Anticarcinogenic activity

Tumorigenesis is a multistep process that begins with cellular transformation, progresses to hyperproliferation and culminates with the acquisition of invasive potential, angiogenic properties and establishment of metastatic lesions [256]. 

The major factors for human carcinogenesis are cigarette smoking, industrial emissions, gasoline vapours, infection and inflammation, nutrition and dietary 

Non-nutrient compounds in the diet have been found to exert inhibitory effects in experimental carcinogenesis [259, 260, 265-269]. Monoterpenes are non-nutritive dietary components found in the EOs of aromatic plants. Several experimental and population-based studies indicate that isoprenoids in the diet play an important role in the ability to avoid cancers [263, 266, 270-276]. 

Mechanistic studies revealed that the effects of limonene on cell proliferation and cell cycle progression were preceded by a decrease in cyclin D1 messenger RNA levels [284] and inhibition of posttranslational isoprenylation, rather than through the suppression of cholesterol biosynthesis [271 279, 285-293]. Limonene and perillyl alcohol and their active serum metabolites inhibit protein isoprenylation [287, 289-291, 294]. 

Although farnesol did not affect the prenylation of small G-proteins [295], the derivatized forms of farnesol inhibited methyltransferase activity [296-299] and suppressed the prenylation of G-proteins [300]. 

---

Linearly annelated esters, acids, and hydroxamic acids 132 showed antibacterial and anticarcinogenic activities (doses 0.2-2.0 g/day) [80JAP(K)2, 81JAP(K)1], whereas angularly annelated 133 has demonstrated MIC against Staphyloccocus aureus, Streptococcus biogenes, and Sarcina lutea (79JAP(K)I). 

Zhang Y, Kensler TW, Cho CQ Posner GH, Tallalay P. (1994) Anticarcinogenic activities of sulforaphane and structurally related synthetic norbomyl isothiocyanates. Proc Natl Acad Sci USA 91 3147-3150. 

Selenium is readily available in a variety of foods including shrimp, meat, dairy products, and grains, with a recommended daily intake of 55 to 70 jug. It occurs in several forms with Se+6 being biologically most important. Selenium is readily absorbed by the intestine and is widely distributed throughout the tissues of the body, with the highest levels in the liver and kidney. It is active in a variety of cellular functions and interacts with vitamin E. Selenium appears to reduce the toxic effects of metals such as cadmium and mercury and to have anticarcinogenic activity. Selenium produces notable adverse effects both in deficiency and excess thus recommended daily intake for adults is approximately 70 Jg/day but should not exceed 200 pg/day. 

Quinone reductase induction. Acetonitrile extract of the dried root, in cell culture at a concentration of 7.9 mg/g, was active on Hematoma-Mouse-lClC7. The sample was assayed for the induction of detoxifying enzymes that may have anticarcinogenic activity . 

Phytoestrogens Anticarcinogenic activity Branca and Lorenzetti (2005), Kwiatkowska (2007)... 

Anticarcinogenic Activity of CLA. Anticarcinogenic activity of synthetically prepared CLA was first tested in the two-stage mouse epidermal carcinogenesis model. In this study, 7 days, 3 days, and 5 min prior to 7,12-dimethylbenz[a]anthracene (DMBA) application, CLA was applied directly on the shaved backs of individual mice at doses of20,20, and 10 mg, respectively (7). Control mice were treated similarly with linoleic acid or acetone. All mice were given TPA to effect tumor promotion. It was found that CLA treated mice developed only about half as many papillomas and exhibited a lower tumor incidence than control mice. 

CLA as An Antioxidant. The complete mechanism of anticarcinogenic activity of CLA is not known. Some of the CLA effect is believed due to its antioxidant properties. For example, use of a water/ethanol system that is incubated at 40"C under air for 14 days, showed CLA reduced the oxidation of linoleic acid by 86% (8), Under the same conditions a-tocopherol reduced oxidation by only 63% and butylated hydroxytoluene (BHT) reduced oxidation by 92%. Dose-response studies were conducted, and it was found that the optimal ratio for CLA to protect linoleic acid from oxidation is 1 1000 (CLAilinoleic acid). 

Animal tissues, absorption and deposition of conjugated dienoic isomers of linoleic acid, 263-268 Anosmias, flavor chemicals, 19,2U Anticarcinogenic activity, conjugated dienoic derivatives of linoleic acid, 268-269... 

The flavonoids have long been recognized to possess anti-inflammatory, antioxidant, antiallergic, hepatoprotective, antithrombotic, antiviral, and anticarcinogenic activities. 

Thompson et al. (2005) reported that tumor cell proliferation and c-erbB2 expression decreased by 34% and 71%, respectively, whereas cell apoptosis increased (31%) in menopausal women fed a diet containing 25 g of flaxseed. Changes in c-erbB2 score and apoptosis index were correlated with total flaxseed intake whereas cell proliferation, as measured by Ki-67 labeling index, was not. A main conclusion from these studies was that the lignans and, to a lesser extent, ALA were responsible for the anticarcinogenic activity. 

Hydroxytyrosol has been also referred to as a potent agent with anticarcinogenic activity. Grape pomace is rich in a large number of polyphenolic compounds with high antioxidant activity, with resveratrol being probably the most known and referred to in the scientific literature. 

---