Crocin reverses 1-methyl-3-nitroso-1-nitroguanidine (MNNG)-induced malignant transformation in GES-1 cells through the Nrf2/Hippo signaling pathway

An Overview of the Spices Used for the Prevention and Potential Treatment of Gastric Cancer

Gastric cancer (GC) ranks third in terms of cancer-related deaths and is the fifth most commonly diagnosed type of cancer. Its risk factors include Helicobacter pylori infection, Epstein-Barr virus infection, the consumption of broiled and charbroiled animal meats, salt-preserved and smoke-enhanced foods, alcohol drinking, tobacco smoking, exposure to ionizing radiation, and positive family history. The limited effectiveness of conventional therapies and the widespread risk factors of GC encourage the search for new methods of treatment and prevention. In the quest for cheap and commonly available medications, numerous studies focus on herbal medicine, traditional brews, and spices. In this review, we outline the potential use of spices, including turmeric, ginger, garlic, black cumin, chili pepper, saffron, black pepper, rosemary, galangal, coriander, wasabi, cinnamon, oregano, cardamom, fenugreek, caraway, clove, dill, thyme, Piper sarmentosum, basil, as well as the compounds they contain, in the prevention and treatment of GC. We present the potential molecular mechanisms responsible for the effectivity of a given seasoning substance and their impact on GC cells. We discuss their potential effects on proliferation, apoptosis, and migration. For most of the spices discussed, we also outline the unavailability and side effects of their use.

Long-term MNNG exposure promotes gastric carcinogenesis by activating METTL3/m6A/miR1184 axis-mediated epithelial-mesenchymal transition

As the representative item of environmental chemical carcinogen, MNNG was closely associated with the onset of Gastric cancer (GC), while the underlying mechanisms remain largely unknown. Here, we comprehensively analyzed the potential clinical significance of METTL3 in multiple GC patient cohorts. Additionally, we demonstrated that long-term exposure to MNNG elevated METTL3 and EMT marker expression by in vitro and in vivo models. Furthermore, the depletion of METTL3 impacted the proliferation, migration, invasion, and tumorigenesis of MNNG malignant transformation cells and GC cells. By me-RIP sequencing, we identified a panel of vital miRNAs potentially regulated by METTL3 that aberrantly expressed in MNNG-induced GC cells. Mechanistically, we showed that METTL3 meditated miR-1184/TRPM2 axis by regulating the process of miRNA-118. Our results provide novel insights into critical epigenetic molecular events vital to MNNG-induced gastric carcinogenesis. These findings suggest the potential therapeutic targets of METTL3 for GC treatment.

Advances on the anti-tumor mechanisms of the carotenoid Crocin

Saffron is located in the upper part of the crocus stigma of iridaceae, which has a long history of medicinal use. Crocin (molecular formula C44H64O24) is a natural floral glycoside ester compound extracted from saffron, which is a type carotenoid. Modern pharmacological studies have shown that crocin has multiple therapeutic effects including anti-inflammatory, anti-oxidant, anti-hyperlipidemic and anti-stone effects. In recent years, crocin has been widely noticed due to its considerable anti-tumor effects manifested by the induction of tumor cell apoptosis, inhibition of tumor cell proliferation, inhibition of tumor cell invasion and metastasis, enhancement of chemotherapy sensitivity and improvement of immune status. The anti-tumor effects have been shown in various malignant tumors such as gastric cancer, liver cancer, cervical cancer, breast cancer and colorectal cancer. In this review, we compiled recent studies on the anti-tumor effects of crocin and summarized its anti-tumor mechanism for developing ideas of treating malignancies and exploring anti-tumor drugs.

The effect of phytochemicals in N-methyl-N-nitro-N-nitroguanidine promoting the occurrence and development of gastric cancer

Gastric cancer is a common malignant tumor of the digestive tract, with a low early diagnosis rate. N-methyl-N-nitro-N-nitroguanidine (MNNG) is one of the main risk factors for gastric cancer. Phytochemicals are healthy active substances derived from vegetables, fruits, nuts, tea, herbal medicines and other plants. Taking phytochemicals is a very promising strategy for the prevention and treatment of gastric cancer. Many studies have proved that phytochemicals have protective effects on MNNG induced gastric cancer via inhibiting cell proliferation, enhancing immunity, suppressing cell invasion and migration, inducing apoptosis and autophagy, blocking angiogenesis, inhibiting Helicobacter pylori infection as well as regulating metabolism and microbiota. The intervention and therapeutic effects of phytochemicals in MNNG induced gastric cancer have attracted more and more attention. In order to better study and explore the role, advantages and challenges of phytochemicals in MNNG induced gastric cancer, we summarized the intervention and therapeutic effects of phytochemicals in MNNG induced gastric cancer. This review may help to further promote the research and clinical application of phytochemicals in MNNG induced gastric cancer, and provide some new insights.

Nrf2 Downregulation Contributes to Epithelial-to-Mesenchymal Transition in Helicobacter pylori-Infected Cells

Simple Summary

Gastric cancer is mainly linked to Helicobacter pylori infection. It is therefore important to decipher the mechanisms involved in H. pylori-induced gastric carcinogenesis, and especially the early events. We have previously demonstrated that the infection leads to an epithelial-to-mesenchymal transition (EMT) favoring gastric carcinogenesis. H. pylori infection is also associated with high levels of oxidative stress. In this work, we aimed at investigating the modulation of Nrf2, a major regulator of cellular antioxidant response to oxidative stress, upon infection with H. pylori and to decipher its implication in EMT. We demonstrated that H. pylori-induced Nrf2 downregulation may participate in gastric cells’ EMT, one crucial tumorigenic event in gastric cancer. These results could pave the way for new therapeutic strategies using Nrf2 modulators to reduce gastric carcinogenesis associated with H. pylori infection.

Abstract

Background: Gastric cancer, the fifth most common cancer worldwide, is mainly linked to Helicobacter pylori infection. H. pylori induces chronic inflammation of the gastric mucosa associated with high oxidative stress. Our study aimed at assessing the implication of Nrf2, a major regulator of cellular redox homeostasis, in H. pylori-induced gastric carcinogenesis. Methods: Using three different gastric epithelial cell lines, a non-cancerous (HFE-145) and two different subtypes of gastric cancer (AGS and MKN74), we analyzed the modulation of Nrf2 expression over time. After invalidation of Nrf2 by CRISPR-cas9, we assessed its role in H. pylori-induced epithelial-to-mesenchymal transition (EMT). Finally, we evaluated the expression of Nrf2 and ZEB1, a central EMT transcription factor, in human gastric tissues. Results: We first demonstrated that the Nrf2 signaling pathway is differentially regulated depending on the infection stage. Rapidly and transiently activated, Nrf2 was downregulated 24 h post-infection in a VacA-dependent manner. We then demonstrated that Nrf2 invalidation leads to increased EMT, which is even exacerbated after H. pylori infection. Finally, Nrf2 expression tended to decrease in human patients’ gastric mucosa infected with H. pylori. Conclusions: Our work supports the hypothesis that Nrf2 downregulation upon H. pylori infection participates in EMT, one of the most important events in gastric carcinogenesis.

Crocin molecular signaling pathways at a glance: A comprehensive review

Crocin is a hydrophilic carotenoid that is synthesized in the flowers of the Crocus genus. Numerous in vitro and in vivo research projects have been published about the biological and pharmacological properties and toxicity of crocin. Crocin acts as a memory enhancer, anxiolytic, aphrodisiac, antidepressant, neuroprotective, and so on. Here, we introduce an updated and comprehensive review of crocin molecular mechanisms based on previously examined and mentioned in the literature. Different studies confirmed the significant effect of crocin to control pathological conditions, including oxidative stress, inflammation, metabolic disorders, neurodegenerative disorders, and cancer. The neuroprotective effect of crocin could be related to the activation of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT)/mammalian target of rapamycin (mTOR), Notch, and cyclic-AMP response element-binding protein signaling pathways. The crocin also protects the cardiovascular system through the inhibitory effect on toll-like receptors. The regulatory effect of crocin on PI3K/AKT/mTOR, AMP-activated protein kinase, mitogen-activated protein kinases (MAPK), and peroxisome proliferator-activated receptor pathways can play an effective role in the treatment of metabolic disorders. The crocin has anticancer activity through the PI3K/AKT/mTOR, MAPK, vascular endothelial growth factor, Wnt/β-catenin, and Janus kinases-signal transducer and activator of transcription suppression. Also, the nuclear factor-erythroid factor 2-related factor 2 and p53 signaling pathway activation may be effective in the anticancer effect of crocin. Finally, among signaling pathways regulated by crocin, the most important ones seem to be those related to the regulatory effect on the PI3K/AKT/mTOR pathway.

Interaction of saffron and its constituents with Nrf2 signaling pathway: A review

Saffron (Crocus sativus) is a natural compound and its constituents such as crocin, crocetin, and safranal have many pharmacological properties such as anti-oxidant, anti-inflammatory, antitumor, antigenotoxic, anti-depressant, hepatoprotective, cardioprotective, and neuroprotective. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays an important role against inflammation, oxidative stress, and carcinogenesis. In the regulation of the Nrf2 signaling pathway, kelch-like ECH-associated protein 1 (keap1) is the most studied pathway. In this review, we gathered various studies and describe the pharmacological effects of saffron and its constituents with their related mechanisms of action, particularly the Nrf2 signaling pathway. In this review, we used search engines or electronic databases including Scopus, Web of Science, and Pubmed, without time limitation. The search keywords contained saffron, "Crocus sativus", crocetin, crocin, safranal, picrocrocin, "nuclear factor erythroid 2-related factor 2", and Nrf2. Saffron and its constituents could have protective properties through various mechanisms particularly the Nrf2/HO-1/Keap1 signaling pathway in different tissues such as the liver, heart, brain, pancreas, lung, joints, colon, etc. The vast majority of studies discussed in this review indicate that saffron and its constituents could induce the Nrf2 signaling pathway leading to its anti-oxidant and therapeutic effects.

Crocin Alleviates Intracerebral Hemorrhage-Induced Neuronal Ferroptosis by Facilitating Nrf2 Nuclear Translocation

Intracerebral hemorrhage (ICH) is the deadliest type of stroke. Oxidative stress was considered to play an important role in ICH-induced secondary injury. Crocin, the main compound isolated from Crocus sativus L., possesses a potential anti-oxidative function in many types of diseases including ICH. In the current study, the protective role of crocin in ICH-induced brain injury was investigated in the ICH model. The ICH-induced brain edema and neurological deficits were analyzed by brain edema measurement and neurological testing. The superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activity and the content of malondialdehyde (MDA) were assessed by a total superoxide dismutase assay kit. The expressions of ferroptosis-related genes were verified by quantitative real-time PCR (qPCR) and western blotting. The ICH-induced brain edema and neurological deficits were significantly decreased after treatment with crocin. Moreover, the SOD and GSH-px activities were obviously increased in the ICH with crocin-treated group compared with the ICH group, while the content of MDA was markedly decreased after treatment with crocin. Crocin inhibited ferroptosis of neuron cells, as evidenced by increased Fe²⁺ concentration and the expression of GPX4, FTH1, and SLC7A11. Mechanistically, crocin treatment increased the expression and nuclear translocation of Nrf2. Our data suggest that crocin alleviates intracerebral hemorrhage-induced neuronal ferroptosis by facilitating Nrf2 nuclear translocation.

Metabolic Reprogramming in Gastric Cancer: Trojan Horse Effect

Worldwide, gastric cancer (GC) represents the fifth most common cancer for incidence and the third leading cause of death in developed countries. Despite the development of combination chemotherapies, the survival rates of GC patients remain unsatisfactory. The reprogramming of energy metabolism is a hallmark of cancer, especially increased dependence on aerobic glycolysis. In the present review, we summarized current evidence on how metabolic reprogramming in GC targets the tumor microenvironment, modulates metabolic networks and overcomes drug resistance. Preclinical and clinical studies on the combination of metabolic reprogramming targeted agents and conventional chemotherapeutics or molecularly targeted treatments [including vascular endothelial growth factor receptor (VEGFR) and HER2] and the value of biomarkers are examined. This deeper understanding of the molecular mechanisms underlying successful pharmacological combinations is crucial in finding the best-personalized treatment regimens for cancer patients.

Erianin, the main active ingredient of Dendrobium chrysotoxum Lindl, inhibits precancerous lesions of gastric cancer (PLGC) through suppression of the HRAS-PI3K-AKT signaling pathway as revealed by network pharmacology and in vitro experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium chrysotoxum Lindl, a well-known traditional Chinese medicinal herb used in the treatment of gastric disease, is distinguished as the first of the "nine immortal grasses". Dendrobium chrysotoxum Lindl and the traditional Chinese medicine prescriptions containing Dendrobium chrysotoxum Lindl are often prescribed clinically to treat chronic gastritis and precancerous lesions of gastric cancer (PLGC), showing favorable clinical effects and medicinal value in the prevention of gastric cancer. However, the effective ingredients and pharmacological mechanisms through which Dendrobium chrysotoxum Lindl prevents and treats PLGC have not been adequately identified or interpreted.

AIM OF THE STUDY

The present study aimed to evaluate the effective ingredients and pharmacological mechanisms of Dendrobium chrysotoxum Lindl in the prevention and treatment of PLGC using network pharmacology. In addition, in vitro verification was performed to evaluate the mechanism of action of Erianin, the main active ingredient in Dendrobium chrysotoxum Lindl, providing experimental evidence for the clinical use of Dendrobium chrysotoxum Lindl in the treatment of PLGC.

MATERIALS AND METHODS

Using network pharmacology methods, the main ingredients in Dendrobium chrysotoxum Lindl were screened from the ETCM, BATMAN-TCM, and TCMID databases, and their potential targets were predicted using the Swiss Target Prediction platform. The targets related to PLGC were retrieved through the GeneCard database, and the targets common to the main ingredients of Dendrobium chrysotoxum Lindl and PLGC were analyzed. The protein-protein interaction (PPI) network was obtained via the STRING database and analyzed visually using Cytoscape 3.7.2. The underlying mechanisms of the common targets identified through gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were analyzed using DAVID online. The "component-target-pathway" networks of Dendrobium chrysotoxum Lindl and Erianin were visually constructed by Cytoscape 3.7.2. The biological activity evaluation of Erianin's effect on PLGC was carried out using MC cell lines, the PLGC cell model established using MNNG to induce damage in normal gastric mucosal epithelial cell (GES-1). After the intervention of different concentrations of Erianin, MC cell viability was explored using the MTT assays, cell migration was determined by wound healing assays, the cell cycle and apoptosis were analyzed using flow cytometry, and the expression levels of related proteins and their phosphorylation in the HRAS-PI3K-AKT signaling pathway were detected by Western blot.

RESULTS

The "component-target-pathway" network constructed in this study showed 37 active ingredients from Dendrobium chrysotoxum Lindl and 142 overlapping targets related to both Dendrobium chrysotoxum Lindl and PLGC. The targets were associated with a variety of cancer-related signaling pathways, including Pathways in cancer, PI3K-Akt signaling pathway, Rap1 signaling pathway, Focal adhesion, Ras signaling pathway, and MAPK signaling pathway. Notably, the network showed that Erianin, the primary active ingredient from Dendrobium chrysotoxum Lindl and the component associated with the most targets, could regulate Pathways in cancer, PI3K-AKT signaling pathway, Focal adhesion, Rap1 signaling pathway, cell cycle, and RAS signaling pathway in the treatment of PLGC. Verification through in vitro experiments found that Erianin can significantly inhibit MC cell viability, inhibit cell migration, block the cell cycle in the G2/M phase, and induce cell apoptosis in a dose-dependent manner. The results of the Western blot experiment further showed that Erianin can significantly decrease the protein expression levels of HRAS, AKT, p-AKT, MDM2, Cyclin D1, and p-Gsk3β, and increase the protein expression level of p21, which suggests that Erianin can treat PLGC by regulating the HRAS-PI3K-AKT signaling pathway.

CONCLUSION

This study explained the positive characteristics of multi-component, multi-target, and multi-approach intervention with Dendrobium chrysotoxum Lindl in the treatment of PLGC. Our results suggest that Erianin may be a promising candidate in the development of prevention and treatment methods for PLGC. This study provided experimental evidence for the clinical use of Dendrobium chrysotoxum Lindl to treat PLGC and prevent gastric cancer.