergo infection, indicating the close relationship between immune and redox regulation. Full article

Morin is a naturally occurring flavonoid with anti-inflammatory and antioxidative properties. Therefore, we hypothesized that morin may prevent inflammatory bone loss by reducing oxidative stress. To investigate the effect of morin on inflammatory bone loss, mice were injected with lipopolysaccharide (LPS). Osteoclasts (OCs) were analyzed by tartrate-resistant acid phosphatase (TRAP) staining and actin ring formation. Micro-computerized tomography analysis indicated that morin prevented LPS-induced bone loss in mice. In vivo TRAP staining indicated that morin decreased the number and surface of the OCs that were increased in LPS-treated mice. Furthermore, in vitro experiments indicated that morin decreased the number and activity of OCs upon LPS stimulation. Morin decreased actin ring-containing OCs with decreased activation of c-Src (Y416)/vav guanine nucleotide exchange factor 3/Ras-related C3 botulinum toxin substrate 1 compared with LPS alone. Morin decreased cytosolic reactive oxygen species (ROS), thus preventing the oxidation of Src homology region 2 domain-containing phosphatase 1 (SHP-1), followed by the inactivation of c-Src via direct interaction with SHP1. Conversely, SHP1 knockdown abolished the inhibitory effect of morin on OCs. Therefore, our findings suggest that morin disrupted cytoskeletal reorganization via an ROS/SHP1/c-Src axis in OCs, thereby granting protection from LPS-induced bone loss, which demonstrates its therapeutic potential against inflammatory bone loss. Full article

18β-Glycyrrhetinic acid is a nutraceutical agent with promising hepatoprotective effects. Its protective mechanisms against cholestatic liver injury were further investigated in a rodent model of extrahepatic cholestasis caused by Bile Duct Ligation (BDL) in rats. The daily oral administration of 18β-Glycyrrhetinic acid improved liver histology, serum biochemicals, ductular reaction, oxidative stress, inflammation, apoptosis, impaired autophagy, and fibrosis. 18β-Glycyrrhetinic acid alleviated the BDL-induced hepatic and systemic retention of bile acids, matrix-producing cell activation, hepatic collagen deposition, Transforming Growth Factor beta-1/Smad activation, malondialdehyde elevation, glutathione reduction, High Mobility Group Box-1/Toll-Like Receptor-4 activation, NF-κB activation, inflammatory cell infiltration/accumulation, Interleukin-1β expression, Signal Transducer and Activator of Transcription-1 activation, Endoplasmic Reticulum stress, impairment autophagy, and caspase 3 activation. Conversely, the protein expression of Sirt1, Farnesoid X Receptor, nuclear NF-E2-Related Factor-2, Transcription Factor EB, bile acid efflux transporters, and LC3-II, as well as the protein phosphorylation of AMP-Activated Protein Kinase, was promoted in 18β-Glycyrrhetinic acid-treated BDL rats. The hepatoprotective effects of 18β-Glycyrrhetinic acid in the present investigation correlated well with co-activation and possible interactions among Sirt, FXR, and Nrf2. The concurrent or concomitant activation of Sirt1, FXR, and Nrf2 not only restored the homeostatic regulation of bile acid metabolism, but also alleviated oxidative stress, inflammation, apoptosis, impaired autophagy, and fibrosis. Full article

Silencing of DHHC3, an acyltransferase enzyme in the DHHC family, extensively upregulates oxidative stress (OS). Substrates for DHHC3-mediated palmitoylation include several antioxidant proteins and many other redox regulatory proteins. This helps to explain why DHHC3 ablation upregulates OS. DHHC3 also plays a key role in cancer. DHHC3 ablation leads to diminished xenograft growth of multiple cancer cell types, along with diminished metastasis. Furthermore, DHHC3 protein is upregulated on malignant/metastatic cancer samples, and upregulated gene expression correlates with diminished patient survival in several human cancers. Decreased primary tumor growth due to DHHC3 ablation may be partly explained by an elevated OS → senescence → innate immune cell recruitment mechanism. Elevated OS due to DHHC3 ablation may also contribute to adaptive anticancer immunity and impair tumor metastasis. In addition, DHHC3 ablation disrupts antioxidant protection mechanisms, thus enhancing the efficacy of OS-inducing anticancer drugs. A major focus has thus far been on OS regulation by DHHC3. However, remaining to be studied are multiple DHHC3 substrates that may affect tumor behavior independent of OS. Nonetheless, the currently established properties of DHHC3 make it an attractive candidate for therapeutic targeting in situations in which antioxidant protections need to be downmodulated, and also in cancer. Full article

This paper evaluated the chemical and biological properties of bee pollen samples from Romania. Firstly, the bee pollen alcoholic extracts (BPEs) were obtained from raw bee pollen harvested by Apis mellifera carpatica bees. The chemical composition of BPE was obtained by determination of total phenol content and total flavonoid content, UHPLC-DAD-ESI/MS analysis of phenolic compounds, and GC-MS analysis of fatty acids, esters, and terpenes. Additionally, the antioxidant activity was evaluated by the Trolox Equivalent Antioxidant Capacity method. Furthermore, the biological properties of BPE were evaluated (antimicrobial and cytotoxic activity). The raw BP samples studied in this paper had significant phenolic acid and flavonoid content, and moderate fatty acid, ester, and terpene content. P1, P2, and P4 have the highest TPC and TFC levels, and the best antioxidant activity. All BPEs studied had antimicrobial activity on pathogenic strains isolated from the clinic or standard strains. A synergistic antimicrobial effect of the BPEs was observed along with the soluble compounds of L. rhamnosus MF9 and E. faecalis 2M17 against some pathogenic (clinical) strains and, considering the tumour proliferation inhibitory activity, makes BP a potential prebiotic and antitumour agent for the gut environment. Full article

In order to mitigate the detrimental impact that climate change is having on plants, the study of new practices that allow for the reduction of such effects has become imperative. In addition, the revaluation of the promotion of healthy plant by-products has also markedly increased in importance in recent years. In this work, the modifications in biomass and some antioxidant compounds of cauliflower by-products treated with putrescine under extreme temperatures in two different CO₂ scenarios (the control (400 ppm) and a high concentration of CO₂ (1000 ppm)) were studied. Additionally, the compositions of inner and outer leaves were also compared. According to results found in this work, cauliflower grown under elevated CO₂ and treated with putrescine (2.5 mM) prior to heat stress showed the highest biomass accumulation (20%) compared to the control. Moreover, in the outer leaves from cauliflower grown under elevated CO₂ and treated with putrescine prior to high temperature exposure, the highest biosynthesis of sugars (20%) was recorded. Although cauliflower by-products turned out to be rich in polyamines (208.6 nmoles g⁻¹ fresh weight (FW) and 124.3 nmoles g⁻¹ FW for outer and inner leaves, respectively) and phenolic compounds (1070.2 mg gallic acid equivalents ( (GAE) 100 g⁻¹ FW in outer leaves and 772.0 mg GAE 100 g⁻¹ FW in inner leaves), it was the outer leaves that after applying the new strategy showed the greatest increase in polyamines (68%) and phenolic compounds (39%), obtaining here the highest increase in antioxidant activity (3%). Thus, they should no longer be regarded as mere by-products and should be used for pharmaceutical or nutraceutical purposes. The novel strategy presented in this work may allow us to take advantage of both the continued increase in CO₂ and heat waves that are becoming more frequent. Full article