Phenolic Composition and Antioxidant Properties of Poplar Bud (Populus nigra) Extract: Individual Antioxidant Contribution of Phenolics and Transcriptional Effect on Skin Aging

Abstract

The Populus species possess great potential for therapeutical applications, especially for their known anti-inflammatory properties. The antioxidant properties of propolis, a hive product collected by honey bees mainly from poplar bud exudates, suggest that poplar buds also possess antioxidant properties. Here is reported the characterization of the antioxidant properties of an aqueous poplar bud (Populus nigra) extract. It presented a high total phenolic content, and moderate antioxidant properties as determined by ORAC assay. The main phenolic compounds identified were phenolic acids and flavonoid aglycons. These phenolic compounds were analyzed by ORAC assay for their individual antioxidant activity, in order to determine the major contributors to the total antioxidant activity of the extract. Thanks to their high antioxidant activity, caffeic and p-coumaric acids were identified as the major antioxidant components. Representing only 3.5% of its dry weight, these compounds represented together about 50% of the total antioxidant activity of the extract. The antioxidant properties of poplar bud extract and the phenolic compounds identified were also analyzed by cellular antioxidant activity assay (CAA), which was weakly correlated with ORAC assay. The transcriptional effect of poplar bud extract on skin aging was evaluated in vitro on a replicative senescence model of normal human dermal fibroblasts, using a customized DNA macroarray specifically designed to investigate skin aging markers. Among the detected genes, poplar bud extract significantly regulated genes involved in antioxidant defenses, inflammatory response and cell renewal. The collective antioxidant properties and transcriptional effect of this extract suggest potential antiaging properties which could be utilized in cosmetic and nutraceutical formulations.

Maca Cosmetics: A Review on Constituents, Therapeutics and Advantages

“…It indicates that the anti-radiation activity is the fundamental of anti-aging activity. In all, inflammatory response and oxidative stress mechanism are skin aging markers 84 . The substance of maca contains is related with anti-oxidant, anti-inflammatory and anti-radiation, in which phenolics is the major role of the therapeutics.…”

“…The substance of maca contains is related with anti-oxidant, anti-inflammatory and anti-radiation, in which phenolics is the major role of the therapeutics. Phenolics consist of several substances, which are capable of modulating signaling cascades of anti-aging and the effects of anti-aging that derives from the accumulation over a lifetime of oxidative damage to cells by reducing the oxygen species 84 and anti-inflammatory that can prevent UV-induced skin damage 85,86 . In addition, phenolics not only can recover the expression level in normal cells but also it can increase the cell numbers 84 .…”

Isolement, caractérisation et évaluation de l'activité antibactérienne de dérivés de dihydrochalcones hydroxycinnamylés issus de bourgeons de populus balsamifera L. /

“…Aucune information concernant la composition des proanthocyanidines de P. balsamifera n'a pu être relevée. Tous les composés phenoliques recensés ainsi que leurs structures et leurs provenances ont été compilés dans le tableau 7. davidiana a été associée à la présence de glycosides phénoliques (Zhang et al 2006b;Si et al 2009;Si et al 2011;Pal et al 2012) alors que celle des bourgeons de P. Nigra a été associée à la présence d'acides hydroxycinnamiques (Dudonné et al 2011). L'activité antioxydante de composés de la famille des acides hydroxycinnamiques a d'ailleurs été confirmée sur différents modèles in vitro et in vivo (Shahidi et Chandrasekara 2010).…”

“…L'activité antioxydante de composés de la famille des acides hydroxycinnamiques a d'ailleurs été confirmée sur différents modèles in vitro et in vivo (Shahidi et Chandrasekara 2010). En complément à l'activité antioxydante, il a été démontré que l'extrait de bourgeons de P. nigra pouvait aussi réguler certains gènes impliqués dans les défenses antioxydantes, la réponse inflammatoire et le renouvellement des cellules de la peau (Dudonné et al 2011 (Kurkin et al 2006). …”

“…Buds from several Populus species are covered with an exudate (Greenaway et Whatley 1990b;Eckenwalder 1996) that has attracted a growing interest in the scientific community since it has been identified as a known plant source of propolis (Bankova et al 2002;Salatino et al 2011). Propolis is a bee product that has been used in folk medicines around the world for the treatment of wounds and Antioxidant properties were also detected for Populus nigra bud extract (Dudonné et al 2011). Close relations between the chemical compositions of poplar type propolis and PBE suggest that PBE might be an interesting untapped source for the discovery of new bioactive compounds.…”