Plant compounds for cancer shine at conference

Held from December 5th to 8th, the American Association for Cancer Research held its Sixth Annual International Conference on Frontiers in Cancer Prevention Research in Philadelphia, Pennsylvania. For the conference, the role of these plant compounds was heavier on the therapeutic potential, but it nonetheless reflects the growing scientific clout that rests behind these nutraceuticals. The compounds on which research was presented included those from black raspberries, as well as antioxidants from other berries and from green extract. Researchers from the University of Sydney presented a study they conducted on a commercially available nutrition drink they found to reduce the growth of tumors by 25 percent in a mouse model of human prostate cancer. The drink, called Blueberry Punch, contains blueberry, red grape, raspberry and elderberry concentrates, as well as grape seed and skin extract, citrus skin extracts, green tea extract (EGCG), olive leaf and olive pulp extracts, tarragon, turmeric and ginger. The researchers believe the combined effect of the different ingredients was what was so effective. "We have undertaken efficacy studies on individual components of Blueberry Punch, such as curcumin, resveratrol and EGCG, in the same laboratory setting and found these effective in suppressing cell growth in culture,"​ said Jas Singh, a research fellow at the university. "While individual phytochemicals are successful in killing cancer cells, we reasoned that synergistic or additive effects are likely to be achieved when they are combined."​ After 72 hours of exposure to increasing concentrations of the punch, the prostate cancer cells in the study exhibited a dose-dependent reduction in size and viability when compared with untreated cells. After feeding mice a ten percent solution of the mixture for two weeks, the tumors in the mice were 25 percent smaller than for those mice drinking only tap water. The study was partially funded by the makers of Blueberry Punch, Australian firm Dr. Red Nutraceuticals, but the researchers say the experiments were designed and conducted independently in the University of Sydney. Meanwhile, at the same event, researchers from Rutgers University presented a study they performed using a standardized green tea polyphenol they said was able to prevent the growth of colorectal tumors in a rat model of human colorectal cancer. "Our findings show that rats fed a diet containing polyphenon E, a standardized green tea polyphenol preparation, are less than half as likely to develop colon cancer,"​ said Hang Xiao, research associate at the Department of Chemical Biology in Ernest Mario School of Pharmacy at Rutgers. According to Xiao, the results are consistent with previously published results conducted under the same project - though led by professor C.S. Yang - which showed green tea consumption was associated with lower colon cancer rates in Shanghai, China. "When you account for caloric consumption, 0.24 percent polyphenon E in the diet gave the experimental rats the equivalent of about four to six cups of tea a day,"​ said Xiao. "While I can't make any recommendations for how much green tea people should drink each day, it isn't uncommon for some to drink that much tea." ​ For the study, the researchers split the rats into two groups each fed a high fat diet designed to closely resemble a Western diet. Half of the rats received a 0.24 percent solution of the green tea extract polyphenon E, of which the main active ingredient was said to be EGCG. Following a 34-week period, the rats that had received polyphenon E developed 55 percent fewer tumors compared to the control rats and their tumors were 45 percent smaller. The researchers detected green tea polyphenols in the blood plasma as well as the colorectal mucosa of the rats that had received the extract. In addition, those rats given the extract weighed about five percent less than the control group, possibly because green tea polyphenols have the potential to block lipid absorption in the body.