14E-4 |
Almond (Prunus Amygdalus) skin proanthocyanidin as antioxidant and modulator of arachidonic acid metabolism in human HT-29 colon cancer cell line |
W. S. JEONG1, J. Hong2, and P. A. Lachance1. (1) Dept. of Food Science, Rutgers, The State Univ. of New Jersey, The Nutraceuticals Institute, 65 Dudley Rd., New Brunswick, NJ 08901-8520, (2) College of Pharmacy, Rutgers, The State Univ. of New Jersey, 125 Susan L. Cullman Lab. for Cancer Research, 164 Frelinghuysen Rd., Piscataway, NJ 08854 Epidemiological studies have shown that certain components of fruits, vegetables, grains, and nuts may prevent or reduce the risk of some chronic diseases such as cancer and cardiovascular disease. Almond is the most popular tree nut in the USA with 70 % of the world’s supply. The consumption of almond has been reported to lower LDL cholesterol while preserving HDL cholesterol in humans and to reduce colon cancer risk in animals. Arachidonic acid metabolism is believed to play an important role in various human diseases such as inflammation and cancer. The enzymes participating in arachidonic acid metabolism as well as the eicosanoids metabolites have been found at elevated levels in various human cancer cells. A bioactivity-guided fractionation of almond skin was carried out using various column chromatographic techniques and biological assays including antioxidant and arachidonic acid release inhibition assays. Several fractions from almond skin extract have strong antioxidant activities. In addition, some fractions showed significant inhibition of arachidonic acid metabolism in the HT-29 human colon cancer cell both at the enzymatic level as well as in the intact cell line. Several analytical tools have revealed that the active fraction of almond skin contains significant amounts of proanthocyanidins. Various techniques such as the depolymerization reaction and LC-MS have shown that the proanthocyanidin purified from almond skin has a polymer structure with (-)-epicatechin as an extension unit and with the polymerization degree of 5 or higher. The almond skin proanthocyanidin significantly inhibited arachidonic acid release in HT-29 cell at levels as low as 1 mg/ml and showed stronger DPPH radical scavenging activity than BHT at 10 ppm. These results indicate that almond skins serve as an overlooked source of nutraceuticals in particular their antioxidant and arachidonic acid cascade inhibitor properties.
Session 14E, Nutraceuticals & Functional Foods: General I
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