Effect of Ginkgo biloba extract on the expressions of Cox-2 and GST-Pi in rats with hepatocellular carcinoma risk

New insight into the mechanisms of Ginkgo biloba leaves in the treatment of cancer

BACKGROUND

Ginkgo biloba leaves (GBLs), as an herbal dietary supplement and a traditional Chinese medicine, have been used in treating diseases for hundred years. Recently, increasing evidence reveals that the extracts and active ingredients of GBLs have anti-cancer (chemo-preventive) properties. However, the molecular mechanism of GBLs in anti-cancer has not been comprehensively summarized.

PURPOSE

To systematically summarize the literatures for identifying the molecular mechanism of GBLs in cellular, animal models and clinical trials of cancers, as well as for critically evaluating the current evidence of efficacy and safety of GBLs for cancers.

METHODS

Employing the search terms "Ginkgo biloba" and "cancer" till July 25, 2023, a comprehensive search was carried out in four electronic databases including Scopus, PubMed, Google Scholar and Web of Science. The articles not contained in the databases are performed by manual searches and all the literatures on anti-cancer research and mechanism of action of GBLs was extracted and summarized. The quality of methodology was assessed independently through PRISMA 2020.

RESULTS

Among 84 records found in the database, 28 were systematic reviews related to GBLs, while the remaining 56 records were related to the anticancer effects of GBLs, which include studies on the anticancer activities and mechanisms of extracts or its components in GBLs at cellular, animal, and clinical levels. During these studies, the top six cancer types associated with GBLs are lung cancer, hepatocellular carcinoma, gastric cancer, breast cancer, colorectal cancer, and cervical cancer. Further analysis reveals that GBLs primarily exert their anticancer effects by stimulating cancer cell apoptosis, inhibiting cell proliferation, invasion and migration of cancers, exhibiting anti-inflammatory and antioxidant properties, and modulating signaling pathways. Besides, the pharmacology, toxicology, and clinical research on the anti-tumor activity of GBLs have also been discussed.

CONCLUSIONS

This is the first paper to thoroughly investigate the pharmacology effect, toxicology, and the mechanisms of action of GBLs for anti-cancer properties. All the findings will reinforce the need to explore the new usage of GBLs in cancers and offer comprehensive reference data and recommendations for future research on this herbal medicine.

Contamination of Aflatoxins Induces Severe Hepatotoxicity Through Multiple Mechanisms

Aflatoxins (AFs) are commonly contaminating mycotoxins in foods and medicinal materials. Since they were first discovered to cause “turkey X” disease in the United Kingdom in the early 1960s, the extreme toxicity of AFs in the human liver received serious attention. The liver is the major target organ where AFs are metabolized and converted into extremely toxic forms to engender hepatotoxicity. AFs influence mitochondrial respiratory function and destroy normal mitochondrial structure. AFs initiate damage to mitochondria and subsequent oxidative stress. AFs block cellular survival pathways, such as autophagy that eliminates impaired cellular structures and the antioxidant system that copes with oxidative stress, which may underlie their high toxicities. AFs induce cell death via intrinsic and extrinsic apoptosis pathways and influence the cell cycle and growth via microribonucleic acids (miRNAs). Furthermore, AFs induce the hepatic local inflammatory microenvironment to exacerbate hepatotoxicity via upregulation of NF-κB signaling pathway and inflammasome assembly in the presence of Kupffer cells (liver innate immunocytes). This review addresses the mechanisms of AFs-induced hepatotoxicity from various aspects and provides background knowledge to better understand AFs-related hepatoxic diseases.

HBx combined with AFB1 triggers hepatic steatosis via COX-2-mediated necrosome formation and mitochondrial dynamics disorder

Hepatitis B virus (HBV) infection and aflatoxin B1 (AFB1) exposure have been recognized as independent risk factors for the occurrence and exacerbation of hepatic steatosis but their combined impacts and the potential mechanisms remain to be further elucidated. Here, we showed that exposure to AFB1 impaired mitochondrial dynamics and increased intracellular lipid droplets (LDs) in the liver of HBV-transgenic mice in vivo and the hepatitis B virus X protein (HBx)-expressing human hepatocytes both ex vivo and in vitro. HBx combined with AFB1 exposure also up-regulated receptor interaction protein 1 (RIP1), receptor interaction protein 3 (RIP3) and activated mixed lineage kinase domain like protein (MLKL), providing evidence of necrosome formation in the hepatocytes. The shift of the mitochondrial dynamics towards imbalance of fission and fusion was rescued when MLKL was inhibited in the HBx and AFB1 co-treated hepatocytes. Most importantly, based on siRNA or CRISPR/Cas9 system, we found that the combination of HBx and AFB1 exposure increased cyclooxygenase-2 (COX-2) to mediate up-regulation of RIP3 and dynamin-related protein 1 (Drp1), which in turn promoted location of RIP3-MLKL necrosome on mitochondria, subsequently exacerbated steatosis in hepatocytes. Taken together, these findings advance the understanding of mechanism associated with HBx and AFB1-induced hepatic necrosome formation, mitochondrial dysfunction and steatosis and make COX-2 a good candidate for treatment.