Antioxidant and antibacterial activity of Trametes polyzona (Pers.) Justo.

Polypores are cosmopolitan mushrooms, widely investigated for their beneficial properties in combatting multidrug resistant pathogens. The present study focuses on the need for new, naturally sourced antimicrobial and antioxidant compounds from mushrooms. The antioxidant and antibacterial activity of the phenolic extract of strains of Trametes polyzona (Pers.) Justo, were investigated. Strains of T. polyzona were analyzed for total phenolic content, Trolox antioxidant equivalent, DPPH radical scavenging and antibacterial activities. The amplification of the ribosomal DNA-ITS fragments from DNA of selected mushrooms was carried out using ITS1 and ITS4 primers. The antibacterial activity of phenolic extracts of T. polyzona was comparable to the antibiotics, ceftazidime and erythromycin. T. polyzona extracts inhibited the growth of the different strains of K. pneumoniae, E. coli, S. aureus, and S. enterica tested in this study. The results of the study demonstrate that, T. polyzona can be a potential source of antimicrobial and antioxidant compounds.

Peanut protein-polyphenol aggregate complexation suppresses allergic sensitization to peanut by reducing peanut-specific IgE in C3H/HeJ mice.

Peanut allergy is usually lifelong and accidental exposure impose formidable risk. The aim of this study was to assess the capacity of peanut proteins complexed to polyphenol extracts to reduce allergic response in C3H/HeJ mice. Mice were sensitized to peanut flour followed by exposure to amino acid diets fortified with peanut protein-polyphenol aggregates of either with low (15%; w/w) or high (40%; w/w) complexation ratios of blueberry (BB-Low and BB-High) and cranberry (CB-Low and CB-High) extracts. Treatment groups on diets with high complexation ratios of blueberry and cranberry aggregates showed significant reduction in peanut specific plasma Immunoglobulin E (IgE). Western blot analysis of spleen lysates showed CD63 protein expression was reduced in a dose-dependent manner in blueberry and cranberry complexed peanut protein supplemented diet groups. Our results demonstrate for the first time that complexation of polyphenols to peanut flour can potentially lower plasma IgE of peanut-sensitized C3H/HeJ mice.

Peanut flour aggregation with polyphenolic extracts derived from peanut skin inhibits IgE binding capacity and attenuates RBL-2H3 cells degranulation via MAPK signaling pathway.

This study investigates the anti-allergic properties of peanut skin polyphenols (PSP)-enriched peanut (PN) protein aggregates. PSP was blended with PN flour at concentrations of 5, 10, 15, 30, and 40% (w/w). Rat basophil leukemia cells (RBL-2H3) were sensitized with either anti-DNP-IgE or PN-allergic plasma followed by co-exposure to unmodified PN flour (control) or PSP-PN protein aggregates and Ca2+ ionophore, ionomycin. Immunoblotting and staining were performed to measure the IgE binding capacity of PSP-PN aggregates. Results showed that 30% PSP-PN aggregate significantly reduced ß-hexosaminidase and histamine levels by 54.2% and 49.2%, respectively compared with control. Immunoblotting results revealed 40% PSP-PN aggregates significantly decreased IgE binding by 19%. The phosphorylation of p44/42 MAPK was significantly reduced while phosphorylation of p38 MAPK and SAPK/JNK increased upon PSP-PN protein aggregate exposure to the cells. Our results show that aggregation of PSP to PN proteins reduces allergic response by inhibiting Ca2+-induced MAPK-dependent cell degranulation.

Bioavailability and hypolipidemic effects of peanut skin polyphenols.

Peanut skin is a rich source of polyphenols, such as proanthocyanidins. Peanut skin proanthocyanidins mainly consist of a subgroup called procyanidins. Peanut-based procyanidins contain oligomers of both type A and type B procyanidins. Recent studies have shown that peanut skin extracts exert protection against hepatic steatosis induced on rats fed with a high-fat diet. Studies have shown that proanthocyanidins protect against cardiovascular diseases (CVDs). The mechanism of CVD protection and hypolipidemic effect of peanut skin procyanidins has been gradually revealed in recent years. Due to the high molecular weight of procyanidins, they are not readily absorbed through the gut barrier. It is hypothesized that procyanidins exert their effect by inhibiting the absorption of dietary lipid and chylomicron secretion by enterocytes. In this review, we aim to highlight the hypolipidemic effects of peanut skin polyphenols and discuss the various molecular mechanisms, with which the polyphenols may exert the lipid-lowering function observed by weighing the absorption characteristics as well as gene expression mechanism responsible for lipid homeostasis.

Bioavailability of polyphenols from peanut skin extract associated with plasma lipid lowering function.

Peanut skin is a rich source of polyphenols including procyanidins and is shown to have hypolipidemic properties. This study investigated the bioavailability of peanut skin polyphenols using a rat model. First, the bioavailability of peanut skin polyphenols in rat plasma was evaluated. Our results showed procyanidin A2 levels in plasma peaked within 30 min of ingestion. The results of a second study show that peanut skin extract supplemented in addition to oil gavage resulted in significant decrease in plasma triglyceride and VLDL within 5h. In the third study, rats were given a Western type diet for 5 weeks with peanut skin extract at a dose of 150 and 300 mg/kg body weight. The main effects observed were lowering of total blood lipid and reduction of the plasma fatty acids profile. Our results suggest that procyanidin A may impart a key role of hypolipidemic effect seen in peanut skin polyphenols.

Cinnamon extract inhibits angiogenesis in zebrafish and human endothelial cells by suppressing VEGFR1, VEGFR2, and PKC-mediated MAP kinase.

Angiogenesis is a process of new blood vessel generation and under pathological conditions, lead to tumor development, progression, and metastasis. Many bioactive components have been studied for its antiangiogenic properties as a preventive strategy against tumor development. This study is focused on the effects of cinnamon extract in modulating the pathway involved in angiogenesis. Human umbilical vein endothelial cells (HUVEC) were treated with cinnamon extract at a concentration of 25 µg/mL for 1, 3, or 6 h followed by treatment with phorbol ester (TPA) at a concentration of 10 nmol/L to induce mitogen-activated protein kinase (MAPK) expression. Results show that cinnamon extract inhibited TPA-induced phosphorylation of MAPK and AKT in a dose-dependent manner. Gene expression results in HUVEC showed that cinnamon extract treatment inhibited TPA induction of protein kinase C, PKCα and PKCη messenger RNA (mRNA) expression in a dose-dependent manner along with suppression of vascular endothelial growth factor receptor 1 (VEGFR1/Flt1) and vascular endothelial growth factor receptor 2 (VEGFR2/KDR/Flk1) mRNA expression. Cinnamon extract was administered to zebrafish embryos during gastrulation at 6-8 h post fertilization (hpf). The embryos were observed for changes in morphology, toxicity, and blood vessel development. The intersegmental vessels in the zebrafish embryos were attenuated and underdeveloped at an effective cinnamon extract dose of 250 µg/mL compared with the DMSO-treated control. Exposure to cinnamon extract for 36 h resulted in gross morphological deformities. The results suggest the effect of cinnamon extract on angiogenesis is mediated by PKC-dependent phosphorylation of MAPK.

Evaluation of hypolipidemic effects of peanut skin-derived polyphenols in rats on Western-diet.

The effect of water soluble polyphenolic extract of peanut skin (PE) was investigated for its hypolipidemic properties in rats on Western diet. Seven-weeks old Wistar rats received control diet (AIN-93G), Western diet with and without a bolus of PE five times a week for 10weeks. Group which received 300mg/kg body weight showed significantly reduced body weight and epididymal fat. Plasma and liver triglyceride (TG) and cholesterol (TC) levels were significantly reduced while faecal secretion of TG and TC was greatly increased upon PE administration. Liver mRNA expression of enzymes involved in fatty acid synthesis, such as fatty acid synthase (FAS), sterol receptor element binding protein (SREBP)-1c, acetyl-CoA carboxylase (ACC1) and lipid uptake genes, such as PPARγ, were decreased, while PPARα was up-regulated by administration of PE. These data suggest that administration of PE may contribute to the improved lipid homoeostasis in rats on diets high in cholesterol and lipids.