Papaya Leaf Slows Free Radical Destruction that Causes Aging and Cancer

We have published research articles that show the healing effect of papaya leaf on the liver. But this study explains how this action also has anti-aging and anti-cancer effects:

From the International Journal of Pharmacy

“…In general up on entry of any foreign particle enters in to our body. Free radicals can be generated, which is based on the size of the foreign particle or physico chemical characteristics of that foreign particle (1). The free radicals are not inactivated; their chemical reactivity can damage all cellular macromolecules including proteins, carbohydrates, lipids and nucleic acids. Their destructive effect on protein may play a role in the causation of diseases, like cataracts. Free radical damage to DNA is also implicated in the causation of cancer and its effect on LDL cholesterol is very likely responsible for heart disease. Free radicals are also responsible for ageing (2).
Iron over load causes liver toxicity by producing hydroxyl radicals by promoting Fenton reaction(3). Free radicals also can be able to cause various
diseases like neurodegenerative diseases (4), cardio vascular diseases (5), cancer etc. So the work started because of these serious effects up on the free radical generation, expecting that Herbal medicines have been used able to generate antioxidants, which can be provide balance between free radical generation and anti-oxidant levels or those anti-oxidants prevents the liver damage and gastric ulceration caused by free radicals….
In present study the antioxidant activity of aqueous extract of leaf of Carica papaya was found. From the study it was also found to decrease lipid peroxidation and significant increase in catalase, glutathione and protein with the aqueous extract of leaf of Carica papaya in dose dependant manner. Literature regarding phytoconstituents shows that aqueous extract of leaf of Carica papaya contains Alkaloids Carpain, Pseudo carpain, and dehydro carpaine I & II, Choline, Caproside, Vitamin C & E. Since all these constituents are found in the leaf of this plant it is possible that these constituents may be implicated in antioxidant activity of the species. Therefore, it was concluded that the aqueous extract of the leaf of Carica papaya possess antioxidant principles and has free radical scavenging activity.
The result have shown that the aqueous extract of the leaf of Carica papaya possesses antioxidant properties, supported by the decrease in lipid peroxidation and increase in the reduced glutathione and catalase activity in in vivo method. The in vivo antioxidant activities have been supported by its free radical scavenging activities in in-vitro method. Such antioxidant activity of Carica papaya might be responsible for its importance in traditional medicine for the treatment of various disorders. The present study opens many new areas of research work. This work can be continued in the future to study and confirm liver protective activity in different experimental models and also to isolate, identify, characterize and standardize the active principle(s) that are responsible for this activity.”

Balakrishna V*, Srikanth G, Ajay kumar Sarabu, Thippani Maneshwar
Department of Pharmacology, Vaageswari College of Pharamacy, Karimnagar, Andhra Pradesh, India
International Journal of Pharmacy
Journal Homepage:


Figure is [enzyme] Papain Structure (Huet J et al., 2006)

“…Phytochemicals in c. Papaya with Reported Anticancer Activities
Carica papaya contains a broad spectrum of Phytochemicals including enzymes (in the latex), Carotenoids (in fruits and seeds), alkaloids (in leaves), phenolics (in fruits, leaves, and shoots), glucosinolate (in seeds and fruits) (Krishna et al., 2008; Parle et al., 2011). Some important Phytochemicals found in C. papaya are Lycopene, Betacarotinoid, Benzylisothyocynate, Betacryptoxanthin, Benzylglucosinolate, chlorogenic acid, caffeic acid, protocatachuic acid, Quercetin, Among more than 5000 compounds from plants that have been identified to be associated with anticancer properties (Huang et al., 2009), three groups of bioactive compounds-phenolics, Carotenoids, and glucosinolate-have attracted considerable interest in anticancer studies. Pure compounds of these three groups have been extensively researched in vivo and in vitro studies on many types of cell lines for their potential effects in cancer treatment and prevention. These bio actives act via multiple mechanisms such as cancer cell signalling, proliferation, apoptosis, migration, invasion, as well as angiogenesis and carcinogen elimination (Huang et al., 2009; Zhang et al.., 2004; Thornalley et al., 2002; Nakamura et al., 2006; Wu et al., 2009; Navarro et al., 2011; Wahle et al., 2011; Soobrattee et al.., 2006; Tanaka et al., 2012; Breemen et al., 2008) to exhibit in vitro and in vivo anticancer activities.”…Krishnamurthy…Papaya…Anticancer…25-33.pdf

CIBTech Journal of Pharmaceutical Sciences ISSN: 2319–3891 (Online)
An Online International Journal Available at 2013 Vol.2 (1) January-March, pp.25-34/Sheikh and Krishnamurthy
Review Article
*Sheikh Fauziya and R Krishnamurthy
CG Bhakta Institute of Biotechnology, Uka Tarsadia University, Maliba Campus Bardoli, Dist. Surat, Gujarat, India-394350
*Author for Correspondence

Benzyl Glucosinolate, In Papaya Leaf, Shows Anti-Cancer Activity

“…benzylglucosinolate — [is] found in all parts of the plant, but highest in young leaves [of papaya plant].”, according to a Cornell University Study.

An article in the Asian Journal of Tropical Medicine, researched by a team of Chinese scientists in 2011-12, concluded the following:

“The results in this research demonstrated that BITC has better anti-proliferative activity against human lung cancer H69 cell . In the high-dose group , the inhibition rate of cell proliferation can reach more than 80%, which conformed with the result reported in the literature[6]. The result provided foundation for the further research of anti-tumor activity of BITC extract from papaya.”
Content determination of benzyl glucosinolate and anti-cancer activity of its hydrolysis product in Carica papaya L. Ze-You Li1,2,3, Yong Wang2, Wen-Tao Shen3*, Peng Zhou1,3*

Cytokines in Papaya Leaf Tell the Body about Cancer


“Fig. 1. A model of tumor-suppressing inflammation. Th1 lymphocytes and M1 macrophages are the primary sources of pro-inflammatory cytokines that also promote cancer immunosurveillance and cytotoxicity.”

Biochimica et Biophysica Acta (BBA) – Reviews on Cancer
April 2014, Vol.1845(2):182–201, doi:10.1016/j.bbcan.2014.01.004
Open Access, Creative Commons license
Tumor-induced perturbations of cytokines and immune cell networks ☆
Brett BurkholderRen-Yu HuangRuo-Pan Huang

Papaya Leaf Tea has been shown to have effect on cancer based on this signaling by cytokines.

Aqueous extract of Carica papaya leaves exhibits anti-tumor activity and immunomodulatory effects.
Otsuki N, et al. J Ethnopharmacol. 2010.

Flavonoids make Papaya Leaf Tea Safe

In 2011 Brazilian scientists wanted to show that the apparent positive effect of papaya leaf on cancers was not toxic to the body.

The study used standard methods for discovery on this subject, and in the final analysis the study showed that papaya leaf is non-toxic by these methods and also disclosed the most likely substance in the papaya leaf that is responsible: it is the flavonoid in the leaf called rutin.

“…The results of this study indicated that an aqueous solution of the ethanolic extract of leaves of C. papaya, under the experimental conditions used, has low toxicity and an antimutagenic effect; flavonoids, such as rutin, may be the substances involved in this action.”

Antimutagenic activity of Carica papaya L. assayed in vivo by micronucleus test
Kalil, I.C.1; Gibson, B.A.V.1; Ribeiro, C.A.1; Benincá, L.S.1; Brasil, G.A.1; Andrade, T.U.1; Batitucci, M.C.P.2; Endringer, D.C.1*
1 Curso de Farmácia, Universidade Vila Velha – UVV 2 Universidade Federal do Espírito Santo – UFES
Recebido 22/09/2011 / Aceito 17/11/2011

International Journal of Herbal Medicine Documents Cancer Inhibition of Papaya Leaf

From Research Collected at the Bhupal’s Noble Institutes of Pharmaceutical Sciences in India’s largest state:

Carica papaya Linn: An Overview

Vijay Yogiraj, Pradeep Kumar Goyal, Chetan Singh Chauhan, Anju
Goyal, Bhupendra Vyas

February, 2015

” 5. Medicinal and Pharmacological properties of various parts of Carica papaya plant

5.1 Leaves
Papaya leaf has a numberless of benefits. In some parts of Asia, the young leaves of the papaya are steamed and eaten like spinach.
a) Dengue fever- Commencing on studies of Dr. Sanath Hettige, who conducted the research on 70 dengue fever patients, said papaya leaf juice helps increase white blood cells and platelets, normalizes clotting, and repairs the liver.
b) Cancer cell growth inhibition- Recent research on papaya leaf tea extract has demonstrated cancer cell growth inhibition. It appears to boost the production of key signaling molecules called Th1-type cytokines, which help regulate the immune system.
c) Antimalarial and antiplasmodial activity- Papaya leaves are made into tea as a treatment for malaria. Antimalarial and antiplasmodial activity has been noted in some preparations of the plant, but the mechanism is not
understood and not scientifically proven
d) Facilitate digestion- The leaves of the papaya plants
contain chemical compounds of carpain, Substance which kills microorganisms that often interfere with the digestive function.
Additional Benefits of Papaya Leaves: As an acne medicine, Increase appetite, Ease menstrual pain, Meat tenderizer, Relieve nausea.”