They are known for their succulent white endocarp. They are replete in southern Nigeria. The fruit-pulp is soft with an agreeably sour flavour. It is usually eaten raw but unfortunately contains a quantity of fibre. It may be more acceptable after some preparation, that is either as juice, ice-cream, jellies but not jams. Commonly called Soursop, Annona muricata is a plant, which belongs to the family Anonaceae. H. M. Burkill in the Useful Plants of West Tropical Africa described the Soursop plant as “a small tree attaining a height of about eight metre. A native of tropical America, but now widespread in the tropics. The trunk and timber do not appear to have any particular uses.”
Soursop is a medicinal plant that has been used as a natural remedy for a variety of illnesses. Several studies by different researchers demonstrated that the bark as well as the leaves has anti-hypertensive, vasodilator, anti-spasmodic (smooth muscle relaxant) and cardio depressant (slowing of heart rate) activities in animals.
Researchers had re-verified Soursop leaf’s hypotensive (reduce blood pressure) properties in rats. Other properties and actions of Soursop documented by traditional uses include its use as anti-cancerous, anti-diabetes, anti-bacterial, anti-fungal, anti-malarial, anti-mutagenic (cellular protector), emetic (induce vomiting), anti-convulsant, sedative (induces sleep), insecticidal and uterine stimulant (helps in childbirth). It is also believed to be a digestive stimulant, antiviral, cardio tonic (tones, balances and strengthens the heart), febrifuge (cures fever), nerviness (balances/calms the nerves), vermifuge (expels worms), pediculocide (kills lice) and as an analgesic (pain-reliever).
Researchers have confirmed the anti-viral activity of ethanolic extracts of Soursop against Herpes simplex virus. Extracts of Soursop have been shown to have anti-parasitic, anti-rheumatic, astringent, anti-Ieishmanial and cytotoxic effects. Soursop has also been shown to be effective against Multi-Drug Resistant (MDR) cancer cell lines. Extracts of Soursop were also shown to be effective against the cancer cell line U973, and hematoma cell lines in-vitro. Extracts were also shown to be lethal to the fresh water mollusk, Biomphalaria glabrata, which act as a host for the parasitic worm Schistosoma mansoni. But recent studies have described how extracts of Soursop reduces blood sugar in diabetics by improving insulin production, Improves cardiovascular health by reducing blood fats, treat drug resistant cancer, stop diarrhoea in children, among others.
Nigerian researchers have evaluated the effects of methanolic extract of Soursop leaves on the pancreatic islet cells of streptozotocin induced- diabetic rats. The results of the study indicated that Soursop extract treatment decreased the blood glucose concentration of diabetic rats due to the regeneration/proliferation in the pancreatic Beta cells (Beta-cells).
The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon and somatostatin, as well as an exocrine gland, secreting pancreatic juice containng digestive enzymes that pass to the small intestine. These enzymes help in the further breakdown of the carbohydrates, protein, and fat in the chyme.
Beta cells (beta-cells, Beta-cells) are a type of cell in the pancreas in areas called the islets of Langerhans. They make up 65-80 per cent of the cells in the islets. Beta cells make and release insulin, a hormone that controls the level of glucose in the blood.
Streptozotocin (Streptozocin, STZ, Zanosar) is a naturally occurring chemical that is particularly toxic to the insulin-producing beta cells of the pancreas in mammals. It is used in medicine for treating certain cancers of the Islets of Langerhans and used in medical research to produce an animal model for Type 2 diabetes.
Streptozotocin-induced hyperglycemia in rats is considered a good model for the preliminary screening of agents active against Type 2 diabetes and is widely used. Generally, destruction of Beta-cells starts three days after STZ administration and reaches its peak at three to four weeks in rats. Streptozotocin-induced diabetes in laboratory animals has been widely used for research on diabetes and its long-term complications.
Soursop has been found to contain numerous bioactive compounds useful for the management of various ailments including Diabetes Mellitus (DM), Type 2 diabetes, in folkloric medicine. The management of DM depends on continuous hypoglycemic therapy, which may not be consistently adhere to by the patient. The researchers therefore, investigated whether or not extracts of Soursop could provide lasting hypoglycemic control through regeneration of the destroyed Beta-cells of the pancreatic islets of experimentally induced diabetic Wistar rats.