Protease Enzyme Therapy for Cancer and Papaya Leaf

Scientists continue to work to define the reason why proteases like the ones in papaya leaf (papain and chymopapain) have shown to slow the growth of tumors.

“…we have discovered that proenzyme therapy, mandated first by John Beard nearly one hundred years ago, shows remarkable selective effects that result in growth inhibition of tumor cells with metastatic potential.”

-Proenzyme therapy of cancer. Novak JF, et al. Anticancer Res. 2005 Mar-Apr.

John Beard, a Scottish doctor, proved the effect of trypsin (a protease taken from a young cow) on halting the growth of tumors in humans by injecting part of the Pancreas of the young cow straight into human tumors.

Papain has been shown to be more powerful of a protease than trypsin.

Pill with Papaya Leaf Extract Intended to Fight Dengue

There are a number of positive results from various clinical studies on the effect of papaya leaf juice on Dengue Fever:






6. Review of seven clinical studies


And now a clinical study on Microlab’s nutraceutical pill, Caripill:

Click to access japi.pdf

The Julia Ruffin Project promotes papaya leaf for its effect on disease.

Papaya Leaf Has The Caffeic Acid That Battles Prostate and Breast Cancer

Of the list of cancer-fighting phytochemicals found in papaya leaf, Caffeic Acid has been shown as the most abundant of any in the papaya leaf, and significantly more abundant in the leaf than in any other part of the papaya plant including the fruit.

-Proximate Analysis, Antioxidant and Anti Proliferative Activities of Different Parts of Carica papaya Maisarah AM1, Asmah R1 and Fauziah O2, 1Department of Nutrition and Dietetics, Universiti Putra Malaysia, Malaysia 2Department of Human Anatomy, Universiti Putra Malaysia, Malaysia

What is significant about this is that Caffeic acid has shown effect on fighting specifically Prostate and Breast cancer. Its use is also as a complement to standard drugs like Tamoxifen. See the selected studies below.

Prostate Cancer:

Click to access 2064-2068.pdf

Click to access documento-23.pdf

Breast Cancer:

2016 Study on Fermented Papaya in form of FPP Indicates Cancer Effect

FPP is a registered trademark for a natural preparation of fermented green papaya that has been under intense study for years related to its effect on cancer and viruses.

The study below, published this year by the Asian Pacific Journal of Cancer Prevention, discusses the amazing effect of fermented papaya taken orally, on tumors.

The fermenting of papaya leaf is part of the ancient Aryuvetic medicine. The papaya leaf has some similar enzymes that may account for the medicinal-related properties also found in the green, unripe papaya used as the base for FPP. Fermented products have shown to be more easily absorbed by the body.

Anti-Tumor and Immunoregulatory Effects of Fermented Papaya Preparation (FPP: SAIDO-PS501)

Shinki Murakami1*, Shingo Eikawa2, Savas Kaya2, Mitsuko Imao1, Toshiki Aji2

 Asian Pac J Cancer Prev, 17 (7), 3077-3084

Papaya Leaf: Super Anti-Oxidant

Scientists have shown the anti-oxidant potential of papaya leaf by comparing the effect of alpha-tocopherol in the lab.

Alpha-tocopherol is a form of Vitamin E. According to the Health Information Fact Sheet of the National Institute of Health, 
“…Vitamin E is a fat-soluble antioxidant that stops the production of ROS formed when fat undergoes oxidation. Scientists are investigating whether, by limiting free-radical production and possibly through other mechanisms, vitamin E might help prevent or delay the chronic diseases associated with free radicals.”

A summary of the study:

“This preliminary study indicates the safety and antioxidative stress potential of the juice of C. papaya, which was found to be comparable to the standard antioxidant compound alpha-tocopherol.”

-Mehdipour, S., Yasa, N., Dehghan, G., Khorasani, R., Mohammadirad, A., Rahimi, R. and Abdollahi, M. (2006), Antioxidant potentials of Iranian Carica papaya juice in vitro and in vivo are comparable to α-tocopherol. Phytother. Res., 20: 591–594. doi:10.1002/ptr.1932

Scientists published papaya leaf tea as invention to combat cancer

Filed in 2005 by Nam Dang and Chikao Morimoto to the US Patent Office, the portion of the application below offers a view from the scientists as to the way to brew and take the tea for effect on more than ten types of cancer. 

The indication from the application looks like it is “preferable” to take one half to three cups per day of papaya leaf tea, approximately, for one to three months to combat the listed cancers.

…”The present invention’s brew/extract components, prepared from, for example, a papaya leaf, or fractionated components thereof, are effective in the prevention or treatment of stomach cancer, lung cancer, pancreatic cancer, liver cancer, colon cancer, uterine cancer, ovarian cancer, neuroblastoma or other solid cancers, or lymphoma, leukemia or other blood cancers. In a preferred embodiment, treatment is administered to those suffering from a disease. In another embodiment, treatment is administered as prophylaxis. The dose of the brew/extract components or fractionated components thereof to be administered will depend on the dosage form, symptoms of the subject, type of cancer or the like. However, for example, when the brew/extract is taken, it is normally preferable to take an amount of 100 ml to 750 ml per day, every day for between one month and three months. When the fractionated components are taken, it is preferable to take an amount of 10 ml to 200 ml per day, every day for between one month and three months.”

Section [0011]

Compositions for Cancer Prevention, Treatment, or Amelioration Comprising Papaya Extract 

US 20080069907 A1

The scientists, along with Noriko Otsuki, also published in the Journal of Ethnopharmocology the following study in 2010, “Aqueous extract of Carica papaya leaves exhibits anti-tumor activity and immunomodulatory effects” which revealed in detail their science behind the tea.

This article is not intended to prescribe the tea, only to publish information related that is available by academics who study papaya leaf.

Papaya Leaf for the Natural and Affordable War on TB

A recent article in Aljazeera documents the desperate poverty, a shortage of funding for TB medication, and developing resistance to TB drugs in Madagascar.

Madagascar: The vulnerability to tuberculosis

New research in India has shown the potential of papaya leaf for its effect on TB.

“…By using alamar blue dye assay and in-vitro bioassay based on inactivation of viability by a procedure similar to neutralization test were used to study the inhibition of Mycobacterium tuberculosis which shows anti-tb activity against clinical strains of sensitive and drug resistant Mycobacterium tuberculosis (pyrazinamide, streptomycin, ciprofloxacin). The present results are possibly one of the first few investigations showing a clear indication of the potent anti-tubercular effect of carica papaya.”

Naga Swathi Sree Kavuri, Sravani Yangalasetti, Venkata Rao Vutla. Anti-tubercular Activity of Leaf and Seed Extract of Carica papaya. Inventi Rapid: Planta Activa, 2016(1): 1-3, 2015

Papaya Leaf: Don’t Boil it. Brew it.

In a new study that investigated the effect of aboriginal methods using papaya leaf for medicinal effects, the researchers found that the traditional decoctions (boiling the leaves) had LESS effect on cancer cells than the fresh juice from the leaves. This research result is not surprising, as the enzyme papain in the leaf is most effective at 150-160 degrees F. 

The researchers also called their alternative boiling method “brewing”…as in “brewing” tea. 

Tea enthusiasts would not connect to this definition as “brewing” tea is a delicate act of boiling water, letting it cool to the proper temperature, (typically 150-160 F) then pouring over the tea. 

Related to its (papaya leaf tea) effect on cancer, I would encourage the scientists to test again a true, “classically brewed” papaya leaf against the papaya juice to find its effect on this set of cancer cells in the lab.

Again, it is glorious to see strong research indicating the selective effect of papaya leaf on SCC25 cancer cells. Exciting research. Thank you to the team in Australia!!

Traditional Aboriginal Preparation Alters the Chemical Profile of Carica papaya Leaves and Impacts on Cytotoxicity towards Human Squamous Cell Carcinoma

Feb 1, 2016

Thao T. Nguyen1, Marie-Odile Parat1, Paul N. Shaw1, Amitha K. Hewavitharana1, Mark P. Hodson1,2*
1 School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia, 2 Metabolomics Australia, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia

Click to access asset

Papaya Leaves Beat Standard Antibiotics in Lab

According to the International Journal of Herbs and Pharmocological Research:



1Orhue P.O. and *2Momoh A.R.M.

In this research where a petroleum extract of papaya leaf was compared to two common antibiotics, Perflacine and Cefuroxime on bacterial organisms S Aureus, E-Coli, and P aeruginosa, papaya leaf was found to be more powerful.

Their chart below…Orhue%20and%20Momoh.,%202(4)%202013.pdf