View Full Version : Screening of antiproliferative effect of aqueous extracts of plant foods

01-11-2010, 10:14 PM
Int J Food Sci Nutr. (javascript:AL_get(this,%20'jour',%20'Int%20J%20Fo od%20Sci%20Nutr.');) 2009 May 26:1-15. [Epub ahead of print]
Screening of antiproliferative effect of aqueous extracts of plant foods consumed in Mexico on the breast cancer cell line MCF-7.

Garcia-Solis P (http://www.ncbi.nlm.nih.gov/pubmed?term=%22Garcia-Solis%20P%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_RVAbstract), Yahia EM (http://www.ncbi.nlm.nih.gov/pubmed?term=%22Yahia%20EM%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_RVAbstract), Morales-Tlalpan V (http://www.ncbi.nlm.nih.gov/pubmed?term=%22Morales-Tlalpan%20V%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_RVAbstract), Diaz-Munoz M (http://www.ncbi.nlm.nih.gov/pubmed?term=%22Diaz-Munoz%20M%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_RVAbstract).
Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Campus UAQ-UNAM Juriquilla, Queretaro, Mexico.
We evaluated the antiproliferative effect of aqueous extracts of 14 plant foods consumed in Mexico on the breast cancer cell line MCF-7. The plant foods used were avocado, black sapote, guava, mango, prickly pear cactus stems (called nopal in Mexico, cooked and raw), papaya, pineapple, four different cultivars of prickly pear fruit, grapes and tomato. beta-Carotene, total phenolics and gallic acid contents and the antioxidant capacity, measured by the ferric reducing/antioxidant power and the 2,2-diphenyl-1,1-picrylhydrazyl radical scavenging assays, were analyzed in each aqueous extract. Only the papaya extract had a significant antiproliferative effect measured with the methylthiazolydiphenyl-tetrazolium bromide assay. We did not notice a relationship between the total phenolic content and the antioxidant capacity with antiproliferative effect. It is suggested that each extract of plant food has a unique combination of the quantity and quality of phytochemicals that could determine its biological activity. Besides, papaya represents a very interesting fruit to explore its antineoplastic activities.

PMID: 19468947 [PubMed - as supplied by publisher]

01-12-2010, 08:28 AM
Excellent. This continues to encourage the recommendations of 8-10 servings of fruits/vegetables a day with a variety of colors. Food synergy is an often under-rated phenomenon.

01-21-2010, 08:29 PM
Ummm...careful with the fruits..lotsa glucose in there.

01-24-2010, 12:22 AM

I think they are fructose - different from glucose.

01-24-2010, 12:35 AM
Ok...same glycemic issue.

01-24-2010, 01:03 AM
In Taiwan (as well as in China), I've seen people use papaya as a meat tenderizer. My Mother would put a slice of papaya into the pot when she's cooking 'tough' meat such as beef cubes or pork roast.

I learned about the difference between fructose and glucose from observing my late Mother-in-law. She had been a diabetic for over 20 years and was encouraged by her doctor to eat fruit whenever she had a craving for sweet stuff.

"Glycemic index has been advocated as a means to gauge the compatibility of foods with the special diet needs of people with diabetes (http://her2support.org/vbulletin/misinfo_about_fructose.asp). Fructose has a low glycemic index and results in moderate release of insulin to the bloodstream relative to glucose and sucrose."

Guess it's just the lesser of the two 'evils'.

01-25-2010, 12:45 PM
There is rarely a need to limit/eliminate fruit from the diet (even as a diabetic-as pointed out). In fact, eliminating fruit from the diet places one at at risk for missing some of the key cancer fighting nutrients provided by this group. While it is true that the intake of fruit does cause an increase in blood sugar it is no more so than whole grains or starchy vegetables like sweet potatoes. Wild fluctuations in blood sugar/insulin levels are a concern but not the normal rise and fall that results from a well balanced diet.

01-25-2010, 01:46 PM
Just going by the recommended limitation I see in Block's Life over Cancer. And the fact that advanced glioma and hormone refractory prostate cancer patients have had documented improvements on carbohydrate restricted diets (http://her2support.org/vbulletin/showthread.php?t=39588). Seems to be something to it. I wouldn't think sweet potatoes would be advisable either. Maybe not so bad if strategically combined with foods that counteract/prevent the glycemic boost and resultant insulin release. The noted monotherapy benefit of Metformin in triple negative (http://her2support.org/vbulletin/showthread.php?t=39740) makes me think that without Her2, ER or Pr, the cancer relies more heavily on glycolysis/glucose...maybe explaining the increased benefit in that group. Cancer stem cells are thought to be hypoxic and more reliant on glycolysis too...again offering a partial explanation of Metformin's benefit there. Perhaps some limitation, strategic combining and use of intelligent supplementation might make the most sense once dealing with active cancer.
Eh...food for thought.

01-25-2010, 05:53 PM

There are some places in the world where sweet patato is the major source of starch - like rice and wheat. When Taiwan was occupied by the Japanese (for 51 years before the end of WWII), rice was taken by the Japanese and transported back to Japan and many Taiwanese depended on sweet patato to survive. Many high-end restaurants in Taiwan now serve sweet patato dishes and people use phrases like 'remember the time when we were eating sweet patatoes... " I don't remember seeing anything about higher cancer rate back then. Course one has to factor in the industrialization and pollution in the later days.

I think the high fiber in sweet patato negates whatever harm its carbohydrate content might cause (fiber will make one full very quickly - less consumption and less burden on our stomach.)

The best strategy is perhaps to follow the practice of my 94-year-old Dad and 87-year-old Mom: "Eating less brings out the taste (more delicious); Overeating only brings one stomachache."

01-27-2010, 01:10 AM
Low compared to a regular potato or bread..high compared to a lot of vegetables:

In fact, high compared to pasta...a known carbo loader.

But I do find the idea of sweet potato nostalgia fun ;)

01-27-2010, 09:17 AM
This is becoming and interesting discussion. The disease “cancer” probably shouldn’t even be classified as one disease because one cancer vs. another cancer often have little in common and obviously treatments for each have massive differences. What works for one does not always work for another. Rich, you are absolutely right that the ketogenic diet has demonstrated some benefit in certain brain tumors. However, this has not been demonstrated and/or studied in brain mets from breast cancer or any other metastatic disease therefore I would caution any application of that evidence to a metastatic situation. These mutated cells have wide metabolic variations. Some may feed on glucose while others prefer free fatty acids. They body produces glucose even in the absence of carbohydrate intake. In the meantime, patients are tasked with following an extremely restrictive, unpleasant diet causing nutrient deficiencies and huge social impact.

I don’t disagree with eating foods low on the glycemic index, however, it isn’t a perfect system either. The hormonal responses to a diet high in simple sugar are associated with poorer outcomes. As a dietitian I certainly wouldn’t recommend a diet high in simple sugar anyway. With that being said, it is highly unlikely that eliminating all forms of sugar (i.e. fruit, sweet potatoes) from the diet will provide any benefit to most tumor types. In fact, the opposite is more likely and demonstrated in countless nutrition/cancer studies. Note especially the WHEL study findings that demonstrated that breast cancer survivors who ate 5-7 servings of fruits and vegetables per day and got 30 minutes of physical activity on at least 6 days of the week cut their mortality rate in half. The WINS study found that a very low fat diet cut risk of breast cancer recurrence by up to 40%. The women that followed the very low fat diet inevitably increased their fruit and vegetable intake in order to achieve satiety. The World Cancer Research Fund and AICR’s global report provides countless examples of benefit to increasing the intake of plant foods.

01-27-2010, 09:28 PM
Well...besides glycolysis, hard to find much in common between glioma and prostate cancer...two cancers with controlled studies that showed efficacy of a ketogenic diet. The mantra for years has been the endless variations in cancer. I'm sure that makes petri dish companies very happy. Personally, I'm far more excited when pan-cancer fundamentals such as glycolysis are identified and there appear to be strategies as simple as doing less of something that can help.
Actually, I didn't suggest elimination of carbs. That would be pretty extreme.
I'm not sure it makes sense to generalize in terms of "fruits and vegetables". Green beans and oranges may be a few steps from each other in the produce section but they are miles apart in terms of glycemic index. That orange is far more likely to spike the blood sugar and trigger an insulin release that would make the lowly green bean blush with inadequacy. Eating a bunch of oranges and potatoes is going to check off the fruit and veggie list as quickly as you can say diabetic. But..I don't doubt that having an overall healthy lifestyle that includes excercise helps control blood sugar, insulin and their relation to cancer. I just think those efforts can be undone by adherence to food categories while ignoring how that food gets processed.
I remember one of the quotes from a study where the researchers were excited by the great results. But they were surprised by how many folks dropped out because they wouldn't "give up the sweets".
If you have links handy for the studies you mention, post 'em.

More carb dogma here (http://her2support.org/vbulletin/showthread.php?t=39588)

01-28-2010, 06:37 AM
Here is a link to the Global Report to which I made reference. http://www.dietandcancerreport.org/ You can download a chapter at a time or purchase an entire copy. WINS and WHEL studies were both large randomized controlled studies with multiple off-shoot findings. You can search both on pubmed.com.

Sometimes email/technology does not lend itself well to getting our emotional intent across as we would desire. I certainly did not intend to sound arrogant in my recent post and apologize if it was interpreted that way.

02-01-2010, 12:25 AM
A lot of vaguely labeled links there. Post a direct link if there's one in particular. Did a search on carbohydrates and came across this one talking about importance of avoiding starchy high glycemic veggies and fruits due to elevating insuling as a cancer growth factor.:

02-03-2010, 02:05 PM
As I read this "include a variety of non-starchy vegetables and of fruit" I interpret it as avoiding starchy vegetables (corn, peas, potatoes) as the slides following recommend a variety of colors and fruits/veg that would not be low GI. Maybe we are splitting hairs here.

The following are the references for the WINS and WHEL studies to which I made reference.

Breast Cancer Res Treat. 2007 Jan;101(2):225-32. Epub 2006 Sep 21.
Correlates of physical activity level in breast cancer survivors participating
in the Women's Healthy Eating and Living (WHEL) Study.

Hong S, Bardwell WA, Natarajan L, Flatt SW, Rock CL, Newman VA, Madlensky L,
Mills PJ, Dimsdale JE, Thomson CA, Hajek RA, Chilton JA, Pierce JP.

Dietary fat reduction and breast cancer outcome: results from the Women's
Intervention Nutrition Study (WINS)
George L Blackburn and Katherine A Wang
Am. J. Clinical Nutrition, Sep 2007; 86: 878S - 881S.