Search Results (1,058)

Heme, an essential prosthetic group involved in mitochondrial respiration and transcriptional regulation, is synthesized via the rate-limiting enzyme 5-aminolevulinic acid synthase (ALAS). Utilizing heterozygous mouse models for ALAS1 and ALAS2, our studies have revealed diverse systemic consequences of chronic heme deficiency. ALAS1-heterozygous (ALAS1+/−) mice develop metabolic dysfunction characterized by insulin resistance, glucose intolerance, and abnormal glycogen accumulation, linked mechanistically to reduced AMP-activated protein kinase (AMPK) signaling. These mice also exhibit pronounced mitochondrial dysfunction, impaired autophagy, and accelerated aging phenotypes, including sarcopenia and metabolic decline, highlighting heme’s role as a critical metabolic regulator. Additionally, ALAS2 heterozygosity (ALAS2+/−) leads to impaired erythropoiesis, resulting in anemia and ineffective iron utilization. Importantly, supplementation with the heme precursor 5-aminolevulinic acid (5-ALA) significantly mitigates ALAS1+/− phenotypes, restoring metabolic function, mitochondrial health, autophagy, and immune competence. This review encapsulates key findings from our group’s research together with advances made by multiple research groups over the past decade, collectively establishing heme homeostasis as a central regulator of systemic physiology and highlighting the therapeutic potential of 5-ALA in treating heme-deficient pathologies. Full article

With increasing interest in natural therapeutic strategies for skin aging, plant-derived compounds have gained attention for their potential to protect against oxidative stress and inflammation. In this study, we investigated the anti-aging and anti-inflammatory effects of flavonoids isolated from Cercidiphyllum japonicum using a tumor necrosis factor-alpha (TNF-α)-stimulated normal human dermal fibroblast (NHDF) model. The aerial parts of C. japonicum were extracted and analyzed by high-performance liquid chromatography (HPLC), leading to the identification of four major compounds: maltol, chlorogenic acid, ellagic acid, and quercitrin. Each compound was evaluated for its antioxidant and anti-aging activities in TNF-α-stimulated NHDFs. Among them, ellagic acid exhibited the most potent biological activity and was selected for further mechanistic analysis. Ellagic acid significantly suppressed intracellular reactive oxygen species (ROS) generation and matrix metalloproteinase-1 (MMP-1) secretion (both p < 0.001), while markedly increasing type I procollagen production (p < 0.01). Mechanistic studies demonstrated that ellagic acid inhibited TNF-α-induced phosphorylation of mitogen-activated protein kinases (MAPKs), downregulated cyclooxygenase-2 (COX-2), and upregulated heme oxygenase-1 (HO-1), a key antioxidant enzyme. Additionally, ellagic acid attenuated the mRNA expression of inflammatory cytokines, including interleukin-6 (IL-6) and interleukin-8 (IL-8), indicating its broad modulatory effects on oxidative and inflammatory pathways. Collectively, these findings suggest that ellagic acid is a promising plant-derived bioactive compound with strong antioxidant and anti-inflammatory properties, offering potential as a therapeutic agent for the prevention and treatment of skin aging. Full article

Oxidative stress significantly contributes to the exacerbation of brain damage during cerebral ischemia-reperfusion injury (CIR/I). In our previous study, purified cornel iridoid glycoside (PCIG), consisting of morroniside (MOR) and loganin (LOG), showed neuroprotective effects against CIR/I. To further explore the antioxidative effects and underlying molecular mechanisms, we applied PCIG, MOR, and LOG to rats injured by middle cerebral artery occlusion/reperfusion (MCAO/R) as well as H₂O₂-stimulated PC12 cells. Additionally, the molecular docking analysis was performed to assess the interaction between the PCIG constituents and Kelch-like ECH-associated protein 1 (Keap1). The results showed that the treated rats experienced fewer neurological deficits, reduced lesion volumes, and lower cell death accompanied by decreased levels of malondialdehyde (MDA) and protein carbonyl, as well as increased activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). In H₂O₂-stimulated PC12 cells, the treatments decreased reactive oxygen species (ROS) production, mitigated mitochondrial dysfunction, and inhibited mitochondrial-dependent apoptosis. Moreover, the treatments facilitated Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) translocation into the nucleus and selectively increased the expression of NAD(P)H quinone oxidoreductase 1 (NQO-1) and heme oxygenase 1 (HO-1) through MOR and LOG, respectively. Both MOR and LOG demonstrated strong binding affinity to Keap1. These findings suggested that PCIG, rather than any individual components, might serve as a valuable treatment for ischemic stroke by activating the Nrf2/NQO-1 and Nrf2/HO-1 signaling pathway. Full article

Large-conductance, voltage- and calcium-activated potassium (BK) channels are crucial regulators of cellular excitability, influenced by various signaling molecules, including heme. The BK channel contains a heme-sensitive motif located at the sequence ⁶¹²CKACH⁶¹⁶, which is a conserved heme regulatory motif (HRM) found in the cytochrome c protein family. This motif is situated within a linker region of approximately 120 residues that connect the RCK1 and RCK2 domains, and it also includes terminal α-helices similar to those found in cytochrome c family proteins. However, much of this region has yet to be structurally defined. We conducted a sequence alignment of the BK linker region with mitochondrial cytochrome c and cytochrome c domains from various hemoproteins to better understand this functionally significant region. In addition to the HRM motif, we discovered that important structural and functional elements of cytochrome c proteins are conserved in the BK RCK1-RCK2 linker. Firstly, the part of the BK region that is resolved in available atomic structures shows similarities in secondary structural elements with cytochrome c domain proteins. Secondly, the Met80 residue in cytochrome c domains, which acts as the second axial ligand to the heme iron, aligns with the BK channel. Beyond its role in electron shuttling, cytochrome c domains exhibit various catalytic properties, including peroxidase activity—specifically, the oxidation of suitable substrates using peroxides. Our findings reveal that the linker region endows human BK channels with peroxidase activity, showing an apparent H₂O₂ affinity approximately 40-fold greater than that of mitochondrial cytochrome c under baseline conditions. This peroxidase activity was reduced when substitutions were made at ⁶¹²CKACH⁶¹⁶ and other relevant sites. These results indicate that the BK channel possesses a novel module similar to the cytochrome c domains of hemoproteins, which may give rise to unique physiological functions for these widespread ion channels. Full article

This study evaluated the inhibitory activity of quercetin at sub-inhibitory concentrations on quorum-sensing (QS) molecules in vitro and the effects of dietary supplementation with quercetin (for 24 consecutive days) on enterotoxigenic Escherichia coli (ETEC)-induced inflammatory and oxidative stress responses in weaned piglets. The piglets were fed one of three diets: the basal diet (Con), ETEC challenge (K88) after the basal diet, or ETEC challenge (quercetin + K88) after the basal diet supplemented with 0.2% quercetin. In vitro experiments revealed that 5 mg/mL quercetin exhibited the strongest QS inhibitory activity and reduced pigment production by Chromobacterium violaceum ATCC12472 by 67.70%. In vivo experiments revealed that quercetin + K88 significantly increased immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) levels in the serum, ileum mucosa, and colon mucosa; increased glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) levels in the serum, liver, and colon mucosa; and decreased cluster of differentiation 3 (CD3) and cluster of differentiation 8 (CD8)activity in the serum compared with K88 alone. Quercetin + K88 significantly alleviated pathological damage to the liver and spleen and upregulated antioxidant genes (nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1(HO-1), CAT, SOD, and glutathione s-transferase (GST)). Inducible nitric oxide synthase (iNOS) and kelch-like ech-associated protein 1 (Keap1), which cause oxidative damage to the liver and spleen, were significantly downregulated. The acetic acid content in the cecum was significantly increased, and the E. coli count and QS signal molecule autoinducer-2 (AI-2) yield were significantly reduced. In conclusion, 0.2% dietary quercetin can alleviate ETEC-induced inflammation and oxidative stress in weaned piglets. Full article

Liver fibrosis remains a critical health concern with limited therapeutic options. Kaempferol (Kae) is a natural flavonoid widely present in natural plants, yet its role in modulating gut–liver axis interactions during fibrosis is unexplored. This study investigates the hepatoprotective effects of Kae on alleviating carbon tetrachloride (CCl₄)-induced liver fibrosis, and its underlying mechanisms, focusing on oxidative stress, gut microbiota, and short-chain fatty acids (SCFAs), are revealed. A mouse model of hepatic fibrosis was built by the subcutaneous injection of CCl₄. Meanwhile, Kae was administered by gavage at doses of 25, 50, and 100 mg/kg body weight. Serum biomarkers, liver histopathology, oxidative damage markers, and nuclear factor erythroid 2-related factor 2 (Nrf2)/kelch-like ECH-associated protein 1 (Keap1)/heme oxygenase 1 (HO-1) signaling were analyzed. AML12 hepatocytes were pretreated with Kae or SCFAs (acetate, propionate, butyrate) before H₂O₂-induced oxidative injury. The changes in gut microbiota and the levels of SCFAs were assessed via 16S rRNA sequencing and GC-MS, respectively. Kae effectively alleviated the destruction of the liver morphology and tissue structure, reduced the infiltration of inflammatory cells, collagen deposition in the liver, and the expression of fibrotic factors, and downregulated the oxidative stress level in the liver of mice with liver fibrosis by activating the Nrf2/Keap1/HO-1 pathway (p < 0.05 or 0.01). In vitro, Kae significantly mitigated H₂O₂-induced cytotoxicity and oxidative damage (p < 0.05 or 0.01). Furthermore, Kae restored gut microbiota diversity, increased beneficial genera (e.g., Lactobacillus), and elevated both intestinal and hepatic SCFA levels (p < 0.01). The discrepant SCFA pretreatment similarly protected AML12 cells by activating Nrf2 signaling (p < 0.05 or 0.01). Our research suggests that Kae could inhibit CCl₄-induced liver fibrosis by restoring the levels of intestinal metabolite SCFAs to reduce oxidative damage. Full article

Nitrogen-containing bisphosphonates (N-BPs) are commonly used drugs in the treatment of bone diseases due to their potent inhibition of the mevalonate pathway, leading to disrupted protein prenylation and reduced osteoclast activity. Although N-BPs are effective in reducing bone resorption, increasing evidence indicates their side effects on various non-skeletal cells. The aim of this review is to synthesize the current knowledge on the cellular and molecular effects of N-BPs outside the skeletal system, with particular emphasis on their impact on mitochondrial function and energy metabolism. At the cellular level, N-BPs may reduce viability, modulate inflammatory responses, trigger apoptosis, disrupt cytoskeletal organization, and influence signaling and energy metabolism. N-BPs may also impair the prenylation of proteins essential for mitochondrial dynamics and quality control, and may disrupt Ca²⁺ homeostasis. As we have shown in endothelial cells, by inhibiting the mevalonate pathway, N-BPs may lead to a reduction in key components of the mitochondrial respiratory chain, such as coenzyme Q (CoQ) and a-heme. These effects can contribute to impaired mitochondrial respiratory function, increased oxidative stress, and mitochondria-dependent apoptosis, affecting cellular energy metabolism and viability. These findings underscore the multifaceted impact of N-BPs beyond bone, emphasizing the importance of mitochondrial health and energy metabolism in understanding their broader biological effects and potential adverse outcomes. Full article

Oxidative stress, which contributes to neuronal cell dysfunction, is a critical factor in the pathogenesis of neurodegenerative diseases. Anthocyanins and α-tocopherol have shown potential in mitigating oxidative damage, and their combination may provide synergistic effects. This study investigated the combined effects of a cyanidin-3-glucoside (C3G)-enriched extract derived from Oryza sativa L. cv. RD83 and α-tocopherol (C3GE) on hydrogen peroxide (H₂O₂)-induced oxidative stress in SH-SY5Y cells. Cells were treated with C3GE during exposure to 200 µM H₂O₂. Cell viability, intracellular reactive oxygen species (ROS), and oxidative stress biomarkers, including the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), as well as malondialdehyde (MDA) levels, were evaluated. Protein expression levels of histone deacetylase 1 (HDAC1), nuclear factor erythroid 2 related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and SOD1 were also assessed. The combined treatment markedly improved cell viability, suppressed ROS accumulation, enhanced antioxidant enzyme activities, and significantly reduced MDA levels, suggesting effective protection against oxidative damage. Mechanistically, C3GE downregulated HDAC1 expression while upregulating Nrf2, HO-1, and SOD1, indicating that its antioxidant and neuroprotective effects are mediated, at least in part, through epigenetic modulation of redox-related signaling pathways. These results demonstrate a synergistic interaction between C3G and α-tocopherol that enhances cellular antioxidant defenses and supports redox homeostasis. In conclusion, the C3GE combination offers a promising therapeutic approach for preventing or attenuating oxidative stress-induced neuronal injury, with potential relevance for the treatment of neurodegenerative disorders. Full article

Local anesthetics (LAs) are frequently administered via peritendinous ultrasound-guided injections for diagnostic and therapeutic purposes. Since in vitro studies have demonstrated LAs’ tenotoxic effects, raising concerns about their safety in infiltrative treatments, and since lidocaine (LD) emerged as one of the most cytotoxic LAs, we analyzed apoptosis, oxidative stress, and collagen turnover pathways in human tenocytes treated with LD, as well as the possible protection from LD-induced injury elicited by antioxidant ascorbic acid (AA). Tenocytes from gluteal tendons were treated with 0.2 and 1 mg/mL LD, or left untreated (CT), and treated with 50 μg/mL or 250 μg/mL AA. Nuclear morphology, cytochrome c expression, and caspase 3 activation were analyzed to study the effect of LD on apoptosis. Heme Oxygenase 1 (HO-1) mRNA and genes and proteins involved in collagen turnover were investigated using molecular approaches. Our results show that 0.2 and 1 mg/mL LD did not induce apoptosis and did not modify collagen synthesis and maturation. Conversely, increased collagen degradation was observed, and AA was not protective against oxidative stress induction in the presence of LD. Our findings suggest that LD does not affect the cell viability of tenocytes and that peritendinous LD injections are safe in this regard. LD-associated collagen degradation and the AA buffer effect are still debatable. Overall, our study contributes to clarifying the effect of LD on tenocytes’ viability and ECM homeostasis and provides new additional information useful for the safe clinical application of this drug and for further analysis. Full article

Elsholtzia blanda (Benth.) Benth. (EBB) is a traditional plant in Nepal with bioactive properties, including antioxidant, cytotoxic, and antitumor activities. In this study, a methanol EBB extract was tested to evaluate the anti-inflammatory effect against lipopolysaccharide (LPS)-induced microglial (BV2) cells. EBB effectively suppressed LPS-induced nitric oxide production and inhibited the secretion of proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. In LPS-stimulated BV2 cells, EBB significantly inhibited inducible nitric oxide synthase (iNOS), TNF-α, IL-6, IL-1β, IL-8, IL-18, and IL-10 mRNA expression in a concentration-dependent manner. In particular, EBB significantly reduced the protein expression of iNOS and cyclooxygenase-2, which were upregulated by LPS. Further, EBB could alleviate the inflammatory response in microglia by suppressing the phosphorylation of mitogen-activated protein kinases. EBB also attenuated LPS-induced reactive oxygen species (ROS) in BV2 cells. In addition, EBB enhanced heme oxygenase-1 (HO-1) protein and mRNA expression. The present results show that an EBB extract could effectively suppress the neuroinflammatory response induced by LPS in BV2 cells. Accordingly, an EBB extract is a promising preventive agent against diseases involving neuroinflammatory responses. Full article

: Negative energy balance (NEB) in dairy cows induces excessive lipolysis, leading to elevated levels of β-hydroxybutyric acid (BHBA), which, when accumulated, can cause liver damage. Rutin (RT), a natural flavonoid with antioxidant and anti-inflammatory properties, has demonstrated potential hepatoprotective effects; however, its ability to mitigate BHBA-induced hepatocellular injury in calves remains unclear. This study first assessed the impact of various BHBA concentrations on oxidative stress in calf hepatocytes, then explored the protective effects and underlying mechanisms of RT, and finally employed untargeted metabolomics to further elucidate RT’s mode of action. The results showed that exposure to 1.2 mM BHBA significantly increased malondialdehyde (MDA), nitric oxide (NO) contents, and reactive oxygen species (ROS) levels, while markedly decreasing glutathione (GSH) content and catalase (CAT) activity compared with the blank control. Notably, pretreatment with 100 μg/mL RT resulted in the greatest increase in GSH contents (180%) compared to BHBA treatment alone, while 150 μg/mL RT led to the most pronounced reduction in MDA contents (220%). Furthermore, BHBA treatment significantly upregulated the expression of Kelch-like ECH-associated protein 1 (Keap1) and downregulated nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone dehydrogenase 1 (NQO1), and heme oxygenase-1 (HO-1) at both the mRNA and protein levels. These alterations were effectively reversed by pretreatment with 100 μg/mL RT. Non-targeted metabolomics identified 1525 metabolites in total. Based on OPLS-DA, metabolites with a variable importance in projection (VIP) > 1 and p < 0.05 were considered significantly altered. Compared with the blank control, BHBA treatment upregulated 47 metabolites—including 8-hydroxy-2′-deoxyguanosine, 3-hydroxyisovaleric acid, and N-palmitoyl-sphingosine—and downregulated 58 metabolites, such as betaine, linolenic acid, and arachidonic acid. In contrast, RT pretreatment upregulated 207 metabolites relative to the BHBA treatment, including linolenic acid, taurocholic acid, and 4-hydroxybenzoic acid, and downregulated 126 metabolites, including 3-hydroxyisovaleric acid, 8-hydroxy-2′-deoxyguanosine, and pyruvaldehyde. Pathway enrichment analysis indicated that RT alleviated BHBA-induced hepatocyte injury primarily by modulating the fatty acid degradation pathway. In summary, RT mitigated BHBA-induced oxidative stress in calf hepatocytes by regulating the Keap1/Nrf2 signaling pathway and further exerted protective effects through metabolic reprogramming. Full article

Methamphetamine (METH) misuse-induced affective and cognitive dysfunctions cause severe global health and economic burdens. However, the mechanisms underlying METH withdrawal-induced negative emotions and cognitive deficits, as well as the treatment strategies for them, remain elusive. Previous findings suggest that METH use triggers neuroinflammation and neuronal apoptosis, and protein kinase B (AKT), forkhead box protein 1 (FOXO1), and heme-oxygenase-1 (HO-1) are implicated in these processes. In the present study, we aimed to reveal the role and potential mechanisms of luteolin, a flavonoid phytochemical with anti-inflammatory and antioxidative properties, in METH withdrawal-induced negative emotions and cognitive deficits. We found that prolonged METH withdrawal led to an increase in neuronal activity and a decrease in the protein expression of phosphorylated AKT (p-AKT) and HO-1 in the prefrontal cortex (PFC) and caudate putamen (CPu). Luteolin pretreatment partially mitigated these METH withdrawal-induced negative emotions and cognitive deficits, and prevented the abnormal activation of PFC and CPu as well as the downregulation of AKT/HO-1 expression. Notably, we further observed that luteolin inhibited the METH-induced nuclear translocation of FOXO1. Our findings suggest that luteolin may alleviate METH withdrawal-induced affective and cognitive dysfunctions by reducing oxidative injury in the brain through the AKT/FOXO1/HO-1 pathway, highlighting its potential for treating drug addiction-related health issues. Full article

Serratia plymuthica, isolated from the midgut of Aedes aegypti, displays remarkable resilience to hemin, a toxic hemoglobin byproduct generated during blood digestion. This study explores its proteomic adaptations under oxidative stress induced by 5 mM hemin, mimicking midgut conditions. Growth assays demonstrated that S. plymuthica tolerated hemin concentrations ranging from 5 µM to 1 mM, reaching the stationary phase within approximately 10 h. Colonies exhibited morphological changes—darkened peripheries and translucent halos—suggesting heme accumulation and detoxification. Label-free quantitative proteomics identified 436 proteins, among which 28 were significantly upregulated—including universal stress proteins (USPs), ABC transporters, and flavodoxin—while 54 were downregulated, including superoxide dismutase and several ribosomal proteins. Upregulated proteins were associated with antioxidant defense, heme transport, and redox regulation, whereas downregulated proteins suggested metabolic reprogramming to conserve energy under stress. Functional enrichment analysis revealed significant alterations in transmembrane transport, oxidative stress response, and central metabolism. These findings suggest that S. plymuthica contributes to redox homeostasis in the mosquito gut by mitigating reactive oxygen species (ROS) and detoxifying excess heme, supporting its role as a beneficial symbiont. The observed stress tolerance mechanisms may influence mosquito physiology and vector competence, offering novel insights into mosquito–microbiota interactions and potential microbiota-based strategies for vector control. Full article

Meloxicam has been identified as an adjuvant therapeutic component in the management of bovine uterine diseases, exhibiting anti-inflammatory and antioxidant effects. However, the mechanisms underlying its antioxidant actions in the context of bovine uterine diseases remain incompletely understood. The objective of this research was to determine whether meloxicam exerts its antioxidant effects through the Nrf2/HO-1 signaling pathway. By employing N-acetylcysteine (NAC), a scavenger of reactive oxygen species (ROS), along with inhibitors directed against heme oxygenase-1 (HO-1) or nuclear factor erythroid 2-related factor 2 (Nrf2), we investigated the dynamic changes in oxidative stress markers (ROS and malondialdehyde) and antioxidant indices (comprising catalase, superoxide dismutase, and glutathione), as well as the expression profiles of Nrf2 and inflammation-associated genes and proteins in bovine endometrial epithelial cells (BEECs) subjected to lipopolysaccharide (LPS) stimulation. As a result, meloxicam alleviated the LPS-induced elevation of oxidative stress marker levels and the reduction in antioxidant enzyme activities and antioxidant substance contents in BEECs. Compared to NAC, meloxicam demonstrated superior efficacy in activating the Nrf2 pathway, with the promotion of NRF2 expression (~1.6-fold) and nuclear translocation. The pretreatment of cells with HO-1 or Nrf2 inhibitors markedly attenuated the antioxidant activity of meloxicam. In summary, meloxicam primarily alleviates LPS-induced oxidative stress through the activation of the Nrf2/HO-1 pathway in BEECs. Full article

Prolonged exposure to ultraviolet (UV) radiations represents a significant risk factor and may lead to various skin disorders, premature aging, and an increased susceptibility to skin cancers. Recently, probiotics have emerged as promising candidates for fortifying the skin’s natural defences through their diverse mechanisms. The aim of the present work was exploring the potential of five heat-treated probiotics (Skinbac^TM, Probiotical Research S.r.l., Novara, Italy), as protective agents against UVA and UVB damages on human keratinocyte line (HaCaT) and human skin 3D model (Phenion^® Full-Thickness Skin Model, Henkel AG & Co. KGaA, Dusseldorf, Germany). The protective role toward artificially induced oxidative stress was evaluated by determining the residual viability after UV exposure and analyzing gene expression of markers involved in apoptosis (Tumor protein 53), inflammation/immunosuppression (Interleukin 6), oxidative stress (oxidative stress response enzyme heme oxygenase 1), investigated using quantitative real-time PCR. Additionally, we examined the protective effects of these strains, testing them on Normal Human Epidermal Keratinocytes (NHEK) irradiated with UVC, specifically, evaluating the expression of tight junction proteins, including claudin 1, claudin 4, and occludin, by ELISA. The tested heat-treated probiotics effectively protected from UVA, UVB, and UVC damage on all end points analyzed, revealing their capacity to enhance barrier protection in cases of damage and their potential for innovative skincare strategies centered around probiotic-based formulations for enhanced protection against UV-induced skin damage. Full article