Co-Adjuvant Therapy Efficacy of Catechin and Procyanidin B2 with Docetaxel on Hormone-Related Cancers In Vitro

Exploring the Synergistic Effect of Sildenafil and Green Tea Polyphenols on Breast Cancer Stem Cell-like Cells and their Parental Cells: A Potential Novel Therapeutic Approach

BACKGROUND

Many cancer studies have intensely focused on the role of diet, among other factors involved in cancer establishment. The positive effect of green tea polyphenols (GTP) on controlling breast cancer cells has been reported in several studies. Cancer stem cell-like cells (CSC-LCs) possessing self-renewal, metastatic, and drug-resistant capacities are considered prominent therapeutic targets. In many tumors, inducible nitric oxide synthase (iNOS) expression levels are high; however, they have a dual effect on breast cancer pathogenesis.

OBJECTIVE

This study aimed to investigate the cytotoxicity of the iNOS agonist (Sildenafil) and antagonist (LNAME), both alone and in combination with GTP, on MDA-MB-231, CD44+/CD24- CSC-LCs, and their parental cells (MCF-7).

METHODS

The cell viability assay has been studied using the MTT assay. To analyze drug-drug combinations, CompuSyn and Combenefit software were used. The cytotoxicity mechanism was determined using flow cytometric analysis.

RESULTS

L-NAME and GTP showed a synergistic effect on MDA-MB-231 and CSC-LCs. Such an effect was not observed on MCF-7. Sildenafil and GTP, on the other hand, showed synergistic cytotoxicity in all the cells mentioned above. Flow cytometric tests resulted in more than 70% apoptosis in MDA-MB-231 and MCF-7. Also, sub-G1 arrest among MCF-7 cells and a considerable decrease in ROS production by MDA-MB-231 cells following treatment with Sildenafil and GTP were observed.

CONCLUSION

Sildenafil, in combination with flavonoids, may be considered a novel strategy for cancer treatment.

Exploring the Remarkable Chemotherapeutic Potential of Polyphenolic Antioxidants in Battling Various Forms of Cancer

Plant-derived compounds, specifically antioxidants, have played an important role in scavenging the free radicals present under diseased conditions. The persistent generation of free radicals in the body leads to inflammation and can result in even more severe diseases such as cancer. Notably, the antioxidant potential of various plant-derived compounds prevents and deregulates the formation of radicals by initiating their decomposition. There is a vast literature demonstrating antioxidant compounds' anti-inflammatory, anti-diabetic, and anti-cancer potential. This review describes the molecular mechanism of various flavonoids, such as quercetin, kaempferol, naringenin, epicatechin, and epicatechin gallate, against different cancers. Additionally, the pharmaceutical application of these flavonoids against different cancers using nanotechnologies such as polymeric, lipid-based nanoparticles (solid-lipid and liquid-lipid), liposomes, and metallic nanocarriers is addressed. Finally, combination therapies in which these flavonoids are employed along with other anti-cancer agents are described, indicating the effective therapies for the management of various malignancies.

Anticarcinogenic potentials of tea catechins

Catechins are a cluster of polyphenolic bioactive components in green tea. Anticarcinogenic effects of tea catechins have been reported since the 1980s, but it has been controversial. The present paper reviews the advances in studies on the anticarcinogenic activities of tea and catechins, including epidemiological evidence and anticarcinogenic mechanism. Tea catechins showed antagonistic effects on many cancers, such as gynecological cancers, digestive tract cancers, incident glioma, liver and gallbladder cancers, lung cancer, etc. The mechanism underlying the anticarcinogenic effects of catechins involves in inhibiting the proliferation and growth of cancer cells, scavenging free radicals, suppressing metastasis of cancer cells, improving immunity, interacting with other anticancer drugs, and regulating signaling pathways. The inconsistent results and their causes are also discussed in this paper.

Phytochemical Profile and Antioxidant, Antiproliferative, and Antimicrobial Properties of Rubus idaeus Seed Powder

In the context of the contemporary research on sustainable development and circular economy, the quest for effective strategies aimed at revaluation of waste and by-products generated in industrial and agricultural production becomes important. In this work, an ethanolic extract from red raspberry (Rubus idaeus) seed waste (WRSP) was evaluated for its phytochemical composition and functional properties in term of antioxidative, antiproliferative, and antimicrobial activities. Chemical composition of the extract was determined by both HPLC-ESI-MS/MS and spectrophotometric methods. Phytochemical analysis revealed that flavan-3-ols and flavonols were the major phenolic compounds contained in WRSP. The extract demonstrated very high radical-scavenging (4.86 ± 0.06 µmol TE/DW) and antioxidant activity in a cell-based model (0.178 ± 0.03 mg DW/mL cell medium). The WRSP extract also exhibited antiproliferative activity against three different epithelial cancer cell lines (MCF-7, HepG2, and HeLa cells) in a dose-dependent manner. Finally, microbiological assays showed the absence of colonies of bacteria and microscopic fungi (yeasts and molds) and revealed that the WRSP extract has a large inhibition spectrum against spoilage and pathogenic bacteria, without inhibitory activity against pro-technological bacteria. In conclusion, the obtained results show that WRSP is a rich source of phytochemical compounds exerting interesting biological activities. For these reasons WRSP could find applications in the nutritional, nutraceutical, and pharmacological fields.

Polyphenol and Tannin Nutraceuticals and Their Metabolites: How the Human Gut Microbiota Influences Their Properties

Nutraceuticals have been receiving increasing attention in the last few years due to their potential role as adjuvants against non-communicable chronic diseases (cardiovascular disease, diabetes, cancer, etc.). However, a limited number of studies have been performed to evaluate the bioavailability of such compounds, and it is generally reported that a substantial elevation of their plasma concentration can only be achieved when they are consumed at pharmacological levels. Even so, positive effects have been reported associated with an average dietary consumption of several nutraceutical classes, meaning that the primary compound might not be solely responsible for all the biological effects. The in vivo activities of such biomolecules might be carried out by metabolites derived from gut microbiota fermentative transformation. This review discusses the structure and properties of phenolic nutraceuticals (i.e., polyphenols and tannins) and the putative role of the human gut microbiota in influencing the beneficial effects of such compounds.