I was asked by my cousin to comment about the use of soursop as an anti-cancer remedy, which is a very popular complementary and alternative medicine for cancer in Malaysia. The dry leaves of soursop are either taken in powder form or as a tea made from boiling dry soursop leaves.

I love to eat soursop fruits. I have heard of the many health claims on soursop. Besides being a cancer buster, there are also claims that it can help to lower blood sugar and improve liver detoxification. However, I have never really studied its properties and uses in herbal medicine. My cousin’s inquiry has prompted me to research into the scientific literature to learn more about this superfood acclaimed by many.

Traditional uses

The scientific name of soursop is Annona muricata. The term Annonna reminds me of how the fruit is called in the Hokkien dialect: “Ang mo nana”. Literally means “caucasian pineapple”. Originally from Central and South America. The A. muricata plant has been introduced to many tropical countries in Western Africa, South and Southeast Asia. It is called differently over the world with names such as graviola, guana´bana, huanaba, and manyothers [1].

All parts of this plant have been traditionally used in different cultures to treat various ailments. Concoctions made from leaves, barks or roots of this plant is utilized for malaria (Uganda, Togo, Cameroon,Vietnam), diabetes (Uganda), and skin ailments (Indonesia and South Pacific islands). The paste made from its leaves is a topical painkiller (Mauritius,New Guinea, Ecuador) or oral analgesic (Brazil and Mexico) [2]. In Malaysia, the crushed leaves of the tree are applied on the hair to treat lice and the juice is used for treating stomach ache and hypertension [1].These are only some examples of its numerous traditional applications. Soursop is a popular medicinal plant indeed.

Anti-cancer properties

Exploring the anti-cancer properties of soursop have become a hot topic in research in recent years. My quick search in scientific databases found as many as 7 comprehensive reviews on this topic published within the last 3 years [1–7] with 4 of them freshly minted in 2018 [1,3–5]. From the latest research, we know that the plant of soursop is rich in phytochemicals of flavonoids, isoquinoline alkaloids, and annonaceous acetogenins.There are more than 70 different acetogenins in different parts of the plant and the plant extracts have been tested to be effective against many cancers in laboratory studies using cell lines or animals. Pancreatic, colon, lung, breast, skin, and haematological (blood) cancers are among those that have been tested with positive results [5].

The extract from this plant is found to exhibit many medicinal properties as summarised below [1–7]:

• Toxic to cancer cells.
• Prevent the growth of cancer.
• Protect cells from reactive oxygen species that can damage healthy cells.
• Protect against infections from protozoal, bacteria,and virus.
• Reduce inflammation.
• Enhance the immune system.
• Lower blood glucose.
• Lower blood pressure.
• Protective of liver function.
• Fight depression.
• Reduce stress.

Surely, these are great medicinal properties useful not only for cancer but also for many other coniditions and general health.

Clinical evidence  

Before we get too carried away with thes research findings, it is important to note that there is no clinical study conducted in cancer patients yet. Laboratory results are considered preliminary and there are still much to be learned. We still do not know whether the medicinal properties can be applied to human. Hence, it is far too early to proclaim soursop to be the miracle cure for cancer as some may wish to!

So far, there are only 2 published clinical cases showing the potential use of soursop in cancer patients:

1. A Malaysian complementary medicine practitioner published a case of late-stage colon cancer which was completely reversed through natural therapies including diet, lifestyle, and nutritional supplements. 5g per day of powdered leaf and seed extracts of soursop was used as part of the treatment regimen together with curcumin, artemisinin, resveratrol, fish oil, selenium, magnesium,and vitamin E. Hence, the effectiveness of soursop extract cannot be ascertained [8].
2. A case of metastatic breast cancer (i.e. breast cancer that has spread to other parts of the body) became stable for 5 years after the patient started to take soursop (10 – 12 dry leaves boiled in water for 5 -7 minutes, 1 x 240ml glass daily). This case is reported by oncologists from a cancer centre at the University of Miami, USA. The patient had undergone many rounds of different chemo and hormonal therapies previously, but her condition continued to worsen until she started to take soursop. Although the patient was taking a chemotherapy drug (Xeloda) at the same time, the oncologists were convinced that soursop did play a role in stabilizing the condition since patients on Xeloda typically survived only a few months [9].

Such cases show the promising use of soursop to support cancer treatment. However, without evidence from good quality randomized control trials, it is still too early to expect it to be used in medical treatment.

Conclusion

The plant of soursop has been used as traditional remedies in many cultures all over the world. Current research clearly indicates its potential use in cancer treatment. However, without any human study being done to confirm its efficacy, soursop will remain a folk remedy for cancer support. Don’t expect your doctor to endorse it.   

References

[1]        A. V. Coria-Téllez, E. Montalvo-Gónzalez, E.M. Yahia, E.N. Obledo-Vázquez, Annona muricata: A comprehensive review on its traditional medicinal uses, phytochemicals, pharmacological activities, mechanisms of action and toxicity, Arab. J. Chem. 11 (2018) 662–691. doi:10.1016/j.arabjc.2016.01.004.

[2]        Y. Gavamukulya, F. Wamunyokoli, H.A. El-Shemy, Annona muricata: Is the natural therapy to most disease conditions including cancer growing in our backyard? A systematic review of its research history and future prospects, Asian Pac. J. Trop. Med. 10 (2017) 835–848. doi:10.1016/j.apjtm.2017.08.009.

[3]        A.I. Yajid, H.S. Ab Rahman, M.W. Pak Kai, W.Z. Wan Zain, Potential Benefits of Annona muricata in Combating Cancer: A Review, Malaysian J. Med. Sci. 25 (2018) 5–15. doi:10.21315/mjms2018.25.1.2.

[4]        S.M.A. Wahab, I. Jantan, M.A. Haque, L. Arshad, Exploring the leaves of Annona muricata L. as a source of potential anti-inflammatory and anticancer agents, Front. Pharmacol. 9 (2018) 1–20. doi:10.3389/fphar.2018.00661.

[5]        A.K. Qazi, J.A. Siddiqui, R. Jahan, S. Chaudhary, L.A. Walker, Z. Sayed, D.T. Jones, S.K. Batra, M.A. Macha, Emerging therapeutic potential of graviola and its constituents in cancers, Carcinogenesis. 39 (2018) 522–533. doi:10.1093/carcin/bgy024.

[6]        S.Z. Moghadamtousi, M. Fadaeinasab, S. Nikzad, G. Mohan, H.M. Ali, H.A. Kadir, Annona muricata (Annonaceae): A review of its traditional uses, isolated acetogenins and biological activities, Int. J. Mol. Sci. 16 (2015) 15625–15658. doi:10.3390/ijms160715625.

[7]        P. Ioannis, S. Anastasis, Y. Andreas, Graviola: A Systematic Review on Its Anticancer Properties, Am. J. Cancer Prev. 3 (2015) 128–131. doi:10.12691/AJCP-3-6-5.

[8]        S. Yap, Colon cancer reversed by phyto-nutritional therapy: a case study, Int. J. Biotechnol. Wellness Ind. 2 (2013) 132–139. http://search.proquest.com/openview/5f52a5711f349143ccf68e39e1eb45d1/1?pq-origsite=gscholar&cbl=2032181.

[9]        D.M. Hansra, O. Silva, A. Mehta, E. Ahn, Patient with Metastatic Breast Cancer Achieves Stable Disease for 5 Years on Graviola and Xeloda after Progressing on Multiple Lines of Therapy, Adv. Breast Cancer Res. 03 (2014) 84–87. doi:10.4236/abcr.2014.33012.