Natural products were extracted from traditional Chinese herbal emerging as potential therapeutic drugs for treating cardiovascular diseases. This study examines the role and underlying mechanism of dihydromyricetin (DMY), a natural compound extracted from Ampelopsis grossedentata, in atherosclerosis. DMY treatment significantly inhibits atherosclerotic lesion formation, proinflammatory gene expression and the influx of lesional macrophages and CD4‐positive T cells in the vessel wall and hepatic inflammation, whereas increases nitric oxide (NO) production and improves lipid metabolism in apolipoprotein E‐deficient (Apoe−/−) mice. Yet, those protective effects are abrogated by using NOS inhibitor L‐NAME in Apoe−/− mice received DMY. Mechanistically, DMY decreases microRNA‐21 (miR‐21) and increases its target gene dimethylarginine dimethylaminohydrolase‐1 (DDAH1) expression, an effect that reduces asymmetric aimethlarginine (ADMA) levels, and increases endothelial NO synthase (eNOS) phosphorylation and NO production in cultured HUVECs, vascular endothelium of atherosclerotic lesions and liver. In contrast, systemic delivery of miR‐21 in Apoe−/− mice or miR‐21 overexpression in cultured HUVECs abrogates those DMY‐mediated protective effects. These data demonstrate that endothelial miR‐21‐inhibited DDAH1‐ADMA‐eNOS‐NO pathway promotes the pathogenesis of atherosclerosis which can be rescued by DMY. Thus, DMY may represent a potential therapeutic adjuvant in atherosclerosis management.
Dihydromyricetin, the most abundant natural flavonoid isolated from Ampelopsis grossedentata, exhibits broad anti-tumor effects. However, the effects of dihydromyricetin on cholangiocarcinoma remain unclear. This study examined the anti-tumor effects of dihydromyricetin in two human cholangiocarcinoma cell lines HCCC9810 and TFK-1, and the underlying mechanism was also investigated. Our study was the first to show that dihydromyricetin significantly inhibited cell proliferation, migration, invasion and promoted apoptosis in cholangiocarcinoma cells. By analyzing the TCGA dataset, we found that expression of miR-21, an oncogene and a potential target of anticancer drugs for cholangiocarcinoma, was upregulated in cholangiocarcinoma tissues compared to paired control tissues. Moreover, dihydromyricetin significantly reduced the expression of miR-21 in a dose-dependent manner. Overexpression of miR-21 remarkably abolished the inhibitory effects of dihydromyricetin on cell proliferation, migration, invasion and abrogated its effect of promoting cell apoptosis in both HCCC9810 and TFK-1 cells. Dihydromyricetin remarkably increased the expression of PTEN and decreased the expression of phosphorylated Akt, while overexpression of miR-21 abrogated the modulation of PTEN/ Akt pathway by dihydromyricetin. Taken together, our study demonstrates that dihydromyricetin inhibits cell proliferation, migration, invasion and promotes apoptosis in cholangiocarcinoma cells via regulating miR-21.
Artificial intelligence (AI) is transforming healthcare, yet medical undergraduates often lack adequate AI training. This study systematically evaluated th
The Objective Structured Clinical Examination (OSCE) is a systematic and structured assessment tool that evaluates candidates’ professional medical skills in a simulated environment through a series of time-limited stations. The aim of this meta-analysis was to determine the optimal station number and duration time per station of OSCE to achieve good reliability. A comprehensive search was conducted across PubMed and Embase from inception until August 2024, without language restrictions. Studies were included if they provided data on the station number and duration time of OSCE, along with Cronbach’s alpha. A random-effects model was used to pool the data. A total of 23 studies encompassing 26 Cronbach’s alpha were finally included. Cronbach’s alpha values ranged from 0.43 to 0.93, and 11 studies demonstrated good internal consistency (Cronbach’s alpha ≥ 0.8). The analysis indicated that a design of 5–10 stations, with each station lasting less than 10 min, yielded the best internal consistency (Cronbach’s alpha = 0.88, 95% CI: 0.86, 1.00). This meta-analysis suggests that the station number of OSCE falling in between 5 and 10, with each station time lasting no more than 10 min are likely to yield good reliability and strong internal consistency.
Dihydromyricetin (DMY), a natural flavonoid compound extracted from the stems and leaves of Ampelopsis grossedentata, has been found as a potential therapeutic chemical for treating atherosclerosis. This study explores the underlying mechanism of DMY repressing M1 macrophage polarization in atherosclerosis. We showed that DMY treatment markedly decreased M1 macrophage markers (e.g., Tnf-α and IL-1β) and p65-positive macrophage numbers in the vessel wall of Apoe-deficient (Apoe–/–) mice. Overexpression of miR-9 or knockdown of SIRT1 in macrophages reversed the effect of DMY on M1 macrophage polarization. The data we presented in the study indicate that the miR-9-mediated SIRT1/NF-κB pathway plays a pivotal role in M1 macrophage polarization and is one of the molecular mechanisms underlying the anti-atherosclerosis effects of DMY. We provide new solid evidence that DMY may be explored as a potential therapeutic adjuvant for treating atherosclerosis.
Cholangiocarcinoma (CCA) leads to poor prognosis due to high aggressiveness and common chemoresistance. Dihydromyricetin (DMY), the main bioactive compound isolated from Ampelopsis grossedentata, exhibits broad anti-tumor effects. This study aimed to investigate the inhibitory effect of DMY on CCA tumor growth and epithelial-mesenchymal transition (EMT) and its underlying mechanism in CCA. DMY treatment significantly inhibited cell proliferation and EMT in CCA cell lines. The expression of ZEB1 and vimentin were down-regulated, while the level of E-cadherin was increased after DMY treatment. By analyzing the TCGA dataset, we found that miR-455 expression was significantly downregulated, while the level of ZEB1 was up-regulated in human CCA tumor tissues compared to normal samples. Mechanistic studies showed that ZEB1 was a direct target of miR-455-3p in CCA. Moreover, DMY treatment potently increased miR-455-3p expression and inhibited ZEB1 expression. Inhibition of miR-455-3p expression abolished DMY's inhibitory effects on tumor growth and EMT in both CCA cells and cell-engrafted nude mice. Finally, DMY significantly suppressed the expressions of p-PI3K and p-AKT, while silencing miR-455-3p remarkably abrogated the inhibitory effect. In conclusion, DMY suppresses tumor growth and EMT through regulating miR-455-3p in human cholangiocarcinoma, suggesting a potential option for CCA treatment.