Effects of myricetin against cadmium-induced neurotoxicity in PC12 cells

The roles of MicroRNAs in cadmium toxicity and in the protection offered by plant food-derived dietary phenolic bioactive substances against cadmium-induced toxicity

Cadmium, a harmful food contaminant, poses severe health risks. There are ongoing efforts to reduce cadmium pollution and alleviate its toxicity, including plant-based dietary intervention. This review hypothesizes that microRNAs (miRNAs), as regulatory eukaryotic transcripts, play crucial roles in modulating cadmium-induced organ damage, and plant food-derived bioactive compounds provide protective effects via miRNA-mediated mechanisms. The review reveals that there are interplays between certain miRNAs and plant food-derived dietary bioactive substances when these bioactives, especially phenolics, counteract cadmium toxicity through regulating physiologic and pathologic events (including oxidative stress, apoptosis, autophagy and inflammation). The review discusses common miRNA-associated physiologic/pathologic events and signal pathways shared by the cadmium toxicity and dietary intervention processes. This paper identifies the existing knowledge gaps and potential future work (e.g. joint actions between miRNAs and other noncoding RNAs in the fights against cadmium). The insights provided by this review can improve food safety strategies and public health outcomes.

Evaluating the protective effect of metformin against diclofenac-induced oxidative stress and hepatic damage: In vitro and in vivo studies

Diclofenac (DIC) is one of the most commonly prescribed non-steroidal anti-inflammatory drugs and has been shown to cause oxidative stress and liver injury. The current study investigated protective effects of metformin against DIC-induced hepatic toxicity in both in vitro and in vivo models. For the in vitro study, HepG2 cells were exposed to DIC in the presence or absence of metformin. The effect of metformin on cell viability was evaluated by MTT assay. Oxidative stress parameters (malondialdehyde (MDA), total thiol molecules (TTM), and total antioxidant capacity (TAC)) were assessed. For the in vivo study, thirty-six male Wistar rats were randomly divided into 6 groups. These groups were normal saline, metformin (200 mg/kg), DIC (50 mg/kg/day), DIC + metformin (50, 100, and 200 mg/kg/day). Histopathological studies and serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), albumin, direct and total bilirubin were measured. Also, oxidative stress parameters were assessed in liver tissue. Furthermore, expression of glutathione peroxidase (GPX)-1, -3, and -4, catalase (CAT), superoxide dismutase (SOD)-1, and -3 was examined using the real-time PCR method in hepatic tissue. In the in vitro study, metformin significantly prevented DIC-induced loss in cell viability in HepG2 cells. Metformin markedly reduced DIC-induced elevation of MDA levels and increased the TAC and TTM levels. In the in vivo study, metformin significantly prevented DIC-induced changes in hematological and histological markers. Administration of metformin significantly improved oxidative stress parameters in liver tissue. In addition, metformin increased the expression of antioxidant enzymes. Our results suggest that metformin exerts a significant protective effect against DIC-induced hepatic toxicity.

Lead and cadmium co-exposure modified PC12 viability and ER stress: study from a 3 × 3 factorial design

Background

Although exposure to individual metal does exhibit its toxicity, combined exposures provide a more effective representation of the toxic effects of different heavy metal exposures on public health as well as ecosystems. Furthermore, there are few studies on composite exposure to low concentrations of heavy metals, which is more consistent with real-life exposure. The purpose of this study was to explore the neurotoxicity induced by combined exposure to low concentrations of Lead (Pb) and cadmium (Cd) and the potential interaction of their mixture in vitro.

Methods

PC12 cells were incubation with the corresponding concentration of cadmium chloride and/or lead acetate. Viability of PC12 cells was measured by CCK8 assay after 12, 24 and 48h incubation. Next, We measured the ROS, mitochondrial membrane potential (MMP) and apoptosis produced by different treated cells using ROS assay kit, JC-1 MMP assay kit and annexin V-FITC/propidium iodide (PI) apoptosis assay kit, respectively. Expression of proteins related to PI3K/AKT and endoplasmic reticulum (ER) stress in PC12 cells were tested by western blotting. Our study was the first to analyze the interaction between Pb and Cd using a 3 × 3 factorial design approach to observe neurotoxicity.

Results

The results showed that the combined exposure of them was more cytotoxic than the single metal. The activation of PI3K/AKT signaling pathway and several parameters related to oxidative stress and ER stress were significantly altered in combined exposure to low concentrations of Pb and Cd compared with the Pb or Cd. Regarding apoptosis and ER stress, a synergistic interaction between Pb and Cd was evident. Moreover, evoked ER stress as a mechanism involved in the apoptosis of PC12 cells by the combined exposure to Pb and Cd.

Conclusion

The present study provides a theoretical basis used for the toxicological assessment of metal mixtures induced neurotoxicity of concern in terms of public health, and more effective control measures should be taken for the environmental pollution caused by various mixed heavy metals discharged from industry and agriculture.

Investigating the effect of myricetin against arsenic-induced cardiac toxicity in rats

Arsenic intoxication is a serious health hazard worldwide. Its toxicity is associated with several disorders and health problems in humans. Recent studies revealed that myricetin has various biological effects, including anti-oxidation. The aim of this study is to investigate the protective effect of myricetin against arsenic-induced cardiotoxicity in rats. Rats were randomized to one of the following groups: control, myricetin (2 mg/kg), arsenic (5 mg/kg), myricetin (1 mg/kg) + arsenic, and myricetin (2 mg/kg) + arsenic. Myricetin was given intraperitoneally 30 min before arsenic administration (5 mg/kg for 10 days). After treatments, the activity of lactate dehydrogenase (LDH) and the levels of aspartate aminotransferase (AST), creatine kinase myocardial band (CK-MB), lipid peroxidation (LPO), total antioxidant capacity (TAC), and total thiol molecules (TTM) were determined in serum samples and cardiac tissues. Also, histological changes in cardiac tissue were evaluated. Myricetin pretreatment inhibited arsenic-induced increase in LDH, AST, CK-MB, and LPO levels. Pretreatment with myricetin also enhanced the decreased TAC and TTM levels. In addition, myricetin improved histopathological alterations in arsenic-treated rats. In conclusion, the results of the present study demonstrated that treatment with myricetin prevented arsenic-induced cardiac toxicity at least in part by decreasing oxidative stress and restoring the antioxidant system.

Gallic and ascorbic acids supplementation alleviate cognitive deficits and neuropathological damage exerted by cadmium chloride in Wistar rats

Cadmium is a highly neurotoxic heavy metal that interferes with DNA repair mechanisms via generation of reactive oxygen species. The potentials of polyphenols and antioxidants as effective protective agents following heavy metal-induced neurotoxicity are emerging. We therefore explored the neuroprotective potentials of gallic and ascorbic acids in CdCl₂-induced neurotoxicity. Seventy-two Wistar rats were divided into six groups. Group A received distilled water, B: 3 mg/kg CdCl₂, C: 3 mg/kg CdCl₂ + 20 mg/kg gallic acid (GA), D: 3 mg/kg CdCl₂ + 10 mg/kg ascorbic acid (AA), E: 20 mg/kg GA and F: 10 mg/kg AA orally for 21 days. Depression, anxiety, locomotion, learning and memory were assessed using a battery of tests. Neuronal structure and myelin expression were assessed with histological staining and immunofluorescence. The Morris Water Maze test revealed significant increase in escape latency in CdCl₂ group relative to rats concurrently treated with GA or AA. Similarly, time spent in the target quadrant was reduced significantly in CdCl₂ group relative to other groups. Concomitant administration of gallic acid led to significant reduction in the durations of immobility and freezing that were elevated in CdCl₂ group during forced swim and open field tests respectively. Furthermore, GA and AA restored myelin integrity and neuronal loss observed in the CdCl₂ group. We conclude that gallic and ascorbic acids enhance learning and memory, decrease anxiety and depressive-like behavior in CdCl₂-induced neurotoxicity with accompanying myelin-protective ability.

Integrated Metabolomic and Transcriptomic Analysis Reveals Differential Flavonoid Accumulation and Its Underlying Mechanism in Fruits of Distinct Canarium album Cultivars

Canarium album fruit has great potential to be consumed as a raw material not only for food but also medicine. The diverse active metabolites composition and content of C. album fruits greatly affect their pharmacological effects. However, up to now, there has been no report on the global metabolome differences among fruits from distinct C. album cultivars. In our present study, by using non-targeted metabolomics techniques, we identified 87 DAMs (differentially accumulated metabolites) including 17 types of flavonoids from fruits of four different C. album cultivars. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis revealed that the flavone and flavonol biosynthesis- and flavonoid biosynthesis-related DAMs were major factors determining their metabolome differences. Comparative transcriptomic analysis revealed that 15 KEGG pathways were significantly enriched by genes of the identified 3655 DEGs (differentially expressed genes) among different C. album cultivars. Consistent with the metabolome data, flavonoid biosynthesis-related DEGs, including eight key structural genes (such as FLS, CCoAOMT, CHI, C4H, DFR, LAR, and C3′H, etc.) and several regulatory transcription factor (TF) genes (including 32 MYBs and 34 bHLHs, etc.), were found to be significantly enriched (p < 0.01). Our study indicated that the differential expression of flavonoid biosynthesis-related genes and accumulation of flavonoids played dominant roles in the various metabolome compositions of fruits from different C. album cultivars.

Myricetin (3,3',4',5,5',7-Hexahydroxyflavone) Prevents 5-Fluorouracil-Induced Cardiotoxicity

5-Fluorouracil (5-FU) is a strong anti-cancer drug used to manage numerous cancers. Cardiotoxicity, renal toxicity, and liver toxicity are some of the adverse effects which confine its clinical use to some extent. 5-FU-induced organ injuries are associated with redox imbalance, inflammation, and damage to heart functioning, particularly in the present study. Myricetin is an abundant flavonoid, commonly extracted from berries and herbs having anti-oxidative and anti-cancer activities. We planned the current work to explore the beneficial effects of myricetin against 5-FU-induced cardiac injury in Wistar rats through a biochemical and histological approach. Prophylactic myricetin treatment at two doses (25 and 50 mg/kg) was given to rats orally for 21 days against cardiac injury induced by a single injection of 5-FU (150 mg/kg b.wt.) given on the 20th day intraperitoneally. The 5-FU injection induced oxidative stress, inflammation, and extensive cardiac damage. Nevertheless, myricetin alleviated markers of inflammation, apoptosis, cardiac toxicity, oxidative stress, and upregulated anti-oxidative machinery. The histology of heart further supports our biochemical findings mitigated by the prophylactic treatment of myricetin. Henceforth, myricetin mitigates 5-FU-induced cardiac damage by modulating oxidative stress, inflammation, and cardiac-specific markers, as found in the present study.

Mechanosensitive Piezo1 Channel Evoked-Mechanical Signals in Atherosclerosis

Recently, more and more works have focused and used extensive resources on atherosclerosis research, which is one of the major causes of death globally. Alongside traditional risk factors, such as hyperlipidemia, smoking, hypertension, obesity, and diabetes, mechanical forces, including shear stress, pressure and stretches exerted on endothelial cells by flow, is proved to be crucial in atherosclerosis development. Studies have recognized the mechanosensitive Piezo1 channel as a special sensor and transducer of various mechanical forces into biochemical signals, and recent studies report its role in atherosclerosis through different mechanical forces in pressure, stretching and turbulent shear stress. Based on our expertise in this field and considering the recent advancement of atherosclerosis research, we will be focusing on the function of Piezo1 and its involvement in various cellular mechanisms and consequent involvement in the development of atherosclerosis in this review. Also, we will discuss various functions of Piezo1 involvement in atherosclerosis and come up with new mechanistic insight for future research. Based on the recent findings, we suggest Piezo1 as a valid candidate for novel therapeutic innovations, in which deep exploration and translating its findings into the clinic will be a new therapeutic strategy for cardiovascular diseases, particularly atherosclerosis.