Cocoyam Tuber Extract Suppresses Enlarged Prostate — Experts
By Sade Oguntola
As men age, many experience prostate gland enlargement. This condition is known as benign prostatic hyperplasia (BPH) which is quite common in older men. In fact, the condition impacts about 50% of men between the ages of 51 and 60. When the prostate gets bigger, it can squeeze or partially block the urethra, which leads to problems urinating.
Now, in addition to cocoyam tubers being used as staple food, experts say that it is a potential functional food in ameliorating an enlarged prostate gland.
Currently, the treatment options for BPH include the use of drugs or surgery. Whereas the use of drugs has been associated with serious adverse effects, the use of surgery could be life-threatening, thus highlighting the need for alternatives.
Although many men with BPH have no symptoms, others show signs, most commonly, urinary and sexual difficulties. They can range from mild and barely noticeable to serious, but the amount of prostate enlargement is not directly related to the severity of the symptoms. Because BPH cannot be cured, the treatment focuses on reducing the symptoms.
The researchers investigated the effect of 50% water and ethanol extract of boiled cocoyam tuber on testosterone propionate (TP)-induced BPH rats. They assessed its effect on several parameters, including the prostate and body weights, testosterone, prostate-specific antigen (PSA) and oxidative stress.
Thirty male albino rats were randomly assigned into six groups of 5 rats each. Group 1 (negative control) received 3 mg/kg of TP and normal saline, group 2 (positive control) received 3 mg/kg of TP and 5 mg/kg of finasteride; groups 3, 4, and 6 rats received 3 mg/kg of TP and 100, 200 and 400 mg/kg of ethanol extracts of cocoyam respectively while group 5 (normal control) received olive oil and normal saline. The study lasted for 28 days.
The 2021 study in the journal, Drug and Chemical Toxicology, involved Kate Eleazu at the Ebonyi State University, Abakaliki, Ebonyi State, in collaboration with Patrick Maduabuchi Aja and Chinedum Ogbonnaya Eleazu.
The researchers said that the rats at the test dose of 2000 mg/kg during the experiment did not show any indication of gross physical or behavioural changes such as hair erection, reduction in feeding and motor activities within the 24-hour monitoring period as well as within the 14-day period.
The extract halted the breakdown of the tissue in the prostate, lowered cholesterol level, reduced the PSA level and increased testosterone level in a dose-dependent fashion.
They declared, “The findings lend credence to cocoyam tubers as a strong candidate for the treatment of benign prostatic hyperplasia.”
Cocoyam tuber is widely eaten as food in different parts of West Africa, including Nigeria when boiled, fried or mashed into a meal. Furthermore, the flour made from its boiled tuber is used as a soup thickener in the preparation of soups in south-eastern Nigeria.
Cocoyam offers a number of potential health benefits, including better blood sugar control. Vitamin C and a complex of B vitamins, such as niacin, riboflavin and thiamine, important for the diet are present in significant amounts in cocoyam tubers and leaves.
Some of the medicinal properties that have been associated with cocoyam include treatment of ringworm, fungal infections, ulcers, cough, sore throat, wounds and diabetes mellitus. Its leaves are rich in beta‐carotene, iron and folic acid and contribute to the prevention of kidney stones.
Medicinal plants have traditionally been used to support urinary tract symptoms. Clinical researchers at the University of Graz, Austria, demonstrated that supplementation with pumpkin seed extract could help relieve the symptoms of Benign Prostatic Hyperplasia (BPH).
The study found that 500mg daily supplementation with the pumpkin seed extract supplement significantly reduced every BPH related symptom after four weeks of intake. They took it before going to bed for three months.
In the study, 58 male subjects between the ages of 50 and 75 suffering from symptoms of BPH for at least six months before screening were given 500mg of pumpkin seed extract daily for three months. They were monitored every four weeks.
The researchers in the Journal of Medicinal Food said that 35.7 per cent of men reported an improvement of symptoms from ‘moderate’ or ‘severe’ to ‘mild’ and nocturia and post-void residual urine volume was significantly reduced.
In addition, research evidence said that prostate-specific antigen (PSA) concentrations significantly decreased in the group fed diets incorporated with bitter leaf.
The 2016 study, published in the Nigerian Society for Experimental Biology had investigated the effect of dietary incorporation of Vernonia amygdalina and Vernonia colorata on prostatic and testicular functions in rats.
It indicated that at 10 per cent of dietary incorporation of these leafy vegetables, Vernonia amygdalina demonstrated a stronger efficacy than Vernonia colorata in lowering blood testosterone concentrations and PSA.
Also, it recorded a reduction in prostatic acid phosphatase (PACP) concentrations and weight of the testicles, all suggesting that bitter leaf, irrespective of its variety may have beneficial properties in the management of prostatic conditions.
Other food items protective of the prostate are Dacryodes edulis fruit (local pear), Moringa oleifera, clove, tomatoes, citrus fruits, Soursop (Annona muricata), soya beans and chili pepper.
In addition, medicinal plants identified to be helpful include Pygeum africanum (African plum tree or bitter almond) is called ‘emi’ or ‘olowomefa’ in Yoruba, ‘ka’danya’ in Hausa and ‘osisi’ in Igbo. Urtica dioica (nettle, big string nettle, common nettle, stinging nettle) is called ‘agbara’ or ‘akuwa’ in Igbo and ‘ewe esinsin’ or ‘esisi’ in Yoruba.