Effects Of Plant Polyphenols Research Articles

P123 Additive antitumor effect of plant polyphenols and a synthetic inhibitors of polyamines biosynthesis

P123 Additive antitumor effect of plant polyphenols and a synthetic inhibitors of polyamines biosynthesis

Effect of Plant Polyphenols on Adipokine Secretion from Human SGBS Adipocytes

Introduction. Adipose tissue contributes to atherosclerosis with mechanisms related to adipokine secretion. Polyphenols may exhibit antiatherogenic properties. The aim of the study was to investigate the effects of three polyphenols, namely, quercetin, epigallocatechin gallate (EGCG), and resveratrol on adipokine secretion from cultured human adipocytes. Methods. Human SGBS adipocytes were treated with quercetin, EGCG, and resveratrol for 24 and 48 hours. Visfatin, leptin, and adiponectin were measured in the supernatant. Results. Visfatin secretion was inhibited by quercetin 10 μM by 16% and 24% at 24 and 48 hours respectively. The corresponding changes for quercetin 25 μM were 47% and 48%. Resveratrol 25 μM reduced visfatin by 28% and 38% at 24 and 48 hours. EGCG did not have an effect on visfatin. None of tested polyphenols influenced leptin and adiponectin secretion. Conclusion. Quercetin and resveratrol significantly decreased visfatin secretion from SGBS adipocytes. This effect may contribute to their overall antiatherogenic properties.

Effects of plant polyphenols on ovarian follicular reserve in aging ratsThis paper is one of a selection of papers published in this special issue entitled “Second International Symposium on Recent Advances in Basic, Clinical, and Social Medicine” and has undergone the Journal's usual peer review process.

The pool of ovarian primordial follicles is established during embryonic development or at birth. During the development from primordial to primary, secondary, and antral follicles, only a small portion of follicles can mature and successfully ovulate; the others are destined to degenerate through apoptotic or atretic loss. As aging advances, females ultimately enter the cessation phase of the estrous cycle and are no longer capable of fertilization. The presumption is that if we can slow down the process of folliculogenesis or decrease follicle loss, females may have a larger ovarian follicular reserve and a longer reproductive lifespan. In our study, rats underwent intragastric administration with tea polyphenols, quercetin (meletin), genistein, or resveratrol, once a day for 4 months (from age 12 to 15 months), to test whether they have positive effects on follicular reserve or ovarian functions. The results showed that rats treated with tea polyphenols (27.8 +/- 3.2) and quercetin (36.5 +/- 4.1) had a comparable number of healthy follicles to those of controls (26.9 +/- 3.8), although significantly fewer atretic follicles were observed in the tea polyphenol group (43.4 +/- 5.9 vs 79.7 +/- 7.5; p < 0.001). Remarkably, both genistein- and resveratrol-treated rats had more healthy follicles (respectively, 42.8 +/- 3.9, p < 0.05; and 51.9 +/- 6.4, p < 0.001) and fewer atretic follicles (respectively, 58.4 +/- 8.0, p < 0.05; and 51.0 +/- 6.2, p < 0.01) than controls. These results indicate that genistein and resveratrol can increase the ovarian follicular reserve and prolong the ovarian lifespan in rats, and their positive effects may be not only due to their intervention in the transition from primordial to primary follicle, but also due to the inhibiting effect on follicular atresia.

The effects of plant polyphenols on enterotoxigenic Escherichia coli adhesion and toxin binding

Pigs frequently encounter bacterial infections like enterotoxigenic Escherichia coli (ETEC). Due to rising concerns about antibiotic resistance of bacteria, there is a large demand for natural alternatives to combat these ETEC infections. Plant polyphenols have been suggested to reduce both the binding of cholera toxin to the GM1 ganglioside and the adhesion of uropathogenic E. coli to F1 fimbriae . In this study different commercial natural polyphenol extracts were evaluated for their possible effect on ETEC. Out of the three polyphenol extracts tested two exert inhibitory effects on the heat-labile toxin binding and all three extracts reduced the binding of ETEC to brush borders. The presence of protein abolished labile toxin binding properties of polyphenols. This makes it unlikely that these polyphenols could be used as an actual feed additive to combat ETEC caused diarrhea.