by CHUKWUMA MUANYA
Can chewing the leaves of guava plant be the novel cure for infertility in men?
THERE is hope in the horizon for a local cure for infertility in men. New findings by Nigerian researchers suggest that the extracts of the leaves of Psidium guajava possess beneficial effects on sperm production and quality, and may thus improve the sperm parameters of infertile males with oligospermia and non-obstructive azoospermia.
The researchers from the Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Kwara State in a study published in African Journal of Medicine & Medical Sciences noted: “Reactive oxygen species (ROS), among other factors, have been implicated in the aetiology of male infertility. Thus, the roles of antioxidants at improving sperm production and quality are being investigated.
“The present study was designed to assess the effect of the ethanol extract of fresh leaves of Psidium guajava on the sperm parameters of healthy male Wistar rats.”
The study is titled: “Ethanol extract of the leaves of Psidium guajava Linn Enhances Sperm Output in Healthy Wistar Rats.”
The researchers noted that a total of 18 rats, weighing between 108 to124 grammes, were divided into three groups of six animals each. Animals in groups 1 and 2 were administered 250 mg/kg/d and 500 mg/kg/d of guava leaf extract (GLE) orally for 53 days respectively.
They wrote: “Group 3 animals received normal saline. Sperm count increased from 56.2+/-0.3 (x10(6)) in the control to 57.1+/-0.2 (x10(6)) in group 1 animals, and from 56.2+/-0.3 (x10(6)) in the control to 72.3+/-0.4 (x10(6)) in group 2 animals. Similarly, dose-dependent increases in the percentages of motile spermatozoa were observed in GLE-treated animals compared to the control group.”
Medical experts describe oligospermia, also oligozoospermia, as semen with a low concentration of sperm, and is a common finding in male infertility. Often semen with a decreased sperm concentration may also show significant abnormalities in sperm morphology and motility.
According to medical experts, azoospermia is the medical condition of a male not having any measurable level of sperm in his semen. Several studies have associated it with very low levels of fertility or even sterility, but many forms are amenable to medical treatment. According to earlier studies, in humans, azoospermia affects about one per cent of the male population and may be seen in up to 20 per cent of male infertility situations.
Botanically called Pisidium guajava, guava belongs to the plant family Mytrtaceae. It is one of the plants acclaimed to exhibit antibacterial activity. It is believed to be a native of Brazil. The plant has been extensively used in the treatment of cough, sore throat and inflamed gums. Its medicinal effects have spurred many researchers into studying the properties of its extracts.
Previous researches had shown that guava aqueous extract is also attractive for use as a mouthwash because of some its active ingredients, which have been demonstrated to possess anti-oxidant properties, which are attributed to the polyphenols found in the leaves. These compounds are capable of neutralising Volatile Sulphur Compounds (VSC’s) and/or the compounds from which they are formed.
According to another study published in International Journal of Pharmacology and Biomedical Sciences, guava is rich in tannins, phenols, triterpenes, flavonoids, essential oils, saponins, carotenoids, lectins, vitamins, fiber and fatty acids. Guava fruit is higher in vitamin C than citrus (80 mg of vitamin C in 100 g of fruit) and contains appreciable amounts of vitamin A as well. Guava fruits are also a good source of pectin – a dietary fiber. The leaves of guava are rich in flavonoids, available in the tropics and within the reach of the local populace.
Guava contains broad spectrum of phytochemicals including polysaccharides, vitamins, essential oils, minerals, enzymes, proteins, sesquiterpenoid alcohols and triterpenoid acids, alkaloids, glycosides, steroids, flavanoids, tannins, saponins. Psidium guajava or guava is very rich in antioxidants and vitamins and also high in lutein, zeaxanthine and lycopene in particular, quercetin.
Much of guava’s therapeutic activity is attributed to these flavonoids. The flavonoids have demonstrated antibacterial activity. Quercetin is thought to contribute to the anti-diarrhea effect of guava; it is able to relax intestinal smooth muscle and inhibit bowel contractions. In addition, other flavonoids and triterpenes in guava leaves show antispasmodic activity. Guava also has antioxidant properties, which are attributed to the polyphenols found in the leaves.
The study is titled: “A review on nutritional, medicinal and pharmacological properties of guava” by Baby Joseph of the Interdisciplinary Research Centre, Department of Biotechnology Malankara Catholic College, Mariagiri, Kaliakkavilai, Kanyakumari District, India.
Joseph wrote: “In a study carried out with leaf extract of the plant, inhibition of gastrointestinal release of acetylcholine by quercetin present in extract was suggested as a possible mode of action in the treatment of acute diarrheal disease. Guava fruit and leaf showed antioxidant and free radical scavenging capacity. Guava leaf extract showed anti-cough activity by reducing the frequency of cough induced by capsaicin aerosol. Leaf extract of guava had inotropic effect on guinea pig atrium.”
“In the pharmacological actions and the medicinal uses of a guava leaves extracts have also been indicated to cause disturbances of the central nervous system: insomnia, convulsions and epilepsy. Bronchitis, asthma attacks, cough, pulmonary diseases could be also treated with guava teas and could also be useful as anti- inflammatory and hemostatic agent.
“Moreover, aqueous extracts of guava leaves were described to be effective against a number of microbial strains: Aeromonas hydrophila, Shigella spp. and Vibrio spp., Staphylococus aureus and ?- streptococcus group A, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis. In addition, anti-rotavirus activity has also been reported to exist in these extracts.
“During various episodes of screening of medicinal plants, extract from P. guajava leaves exhibited significant inhibitory effect on the protein tyrosine phosphatase1B (PTP1B). Significant blood glucose lowering effects of the extract were observed after intraperitoneal injection of the extract at a dose of 10 mg/kg in both 1- and 3-month-old Lepr(db)/Lepr(db) mice (Oh et al. , 2005). In a study of aqueous extract of P. guajava in acute experimental liver injury induced by carbon tetrachloride, paracetamol and thioacetamide, it showed hepatoprotective activity. The effects observed were compared with a known hepatoprotective agent, silymarin. Histological examination of the liver tissues supported hepatoprotection.
“Another study investigated that the hypoglycemic and hypotensive effects of P. guajava leaf aqueous extract in rats, it showed hypoglycemic activity. The hypoglycemic effect of plant extract was examined in normal and diabetic rats, using streptozotocin (STZ)- induced diabetes mellitus model.
“In a study, treatment with 1 g/kg guava juice produced a marked hypoglycemic action in normal and alloxan-treated diabetic mice. The aqueous extract of Psidium guajava budding leaves (PE) bears an extremely high content of polyphenolic and isoflavonoids. It could be used as an anti-tumor chemopreventive in view of anti-angiogenesis and anti-migration, indicated that the IC50 of PE for DU145 cells was 0.57 mg ml–1.
Source: The Guardian