Phytosterol oxidation products are absorbed in the intestinal lymphatics in rats but do not accelerate atherosclerosis in apolipoprotein E-deficient mice

Hiroko Tomoyori, Yayoi Kawata, Tomoko Higuchi, Ikuyo Ichi, Hiroyoshi Sato, Masao Sato, Ikuo Ikeda, Katsumi Imaizumi

Research output: Contribution to journalArticlepeer-review

72 Citations (Scopus)

Abstract

Phytosterol oxidation products (oxyphytosterols) are formed during the processing and storage of foods. However, it is unknown whether oxyphytosterols affect human health. To address these issues, we prepared β-sitosterol and campesterol oxides, evaluated their lymphatic absorption in rats, and examined the effect of an oxyphytosterol diet on atherosclerosis in apolipoprotein (apo) E-deficient mice. The lymphatic absorption of cholesterol and 6 oxyphytosterols (7α-hydroxy, 7β-hydroxy, β-epoxy, α-epoxy, dihydroxy, and 7-keto) of β-sitosterol or campesterol was assessed in thoracic duct-cannulated rats fed an AIN-93G-based diet containing 2.5 g of cholesterol, oxyphytosterols, or intact phytosterols per kg. Lymphatic recoveries (on a mass basis) of oxycampesterols (15.9 ± 2.8%, n = 10) and oxysitosterols (9.12 ± 1.77%, n = 10) were higher than for campesterol (5.47 ± 1.02%, n = 12, P < 0.05) and β-sitosterol (2.16 ± 0.37%, n = 12, P < 0.05), but lower than for cholesterol (37.3 ± 8.3%, n = 6, P < 0.05). Apo E-deficient mice were fed an AIN-93G-based diet containing 0.2 g oxyphytosterols or intact phytosterols per kg for 9 wk. Diet-derived oxyphytosterols accumulated in the serum, liver, and aorta. Furthermore, the oxyphytosterol diet increased oxycholesterol in the serum compared to the phytosterol diet. However, there was no significant difference between the 2 groups in the serum and aortic cholesterol concentration, the lesion area in the aortic root, or 8-iso-prostaglandin F2α concentration in the urine. These results indicate that exogenous oxyphytosterols are well-absorbed and accumulate in the body, but do not promote the development of atherosclerosis in apo E-deficient mice.

Original languageEnglish
Pages (from-to)1690-1696
Number of pages7
JournalJournal of Nutrition
Volume134
Issue number7
DOIs
Publication statusPublished - 2004 Jul

Keywords

  • Absorption
  • Atherosclerosis
  • Oxyphytosterol
  • Phytosterol

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

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