Association between oxidative stress, mitochondrial function of peripheral blood mononuclear cells and gastrointestinal cancers

Mitochondrial function and gastrointestinal diseases

Mitochondria are dynamic organelles that function in cellular energy metabolism, intracellular and extracellular signalling, cellular fate and stress responses. Mitochondria of the intestinal epithelium, the cellular interface between self and enteric microbiota, have emerged as crucial in intestinal health. Mitochondrial dysfunction occurs in gastrointestinal diseases, including inflammatory bowel diseases and colorectal cancer. In this Review, we provide an overview of the current understanding of intestinal epithelial cell mitochondrial metabolism, function and signalling to affect tissue homeostasis, including gut microbiota composition. We also discuss mitochondrial-targeted therapeutics for inflammatory bowel diseases and colorectal cancer and the evolving concept of mitochondrial impairment as a consequence versus initiator of the disease.

Molecular Mechanism of Natural Food Antioxidants to Regulate ROS in Treating Cancer: A Review

Cancer is the second-highest mortality rate disease worldwide, and it has been estimated that cancer will increase by up to 20 million cases yearly by 2030. There are various options of treatment for cancer, including surgery, radiotherapy, and chemotherapy. All of these options have damaging adverse effects that can reduce the patient's quality of life. Cancer itself arises from a series of mutations in normal cells that generate the ability to divide uncontrollably. This cell mutation can happen as a result of DNA damage induced by the high concentration of ROS in normal cells. High levels of reactive oxygen species (ROS) can cause oxidative stress, which can initiate cancer cell proliferation. On the other hand, the cytotoxic effect from elevated ROS levels can be utilized as anticancer therapy. Some bioactive compounds from natural foods such as fruit, vegetables, herbs, honey, and many more have been identified as a promising source of natural antioxidants that can prevent oxidative stress by regulating the level of ROS in the body. In this review, we have highlighted and discussed the benefits of various natural antioxidant compounds from natural foods that can regulate reactive oxygen species through various pathways.

Exploring the association between inflammatory biomarkers and gastric cancer development: A two-sample mendelian randomization analysis

This study aimed to elucidate the potential causative links between inflammatory biomarkers and gastric cancer risk via a two-sample Mendelian randomization approach. Leveraging genome-wide association study (GWAS) data, we conducted a two-sample Mendelian randomization analysis. Instrumental variable selection for inflammatory markers - namely, tissue factor, monocyte chemotactic protein-1, E-selectin, interleukin 6 receptor, and fatty acid-binding protein 4 - was informed by SNP data from the IEU database. Strongly associated SNPs served as instrumental variables. We applied a suite of statistical methods, including Inverse Variance Weighted (IVW), Weighted Median Estimator (WME), MR-Egger, and mode-based estimates, to compute the odds ratios (ORs) that articulate the impact of these markers on gastric cancer susceptibility. The IVW method revealed that the interleukin 6 receptor was inversely correlated with gastric cancer progression (OR = 0.86, 95% CI = 0.74-0.99, P = .03), whereas fatty acid-binding protein 4 was found to elevate the risk (OR = 1.21, 95% CI = 1.05-1.39, P = .03). Instrumental variables comprised 5, 4, 7, 2, and 3 SNPs respectively. Convergent findings from WME, MR-Egger, and mode-based analyses corroborated these associations. Sensitivity checks, including heterogeneity, horizontal pleiotropy assessments, and leave-one-out diagnostics, affirmed the robustness and reliability of our instruments across diverse gastric malignancy tissues without substantial bias. Our research suggests that the interleukin 6 receptor potentially mitigates, while fatty acid-binding protein 4 may contribute to the pathogenesis of gastric cancer (GC). Unraveling the intricate biological interplay between inflammation and oncogenesis offers valuable insights for preemptive strategies and therapeutic interventions in gastric malignancy management.

Alterations in mitochondria isolated from peripheral blood mononuclear cells and tumors of patients with epithelial ovarian cancers

Metabolic alterations play an essential role in ovarian carcinogenesis. The flexibility of mitochondrial functions facilitates cellular adaptation to the tough environment associated with carcinogenesis. An understanding of the differences in mitochondrial functions in normal ovaries and cancers could provide a basis for further exploration of future mitochondria-based screening, diagnosis, prognostic prediction, and targeted therapy for epithelial ovarian cancers. The main objective of this study was to assess mitochondrial function profiles measured from PBMCs and ovarian tissues of epithelial ovarian cancers in comparison with normal ovaries. A total of 36 patients were recruited for the study, all of whom underwent primary surgical treatment for malignant epithelial ovarian neoplasm. Of these, 20 patients were in the early stage and 16 patients were in the advanced stage. Additionally, 21 patients who had pelvic surgery for benign gynecologic conditions, with normal ovaries incidentally removed, were recruited as controls. At the time of surgery, a blood sample was collected from each participant for PBMC isolation, and ovarian tissue was retained for molecular studies. These studies included the examination of oxidative stress, mitochondrial mass, mitochondrial respiration, mitochondrial reactive oxygen species (ROS), mitochondrial membrane potential (MMP) changes, and mitochondrial swelling. Clinical and histopathological data were also collected and compared between different stages of epithelial ovarian cancers: early-stage (group 1), advanced-stage (group 2), and normal ovaries (group 3). The levels of cellular oxidative stress, mitochondrial mass, and mitochondrial biogenesis in the peripheral blood mononuclear cells (PBMCs) of participants with ovarian cancer were significantly lower than those of the control group. However, the mitochondrial respiratory parameters measured from the PBMCs were similar across all three groups. Furthermore, mitochondrial membrane depolarization and mitochondrial swelling were observed in ovarian tissues of both early-stage and advanced-stage cancer groups. We demonstrated the dynamic nature of mitochondrial ROS production, biogenesis, and respiratory function in response to epithelial ovarian carcinogenesis. The flexibility of mitochondrial functions under diverse conditions may make it a challenging therapeutic target for ovarian cancer.

Oxido-Reduction Potential as a Method to Determine Oxidative Stress in Semen Samples

There are different estimates for the incidence of infertility. Its occurrence may vary from area to area, but on average, it affects 15% of couples and 10-12% of men worldwide. Many aspects of infertility can be linked to reactive oxygen species (ROS) and the process of oxidative stress (OS). The association between poor semen quality and OS is well known. Unfortunately, there is no accepted protocol for the diagnosis and treatment of OS in andrology. Oxido-reduction potential (ORP) measurement is a new method for determining the ratio between oxidant and antioxidant molecules. Currently, ORP measurement is one of the fastest and most user-friendly methods of andrological OS determination and our goals were to confirm published correlations between ORP values and sperm parameters, examine how sperm concentration influences these results, and investigate whether intracellular ROS formations are also manifested in the ORP values or not after artificial ROS induction. Intracellular ROS formations were induced by menadione (superoxide anion inducer), hydrogen peroxide, and tert-butyl hydroperoxide (lipid peroxidation inducer) treatments; sperm parameters like motility and viability were determined with an SCA Scope system, and ORP changes were recorded by the Mioxsys system. Significant correlations were noticed among the ORP, spermatozoa concentration, motility, progressive motility, and viability. Nevertheless, only the ORP value after normalization with the sperm count correlated with these parameters. Due to normalization, very low and very high sperm concentrations can give misleading results. The means of the non-normalized ORP values were almost the same. All of the applied treatments resulted in decreases in the viability, motility, and progressive motility, and interestingly, altered ORP levels were detected. In addition, it was determined that seminal plasma had a significant protective effect on spermatozoa. The elimination of seminal plasma caused higher sensitivity of spermatozoa against used OS inducers, and higher ORP levels and decreased viabilities and motilities were measured. The ORP level could be a good indicator of male OS; however, in cases of low and high sperm counts, its result can be misleading. Overall, the conclusion can be drawn that ORP determination is a suitable method for detecting intracellular ROS accumulation, but it has limitations that still need to be clarified.