RESUMEN
This study was designed to optimize the extraction rate of total polyphenols and ellagic acid from pomegranate flowers. Single factors were investigated for liquid-to-material ratio (5-25), ethanol concentration (20%-60%), sonication time (5-60 min), and sonication power (150-500 W). The level range of the Box-Bokhen design was determined with respect to the single-factor results. The components of each index were normalized using the entropy weighting method for obtaining the comprehensive evaluation value. Under the actual conditions, the final optimization results were 17 for liquid-to-material ratio, 43% for ethanol concentration, 10 min for ultrasonic time, and 300 W for ultrasonic power. The extracts obtained under optimal conditions were tested for the inhibition of Streptococcus mutans and its biofilm, and results showed that pomegranate flowers exerted some inhibitory effects on the bacterium. Phosphomolybdenum and FRAP assays were used, and DPPH, ABTS, and O2- radical scavenging tests were conducted, indicating that pomegranate flower extracts have good antioxidant capacity.
Asunto(s)
Granada (Fruta) , Antioxidantes/farmacología , Ácido Elágico , Etanol , Flores , Extractos Vegetales , PolifenolesRESUMEN
Pomegranate flowers is an ancient medicine that has commonly been used to treat various diseases such as diabetes. However, no reports are available on the metabolic profile of pomegranate flowers in vivo. In the present study, with the aid of HPLC-Q-TOF-MS2, 67 compounds were identified in pomegranate flowers extract, including 18 ellagitannins, 14 gallic acid and galloyl derivatives, five anthocyanins and 18 flavonoids. Seven compounds were firstly identified. In vivo, 22 absorbed compounds and 35 metabolites were identified in rat biosamples (urine, feces, plasma and tissues) after orally administered with pomegranate flowers extract. This result showed that not all compounds abundant in pomegranate flowers extract could be absorbed well in plasma and tissues. This finding also suggested a potential correlation between study on metabolic profile of these compounds in vivo and study on strategy of screening bioactivity of the isolates with in vitro cell systems evaluation. Notably, mono-glucuronide conjugated metabolite of ellagitannin compound (corilagin) was firstly identified. In addition, this is first report to identify phase II conjugate metabolites of ellagitannins in vivo after oral administration of ellagitannins-rich extracts (or foods). Thus, characterizing its multiple constitution, absorption and metabolic fate of these compounds in vivo is helpful to better analyze the active components in pomegranate flowers.