Mixture Of Polyphenolic Compounds Research Articles

In Vitro Characterization, Modelling, and Antioxidant Properties of Polyphenon-60 from Green Tea in Eudragit S100-2 Chitosan Microspheres.

Eudragit S100-coated chitosan microspheres (S100Ch) are proposed as a new oral delivery system for green tea polyphenon-60 (PP60). PP60 is a mixture of polyphenolic compounds, known for its active role in decreasing oxidative stress and metabolic risk factors involved in diabetes and in other chronic diseases. Chitosan-PP60 microspheres prepared by an emulsion cross-linking method were coated with Eudragit S100 to ensure the release of PP60 in the terminal ileum. Different core–coat ratios of Eudragit and chitosan were tested. Optimized chitosan microspheres were obtained with a chitosan:PP60 ratio of 8:1 (Ch-PP608:1), rotation speed of 1500 rpm, and surfactant concentration of 1.0% (m/v) achieving a mean size of 7.16 µm. Their coating with the enteric polymer (S100Ch-PP60) increased the mean size significantly (51.4 µm). The in vitro modified-release of PP60 from S100Ch-PP60 was confirmed in simulated gastrointestinal conditions. Mathematical fitting models were used to characterize the release mechanism showing that both Ch-PP608:1 and S100Ch-PP60 fitted the Korsmeyers–Peppas model. The antioxidant activity of PP60 was kept in glutaraldehyde-crosslinked chitosan microspheres before and after their coating, showing an IC50 of 212.3 µg/mL and 154.4 µg/mL, respectively. The potential of chitosan microspheres for the delivery of catechins was illustrated, with limited risk of cytotoxicity as shown in Caco-2 cell lines using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The beneficial effects of green tea and its derivatives in the management of metabolic disorders can be exploited using mucoadhesive chitosan microspheres coated with enteric polymers for colonic delivery.

Proapoptotic Activity of Propolis and Their Components on Human Tongue Squamous Cell Carcinoma Cell Line (CAL-27).

Propolis has been used since ancient times in folk medicine. It is a popular medicine possessing a broad spectrum of biological activities. This material is one of the richest sources of polyphenolic compounds such as flavonoids and phenolic acids. The ethanolic extract of propolis (EEP) evokes antibacterial, antiviral, antifungal and anticancer properties. Due to pharmacological properties it is used in the commercial production of nutritional supplements. In this study, gas chromatography coupled with mass spectrometry (GC-MS) was used to quantify main polyphenols in EEPs. The effect of EEPs, individual EEPs components (chrysin, galangin, pinocembrin, caffeic acid, p-coumaric acid, ferulic acid) and their mixture on viability of human tongue squamous cell carcinoma cell line (CAL-27) as well as the molecular mechanisms of the process were examined. The results of MTTs assay demonstrated that EEP, polyphenols and mixture of polyphenolic compounds were cytotoxic for CAL-27 cells in a dose dependent manner. The mechanism of cytotoxicity induced by these components undergoes through apoptosis as detected by flow cytometry. The ethanolic extracts of propolis activated caspases -3, -8, -9. Mixture of polyphenols was found as the most potent inducer of apoptosis thorough both intrinsic and extrinsic pathway. Therefore, we suggest that anticancer properties of propolis is related to synergistic activity of its main components.

Biologically active substances-enriched diet regulates gonadotrope cell activation pathway in liver of adult and old rats.

According to the Hippocrates’ theorem “Let food be your medicine and medicine be your food”, dietary interventions may induce changes in the metabolic and inflammatory state by modulating the expression of important genes involved in the chronic disorders. The aim of the present study was to evaluate the influence of long-term (14 months) use of biologically active substances-enriched diet (BASE-diet) on transcriptomic profile of rats’ liver. The experiment was conducted on 36 Sprague–Dawley rats divided into two experimental groups (fed with control or BASE-diet, both n = 18). Control diet was a semi-synthetic diet formulated according to the nutritional requirements for laboratory animals. The BASE-diet was enriched with a mixture of polyphenolic compounds, β-carotene, probiotics, and n-3 and n-6 polyunsaturated fatty acids. In total, n = 3,017 differentially expressed (DE) genes were identified, including n = 218 DE genes between control and BASE groups after 3 months of feeding and n = 1,262 after 14 months. BASE-diet influenced the expression of genes involved particularly in the gonadotrope cell activation pathway and guanylate cyclase pathway, as well as in mast cell activation, gap junction regulation, melanogenesis and apoptosis. Especially genes involved in regulation of GnRH were strongly affected by BASE-diet. This effect was stronger with the age of animals and the length of diet use. It may suggest a link between the diet, reproductive system function and aging.

The effects of tea polyphenols onCandida albicans: inhibition of biofilm formation and proteasome inactivation

The adherence of Candida albicans to one another and to various host and biomaterial surfaces is an important prerequisite for the colonization and pathogenesis of this organism. Cells in established biofilms exhibit different phenotypic traits and are inordinately resistant to antimicrobial agents. Recent studies have shown that black and green tea polyphenols exhibit both antimicrobial and strong cancer-preventive properties. Experiments were conducted to determine the effects of these polyphenols on C. albicans. Standard growth curves demonstrated a 40% reduction in the growth rate constant (K) with a 2 mg/mL concentration of Polyphenon 60, a green tea extract containing a mixture of polyphenolic compounds. Cultures treated with 1.0 micromol/L -(-)epigallocatechin-3-gallate (EGCG), the most abundant polyphenol, displayed a 75% reduction of viable cells during biofilm formation. Established biofilms treated with EGCG were also reduced, by 80%, as determined through XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) colorimetric assays. Identical concentrations of epigallocatechin and epicatechin-3-gallate demonstrated similar biofilm inhibition. Further investigations regarding the possible mechanism of polyphenol action indicate that in vivo proteasome activity was significantly decreased when catechin-treated yeast cells were incubated with a fluorogenic peptide substrate that measured proteasomal chymotrypsin-like and peptidyl-glutamyl peptide-hydrolyzing activities. Impairment of proteasomal activity by tea polyphenols contributes to cellular metabolic and structural disruptions that expedite the inhibition of biofilm formation and maintenance by C. albicans.

Provinol inhibits catecholamine secretion from the rat adrenal medulla.

The aim of the present study was to examine the effect of provinol, which is a mixture of polyphenolic compounds from red wine, on the secretion of catecholamines (CA) from isolated perfused rat adrenal medulla, and to elucidate its mechanism of action. Provinol (0.3~3 microg/ml) perfused into an adrenal vein for 90 min dose- and time-dependently inhibited the CA secretory responses evoked by ACh (5.32 mM), high K(+) (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic N(N) receptor agonist, 100 microM) and McN-A-343 (a selective muscarinic M(1) receptor agonist, 100 microM). Provinol itself did not affect basal CA secretion. Also, in the presence of provinol (1 microg/ml), the secretory responses of CA evoked by Bay-K-8644 (a voltage-dependent L-type dihydropyridine Ca(2+) channel activator, 10 microM), cyclopiazonic acid (a cytoplasmic Ca(2+)-ATPase inhibitor, 10 microM) and veratridine (an activator of voltage-dependent Na(+) channels, 10 microM) were significantly reduced. Interestingly, in the simultaneous presence of provinol (1 microg/ml) plus L-NAME (a selective inhibitor of NO synthase, 30 microM), the CA secretory responses evoked by ACh, high K(+), DMPP, McN-A-343, Bay-K-8644 and cyclpiazonic acid recovered to the considerable extent of the corresponding control secretion in comparison with the inhibition of provinol-treatment alone. Under the same condition, the level of NO released from adrenal medulla after the treatment of provinol (3 microg/ml) was greatly elevated in comparison to its basal release. Taken together, these data demonstrate that provinol inhibits the CA secretory responses evoked by stimulation of cholinergic (both muscarinic and nicotinic) receptors as well as by direct membrane-depolarization from the perfused rat adrenal medulla. This inhibitory effect of provinol seems to be exerted by inhibiting the influx of both calcium and sodium into the rat adrenal medullary cells along with the blockade of Ca(2+) release from the cytoplasmic calcium store at least partly through the increased NO production due to the activation of nitric oxide synthase.

Antihyperglycemic activity of polyphenolic components of black/bitter cumin Centratherum anthelminticum (L.) Kuntze seeds

The effect of black/bitter cumin seeds Centratherum anthelminticum (L.) Kuntze extract (CA) containing mixture of polyphenolic compounds was tested on rat intestinal α-glucosidases, human salivary α-amylase activity and postprandial hyperglycemia in rats. Polyphenolic components of C. anthelminticum seeds (CA) dose dependently inhibited rat intestinal disaccharidases. IC50 values were found to be 34.1 ± 3.8, 62.2 ± 4.5 and 500.5 ± 11.9 μg of CA for rat intestinal sucrase, maltase and p-nitrophenyl α-d-glucopyranoside (PNP-glycoside), respectively. CA also inhibited human salivary α-amylase activity with IC50 value of 185.5 ± 4.9 μg. The inhibitory effect of CA was found to be 8–32 fold more potent than dl-catechin but less effective than acarbose on rat intestinal disaccharidases and salivary α-amylase. The enzyme kinetic studies showed a non-competitive type of inhibition with a low Ki value of 30.24 μg, 76.67 μg and 341.60 μg of CA for maltase, sucrase and PNP-glycoside hydrolysis activities, respectively. The in vitro inhibition of glucosidases was further confirmed by in vivo maltose tolerance test in rats. Feeding of CA at 50–200 mg/kg body weight (b.wt) to maltose (2.0 g/kg b.wt), loaded rats significantly reduced the postprandial plasma glucose levels compared with acarbose. The inhibitory components of CA were identified as a mixture of polyphenolic compounds viz., gallic acid, protocatechuic acid, caffeic acid, ellagic acid, ferulic acid, quercetin and kaempferol. This study demonstrated that CA exerts antihyperglycemic effect by decreasing postprandial glucose in rats by modulating α- amylase and glucosidases (sucrase and maltase) activity and thus may be useful for the management of diabetes mellitus.