Enhanced Absorption of Anthocyanins after Oral Administration of Phytic Acid in Rats and Humans

Abstract

Many studies on the bioavailability of polyphenols have been reported. However, the relative urinary excretions of AC are also low, ranging from 0.004% to 0.1%. By contrast, other polyphenols show higher urinary excretion levels. Here, we studied the enhancing effects of phytic acid (IP6) on absorption of blackcurrant anthocyanins (BCAs) in rats and humans. In rats after oral administration of BCAs (as 241 mg of AC/kg body weight) in IP6 (0%, 0.25%, 0.5%, 1%, 2.5%) solution, the ACs recovery in urine was increased dependent on IP6 dose. These results suggest that the IP6 enhances gastrointestinal absorption of ACs. At the further analysis of IP6 enhancement effect in rat, whereas BCAs were normally passed through the stomach and duodenum within 2 h, in IP6 group, after 2-6 h post-administration, stomach and jejunum content's weights were specifically heavy, and large amounts of ACs were also detected in stomach, duodenum, and jejunum. These results suggested that the mixture of BCAs and IP6 reduced the gastrointestinal motility. Prolongation of ACs residue in gastrointestinal tract then caused the enhancing effects of IP6 on absorption of AC. In the human study, each subject was orally administrated a BCA beverage containing BCA concentrate (AC 4 mg/kg body weight), 1% of IP6, and 1% of sodium citrate as a pH stabilizer. Both the plasma level and the urinary excretion of AC were increased as compared to BCA administration without IP6. AC intake with IP6 may increase the bioavailability of AC to the comparative level as other polyphenols. Yet, phytic acid, being a strong chelator of important minerals, contributes to mineral deficiencies. An interference with iron uptake has been reported. Safety tests are therefore necessary before high dose IP6 can be used in foods.

Dietary anthocyanin‐rich plants: Biochemical basis and recent progress in health benefits studies

“…In terms of interactions with other compounds, quercetin was found to inhibit C3G uptake [24]. On the other hand, when blackcurrant anthocyanins (BA) and phytic acid were simultaneously administered, the blood concentration of anthocyanin was significantly increased in both rats and humans compared with the administration of BA alone [25]. In humans, intake of cream did not affect the C max of pelargonidin-O-glucuronide (an anthocyanin metabolite), but raised its T max [26].…”

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

“…Absorption patterns of anthocyanins have been reported to be strongly affected by other ingredients. For example, when phytic acid is administered with anthocyanins, phytic acid enhances gastrointestinal absorption of anthocyanins (Matsumoto, et al, 2007). Hence, açai probably contains some ingredients to enhance and/or change the absorption patterns of anthocyanins, especially C3G.…”

Anthocyanins and human health: How gastric absorption may influence acute human physiology

“…Interestingly, slowing the rate of gastric emptying by co-administering phytic acid [61] or cream [62] increased anthocyanin absorption, again showing that the stomach is a significant site of absorption of these pigments.…”