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Though the price makes you wince, you might just buy that bottle of your favorite olive oil anyway. Perhaps it's exactly what you want for the salad dressing you're making [...]

Although epidemiologic evidence and animal studies suggest that olive oil may prevent the onset of cancer, the components responsible for such an effect and their mechanisms of action remain largely unknown. In the present study, we investigated the effect of a virgin olive oil phenol extract (PE) on proliferation, the cell cycle distribution profile, apoptosis, and differentiation of the human promyelocytic cell line HL60. PE inhibited HL60 cell proliferation in a time- and concentration-dependent manner, as demonstrated by the viable cell count and 3-[4,5-dimethyl(thiazol-2-yl)]-3,5-diphenyltetrazolium bromide (MTT) metabolism. Cell growth was completely blocked at a PE concentration of 13.5 mg/L; apoptosis was also induced as detected by fluorescence microscopy and flow cytometry. Determination of the cell cycle distribution by flow cytometry revealed an accumulation of cells in the [G.sub.0]/[G.sub.1] phase. Two compounds isolated from PE, the dialdehydic forms of elenoic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) and to tyrosol (pHPEA-EDA), were shown to possess properties similar to those of PE; they account for a part of the powerful effects exerted by the complex mixture of compounds present in PE. The concentrations of the different compounds in PE were determined by HPLC, and the purity of 3,4-DHPEA-EDA and pHPEA-EDA was ascertained by NMR. Treatment with PE induced a differentiation in HL60 cells, which subsequently acquired the ability to produce superoxide ions and reduce nitroblue tetrazolium to formazan. These results support the hypothesis that polyphenols play a critical role in the anticancer activity of olive oil. KEY WORDS: * olive oil * phenols * apoptosis * differentiation * chemoprevention

Previous studies proposed a protective role of the dietary intake of (n-3) PUFA in human inflammatory bowel disease (IBD), but almost no studies have been performed using olive oil. The aims of the present study were to test the beneficial effects of an olive oil-based diet with or without fish oil, rich in (n-3) PUFA, in the dextran sodium sulfate (DSS) model of rat colitis and to elucidate the mechanisms involved in their potential beneficial effects, with special attention to the production of some of the mediators involved in the intestinal inflammatory response, such as leukotriene [B.sub.4] ([LTB.sub.4]), tumor necrosis factor [alpha] (TNF[alpha]) and nitric oxide (NO). Rats were fed the different diets for 2 wk before colitis induction and thereafter until colonic evaluation 15 d later. Colitic rats fed the olive oil-based diet had a lower colonic inflammatory response than those fed the soybean oil diet, and this beneficial effect was increased by the dietary incorporation of (n-3) PUFA. A restoration of colonic glutathione levels and lower colonic NO synthase expression occurred in all colitic rats fed an olive oil diet compared with the control colitic group that consumed the soybean oil diet. However, (n-3) PUFA incorporation into an olive oil diet significantly decreased colonic TNF [alpha] and [LTB.sub.4] levels compared with colitic rats that were not supplemented with fish oil. These results affirm the benefits of an olive oil diet in the management of IBD, which are further enhanced by the addition of (n-3) PUFA. KEY WORDS: * rat experimental colitis * leukotriene [B.sub.4] * nitric oxide synthase * (n-3) polyunsaturated fatty acid * tumor necrosis factor

Byline: Diego L. Garcia-Gonzalez (1), Luisa Mannina (2,3), Marco D'Imperio (2), Anna Laura Segre (3), Ramon Aparicio (1) Keywords: Olive oil; Hazelnut oil; 1.sup.H-NMR; 13.sup.C-NMR; Artificial neural network Abstract: The lack of any official analytical method to detect the adulteration of olive oil with a low percentage of hazelnut oil is explained by the similarities in the chemical compositions of both kinds of oils. To counter this problem, an artificial neural network based on 1.sup.H-NMR and 13.sup.C-NMR data has been developed to detect olive oil adulteration, and the results from this ANN are presented here. A training set consisting of hazelnut oils, pure olive oils, and olive oils blended with 2--20% hazelnut oils was used to design and train a multilayer perceptron with 100% correct classifications. This mathematical model was also validated using an external validation set of blend samples (3--15%) and genuine samples. The detection limit of the model was around 8%. Author Affiliation: (1) Instituto de la Grasa (CSIC), Padre Garcia Tejero 4, 41012, Sevilla, Spain (2) Facolta di Agraria, Dipartimento S.T.A.A.M., Universita degli Studi del Molise, 86100, Campobasso, Italy (3) Istituto di Metodologie Chimiche, CNR, 00016 Monterotondo Stazione, Roma, Italy Article History: Registration Date: 20/07/2004 Received Date: 22/03/2004 Online Date: 12/08/2004

Interest in the in vivo biological activities of olive oil phenolics is rapidly growing, and different models and vehicles of administration are used worldwide. Matters of practicality determine the use of rats rather than humans as the model of choice. Also, growing interest in nutraceuticals is leading to the formulation of compounds containing olive oil phenols. In this study, we compared metabolism and urinary excretion of hydroxytyrosol [(HT), the most representative phenol of olive oil] between rats and humans by evaluating excretion of HT and its major metabolite, homovanillyl alcohol. Also, we compared human excretion of HT when consumed as a natural component of extra virgin olive oil, when added to refined olive oil, or when added to yogurt (as an approximation of functional food). Urinary excretion of HT was greater in humans than in rats, a species with a high basal excretion of HT and its metabolites. The high (234% of HT administered) excretion of free HT suggests that hydrolysis of oleuropein administered in humans (still an unresolved issue) occurs in vivo. Moreover, human HT excretion was much higher after its administration as a natural component of olive oil (44.2% of HT administered) than after its addition to refined olive oil (23% of HT administered) or yogurt (5.8% of dose or ~13% of that recorded after virgin olive oil intake). These data suggest that the rat is not the appropriate model for the study of HT metabolism and that HT-containing functional foods should be carefully formulated. KEY WORDS: * hydroxytyrosol * oleuropein * nutraceuticals * polyphenols * antioxidants

The effects of certain polyphenolic compounds in red wine, such as resveratrol and quercetin, have been widely investigated to determine the relationship between dietary phenolic compounds and the decreased risk of cardiovascular diseases. However, the effects of polyphenolic compounds contained in other foods, such as olive oil, have received less attention and little information exists regarding the biological activities of the phenol fraction in olive oil. The aim of this study was to evaluate the antiplatelet activity and antioxidant power of two isochromans [1-(3'-methoxy-4'-hydroxy-phenyl)-6,7-dihydroxy-isochroman (encoded L116) and 1-phenyl-6,7-dihydroxyisochroman (encoded L137)] recently discovered in olive oil and synthesized in our laboratory from hydroxytyrosol. These compounds were effective free radical scavengers and inhibited platelet aggregation and thromboxane release evoked by agonists that induce reactive oxygen species-mediated platelet activation including sodium arachidonate and collagen, but not ADP. Release of tritiated arachidonic acid from platelets was also impaired by L116 and L137. These results indicate that other Mediterranean diet nutraceuticals also exhibit antioxidant activity that could be beneficial in the prevention of vascular diseases. KEY WORDS: * isochromans * antioxidant * platelet aggregation * olive oil * cardiovascular diseases