Your browser version is outdated. We recommend that you update your browser to the latest version.

Käännä tämä sivu - Google konekäännös suomeksi


 How Paw Paw Works Against Cancer Cells

In order to understand how paw paw works, it is helpful to be familiar with a little biology on human cells. It is also recommended that you watch the video animation on paw paw if you have not already done so. It may take a couple of times watching it to catch everything, but it should help your comprehension of the material.

Simple Cell Biology and ATP Production

Simply put, cells need energy to live, survive, and multiply--no real surprise. After all, we know that we must give our bodies energy in the form of food in order to live. During the digestion process, the food begins to be broken down and put into a form that eventually can be utilized by the cells in our body. One result of this process is the formation of blood sugar, or glucose. As blood travels throughout the body, the cells absorb the life-sustaining glucose. All cells need it, but some need more than others and are thus "high-users."

The cell has some special molecules on its exterior that transport glucose from the blood into the cell--appropriately called "glucose transporters." However, at this point, the process is not done. The cell must then convert the glucose into usable electrons--in other words, usable energy. There are a couple of different processes that the cells use to accomplish this, but the vast majority of the metabolism (energy conversion) that takes place is through the mitochondria of the cell.

NADH and FADH2: the electron transport chain


The redox energy from NADH and FADH2 is transferred to oxygen (O2) in several steps via the electron transport chain. These energy-rich molecules are produced within the matrix via the citric acid cycle but are also produced in the cytoplasm by glycolysis.

The mitochondria resides on the interior of each cell. Actually, each cell has hundreds or thousands of them. (On the picture, the mitochondria are the "sausage-shaped" structures on the interior of the cell walls.) As noted earlier, their primary purpose is to take glucose and oxygen and use it to produce the energy that the cell needs. The energy that is produced is called adenosine tryphosphate, or ATP for short.

In general, cancer cells fit the profile of "high users" of ATP. In fact, some studies indicate that they need anywhere from 10-17 times as much ATP as a normal cell in order to survive and multiply. Thus, if the ATP that is produced by the mitochondria of the cancer cells can be somehow controlled or reduced significantly, those cells can be negatively impacted, hopefully making them die off.

 Acetogenins--the Substances that Reduce ATP

Research by Dr. Jerry McLaughlin of Purdue University found that the paw paw tree is a source of substances known as acetogenins. (Since the family Latin/scientific name of paw paw is Annonacea, these natural substances are often referred to in the literature as Annonaceous Acetogenins.) It is these acetogenins that he found to drastically reduce the ATP production of the cells' mitochondria.

There are several different acetogenins. They vary from species to species of trees within the "paw paw family", and within other related trees. However, Dr. McLaughlin found that the highest concentrations and most powerful acetogenins were in the Asimina triloba species of the paw paw. Furthermore, he found that there were even differences in the actual geographical location of the trees--noting during his research that some groves of trees were more potent than others.

Important Note: Not surprisingly, some companies have produced products using graviola (a biological cousin of the paw paw) and market them as similar to--or equal to--paw paw itself. He has written on several occasions in technical papers detailing the big difference chemically and structurally between the acetogenins found in graviola and those found in paw paw. Dr. McLaughlin developed a procedure to standardize extracts from paw paw to contain a certain known amount of acetogenins, and licensed it to a company in Utah. Thus, it is important for anyone contemplating using the paw paw treatment to be sure that a standardized extract of from the Asimina triloba tree is obtained.

Further research by Dr. McLaughlin found that although the acetogenins are found throughout the paw paw tree, fruit and seeds, the greatest concentration of them is in the twigs of the tree. Also, he found that the acetogenin levels peak during the month of May. Thus, even the time that the paw paw is harvested is drastically important. Thus, someone using the paw paw treatment needs to verify that the manufacturer harvests the twigs at the right time of the year.


 How the Acetogenins Work

When a person intakes a source of acetogenins, such as a capsule of standardized paw paw extract, the blood supply picks them up and delivers them throughout the body along with glucose. Although a slight amount of acetogenins may wind up in non-cancer cells, the resulting lowering of ATP production is not enough in most of these cells to cause any problems. The huge energy requirement of the cancerous cells tends to "hog" most of the acetogenins to those cells. Furthermore, when the acetogenins start working on the "high-usage" cancer cells, the resulting drop in ATP energy production is much greater than it would be in most normal cells. Thus, if cancer cells are present in the body, the paw paw tends to affect them, while leaving the normal cells alone.

Unlike chemotherapy, the paw paw works to "starve" the cancer cells instead of poisoning them. Thus, the action is usually slower than chemotherapy. However, the side effects are minimal, as discussed below.

The acetogenin energy-inhibiting properties work in basically four ways:

  • Acetogenins modulate/reduce the production of cellular energy (ATP), thus robbing the cancer cells of the energy it needs to survive. This is the basic process described above, and certainly one of the most important.
  • Acetogenins help modulate/reduce the growth of blood vessels near the cancerous cells. Since the cancer cells need more ATP, they need more glucose to convert into it. Thus, the body tends to grow new blood vessels to deliver the glucose. Actually, the new blood vessel growth needs ATP itself, so the ATP reduction helps reduce that growth that is necessary for cancer cell survival.
  • Acetogenins enhance the effectiveness of chemical medical treatments. It is very common to hear that cancer patients undergoing chemotherapy develop a resistance to the chemo itself, thus rendering the treatment to no effect. This is usually called Multiple-Drug Resistance (MDR). This resistance takes place because cancer cells will develop the ability to recognize and reject chemicals that it becomes familiar with. The cells will actually develop a "pumping action" to pump the chemicals back out of the cells before the chemicals have their desired effect. However, this pumping action used to reject the chemicals uses--guess what--ATP. Lowering ATP to these cells reduces their ability to pump out the chemotherapy drugs, thus making the cells susceptible to the chemotherapy treatments again. Several technical articles have been written on the effect of paw paw on MDR cells, some of which can be read on this website.
  • Acetogenins help reduce duplication of cancer cells. The DNA and RNA are "blueprints" that affect the structure and behavior of cells. However, ATP is an essential part of DNA and RNA division and reproduction. The lowered levels of ATP tend to reduce rapid cell growth.

 Using Paw Paw

(Note: If you decide that using paw paw is a course of treatment that you want to do, it is always recommended that you talk about this with your physician. As noted in our disclaimer, the owners and contributors of this website are simply documenting academic information, articles, and other sources on this website. They are not physicians and do not give medical advice. Under no conditions should you stop taking conventional treatment without the input/approval of your treating physician.)

If a person is serious about this type of treatment, only a standardized paw paw extract should be used. It is definitely best to purchase the product from a manufacturer that Dr. McLaughlin has personally worked with. Normally, a capsule is taken 3-4 times daily with some food. If swallowing is an issue, the capsules can break apart and the contents mixed into something easier to swallow. While not necessary for the action of paw paw to work, many people often use paw paw in conjunction with a beta - glucans, immune stimulating type of product. The beta-glucans are usually taken in between the times when paw paw is taken (between meals).

Side effects. Another positive thing about paw paw is the lack of side effects. At least one paper noted that paw paw was 300 times as toxic as one leading chemotherapy drug--without the side effects of hair loss and weight loss normally experienced. If the paw paw is taken on an empty stomach, the recipient might experience nausea and/or vomiting. The same is true if a person were to try to overdose on paw paw. (This natural anti-overdose mechanism is yet another positive.) On very rare occasions, a recipient might feel a temporary lowering of energy due to ATP reduction in cells throughout the body. Other than these, there are no side effects known.

Typical Duration of Use. In general, paw paw should not be used for any sustained, prolonged time unless abnormal cells are present. In the absence of cancer cells, the paw paw will be attracted to other cells in the body that are "high energy usage" cells. They could be anywhere, but the likely candidates are in the digestive and intestinal systems. Because of that, paw paw should not be used as a preventative. It is sometimes used for short durations (less than one month) internally for parasites. Thus, if a person is determined to be cancer-free, they should generally stop taking it no more than a month later. Often, the person may come back and take it for short durations (about a week) each month. However, sustained, prolonged usage is usually ended.

If a preventative is being considered, it is probably wiser to consider things that build and support the immune system, such as a beta - glucans product and a high antioxidant product. There are several good liquid antioxidants available, one of which is mangosteen juice. If you choose to go that route, consider a mangosteen juice that is high in xanthones and without any harmful preservatives.

It is these same basic mechanisms that made paw paw effective against lice, parasites, and plant pests. For more information and technical writing, we recommend that you visit our articles section.




 Paw paw

Indiana Banana
Hoosier Banana
Poor Man's Banana


Pages on our server, Purdue


Paw paw FactSHEET contributed by Desmond R. Layne


Paw paw (Asimina triloba): a "Tropical Fruit for Temperate Climates" by M. Brett Calloway. From: New Crops (Janick and Simon eds.) Wiley, New York, 1993.


Uncommon Fruits with Market Potential—Lee Reich


Paw paw from: Magness, J.R., G.M. Markle, C.C. Compton. 1971. Food and feed crops of the United States.


Nuts with Commercial Potential for America's Heartland


Paw paws Provide Potential


Growing Paw paws—Cooperative Extension Service, Purdue University, West Lafayette, Indiana. PDF version


The Paw paw Regional Variety Trial—Kirk W. Pomper, Desmond R. Layne, and R. Neal Peterson


Articles on Insecticidal Acetogenins contained in Paw paw Bark:

 Evaluation of Various Parts of the Paw Paw Tree, Asimina triloba (Annonaceae), as a Commercial Source of the Pesticidal Annonaceous Acetogenins—Sunil Ratnayake, J. Kent Rupprecht, William M. Potter, and Jerry L. McLaughlin


Monthly Variations in Biological Activity of Asimina triloba—Holly. A. Johnson, J. Gordon, and Jerry .L. McLaughlin



Outside links

Kentucky State University Paw paw Research Project


KSU Paw paw facebook page


PAW PAW "FRUIT FACTS" (Fruit Facts are a series of publications of the the California Rare Fruit Growers, Inc. that contain information on individual fruits, including botanical identification, description and culture notes based on California research, and characteristics of cultivars).


About Paw paws in Oregon


Fruit Explorer's MidFEx Pawpaw


The GardenWeb's page on Paw paw


Peterson Paw paws


Canada Gardens! Paw paw page



Link to information and image of Asimina tetramera (Opossum Pawpaw), a rare and endangered species from southern Florida.



Articles in other publications

Jones, S.C., R.N. Peterson, T.-A. Turner, K.W. Pomper, and D.R. Layne. 1998. Pawpaw Planting Guide Cultivars and Nursery Sources. KSU PIB 002.


Layne, D.R. and L.N. Peters. 1997. Early growth and development of pawpaw [Asimina triloba (L.) Dunal] seedlings in the greenhouse as influenced by shade and root-zone modification. HortScience 32:532 (PA).


Huang, H., D.R. Layne, and T.L. Kubisiak. 1997. Pawpaw [Asimina triloba (L.) Dunal] germplasm evaluation using RAPD markers. HortScience 32:513 (PA).


Finneseth, C.L.H., D.R. Layne and R.L. Geneve. 1997. Influence of ontological age on adventitious bud and shoot formation of pawpaw [Asimina triloba (L.) Dunal] nodal explants. HortScience 32:441 (PA).


Huang, H., D.R. Layne, and R.N. Peterson. 1997. Isozyme polymorphisms for identification and assessment of genetic variation in cultivated pawpaws [Asimina triloba (L.) Dunal]. J. Amer. Soc. Hort. Sci. 122(4):504-511. (RJA).


Layne, D.R. 1997. The influence of shade and root-zone modification on early growth and development of pawpaw [Asimina triloba (L.) Dunal] seedlings grown in the greenhouse. Trans. KY. Acad. Sci. 58(1):37. (PA).


Huang, H. and D.R. Layne. 1997. Geographic differentiation and allozyme variation in pawpaw [Asimina triloba (L.) Dunal]. Trans. KY. Acad. Sci. 58(1):37. (PA).


Finneseth, C.L.H., D.R. Layne and R.L. Geneve. 1997. Pawpaw [Asimina triloba (L.) Dunal] morphological development during seed germination and seedling emergence. Trans. KY. Acad. Sci. 58(1):37-38. (PA).


Layne, D.R. 1997. Pawpaws, p. 403-404. In: The Brooks and Olmo Register of Fruit and Nut Varieties, Third Edition, A.S.H.S. Press, Alexandria, VA (BC).


S.C. Jones and D.R. Layne. 1997. Cooking with pawpaws. KSU Pawpaw Ext. Bull.-001. 12 p. (EA).


Finneseth, C.L.H., D.R. Layne, and R.L. Geneve. 1996. Germination and seedling emergence in pawpaw [Asimina triloba (L.) Dunal]. Proc. So. Nurs. Assoc. Conf. 41:61-64. (NCP).


Layne, D.R. 1996. Development of pawpaw as a new fruit crop: research update from KSU. Pomona: 29(4):37-47. (NPA).


Layne, D.R. and R.N. Peterson. 1996. The pawpaw regional variety trial (RVT): Background, rationale and early data. HortScience 31:667 (PA).


Finneseth, C.L.H., D.R. Layne, and R.L. Geneve. 1996. Morphological development of pawpaw [Asimina triloba (L.) Dunal] during seed germination and seedling emergence. HortScience 31:633 (PA).


Huang, H. and D.R. Layne. 1996. Allozyme variation and geographic differentiation in pawpaw [Asimina triloba (L.) Dunal]. HortScience 31:592 (PA).


Layne, D.R. 1996. The Pawpaw [Asimina triloba (L.) Dunal]: A new fruit crop for Kentucky and the United States. HortScience 31:777-784 (RCP).


Polomski, R. and D.R. Layne. 1996. Pawpaws: A potential new fruit crop. American Small Farm Magazine: 5(7):27-28. (NPA).


Layne, D.R. 1996. The pawpaw: promising future for an American tree crop. The Temperate Agroforester 4(3):4-6. (NPA).


Layne, D.R. 1996. The all-American pawpaw. Part 2: Research, cultivation, and the future. The Fruit Gardener magazine, July/August Issue p. 6-9, 26. (NPA).


Layne, D.R. 1996. The all-American pawpaw. Part 1: Revival efforts may bear much 'fruit'. The Fruit Gardener magazine, May/June Issue Cover photo and article on p.12-14. (NPA).


Layne, D.R. 1996. Domestication of the pawpaw or 'Kentucky Banana'. The Green Thumb, University of Kentucky Cooperative Extension Service Publication, March-April Issue, p.12-17 (EA).


Layne, D.R. 1996. Pawpaw research at Kentucky State University: An update. Trans. KY. Acad. Sci. 57:49-50 (PA).


Layne, D.R. 1995. NewCrops FactSheet: Pawpaw, 6p. NewCROP New Crop Resource Online Program, Indiana Center for New Crops and Plant Products, Purdue University. WWW url address:


Layne, D.R. and M.G. Kwantes. 1995. Growth enhancement of pawpaw [Asimina triloba (L.) Dunal] seedlings as influenced by root-zone temperature and fertilization regime. Proc. 3rd Nat. Symp. New Crops: New Opportunities, New Technologies. Oct. 22-25, 1995, Indianapolis, IN, p.93 (PA).


Layne, D.R. and M.G. Kwantes. 1995. The influence of root-zone temperature and fertilization regime on early growth and development of pawpaw (Asimina triloba Dunal) seedlings. HortScience 30(4):870 (PA).


Jones, L., D.R. Layne, and M.G. Kwantes. 1995. Pawpaw (Asimina triloba) seedling growth and development: Influence of incident light intensity and fertilization regime. HortScience 30:437 (PA).


Jones, L., D.R. Layne, and M.G. Kwantes. 1995. Influence of incident light intensity and fertilization on growth and development of pawpaw [Asimina triloba (L.) Dunal] seedlings. Trans. KY. Acad. Sci. 56:81-82 (PA).


Layne, D.R. 1994. The horticulture research program at Kentucky State University: An introduction. Trans. KY. Acad. Sci. 55:78-79 (PA).

Publication Classification Code:
BC=Book Chapter; RJA=Referreed Journal Article; RCP=Refereed Conference Proceedings; NCP=Nonrefereed Conference Proceedings; NPA=Nonrefereed Popular Article; EA=Extension Article; OLP=On-line Publication; PA=Published Abstract.

Popular Press

I. International

"Pawpaw Article". Popular Science Magazine, August 1997 Issue, in press.

"Grow grow pawpaw!". Organic Gardening Magazine, "New Ground" Section, February 1997 Issue, pgs. 19-20.

Pawpaw interview with Charlie Murphy, ABC World News Tonight with Peter Jennings, Program aired Oct. 3, 1996.

"Tropical try-out: The pawpaw adventure starts here - a 'hardy' tropical tree for the temperate zone." New, Rare and Unusual Plants, October 1996 Issue, Vol. 2(3):97,106.

Radio interview about pawpaws with Noah Adams for "All Things Considered" daily evening news program on National Public Radio, program aired 5:50 pm Dec. 5, 1995.

"Neal Peterson's goal is to domesticate the wild pawpaw", The Wall Street Journal, Cover story, Nov. 18, 1993.


II. National

"Pawpaw article". Garden Design magazine, "Growing" section, August/September 1997 issue (in preparation).


"The Return of the Pawpaw", Better Homes and Gardens On-Line, Gardening Section. Located at WWW url address:

"Book Reviews: Cooking with Pawpaws". Fruit Gardener magazine, May/June 1997 Vol. 29, No. 3 Issue, p.26.

"Pawpaws making a comeback". Agricultural Research magazine, USDA-ARS, March 1997 issue, p.16.

"Spotlight on pawpaw". National Gardening Magazine, "What's News" Column, p. 19, Oct. 1996 Issue.

"Pawpaw: A tropical tree for the temperate zone", The Cyber-Plantsman (an on-line magazine 'for the serious gardener'). WWW url address: April 26, 1996.

"Way down yonder in the pawpaw patch", Country America magazine - September 1995 Issue, p.78.

"The pawpaw paradox", American Horticulturist, February 1995 Issue, pgs. 28-33.


III. Regional

"Exotic fruit: Pawpaw is part of America's past, and perhaps, future", Chicago Tribune, Chicago, IL, Good Eating Section 7:8; October 9, 1996.

Pawpaw TV interview with Vince Vermeulen, WDRB Channel 41 (FOX), Louisville, KY, 10:00 pm evening news broadcast, Program aired Oct. 6, 1996.

Pawpaw TV interview with Greg Stotelmyer, Part II. WTVQ Channel 36 (ABC), Lexington, KY, 6:00 pm evening news broadcast, Program aired Sept. 16, 1996.

Pawpaw TV interview with Greg Stotelmyer, Part I. WTVQ Channel 36 (ABC), Lexington, KY, 6:00 pm evening news broadcast, Program aired August 5, 1996.

"The Pawpaw Project", Lexington Herald-Leader, Lexington, KY, Front Page story, Section A:1, October 24, 1995.

"The prince of the pawpaw", Detroit Free Press, Detroit, MI, Section C:1, Oct. 5, 1993.

"Pawpaws are ripe for return to glory", Baltimore Sun, Baltimore, MD, Section B:1, Sept. 21, 1993.


IV. Local

"Pawpaw custard is best in the fall of the year", Appalachian News-Express, Pikeville, KY, Images Section C:1-2; October 16, 1996.

"Way down yonder in the pawpaw patch", Intelligencer Journal, Lancaster, PA, Food Section C1&3, October 2, 1996.

"Fruit may have potential as crop, cancer fighter". Times-Mail, Bedford, IN, Section A1 & A8, August 26, 1996.

"Give pawpaws a chance: A handy guide". The Charleston Gazette, Section 1E & 2E, Charleston, WV, July 21, 1996. Also appearing at WWW url address at

"Pawpaw: The fruit tree of the future". The Floyd County Times, Prestonsburg, KY, Up a Tree Section, June 5, 1996.

"Pawpaw tree discussed at PCC", The Weekly Progress, Prestonsburg, KY, Section B:7; May 29, 1996.

"Pawpaw tree expert to speak at PCC", The Weekly Progress, Prestonsburg, KY, Section B:6; April 24, 1996.

"Interest sparks for pawpaws as 'top banana' in landscaping, research", The Sentinel News, Shelbyville, KY, Section B:3, Apr. 19, 1996.

Feature Scope: Q & A with Dr. Desmond R. Layne, Pawpaw Researcher, The State Journal, Frankfort, KY, Section E:1,4, Feb. 25, 1996.

"Native fruit brings national attention to KSU researchers", News From KSU (Supplement to The State Journal, Frankfort, KY), February 20, 1996, p.3.

"KSU's work with paw paws topic of Audubon program", The State Journal, Frankfort, KY, Section C:3, Nov. 26, 1995.

"KSU receives 16 grants", News From KSU (Supplement to The State Journal, Frankfort, KY), November 1995, p.2.

"The finer points of pawpaws", The Thorobred News (Kentucky State University newspaper, November 1, 1995, p.1, 11.

"College to grow, study unusual fruit", Kentucky New Era, Section C:6, October 26, 1995.

"University to grow and study pawpaw plants", Corbin Times Tribune, Corbin, KY, Oct. 25, 1995, p.3.

"Pickin' Up Pawpaw's", Journal and Courier, Lafayette-West Lafayette, IN. Section B1: March 13, 1995.

 "Going bananas: Love it or hate it, pawpaw's one 'sexy species'", The Windsor Star, Windsor, Ont., Canada, Section A:3, Oct. 20, 1994.

 Pawpaw breeders hope native fruit can be improved", The State Journal, Frankfort, KY, Section A:10, Oct. 8, 1993.



Cookie politiikka?

Tama sivusto kayttaa cookieita tunnistaakseen käyttäjät.

Hyvaksytko cookiet?

Ostoskori 0tuotteet