Tyrosol attenuates NASH features by reprogramming the hepatic immune milieu

Tyrosol ameliorates depressive-like behavior and hippocampal damage in perimenopausal depression rats by inhibiting oxidative stress and thyroid dysfunction

Perimenopausal depression (PMD) is a common condition during the female perimenopausal period. Tyrosol represents a promising neuroprotective agent. This study aims to determine if tyrosol alleviate PMD progression. A rat model of PMD was established using bilateral ovariectomy and chronic unpredictable mild stress. Behavioral tests showed that tyrosol alleviated the depressive-like behavior in PMD rats. Tyrosol increased sucrose preference in SPT and residence time in the central region of OFT, and reduced immobility time in FST of PMD rats. Apoptosis of neurons in the hippocampus of PMD rats was inhibited by tyrosol treatment, as evidenced by an increase in the protein expression of Bcl-2 and a decrease in the expression of Bax and cleaved caspase-3 in hippocampal tissue. Tyrosol treatment effectively reduced thyroid-stimulating hormone levels and elevated the levels of free triiodothyronine and free thyroxine in the serum of PMD rats. The levels of ROS and MDA were decreased, and the levels of GPX and SOD were increased in the hippocampal tissue of PMD rats by tyrosol treatment. In addition, tyrosol treatment promoted the levels of brain-derived neurotrophic factor (BDNF) and monoamine neurotransmitters (5-HT, DA, and NA) in the hippocampal tissue. In summary, tyrosol might ameliorate depression-like behavior in PMD rats by inhibiting hippocampal oxidative stress and damage and promoting monoamine neurotransmitter release, and restoration of thyroid function may also be involved.

Synthesis and Health Effects of Phenolic Compounds: A Focus on Tyrosol, Hydroxytyrosol, and 3,4-Dihydroxyacetophenone

Tyrosol (Tyr), hydroxytyrosol (TH), and 3,4-Dihydroxyacetophenone (3,4-DHAP) are three phenolic compounds naturally present in plants that have attracted considerable research attention due to their potent antioxidant, anti-inflammatory, anticancer, and cardiovascular protective properties. In recent years, mounting evidence has indicated that these phenolic compounds hold broad potential in both disease prevention and treatment. This paper reviews the chemical structures and synthetic methods of Tyr, HT, and 3,4-DHAP, as well as their multifaceted effects on human health, particularly their roles and mechanisms in antioxidation, anti-inflammation, cardiovascular protection, neuroprotection, and anticancer activity. In addition, this paper explores the future prospects of these compounds and the current challenges associated with their application-such as low bioavailability and long-term safety concerns-and proposes directions for further investigation.

Extra virgin olive oil mitigates lung injury in necrotizing enterocolitis: Effects on TGFβ1, Caspase-3, and MDA in a neonatal rat model

BACKGROUND

Necrotizing enterocolitis (NE), which is common in premature babies, has been associated with lung damage. Our aim is to explore the effect of enterally administered extra virgin olive oil (EO) with rich polyphenol content on clinical parameters, histopathological score, Transforming growt factor beta-1 (TGFβ1), Caspase 3 and Malondialdehyde (MDA) levels in NE-related lung injury of neonatal rats.

METHODS

Three groups (control, NE, NE+EO) were created, with 8 neonatal rats in each group. NE was induced by hypoxia-hyperoxia-hypothermia and formula feeding. EO was given to the treatment group by orogastric probe for 3 days. Intestinal and lung tissue were excised for analysis.

RESULTS

TGFβ1 expression levels, TGFβ1 and MDA concentration levels were higher in the NE compared to NE +  EO and control groups (p < 0.001), and their levels decreased after EO treatment compared to the NE group (p < 0.001). It was determined that EO treatment significantly reduced the histopathological damage and the caspase-3 (CASP3) expression level in the lung (p < 0.001).

CONCLUSION

Our findings emphasize that TGFß1 has an crucial function in NE-related lung injury and that EO has therapeutic potential in NE-related lung injury.

Inflammation unleashed: The role of pyroptosis in chronic liver diseases

Pyroptosis, a newly identified form of programmed cell death intertwined with inflammatory responses, is facilitated by the Gasdermin family's pore-forming activity, leading to cell lysis and the release of pro-inflammatory cytokines. This process is a double-edged sword in innate immunity, offering protection against pathogens while risking excessive inflammation and tissue damage when dysregulated. Specifically, pyroptosis operates through two distinct signaling pathways, namely the Caspase-1 pathway and the Caspase-4/5/11 pathway. In the context of chronic liver diseases like fibrosis and cirrhosis, inflammation emerges as a central contributing factor to their pathogenesis. The identification of inflammation is characterized by the activation of innate immune cells and the secretion of pro-inflammatory cytokines such as IL-1α, IL-1β, and TNF-α. This review explores the interrelationship between pyroptosis and the inflammasome, a protein complex located in liver cells that recognizes danger signals and initiates Caspase-1 activation, resulting in the secretion of IL-1β and IL-18. The article delves into the influence of the inflammasome and pyroptosis on various liver disorders, with a specific focus on their molecular and pathophysiological mechanisms. Additionally, the potential therapeutic implications of targeting pyroptosis for liver diseases are highlighted for future consideration.

Recent Advances in miRNA-Based Therapy for MASLD/MASH and MASH-Associated HCC

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a growing health concern worldwide, affecting more than 1 billion adults. It may progress to metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and ultimately hepatocellular carcinoma (HCC). Emerging evidence has demonstrated the role in this transition of microRNAs (miRNAs), which regulate the expression of genes associated with lipid metabolism, inflammation, fibrosis, and cell proliferation. Specific miRNAs have been identified to exacerbate or mitigate fibrotic and carcinogenic processes in hepatic cells. The modulation of these miRNAs through synthetic mimics or inhibitors represents a promising therapeutic strategy. Preclinical models have demonstrated that miRNA-based therapies can attenuate liver inflammation, reduce fibrosis, and inhibit tumorigenesis, thus delaying or preventing the onset of HCC. However, challenges such as delivery mechanisms, off-target effects, and long-term safety remain to be addressed. This review, focusing on recently published preclinical and clinical studies, explores the pharmacological potential of miRNA-based interventions to prevent MASLD/MASH and progression toward HCC.

Beneficial Effects of Tyrosol and Oleocanthal from Extra Virgin Olive Oil on Liver Health: Insights into Their Mechanisms of Action

The Mediterranean diet and consumption of EVOO are associated with multiple beneficial effects for human health, e.g. reduction in cardiovascular risk and mortality, improvement in the lipid profile, and the prevention of chronic diseases, such as cancers and neurodegenerative diseases. In EVOO, more than 30 different phenolic-derived compounds have been identified, representing one of the most promising bioactive classes in olive oil. This review explores the hepatoprotective properties of two of these compounds, tyrosol and oleocanthal, focusing on their mechanisms of action. Recent studies have shown that these compounds, which share a similar chemical structure with a hydroxyl group attached to an aromatic hydrocarbon ring, can potentially mitigate chronic liver diseases, such as MASLD and liver fibrosis, as well as their progression to liver cancer. Consequently, they deserve attention for future pharmacological drug development. In vitro and in vivo studies have suggested that these compounds exert these effects through the regulation of cellular pathways involved in antioxidant response, lipid metabolism, transcription factor activity, and NF-κB signaling. Understanding the mechanisms underlying the hepatoprotective properties of tyrosol and oleocanthal may provide valuable information for the development of therapeutic agents based on their chemical structures capable of targeting chronic liver diseases.

Oxidative Stress as a Target for Non-Pharmacological Intervention in MAFLD: Could There Be a Role for EVOO?

Oxidative stress plays a central role in most chronic liver diseases and, in particular, in metabolic dysfunction-associated fatty liver disease (MAFLD), the new definition of an old condition known as non-alcoholic fatty liver disease (NAFLD). The mechanisms leading to hepatocellular fat accumulation in genetically predisposed individuals who adopt a sedentary lifestyle and consume an obesogenic diet progress through mitochondrial and endoplasmic reticulum dysfunction, which amplifies reactive oxygen species (ROS) production, lipid peroxidation, malondialdehyde (MDA) formation, and influence the release of chronic inflammation and liver damage biomarkers, such as pro-inflammatory cytokines. This close pathogenetic link has been a key stimulus in the search for therapeutic approaches targeting oxidative stress to treat steatosis, and a number of clinical trials have been conducted to date on subjects with NAFLD using drugs as well as supplements or nutraceutical products. Vitamin E, Vitamin D, and Silybin are the most studied substances, but several non-pharmacological approaches have also been explored, especially lifestyle and diet modifications. Among the dietary approaches, the Mediterranean Diet (MD) seems to be the most reliable for affecting liver steatosis, probably with the added value of the presence of extra virgin olive oil (EVOO), a healthy food with a high content of monounsaturated fatty acids, especially oleic acid, and variable concentrations of phenols (oleocanthal) and phenolic alcohols, such as hydroxytyrosol (HT) and tyrosol (Tyr). In this review, we focus on non-pharmacological interventions in MAFLD treatment that target oxidative stress and, in particular, on the role of EVOO as one of the main antioxidant components of the MD.

NLRP3 Inflammasome in Acute and Chronic Liver Diseases

NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) is an intracellular complex that upon external stimuli or contact with specific ligands, recruits other components, forming the NLRP3 inflammasome. The NLRP3 inflammasome mainly mediates pyroptosis, a highly inflammatory mode of regulated cell death, as well as IL-18 and IL-1β production. Acute and chronic liver diseases are characterized by a massive influx of pro-inflammatory stimuli enriched in reactive oxygen species (ROS) and damage-associated molecular patterns (DAMPs) that promote the assemblage and activation of the NLRP3 inflammasome. As the major cause of inflammatory cytokine storm, the NLRP3 inflammasome exacerbates liver diseases, even though it might exert protective effects in regards to hepatitis C and B virus infection (HCV and HBV). Here, we summarize the current knowledge concerning NLRP3 inflammasome function in both acute and chronic liver disease and in the post liver transplant setting, focusing on the molecular mechanisms involved in NLRP3 activity.