Postprandial fatty acid metabolism with coconut oil in young females: a randomized, single-blind, crossover trial.

BACKGROUND: Approximately 84% of the fatty acids contained in coconut oil (CO) are saturated fatty acids (SFAs), and approximately 47% of the SFA are lauric acid with 12 carbon atoms. Lauric acid carbon chain length is intermediate between medium and long-chain fatty acids (LCFAs). We examined how CO acts on lipid-related substances in the blood to determine whether its properties were similar to medium-chain fatty acids (MCFAs) or LCFAs. METHODS: This is a randomized controlled, single-blind, crossover study. Fifteen females were enrolled, using 3 test meals containing 30 g each of 3 different oils: CO (CO-meal), medium-chain triacylglycerol oil (MCT-meal), and long-chain triacylglycerol oil (LCT-meal). Blood samples were collected at fasted baseline and every 2 h for 8 h after the intake of each test meal. RESULTS: Repeated measures ANOVA of the ketone bodies and triglyceride (TG) showed an interaction between time and the test meal (P < 0.01 and P < 0.001, respectively). In subsequent Tukey's honestly significant difference (HSD) test of the ketone bodies, statistically significant differences were observed between the CO-meal and the LCT-meal (P < 0.05) 83.8 (95% CI, 14.7, 153.0) and between the MCT-meal and the LCT-meal (P < 0.05) 79.2 (95% CI, 10.0, 148.4). The incremental area under the curve (iAUC) and maximum increase in very low-density lipoprotein cholesterol (VLDL-C) and intermediate-density lipoprotein cholesterol (IDL-C) were the lowest for CO-meal intake. CONCLUSIONS: The characteristics of lauric acid contained in CO, including the kinetics of ß-oxidation and effects on blood TG, were very similar to those of MCFA. Moreover, regarding the iAUC and peak increment, VLDL-C and IDL-C were the lowest with the CO-meal. These results suggest that the intake of CO after fasting does not increase the TG, VLDL-C, and IDL-C, and may help prevent dyslipidemia. This trial was registered at UMIN (URL of registration: https://www.umin.ac.jp) as UMIN000019959.

Characterization of the Ca2+-coordination structures of L- and T-plastins in combination with their synthetic peptide analogs by FTIR spectroscopy.

FTIR spectroscopy was employed to characterize the coordination structures of divalent cations (M2+ = Ca2+ or Mg2+) bound by L- and T-plastins, which contain two EF-hand motifs. We focused on the N-terminal headpieces in the L- and T-plastins to analyze the regions of COO- stretching and amide-I in solution. The spectral profiles indicated that these headpieces have EF-hand calcium-binding sites because bands at 1551 cm-1 and 1555 cm-1 were observed for the bidentate coordination mode of Glu at the 12th position of the Ca2+-binding site of Ca2+-loaded L-plastin and T-plastin, respectively. The amide-I profile of the Mg2+-loaded L-plastin headpiece was identical with that of the apo L-plastin headpiece, meaning that L-plastin has a lower affinity for Mg2+. The amide-I profiles for apo, Mg2+-loaded and Ca2+-loaded T-plastin suggested that aggregation was generated in protein solution at a concentration of 1 mM. The implications of the FTIR spectral data for these plastin headpieces are discussed on the basis of data obtained for synthetic peptide analogs corresponding to the Ca2+-binding site.