The graviola fruit is also known as soursop or shawshopu. It naturally grows in Central and South America and in tropical countries, and belongs to the plant family of annonaceae. In natural medicine, the leaves of the tropical graviola tree are used for a variety of diseases. These include rheumatism, diabetes, asthma, hypertension, parasites, bladder infection, bacterial and viral infections, neuralgia, asthma and cancer.

The leaves of the graviola plant are frequently used as an extract. Leaves, bark and fruits contain a natural composition of valuable plant compounds. These include flavonoids such as quercetin and rutin and acetogenins.

Researchers have placed their special attention to the so-called acetogenins. Acetogenins are plant constituents of the annona family (Annonaceae).

Graviola und Krebs

Acetogenins show strong activity against some cancer types, but also other parts of the annona plant may have cancer-inhibiting effects. Among others, human cancer cell lines were tested in vitro (in test tubes) and also in live animals (in vivo).
Human cancer cell lines can be cultured and the effect of chemotherapeutic agents and also vital substances can be examined.
Explanation Cell Cultures

All the more important in this context are large-scale human studies. Unfortunately, these are often rare in natural substances and especially in tumor diseases.

In a study from 2013, published in the journal “Cancer Letters” the effect of graviola was investigated in pancreatic tumors.
Graviola and Pancreatic Cancer
Graviola leaf extract caused a reduction of tumor mass and metastasis in vitro (in a test tube) and in vivo (in animals) in pancreatic carcinoma. It resulted in the inhibition of signaling pathways that regulate tumor metabolism, cell cycle, survival and metastasis.

One the acting mechanisms are the inhibiting effect of graviola on energy production in cancer cells.
Following is a summary of the publication in the “Journal of Natural Products” from 2007 by McLaughlin et al:
Acetogenins’ Effect on Cancer

A study carried out in 2013, published in the journal Current Topics in Medicinal Chemistry showed a strong effect of graviola leaves extract against “HeLa” (cervical cancer cells) and prostate cancer cell lines. Cell growth of “HeLa cell lines” was inhibited by graviola leaf extract by 80 %!
Graviola and Cervical Cancer (Cervix Carcinoma)

Another study carried out in 2011, published in the journal Nutrition and Cancer came to the conclusion that graviola fruit extract may have a protective effect against breast cancer with an EGFR overproduction. EGFR (epidermal growth factor receptor) is a cancer gene which is frequently overexpressed in breast cancer. Overexpression is often linked with a poor prognosis and resistance to chemotherapy.
Graviola in Breast Cancer

A study in 1996, published in the journal Natural Products examined the effect of graviola in colorectal cancer (adenocarcinoma).Graviola in Colorectal Cancer
In a test tube experiment, the acetogenin Cis annonacine, a plant constituent of the annona plant, showed a 10,000 times stronger effect against colon cancer cells (adenocarcinoma) than the chemotherapeutic agent adriamycin.
Further infomation about acetogenin you may find under
Acetogenin as an Active Agent

In this context, it is important to point out that only diseased tissue such as the tumor and metastases are attacked, and that healthy tissue is not damaged. There are strong indications that this is the case with acetogenins of the graviola plant. Some studies also speak of a strong selective toxicity against degenerated cells of various cancer cell lines.

A selective toxicity even against medicines (chemotherapeutic agents) for multi-resistant cancer cell lines was described in the journal Cancer Letters. Investigated were resistant cells, for example, resistance against adriamycin and doxorubicin.
Acetogenin is Highly Targeted against Cancer Cells
An article in the journal Oncology Research also describes this fact. Graviola and Acetogenin

The fruit extract also exhibits selective toxicity in human breast cancer cells in vitro (in a test tube) and in vivo (in animals).
Graviola and Breast Cancer

However, there are also critical opinions.
In animals, a harmful effect was showed with too high acetogenin concentration. However, there may be a future use of graviola in prostate cancer.
Side Effects of Graviola

A study in 2007 suspects that graviola seeds (acetogenins and alkaloids) may have nerve-damaging (neurotoxic) effects and cause the so-called tauopathy. A news article of the Marburg University states that a neurodegenerative disease, only present on the Caribbean island of Guadeloupe was investigated, and probably could be related to the consumption of annonacin and acetogenin containing plants. It is indicated that the so-called tauopathy is associated with a pathological accumulation of tau protein in the brain. Tauopathy by plant-based neurotoxin: Junior Award for Marburg doctorial student.
Graviola – Acetogenin and Side Effects (Tauopathy)

French researchers investigated this suspect. However, they were unable to confirm that graviola causes the Parkinson-like neurological symptoms.

However, they pointed out that further studies are needed to properly assess a neurological risk of potentially nerve-damaging ingredients. Also the necessity for precise doses and mixing ratios is indicated.
“Avis de l’Agence française de sécurité sanitaire des aliments relatif aux risques à la consommation de liés Corossol et de ses Préparations”
Acetogenin Tauopathy Official Investigation

Graviola and Parasites

Moreover, the seeds have an antiparasitic effect, among others, on the larvae of yellow fever mosquitoes (dengue fever).
The addition of black pepper (Piper nigrum) resulted in synergism with Graviola and enhanced its effect.
Graviola and Dengue Fever

Graviola and Diabetes

The graviola plant also seems to impact diabetes positively.
In diabetic animals the leaf extract showed regeneration of insulin-producing islet cells in the pancreas. In humans with type II diabetes, a successive decline of islet cells in the pancreas ultimately leads to having to inject insulin.
To stop the destruction of the insulin-producing cells is a treatment which tackles the origin of the disease.
Graviola – Effect on IsletCcells
Graviola and Diabetes

Graviola and Gastric Mucosa

Another study showed the gastric protective effect of the plant in animals.

A significant increase of the nitric oxide level in the stomach was observed. This is conducive to the gastric mucosa. Nitric oxide promotes (NO) among other things the blood flow in the stomach, which reduces gastric mucosal lesions.
Intact nitric oxide (NO) also inhibits the inflammatory cascade in the body. “Impaired NO” peroxynitrite causes “nitrosative stress”.
Graviola, NO and Inflammation

Intact NO is also needed for blood pressure control and defending the body against pathogens. Interestingly, in folk medicine graviola is used against blood pressure problems and against bacteria, viruses and parasites. The aggressive nitrogen radical peroxynitrite promotes inflammation. With an intact NO, the reactive oxygen species superoxide forms increased peroxynitrite. ROS and thus superoxide are increasingly incapacitated by graviola. This leads to a significant increase of the antioxidant activity (capacity) which also has an effect on maintaining an intact mucosal barrier.

Malondialdehyde is an important marker for oxidative damage to cell walls (lipid peroxidation). With graviola extract, this marker used as an indication of damaged cell wall components, could be reduced in animals.

The antioxidant enzymes catalase, superoxide dismutase (SOD) and the antioxidant glutathione, which deactivate so-called reactive oxygen species (ROS), showed an increased activity or were present in higher amounts by intake of graviola.
“Hsp 70” a so-called heat shock protein is “upregulated” genetically by graviola. On the other hand, the important “Bax apoptosis gene” is “downregulated” genetically. These two effects lead to prohibition of mucosal injury in the stomach, thus preventing stomach ulcers.
Graviola in Stomach Ulcers

The effects of graviola are diverse and promising. As mentioned, in particular the described effects in tumor diseases are based on studies of cancer cell lines and applications in animals. The concomitant use in these cases should always be discussed with a therapist.