Can regular intake of tigernuts protect against stroke, infertility in men and diabetes? Recent studies have demonstrated how the local delicacy enhances optimal health.
Botanically called Cyperus esculentus, tigernut belongs to the Cyperaceae family. It is commonly known as earth almond, tiger nut, chufa, yellow nutsedge and Zulu nuts. It is known in Nigeria as aya in Hausa, ofio in Yoruba and akiausa in Ibo where three varieties (black, brown and yellow) are cultivated. Among these, only two varieties, yellow and brown are readily available in the market.
The yellow variety is preferred to all other varieties because of its inherent properties like its bigger size, attractive colour and fresher body.Tiger nut can be eaten raw, roasted, dried, baked or be made into a refreshing beverage called tigernut milk. The biologically active compounds in tiger nut include as follows: alkaloids, saponins, flavonoids, glycosides, phenols, steroids, phlobatannins, and terpenoids. Cyperus esculentus has the high contents of Vitamins (A, C, D, and E), minerals (sodium, calcium, iron, zinc, potassium, magnesium, and phosphorus), protein, starch, and fat.
Until now, Cyperus esculentus was reported to help in preventing heart, thrombosis and activates blood circulation, responsible for preventing and treating urinary tract and bacterial infection, assist in reducing the risk of colon cancer, anti-diabetic, weight-losing effect, and possesses anti-sickling property Previous research indicated that Cyperus esculentus may play an important role in enhancement of fertility.
However, the results of the most recent study published this January in Neural Regeneration Research showed that a flavonoid in tiger nuts, orientin, has neuroprotective effects on stroke injury.
According to the study, Cyperus esculentus Orientin (CLO) could decrease neurological deficit score, attenuate brain water content, and reduce cerebral infarct volume, leading to neuroprotection during cerebral ischemia-reperfusion injury.
The researchers wrote: “Our studies indicate that CLO flavonoids can be taken as a natural antioxidant and bacteriostastic substance in food and pharmaceutical industry. The molecular mechanisms of CLO could be at least partially attributed to the antioxidant properties and subsequently inhibiting activation of casepase-3….”
The study is titled “Neuroprotection of Cyperus esculentus L. orientin against cerebral ischemia/reperfusion induced brain injury.”The researchers added: “Orientin is a flavonoid monomer. In recent years, its importance as a source of pharmacological active substance is growing rapidly due to its properties such as anti-myocardial ischemia, anti-apoptosis, anti-radiation, anti-tumour, and anti-ageing. However, the neuroprotective effects of Orientin on stroke injury have not been comprehensively evaluated.
“The aim of the present study was thus to investigate the neuroprotective capacity and the potential mechanisms of Cyperus esculentus L. orientin (CLO) from Cyperus esculentus L. leaves against ischemia/reperfusion (I/R) injury using standard orientin as control. For in vitro studies, we treated HT22 cells with CoCl2 as an in vitro ischemic injury model. HT22 cells in the control group were treated with CoCl2. For in vivo studies, we used rat models of middle cerebral artery occlusion, and animals that received sham surgery were used as controls.
“We found that CLO protected CoCl2-induced HT22 cells against ischemia/reperfusion injury by lowering lipid peroxidation and reactive oxygen species formation as well as decreasing protein oxidation. However, CLO did not reduce the release of lactate dehydrogenase nor increase the activity of superoxide dismutase. Results showed that CLO could decrease neurological deficit score, attenuate brain water content, and reduce cerebral infarct volume, leading to neuroprotection during cerebral ischemia-reperfusion injury….”
The Chinese and United States researchers are from Yingdong College of Food Science and Engineering, Shaoguan University, Shaoguan, Guangdong Province; School of Bioengineering, Jiangnan University, Wuxi, Jiangsu Province; Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX; and College of Life Sciences and Technology, Xinjiang University, Urumqi, Xinjiang Uygur Autonomous Region.
Also, researchers have demonstrated how tiger nuts protect against testicular damage. The researchers concluded: “The results suggest that Cyperus esculentus could enhance testicular activity and ameliorate the adverse effect of flutamide on the testis.”
The study published in Journal of Experimental & Clinical Anatomy is titled “Curative effect of aqueous extract of Cyperus esculentus on flutamide-induced testicular dysfunction in male Wistar rats.”
Flutamide has been reported to affect serum testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, and spermatogenesis resulting in male reproductive dysfunction and infertility. Flutamide is a toluidine derivative and a nonsteroidal antiandrogen used primarily to treat prostate cancer and also for hormone therapy.
The researchers are from the Department of Anatomy, Faculty of Basic Medical Science, College of Medicine, University of Nigeria Enugu Campus, Enugu State; and Department of Anatomy, College of Medical Science, Ebonyi State University, Abakaliki, Ebonyi State.
The health of the testis is important for a man’s sexual functioning and fertility. The study investigated the effect of aqueous extract of Cyperus esculentus on flutamide-induced testicular dysfunction in male Wistar rats.
Sixteen adult male Wistar rats were randomly divided into the following four groups: A–D (four). Group A was given distilled water, and Group B was given 5mg/kg body weight of flutamide daily for the period of the experiment. Group C was given 5mg/kg body weight of flutamide one hour before treatment with 150mg/kg body weight of an extract of C. esculentus, and Group D was given 5mg/kg body weight of flutamide one hour before treatment with 300mg/kg body weight of an extract of C. esculentus for 21 days.
The hormonal assay showed that the extract produced a significant increase in serum testosterone and luteinizing hormone compared to the controls. The light microscopic study revealed degenerative changes in the germinal epithelium and interstitial tissue of the rats treated with flutamide, whereas the extract produced a marked increase in the number and volume of cells in the germinal epithelium compared to the positive control.
Researchers have also demonstrated the ameliorative potentials of Cyperus esculentus oil on Type 2 diabetes induced by high fat diet and low dose Streptozotocin in male Wistar rats.
The researchers concluded: “Dietary based therapies may be potent alternative for managing and preventing diabetes and its related complications. The result of the present study revealed that Cyperus esculentus oil, significantly aided weight reduction, reduced blood sugar levels, stabilized glycated hemoglobin, glucose 6 phosphate dehydrogenase, inhibited α-Amylase, improved the lipid profile status and enhanced antioxidant capacity. Therefore, Cyperus esculentus oil may be used as either a therapeutic agent or as a dietary choice for the management of type 2 diabetes.”
The study was published in the International Journal of Diabetes Research.The researchers are from the Nutritional and Industrial Biochemistry Unit, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Oyo State.The aim of the study was to investigate the ameliorative potentials of Cyperus esculentus (Tigernut) oil, in type 2 diabetes induced with the combination of high fat diet and a low dose streptozotocin (35mg/kg) in male Wistar rats.
Forty rats weighing between 100-115g were divided randomly into group of five (eight in each), three groups were subsequently fed with a high fat diet (HFD) for 30 days and the other two were maintained on normal rat chow (NPD). Results revealed an increase in body weight amongst the groups fed with a HFD and treatment with C. esculentus oil significantly reduced the body weight (HFD+STZ+CEO). Glycated haemoglobin (HbAIC), G6PDH and α-Amylase activity were significantly stabilized in C. esculentus oil treated group. Oral glucose tolerant test with a load dose of 150mg/kg glucose showed there was a rapid blood sugar level clearance in HFD+STZ+CEO as compared to untreated group (HFD+STZ). Atherogenic index (AIP) levels was significantly lowered in the treated groups when compared to untreated groups as well as triglyceride and Very-low-density lipoproteins (VLDL) levels.VLDL cholesterol is a type of blood fat. It is considered one of the “bad” forms of cholesterol, along with LDL cholesterol and triglycerides.