Ryuji Ochiai

Dr. Ryuji Ochiai

Kao Corporaiton
orcid

Research Focus & Metrics

Academic Career Length

40Years (1987-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2002 in American Journal of Hypertension
Verified
Journal Article
Closed access
ASAtsushi Suzuki
Atsushi Suzuki
DKD. Kagawa
D. Kagawa
AFA. Fujii
A. Fujii
RORyuji Ochiai
Ryuji Ochiai
ITI. Tokimitsu
I. Tokimitsu
ISI. Saito
I. Saito
Ferulic acid (4-hydroxy-3-methoxycinnamic acid) is a phenolic compound contained in rice bran and other plants. The effect of ferulic acid on blood pressure (BP) was investigated in spontaneously hypertensive rats (SHR). After oral administration of ferulic acid (1 to 100 mg/kg) to SHR, systolic blood pressure (SBP) significantly decreased in a dose-dependent manner. When oral ferulic acid (50 mg/kg) was administered to SHR, BP was lowest at 1 h and returned to basal levels at 6 h. There was a significant correlation between SHR plasma ferulic acid and changes in the SBP of the tail artery, suggesting that absorbed ferulic acid reduces BP. When 7-week-old SHR were given 10 and 50 mg/kg/d of ferulic acid for 6 weeks, increases in BP were significantly attenuated compared to SHR on the control diet. Intravenous injection of ferulic acid dose dependently reduced carotid arterial pressure in anesthetized SHR. Furthermore, the depressor effect of intravenous ferulic acid (1 mg/kg) was significantly attenuated by pretreatment of SHR with the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 3 mg/kg, administered intravenously). These data suggest that the hypotensive effect of ferulic acid in SHR is associated with NO-mediated vasodilation.

1 January 2002 in Hypertension Research
Verified
Journal Article
Closed access
PDF file
ASAtsushi Suzuki
Atsushi Suzuki
DKDaiji Kagawa
Daiji Kagawa
RORyuji Ochiai
Ryuji Ochiai
ITIchiro Tokimitsu
Ichiro Tokimitsu
ISIkuo Saito
Ikuo Saito
Japan's largest platform for academic e-journals: J-STAGE is a full text database for reviewed academic papers published by Japanese societies

1 January 2004 in Hypertension Research
Verified
Journal Article
Closed access
PDF file
RORyuji Ochiai
Ryuji Ochiai
HJHiroko Jokura
Hiroko Jokura
ASAtsushi Suzuki
Atsushi Suzuki
ITIchiro Tokimitsu
Ichiro Tokimitsu
MOMitsuru Ohishi
Mitsuru Ohishi
TOToshio Ogihara
Toshio Ogihara
Our previous study revealed the antihypertensive effects of green coffee bean extract (GCE) ingestion in spontaneously hypertensive rats. We suggested that this antihypertensive action was due to the fact that GCE contains chlorogenic acid (CQA) as a major phenolic compound, and CQA in turn contains ferulic acid as a metabolic component that acts on nitric oxide (NO) derived from the vascular endothelium. In this study, the effects of GCE on blood vessels were evaluated in healthy males. The subjects were 20 healthy males with reduced vasodilation responses measured by strain gauge plethysmograms (SPG) to ischemic reactive hyperemia. Of the 20 subjects, 10 (mean age, 37.2 years) ingested a test drink containing GCE (CQA: 140 mg/day), and the other 10 (mean age, 34.8 years) ingested a placebo drink for 4 months. During the ingestion period, SPG, pulse wave velocity (PWV), and serum biochemical parameters were measured, and acceleration plethysmograms (APG) were taken. The reactive hyperemia ratio (RHR) in the test drink group began to increase after ingestion for 1 month and was significantly higher (p <0.05) than that in the placebo group after ingestion for 3 months and 4 months. In addition, after ingestion for 4 months, the test drink group showed a significant decrease (p <0.01) in the plasma total homocysteine level compared with the pre-ingestion level. However, there were no significant differences in PWV or APG between the test drink group and the placebo drink group. The improvement in RHR after ingestion of a drink containing GCE suggested an improvement in vasoreactivity by this component. (Hypertens Res 2004; 27: 731-737)

1 July 2003 in Planta Medica
Verified
Journal Article
Closed access
PDF file
DKDaiji Kagawa
Daiji Kagawa
HJHiroko Jokura
Hiroko Jokura
RORyuji Ochiai
Ryuji Ochiai
ITIchiro Tokimitsu
Ichiro Tokimitsu
HTHirokazu Tsubone
Hirokazu Tsubone
It has been reported that cedarwood oil has sedative effects when inhaled. In this study, we evaluated sedative effects of inhaled cedrol, which is a major component of cedarwood oil. Accumulative spontaneous motor activity was significantly decreased in the cedrol-exposed Wistar rats. Similar results were confirmed in caffeine-treated Wistar rats, spontaneously hypertensive rats (SHR), and ddY mice. In addition, exposure to cedrol prolonged pentobarbital-induced sleeping time in Wistar rats. To investigate whether cedrol, which has a very faint aroma, affects the olfactory system, the nasal cavities of Wistar rats were treated with zinc sulfate to reduce olfactory function. Two days later, the pentobarbital-induced sleep time was measured as described above. Compared to intact rats, the sleep prolongation effect was decreased in a lavender-roman chamomile mixed oil exposure positive control group, indicating that olfactory function was impaired. In contrast, prolongation of the sleeping time did not change in the cedrol exposure group. The above findings indicate that cedrol inhalation had marked sedative effects regardless of the animal species or the functional state of the autonomic nerves, suggesting that the mechanism of action is via a pathway other than the olfactory system.

20 September 2018 in Nutrients
Verified
Journal Article
Open access
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KSKatsuyoshi Saitou
Katsuyoshi Saitou
RORyuji Ochiai
Ryuji Ochiai
KKKazuya Kozuma
Kazuya Kozuma
HSHirotaka Sato
Hirotaka Sato
TKTakashi Koikeda
Takashi Koikeda
YKYoshihisa Katsuragi
Yoshihisa Katsuragi
(1) Background: Chlorogenic acids (CGAs) have been attracting interest of late, owing to their health benefits. Here, we performed a randomized, double-blind, placebo-controlled trial to investigate whether CGAs improved cognitive function in humans. (2) Methods: Thirty-eight healthy participants were assigned to either the CGA group, which was given CGA-added beverage daily for 16 weeks, or the placebo group. Cognitive functions were assessed using the Japanese version of the CNS Vital Signs (Cognitrax). (3) Results: The CGA group showed significant increase in the Cognitrax domain scores for motor speed, psychomotor speed, and executive function compared with the placebo group, as well as an improvement in the shifting attention test scores. In blood analysis, the CGA group showed increased levels of apolipoprotein A1 and transthyretin, both of which are putative biomarkers for early-stage cognitive decline. (4) Conclusions: These results suggest that CGAs may improve some cognitive functions, which would help in the efficient performance of complex tasks.

1 January 2018 in Evidence-Based Complementary and Alternative Medicine
Verified
Journal Article
Open access
PDF file
MKMorimasa Kato
Morimasa Kato
RORyuji Ochiai
Ryuji Ochiai
KKKazuya Kozuma
Kazuya Kozuma
HSHirotaka Sato
Hirotaka Sato
YKYoshihisa Katsuragi
Yoshihisa Katsuragi
Objective. To evaluate the effect of chlorogenic acids (CGAs) intake on cognitive function. Methods. In this pilot study, the Cogstate and CNS Vital Signs test batteries were used to evaluate cognitive function in 8 healthy elderly men and women complaining of subjective memory loss after a 6‐month intake of a test beverage containing 330 mg of CGAs just before bedtime. Results. After a 6‐month CGA intake period, significant improvement was observed in the One Back Test of the Cogstate, the Shifting Attention Test, and Finger Tapping Test as well as in the composite memory, verbal memory, complex attention, cognitive flexibility, executive function, and motor speed domains of the CNS Vital Signs test battery. Conclusion. A 6‐month intake of CGAs may improve attentional, executive, and memory functions in the elderly with complaints of subjective memory loss.