Dietary triacylglycerol hydroperoxide is not absorbed, yet it induces the formation of other triacylglycerol hydroperoxides in the gastrointestinal tract

Takumi Takahashi; Shunji Kato; Junya Ito; Naoki Shimizu; Isabella Supardi Parida; Mayuko Itaya-Takahashi; Masayoshi Sakaino; Jun Imagi; Kazuaki Yoshinaga; Aya Yoshinaga-Kiriake; Naohiro Gotoh; Ikuo Ikeda; Kiyotaka Nakagawa

doi:10.1016/j.redox.2022.102471

Dietary triacylglycerol hydroperoxide is not absorbed, yet it induces the formation of other triacylglycerol hydroperoxides in the gastrointestinal tract

Redox Biol. 2022 Nov:57:102471. doi: 10.1016/j.redox.2022.102471. Epub 2022 Sep 14.

Affiliations

¹ Laboratory of Food Function Analysis, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan.
² Laboratory of Food Function Analysis, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan; J-Oil Mills Innovation Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan.
³ J-Oil Mills Innovation Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan.
⁴ Faculty of Food and Agricultural Sciences, Fukushima University, Fukushima, Japan.
⁵ Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan.
⁶ Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo, Japan.
⁷ Laboratory of Food Function Analysis, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan; J-Oil Mills Innovation Laboratory, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan. Electronic address: kiyotaka.nakagawa.c1@tohoku.ac.jp.

Abstract

The in vivo presence of triacylglycerol hydroperoxide (TGOOH), a primary oxidation product of triacylglycerol (TG), has been speculated to be involved in various diseases. Thus, considerable attention has been paid to whether dietary TGOOH is absorbed from the intestine. In this study, we performed the lymph duct-cannulation study in rats and analyzed the level of TGOOH in lymph following administration of a TG emulsion containing TGOOH. As we successfully detected TGOOH from the lymph, we hypothesized that this might be originated from the intestinal absorption of dietary TGOOH [hypothesis I] and/or the in situ formation of TGOOH [hypothesis II]. To determine the validity of these hypotheses, we then performed another cannulation study using a TG emulsion containing a deuterium-labeled TGOOH (D2-TGOOH) that is traceable in vivo. After administration of this emulsion to rats, we clearly detected unlabeled TGOOH instead of D2-TGOOH from the lymph, indicating that TGOOH is not absorbed from the intestine but is more likely to be produced in situ. By discriminating the isomeric structures of TGOOH present in lymph, we predicted the mechanism by which the intake of dietary TGOOH triggers oxidative stress (e.g., via generation of singlet oxygen) and induces in situ formation of TGOOH. The results of this study hereby provide a foothold to better understand the physiological significance of TGOOH on human health.

Keywords: Intestinal absorption; Liquid chromatography-tandem mass spectrometry; Oxidative stress; Stable isotope-labeling; Triacylglycerol hydroperoxide.