The olive tree (Olea europaea) and olive oil hold significant cultural and historical importance in Europe. The health benefits associated with olive oil consumption have been well documented. This paper explores the mechanisms of the anti-cancer effects of olive oil and olive leaf, focusing on their key bioactive compounds, namely oleocanthal, oleacein, and oleuropein. The chemopreventive potential of oleocanthal, oleacein, and oleuropein is comprehensively examined through this systematic review. We conducted a systematic literature search to identify eligible articles from Scopus, PubMed, and Web of Science databases published up to 10 October 2023. Among 4037 identified articles, there were 88 eligible articles describing mechanisms of chemopreventive effects of oleocanthal, oleacein, and oleuropein. These compounds have the ability to inhibit cell proliferation, induce cell death (apoptosis, autophagy, and necrosis), inhibit angiogenesis, suppress tumor metastasis, and modulate cancer-associated signalling pathways. Additionally, oleocanthal and oleuropein were also reported to disrupt redox hemostasis. This review provides insights into the chemopreventive mechanisms of O. europaea-derived secoiridoids, shedding light on their role in chemoprevention. The bioactivities summarized in the paper support the epidemiological evidence demonstrating a negative correlation between olive oil consumption and cancer risk. Furthermore, the mapped and summarized secondary signalling pathways may provide information to elucidate new synergies with other chemopreventive agents to complement chemotherapies and develop novel nutrition-based anti-cancer approaches.

UNASSIGNED: Published literature shows mixed reports of the benefits of nonsteroidal anti-inflammatory drugs (NSAIDs) on reducing colorectal polyps in patients with familial adenomatous polyposis (FAP). We conducted a systematic review and performed a meta-analysis to assess the impact of NSAIDs on colorectal polyp burden in patients with FAP.
UNASSIGNED: We searched PubMed, EMBASE, and Cochrane for randomized controlled trials (RCTs) comparing the effect of NSAIDs vs placebo on the percent change in polyp number and polyp size in patients with FAP. Mean differences between the 2 study arms were pooled using RevMan. The risk of bias (RoB) was assessed using the Cochrane Risk of Bias tool for RCTs, and certainty in the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation methodology.
UNASSIGNED: The search strategy identified 1021 studies, out of which we included 8 RCTs with a total of 279 patients. Treatment for 6.4 ± 2.2 months with NSAIDs reduced polyp numbers by -17.4% (95% confidence interval -26.41%, -8.29%) (low certainty [I2 89%] due to imprecision and issues with RoB) and polyp size by -15.9% (95% confidence interval -24.98%, -6.73%) (very low certainty (I2 84%) due to imprecision, inconsistency, and issues with RoB). The most common gastrointestinal adverse events reported were stomatitis, diarrhea, and abdominal pain. Side effects leading to drug discontinuation were gastroenteritis and drug allergy.
UNASSIGNED: Short-term use of NSAIDs reduced polyp number and polyp size but with low to very low certainty of evidence. Further large multicenter studies are needed to further explore NSAIDs as a chemopreventive measure in patients with FAP.

MicroRNAs are short non-coding RNAs that inhibit gene expression at the post-transcriptional level. Abnormal microRNA expression has been associated with different human diseases, including cancer. Epigenetic changes, mutation, transcriptional deregulation, DNA copy number abnormalities, and defects in the biogenesis machinery play an important role in abnormal microRNA expression. Modulation of microRNAs by natural agents has emerged to enhance the efficacy of conventional chemotherapy through combinatorial therapeutic approach. This review summarizes the current understanding of abnormal microRNA expression in cancer, the different cellular mechanisms of microRNA, and their prevention by natural compounds. Understanding microRNA expression patterns during cancer development may help to identify stage-specific molecular markers. Natural compounds that exert regulatory effects by modulating microRNAs can be used in better cancer chemopreventive strategies by directly targeting microRNAs or as a way to increase sensitivity to existing chemotherapy regimens.

Plants from the Fabaceae family are widely distributed around the world, especially in Europe, Asia and North America. They are a rich source of isoflavones, compounds with estrogen-like activity, which are suspected of having a chemopreventive effect against hormone-dependent cancers. Following the PRISMA guidelines, we conducted a systematic review aimed at assessing the impact of Fabaceae plant extracts on hormone-dependent cancer cells and the content of active compounds in plant raw materials. We analyzed the results of 63 articles from in vitro and in vivo studies describing the effect of plant extracts containing isoflavones on cancer cells, along with their anti-inflammatory and antioxidant potential. In the process, we determined the research limitations and future research directions. The collected results indicate the plant species with potentially high contents of phytoestrogens and anti-inflammatory, antioxidant and cytotoxic properties. They point to the potential use of plants in the diet as a source of compounds offering cancer prevention.

Rising melanoma rates have spurred interest in preventive strategies. Nonsteroidal anti-inflammatory drugs (NSAIDs), particularly aspirin, show potential in reducing cancer risks. NSAIDs act on cyclooxygenase (COX) enzymes, impacting COX-2 associated with inflammation and cancer progression. This paper explores aspirin\'s role in cutaneous melanoma prevention, elucidating its mechanisms and acknowledging varying literature outcomes. Rather than providing conclusive recommendations, the review emphasizes the influence of individual factors, contributing to the ongoing dialogue on aspirin\'s complexities in melanoma prevention. A PubMed search using \"Aspirin\" AND \"Cutaneous melanoma\" yielded relevant English-language, peer-reviewed studies. Selection criteria focused exclusively on skin cancers, specifically cutaneous melanoma. Exclusions included studies covering various cancers, some non-dermatologic, and those not evaluating aspirin use independently but in conjunction with NSAIDs. The potential chemopreventive effects of aspirin and NSAIDs against melanoma have gained attention due to their association with a reduced risk of various cancers including gastric, colorectal, and breast. By inhibiting COX enzymes and the NF-κB pathway, these agents theoretically slow malignant cell activities, presenting a prospect for cancer prevention. Aspirin exhibits noteworthy effects, depleting growth-stimulating hormones, generating reactive oxygen species harmful to cancerous cells, and inhibiting COX-2 linked to cancer progression. Limited literature suggests survival benefits with aspirin use in stage II and III melanoma, possibly due to slowing disease progression, evident in smaller Breslow depths. Gender-specific responses to aspirin are notable, with some studies reporting a stronger chemopreventive correlation in females. It\'s crucial to note that geographic disparities, demographic cohorts, and individual-specific factors are confounding variables that may contribute to conflicting findings regarding aspirin\'s impact on melanoma. The association between aspirin use and melanoma risk is complex, with conflicting findings across diverse populations. Although it appears that more studies suggest a protective role for aspirin rather than not, evidence lacks consistency. Factors such as gender, geography, race, sun exposure, and health conditions play a role in shaping these varied outcomes, necessitating large-scale, prospective studies research and standardized parameters for more conclusive insights that may help guide tailored clinical strategies for melanoma prevention.

Malignant tumors are the second most common cause of death worldwide. More attention is being paid to the link between the body\'s impaired oxidoreductive balance and cancer incidence. Much attention is being paid to polyphenols derived from plants, as one of their properties is an antioxidant character: the ability to eliminate reactive oxygen and nitrogen species, chelate specific metal ions, modulate signaling pathways affecting inflammation, and raise the level and activity of antioxidant enzymes while lowering those with oxidative effects. The following three compounds, resveratrol, quercetin, and curcumin, are polyphenols modulating multiple molecular targets, or increasing pro-apoptotic protein expression levels and decreasing anti-apoptotic protein expression levels. Experiments conducted in vitro and in vivo on animals and humans suggest using them as chemopreventive agents based on antioxidant properties. The advantage of these natural polyphenols is low toxicity and weak adverse effects at higher doses. However, the compounds discussed are characterized by low bioavailability and solubility, which may make achieving the blood concentrations needed for the desired effect challenging. The solution may lie in derivatives of naturally occurring polyphenols subjected to structural modifications that enhance their beneficial effects or work on implementing new ways of delivering antioxidants that improve their solubility and bioavailability.

Isothiocyanates are biologically active products resulting from the hydrolysis of glucosinolates predominantly present in cruciferous vegetables belonging to the Brassicaceae family. Numerous studies have demonstrated the diverse bioactivities of various isothiocyanates, encompassing anticarcinogenic, anti-inflammatory, and antioxidative properties. Nature harbors distinct isothiocyanate precursors, glucosinolates such as glucoraphanin and gluconastrin, each characterized by unique structures, physical properties, and pharmacological potentials. This comprehensive review aims to consolidate the current understanding of Moringa isothiocyanates, mainly 4-[(α-L-rhamnosyloxy) benzyl] isothiocyanate), comparing this compound with other well-studied isothiocyanates such as sulforaphane and phenyl ethyl isothiocyanates. The focus is directed toward elucidating differences and similarities in the efficacy of these compounds as agents with anticancer, anti-inflammatory, and antioxidative properties.

BACKGROUND: Nicotinamide is the active form of vitamin B3 (niacin) obtained through endogenous synthesis, mainly through tryptophan metabolism and dietary supplements, fish, meats, grains, and dairy products. It participates in cellular energy metabolism and modulates multiple cellular survival and death pathways. Nicotinamide has been widely studied as a safe chemopreventive agent that reduces actinic keratosis (AKs) and non-melanoma skin cancers (NMSC).
METHODS: We used the Medline, EMBASE, PubMed, and Cochrane databases to search the concepts \"nicotinamide\", \"chemoprevention\", and \"skin cancer\" up to August 2023. Three independent authors screened titles and abstracts for intervention and study design before searching full texts for eligibility criteria. The primary outcome was the impact of oral nicotinamide on the incidence of NMSC in high-risk patients. We also conducted a systematic search to identify relevant epidemiological studies published evaluating dietary niacin intake and the risk of NMSC.
RESULTS: Two hundred and twenty-five studies were reviewed, and four met the inclusion criteria. There was no association between NAM consumption and risk for squamous cell carcinoma (SCC) (rate ratio (RR) 0.81, 95% CI 0.48-1.37; I2 = 0%), basal cell carcinoma (BCC) (RR 0.88, 95% CI 0.50-1.55; I2 = 63%), and NMSC (RR 0.82, 95% CI 0.61-1.12; I2 = 63%). Adverse events were rare and acceptable, allowing optimal compliance of patients to the treatment. We found only one article evaluating the association between niacin dietary intake and NMSC risk, supporting a potential beneficial role of niacin intake concerning SCC but not BCC or melanoma.
CONCLUSIONS: The present meta-analysis shows, by pooling immunocompetent and immunosuppressed patients, that there is insufficient evidence that oral nicotinamide therapy significantly reduces the number of keratinocyte cancers.

BACKGROUND: Severe anaemia is associated with high in-hospital mortality among young children. In malaria-endemic areas, surviving children also have an increased risk of mortality or readmission after hospital discharge. We conducted a systematic review and individual patient data meta-analysis to determine the efficacy of monthly post-discharge malaria chemoprevention in children recovering from severe anaemia.
METHODS: This analysis was conducted according to PRISMA-IPD guidelines. We searched multiple databases on Aug 28, 2023, without date or language restrictions, for randomised controlled trials comparing monthly post-discharge malaria chemoprevention with placebo or standard of care among children (aged <15 years) admitted with severe anaemia in malaria-endemic Africa. Trials using daily or weekly malaria prophylaxis were not eligible. The investigators from all eligible trials shared pseudonymised datasets, which were standardised and merged for analysis. The primary outcome was all-cause mortality during the intervention period. Analyses were performed in the modified intention-to-treat population, including all randomly assigned participants who contributed to the endpoint. Fixed-effects two-stage meta-analysis of risk ratios (RRs) was used to generate pooled effect estimates for mortality. Recurrent time-to-event data (readmissions or clinic visits) were analysed using one-stage mixed-effects Prentice-Williams-Peterson total-time models to obtain hazard ratios (HRs). This study is registered with PROSPERO, CRD42022308791.
RESULTS: Our search identified 91 articles, of which 78 were excluded by title and abstract, and a further ten did not meet eligibility criteria. Three double-blind, placebo-controlled trials, including 3663 children with severe anaemia, were included in the systematic review and meta-analysis; 3507 (95·7%) contributed to the modified intention-to-treat analysis. Participants received monthly sulfadoxine-pyrimethamine until the end of the malaria transmission season (mean 3·1 courses per child [range 1-6]; n=1085; The Gambia), monthly artemether-lumefantrine given at the end of weeks 4 and 8 post discharge (n=1373; Malawi), or monthly dihydroartemisinin-piperaquine given at the end of weeks 2, 6, and 10 post discharge (n=1049; Uganda and Kenya). During the intervention period, post-discharge malaria chemoprevention was associated with a 77% reduction in mortality (RR 0·23 [95% CI 0·08-0·70], p=0·0094, I2=0%) and a 55% reduction in all-cause readmissions (HR 0·45 [95% CI 0·36-0·56], p<0·0001) compared with placebo. The protective effect was restricted to the intervention period and was not sustained after the direct pharmacodynamic effect of the drugs had waned. The small number of trials limited our ability to assess heterogeneity, its sources, and publication bias.
CONCLUSIONS: In malaria-endemic Africa, post-discharge malaria chemoprevention reduces mortality and readmissions in recently discharged children recovering from severe anaemia. Post-discharge malaria chemoprevention could be a valuable strategy for the management of this group at high risk. Future research should focus on methods of delivery, options to prolong the protection duration, other hospitalised groups at high risk, and interventions targeting non-malarial causes of post-discharge morbidity.
BACKGROUND: The Research-Council of Norway and the Bill-&-Melinda-Gates-Foundation through the Worldwide-Antimalarial-Research-Network.

Malaria remains a leading cause of childhood morbidity and mortality in sub-Saharan Africa, particularly among children under 5 years of age. To help address this challenge, the WHO recommends chemoprevention for certain populations. For children and infants, the WHO recommends seasonal malaria chemoprevention (SMC), perennial malaria chemoprevention (PMC; formerly intermittent preventive treatment in infants [IPTi]), and, more recently, intermittent preventive treatment in school children (IPTsc). This review describes the contextual factors, including feasibility, acceptability, health equity, financial considerations, and values and preferences, that impact implementation of these strategies. A systematic search was conducted on July 5, 2022, and repeated April 13, 2023, to identify relevant literature. Two reviewers independently screened titles for eligibility, extracted data from eligible articles, and identified and summarized themes. Of 6,295 unique titles identified, 65 were included. The most frequently evaluated strategy was SMC (n = 40), followed by IPTi (n = 18) and then IPTsc (n = 6). Overall, these strategies were highly acceptable, although with IPTsc, there were community concerns with providing drugs to girls of reproductive age and the use of nonmedical staff for drug distribution. For SMC, door-to-door delivery resulted in higher coverage, improved caregiver acceptance, and reduced cost. Lower adherence was noted when caregivers were charged with giving doses 2 and 3 unsupervised. For SMC and IPTi, travel distances and inclement weather limited accessibility. Sensitization and caregiver education efforts, retention of high-quality drug distributors, and improved transportation were key to improving coverage. Additional research is needed to understand the role of community values and preferences in chemoprevention implementation.