Tempol and silymarin rescue from zinc-induced degeneration of dopaminergic neurons through modulation of oxidative stress and inflammation

The clinical anti-inflammatory effects and underlying mechanisms of silymarin

Inflammatory conditions are key mediators in the progression of various diseases. Silymarin, derived from Silybum marianum seeds and fruits, has shown efficacy in treating a range of liver diseases. The expanding corpus of research on silymarin highlights its promising role in preventing and managing inflammatory conditions and autoimmune without adverse effects. This review discusses the absorption, metabolism, and anti-inflammatory mechanisms of silymarin, exploring its impact on the secretion of inflammatory factors, such as nuclear factor kappa B (NF-κB) pathway, mitogen-activated protein kinase (MAPK) pathway, and antioxidant pathway. We delve into its disease-modifying potential for clinical applications, thereby laying a theoretical foundation for further silymarin research and clinical studies.

Tempol mitigates inflammation, oxidative stress, and histopathological alterations of cadmium-induced parotid gland injury in rats

Cadmium (Cd) is a potent environmental pollutant that causes functional and structural damage to the salivary glands. Tempol (TEM) has powerful antioxidant activity that can potentially preserve organ function.

AIMS

This study was designed to investigate the protective effects of TEM on Cd-induced toxicity in rat parotid salivary glands.

MATERIALS AND METHODS

Twenty-four adult Wistar male rats were randomly assigned to four equal groups: control, TEM (27.5 g/100 ml), Cd (0.6 g/100 ml), and TEM plus Cd (at the same doses). All treatments were dissolved in distilled water and administered subcutaneously four times a week for four weeks. Parotid gland tissues were isolated and subjected to molecular and histo-biochemical assessments.

KEY FINDINGS

TEM exerted a prophylactic effect against Cd-induced toxicity in the parotid glands by controlling inflammation through the downregulation of toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor kappa B/ interleukin-1 beta mRNA expression, upregulation of aquaporin-5 mRNA expression, improvement of the oxidant/antioxidant status in the parotid gland, mitigation of endoplasmic reticulum stress, and repair of the associated histological and ultrastructural abnormalities.

SIGNIFICANCE

TEM protects against Cd-induced toxicity in the parotid glands of rats, attributable at least in part to its anti-inflammatory and antioxidant properties, as well as its ability to inhibit ER stress and facilitate glandular repair. However, the protective effects of TEM did not reach the levels observed in the control group. TEM could be a promising clinical candidate for protecting the salivary glands, particularly in high-risk groups such as workers exposed to Cd and cigarette smokers.

Estrogen-immuno-neuromodulation disorders in menopausal depression

A significant decrease in estrogen levels puts menopausal women at high risk for major depression, which remains difficult to cure despite its relatively clear etiology. With the discovery of abnormally elevated inflammation in menopausal depressed women, immune imbalance has become a novel focus in the study of menopausal depression. In this paper, we examined the characteristics and possible mechanisms of immune imbalance caused by decreased estrogen levels during menopause and found that estrogen deficiency disrupted immune homeostasis, especially the levels of inflammatory cytokines through the ERα/ERβ/GPER-associated NLRP3/NF-κB signaling pathways. We also analyzed the destruction of the blood-brain barrier, dysfunction of neurotransmitters, blockade of BDNF synthesis, and attenuation of neuroplasticity caused by inflammatory cytokine activity, and investigated estrogen-immuno-neuromodulation disorders in menopausal depression. Current research suggests that drugs targeting inflammatory cytokines and NLRP3/NF-κB signaling molecules are promising for restoring homeostasis of the estrogen-immuno-neuromodulation system and may play a positive role in the intervention and treatment of menopausal depression.

Silymarin and Inflammation: Food for Thoughts

Inflammation is a vital defense mechanism, creating hostile conditions for pathogens, preventing the spread of tissue infection and repairing damaged tissues in humans and animals. However, when inflammation resolution is delayed or compromised as a result of its misregulation, the process proceeds from the acute phase to chronic inflammation, leading to the development of various chronic illnesses. It is proven that redox balance disturbances and oxidative stress are among major factors inducing NF-κB and leading to over-inflammation. Therefore, the anti-inflammatory properties of various natural antioxidants have been widely tested in various in vitro and in vivo systems. Accumulating evidence indicates that silymarin (SM) and its main constituent silibinin/silybin (SB) have great potential as an anti-inflammation agent. The main anti-inflammatory mechanism of SM/SB action is attributed to the inhibition of TLR4/NF-κB-mediated signaling pathways and the downregulated expression of pro-inflammatory mediators, including TNF-α, IL-1β, IL-6, IL-12, IL-23, CCL4, CXCL10, etc. Of note, in the same model systems, SM/SB was able to upregulate anti-inflammatory cytokines (IL-4, IL-10, IL-13, TGF-β, etc.) and lipid mediators involved in the resolution of inflammation. The inflammatory properties of SM/SB were clearly demonstrated in model systems based on immune (macrophages and monocytes) and non-immune (epithelial, skin, bone, connective tissue and cancer) cells. At the same time, the anti-inflammatory action of SM/SB was confirmed in a number of in vivo models, including toxicity models, nonalcoholic fatty liver disease, ischemia/reperfusion models, stress-induced injuries, ageing and exercising models, wound healing and many other relevant model systems. It seems likely that the anti-inflammatory activities of SM/SB are key elements on the health-promoting properties of these phytochemicals.

From zinc homeostasis to disease progression: Unveiling the neurodegenerative puzzle

Zinc is a crucial trace element in the human body, playing a role in various physiological processes such as oxidative stress, neurotransmission, protein synthesis, and DNA repair. The zinc transporters (ZnTs) family members are responsible for exporting intracellular zinc, while Zrt- and Irt-like proteins (ZIPs) are involved in importing extracellular zinc. These processes are essential for maintaining cellular zinc homeostasis. Imbalances in zinc metabolism have been linked to the development of neurodegenerative diseases. Disruptions in zinc levels can impact the survival and activity of neurons, thereby contributing to the progression of neurodegenerative diseases through mechanisms like cell apoptosis regulation, protein phase separation, ferroptosis, oxidative stress, and neuroinflammation. Therefore, conducting a systematic review of the regulatory network of zinc and investigating the relationship between zinc dysmetabolism and neurodegenerative diseases can enhance our understanding of the pathogenesis of these diseases. Additionally, it may offer new insights and approaches for the treatment of neurodegenerative diseases.

Evaluating Silymarin Extract as a Potent Antioxidant Supplement in Diazinon-Exposed Rainbow Trout: Oxidative Stress and Biochemical Parameter Analysis

This study aimed to investigate the effects of diazinon on fish, focusing on hepatotoxic biomarkers and the potential protective effects of silymarin supplementation. One hundred eighty rainbow trout were randomly assigned to four groups: control, diazinon exposed (0.1 mg L-1), silymarin supplemented (400 mg kg-1), and diazinon + silymarin. Blood samples and liver tissue were collected after 7, 14, and 21 days of exposure to analyze biochemical parameters and oxidative biomarkers. Diazinon exposure in fish resulted in liver damage, as indicated by increased antioxidant enzyme activities in the hepatocytes. Silymarin showed the potential to mitigate this damage by reducing oxidative stress and restoring enzyme activities. Nevertheless, diazinon increased creatine phosphokinase activity, which may not be normalized by silymarin. Exposure to diazinon increased glucose, triglyceride, and cholesterol levels, whereas total protein, albumin, and globulin levels were significantly decreased in fish. However, silymarin controlled and maintained these levels within the normal range. Diazinon increased creatinine, urea, uric acid, and ammonia contents. Silymarin could regulate creatinine, urea, and uric acid levels while having limited effectiveness on ammonia excretion. Furthermore, diazinon increased malondialdehyde in hepatocytes, whereas administration of silymarin could restore normal malondialdehyde levels. Overall, silymarin showed potential as a therapeutic treatment for mitigating oxidative damage induced by diazinon in fish, but its effectiveness on creatine phosphokinase, glutathione reductase, and ammonia may be limited.