Corn silk repairs damaged kidneys, bursts renal stones

The mouth organ is in season. Corn also called maize is best known for its fruit with seeds/grains. The fruit has become the commonest and easily the cheapest snack in most parts of the country.

Botanically called Zea mays, corn belongs to the Poaceae family, and while eaten sometimes as a vegetable and sometimes as a grain, it is actually classified by botanists as a fruit, as are tomatoes, green peppers, cucumbers, zucchini and other squashes.

The fruit is reputed for its high fibre, mineral and vitamin content. But recent studies have shown the extracts of corn silk to be effective in repairing damage to the kidney, bursting kidney stones, preventing prostate cancer and treating urinary incontinence.

Corn silk is a yellowish thread like strand of female flower of maize.Phytochemical screening of the corn silk showed the constituents include alkaloids, tannins, phytosterols, vitamin E and K, succinic acid, lactic acid, palmitic acid, proteins, vitamins, flavonoids, terpenoids, carbohydrates, calcium, magnesium and potassium salts.

Potential use of corn silk is related to its properties and mechanism of action of its bioactive constituents such as flavonoids and terpenoids. Studies indicate that it possess antihypertensive, antioxidant, anticancer, antidepressant, kaliuretic, neuroprotective properties.

A new study has indicated renal function improving action of corn silk and binahong in gentamicin-piroxicam induced kidney failure.The study titled “Study of Kidney Repair Mechanisms of Corn Silk (Zea mays L. Hair)-Binahong (Anredera cordifolia (Ten.) Steenis) Leaves Combination in Rat Model of Kidney Failure” was published in International Journal of Pharmacology.

Anredera cordifolia, commonly known as the Madeira vine or mignonette vine, is a South American species of ornamental succulent vine of the family Basellaceae. The combination of fleshy leaves and thick aerial tubers makes this a very heavy vine

Taken together, results of this study suggest that corn silk in combination with binahong possesses renal function improving activity which is slightly better compared to the activity of each extract alone. The results further indicate that reduction of oxidative stress by each extract as well as their combination might be beneficial to the repair of renal damage.

Another study published in the International Journal of Pharmaceutical Sciences Review and Research by Indian researchers from the S. N. Institute of Pharmacy, Pusad, Dist –Yavatmal, corn silk could be used to burst kidney stones.

The researchers found that corn silk was playing an important physical role in treatment by increasing the contraction of smooth muscles a led to increase the urinary output and increased the percentage the passage of urinary stones through the urinary tracts.

The study is titled “In-vitro Anti-Urolithiatic Activity of Corn Silk of Zea Mays.”
The researchers noted: “Kidney stone is one of the most important problems in different countries over the world. They are affected by different factors like nutrition, age, drug history and other environmental and family factors. Locally, corn silk used as decompose of stones. This study proved aqueous extracts of corn silk of Zea mays executed on generated calcium oxalate crystals by homogenous precipitation method for in-vitro anti-urolithiatic activity.

“The aqueous extracts of corn silk of Zea mays as shown significant activity on comparison to the synthetic drug Spironolactone, furosemide and poly-herbal formulation Cystone.

“The plant drugs survey of corn silk of Zeal mays narrates that; the drug has been utilized for preclinical and clinical activities. “Corn silk is a rich source of potassium, soothing, relaxing diuretic and a wonderful remedy for acute inflammation of the urinary system, such as cystitis, urethritis and prostatitis.

“Also helping the passage of urinary stones. Corn silk encourages urination, while the potassium in the herb offset potassium loss caused by increased urination. It contains flavonoids (may sin), Allantois, Alkaloids, Sapiens, Volatile oil, Mucilage, Vitamins B, C and K, Silicon.”

Another study published in European Journal of Biomedical and Pharmaceutical Sciences listed the pharmacological activities of corn silk to include:

Anti-oxidant activity
Aerobic organisms to prevent oxidation that can damage the cells during oxygen metabolism use antioxidants. The latest studies have revealed the potential use of Corn Silk (CS) extracts as an important bioactive source of natural antioxidants.
Diuresis and kaliuresis effect

Diuresis is a discharge of urine in a large amount, while kaliuresis is the secretion of potassium in a large amount in urine. The effects of corn silk aqueous extract on the urinary excretion of potassium and glomerular function were studied.

Wistar rats administered with corn silk aqueous extract by orogastric catheter and urine collected for three and five hours exhibited diuresis and kaliuresis effect. Anesthetized Wistar rats administered with 1ml of 20 per cent corn silk aqueous extract by intragastric route, cannulation to urinary bladder for urinary flow, collection of urine detected diuretic effect.

Hyperglycemic effect
Hyperglycemia is a condition where there is an abnormally elevated level of glucose in the blood. Corn silk aqueous extract has the property to reduce hyperglycemia and it can be used as a hypoglycemic food for diabetic people. Adrenaline induced hyperglycemia in mice treated with corn silk aqueous extract by oral route for 14 and 45 days at dose of (0.5, 1, 2, 4 g/kg of body wt.) lowered blood glucose level at dose of 2 and 4 mg/kg.

Nephrotoxicity activity
Nephrotoxicity is a term used to categorize any adverse functional or structural changes in the kidney. The effects of these changes are due to chemical or biological products that are injected, ingested, inhaled or absorbed which yield toxic metabolites with adverse effects on the kidneys. Gentamicin induced nephrotoxicity in mice administered with corn silk methanol (80 per cent) extract at 200- 300 mg/kg for eight days ameliorates nephropathy.

Anti-fatigue activity
Anti- fatigue activity of corn silk was investigated by using swimming exercise in mice administered with flavonoids of corn silk with 100 and 400 mg/kg for 14 days and loaded with five per cent of body weight of galvanised wire possessed significant anti- fatigue activity.

Anti-depressant activity
Anti-depressant activity of corn silk ethanol extract was investigated by force swimming test (FST) and tail suspension test (TST) on 10 male Swiss mice for six and five minutes, respectively, one hour after treatment with 125, 250, 500, 1500 mg/kg extract, possessed good activity at the dose of 1500 mg/kg.

Anti-hyperlipidemic activity
Feeding the rats with hyperlipidemic feeds containing cholesterol, fat, sodium cholate, and ordinary feed conducted anti-hyperlipidemic activity. Total flavonoids from corn silk extracts showed an anti-hyperlipidemic effect on hyperlipidemia rats. The hyperlipidemia rats were treated with flavonoid from CS extract in three dosages (200, 400 and 800 mg/kg) for 20 days showed significant anti-hyperlipidemic activity at the dose of 400 and 800 mg/kg.

Anti-diabetic activity
The anti-diabetic effects of polysaccharides from corn silk (POCS) were evaluated by investigating the levels of blood glucose (BG), oral glucose tolerance test (OGTT), TC (total cholesterols) and TG (triglycerides) in streptozotocin (STZ)-induced diabetic rats for four weeks. The results revealed that POCS (100–500 mg/kg body wt.) decreased the BG, TC and TG levels.[26]

Haemodynamic effect
Haemodynamic effect was investigated by aqueous-ethanol (1:1) extract of corn silk administered to conscious rats by gastric intubation at a dose of 40 ml/kg, which detected hypotensive effect.

Anti-tumour activity
Anti-tumour activity of corn silk was investigated by aqueous extract of dried stigma and styles in mice by intraperitoneal route at a dose of 150 mg/kg on days five, six and seven after start of experiment, which found to possess significant anti-tumour activity.

Hepato-protective effect
Methanolic extract of corn silk in albino rat by oral route at a dose of 200 mg/kg. Hepatoprotective activity is due to inhibitory effect on free radical formation.The researchers concluded: “This review highlights potential therapeutic applications of corn silk. In vitro and in vivo studies are also conducted showing remarkable bioactivities of corn silk in various diseases. Toxicological findings showed safety and non-toxic nature for human consumption.”