Comparison of methods for proanthocyanidin extraction from pine (Pinus densiflora) needles and biological activities of the extracts

Flavonoids are known to be effective scavengers of free radicals. In particular, proanthocyanidins are flavonoids that possess cardiovascular protection, antioxidative activities, and immunomodulatory activities. Here, we evaluated proanthocyanidin contents in the total polyphenolic compounds of pine needle extracts prepared by hot water, ethanol, hexane, hot water-hexane (HWH), and hot water-ethanol (HWE). Analysis of each extract indicated that the ethanol extract contained the highest proanthocyanidin concentration. The HWH and hexane extracts also contained relatively high concentrations of proanthocyanidin. On the other hand, proanthocyanidin content analyses out of the total polyphenolic compounds indicated that the HWH extract contained the highest content. These results suggest that HWH extraction is a suitable method to obtain an extract with a high level of pure proanthocyanidins and a relatively high yield. The HWH extract possessed superior activity in diverse antioxidative analyses such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferrous ion chelating (FIC), and ferric-ion reducing power (FRAP) assays. In addition, upon assessing the effects of the pine needle extracts on macrophages (Raw 264.7 cell), the HWH extract exhibited the highest activity. In this study, we discerned an efficient extraction method to achieve relatively pure proanthocyanidins from pine needles and evaluated the biological functions of the resulting extract, which could potentially be used for its efficacious components in functional food products.

Assessment of Endogenous Nitric Oxide Formation in the Neonate : Measurement of Urinary Nitrite and Citrulline Concentrations

PURPOSE: At birth, as the fetus adjusts to the "new world", the fetal pulmonary circulation undergoes a striking transition, characterized by an immediate rise in pulmonary blood flow and a sustained decrease in pulmonary vascular resistance(PVR). In the factors which reduce PVR after birth, are ventilation of the lung by gas, increase of oxygen tension in pulmonary vascular system, and some vasoactive mediators. Nitric oxide(NO) is regarded as one of the vasoactive mediators. Therefore we attempted to determine endogenous NO formation in newborns by measuring urinary nitrite(NO2) and citrulline which are indexes of endogenous NO formation. METHODS: We measured the urinary excretion of NO2 and citrulline in 20 term and 15 preterm neonates at the age of 1, 3, 7 days. RESULTS: The urinary excretion of NO2 and citrulline in the neonate group was higher as compared with the older children group(P<0.05). And it increased from the 1st to the 3rd day in the neonatal period(P<0.05). Furthermore the urinary excretion of them and the gestational age were inversely related(P<0.05). CONCLUSION: These changes of the urinary excretion of NO2 and citrulline in the neonate group suggest the presence of an active physiological role of NO in the pulmonary vascular biology during neonatal transition.