12-hydroxy oleic acid impairs endothelium-dependent vasorelaxation.

Diesel and biodiesel emissions exposures reduce vascular responsiveness in vivo, but the components of PM responsible for this effect are poorly understood. Fatty acids (FAs) represent a significant fraction of the compounds that make up organic combustion by-products, and may be involved in vascular responses following inhalation. It was hypothesized that vascular tissue exposed to a model FA might impair responses to vasoactive agonists ex vivo. Rat aortic rings were exposed to oleic acid or 12-hydroxy oleic acid and responses determined by myography. 12-Hydroxy oleic acid was found to significantly reduce endothelium-dependent vasodilation at sub-cytotoxic concentrations. This approach demonstrates the potential for FAs, especially oxidized forms, to play a role in the vascular responses observed following air pollution exposure.

Allergic contact dermatitis from 12-hydroxystearic Acid and hydrogenated castor oil.

A 34-year-old male experienced severe allergic contact dermatitis from 12-hydroxystearic acid in a lip balm and from hydrogenated castor oil in an underarm deodorant. He also had a positive patch-test reaction to bis-diglyceryl polyacyladipate-2, which is present in the implicated lip balm and which itself contains 12-hydroxystearic acid. He was also incidentally found to have contact allergy to ricinoleic acid and castor oil. Ricinoleic acid is the principal fatty acid in castor oil, whereas 12-hydroxystearic acid is the principal fatty acid in hydrogenated castor oil. These two fatty acids are each 18-carbon 12-hydroxylated fatty acids, differing only in degree of saturation. The lack of patch-test reactivity to the analogous nonhydroxylated fatty acids, stearic acid (C18:0), and oleic acid (C18:1) indicates that 12-hydroxylation was required for allergenicity in this patient. In addition, serial dilution testing demonstrated that saturation of the hydroxylated C18 fatty acid enhanced its allergenicity.

Overview of the preparation, use and biological studies on polyglycerol polyricinoleate (PGPR).

The esterification of condensed castor oil fatty acids with polyglycerol gives a powerful water-in-oil emulsifier which is used by the food industry in tin-greasing emulsions and as an emulsifier with lecithin in chocolate couverture and block chocolate. A safety evaluation programme was undertaken in the late 1950s and early 1960s to determine whether this food emulsifier polyglycerol polyricinoleate (PGPR). (Quest International trade name ADMUL WOL) presented any health implications for consumers. This programme included acute toxicity tests, subacute rat and chicken toxicity studies, a rat chronic toxicity/multigeneration reproduction study, rodent metabolism, carcinogenicity testing in rat and mouse and a human clinical evaluation. PGPR was found to be 98% digested by rats and utilized as a source of energy superior to starch and nearly equivalent to groundnut oil. There was no interference with normal fat metabolism in rats or in the utilization of fat-soluble vitamins. Despite the intimate relationship with fat metabolism, no evidence was found of any adverse effects on such vital processes as growth, reproduction and maintenance of tissue homeostasis. PGPR was not carcinogenic in either 2-year rat or 80-week mouse feeding studies. The human studies showed no adverse effects on tolerance, liver and kidney function, and fat balance at levels up to 10 g/day PGPR. The acceptable daily intake for PGPR which was set by JECFA in 1974 and the EC/SCF in 1979 is 7.5 mg/kg body weight/day. The UK FAC in 1992 estimated that the maximum per capita mean daily intake of PGPR is 2.64 mg/kg body weight/day. It can be concluded that the use of ADMUL WOL brand of PGPR in tin-greasing emulsions or in chocolate couverture does not constitute a human health hazard.

Human studies on polyglycerol polyricinoleate (PGPR).

A series of toxicology studies was conducted in the 1950s and 1960s to investigate the toxicity of ADMUL WOL, a brand of polyglycerol polyricinoleate (PGPR). A component of these investigations included studies in human subjects. During 1964 and 1965, PGPR was fed to 19 human volunteers whose diet contained constant levels of fat and protein. Up to 10 g/day PGPR was fed to each volunteer in soups, cakes and toffee bars for 2 weeks. Pre-exposure normal values of biochemical parameters were established. Fat balance tests confirmed that digestion and absorption of PGPR took place. No consistent effect of PGPR on the various biochemical parameters was observed, nor had PGPR any toxic effect on liver and kidneys. The consumption of PGPR by humans produced no adverse effects. The quantities consumed, up to 10g/day, was equivalent to approximately 63 times the estimated maximum per capita mean daily intake by man of 2.64 mg kg body weight/day. It is therefore concluded from this study that the consumption of ADMUL WOL, a brand of PGPR, has no adverse effects in man.

Therapeutic modalities for mechanical cleansing of the colon.

Mechanical cleansing of the colon is an accepted standard of practice prior to colon surgery, and endoscopic and radiographic procedures. Cleansing the bowel prior to these procedures increases the accuracy of the diagnostic procedures and decreases the morbidity and mortality following surgery, where fecal contamination is a concern. Mechanical cleansing agents are sometimes used for acute constipation, but because of the extent and harshness of the evacuation they induce, and because of their adverse effects, they are not used for long-term management of constipation. Dosages vary among products, procedures, and individuals. Manufacturer guidelines should be consulted for proper dosing and administration.

Cytotoxicity of ricinoleic acid (castor oil) and other intestinal secretagogues on isolated intestinal epithelial cells.

Epithelial cells were isolated from hamster small intestine by a technique of vibration and used to measure cytotoxicity in vitro of certain substances known to stimulate intestinal fluid secretion. These secretagogues have laxative properties and produce mucosal damage in vivo. Compounds tested were ricinoleic acid (caster oil), dioctyl sodium sulfosuccinate, oleic acid, sodium deoxycholate and sodium cholate. Cytotoxicity was assessed by: 1) exclusion of trypan blue; 2) release of intracellular (prelabeled) 51Cr; and 3) inhibition of cellular uptake of 3-O-methylglucose. Ricinoleate produced a dose-dependent (0.1-2.0 mM) cytotoxicity as assessed by all three methods. Oleic acid, a nonhydroxylated analog of ricinoleate, was less potent. The dihydroxy bile acid, deoxycholate, was equipotent with ricinoleate, was less potent. The dihydroxy bile acid, deoxycholate, was equipotent with ricinoleate but its trihydroxy congener, cholate, was less potent. Dioctyl sodium sulfosuccinate had cytotoxicity similar in magnitude to that of ricinoleate and deoxycholate. Cytotoxicity of these agents to isolated cells may relate to their secretory potential in vivo, their abilities to produce structural change at the mucosal surface and their laxative properties.