Nobuya Inaba

Antioxidative Effect of Citrus Essential Oil Components on Human Low-density Lipoprotein In Vitro

We studied the antioxidative action to evaluate the effect of citrus essential oil components on human LDL in vitro. Among the authentic volatile compounds tested, γ-terpinene showed the strongest antioxidative effect, and inhibited both the Cu2+-induced and AAPH-induced oxidation of LDL. γ-Terpinene added after 30 min (mid-lag phase) and 60 min (propagation phase) of incubation of LDL with Cu2+ inhibited LDL oxidation.

Effects of γ-Terpinene on Lipid Concentrations in Serum Using Triton WR1339-Treated Rats

We studied lipid metabolism to evaluate the effects of γ-terpinene on suppression of increases in serum lipid concentrations using Triton WR1339-treated rats. At 6 hr after Triton WR1339 injection, the total cholesterol and triglyceride concentrations in the γ-terpinene group underwent statistically significant decreases (18.3 and 30.3%, respectively) compared with those of the Triton-treated group.

Phenolics Profile of Mume, Japanese Apricot(Prunus mume Sieb. et Zucc.)fruit

The fruit of mume, Japanese apricot (Prunus mume Sieb. et Zucc.), was evaluated for its phenolics content, high performance liquid chromatography (HPLC) profile and antioxidative activities. The phenolics content of mume fruit was relatively high, the flesh of fully matured fruit containing up to 1% of phenolics on a dry weight basis. Reflecting such a high content of phenolics, the ORAC (oxygen radical absorbance capacity) value for mume fruit flesh showed high values, ranging from 150 to 320 µmol/g Trolox equivalent, depending upon the stage of maturation. 5-O-Caffeoylqunic acid (chlorogenic acid), 3-O-caffeoylquinic acid and tetra-O-acylated sucrose-related compounds were isolated from the flesh of mume fruit, although many unknown peaks were also apparent in the HPLC chromatogram. An alkali hydrolysate comprised four main phenolic acids, caffeic acid, cis/trans-p-coumaric acid and ferulic acid. No flavonoids were observed in the analysis. These results suggest that the majority of phenolics in mume fruit were hydroxycinnamic acid derivatives.