Myricetin (3,3',4',5,5',7-hexahydroxyflavone) prevents ethanol-induced biochemical and inflammatory damage in the liver of Wistar rats

Effects of idebenone and coenzyme Q10 on NLRP3/caspase-1/IL-1β pathway regulation on ethanol-induced hepatotoxicity in rats

Chronic and excessive alcohol consumption leads to liver toxicity. There is a need to investigate effective therapeutic strategies to alleviate alcohol-induced liver injury, which remains the leading cause of liver-related morbidity and mortality worldwide. Therefore here, we looked into and evaluated how ethanol-induced hepatotoxicity was affected by coenzyme Q10 (CoQ10) and its analog, idebenone (IDE), on the NLRP3/caspase-1/IL-1 pathway. Hepatotoxicity induced in rats through the oral administration of gradually increasing dosages of ethanol (from 2 to 6 g/kg/day) over 30 days and the effect of CoQ10 (10 or 20 mg/kg) and IDE (50 or 100 mg/kg) were evaluated. Serum hepatotoxicity markers (ALT, AST, GGT, ALP, and TBIL), tissue oxidative stress markers and the mRNA expressions of IL-1β, IL-18, TGF-β, NF-κB, NLRP3, and caspase-1 were evaluated. Masson's trichrome staining was also used to visualize fibrosis in the liver tissue. The results indicated that ethanol exposure led to hepatotoxicity as well as considerable NLRP3/caspase-1/IL-1β pathway activation. Moreover, CoQ10 or IDE treatment reduced measured parameters in a dosage-dependent manner. Thus, by inhibiting the NLRP3/caspase-1/IL-1 pathway, CoQ10 and IDE can prevent the hepatotoxicity caused by ethanol, although CoQ10 is more effective than IDE. This study will provide insight into new therapeutic avenues that take advantage of the anti-inflammatory and antioxidant properties of CoQ10 and IDE in ethanol-induced liver diseases.

Hovenia dulcis: a Chinese medicine that plays an essential role in alcohol-associated liver disease

Globally, alcohol-associated liver disease (ALD) has become an increased burden for society. Disulfirams, Benzodiazepines (BZDs), and corticosteroids are commonly used to treat ALD. However, the occurrence of side effects such as hepatotoxicity and dependence, impedes the achievement of desirable and optimal therapeutic efficacy. Therefore, there is an urgent need for more effective and safer treatments. Hovenia dulcis is an herbal medicine promoting alcohol removal clearance, lipid-lowering, anti-inflammatory, and hepatoprotective properties. Hovenia dulcis has a variety of chemical components such as dihydromyricetin, quercetin and beta-sitosterol, which can affect ALD through multiple pathways, including ethanol metabolism, immune response, hepatic fibrosis, oxidative stress, autophagy, lipid metabolism, and intestinal barrier, suggesting its promising role in the treatment of ALD. Thus, this work aims to comprehensively review the chemical composition of Hovenia dulcis and the molecular mechanisms involved in the process of ALD treatment.

Effects of fisetin on ethanol-induced rewarding properties in mice

Background: Alcohol use disorder (AUD) is a chronic relapsing disorder associated with compulsive drinking of alcohol. Natural flavonoid fisetin affects a variety of transmitter systems relevant to AUD, such as aminobutyric acid, N-methyl-D-aspartate, and dopamine, as well as peroxisome proliferator-activated receptors.Objectives: This study investigated fisetin's impact on the motivational properties of ethanol using conditioned place preference (CPP) in mice (n = 50).Methods: Mice were conditioned with ethanol (2 g/kg, i.p.) or saline on alternating days for 8 consecutive days and were given intragastric (i.g.) fisetin (10, 20, or 30 mg/kg, i.g.), 45 min before ethanol conditioning. During extinction, physiological saline was injected to the control and ethanol groups, and fisetin was administered to the fisetin groups. To evaluate the effect of fisetin on the reinstatement of ethanol-induced CPP, fisetin was given 45 min before a priming dose of ethanol (0.4 g/kg, i.p.; reinstatement test day).Results: Fisetin decreased the acquisition of ethanol-induced CPP (30 mg/kg, p < .05) and accelerated extinction (20 and 30 mg/kg, p < .05). Furthermore, fisetin attenuated reinstatement of ethanol-induced CPP (30 mg/kg, p < .05).Conclusions: Fisetin appears to diminish the rewarding properties of ethanol, as indicated by its inhibitory effect and facilitation of extinction in ethanol-induced CPP. These findings imply a potential therapeutic application of fisetin in preventing ethanol-seeking behavior, promoting extinction, and reducing the risk of relapse.

Myricetin improves apoptosis after ischemic stroke via inhibiting MAPK-ERK pathway

BACKGROUND

Neuronal apoptosis is the main cause for the disabilities and deaths of patients suffered with stroke. Neuroprotectants are clinically used to reduce neuronal apoptosis in ischemic stroke. However, the current neuroprotectants have multiple limitations. Myricetin is beneficial for multiple neurodegenerative diseases, but the role of myricetin as a neuroprotective agent in ischemic stroke is still not fully understood.

METHODS AND RESULTS

Middle cerebral artery occlusion, Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining and Western blots were used to explore the anti-apoptotic effects of myricetin in vivo. Flow cytometry, Western blots and Ca²⁺ staining were used to study the neuroprotective effects of myricetin in vitro. In this study, we first demonstrated that myricetin reduced neuronal apoptosis after ischemia in vivo and in vitro. And, among the factors of apoptosis after ischemic stroke, excitotoxicity, oxidative stress and inflammation-induced apoptosis can be alleviated by myricetin. Moreover, we further demonstrated that myricetin was able to improve neuronal intrinsic apoptosis by inhibiting the phosphorylation of extracellular signal-regulated kinase in the oxygen and glucose deprivation in vitro.

CONCLUSIONS

Summarily, our results support myricetin as a novel neuroprotectant for the prevention or treatment of ischemic stroke via MAPK-ERK signaling pathway.

Myricetin alleviated hydrogen peroxide-induced cellular senescence of nucleus pulposus cell through regulating SERPINE1

BACKGROUND

Myricetin (MYR) is a common plant flavonoid with antioxidant and anticancer properties. However, the anti-aging effect of MYR on nucleus pulposus cells (NPCs) is still unknown. The study aimed to explore the effect of MYR on the senescence of NPCs.

METHODS

Methyl-thiazolyl tetrazolium assay was used to detect NPCs viability. Senescence level was evaluated by senescence-associated β-galactosidase (SA-β-Gal) staining and the expression levels of P21, P16, IL-6 and IL-8. RNA-Sequencing (RNA-seq) technology was used to identify differentially expressed genes (DEGs) between hydrogen peroxide + MYR (HO + MYR) group and HO group, and Gene Ontology (GO) functional was performed to analyze DEGs. A Venn diagram was generated to screen overlapping DEGs related to aging and inflammation, and the role of the promising validated DEG was selected for further investigation by gene functional assays.

RESULTS

HO inhibited NPCs viability and stimulated the senescent phenotype of NPCs, whereas MYR treatment significantly reversed SA-β-gal activity in NPCs. MYR also reduced the expression of p21 and p16 and the secretion of IL-6 and IL-8 induced by HO. RNA-seq screened 421 DEGs. The GO enrichment results showed DEGs were mainly enriched in terms such as "sterol biosynthetic process". We also found SERPINE1 has the highest log2FC abs. Silence of SERPINE1 inhibited HO-induced NPCs senescence, and overexpression of SERPINE1 could limit the anti-aging effect of MYR.

CONCLUSIONS

MYR alleviated HO-induced senescence of NPCs by regulating SERPINE1 in vitro.