Cellular uptake of anthocyanins extracted from black soybean, grape, and purple sweet potato using INT-407 cells

Abstract

This study combined in vitro digestion and INT-407 cells to evaluate the bioaccessibility of anthocyanins in the small intestinal epithelial cells. Black soybean, grape, and purple sweet potato were chosen as they have a different anthocyanin composition. After the aqueous extract was digested under in vitro gastric and intestinal conditions, the digested mixture was incubated in the media of INT-407 for 2 h at 37 °C. Low proportion (< 0.3%) of anthocyanins in black soybean and grape passed through cell membranes. Cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside in black soybean and cyanidin-3-O-(6-O-p-coumaroyl)-5-O-diglucoside and delphinidin-3-O-(6-O-p-coumaroyl)-5-O-diglucoside in grape were found inside the cell. However, acylated anthocyanins containing three sugar moieties in purple sweet potato were not detected inside the cell. p-Coumaric acid was detected in the cells incubated with grape, but not in the media. These indicate that chemical structure of anthocyanins affected their cellular uptake and antioxidant activity in INT-407 cells.

Supplementary information: The online version contains supplementary material available at 10.1007/s10068-021-00976-y.

Keywords: Anthocyanin; Antioxidant activity; Cellular uptake; INT-407; p-Coumaric acid.

Fig. 1

Chemical structures of anthocyanidins

Fig. 2

HPLC–DAD chromatograms of cell lysates from INT-407 cells incubated with in vitro digested of black soybean, purple sweet potato, and grape. Absorbance was monitored at 520 nm for black soybean and grape and 530 nm for purple sweet potato. Peak assignments are presented in Table 1

Fig. 3

Antioxidant activity of the cell lysates obtained from INT-407 cells incubated with in vitro digested black soybean, purple sweet potato, or grape. Values with different letters on the bar are significantly different at p < 0.05