An Oleocanthal-Enriched EVO Oil Extract Induces the ROS Production in Gastric Cancer Cells and Potentiates the Effect of Chemotherapy

GDF15 induces chemoresistance to oxaliplatin by forming a reciprocal feedback loop with Nrf2 to maintain redox homeostasis in colorectal cancer

PURPOSE

Growth differentiating Factor 15 (GDF15) is linked to several cancers, but its effect on chemoresistance in colorectal cancer (CRC) remains unclear. Here, we investigated the role of GDF15 in the chemotherapeutic response of CRC patients to oxaliplatin (L-OHP).

METHODS

GDF15 levels in serum and tumour tissues were detected in CRC patients have received L-OHP-based neoadjuvant chemotherapy. The effects of GDF15 neutralization or GDF15 knockdown on cell proliferation, apoptosis and intracellular reactive oxygen species (ROS) levels were analysed in vitro and in vivo. Co-immunoprecipitation (Co-IP), Chromatin Immunoprecipitation (ChIP) and luciferase reporter assays were used to explore the interaction between GDF15 and Nrf2.

RESULTS

In this study, we found that GDF15 alleviates oxidative stress to induce chemoresistance of L-OHP in CRC. Mechanically, GDF15 posttranscriptionally regulates protein stability of Nrf2 through the canonical PI3K/AKT/GSK3β signaling pathway, and in turn, Nrf2 acts as a transcription factor to regulate GDF15 expression to form a positive feedback loop, resulting in the maintenance of redox homeostasis balance in CRC. Furthermore, a positive correlation between GDF15 and Nrf2 was observed in clinical CRC samples, and simultaneous overexpression of both GDF15 and Nrf2 was associated with poor prognosis in CRC patients treated with L-OHP. Simultaneous inhibition of both GDF15 and Nrf2 significantly increases the response to L-OHP in an L-OHP-resistant colorectal cancer cells-derived mouse xenograft model.

CONCLUSION

This study identified a novel GDF15-Nrf2 positive feedback loop that drives L-OHP resistance and suggested that the GDF15-Nrf2 axis is a potential therapeutic target for the treatment of L-OHP-resistant CRC.

Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches

Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L.

Wild and cultivated olive trees: Nutraceutical insights of extra virgin olive oils in cardiovascular and ocular diseases

Extra virgin olive oil (EVOO) from Olea europaea (cultivated olive tree) and the oil obtained from the wild olive variety or acebuche (ACE oil from Olea oleaster) contain an extraordinary number of bioactive molecules. These include oleic acid, sterols, tocopherols, triterpene compounds, and polyphenols. Both oils are known for their healthy properties and are considered to be a nutraceutical tool against cardiovascular diseases, including arterial hypertension, preeclampsia, and ocular diseases such as glaucoma or diabetic retinopathy. The benefits of EVOO and ACE oil stem from their anti-inflammatory, antioxidant, and anti-cancer properties. They also have potential as prebiotic compounds. In this update, we synthesise and illustrate the various characteristics and beneficial effects of olive oils from different varieties of olive trees, with special emphasis on Olea oleaster, also known as Olea europaea, L. var. sylvestris.

Oleocanthal, an Antioxidant Phenolic Compound in Extra Virgin Olive Oil (EVOO): A Comprehensive Systematic Review of Its Potential in Inflammation and Cancer

BACKGROUND

The Mediterranean diet is linked to various health benefits, especially the consumption of olive oil as a key component. Multiple studies highlight its advantages, particularly due to its fatty acid composition and additional components like phenolic compounds. A significant antioxidant compound, oleocanthal, known for its antioxidant properties, has gained attention in the pharmaceutical industry for its anti-inflammatory and antiproliferative effects. It shows promise in addressing cardiovascular diseases, metabolic syndrome, and neuroprotection. This systematic review aims to evaluate the existing literature on oleocanthal, examining its role in biological processes and potential impact on conditions like inflammation and cancer.

METHODS

We performed several searches in PubMed (MEDLINE), Web of Science (WOS), and Cochrane based on the terms "Oleocanthal", "Cancer", and "Inflammation". The inclusion criteria were as follows: studies whose main topics were oleocanthal and cancer or inflammation. On the other hand, the exclusion criteria were studies that were not focused on oleocanthal, reviews, or editorial material. Given that these findings are explanatory rather than derived from clinical trials, we refrained from employing methods to assess potential bias. This systematic review did not receive any external funding.

RESULTS

We found 174 records from these searches, where we discarded reviews and editorial material, duplicated articles, and 1 retracted article. Finally, we had 53 reports assessed for eligibility that were included in this review.

DISCUSSION

OC exhibits promising therapeutic potential against both inflammation and cancer. We addressed its ability to target inflammatory genes and pathways, offering potential treatments for conditions like rheumatic diseases by regulating pathways such as NF-kB and MAPK. Additionally, OC's anticancer properties, particularly its notable inhibition of c-Met signaling across various cancers, highlight its efficacy, showcasing promise as a potential treatment.

The CAIX inhibitor SLC-0111 exerts anti-cancer activity on gastric cancer cell lines and resensitizes resistant cells to 5-Fluorouracil, taxane-derived, and platinum-based drugs

Gastric cancer (GC) is the fifth most frequent malignancy and the fourth leading cause of worldwide cancer-related death. Despite the usage of multimodal perioperative chemotherapy (pCT), GC progressively gains chemoresistance, thereby, the identification of suitable targets to overcome drug resistance is fundamental. Amongst the potential biomarkers, carbonic anhydrase IX (CAIX) - associated with a poor prognosis of several solid cancers - has gained the most attention. In a cohort of GC patients who received perioperative FLOT (i.e., Leucovorin, 5-Fluouracil, Docetaxel, and Oxaliplatin) or FOLFOX (i.e., Leucovorin, 5-Fluouracil, and Oxaliplatin), non-responder patients showed an increased expression of tumor CAIX compared to responder group. Moreover, GC cell lines induced to be resistant to 5-Fluouracil, Paclitaxel, Cisplatin, or the combination of 5-Fluorouracil, Oxaliplatin, and Docetaxel, overexpressed CAIX compared to the control. Accordingly, CAIX-high-expressing GC cells showed increased therapy resistance compared to low-expressing cells. Notably, SLC0111 significantly improved the therapy response of both wild-type and resistant GC cells. Overall, these data suggest a correlation between CAIX and GC drug resistance highlighting the potential of SLC-0111 in re-sensitizing GC cells to pCT.

AGS Gastric Cells: Antioxidant Activity and Metabolic Effects of Phenolic Extracts from Different Monocultivar Virgin Olive Oils

The effects of the phenolic compounds of extra virgin olive oil (EVOO) on AGS cells have never been studied so far, which is the aim of this study. The profiles of the main phenolic components in EVOOs, mainly secoiridoid compounds derived from the transformation of oleuropein during the olive milling process, were evaluated and compared. Oils of different origins were evaluated aiming at verifying whether chemical differences in the phenolic composition of the dry extracts played a role in the metabolism and in maintaining the cellular redox state of AGS cells. The following key enzymes of some metabolic pathways were studied: lactate dehydrogenase, enolase, pyruvate kinase, glucose 6-phosphate dehydrogenase, citrate synthase, 3-Hydroxyacyl-CoA dehydrogenase and hexokinase. As confirmed through PCA analysis, pretreatments with the dry extracts of EVOOs at different concentrations appeared to be able to counteract the enzymatic activity alterations due to oxidative stress induced by H₂O₂ 1 mM and 2 mM. The studied phytocomplexes showed the ability to protect AGS cells from oxidative damage and the secoiridoid derivatives from both oleuropein and ligstroside contributed to the observed effects. The results suggested that EVOOs with medium to high concentrations of phenols can exert this protection.

Gastric Cancer Vascularization and the Contribution of Reactive Oxygen Species

Blood vessels are the most important way for cancer cells to survive and diffuse in the body, metastasizing distant organs. During the process of tumor expansion, the neoplastic mass progressively induces modifications in the microenvironment due to its uncontrolled growth, generating a hypoxic and low pH milieu with high fluid pressure and low nutrients concentration. In such a particular condition, reactive oxygen species play a fundamental role, enhancing tumor proliferation and migration, inducing a glycolytic phenotype and promoting angiogenesis. Indeed, to reach new sources of oxygen and metabolites, highly aggressive cancer cells might produce a new abnormal network of vessels independently from endothelial cells, a process called vasculogenic mimicry. Even though many molecular markers and mechanisms, especially in gastric cancer, are still unclear, the formation of such intricate, leaky and abnormal vessel networks is closely associated with patients' poor prognosis, and therefore finding new pharmaceutical solutions to be applied along with canonical chemotherapies in order to control and normalize the formation of such networks is urgent.