Gender differences in the antioxidant response of oral administration of hydroxytyrosol and oleuropein against N-ethyl-N-nitrosourea (ENU)-induced glioma

Gender Differences in Oxidative Stress in Relation to Cancer Susceptibility and Survival

Genetic, developmental, biochemical, and environmental variables interact intricately to produce sex differences. The significance of sex differences in cancer susceptibility is being clarified by numerous studies. Epidemiological research and cancer registries have revealed over the past few years that there are definite sex variations in cancer incidence, progression, and survival. However, oxidative stress and mitochondrial dysfunction also have a significant impact on the response to treatment of neoplastic diseases. Young women may be more protected from cancer than men because most of the proteins implicated in the regulation of redox state and mitochondrial function are under the control of sexual hormones. In this review, we describe how sexual hormones control the activity of antioxidant enzymes and mitochondria, as well as how they affect several neoplastic diseases. The molecular pathways that underlie the gender-related discrepancies in cancer that have been identified may be better understood, which may lead to more effective precision medicine and vital information on treatment options for both males and females with neoplastic illnesses.

Prophylactic role of olive fruit extract against cigarette smoke-induced oxidative stress in Sprague-Dawley rats

Cigarette smoke exposure increases the production of free radicals leading to initiation of several pathological conditions by triggering the oxidative stress and inflammatory cascade. Olive fruit owing to its unique phytochemical composition possesses antioxidant, immune modulatory, and anti-inflammatory potential. Considering the compositional alterations in olive fruits during ripening, the current experimental trail was designed to investigate the prophylactic role of green and black olives against the oxidative stress induced by cigarette smoke exposure in rats. Purposely, rats were divided into five different groups: NC (negative control; normal diet), PC [positive control; normal diet + smoke exposure (SE)], drug (normal diet + SE + citalopram), GO (normal diet + SE + green olive extract), and BO (normal diet + SE + black olive extract). Rats of all groups were exposed to cigarette smoke except "NC" and were sacrificed for collection of blood and organs after 28 days of experimental trial. The percent reduction in total oxidative stress by citalopram and green and black olive extracts in serum was 29.72, 58.69, and 57.97%, respectively, while the total antioxidant capacity increased by 30.78, 53.94, and 43.98%, accordingly in comparison to PC. Moreover, malondialdehyde (MDA) was reduced by 29.63, 42.59, and 45.70% in drug, GO, and BO groups, respectively. Likewise, green and black olive extracts reduced the leakage of hepatic enzymes in sera, alkaline phosphatase (ALP) by 23.44 and 25.80% and 35.62 and 37.61%, alanine transaminase (ALT) by 42.68 and 24.39% and 51.04 and 35.41%, and aspartate transaminase (AST) by 31.51 and 16.07% and 40.50 and 27.09% from PC and drug group, respectively. Additionally, olive extracts also maintained the antioxidant pool, i.e., superoxide dismutase, catalase, and glutathione in serum. Furthermore, histological examination revealed that olive extracts prevented the cigarette smoke-induced necrosis, pyknotic alterations, and congestion in the lung, hepatic, and renal parenchyma. Besides, gene expression analysis revealed that olive extracts and citalopram decreased the brain and lung damage caused by stress-induced upregulation of NRF-2 and MAPK signaling pathways. Hence, it can be concluded that olives (both green and black) can act as promising antioxidant in alleviating the cigarette smoke-induced oxidative stress.

Hydroxytyrosol Dimers from Medicinal Insect Blaps Rynchopetera and the in Vitro Cytotoxic Activity

The edible Blaps rynchopetera Fairmaire is widely used for its various medicinal effects. From its ethyl acetate fraction, three new hydroxytyrosol dimers, rynchopeterine H (1), rynchopeterine I (2) and trans-2-(3,4-dihydroxy-phenyl)-3-hydroxy-7-(2-hydroxyethyl)-1,4-benzdioxane (3), together with four known similar dimers were obtained by chromatography of silica gel and Sephadex LH-20. Their structures were identified by HRESIMS, 1D and 2D NMR spectra analysis. Compounds 1-4 were obtained as a mixture, and cytotoxicity screening for HepG2, Caco-2, U251, AGS, B16 and Bel-7402 cell lines showed that the mixture of compounds 1-4 exhibited significantly selective cytotoxicity and good inhibitory activity on the proliferation of mouse melanoma cells (B16) with an IC50 value of 27.37 μg·mL−1.

Redox modulation by plant polyphenols targeting vitagenes for chemoprevention and therapy: Relevance to novel anti-cancer interventions and mini-brain organoid technology

The scientific community, recently, has focused notable attention on the chemopreventive and therapeutic effects of dietary polyphenols for human health. Emerging evidence demonstrates that polyphenols, flavonoids and vitamins counteract and neutralize genetic and environmental stressors, particularly oxidative stress and inflammatory process closely connected to cancer initiation, promotion and progression. Interestingly, polyphenols can exert antioxidant or pro-oxidant cytotoxic effects depending on their endogenous concentration. Notably, polyphenols at high dose act as pro-oxidants in a wide type of cancer cells by inhibiting Nrf2 pathway and the expression of antioxidant vitagenes, such as NAD(P)H-quinone oxidoreductase (NQO1), glutathione transferase (GT), GPx, heme oxygenase-1 (HO-1), sirtuin-1 (Sirt1) and thioredoxin (Trx) system which play an essential role in the metabolism of reactive oxygen species (ROS), detoxification of xenobiotics and inhibition of cancer progression, by inducing apoptosis and cell cycle arrest according to the hormesis approach. Importantly, mutagenesis of Nrf2 pathway can exacerbate its "dark side" role, representing a crucial event in the initiation stage of carcinogenesis. Herein, we review the hormetic effects of polyphenols and nanoincapsulated-polyphenols in chemoprevention and treatment of brain tumors via activation or inhibition of Nrf2/vitagenes to suppress carcinogenesis in the early stages, and thus inhibit its progression. Lastly, we discuss innovative preclinical approaches through mini-brain tumor organoids to study human carcinogenesis, from basic cancer research to clinical practice, as promising tools to recapitulate the arrangement of structural neuronal tissues and biological functions of the human brain, as well as test drug toxicity and drive personalized and precision medicine in brain cancer.

An updated review on the potential antineoplastic actions of oleuropein

Oleuropein is an ester of elenolic acid and hydroxytyrosol (3, 4-dihydroxyphenylethanol). It is a phenolic compound and the most luxuriant in olives. The detailed information related to the anticancer effects of oleuropein was collected from the internet database PubMed/Medline, ResearchGate, Web of Science, Wiley Online Library, and Cnki using appropriate keywords until the end of October 2021. Oleuropein has been shown to have antioxidant, anticancer, antiinflammatory, cardioprotective, neuroprotective, and hepatoprotective effects. Previous studies also revealed that oleuropein could effectively inhibit the malignant progression of esophageal cancer, gastric cancer, breast cancer, lung cancer, liver cancer, pancreatic cancer, ovarian cancer, prostate cancer, and cervical cancer. Recently, the role of oleuropein in inhibiting tumor cell proliferation, invasion, and migration and inducing tumor cell apoptosis has gained extensive attention. In this review, we have summarized the latest research progress related to the antioncogenic mechanisms and the potential role of oleuropein in targeting different human malignancies. Based on these findings, it can be concluded that oleuropein can function as a promising chemopreventive and chemotherapeutic agent against cancer, but its more detailed anticancer effects and underlying mechanisms need to be further validated in future preclinical as well as clinical studies.

Neuroprotective effects of Olea europaea L. fruit extract against cigarette smoke-induced depressive-like behaviors in Sprague-Dawley rats

Depression is broadly acclaimed as a mental health anomaly and despite advancements in the development of antidepressant drugs, they are linked with side effects. Dietary modifications and medicinal plants like olives can be used as effective strategies due to their antioxidant, immune-modulatory, antiinflammatory, and anticonvulsant properties. Considering the compositional alterations in olive fruits during ripening, the antidepressant potential of olive fruits at different degrees of ripeness, that is, un-ripened (green) and ripened (black) was investigated. Rats were randomly divided into five groups: G₀ (Normal diet), G₁ (Normal diet + smoke exposure (SE), G₂ (Normal diet + SE + Citalopram), G₃ (Normal diet + SE + Green olive extract), and G₄ (Normal diet + SE + Black olive extract). Depressive-like behaviors were induced in all groups through cigarette smoke exposure except G₀ . Green and black olive extracts prevented depressive behaviors by reducing the immobility time of rats in forced swim test and tail suspension test while increased the latency to respond in hot plate assay. Moreover, lipid peroxidation in brain tissue was reduced with citalopram, green, and black olive extracts. Additionally, treatments also enhanced the antioxidant pool of brain tissues. Histological examination revealed that olive extracts and citalopram prevented cigarette smoke-induced moderate to severe necrosis and congestion in the brain parenchyma and elucidated antidepressant potential by improving the expression of monoamine oxidase-A, solute carrier family 6 member 4, and brain-derived neurotrophic factor genes. Conclusively, olives may act as a promising antidepressant agent in ameliorating cigarette smoke-induced depressive-like behaviors. PRACTICAL APPLICATIONS: Olive extracts at both ripening stages revealed an antidepressant-like effect almost similar to the standard antidepressant drug and also prevented oxidative damages. Therefore, from the current findings, it can be recommended that food ingredients with antidepressant potential like olives should be incorporated in future interventions to combat depression/psychiatric anomalies and diet therapy should be encouraged to alleviate lifestyle-related disorders.

Polyphenols and IUGR Pregnancies: Effects of the Antioxidant Hydroxytyrosol on Brain Neurochemistry and Development in a Porcine Model

Supplementation of a mother’s diet with antioxidants, such as hydroxytyrosol (HTX), has been proposed to ameliorate the adverse phenotypes of fetuses at risk of intrauterine growth restriction. In the present study, sows were treated daily with or without 1.5 mg of HTX per kilogram of feed from day 35 of pregnancy (at 30% of total gestational period), and individuals were sampled at three different ages: 100-day-old fetuses and 1-month- and 6-month-old piglets. After euthanasia, the brain was removed and the hippocampus, amygdala, and prefrontal cortex were dissected. The profile of the catecholaminergic and serotoninergic neurotransmitters (NTs) was characterized and an immunohistochemical study of the hippocampus was performed. The results indicated that maternal supplementation with HTX during pregnancy affected the NT profile in a brain-area-dependant mode and it modified the process of neuron differentiation in the hippocampal CA1 and GD areas, indicating that cell differentiation occurred more rapidly in the HTX group. These effects were specific to the fetal period, concomitantly with HTX maternal supplementation, since no major differences remained between the control and treated groups in 1-month- and 6-month-old pigs.