- Polyphenols, Green Tea and Cancer
The main constituents of green tea, the polyphenols (epigallocatechin, epicatechin gallate, and epicatechin) show inhibition of various cancer cell lines, such as lung, mammary, and stomach. To determine how tea polyphenols induce growth inhibition of cancer cells, the inhibitory potential of each tea polyphenol on the growth of a human lung cancer cell line was examined. All three polyphenols demonstrated the same potency. A DNA graph after treatment with EGCG was similar to that after treatment with genistein, suggesting that EGCG induces the G2 phase (preparation for division) arrest in cancer cells. It was also found that EGCG was incorporated into the liquid medium of the cytoplasm, as well as the nuclei. These results provide new insights into the mechanisms of action of EGCG and green tea extract as cancer-preventive agents in humans.
Japanese Journal of Cancer Research, 1997, Vol 88, Iss 7, pp 639-643.
- Preventing Bone Metastasis
This study investigated the effect of Bisphosphonates on breast and prostate carcinoma cell adhesion to bone extracellular matrices. Bisphos-phonates (BPs) are powerful inhibitors of osteoclast (cells associated with absorption and removal of bone) activity. Pretreatment of tumor cells with Bisphosphonates inhibited tumor cell adhesion to the bone matrices. In contrast, the Bisphosphonates did not affect adhesion of normal cells (fibroblasts) to extracellular matrices and they did not exert any cytotoxic effects. These results provide evidence for a direct cellular effect of Bisphosphonates in preventing tumor cell adhesion to bone, and suggest a prophylactic treatment of patients with cancer that is known to preferentially metastasize to bone. Cancer Research, 1997, Vol 57, Iss 18, pp 3890-3894
- Fish Oil and Cardiac Events
In a randomized, placebo-controlled study, the effects of treatment with fish oil (eicosapentaenoic acid, 1.08 g/day) and mustard oil (alpha-linolenic acid, 2.9 g/day) were compared for 1 year in 122 patients. After 1 year total cardiac events were significantly less in the fish oil and mustard oil groups compared with the placebo group (24.5% and 28% vs. 34.7%). Nonfatal infarctions were also significantly less in the fish oil and mustard oil groups (13.0% and 15.0% vs. 25.4%). The fish oil group had significantly less cardiac deaths compared with the placebo group (11.4% vs. 22.0%). The fish oil and mustard oil groups also showed a significant reduction in total cardiac arrhythmias, left ventricular enlargement, and angina pectoris compared with the placebo group. A part of the benefit may be caused by the reduction in oxidative stress. The findings of this study suggest that fish oil and mustard oil, possibly due to the presence of n-3 fatty acids, may provide rapid protective effects in patients with acute myocardial infarction (AMI). Cardiovascular Drugs and Therapy, 1997, Vol 11, Iss 3, pp 485-491
- Beta-Carotene and Retinol
The relationship between nonfatal acute myocardial infarctions (AMI) and the intake of beta-carotene and retinol was investigated. A study was conducted between 1983 and 1992 in northern Italy on 433 women with nonfatal AMI and 869 controls. The results indicate that the risk of nonfatal AMI in women is inversely related to intake of beta-carotene containing foods, but not foods containing retinol. European Journal of Epidemiology, 1997, Vol 13, Iss 6, pp 631-637
- Telomerase and Brain Tumors
Telomerase activity appears to play a significant role in human brain tumors. This study examined Telemerase activity in 41 brain tumor cases. The results showed telemerase activity was demonstrated in 17 cases of glioblastomas, oligodendrogliomas, and metastatic brain tumors. These results suggest that telomerase activity may be an important marker of brain tumor malignancy. Furthermore, the change from negative activity to positive activity in the recurrent tumors appeared to be a useful prognosticator for malignant astrocytic tumor. Cancer, 1997, Vol 80, Iss 3, pp 471-476
- Melatonin And Free Radicals
A study was conducted to determine the effect of melatonin on hydroxyl free radical formation during cerebral ischemia-reperfusion in rats. The result was a decrease in the production of toxic dihydroxybenzoic acid during ischemia for 16-30 minutes and reperfusion for 1-30 minutes, showing that melatonin inhibits the production of free radicals during reduced blood flow to the brain. Acta Pharmacologica Sinica, 1997, Vol 18, Iss 5, pp 394-396
- L-Deprenyl and Longevity
This study assessed whether L-deprenyl treatment begun in later life might enhance the longevity of dogs in a fashion similar to that documented in rodents. The survival was recorded in a subset of elderly dogs who were between the ages of 10 and 15 yrs at the start of tablet administration and who received tablets for at least 6 months. In this subset, dogs in the L-deprenyl group survived longer than dogs in the placebo group. Twelve of 15 (80%) dogs in the L-deprenyl group survived to the conclusion of the study, in contrast to only 7 of 18 (39%) of the dogs who received placebo. Furthermore, by the time the first L-deprenyl treated dog died on day 427, 5 placebo treated dogs had already succumbed, the first one on day 295. These findings suggest daily oral administration of 1 mg/kg L-deprenyl prolongs life when begun in relatively healthy dogs 10-15 years of age and maintained for the duration of the individuals life, but for no less than six months. Life Sciences, 1997, Vol 61, Iss 11, pp 1037-1044
- Deprenyl, Sex and Learning
L-Deprenyl is an MAO (monoamine oxidase) inhibitor which also stimulates the action potential-transmitter release and coupling of neurons (catecholaminergic activity enhancer, CAE) in the brain. In this study, lifelong treatment with 0.25 mg/kg of L-deprenyl enhanced the sexual and learning performance of both sexually inactive and highly active rats and prolonged their life. Sexually inactive animals lived 152 weeks compared to 134 weeks for the control group; the highly active group lived 185 weeks compared to 151 weeks. Also, the release of action potential-transmitters during the crucial development phase of life (between weaning and second month of age) was significantly higher than either before or after that period. This indicates that a transmitter release and coupling of neurons (CAE mechanism) starts working with high intensity after weaning, lasts until the completion of full scale sexual development, and shows an unparalleled decay thereafter. It was concluded that the CAE regulation in the brain, stimulated by L-deprenyl, controls general activity and consequently the longevity of rats
Experimental Gerontology, 1997, Vol 32, Iss 4-5, pp 539-552
- Benefits of Soy ProteinTwo groups of Golden Syrian hamsters were fed cholesterol-enriched semipurified diets containing either 40% casein or soybean protein concentrate for a period of 8 weeks. Compared to the casein-containing diet, animals fed the soybean protein concentrate had significant reductions in plasma total cholesterol and very low density and low density lipoprotein cholesterol with no significant effects on high density lipoprotein cholesterol. Plasma triglycerides were also significantly reduced in the soybean protein concentrate fed hamsters compared to the casein-fed animals. Compared to the casein-fed hamsters, the degree of aortic fatty streak involvement was reduced by 76% in the soybean protein concentrate-fed hamsters. There was a significant correlation between total cholesterol and aortic fatty streak area. Thus, this study demonstrates the incidence of abnormally low levels of cholesterol from soybean protein concentrate relative to casein are associated with a striking reduction in aortic fatty streak formation. Nutrition Research, 1997, Vol 17, Iss 9, pp 1457-1467
- Vitamin C and Prostate CancerTreatment of human prostate cancer cells with vitamin C in a dose and time-dependent manner showed a decrease in cell viability. Vitamin C inhibited cell division and growth through the production of hydrogen peroxide, which damages the cells probably through an as yet unidentified free radical generation/mechanism. The results indicate that oxygen free radicals are involved in vitamin C-induced damage in the cancer cells. These results also suggest that vitamin C is a potent anticancer agent for prostate cells. Prostate, 1997, Vol 32, Iss 3, p 188-195
- Leukemia and Vitamin D3Human promyelocytic leukemia cells cultured in the presence of vitamin D3 for 3 years exhibited a reduced rate of tumor growth when injected into mice. Cells grown in 40 nM of vitamin D3 failed to form detectable tumors in 11 out of the 12 inoculated mice. These results suggest a mechanism for the reported chemopreventive effects of sunlight-generated vitamin D3 or dietary vitamin D3.
Proceedings of the Society for Experimental Biology and Medicine, 1997, Vol 215, Iss 4, pp 399-404
- Phytoestrogens and Prostate CancerA 66-year-old man took phytoestrogen 160 mg, four times a day every day for one week, before undergoing radical prostatectomy for moderately high-grade adenocarcinoma. The excised portion of the specimen from the patient showed prominent apoptosis (programmed cell death), which was typical of a response to high-dose estrogen therapy and which is also suggestive of tumor regression. There were no adverse side effects from the treatment. The scientiests concluded that further studies of the effects of phytoestrogens in prostate cancer be warranted. Medical Journal of Australia, 1997, Vol 167, Iss 3, pp 138-140
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