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Propolis from the Uruguayan Savanna, main features
The antioxidant capacity of propolis from the southern region of Uruguay was evaluated by in vitro and cellular tests. The free radical scavenging capacity was evaluated by ORAC, obtaining values significantly higher than those of other natural products (8000 μmol Trolox equiv / g propolis). ORAC values correlated well with total polyphenol content (determined by the Folin-Ciocalteu method) and UV absorption. The total content of polyphenols (150 mg gallic acid equiv / g propolis) and flavonoids (45 mg quercetin equiv / g propolis) were similar to the values reported for propolis from southern Brazil (group 3) and from Argentina. The flavonoid composition determined by RP-HPLC indicates a strong poplar origin. High polyphenol samples effectively inhibit low-density lipoprotein lipoperoxidation and tyrosine nitration. Furthermore, Uruguayan propolis was found to induce the expression of endothelial nitric oxide synthase and inhibit endothelial NADPH oxidase, suggesting a potential cardiovascular benefit by increasing the bioavailability of nitric oxide in the endothelium. |
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