Salicylic acid metabolites and derivatives inhibit CDK activity: Novel insights into aspirin's chemopreventive effects against colorectal cancer

The Puzzle of Aspirin and Iron Deficiency: The Vital Missing Link of the Iron-Chelating Metabolites

Acetylsalicylic acid or aspirin is the most commonly used drug in the world and is taken daily by millions of people. There is increasing evidence that chronic administration of low-dose aspirin of about 75-100 mg/day can cause iron deficiency anaemia (IDA) in the absence of major gastric bleeding; this is found in a large number of about 20% otherwise healthy elderly (>65 years) individuals. The mechanisms of the cause of IDA in this category of individuals are still largely unknown. Evidence is presented suggesting that a likely cause of IDA in this category of aspirin users is the chelation activity and increased excretion of iron caused by aspirin chelating metabolites (ACMs). It is estimated that 90% of oral aspirin is metabolized into about 70% of the ACMs salicyluric acid, salicylic acid, 2,5-dihydroxybenzoic acid, and 2,3-dihydroxybenzoic acid. All ACMs have a high affinity for binding iron and ability to mobilize iron from different iron pools, causing an overall net increase in iron excretion and altering iron balance. Interestingly, 2,3-dihydroxybenzoic acid has been previously tested in iron-loaded thalassaemia patients, leading to substantial increases in iron excretion. The daily administration of low-dose aspirin for long-term periods is likely to enhance the overall iron excretion in small increments each time due to the combined iron mobilization effect of the ACM. In particular, IDA is likely to occur mainly in populations such as elderly vegetarian adults with meals low in iron content. Furthermore, IDA may be exacerbated by the combinations of ACM with other dietary components, which can prevent iron absorption and enhance iron excretion. Overall, aspirin is acting as a chelating pro-drug similar to dexrazoxane, and the ACM as combination chelation therapy. Iron balance, pharmacological, and other studies on the interaction of iron and aspirin, as well as ACM, are likely to shed more light on the mechanism of IDA. Similar mechanisms of iron chelation through ACM may also be implicated in patient improvements observed in cancer, neurodegenerative, and other disease categories when treated long-term with daily aspirin. In particular, the role of aspirin and ACM in iron metabolism and free radical pathology includes ferroptosis, and may identify other missing links in the therapeutic effects of aspirin in many more diseases. It is suggested that aspirin is the first non-chelating drug described to cause IDA through its ACM metabolites. The therapeutic, pharmacological, toxicological and other implications of aspirin are incomplete without taking into consideration the iron binding and other effects of the ACM.

Analysis of differences in intestinal flora associated with different BMI status in colorectal cancer patients

BACKGROUND

Overweight is known to be an important risk factor for colorectal cancer (CRC), and the differences in intestinal flora among CRC patients with different BMI status have not been clearly defined. The purpose of this study was to elucidate the differences in the abundance, composition and biological function of intestinal flora in CRC patients with different BMI status.

METHOD

A total of 170 CRC patients were included and grouped according to the BMI data of CRC patients. BMI ≥ 24 kg/m2 was defined as overweight group, and BMI within the range of 18.5-23.9 kg/m2 was defined as normal weight group. Preoperative stool collection of patients in both groups was used for 16S rRNA sequencing. Total RNA was extracted from 17 CRC tumor tissue samples for transcriptome sequencing, and then CIBERSORT algorithm was used to convert the transcriptome data into the relative content matrix of 22 kinds of immune cells, and the correlation between different intestinal flora and immune cells and immune-related genes under different BMI states was analyzed. Finally, we identified BMI-related differential functional pathways and analyzed the correlation between these pathways and differential intestinal flora.

RESULT

There was no significant difference in α diversity and β diversity analysis between overweight group and normal weight group. Partial least square discriminant analysis (PLS-DA) could divide the flora into two different clusters according to BMI stratification. A total of 33 BMI-related differential flora were identified by linear discriminant effect size analysis (LEfSe), among which Actinomyces, Desulfovibrio and Bacteroides were significantly enriched in overweight group. ko00514: Other types of O-glycan biosynthesis are significantly enriched in overweight group. There was a significant positive correlation between Clostridium IV and Macrophages M2 and T cells regulatory (Tregs). There was a significant negative correlation with Dendritic cells activated and T cells CD4 memory activated.

CONCLUSIONS

The richness and diversity of intestinal flora of CRC patients may be related to different BMI status, and the enrichment of Actinomyces, Desulphurvibrio and Bacteroides may be related to overweight status of CRC patients. The tumor microenvironment in which BMI-related differential flora resides has different immune landscapes, suggesting that some intestinal flora may affect the biological process of CRC by regulating immune cell infiltration and immune gene expression, but further experiments are needed to confirm this.

Interkingdom Hormonal Regulations between Plants and Animals Provide New Insight into Food Safety

Food safety has become an attractive topic among consumers. Raw material production for food is also a focus of social attention. As hormones are widely used in agriculture and human disease control, consumers' concerns about the safety of hormone agents have never disappeared. The present review focuses on the interkingdom regulations of exogenous animal hormones in plants and phytohormones in animals, including physiology and stress resistance. We summarize these interactions to give the public, researchers, and policymakers some guidance and suggestions. Accumulated evidence demonstrates comprehensive hormonal regulation across plants and animals. Animal hormones, interacting with phytohormones, help regulate plant development and enhance environmental resistance. Correspondingly, phytohormones may also cause damage to the reproductive and urinary systems of animals. Notably, the disease-resistant role of phytohormones is revealed against neurodegenerative diseases, cardiovascular disease, cancer, and diabetes. These resistances derive from the control for abnormal cell cycle, energy balance, and activity of enzymes. Further exploration of these cross-kingdom mechanisms would surely be of greater benefit to human health and agriculture development.

Short salsalate administration affects cell proliferation, metabolism, and inflammation in polycystic kidney disease

Metabolic reprogramming is a driver of autosomal dominant polycystic kidney disease (ADPKD) progression and a potential therapeutic intervention route. We showed before that the AMP-associated protein kinase (AMPK) activator salsalate attenuates cystic disease progression. Here, we aim to study the early, direct effects of short salsalate treatment in adult-onset conditional Pkd1 deletion mice. Cystic mice were treated with salsalate for two weeks, after which NMR metabolomics and RNA sequencing analyses were performed. Pkd1 deletion resulted in clear metabolomic dysregulation. Short salsalate treatment has small, but significant, effects, reverting acetylcarnitine and phosphocholine concentrations back to wildtype levels, and showing associations with altered purine metabolism. RNA sequencing revealed that short salsalate treatment, next to restoring energy metabolism toward wildtype levels, also affects cell proliferation and inflammation, in PKD. We show that salsalate positively affects major dysregulated processes in ADPKD: energy metabolism, cell proliferation, and inflammation, providing more insights into its working mechanisms.

Indomethacin Induces Spermidine/Spermine-N1-Acetyltransferase-1 via the Nucleolin-CDK1 Axis and Synergizes with the Polyamine Oxidase Inhibitor Methoctramine in Lung Cancer Cells

Indomethacin is a non-selective NSAID used against pain and inflammation. Although cyclooxygenase (COX) inhibition is considered indomethacin's primary action mechanism, COX-independent ways are associated with beneficial effects in cancer. In colon cancer cells, the activation of the peroxisome proliferator-activated receptor-γ (PPAR-γ) is related to the increase in spermidine/spermine-N1-acetyltransferase-1 (SSAT-1), a key enzyme for polyamine degradation, and related to cell cycle arrest. Indomethacin increases the SSAT-1 levels in lung cancer cells; however, the mechanism relying on the SSAT-1 increase is unclear. Thus, we asked for the influence of the PPAR-γ on the SSAT-1 expression in two lung cancer cell lines: H1299 and A549. We found that the inhibition of PPAR-γ with GW9662 did not revert the increase in SSAT-1 induced by indomethacin. Because the mRNA of SSAT-1 suffers a pre-translation retention step by nucleolin, a nucleolar protein, we explored the relationship between indomethacin and the upstream translation regulators of SSAT-1. We found that indomethacin decreases the nucleolin levels and the cyclin-dependent kinase 1 (CDK1) levels, which phosphorylates nucleolin in mitosis. Overexpression of nucleolin partially reverts the effect of indomethacin over cell viability and SSAT-1 levels. On the other hand, Casein Kinase, known for phosphorylating nucleolin during interphase, is not modified by indomethacin. SSAT-1 exerts its antiproliferative effect by acetylating polyamines, a process reverted by the polyamine oxidase (PAOX). Recently, methoctramine was described as the most specific inhibitor of PAOX. Thus, we asked if methoctramine could increase the effect of indomethacin. We found that, when combined, indomethacin and methoctramine have a synergistic effect against NSCLC cells in vitro. These results suggest that indomethacin increases the SSAT-1 levels by reducing the CDK1-nucleolin regulatory axis, and the PAOX inhibition with methoctramine could improve the antiproliferative effect of indomethacin.

Molecular Effects of Iodine-Biofortified Lettuce in Human Gastrointestinal Cancer Cells

Considering the growing number of cancer cases around the world, natural products from the diet that exhibit potential antitumor properties are of interest. Our previous research demonstrated that fortification with iodine compounds is an effective way to improve the antioxidant potential of lettuce. The purpose of the present study was to evaluate the effect of iodine-biofortified lettuce on antitumor properties in human gastrointestinal cancer cell lines, gastric AGS and colon HT-29. Our results showed that extracts from iodine-biofortified lettuce reduce the viability and proliferation of gastric and colon cancer cells. The extracts mediated cell cycle arrest which was accompanied by inactivation of anti-apoptotic Bcl-2 and activation of caspases, as assessed by flow cytometry. However, extracts from lettuce fortified with organic forms of iodine acted more effectively than extracts from control and KIO3-enriched plants. Using quantitative PCR, we detected the increase in pro-apoptotic genes BAD, BAX and BID in AGS cells whereas up-regulation of cell cycle progression inhibitor CDKN2A and downregulation of pro-proliferative MDM2 in HT-29 cells. Interestingly, lettuce extracts led to down-regulation of pro-survival AKT1 and protooncogenic MDM2, which was consistent for extracts of lettuce fortified with organic form of iodine, 5-ISA, in both cell lines. MDM2 downregulation in HT-29 colon cancer cells was associated with RB1 upregulation upon 5-ISA-fortified lettuce extracts, which provides a link to the epigenetic regulation of tumor suppressor genes by RB/MDM2 pathway. Indeed, SEMA3A tumor suppressor gene was hypomethylated and upregulated in HT-29 cells treated with 5-ISA-fortified lettuce. Control lettuce exerted similar effects on RB/MDM2 pathway and SEMA3A epigenetic activation in HT-29 cells. Our findings suggest that lettuce as well as lettuce fortified with organic form of iodine, 5-ISA, may exert epigenetic anti-cancer effects that can be cancer type-specific.

Development and Validation of an HPLC-UV Method for the Quantification of 4'-Hydroxydiclofenac Using Salicylic Acid: Future Applications for Measurement of In Vitro Drug-Drug Interaction in Rat Liver Microsomes

Salicylic acid is a key compound in nonsteroidal anti-inflammatory drugs that has been recently used for preventing the risk of hospitalization and death among COVID-19 patients and in preventing colorectal cancer (CRC) by suppressing two key proteins. Understanding drug−drug interaction pathways prevent the occurrence of adverse drug reactions in clinical trials. Drug−drug interactions can result in the variation of the pharmacodynamics and pharmacokinetic of the drug. Inhibition of the Cytochrome P450 enzyme activity leads to the withdrawal of the drug from the market. The aim of this paper was to develop and validate an HPLC-UV method for the quantification of 4′-hydroxydiclofenac as a CYP2C9 metabolite using salicylic acid as an inhibitor in rat liver microsomes. A CYP2C9 assay was developed and validated on the reversed phase C18 column (SUPELCO 25 cm × 4.6 mm × 5 µm) using a low-pressure gradient elution programming at T = 30 °C, a wavelength of 282 nm, and a flow rate of 1 mL/min. 4′-hydroxydiclofenac demonstrated a good linearity (R2 > 0.99), good reproducibility, low detection, and quantitation limit, and the inter and intra-day precision met the ICH guidelines (<15%). 4′-hydroxydiclofenac was stable for three days and showed an acceptable accuracy and recovery (80−120%) within the ICH guidelines in a rat liver microsome sample. This method will be beneficial for future applications of the in vitro inhibitory effect of salicylic acid on the CYP2C9 enzyme activity in rat microsomes and the in vivo administration of salicylic acid in clinical trials.

Dietary Intervention Effectiveness, Clinical Outcomes and Nutrient and Salicylate Intakes in Older Adults Living in Long-Term Care Homes: The Results from the Senior’s Plate Project

Optimal nutrition is an important part of the therapeutic process offered to patients in long-term care, as it can significantly influence their nutritional and health status. The aim of this study was to assess the impacts of a dietary intervention on the nutritional status, clinical outcomes and selected nutrient and salicylate intakes among older adults living in a long-term care nursing home. To achieve the research goal, a prospective, non-randomized, baseline-controlled intervention study was conducted. The study was conducted within the framework of the “Senior’s Plate Project”, a project established in 2018 by the Polish Society of Dietetics. Methods: A 3 month dietary intervention, which included one serving of supplementary food, served as a second breakfast (Nestle Sinlac). Energy, nutrients and salicylates intakes were estimated on the basis of the menus. Food and beverage intakes among residents were verified by health care personnel. Anthropometric measurements and clinical examinations were conducted according to standard procedures at baseline and after intervention. Results: Of the 38 residents qualified for the study, 29 completed the program. Residents’ body mass index (BMI) values ranged from 13.3 kg/m2 to 34 kg/m2. A BMI <22 kg/m2, indicating underweight, was found in 19 subjects. The dietary intervention resulted in increased body weight (57.8 ± 12.3 vs. 59.4 ± 12.6 kg), BMI (22.4 ± 4.0 vs. 23.0 ± 4.1 kg/m2) and body fat (19.2 ± 8.7 vs. 20.6 ± 8.9 kg). Significant changes in the levels of biochemical parameters, including serum calcium (8.7 vs. 9.5 mg/dL), potassium (4.1 ± 0.6 vs. 4.5 ± 0.5 mmol/L) and zinc (74.1 ± 10.9 vs. 109.0 ± 20.4 µg/dL), were observed. Energy, protein, fat and carbohydrate intakes were significantly higher in the third month of the intervention as compared to the baseline. The estimated medial daily intake of salicylates was low and ranged from 0.34 mg to 0.39 mg. Conclusions: The dietary intervention resulted in beneficial and significant changes in the nutritional status, biochemical parameters and nutrition of residents of the long-term care home. These results suggest that practical and individualized approaches are required to improve the nutritional status and clinical outcomes of nursing homes residents.

Metabolomic Profiling Identified Serum Metabolite Biomarkers and Related Metabolic Pathways of Colorectal Cancer

Background

The screening and early detection of colorectal cancer (CRC) still remain a challenge due to the lack of reliable and effective serum biomarkers. Thus, this study is aimed at identifying serum biomarkers of CRC that could be used to distinguish CRC from healthy controls.

Methods

A prospective 1 : 2 individual matching case-control study was performed which included 50 healthy control subjects and 98 CRC patients. Untargeted metabolomic profiling was conducted with liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify CRC-related metabolites and metabolic pathways.

Results

In total, 178 metabolites were detected, and an orthogonal partial least-squares-discriminant analysis (OPLS-DA) model was useful to distinguish CRC patients from healthy controls. Nine metabolites showed significantly differential serum levels in CRC patients under the conditions of variable importance in projection (VIP) > 1, p < 0.05 using Student's t-test, and fold change (FC) ≥ 1.2 or ≤0.5. The above nine metabolites were 3-hydroxybutyric acid, hexadecanedioic acid, succinic acid semialdehyde, 4-dodecylbenzenesulfonic acid, prostaglandin B2, 2-pyrocatechuic acid, xanthoxylin, 12-hydroxydodecanoic acid, and formylanthranilic acid. Four potential biomarkers were identified to diagnose CRC through ROC curves: hexadecanedioic acid, 4-dodecylbenzenesulfonic acid, 2-pyrocatechuic acid, and formylanthranilic acid. All AUC values of these four serum biomarkers were above 0.70. In addition, the exploratory analysis of metabolic pathways revealed the activated states for the vitamin B metabolic pathway and the alanine, aspartate, and glutamate metabolic pathways associated with CRC.

Conclusion

The 4 identified potential metabolic biomarkers could discriminate CRC patients from healthy controls, and the 2 metabolic pathways may be activated in the CRC tissues.

Identification of the Effects of Chondroitin Sulfate on Inhibiting CDKs in Colorectal Cancer Based on Bioinformatic Analysis and Experimental Validation

With a high occurrence rate and high mortality, the treatment of colorectal cancer (CRC) is increasingly attracting the attention of scholars. Hub genes that determine the phenotypes of CRC become essential for targeted therapy. In the present study, the importance of cyclin-dependent kinases (CDKs) on the occurrence of CRC was identified by data mining of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). The results showed that the gene expression levels of CDK1, CDK4, and CDK6 were obviously changed in different stages of CRC. Among the CDKs, CDK4 was suggested as an independent risk factor for CRC based on Cox analysis. Furthermore, chondroitin sulfate (CS), a kind of dietary supplement to treat osteoarthritis, was predicted to treat CRC based on its chemical structure and GEO datasets. Cell assay experiments with the human CRC cell line HCT-116 also verified this prediction. CS inhibited the gene and protein expression levels of CDKs and increased the ratios of apoptotic or dead HCT-116 cells by regulating mitogen-activated protein (MAP) kinase pathways. Our data highlight the essential roles of CDKs in CRC carcinogenesis and the effects of CS on treating CRC, both of which will contribute to the future CRC treatment.

Potential Assessment of UGT2B17 Inhibition by Salicylic Acid in Human Supersomes In Vitro

Glucuronidation is a Phase 2 metabolic pathway responsible for the metabolism and excretion of testosterone to a conjugate testosterone glucuronide. Bioavailability and the rate of anabolic steroid testosterone metabolism can be affected upon UGT glucuronidation enzyme alteration. However, there is a lack of information about the in vitro potential assessment of UGT2B17 inhibition by salicylic acid. The purpose of this study is to investigate if UGT2B17 enzyme activity is inhibited by salicylic acid. A UGT2B17 assay was developed and validated by HPLC using a C18 reversed phase column (SUPELCO 25 cm × 4.6 mm, 5 μm) at 246 nm using a gradient elution mobile phase system: (A) phosphate buffer (0.01 M) at pH = 3.8, (B) HPLC grade acetonitrile and (C) HPLC grade methanol. The UGT2B17 metabolite (testosterone glucuronide) was quantified using human UGT2B17 supersomes by a validated HPLC method. The type of inhibition was determined by Lineweaver–Burk plots. These were constructed from the in vitro inhibition of salicylic acid at different concentration levels. The UGT2B17 assay showed good linearity (R2 > 0.99), acceptable recovery and accuracy (80–120%), good reproducibility and acceptable inter and intra-assay precision (<15%), low detection (6.42 and 2.76 μM) and quantitation limit values (19.46 and 8.38 μM) for testosterone and testosterone glucuronide respectively, according to ICH guidelines. Testosterone and testosterone glucuronide were found to be stable up to 72 h in normal laboratory conditions. Our investigational study showed that salicylic acid uncompetitively inhibited UGT2B17 enzyme activity. Thus, drugs that are substrates for the UGT2B17 enzyme have negligible potential effect of causing interaction with salicylic acid in humans.

Antioxidant mediated protective effect of Bridelia tomentosa leaf extract against carbofuran induced oxidative hepatic toxicity

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Bridelia tomentosa is a traditional medicinal plant that is used against colitis, traumatic injury, diarrhea, and diabetes.

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Gallic acid, Tannic acid, salicylic acid, and naringin were isolated from the leaf of B. tomentosa for the first time.

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B. tomentosa extract amended serum biochemical markers, MDA levels, and improved the levels of hepatic antioxidant enzymes.

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Phenolic and flavonoid compounds of the B. tomentosa can be used as nutraceuticals for treating oxidative hepatic ailments.

Bridelia tomentosa (B. tomentosa) is a traditional medicinal plant for treating diverse ailments. Hence, we designed our study to scrutinize the protective effect of the methanol extract of B. tomentosa leaf (BTL) against carbofuran-induced oxidative stress-mediated hepato-toxicity in Sprague-Dawley rats for the first time, along with the identification and quantification of phenolic acids and flavonoids by high-performance liquid chromatography (HPLC) and evaluation of antioxidant and antiradical activities of this extract. HPLC analysis confirmed the existence of tannic acid, gallic acid, salicylic acid, and naringin in B. tomentosa leaf extract which showed in-vitro antioxidant potentialities with DPPH, nitric oxide, hydrogen peroxide, and hydroxyl radical scavenging properties. Co-administration of B. tomentosa leaf extract with carbofuran showed dose-dependent significant protective effects of hepatic toxicity on serum markers such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl-transferase, lactate dehydrogenase, total bilirubin, total protein, albumin, globulin, lipid profile, urea, uric acid, and creatinine. Carbofuran intoxication also revealed an upsurge in malondialdehyde (MDA) and a decline in cellular endogenous antioxidant enzyme levels in rats compared with the control group. However, B. tomentosa leaf extract co-treatment increased the levels of hepatic antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, and amended the MDA level. Similarly, histopathological evaluation further assured that BTL could keep the hepatocyte from carbofuran-induced damage. Therefore, all of our findings may conclude that the phenolic acids and flavonoids of B. tomentosa leaf extract are responsible to neutralize the toxic free radical-mediated oxidative hepatic damages.

Comprehensive Volatilome and Metabolome Signatures of Colorectal Cancer in Urine: A Systematic Review and Meta-Analysis

To increase compliance with colorectal cancer screening programs and to reduce the recommended screening age, cheaper and easy non-invasiveness alternatives to the fecal immunochemical test should be provided. Following the PRISMA procedure of studies that evaluated the metabolome and volatilome signatures of colorectal cancer in human urine samples, an exhaustive search in PubMed, Web of Science, and Scopus found 28 studies that met the required criteria. There were no restrictions on the query for the type of study, leading to not only colorectal cancer samples versus control comparison but also polyps versus control and prospective studies of surgical effects, CRC staging and comparisons of CRC with other cancers. With this systematic review, we identified up to 244 compounds in urine samples (3 shared compounds between the volatilome and metabolome), and 10 of them were relevant in more than three articles. In the meta-analysis, nine studies met the criteria for inclusion, and the results combining the case-control and the pre-/post-surgery groups, eleven compounds were found to be relevant. Four upregulated metabolites were identified, 3-hydroxybutyric acid, L-dopa, L-histidinol, and N1, N12-diacetylspermine and seven downregulated compounds were identified, pyruvic acid, hydroquinone, tartaric acid, and hippuric acid as metabolites and butyraldehyde, ether, and 1,1,6-trimethyl-1,2-dihydronaphthalene as volatiles.

Salicylic Acid Biosynthesis and Metabolism: A Divergent Pathway for Plants and Bacteria

Salicylic acid (SA) is an active secondary metabolite that occurs in bacteria, fungi, and plants. SA and its derivatives (collectively called salicylates) are synthesized from chorismate (derived from shikimate pathway). SA is considered an important phytohormone that regulates various aspects of plant growth, environmental stress, and defense responses against pathogens. Besides plants, a large number of bacterial species, such as Pseudomonas, Bacillus, Azospirillum, Salmonella, Achromobacter, Vibrio, Yersinia, and Mycobacteria, have been reported to synthesize salicylates through the NRPS/PKS biosynthetic gene clusters. This bacterial salicylate production is often linked to the biosynthesis of small ferric-ion-chelating molecules, salicyl-derived siderophores (known as catecholate) under iron-limited conditions. Although bacteria possess entirely different biosynthetic pathways from plants, they share one common biosynthetic enzyme, isochorismate synthase, which converts chorismate to isochorismate, a common precursor for synthesizing SA. Additionally, SA in plants and bacteria can undergo several modifications to carry out their specific functions. In this review, we will systematically focus on the plant and bacterial salicylate biosynthesis and its metabolism.

Effects of potential synbiotic interaction between Lactobacillus rhamnosus GG and salicylic acid on human colon and prostate cancer cells

Salicylic acid, widely distributed in the whole plant kingdom, is a benzoic acid derivative acting as a signal substance in plants, but could be related to differences in cancer incidence, as many herbs and spices contain high amounts. Lactobacillus rhamnosus GG (LGG) is one of the best-known lactic acid bacteria that has been studied for over 30 years. Probiotic and/or commensal bacteria of the human microbiota are known to respond to diet constituents. Therefore, the present study aims at investigating the possible effects of salicylic acid on the probiotic properties of LGG, and in vitro cytotoxic effects of combination of salicylic acid and LGG on human colon and prostate cancer cells. Salicylic acid significantly (p < 0.05) increased co-aggregation of LGG with E. coli (~ twofold) and anti-oxidant properties. Furthermore, it also induced the cytotoxic effects of LGG against human colon cancer cells. These results suggest that interaction of LGG with salicylic acid can exert more probiotic properties.

Mechanisms of Colorectal Cancer Prevention by Aspirin-A Literature Review and Perspective on the Role of COX-Dependent and -Independent Pathways

Aspirin, synthesized and marketed in 1897 by Bayer, is one of the most widely used drugs in the world. It has a well-recognized role in decreasing inflammation, pain and fever, and in the prevention of thrombotic cardiovascular diseases. Its anti-inflammatory and cardio-protective actions have been well studied and occur through inhibition of cyclooxygenases (COX). Interestingly, a vast amount of epidemiological, preclinical and clinical studies have revealed aspirin as a promising chemopreventive agent, particularly against colorectal cancers (CRC); however, the primary mechanism by which it decreases the occurrences of CRC has still not been established. Numerous mechanisms have been proposed for aspirin’s chemopreventive properties among which the inhibition of COX enzymes has been widely discussed. Despite the wide attention COX-inhibition has received as the most probable mechanism of cancer prevention by aspirin, it is clear that aspirin targets many other proteins and pathways, suggesting that these extra-COX targets may also be equally important in preventing CRC. In this review, we discuss the COX-dependent and -independent pathways described in literature for aspirin’s anti-cancer effects and highlight the strengths and limitations of the proposed mechanisms. Additionally, we emphasize the potential role of the metabolites of aspirin and salicylic acid (generated in the gut through microbial biotransformation) in contributing to aspirin’s chemopreventive actions. We suggest that the preferential chemopreventive effect of aspirin against CRC may be related to direct exposure of aspirin/salicylic acid or its metabolites to the colorectal tissues. Future investigations should shed light on the role of aspirin, its metabolites and the role of the gut microbiota in cancer prevention against CRC.

Intake of Dietary Salicylates from Herbs and Spices among Adult Polish Omnivores and Vegans

There is a growing body of evidence that a diet rich in bioactive compounds from herbs and spices has the ability to reduce the risk of chronic diseases. The consumption of herbs and spices is often overlooked in the studies on food intake. However, measurement of dietary intake of these products, as a source of bioactive compounds, including salicylates, has recently gained much significance. The aims of the study were (i) to assess the intake of herbs and spices at the individual level and (ii) to calculate the dietary salicylates intake from herbs and spices among adult omnivores and vegans. The study group consisted of 270 adults aged 19 to 67 years, including 205 women and 65 men. Among all, 208 individuals were following an omnivorous diet while 62 were vegans. A semi-quantitative food frequency questionnaire (FFQ) was designed to assess the habitual intake of 61 fresh and dried herbs and spices during the preceding three months. The five most frequently eaten herbs among omnivores were parsley, garlic, dill, marjoram and basil, while among vegans they were garlic, parsley, ginger, basil and dill. An average intake of all condiments included in the study was 22.4 ± 18.4 g/day and 25.8 ± 25.9 g/day for both omnivores and vegans, respectively (p = 0.007). Estimated medial salicylates intake was significantly higher among vegans (p = 0.000) and reached 5.82 mg/week vs. 3.13 mg/week for omnivores. Our study confirmed that herbs and spices are important sources of salicylates; however, the type of diet influenced their level in the diet. Vegans consume significantly more total salicylates than omnivores.

Uptake Transporters of the SLC21, SLC22A, and SLC15A Families in Anticancer Therapy-Modulators of Cellular Entry or Pharmacokinetics?

Solute carrier transporters comprise a large family of uptake transporters involved in the transmembrane transport of a wide array of endogenous substrates such as hormones, nutrients, and metabolites as well as of clinically important drugs. Several cancer therapeutics, ranging from chemotherapeutics such as topoisomerase inhibitors, DNA-intercalating drugs, and microtubule binders to targeted therapeutics such as tyrosine kinase inhibitors are substrates of solute carrier (SLC) transporters. Given that SLC transporters are expressed both in organs pivotal to drug absorption, distribution, metabolism, and elimination and in tumors, these transporters constitute determinants of cellular drug accumulation influencing intracellular drug concentration required for efficacy of the cancer treatment in tumor cells. In this review, we explore the current understanding of members of three SLC families, namely SLC21 (organic anion transporting polypeptides, OATPs), SLC22A (organic cation transporters, OCTs; organic cation/carnitine transporters, OCTNs; and organic anion transporters OATs), and SLC15A (peptide transporters, PEPTs) in the etiology of cancer, in transport of chemotherapeutic drugs, and their influence on efficacy or toxicity of pharmacotherapy. We further explore the idea to exploit the function of SLC transporters to enhance cancer cell accumulation of chemotherapeutics, which would be expected to reduce toxic side effects in healthy tissue and to improve efficacy.

Nobiletin as a Molecule for Formulation Development: An Overview of Advanced Formulation and Nanotechnology-Based Strategies of Nobiletin

Approximately 40% of compounds in clinical drug development suffer from solubility and bioavailability challenges. Evidence from literature demonstrates the growing interest to utilize flavonoids as potential compounds owing to their widespread therapeutic utility in various ailments. Nobiletin (NOB), one such dietary polymethoxylated flavonoid found in citrus fruits, has multiple pharmacological effects such as antioxidant, anti-microbial, anti-cancer, and anti-inflammatory. It is useful in cancer, inflammatory bowel diseases, atherosclerosis, obesity, and Alzheimer's disease. Although preclinical studies demonstrate the therapeutic utility of NOB, it suffers from serious biopharmaceutical limitations such as low aqueous solubility (below 1 μg/ml), poor permeability across biological barriers, and low bioavailability. To overcome these biopharmaceutical challenges associated with NOB, the use of advanced formulations and nanotechnology-based strategies appears to be a promising approach to potentiate its therapeutic action. Multiple reviews cover the various therapeutic benefits of NOB in various diseases; however, there is an absence of a comprehensive review that focuses on the formulation development strategies of NOB. The purpose of this review is to provide a concise perspective on NOB as a candidate molecule for formulation development. The manuscript covers various aspects related to NOB, such as its chemistry, physicochemical properties, and pharmacological effects. This is also a thorough review of various formulation development strategies with advances made in the past years to improve the solubility, bioavailability, and therapeutic efficacy of NOB. The review also contains information related to toxicity and patents involving NOB and its formulation.

Synergistic activation of AMPK prevents from polyglutamine-induced toxicity in Caenorhabditis elegans

Expression of abnormally long polyglutamine (polyQ) tracks is the source of a range of dominant neurodegenerative diseases, such as Huntington disease. Currently, there is no treatment for this devastating disease, although some chemicals, e.g., metformin, have been proposed as therapeutic solutions. In this work, we show that metformin, together with salicylate, can synergistically reduce the number of aggregates produced after polyQ expression in Caenorhabditis elegans. Moreover, we demonstrate that incubation polyQ-stressed worms with low doses of both chemicals restores neuronal functionality. Both substances are pleitotropic and may activate a range of different targets. However, we demonstrate in this report that the beneficial effect induced by the combination of these drugs depends entirely on the catalytic action of AMPK, since loss of function mutants of aak-2/AMPKα2 do not respond to the treatment. To further investigate the mechanism of the synergetic activity of metformin/salicylate, we used CRISPR to generate mutant alleles of the scaffolding subunit of AMPK, aakb-1/AMPKβ1. In addition, we used an RNAi strategy to silence the expression of the second AMPKβ subunit in worms, namely aakb-2/AMPKβ2. In this work, we demonstrated that both regulatory subunits of AMPK are modulators of protein homeostasis. Interestingly, only aakb-2/AMPKβ2 is required for the synergistic action of metformin/salicylate to reduce polyQ aggregation. Finally, we showed that autophagy acts downstream of metformin/salicylate-related AMPK activation to promote healthy protein homeostasis in worms.

Do Aspirin and Flavonoids Prevent Cancer through a Common Mechanism Involving Hydroxybenzoic Acids?-The Metabolite Hypothesis

Despite decades of research to elucidate the cancer preventive mechanisms of aspirin and flavonoids, a consensus has not been reached on their specific modes of action. This inability to accurately pinpoint the mechanism involved is due to the failure to differentiate the primary targets from its associated downstream responses. This review is written in the context of the recent findings on the potential pathways involved in the prevention of colorectal cancers (CRC) by aspirin and flavonoids. Recent reports have demonstrated that the aspirin metabolites 2,3-dihydroxybenzoic acid (2,3-DHBA), 2,5-dihydroxybenzoic acid (2,5-DHBA) and the flavonoid metabolites 2,4,6-trihydroxybenzoic acid (2,4,6-THBA), 3,4-dihydroxybenzoic acid (3,4-DHBA) and 3,4,5-trihydroxybenzoic acid (3,4,5-THBA) were effective in inhibiting cancer cell growth in vitro. Limited in vivo studies also provide evidence that some of these hydroxybenzoic acids (HBAs) inhibit tumor growth in animal models. This raises the possibility that a common pathway involving HBAs may be responsible for the observed cancer preventive actions of aspirin and flavonoids. Since substantial amounts of aspirin and flavonoids are left unabsorbed in the intestinal lumen upon oral consumption, they may be subjected to degradation by the host and bacterial enzymes, generating simpler phenolic acids contributing to the prevention of CRC. Interestingly, these HBAs are also abundantly present in fruits and vegetables. Therefore, we suggest that the HBAs produced through microbial degradation of aspirin and flavonoids or those consumed through the diet may be common mediators of CRC prevention.

Novel benzoate-lipophilic cations selectively induce cell death in human colorectal cancer cell lines

INTRODUCTION

Colorectal cancer (CRC) is a critical health issue worldwide. The high rate of liver and lung metastasis associated with CRC creates a significant barrier to effective and efficient therapy. Tumour cells, including CRC cells, have metabolic alterations, such as high levels of glycolytic activity, increased cell proliferation and invasiveness, and chemo- and radio-resistance. However, the abnormally elevated mitochondrial transmembrane potential of these cells also provides an opportunity to develop drugs that selectively target the mitochondrial functions of tumour cells.

METHODS

In this work, we used a new batch of benzoic acid esters with cytotoxic activities attached to the triphenylphosphonium group as a vehicle to target tumour mitochondria and improve their activity. We evaluated the cytotoxicity, selectivity, and mechanism of action of these derivatives, including the effects on energy stress-induced apoptosis and metabolic behaviour in the human CRC cell lines HCT-15 and COLO-205.

RESULTS

The benzoic acid derivatives selectively targeted the tumour cells with high potency and efficacy. The derivatives induced the uncoupling of the oxidative phosphorylation system, decreased the transmembrane potential, and reduced ATP levels while increasing AMPK activation, thereby triggering tumour cell apoptosis in both tumour cell lines tested.

CONCLUSION

The benzoic acid derivatives studied here are promising candidates for assessing in vivo models of CRC, despite the diverse metabolic characteristics of these tumour cells.

Validation of an HPLC Method for the Simultaneous Quantification of Metabolic Reaction Products Catalysed by CYP2E1 Enzyme Activity: Inhibitory Effect of Cytochrome P450 Enzyme CYP2E1 by Salicylic Acid in Rat Liver Microsomes

Inhibition of cytochrome P450 (CYP) alters the pharmacokinetic parameters of the drug and causes drug–drug interactions. Salicylic acid been used for the treatment of colorectal cancer (CRC) and chemoprevention in recent decades. Thus, the aim of this study was to examine the in vitro inhibitory effect of salicylic acid on CYP2E1 activity in rat liver microsomes (RLMs) using high-performance liquid chromatography (HPLC). High-performance liquid chromatography analysis of a CYP2E1 assay was developed on a reversed phase C₁₈ column (SUPELCO 25 cm × 4.6 mm × 5 µm) at 282 nm using 60% H₂O, 25% acetonitrile, and 15% methanol as mobile phase. The CYP2E1 assay showed a good linearity (R² > 0.999), good reproducibility, intra- and inter-day precision (<15%), acceptable recovery and accuracy (80–120%), and low detection (4.972 µM and 1.997 µM) and quantitation limit values (15.068 µM and 6.052 µM), for chlorzoxazone and 6-hydroxychlorzoxazone, respectively. Salicylic acid acts as a mixed inhibitor (competitive and non-competitive inhibition), with K_i (inhibition constant) = 83.56 ± 2.730 µM and concentration of inhibitor causing 50% inhibition of original enzyme activity (IC₅₀) exceeding 100 µM (IC₅₀ = 167.12 ± 5.460 µM) for CYP2E1 enzyme activity. Salicylic acid in rats would have both low and high potential to cause toxicity and drug interactions with other drugs that are substrates for CYP2E1.

Compound C enhances the anticancer effect of aspirin in HER-2-positive breast cancer by regulating lipid metabolism in an AMPK-independent pathway

Various clinical studies have determined that aspirin shows anticancer effects in many human malignant cancers, including human epidermal growth factor receptor-2 (HER-2)-positive breast cancer. However, the anti-tumor mechanism of aspirin has not been fully defined. The aim of this study was to determine the role of Compound C in enhancing the anticancer effect of aspirin. HER-2-positive breast cancer cell lines were treated with aspirin with or without Compound C pre-treatment; their phenotypes and mechanisms were then analyzed in vitro and in vivo. Aspirin exhibited anticancer effects in HER-2-positive breast cancer by inhibiting cell growth and inducing apoptosis through the activation of AMP-activated protein kinase (AMPK). Unexpectedly, pre-treatment with Compound C, a widely used AMPK inhibitor, induced robust anticancer effects in cells compared to aspirin monotherapy. This anticancer effect was not distinct in HER-2 negative breast cancer MDA-MB-231 cells and may be due to the inhibition of lipid metabolism mediated by c-myc. Besides, c-myc re-expression or palmitic acid supply could partially restored cell proliferation. Aspirin exhibits anticancer effects in HER-2-positive breast cancer by regulating lipid metabolism mediated by c-myc, and Compound C strengthens these effects in an AMPK-independent manner. Our results potentially provide a novel therapeutic strategy exploiting combined aspirin and Compound C therapy for HER-2-positive breast cancer, which acts by reducing de novo lipid synthesis.

A review on gentisic acid as a plant derived phenolic acid and metabolite of aspirin: Comprehensive pharmacology, toxicology, and some pharmaceutical aspects

Beneficial therapeutic effects of phenolic acids have been proven in various research projects including in vivo and in vitro studies. Gentisic acid (GA) is a phenolic acid that has been associated with useful effects on human health, such as antiinflammatory, antigenotoxic, hepatoprotective, neuroprotective, antimicrobial, and especially antioxidant activities. It is an important metabolite of aspirin and also widely distributed in plants as a secondary plant product such as Gentiana spp., Citrus spp., Vitis vinifera, Pterocarpus santalinus, Helianthus tuberosus, Hibiscus rosa-sinensis, Olea europaea, and Sesamum indicum and in fruits such as avocados, batoko plum, kiwi fruits, apple, bitter melon, black berries, pears, and some mushrooms. This study was undertaken to review the pharmacological effects, pharmacokinetic properties as well as toxicity and pharmaceutical applications of GA.

Evidence That Calebin A, a Component of Curcuma Longa Suppresses NF-B Mediated Proliferation, Invasion and Metastasis of Human Colorectal Cancer Induced by TNF-β (Lymphotoxin)

Objective: Natural polyphenol Calebin A has been recently discovered as a novel derivate from turmeric with anti-cancer potential. Pro-inflammatory cytokine TNF-β (lymphotoxin α) is a stimulant for cancer cell malignity via activation of NF-κB pathway, also in colorectal cancer (CRC). Here, we investigated the potential of Calebin A to suppress TNF-β-induced NF-κB signalling in CRC. Materials and Methods: Three distinct CRC cell lines (HCT116, RKO, SW480) were treated in monolayer or 3-dimensional alginate culture with TNF-β, Calebin A, curcumin, BMS-345541, dithiothreitol (DTT) or antisense oligonucleotides-(ASO) against NF-κB. Results: Calebin A suppressed dose-dependent TNF-β-induced CRC cell vitality and proliferation in monolayer culture. Further, in alginate culture, Calebin A significantly suppressed TNF-β-enhanced colonosphere development, as well as invasion and colony formation of all three CRC cell lines investigated. Calebin A specifically blocked TNF-β-induced activation and nuclear translocation of p65-NF-κB, similar to curcumin (natural NF-κB inhibitor), BMS-345541 (specific IKK inhibitor) and ASO-NF-κB. Moreover, Immunofluorescence and Immunoblotting showed that Calebin A, similar to curcumin or BMS-345541 suppressed TNF-β-induced activation and nuclear translocation of p65-NF-κB and the transcription of NF-κB-promoted biomarkers associated with proliferation, migration and apoptosis, in a dose- and time-dependent manner. Those findings were potentiated by the specific treatment of extracted nuclei with DTT, which abrogated Calebin A-mediated nuclear p65-NF-κB-inhibition and restored p65-NF-κB-activity in the nucleus. Conclusion: Overall, these results demonstrate, for the first time, that multitargeted Calebin A has an anti-cancer capability on TNF-β-induced malignities through inhibitory targeting of NF-κB activation in the cytoplasm, as well as by suppressing the binding of p65-NF-κB to DNA.

Aspirin metabolites 2,3‑DHBA and 2,5‑DHBA inhibit cancer cell growth: Implications in colorectal cancer prevention

Although compelling evidence exists on the ability of aspirin to treat colorectal cancer (CRC), and numerous theories and targets have been proposed, a consensus has not been reached regarding its mechanism of action. In this regard, a relatively unexplored area is the role played by aspirin metabolites 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-dihydroxybenzoic acid (2,5-DHBA) in its chemopreventive actions. In a previous study, we demonstrated that 2,3-DHBA and 2,5-DHBA inhibited CDK1 enzyme activity in vitro. The aim of the present study was to understand the effect of these metabolites on the enzyme activity of all CDKs involved in cell cycle regulation (CDKs 1, 2, 4 and 6) as well as their effect on clonal formation in three different cancer cell lines. Additionally, in silico studies were performed to determine the potential sites of interactions of 2,3-DHBA and 2,5-DHBA with CDKs. We demonstrated that 2,3-DHBA and 2,5-DHBA inhibits CDK-1 enzyme activity beginning at 500 µM, while CDK2 and CDK4 activity was inhibited only at higher concentrations (>750 µM). 2,3-DHBA inhibited CDK6 enzyme activity from 250 µM, while 2,5-DHBA inhibited its activity >750 µM. Colony formation assays showed that 2,5-DHBA was highly effective in inhibiting clonal formation in HCT-116 and HT-29 CRC cell lines (250–500 µM), and in the MDA-MB-231 breast cancer cell line (~100 µM). In contrast 2,3-DHBA was effective only in MDA-MB-231 cells (~500 µM). Both aspirin and salicylic acid failed to inhibit all four CDKs and colony formation. Based on the present results, it is suggested that 2,3-DHBA and 2,5-DHBA may contribute to the chemopreventive properties of aspirin, possibly through the inhibition of CDKs. The present data and the proposed mechanisms should open new areas for future investigations.

Tomato glycosyltransferase Twi1 plays a role in flavonoid glycosylation and defence against virus

BACKGROUND

Secondary metabolites play an important role in the plant defensive response. They are produced as a defence mechanism against biotic stress by providing plants with antimicrobial and antioxidant weapons. In higher plants, the majority of secondary metabolites accumulate as glycoconjugates. Glycosylation is one of the commonest modifications of secondary metabolites, and is carried out by enzymes called glycosyltransferases.

RESULTS

Here we provide evidence that the previously described tomato wound and pathogen-induced glycosyltransferase Twi1 displays in vitro activity toward the coumarins scopoletin, umbelliferone and esculetin, and the flavonoids quercetin and kaempferol, by uncovering a new role of this gene in plant glycosylation. To test its activity in vivo, Twi1-silenced transgenic tomato plants were generated and infected with Tomato spotted wilt virus. The Twi1-silenced plants showed a differential accumulation of Twi1 substrates and enhanced susceptibility to the virus.

CONCLUSIONS

Biochemical in vitro assays and transgenic plants generation proved to be useful strategies to assign a role of tomato Twi1 in the plant defence response. Twi1 glycosyltransferase showed to regulate quercetin and kaempferol levels in tomato plants, affecting plant resistance to viral infection.

The Flavonoid Metabolite 2,4,6-Trihydroxybenzoic Acid Is a CDK Inhibitor and an Anti-Proliferative Agent: A Potential Role in Cancer Prevention

Flavonoids have emerged as promising compounds capable of preventing colorectal cancer (CRC) due to their anti-oxidant and anti-inflammatory properties. It is hypothesized that the metabolites of flavonoids are primarily responsible for the observed anti-cancer effects owing to the unstable nature of the parent compounds and their degradation by colonic microflora. In this study, we investigated the ability of one metabolite, 2,4,6-trihydroxybenzoic acid (2,4,6-THBA) to inhibit Cyclin Dependent Kinase (CDK) activity and cancer cell proliferation. Using in vitro kinase assays, we demonstrated that 2,4,6-THBA dose-dependently inhibited CDKs 1, 2 and 4 and in silico studies identified key amino acids involved in these interactions. Interestingly, no significant CDK inhibition was observed with the structurally related compounds 3,4,5-trihydroxybenzoic acid (3,4,5-THBA) and phloroglucinol, suggesting that orientation of the functional groups and specific amino acid interactions may play a role in inhibition. We showed that cellular uptake of 2,4,6-THBA required the expression of functional SLC5A8, a monocarboxylic acid transporter. Consistent with this, in cells expressing functional SLC5A8, 2,4,6-THBA induced CDK inhibitory proteins p21^Cip1 and p27^Kip1 and inhibited cell proliferation. These findings, for the first time, suggest that the flavonoid metabolite 2,4,6-THBA may mediate its effects through a CDK- and SLC5A8-dependent pathway contributing to the prevention of CRC.

Anti-Inflammatory Effects of Pomegranate Peel Extracts on In Vitro Human Intestinal Caco-2 Cells and Ex Vivo Porcine Colonic Tissue Explants

The aim of this study was to determine the anti-inflammatory potential of pomegranate peel extracts (PPE) prepared from waste material of pomegranate juice production both in vitro on Caco-2 cells and ex vivo using porcine colonic tissue explants. Caco-2 cells were stimulated in vitro by TNF and colonic tissue explants were stimulated ex vivo with lipopolysaccharide (LPS). Both tissues were co-treated with PPE at 0, 1.0, 2.5, 5.0, 10 and 25 μg/mL. The secretion of CXCL8 in the supernatant of both experiments was determined by enzyme linked immunosorbent assay (ELISA) and the relative expression of inflammatory cytokines were evaluated in the colonic tissue by quantitative polymerase chain reaction (QPCR). The 2.5 to 25 μg/mL of PPE suppressed CXCL8 (p < 0.001) in the Caco-2 cells, whereas CXCL8 production was suppressed by only 5 and 25 μg/mL (p < 0.01) of PPE in the colonic explants. The 5 μg/mL of PPE also suppressed the expression of IL1A (p < 0.05), IL6 (p < 0.01) and CXCL8 (p < 0.05) in LPS challenged colonic tissues compared to controls. In conclusion, the 5 μg/mL of PPE consistently elicits strong anti-inflammatory activity. These results support the potential of bioactive compounds from the waste peel of pomegranate in terms of their anti-inflammatory activity in cells and tissues of the gastrointestinal tract.

Complex roles of the old drug aspirin in cancer chemoprevention and therapy

The nonsteroidal anti-inflammatory agent aspirin is widely used for preventing and treating cardiovascular and cerebrovascular diseases. In addition, epidemiologic evidences reveal that aspirin may prevent a variety of human cancers, while data on the association between aspirin and some kinds of cancer are conflicting. Preclinical studies and clinical trials also reveal the therapeutic effect of aspirin on cancer. Although cyclooxygenase is a well-known target of aspirin, recent studies uncover other targets of aspirin and its metabolites, such as AMP-activated protein kinase, cyclin-dependent kinase, heparanase, and histone. Accumulating evidence demonstrate that aspirin may act in different cell types, such as epithelial cell, tumor cell, endothelial cell, platelet, and immune cell. Therefore, aspirin acts on diverse hallmarks of cancer, such as sustained tumor growth, metastasis, angiogenesis, inflammation, and immune evasion. In this review, we focus on recent progress in the use of aspirin for cancer chemoprevention and therapy, and integratively analyze the mechanisms underlying the anticancer effects of aspirin and its metabolites. We also discuss mechanisms of aspirin resistance and describe some derivatives of aspirin, which aim to overcome the adverse effects of aspirin.

Platelet Metabolism and Other Targeted Drugs; Potential Impact on Immunotherapy

The role of platelets in cancer progression has been well recognized in the field of cancer biology. Emerging studies are elaborating further the additional roles and added extent that platelets play in promoting tumorigenesis. Platelets release factors that support tumor growth and also form heterotypic aggregates with tumor cells, which can provide an immune-evasive advantage. Their most critical role may be the inhibition of immune cell function that can negatively impact the body’s ability in preventing tumor establishment and growth. This review summarizes the importance of platelets in tumor progression, therapeutic response, survival, and finally the notion of immunotherapy modulation being likely to benefit from the inclusion of platelet inhibitors.