The immunoregulatory function of polyphenols: implications in cancer immunity

New Therapeutic Strategies for Obesity and Its Metabolic Sequelae: Brazilian Cerrado as a Unique Biome

Brazil has several important biomes holding impressive fauna and flora biodiversity. Cerrado being one of the richest ones and a significant area in the search for new plant-based products, such as foods, cosmetics, and medicines. The therapeutic potential of Cerrado plants has been described by several studies associating ethnopharmacological knowledge with phytochemical compounds and therapeutic effects. Based on this wide range of options, the Brazilian population has been using these medicinal plants (MP) for centuries for the treatment of various health conditions. Among these, we highlight metabolic diseases, namely obesity and its metabolic alterations from metabolic syndrome to later stages such as type 2 diabetes (T2D). Several studies have shown that adipose tissue (AT) dysfunction leads to proinflammatory cytokine secretion and impaired free fatty acid (FFA) oxidation and oxidative status, creating the basis for insulin resistance and glucose dysmetabolism. In this scenario, the great Brazilian biodiversity and a wide variety of phytochemical compounds make it an important candidate for the identification of pharmacological strategies for the treatment of these conditions. This review aimed to analyze and summarize the current literature on plants from the Brazilian Cerrado that have therapeutic activity against obesity and its metabolic conditions, reducing inflammation and oxidative stress.

Acer truncatum leaves extract modulates gut microbiota, improves antioxidant capacity, and alleviates lipopolysaccharide-induced inflammation in broilers

This study investigated the appropriate way of dietary Acer truncatum leaves (ATL) addition, the effect of disease prevention and its mechanism of action. In experiment 1, 192 Arbor Acres broilers were assigned to 4 treatment groups, fed with basal diets containing 2% bran, replacing it with primary and fermented ATL, and additional 0.3% ATL extract to the basal diet for 42 d, respectively. In experiment 2, 144 broilers were assigned to 3 treatment groups for 21-d trial: (1) C-N group, basal diets, and injected with 0.9% (w/v) sterile saline; (2) C-L group, basal diets, and injected with lipopolysaccharide (LPS); (3) T-L group, ATL diets and injected with LPS. In experiment 1, ATL significantly decreased the index of abdominal fat at 42 d (P < 0.05). ATL extract had a better ability to improve antioxidant capacity and reduce inflammatory levels among all treatment groups, which significantly decreased the content of MDA in the liver and ileum mucosa at 21 d, and increased the expression of IL-10 and Occludin in jejunal mucosa at 42 d (P < 0.05). In experiment 2, ATL significantly increased the level of T-AOC in the liver, decreased the expression of NF-κB in the jejunal mucosa and ileum mucosa (P < 0.05), and restored LPS-induced the changed level of CAT in jejunal mucosa, the expression of IL-6, Claudin-1, and ZO-1 in jejunal mucosa and IL-1β in ileum mucosa (P < 0.05). Analysis of gut microbiota indicated that ATL enhanced the abundances of Bacteroidota and reduced the proportion of Firmicutes (P < 0.05), and the changed levels of T-AOC in body, IL-1β, IL-6, IL-10, and NF-κB in jejunum mucosa and propionic acid in cecal were associated with gut microbiota. Collectively, our data showed that the extract of ATL had a better antioxidant and anti-inflammatory effects than primality and fermented. Extraction of ATL modulated intestinal microbiota, and had a protective effect on oxidative stress, inflammation, and intestinal barrier function in broilers challenged with LPS.

Acrocomia aculeata associated with doxorubicin: cardioprotection and anticancer activity

Doxorubicin (Dox) is a chemotherapeutic agent widely used in the clinic, whose side effects include cardiotoxicity, associated with decreased antioxidant defenses and increased oxidative stress. The association of Dox with natural antioxidants can extend its use if not interfering with its pharmacological potential. In this study, we aimed to understand the effects and mechanisms of the aqueous extract of Acrocomia aculeata leaves (EA-Aa) in cancer cells and the co-treatment with Dox, in in vitro and in vivo models. It was found that EA-Aa showed a relevant decrease in the viability of cancer cells (K562 and MCF-7) and increased apoptosis and death. The Dox cytotoxic effect in co-treatment with EA-Aa was increased in cancer cells. The therapeutic association also promoted a change in cell death, leading to a higher rate of apoptosis compared to the Dox group, which induced necrosis. In addition, in non-cancer cells, EA-Aa enhanced red blood cell (RBC) redox state with lower hemolysis and malondialdehyde (MDA) content and had no in vitro nor in vivo toxicity. Furthermore, EA-Aa showed antioxidant protection against Dox-induced cytotoxicity in H9c2 cells (cardiomyoblast), partially mediated by the NRF2 pathway. In vivo, EA-Aa treatment showed a relevant decrease in MDA levels in the heart, kidney, and brain, evaluated in C57Bl/6 mice induced to cardiotoxicity by Dox. Together, our results proved the effectiveness of EA-Aa in potentiating Dox anticancer effects, with antioxidant and cardioprotective activity, suggesting EA-Aa as a potential Dox pharmacological adjuvant.

Recent Developments in Polyphenol Applications on Human Health: A Review with Current Knowledge

Polyphenol has been used in treatment for some health disorders due to their diverse health promoting properties. These compounds can reduce the impacts of oxidation on the human body, prevent the organs and cell structure against deterioration and protect their functional integrity. The health promoting abilities are attributed to their high bioactivity imparting them high antioxidative, antihypertensive, immunomodulatory, antimicrobial, and antiviral activity, as well as anticancer properties. The application of polyphenols such as flavonoids, catechin, tannins, and phenolic acids in the food industry as bio-preservative substances for foods and beverages can exert a superb activity on the inhibition of oxidative stress via different types of mechanisms. In this review, the detailed classification of polyphenolic compunds and their important bioactivity with special focus on human health are addressed. Additionally, their ability to inhibit SARS-CoV-2 could be used as alternative therapy to treat COVID patients. Inclusions of polyphenolic compounds in various foods have demonstrated their ability to extend shelf life and they positive impacts on human health (antioxidative, antihypertensive, immunomodulatory, antimicrobial, anticancer). Additionally, their ability to inhibit the SARS-CoV-2 virus has been reported. Considering their natural occurrence and GRAS status they are highly recommended in food.

Facile preparation of a metal-phenolic network-based lymph node targeting nanovaccine for antitumor immunotherapy

Cancer vaccines are being explored for enhanced cancer immunotherapy and prophylaxis. Some of their prevailing weaknesses, however, such as complicated preparation, poor biocompatibility, and failure to elicit strong cellular immune responses, have limited their further clinical applications. Here, we reported a multifunctional nanovaccine that was prepared in a quick and simple way. During the self-assembly of metal-phenolic networks (MPNs), the antigen ovalbumin (OVA) and immunoreactive chlorogenic acid (CHA) were simultaneously loaded. Owing to its dual pH and reduction sensitivities, the nanovaccine could deliver antigens into the cytoplasm of dendritic cells (DCs) and facilitate the cross-presentation of antigens. Moreover, the results of in vivo immunization assays demonstrated that the nanovaccine significantly excited the antigen presentation of DCs and provoked a robust cellular immune response with the restrained activation of regulatory T cells (Tregs), by targeting lymph nodes and executing the function of CHA. In vivo antitumor assays indicated that the nanovaccine with good biocompatibility afforded conspicuous cancer treatment and prevention effects. Overall, the nanovaccine presented in this study shows a promise for potentiating cancer immunotherapy by the lymph node-targeted delivery. STATEMENT OF SIGNIFICANCE: Cancer nanovaccines can be used for cancer immunotherapy. However, some existing shortcomings, such as cumbersome preparation, poor biocompatibility, and failure to elicit strong immune responses, limit the clinical application of cancer nanovaccines. This study developed a multifunctional nanovaccine that was readily prepared through the self-assembly of metal-phenolic networks. The nanovaccine with dual pH and reduction sensitivities could efficiently promote the antigen lysosome escape and cross-presentation. In vivo, it efficiently delivered antigen into lymph nodes and provoked strong cellular immune responses, and thus it showed significant cancer immunotherapy and prevention effect.

Do ultrasonic field effects upon the polyphenolics profile of propolis extracts improve their antioxidant and antimicrobial activity?

Ultrasound-assisted extraction (UAE) was applied for polyphenols extraction from Romanian propolis, followed by comparison with previous maceration work. The effects consisted not only in time reduction and extraction yield increase, but also in polyphenolics profile modification in terms of flavonoids / polyphenolic acids ratio. The operating parameters were ultrasounds (US) field exposure time (10-100 min), solvent composition (water, 25 % and 50 % ethanolic solutions, w/w), and liquid:solid ratio (2:1, 4:1 and 6:1, w:w), while keeping temperature constant. 24 polyphenolic derivatives were quantified by UHPLC-HRMS. UAE favored the extraction of pinocembrin, isorhamnetin and chrysin in water and 25 % ethanol, leading to different profiles than maceration, and further influences upon the antioxidant and antimicrobial activity. All extracts demonstrated increased antibacterial and antifungal activity compared to maceration, particularly the 50 % ethanolic extracts, which presented a three-times larger antioxidant capacity. Chemometric methods (Principal Component Analysis - PCA and Partial Least Squares Regression - PLS) and a saturation type model were used to correlate the polyphenolics profiles and antioxidant capacity. Experimental and modelling results concluded that 50 % ethanolic solutions and UAE represent the favorable operating conditions in terms of yield and extracts quality.

Phellinus baumii Polyphenol: A Potential Therapeutic Candidate against Lung Cancer Cells

Phellinus baumii, a fungus that grows on mulberry trees and is used in traditional Chinese medicine, exerts therapeutic effects against various diseases, including cancer. Polyphenols, generally considered to be antioxidants, have antitumor and proapoptotic effects. In this study, we identified the composition of Phellinus baumii polyphenol (PBP) and characterized its 17 chemical components by UPLC-ESI-QTOF-MS. Furthermore, to clarify the potential mechanism of PBP against Lung Cancer Cells, network pharmacology and experimental verification were combined. Molecular docking elucidated the binding conformation and mechanism of the primary active components (Osmundacetone and hispidin) to the core targets CASP3, PARP1 and TP53. In addition, potential molecular mechanisms of PBP predicted by network pharmacology analysis were validated in vitro. PBP significantly inhibited the human lung cancer A549 cells and showed typical apoptotic characteristics, without significant cytotoxicity to normal human embryonic kidney (HEK293) cells. Analysis using flow cytometry and western blot indicated that PBP caused apoptosis, cell cycle arrest, reactive oxygen species (ROS) accumulation, and mitochondrial membrane potential (MMP) depression in A549 cells to exercise its antitumor effects. These results reveal that PBP has great potential for use as an active ingredient for antitumor therapy.

Extraction and characterization of phenolic compounds with antioxidant and antimicrobial activity from avocado seed (Persea americana mill)

The increase in the demand for Hass avocado has brought a rise in the generation of inedible waste such as peel and seed, by-products that are rich in bioactive substances. In the present study, aqueous, ethanolic, and supercritical fluid extracts were obtained from fresh seed and dry seed, which were analyzed to determine the antioxidant capacity measured through 2,2-diphenyl-2-picrylhydrazyl free radical (DPPH); 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) methods as well as the content of phenolic compounds. In addition, the antimicrobial activity of strains of food interest, such as Listeria monocytogenes, Salmonella enterica Typhimurium and Escherichia coli was evaluated. The ethanolic extract of fresh seed presented the highest antioxidant and antimicrobial activity. The aqueous extract of fresh seed registered a significant antioxidant capacity but an absence of antimicrobial activity. In contrast, the ethanolic extract of dry seed showed a representative antimicrobial activity on both S. enterica Typhimurium and L. monocytogenes, but low antioxidant activity. E. coli exhibited resistance against all the assessed extracts. The results from this work highlight the opportunity to consider the Hass avocado seed extracts as a novel alternative to replace or reduce the use of synthetic antioxidant and antimicrobial additives in food. Keywords: Waste by-product; Aqueous extract; Ethanolic extract; Supercritical extraction; Polyphenols; Free radical.

LncRNA-mediated ceRNA regulatory network provides new insight into chlorogenic acid synthesis in sweet potato

Sweet potato (Ipomoea batatas L.) is considered a highly nutritional and economical crop due to its high contents of bioactive substances, such as anthocyanin and chlorogenic acid (CGA), especially in leaves and stems. The roles of noncoding RNAs (ncRNA), including long noncoding RNA (lncRNA) and microRNA (miRNA), in CGA synthesis, are still unknown. In this study, the differentially expressed (DE) mRNAs, miRNAs, and lncRNAs in two leafy vegetable genotypes "FS7-6-14-7" (high CGA content) and "FS7-6" (low CGA content) were identified. The cis-regulation between lncRNA and mRNA was analyzed. Then, the CGA synthesis-related modules MEBlue and MEYellow were identified to detect trans-regulation mRNA-lncRNA pairs. The GO and KEGG annotations suggested that mRNA in these two modules was significantly enriched in the secondary metabolite synthesis biosynthesis category. A competing endogenous RNAs (ceRNA) network, including 8730 miRNA-mRNA and 444 miRNA-lncRNA pairs, was constructed by DEmiRNA target prediction. Then, a CGA synthesis-related ceRNA network was obtained with lncRNA and mRNA from MEBlue and MEYellow. Finally, one relational pair, MSTRG.47662.1/mes-miR398/itb04g00990, was selected for functional validation. Overexpression of lncRNA MSTRG.47662.1 and mRNA itb04g00990 increased CGA content in both tobacco and sweet potato callus, while overexpression of miRNA mes-miR398 decreased CGA content. Meanwhile, regression analysis of the expression patterns demonstrated that MSTRG.47662.1, acting as a ceRNA, promoted itb04g00990 expression by competitively binding mes-miR398 in CGA synthesis in sweet potato. Our results provide insights into how ncRNA-mediated ceRNA regulatory networks likely contribute to CGA synthesis in leafy sweet potato.

Polyphenols: Chemoprevention and therapeutic potentials in hematological malignancies

Polyphenols are one of the largest plant-derived natural product and they play an important role in plants' defense as well as in human health and disease. A number of them are pleiotropic molecules and have been shown to regulate signaling pathways, immune response and cell growth and proliferation which all play a role in cancer development. Hematological malignancies on the other hand, are cancers of the blood. While current therapies are efficacious, they are usually expensive and with unwanted side effects. Thus, the search for newer less toxic agents. Polyphenols have been reported to possess antineoplastic properties which include cell cycle arrest, and apoptosis via multiple mechanisms. They also have immunomodulatory activities where they enhance T cell activation and suppress regulatory T cells. They carry out these actions through such pathways as PI3K/Akt/mTOR and the kynurenine. They can also reverse cancer resistance to chemotherapy agents. In this review, i look at some of the molecular mechanism of action of polyphenols and their potential roles as therapeutic agents in hematological malignancies. Here i discuss their anti-proliferative and anti-neoplastic activities especially their abilities modulate signaling pathways as well as immune response in hematological malignancies. I also looked at clinical studies done mainly in the last 10-15 years on various polyphenol combination and how they enhance synergism. I recommend that further preclinical and clinical studies be carried out to ensure safety and efficacy before polyphenol therapies be officially moved to the clinics.

Phytochemical Screening and Antioxidant Activity of Seven Native Species Growing in the Forests of Southern Chilean Patagonia

The genus Nothofagus is one of the most abundant in the subantarctic Patagonian forests. Five species inhabit these ecosystems, three evergreen (Nothofagus betuloides, Nothofagus dombeyi, and Nothofagus nitida) and two deciduous (Nothofagus pumilio and Nothofagus antarctica). This is the first report on the levels of secondary metabolites and the antioxidant capacity of Patagonian tree species growing in natural environments. The aim of this work was to carry out a phytochemical screening, to determine the antioxidant capacity, the sun protection factor, and the α-glucosidase and tyrosinase inhibitory activity of foliar extracts of the five previous species. Besides, Aristotelia chilensis and Berberis microphylla, two species of Patagonian shrubs growing in the same forests, were used as reference. N. dombeyi was the Nothofagus with the best antioxidant capacity. B. microphylla differed from all studied species. Moreover, the Nothofagus was split into two groups. N. betuloides and N. dombeyi are the most similar species to A. chilensis. The α-glucosidase was completely inhibited by all studied extracts. Furthermore, N. antarctica, N.pumilio, and N. nitida inhibited about 70% of the tyrosinase activity. All the results found in this study for the species of the genus Nothofagus support further research on their potential beneficial properties for human health.

Integrated transcriptome, small RNA and degradome sequencing approaches proffer insights into chlorogenic acid biosynthesis in leafy sweet potato

Leafy sweet potato is rich in total phenolics (TP) which play key roles in health protection, the chlorogenic acid (CGA) constitutes the major components of phenolic compounds in leafy sweet potato. Unfortunately, the mechanism of CGA biosynthesis in leafy sweet potato is unclear. To dissect the mechanisms of CGA biosynthesis, we performed transcriptome, small RNA (sRNA) and degradome sequencing of one low-CGA content and one high-CGA content genotype at two stages. A total of 2,333 common differentially expressed genes (DEGs) were identified, and the enriched DEGs were related to photosynthesis, starch and sucrose metabolism and phenylpropanoid biosynthesis. The functional genes, such as CCR, CCoAOMT and HCT in the CGA biosynthetic pathway were down-regulated, indicating that the way to lignin was altered, and two possible CGA biosynthetic routes were hypothesized. A total of 38 DE miRNAs were identified, and 1,799 targets were predicated for 38 DE miRNAs by using in silico approaches. The target genes were enriched in lignin and phenylpropanoid catabolic processes. Transcription factors (TFs) such as apetala2/ethylene response factor (AP2/ERF) and Squamosa promoter binding protein-like (SPL) predicated in silico were validated by degradome sequencing. Association analysis of the DE miRNAs and transcriptome datasets identified that miR156 family negatively targeted AP2/ERF and SPL. Six mRNAs and six miRNAs were validated by qRT-PCR, and the results showed that the expression levels of the mRNAs and miRNAs were consistent with the sequencing data. This study established comprehensive functional genomic resources for the CGA biosynthesis, and provided insights into the molecular mechanisms involving in this process. The results also enabled the first perceptions of the regulatory roles of mRNAs and miRNAs, and offered candidate genes for leafy sweet potato improvements.