What is soursop
Soursop, also known as Graviola (family name: Annona Muricata) is a tropical and subtropical fruit, found and grown mainly in South American countries (Mexico, Brazil, Venezuela, Peru, Cuba). It can also be found in African countries and South East Asia. It comes from a broad leaf of the evergreen tree. The leaves are known as soursop leaf extract and the fruit is widely used as soursop fruit for various recipes. The soursop fruit is green with soft thorns, measures about 20-25 cm and is fleshy inside with black inedible seeds.1
Both soursop leaf extract and fruit have immense health benefits and properties. For centuries, humans have used their diet as a crucial way to treat their health, mainly through the ingestion of herbs and plants with medical properties. Recently, this has been researched further to discover the pharmacological properties of plants to understand their impact on disease.
Soursop is no exception: soursop leaves contain phytochemicals and polyphenols which can help treat cancer, diabetes, hypertension and oxidative stress.2
However it is important to note that the soursop fruit has specific maturity times and a very short window for storage. Due to its highly bioactive compounds, however, it can be used as a powder to retain its benefits and overcome the short shelf life.3
To understand the full benefits of soursop and its phytochemical constituents, we will investigate the soursop leaf, which distributes the highest amount of these properties. This is linked to the choice of soursop leaf tea in some cancer treatment options.
Health benefits of soursop
As mentioned, soursop has gained much attention in recent years due to its medicinal and pharmacological properties. It is of particular interest to study the phytochemical properties of the soursop leaf extract, and the polyphenol composition. Phytochemicals are chemicals found in plants that have antiparasitic and antibacterial/antimicrobial functions that protect the plant. Polyphenols are reducing agents that contain flavonoids which act as antioxidants: they protect the cells from free radical damage and neutralize them from toxicity.4
The leaf extract has been used in many studies to understand the health benefits, with some highlighted as follows:
- Helps with arthritis and is anti-inflammatory
A study performed on rats with induced arthritis has concluded that after 14 days of injection with the plant extract, the inflammation/swelling (oedema) was significantly reduced. It was shown that the higher doses of the leaf suppressed the proinflammatory cytokines linked to arthritis and the pain it causes.5
Further studies on mice have also shown the same effects, through inhibition of chemical mediators of inflammation. As arthritis is linked to inflammation, both these studies were conclusive that the leaf extract (mixed with ethanol) contributed to a great reduction of proinflammatory factors.6
- Reduces blood sugar and cholesterol
Further benefits of the soursop leaf have been demonstrated when studying hyperglycemia, which is the fluctuation of insulin in the blood that can lead to diabetes. This is usually caused by a spike of glucose in the bloodstream, coming from the breakdown of foods by the enzymes amylase and glucosidase. Soursop extract has shown that its phenolic activity has an inhibitory action of these enzymes, preventing a spike of glucose from the breakdown activity of these enzymes, thus reducing blood sugar. This was especially observed after eating a meal.7
The phenolic activity of soursop means the flavonoids and alkaloids components also act to reduce blood lipid levels and cholesterol. This is particularly effective when boiling the leaves to make a soursop leaf tea. Similarly to blood sugar, soursop alkaloids inhibit the fatty acid enzyme that increases blood lipid and triglyceride levels. This in return significantly lowers LDL cholesterol and saturated fatty acids.8
- Fights cancer
Compounds in soursop leaf have shown to have an inhibitory effect against breast cancer cells, prostate cancer cells, airway, liver, renal and small intestine cancers. This is due to the annonaceous acetogenins found in the leaf. Research has found that there are 34 of these in the leaf, which contribute to apoptosis of colon cancer cells and other cancer cells mentioned (death of cells).9
This apoptosis effect was further observed in studies performed in vivo, where prostate cancer cells showed signs of reduction due to a reduction in overall size of the prostate in rats after being administered with a solution of A. Muricata. Similarly, the graviola leaf has been administered to mice to highlight the protective effects of breast cancer cell proliferation (development of breast tumour, also known as carcinogenesis).10
Although the high flavonoid concentration and acetogenins contribute to effective cancer treatment, cancer research UK states that with these promising findings, it's important to note that in vitro and in vivo studies do not always translate to similar effects in humans. More research is needed to determine whether soursop has any potential benefits for cancer patients, and if so, how it should be used and in what form.
In addition, it's important to talk to a healthcare professional before using soursop or any other herbal supplement, as it may interact with medications or have other potential side effects.
- Other claimed health benefits
There is yet further cancer research to be made to prove the benefits of soursop leaf tea and other extracts for effective cancer treatment. Cancer Research UK also warns of remedies found online as an alternative to chemotherapy. Nonetheless, eating a diet rich in fruits guarantees a good intake of vitamins, which in return contributes to a healthy immune system and immune response, protects the body and fights inflammation. It is therefore important to evaluate the nutritional facts about any fruit or plant before deciding to add it routinely in a diet and also to consult a health professional before any decision.
Nutritional facts
Soursop fruit is rich in fiber and dietary vitamins: Vitamin C, B1 and B2. It is either consumed directly or mixed with other foods, such as juices and smoothies, thanks to its fleshy pulp. It contains:
16.84 g/100 g Carbohydrates, 1g/100g Protein, Fiber 3.3g/100g and total sugars 13.54g/100g 1
After water, the fruit’s second component is sugar, with 70% of the total solids. It can be taken as soursop juice, soursop leaf tea or soursop smoothie.
Soursop leaf tea mainly contains the vitamins of soursop: Vitamin C, B1/B2, Potassium, Iron and Magnesium.11
Side effects and other concerns
Side effects of soursop intake have been widely documented, and Cancer Research UK states that it can cause nerve changes and movement disorders.
A study on the effects of acetogenins and alkaloids on nerve cells has shown possible neurotoxicity, which leads to neurodegenerative diseases such as Parkinson’s.12
Another study on cervical cancer cells has also noted side effects such as metabolism disruption, nausea, vomiting, anaemia and kidney/liver complications.13
As it also reduces blood sugar and blood pressure, it can interfere with medication and cause very low levels of blood pressure in patients with underlying conditions.
It is therefore advised to consume soursop fruit and soursop leaf tea in moderation, with prior professional healthcare advice.
However the health benefits can outweigh the risks, as research looks promising and can already confirm the antioxidant and antiinflammatory properties of this wonder plant.
Summary
Soursop, also known as graviola, is a tropical fruit that grows on the Annona muricata tree.
Soursop has been studied for its potential health benefits, which include anti-inflammatory and antioxidant properties, and may help lower blood pressure, improve digestion, and boost the immune system. Some studies also suggest that soursop may have anti-cancer properties, although Cancer Research UK advises against it.
Soursop may also have some side effects, particularly when consumed in large amounts or used as a supplement. However it is an overall delicious and nutritious addition to a healthy diet when consumed in moderation. As with any food or supplement, it's important to consult with a healthcare professional before adding soursop to your routine, particularly if you have any underlying health conditions or concerns.
References
- Soursop - an overview | sciencedirect topics [Internet]. [cited 2023 Apr 4]. Available from: https://www.sciencedirect.com/topics/medicine-and-dentistry/soursop
- Moghadamtousi SZ, Fadaeinasab M, Nikzad S, Mohan G, Ali HM, Kadir HA. Annona muricata (Annonaceae): a review of its traditional uses, isolated acetogenins and biological activities. International Journal of Molecular Sciences [Internet]. 2015 Jul [cited 2023 Apr 5];16(7):15625–58. Available from: https://www.mdpi.com/1422-0067/16/7/15625
- Chang LS, Karim R, Abdulkarim SM, Ghazali HM. Production and characterization of enzyme-treated spray-dried soursop (annona muricata l.) powder. J Food Process Eng [Internet]. 2018 Aug [cited 2023 Apr 5];41(5):e12688. Available from: https://onlinelibrary.wiley.com/doi/10.1111/jfpe.12688
- https://iopscience.iop.org/article/10.1088/1742-6596/1341/3/032027/pdf
- Chan P, Ah R, Mh K, A Z. Anti-arthritic activities of Annona muricata L. leaves extract on complete Freund’s adjuvant (Cfa) – induced arthritis in rats. Planta Med [Internet]. 2010 Aug [cited 2023 Apr 5];76(12):P166. Available from: http://www.thieme-connect.de/DOI/DOI?10.1055/s-0030-1264464
- Ishola IO, Awodele O, Olusayero AM, Ochieng CO. Mechanisms of analgesic and anti-inflammatory properties of annona muricata linn. (Annonaceae)Fruit extract in rodents. Journal of Medicinal Food [Internet]. 2014 Dec [cited 2023 Apr 5];17(12):1375–82. Available from: https://www.liebertpub.com/doi/abs/10.1089/jmf.2013.0088
- Gong L, Feng D, Wang T, Ren Y, Liu Y, Wang J. Inhibitors of α‐amylase and α‐glucosidase: Potential linkage for whole cereal foods on prevention of hyperglycemia. Food Sci Nutr [Internet]. 2020 Dec [cited 2023 Apr 5];8(12):6320–37. Available from: https://onlinelibrary.wiley.com/doi/10.1002/fsn3.1987
- https://www.researchgate.net/profile/Kingsley-Agu-3/publication/342242385_Comparative_Influences_of_Extracts_of_Various_Parts_of_Annona_muricata_Soursop_on_Basal_Lipid_Profile_and_Plasma_Fatty_Acid_Synthase_in_Wistar_Rats/links/5eea2785458515814a665b08/Comparative-Influences-of-Extracts-of-Various-Parts-of-Annona-muricata-Soursop-on-Basal-Lipid-Profile-and-Plasma-Fatty-Acid-Synthase-in-Wistar-Rats.pdf
- Indrawati L, Pramono S, Ascobat P, Bela B, Abdullah M, Surono IS. Cytotoxic activity of soursop “Annona muricata” leaves extracts and their phytochemical contents. Journal of Global Pharma Technology. 2017 Feb 1;9(2):35-40.
- Moghadamtousi SZ, Fadaeinasab M, Nikzad S, Mohan G, Ali HM, Kadir HA. Annona muricata (Annonaceae): a review of its traditional uses, isolated acetogenins and biological activities. International Journal of Molecular Sciences [Internet]. 2015 Jul [cited 2023 Apr 6];16(7):15625–58. Available from: https://www.mdpi.com/1422-0067/16/7/15625
- Soursop health benefits [Internet]. Cleveland Clinic. 2021 [cited 2023 Apr 6]. Available from: https://health.clevelandclinic.org/soursop-benefits/
- Escobar-Khondiker M, Höllerhage M, Muriel MP, Champy P, Bach A, Depienne C, et al. Annonacin, a natural mitochondrial complex i inhibitor, causes tau pathology in cultured neurons. J Neurosci [Internet]. 2007 Jul 18 [cited 2023 Apr 6];27(29):7827–37. Available from: https://www.jneurosci.org/content/27/29/7827
- Qorina F, Arsianti A, Fithrotunnisa Q, Tejaputri N, Azizah N, Putrianingsih R. Cytotoxicity of soursop leaves (Annona muricata) against cervical hela cancer cells. Pharmacognosy Journal. 2020;12(1):20–4.