**5. Biological activities**

**Corn part Extracting solvent FRAP** *CRC* **References** Corn silk Water 35.01% [87]

Corn kernel Methanol 6.4–12.7 37 μM TE/g dw [95]

0.09 μmol Fe(II) E/g fw 0.10 μmol Fe(II)/g dw 13.1–26.1 μM TE/g

Corn cob Various polarity solvents 35.81–41.39% EC50 (218.1–735.0 μg/ml) [93, 97] Corn leaves Various polarity solvents EC50 (152.3–248.8 μg/ml) [97] Corn husk Various polarity solvents EC50 (205.7–723.4 μg/ml) [97]

Methanol acidified with HCl 9 ± 2 mmol TE/100 g dw [95]

FRAP, ferric-reducing antioxidant power; *CRC*, cupric-reducing capacity; EC50, effective concentration required for 50%

**Corn part Extracting solvent DPPH ABTS References** Water 63.5% [89]

Corn silk Ethanol 84%, 68–75.6% [78]

13.15%, 28.7% fw, 34.2% dw,

(52–177 mg/ml)

10.48–13.46%

Methanol 81.7% [89] Methanol IC50 (0.10–0.18 mg/ml) [18] Methanol 41–76% [19] Methanol IC50 (140.89 μg/ml) [99]

Ethanol IC50 (143.55 μg/ml) [99] Ethanol-water 92.6% with IC50 (0.56 mg/ml) [6] Ethyl acetate IC50 (411.69 μg/ml) [99]

IC50 (195.21 μg/ml) [99]

81.7–71.5% [89]

68.4–75.6% [57] IC50 (140.89 μg/ml) [87]

IC50 (219–799 μg/ml) [40, 98]

5–14 μM TE/g dw 11 ± 2 mmol TE/100

g dw

49.2 μM ET/g [41]

[61, 91]

[95],

[61, 82, 98]

Methanol acidified with

56 Corn - Production and Human Health in Changing Climate

**Table 4.** Metal-reducing capacity of extracts from various parts of corn.

Corn seed Methanol IC50 (66.3–79.8 μg/ml) IC50

Methanol acidified with

Methanol acidified with

Ethanol acidified with

citric acid

citric acid

HCl

citric acid

inhibition; TE, Trolox equivalent.

Methanol 56.41% [87] Ethanol 51.16%, 38.90–65.46% [87, 93] Ethyl acetate 27.21% [87]

> Epidemiological studies have demonstrated a relationship between the consumption of food with high quantities of phenolic compounds and a reduction in the risks of chronic and degenerative diseases, such as cancers and cardiovascular disease. Corn seed possesses antidiabetic, antioxidant, antiproliferative, and anti-cataractogenic activities [18, 39–41].



tumors, hepatitis, heart problems, jaundice, malaria, inflammation, asthma prostatitis, cystitis, nephritis, kidney stones, bed wetting, renal conditions, and other kidney-related diseases. Corn silk is also known to be urine laxative, antihypertensive, and immune enhancer. Corn silk tea has been used as diuretic for the treatment of urinal irritation. In combination with other herbs, corn silk has been found to be effective against mumps or inflammation of the bladder. It has been also reported to be useful in gonorrhea, acute and chronic cystitis, and bladder irritation due to uric acid and phosphate gravel [11, 14, 37, 38, 42–44, 46, 47, 51, 54–59]. Recently, corn silk polysaccharides have been suggested to be a good choice as functional food or medicine for the treatment of type 2 diabetes mellitus due to its hypoglycemic

Phytochemical Composition: Antioxidant Potential and Biological Activities of Corn

http://dx.doi.org/10.5772/intechopen.79648

59

There are several factors which have been reported to affect the phytochemical quality and antioxidant potential of various parts of corn. The phytochemical composition and antioxidant profile of maize have been observed to be different in different varieties and at various stages of maturity [18, 61–63]. The phytochemical content of corn silk has been found to be enhanced by treatment with red algae [64]. The location, climatic, water stress, irrigation method, and plant density significantly affect the growth, metabolism, and physiological characteristics of corn plant [65–67]. The spraying of salicylic acid and collection period have been found to increase the growth rate and phytochemical content of corn silk [68]. The fermentation of corn samples has been found to result in an increase in carotenoid and ascorbic acid content with a slight decrease in antioxidant activity [69]. The germination conditions between light and dark periods have been also found to affect the morphological structures, biochemical and phytochemical composition, and antioxidant activity of corn sprouts [70]. The storage conditions, processing techniques, and cooking methods have been also found to affect the phytochemical content and free radical-scavenging activity of maize [21, 71]. Recently, studies in our laboratory have shown that high-dose gamma irradiation results in a decrease in

All parts of corn plant are good sources of phytochemical compounds which possess antioxidant potential. Corn seed have a valuable role in human nutrition, while corn silk has a great medicinal importance due the presence of a variety of bioactive phytochemical compounds. The principal phytochemicals present in corn silk include polyphenols, phenolic acids, flavonoids, anthocyanins, glycosides, carotenoids, and some water-soluble vitamins. The presence of these phytochemicals makes corn a medicinal plant which shows various biological activities particularly the antioxidant activity. On the account of its high antioxidant potential, all parts of corn plant can be used for the management of oxidative stress and the treatment of

**7. Factors affecting the phytochemical profile and antioxidant** 

activity [60].

**potential of corn**

antioxidant properties of corn flour [72].

**8. Conclusion**

various diseases.

**Table 6.** Biological activities of extracts from various parts of corn.

Corn silk has been traditionally used for the treatment of several ailments due to various pharmacological activities exhibited by its extracts. It has been found to possess antioxidant, antidiabetic, antiproliferative, antimutagenic, anticoagulant, antifungal, antiadipogenic, antiobesitic, antihypertensive, antihyperlipidemic, antilithiatic, antibiotic, antibacterial, antiseptic, anti-inflammatory, antidepressant, and anti-fatigue activities [6, 11, 34, 38, 42, 43]. It has been also reported to possess antihyperglycemic, antihyperlipidemic, diuretic, neuroprotective, hepatoprotective, and uricosuric activities [44, 45]. Corn silk has been investigated to activate the receptors for the binding of human peroxisome proliferator activators used in the treatment of diabetes [46]. Its methanolic extract has been found to be effective in thyroid dysfunction [47]. Corn silk extracts contain certain bioactive compounds which show immunomodulation activity [33, 48, 49]. Corn silk extracts have been also found to be effective in inhibition of tumor necrosis factor-α and adhesion of leukocytes to cell surface and induction of nitric oxide synthase and cyclooxygenase in macrophages [50–52]. The chemically modified corn silk polysaccharides have been reported to show antioxidant and amylase inhibitory activities [14]. Recently, the studies have shown that corn silk has no cytotoxic effect, but the excessive use of corn silk may be cardiotoxic particularly in patients with compromised cardiac health [4]. The biological activities of various extracts of different parts of corn are presented in **Table 6**.
