Bromelain as a natural anti-inflammatory drug: a systematic review.

Inflammation is a complex and necessary mechanism of an organ's response to biological, chemical and/or physical stimuli. In recent years, investigations on natural compounds with therapeutic actions for the treatment of different diseases have increased. Among these compounds, bromelain is highlighted, as a cysteine protease isolated from the Ananas comosus (pineapple) stem. This review aimed to evaluate the anti-inflammatory activity of bromelain, as well as its pathways on inflammatory mediators, through a systematic review with in vitro studies on different cell lines. The search was performed in PubMed, Science Direct, Scopus, Cochrane Library and Web of Science databases. Bromelain reduced IL-1ß, IL-6 and TNF-α secretion when immune cells were already stimulated in an overproduction condition by proinflammatory cytokines, generating a modulation in the inflammatory response through prostaglandins reduction and activation of a cascade reactions that trigger neutrophils and macrophages, in addition to accelerating the healing process.

Application of nanoformulations as a strategy to optimize chemotherapeutic treatment of glioblastoma: a systematic review.

The aim of this review was to explore the advances of nanoformulations as a strategy to optimize glioblastoma treatment, specifically focusing on targeting and controlling drug delivery systems to the tumor. This review followed the PRISMA recommendations. The studies were selected through a literature search conducted in the electronic databases PubMed Central, Science Direct, Scopus and Web of Science, in April 2023, using the equation descriptors: (nanocapsule OR nanoformulation) AND (glioblastoma). Forty-seven investigations included were published between 2011 and 2023 to assess the application of different nanoformulations to optimize delivery of chemotherapies including temozolomide, carmustine, vincristine or cisplatin previously employed in brain tumor therapy, as well as investigating another 10 drugs. Data demonstrated the possible application of different matrices employed as nanocarriers and utilization of functionalizing agents to improve internalization of chemotherapeutics. Functionalization was developed with the application of peptides, micronutrients/vitamins, antibodies and siRNAs. Finally, this review demonstrated the practical and clinical application of nanocarriers to deliver multiple drugs in glioblastoma models. These nanomodels might ideally be developed using functionalizing ligand agents that preferably act synergistically with the drug these agents carry. The findings showed promising results, making nanoformulations one of the best prospects for innovation and improvement of glioblastoma treatment.

Dietary restriction and hepatic cancer: Systematic review and meta-analysis of animal studies.

The effect of calorie restriction, fasting, and ketogenic diets on the treatment of liver cancer remains uncertain. Therefore, we conducted a systematic review to evaluate the effect of restrictive diets on the development and progression of liver cancer in animal models. We did a meta-analysis using the Cochrane Collaboration's Review Manager software, with the random effects model and the inverse variance technique. We examined 19 studies that were conducted between 1983 and 2020. Of these, 63.2% investigated calorie restriction, 21.0% experimented with a ketogenic diet, and 15.8% investigated the effects of fasting. The intervention lasted anything from 48 h to 221 weeks. Results showed that restrictive diets may reduce tumor incidence and progression, with a significant reduction in the risk of liver cancer development. Thereby, our results suggest that putting limits on what you eat may help treat liver cancer in more ways than one.

Bromelain supplementation and inflammatory markers: A systematic review of clinical trials.

BACKGROUND AND AIMS: The inflammatory process is a response mechanism to any stressor agent. Emerging novel therapeutic options derived mainly from natural products such as bromelain have been used to reduce the significant side effects of available anti-inflammatory drugs. Bromelain is an enzyme complex derived from Ananas comosus, known for its anti-inflammatory potential and good tolerance. Therefore, the aim was to assess whether bromelain supplementation exerts anti-inflammatory effects in adults. METHODS: The systematic review was registered in PROSPERO (n° CRD42020221395), and the search was performed in MEDLINE, Scopus, Web of Science, and Cochrane Library. The terms used in the search were: "bromelains", "bromelain", "randomized clinical trial", and "clinical trial". Eligibility criteria were: randomized clinical trials with participants aged 18 years or over, of both sexes, who received supplementation with bromelain alone or in combination with other oral compounds, with an evaluation of inflammatory parameters as primary and secondary outcomes, published in English, Portuguese or Spanish. RESULTS: 1375 studies were retrieved, of which 269 were duplicates. Seven (7) randomized controlled trials were eligible for the systematic review. In most studies, supplementation with bromelain, isolated or in combined therapy, reduced inflammatory parameters. Regarding the reduction of inflammatory parameters among studies with associated bromelain, two presented reduction of inflammatory parameters, while in the evaluation of bromelain treated alone, two studies also showed reduction. In relation to doses supplemented, the studies with associated bromelain ranged from 99.9 to 1200 mg/day and the supplementation time ranged from 3 to 16 weeks. Moreover, the inflammatory parameters evaluated were: IL-12, PGE-2, COX-2, IL-6, IL-8, TNF-α, IL-1ß, IL-10, CRP, NFγ B1, PPAR-α, TNF, TRAF, MCP-1 and adiponectin. In studies with isolated bromelain supplementation, it ranged from 200 to 1050 mg/day for 1 week to 16 weeks. Markers associated with inflammation varied between studies, including IL-2, IL-5, IL-6, IL-8, IL-10, IL-13, IFNγ and MCP-1, PGE-2, CRP and fibrinogen. Eleven (11) participants experienced side effects, and two discontinued treatment in the studies. The reported adverse effects were mainly gastrointestinal but well tolerated. CONCLUSION: The general effect of bromelain supplementation on inflammation is inconsistent because of population heterogeneity, doses used, treatment duration, and parameters evaluated. The observed effects are punctual and isolated, and further standardization is needed to establish doses, supplementation time, and which type of inflammatory condition is indicated.

Consumption and supplementation of vitamin E in breast cancer risk, treatment, and outcomes: A systematic review with meta-analysis.

BACKGROUND: Robust evidence have shown diet or dietary components in playing a direct role on cancer chemoprevention such as breast cancer (BC), and also prevention against cancer therapy side effects. In this context, vitamin E isoforms have been associated with tumor suppression pathways, mainly related to proliferation, invasion, metastasis, tumor metabolism and chemoresistance. OBJECTIVE: Therefore, we performed a systematic review with meta-analysis to assess the effects of vitamin E consumption and/or supplementation on breast cancer risk, treatment, and outcomes. METHODS: The studies were selected in the electronic databases PubMed, Science Direct, Scopus and Web of Science. RESULTS: A total of 22 articles were selected, which nine manuscripts we perform the meta-analysis. The summary effect estimate did not indicate any significant association between consumption versus non-consumption of total vitamin E and breast cancer risk. After assessing the effects of vitamin E supplementation on breast cancer risk, only two had data for comparison and vitamin E supplementation presented no impact on breast cancer risk. However, the summary effect estimate from the included studies indicated that vitamin E consumption was inversely associated with breast cancer recurrence in the control group. There are no significant results regarding dietary or supplemental vitamin E intake and BC risk reduction. CONCLUSION: Finally, regarding recurrence, survival, and mortality, the results indicated that vitamin E consumption was inversely associated with breast cancer recurrence, although no association was found for breast cancer mortality.

α-tocopherol as a selective modulator of toxicogenic damage induced by antineoplastic agents cyclophosphamide and doxorubicin.

The aim of this study was to determine the oxidative/antioxidative effects, modulatory and selective potential of α-tocopherol (vitamin E) on antineoplastic drug-induced toxicogenetic damage. The toxicity, cytotoxicity and genotoxicity induced by antineoplastic agents cyclophosphamide (CPA) and doxorubicin (DOX) was examined utilizing as models Saccharomyces cerevisiae, Allium cepa, Artemia salina and human peripheral blood mononuclear cells (PBMCs) in the presence of α-tocopherol. For these tests, concentrations of α- tocopherol 100 IU/ml (67mg/ml), CPA 20 µg/ml, DOX 2 µg/ml were used. The selectivity of α-tocopherol was assessed by the MTT test using human mammary gland non-tumor (MCF10A) and tumor (MCF-7) cell lines. Data showed cytoplasmic and mitochondrial oxidative damage induced by CPA or DOX was significantly diminished by α-tocopherol in S. cerevisiae. In addition, the toxic effects on A. salina and cytotoxic and mutagenic effects on A. cepa were significantly reduced by α-tocopherol. In PBMCs, α-tocopherol alone did not markedly affect these cells, and when treated in conjunction with CPA or DOX, α-tocopherol reduced the toxicogenetic effects noted after antineoplastic drug administration as evidenced by decreased chromosomal alterations and lowered cell death rate. In human mammary gland non-tumor and tumor cell lines, α-tocopherol produced selective cytotoxicity with 2-fold higher effect in tumor cells. Evidence indicates that vitamin E (1) produced anti-cytotoxic and anti-mutagenic effects against CPA and DOX (2) increased higher selectivity toward tumor cells, and (3) presented chemoprotective activity in PBMCs.

Chemopreventive and anti-tumor potential of vitamin E in preclinical breast cancer studies: A systematic review.

BACKGROUND: Vitamin E has been investigated for its antitumor potential, including the ability to change cancer gene pathways as well as promote antioxidant and pro-oxidant activity. OBJECTIVE: Therefore, this systematic review aimed to evaluate antitumor and chemopreventive activity of different vitamin E isoforms (tocopherols and tocotrienols) through in vitro and in vivo studies. METHOD: The systematic review was registered in PROSPERO (No. CRD4202126207) and the search was carried out in four electronic databases (PubMed, Science Direct, Scopus and Web of Science) in June 2021 by three independent reviewers. The search equation used was: "Supplementation" AND ("Vitamin E" OR Tocopherol OR Tocotrienol) AND "breast cancer" AND (chemotherapy OR therapy OR prevention). In vitro studies and animal models of breast cancer supplemented with tocopherol or tocotrienol vitamers, alone or in combination, were included. RESULTS: The results revealed 8546 relevant studies that were initially identified in our search. After analysis, a total of 12 studies were eligible for this systematic review. All studies included animal models, and 5 of them also performed in vitro experiments on cancer cell lines. The studies performed supplementation with tocopherols, mixtures (tocopherols and tocotrienols) and synthetic vitamin E forms. There was an significant association of estradiol, dendritic cells and pterostilbene in combined therapy with vitamin E. Vitamin E delayed tumor development, reduced tumor size, proliferation, viability, expression of anti-apoptotic and cell proliferation genes, and upregulated pro-apoptotic genes, tumor suppressor genes and increased immune response. The effects on oxidative stress markers and antioxidant activity were conflicting among studies. Only one study with synthetic vitamin E reported cardiotoxicity, but it did not show vitamin E genotoxicity. CONCLUSION: In conclusion, vitamin E isoforms, isolated or associated, showed antitumor and chemopreventive activity. However, due to studies heterogeneity, there is a need for further analysis to establish dose, form, supplementation time and breast cancer stage.

Cellular reprogramming, chemoresistance, and dietary interventions in breast cancer.

Breast cancer (BC) diagnosis has been associated with significant risk factors, including family history, late menopause, obesity, poor eating habits, and alcoholism. Despite the advances in the last decades regarding cancer treatment, some obstacles still hinder the effectiveness of therapy. For example, chemotherapy resistance is common in locally advanced or metastatic cancer, reducing treatment options and contributing to mortality. In this review, we provide an overview of BC metabolic changes, including the impact of restrictive diets associated with chemoresistance, the therapeutic potential of the diet on tumor progression, pathways related to metabolic health in oncology, and perspectives on the future in the area of oncological nutrition.

Food consumption of branched chain amino acids and insulin resistance: A systematic review of observational studies in humans.

This review systematically investigated observational studies in humans that evaluated the dietary intake of branched-chain amino acids (BCAA) and its association with insulin resistance. A search implemented through the electronic databases of PubMed, Scopus, and Web of Science. The evaluation of insulin resistance or the risk of developing insulin resistance in humans were the variables of interest in the search for articles. After using the selection criteria, three studies included in this review. The Food Frequency Questionnaire (FFQ) was the instrument used to evaluate the diet in all of the selected studies. Overall, 1940 studies identified and three thoroughly reviewed. We found only one study with positive effects of BCAA on insulin resistance; the other two reviewed studies did not demonstrate positive effects of the dietary intake of BCAA, individually or the sum of three amino acids on variables of interest. In this sense, the associations between BCAA and insulin resistance are inconsistent, potentially due to other longitudinal outcomes.