Anthocyanins in Mesocarp/Epicarp and Endocarp of Fresh Acai (Euterpe oleracea Mart.) and their Antioxidant Activities and Bioavailability

Abstract

We measured anthocyanin levels in fresh açai (Euterpe oleracea Mart.), a native Amazonian palm fruit; cyanidin-3-O-glucoside (C3G) and cyanidin-3-O-rutinoside (C3R) in mesocarp/epicarp portion were 5.49 and 13.0 mg/g extracts, respectively, and these amounts were remarkably higher than that in endocarp. Hydrophilic ORAC assay suggested that açai mesocarp/epicarp extracts had potent antioxidant activity compared to blueberry extract. Following, absorption and excretion of açai anthocyanins were evaluated. After oral administration of açai extracts (400 mg/kg body weight) to rats, C3G and C3R appeared as intact forms in the plasma as maximum amounts of 101.0 ± 55.6 nmol/L at 60 min and 537.0 ± 99.1 nmol/L at 120 min after administration, respectively. Most of these anthocyanins were excreted in urine by 2 h post-administration time. In conclusion, fresh açai contained hydrophilic antioxidants including C3G and C3R, and therefore has strong antioxidant potency especially in the mesocarp/epicarp portion. Upon consumption, açai anthocyanins appeared as intact forms in plasma.Keywords: açai, anthocyanin, antioxidant activity, ORAC *To whom correspondence should be addressed. E-mail: kumazawa@u-shizuoka-ken.ac.jp † These authors contributed equally to this work IntroductionAnthocyanidins are important plant pigments responsible for red, blue and purple colors. Generally, anthocyanidins widely exist as glycoside derivatives, so-called anthocyanins, in colored fruits and vegetables, such as berries (Sakakibara, et al., 2003;Maatta-Riihinen, et al., 2004;Wu, et al., 2006;Koponen, et al., 2007;Ogawa, et al., 2008). Anthocyanidins and anthocyanins have been shown to exhibit a range of biological effects, including antioxidant activity, anticarcinogenesis, induction of apoptosis, anti-obesity, antidiabetes, and prevention of DNA damage (Rice-Evans, et al., 1996;Sakakibara, et al., 2002;Hou, 2003;Katsube, et al., 2003;Tsuda, et al., 2003;Cooke, et al., 2006;Duthie, 2007;Sasaki, et al., 2007;Tsuda, 2008). Interestingly, recent research suggests that anthocyanins can also prevent oxidative stress resulting from psychological stress (Rahman, et al., 2008). Consequently, the regular consumption of foods rich in anthocyanins has been considered to be associated with a reduced risk of developing chronic diseases (Harborne and Williams, 2000;Zafra-Stone, et al., 2007).Açai (Euterpe oleracea Mart.) is a palm plant widely distributed in the Amazonian area, especially Brazil. Açai is a multi-stemmed plant as shown in Fig. 1A, and its fruit looks similar to blueberry in appearance. The size of an individual açai fruit is about 1 to 1.5 cm in diameter. An outer, edible layer composed of mesocarp and very thin epicarp covers a lone, fibrous seed, consisting of the endocarp and endosperm (Fig. 1B). A ripened açai appears dark purple in color due to high amounts of anthocyanins, predominantly cyanidin-3-Oglucoside (C3G) and cyanidin-3-O-rutinoside (C3R) (Fig. 2) (Gallori, et al., 2004), indicating that açai might be one anthocyanin-rich foo...

Antiangiogenic and Antioxidant In Vitro Properties of Hydroethanolic Extract from açaí (Euterpe oleracea) Dietary Powder Supplement

“…The oxidative protective effects here described may be attributed to the presence of anthocyanins in AHE, predominantly cyanidin-3- O -rutoside and cyanidin-3- O -glucoside, as found by Jensen et al [ 36 ]. In fact, anthocyanins have been described as the main contributors for açaí antioxidant properties [ 7 , 12 , 26 , 40 , 41 ]. Açaí pulp extracts, rich in anthocyanins, also exhibit health beneficial properties (e.g., neuroprotective and cardioprotective) by mechanisms dependent on their antioxidant properties [ 42 , 43 , 44 ].…”

The Use of Euterpe oleracea Mart. As a New Perspective for Disease Treatment and Prevention

“…Pacheco-Palencia et al [ 29 ] states that extracts enriched with these compounds are responsible for antioxidant activity. Moreover, Agawa et al [ 30 ] and Poulose et al [ 31 ] reported the presence of the flavonoid quercetin and anthocyanins, such as cyanidin-3-glucoside and cyanidin-3-rutinoside ( Figure 1 and Table 1 ) in EO extracts, confirming their antioxidant activity. Poulose et al [ 31 ] also reported an anti-inflammatory effect, corroborating the results of Kang et al [ 32 ], Cedrim et al [ 33 ], and Mathias et al [ 34 ].…”

“…Due to the EO fruit chemical composition, its application becomes desirable because of the high concentrations of metabolites responsible for significant antioxidant activity [ 30 , 31 , 36 , 39 ]. The patent BR 102017007451-0 A2 [ 108 ], published in 2018 ( Table 4 ), discloses the formulation of tablets, capsules, granulates and controlled-release pharmaceutical preparations from ethanolic EO extracts.…”

Bioavailability of Plant-Derived Antioxidants

“…The two glycosides were also detected in urine after 2 h from administration. However, there was no attempt to correlate bioavailability to in vivo antioxidant activity of the detected glycosides [ 89 ].…”