OLIO DI RISO E GAMMA-ORIZANOLO (FITOSTEROLI DEL RISO

ABSTRACTS tratti da      

PubMed, a service of the National Library of Medicine, provides access to over 12 million MEDLINE citations back to the mid-1960's and additional life science journals. PubMed includes links to many sites providing full text articles and other related resources.

Nutritional and biochemical aspects of the hypolipidemic action of rice bran oil: a review. 

Author: Rukmini C; Raghuram TC 
Address: National Institute of Nutrition, Indian Council of Medical Research, Hyderabad. 
Source: J Am Coll Nutr, 10(6):593-601 1991 Dec

In this paper, we review the effects of rice bran oil (RBO), an unconventional oil recently introduced onto the Indian market for human use. 

RBO contains oleic acid (38.4%), linoleic acid (34.4%), and linolenic acid (2.2%) as unsaturated fatty acids, and palmitic (21.5%) and stearic (2.9%) acids as saturated fatty acids. 

The unsaponifiable fraction (4.2%) has total tocopherols (81.3 mg%), gamma-oryzanol (1.6%), and squalene (320 mg%). 

Oryzanol is a mixture of Ferulic acid esters of triterpene alcohols such as Cycloartenol (CA) (106 mg%) and 24-methylene Cycloartanol (494 mg%).

 Studies on experimental rats demonstrated a hypolipidemic effect of RBO. The unsaponifiable fraction of RBO lowers cholesterol levels.
Feeding phytosterols, CA, and 24-methylene cycloartanol in amounts present in RBO to hypercholesterolemic rats for 8 weeks indicates that CA alone reduces cholesterol and triglyceride levels significantly.
Endogenous sterol excretion increases in animals given CA.
The accumulation of CA in the liver inhibits cholesterol esterase activity, which in turn leads to reduction in circulating cholesterol levels. Cycloartenol is structurally similar to cholesterol and may compete with the binding sites of cholesterol and sequestrate cholesterol, which is metabolized to its derivatives.

RBO, which is rich in tocopherols and tocotrienols, may improve oxidative stability. Tocotrienols inhibit HMG CoA reductase, resulting in hypocholesterolemia. The hypolipidemic effect of RBO has also been established in human subjects. Thus, RBO could be a suitable edible oil for patients with hyperlipidemia.

L'olio di riso e il gamma orizanolo in numeri: Tabelle

Phytother Res 2001 Jun;15(4):277-89

Atherosclerosis and Dysmetabolic Disease Study Center 'G. Descovich', Clinical Medicine and Applied Biotechnology Dept. 'D. Campanacci', University of Bologna, Italy. afgcicero@tiscalinet.it
Diet is the first (and sometimes the only) therapeutic approach to hyperlipoproteinaemias.

Rice bran oil and its main components (unsaturated fatty acids, triterpene alcohols, phytosterols, tocotrienols, alpha-tocopherol) have demonstrated an ability to improve the plasma lipid pattern of rodents, rabbits, non-human primates and humans, reducing total plasma cholesterol and triglyceride concentration and increasing the high density lipoprotein cholesterol level.
Other potential properties of rice bran oil and gamma-oryzanol, studied both in vitro and in animal models, include modulation of pituitary secretion, inhibition of gastric acid secretion, antioxidant action and inhibition of platelet aggregation. 
This paper reviews the available data on the pharmacology and toxicology of rice bran oil and its main components with particular attention to those studies relating to plasma lipid altering effects. Copyright 2001 John Wiley & Sons, Ltd.

Title: Effects of gamma-oryzanol on serum lipids and apolipoproteins in dyslipidemic schizophrenics receiving major tranquilizers. 
Author: Sasaki J; Takada Y; Handa K; Kusuda M; Tanabe Y; Matsunaga A; Arakawa K 
Address: Department of Internal Medicine, School of Medicine, Fukuoka University, Japan. 
Source: Clin Ther, 12(3):263-8 1990 May-Jun 

The subjects were 20 chronic schizophrenic patients with dyslipidemia (total cholesterol levels greater than or equal to 220 mg/dl, triglycerides greater than or equal to 150 mg/dl, or high-density lipoprotein cholesterol less than or equal to 40 mg/dl) who had been receiving neuroleptics for a mean of ten years.
Each patient was given 100 mg of gamma-oryzanol three times daily for 16 weeks. 
Total cholesterol decreased, from 204 at baseline to 176 mg/dl at week 12.
Low-density lipoprotein cholesterol level decreased significantly from 124 mg/dl at baseline to 101 mg/dl at week 12.
High-density lipoprotein cholesterol levels were 36.1 mg/dl at baseline and 35.9 mg/dl at week 12.
Apolipoprotein (apo) B levels decreased significantly from 116 mg/dl to 101 mg/dl at week 16;
Apo A-II levels increased significantly from 31.7 mg/dl to 34.7 mg/dl;
Apo B/apo A-I ratio declined significantly from 0.99 to 0.84. 
No treatment side effects were recorded. It is concluded that gamma-oryzanol is safe and effective in the treatment of dyslipidemia. 

Current Therapeutic Res. 45(4),543-552 (1989)
Effects of gamma-Orizanol on Hyperlipidemic Subjects
Yoshino, G., Kazuni, T., Amano, M. Takeiwa, M., Yamasaki, T.
The hypocholesterolemic effect of gamma oryzanol was investigated in 67 patients with hyperlipidemia: 35 (WHO type IIa), 19 (IIb), 13 (IV).
300 mg of gamma Oryzanol were administered daily for 3 months.
In type IIa and IIb patients, plasma cholesterol (251 ± 7 and 268 ± 8 mg/dl, respectively) significantly decreased from the second month (8% and 12% respectively; P<0.001)
The mean plasma triglyceride levels of all subjects decreased significantly after three months 
(p< 0.05).
HDL-Cho lipoprotein was also significantly elevated in the type IIb subjects after three months.
The reduction in plasma-cholesterol was attributable to the decrease in LDL-Cho lipoprotein in the type IIa and IIb subjects.
Thus a mild but significant hypocholesterolemic effect of gamma-oryzanol was observed.
Together with a long term history of clinical use, this indicates the potential use of this drug as a treatment of first choice for mild hypercholesterolemia.