Healthcare Benefits of Hordeum vulgare L (Barley):

A Phyto-Pharmacological Review

 

K. Rashid¹, C. Senthil Kumar², P. M. Mohammed Haleel³

¹Department of Pharmacology, Jamia Salafiya Pharmacy College, Malappuram, Kerala.

²Department of Pharmacology, Karpagam College of  Pharmacy, Coimbatore

³Ayisha Majeed College of Pharmacy, Vavvakkavu, Kollam, Kerala.

 

ABSTRACT:

Barley is one of the most ancient crops cultivated already some 1000 years ago. Barley cultivated for food and feed belongs to the species Hordeum vulgare L. For food purposes barley is mainly used as de-hulled grain or high fibre content products. Food produced from barley is a good source for many nutrients such as protein, fibre, minerals and B-vitamins. The fibre content of barley is high and rich in β-glucan that is mainly soluble. Fibre rich cereals such as barley are beneficial for balancing the human diet in a manner that is of  no relevance for animals. HV reveal a broad spectrum of pharmacological activities including antioxidant, hyperglycemia reduction, cardiovascular and neuropharmacological effects. The objective of this review to summaries the phyto-pharmaological information's of HV, which can be investigated further to get novel molecules in the search of novel herbal drugs.

 

 

 

INTRODUCTION:

Hordeum vulgare L. (barley) is one of three species of genus  Hordeum  belonging to the grass family Poaceae, is an annual crop used throughout ancient civilizations as an important food source. The genus Hordeum consists of 32 species and 45 taxa. All varieties of HV have hollow stems in the forms of cane, produced from the fibrous roots. There is a spike-shaped arrangement of seed at the end of every stem¹.

 

Barley is a one of the widely consumed cereal, because of its dietary and technological properties. In fact, barley meals and fractions are now gaining renewed interest as ingredients for the production of nutritious foods (pastas, baked products), due to their concentration of bioactive constituents, such as β-glucans and tocols².The consumption of  barley support  the body’s own self  healing mechanisms. The components of barley aid the body in maintaining cells in a healthy condition and work to rectify abnormalities.

 

Barley has been used as an aid in the treatment of a variety of conditions such as diabetes, skin abnormalities, arthritis, digestive diseases, weight loss, detoxifying and cancer etc³.

 

 

Figure 1.Barley plant and grains

So, the present article is an attempt to review the available scientific evidence in support of potential uses of HV in healthcare including its phytochemical, pharmacological, and botanical description.

 

Botanical description:

Barley is a member of the grass family Triticeae. Wheat and rye also fall into this grass family. In total, there are thirty-one barley species. Of the thirty-one, three-fourths are perennial grasses, blooming every summer and dying back in the winter. Although there are so many types of barley, scientists hypothesize that they all originated from one ancestor plant, the Hordeum spontaneum.

 

Taxonomic classification:

Kingdom              : Plantae - Plants

Subkingdom        : Tracheobionta - Vascular plants

Super division    : Spermatophyta - Seed plants

Division                              : Magnoliophyta - Flowering plants

Class                     : Liliopsida – Monocotyledons

Subclass                              : Commelinidae

Order                    : Cyperales

Family                  : Poaceae - Grass family

Genus                   : Hordeum – barley

Species                 : H. vulgare

 

Barley is an annual grass that strands 60-120 cm tall. Barley has two types of root systems, seminal and adventitious. The stems are erect and made up of hollow, cylindrical internodes separated by the nodes, which bear the leaves. A mature barley plant consists of lateral stem and 2-5 branch stems, called tillers⁴.

 

Barley leaves are linear 5-15 mm wide and are produced alternate sides of the stem. The leaf structure consists of the sheath, blade auricles and ligules. The sheath surrounds the stem completely. The ligules and auricles distinguishes the barley from other cereals as they are smooth, envelop the stem and can be pigmented with anthocyanins⁵.

 

Barley cell walls encapsulate starch granules embedded in a protein matrix. With thin cell walls and loose packing of endosperm, the large mealy grains allow a rapid water up-take and uniform distribution of water and enzymes synthesized during germination. On the contrary, due to thick cell walls and tightly packed endosperms, small steely grains retard mass transfer in the endosperm. Large, plumb kernels are desired for malting. The fraction above the 2.5 mm sieve is normally used for malting and the rest is included in the feed fraction. A larger uniform grain size is desired because it enables homogenous water up-take and modification⁶.

 

Nutritional Information:

One cup (237 ml) of cooked pearled barley contains 193 calories, while the whole-grain (hulled) form contains 270 calories and contains as much protein as a cup (237 ml) of milk.

 

Table 1.List of nutritional information of barley

 

Phytochemical composition:

The phytochemical constituents of barley is been tabulated under

 

Table 2. List of phytochemical constituents of barley

Components	Barley(% of dry matter)
Carbohydrates	78 – 83
Starch	63 – 65
Sucrose	1 – 2
Other sugars	1
Water-soluble polysaccharides	1 - 1.5
Alkali-soluble polysaccharides	8 – 10
Cellulose	4 – 5
β-glucan	1 – 4
Lipids	2 – 3
Nonpolar lipid (NL)	65 - 75
Glycolipids (GL)	6 – 26
Phospholipids (PL)	9 – 20
Protein	10 – 12
Albumins and globulins	3.5
Prolamins (hordeins)	3 – 4
Glutelins (hordenins)	3 – 4
Nucleic acids	0.2 – 0.3
Minerals	2
Calcium (Ca)	0.4 – 0.7  g/kg
Magnesium (Mg)	0.9 – 1.5  g/kg
Phosphorus (P)	2.3 – 4.2  g/kg
Sodium (Na)	0.2 – 2.7  g/kg
Potassium (K)	3.0 – 5.9  g/kg
Vitamins and Other matters	5 – 6

 

Pharmacological Studies for Potential Healthcare:

Healthcare is ultimately aimed for the prevention of diseases or illnesses in human. The barley and its bioactive components provide many benefits that can be tapped as potential natural products for healthcare applications. The pharmacological studies of Hordeum vulgare cover both in vitro and in vivo experimental models.

 

Antioxidant Activity:

Antioxidants are used by aerobic organisms to prevent the oxidation that can damage the cells during oxygen metabolism. Oxidation can cause a number of pathological states including cancer, diabetes, atherosclerosis, neurodegenerative disorder, inflammatory and aging. Natural antioxidants extract from fruits, teas, vegetables, cereals and medicinal plants have been investigated extensively due to their effectiveness in free radical elimination and claimed to be less toxic than synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxyl toluene (BHT). There are several classes of natural antioxidants and they include vitamins such as to copherols and vitamin C and phytochemicals such as polyphenols and flavonoids which are common to all plant sources⁷.

 

The antioxidant properties of phenolic compounds in grains have been associated with the health benefits attributed to these crops and the value-added products derived from them. Antioxidants may play an important role in the chronic disease prevention by arresting oxidative damage caused by reactive oxygen species (ROS) to vital biomolecules such as DNA, lipids, and proteins. The antioxidant and antiradical capacities of cereal extracts were thoroughly investigated using a variety of model systems including bulk oils, scavenging of DPPH radicals (DPPH), coupled oxidation of β-carotene and linoleic acid, liposomes, the total antioxidant activity (TAA) assay, and reducing power.

 

The measurements of antioxidant activity using a β-carotene-linoleate model system, radical scavenging capacity against DPPH, and reducing power based on the reduction of a Fe3+/K3Fe(CN)6 complex to the ferrous state were assessed in the barley crude extract and its fractions. The results indicated that barley possess marked antioxidant and antiradical capacities as compared to other grains such as wheat, rye, and triticale etc. Furthermore, the methanolic extract of the waxy barley and its fractions resembled in the aforesaid activities those from leguminous seeds, rapeseed and pulses. Phenolic constituents contained in the barley may have a future role as ingredients in the development of functional foods⁸.

 

Hepatoprotective activity:

Acetaminophen  induced liver damage was produced by the treatment of acetaminophen (3g/kg/d, p.o.) for three days. Other groups of rats were pretreated with two doses of  MEHV (methanolic extract of Hordeum vulgare)  seeds (300 and 500 mg/kg/d, p.o) and silymarin (200 mg/kg/d, p.o) 30 min prior to acetaminophen ingestion. Liver damage was evidenced by elevated levels of biochemical parameters such as serum glutamate oxaloacetic transaminase and glutamate pyruvic transaminase (SGOT and SGPT), alkaline phosphatase (ALP), total and direct bilirubin (TBL and DBL), lactate dehydrogenase (LDH), gamma glutamyl transferase (GGT), malondialdehyde (MDA), decreased level of total protein (TP) and reduced glutathione (GSH) along with increased his to pathological scores in the APAP control. Pretreatments with MEHV seeds produced significant reversal in the above biochemical parameters and reduced his to pathological scores of fatty degeneration, necrosis with significant evidence of regeneration. The results of this study indicate that pretreatment with MEHV seeds possessed the significant  hepatoprotective  activity. In conclusion, the possible mechanism of hepatoprotective action of methanolic extracts of Hordeum vulgare seeds may be due to its antioxidant activity as indicated by protection against increased lipid peroxidation and maintained glutathione contents⁹.

 

Hypoglycemic Effect:

Treatment of  alloxan induced diabetic rats with repeated doses of barley water and its components such as amino acids could restore the changes of the immunological and biochemical parameters to their normal levels after four weeks of treatment. The electron microscope results were supported biochemical and immunological findings of the study. The  result was found that barley and its components exerts antihyperglycemic effects and consequently may alleviate liver damage caused by alloxan-induced diabetes levels after four weeks of treatment^10.

 

Cardiovascular and Anti inflammatory activity:

Consumption of soluble fiber improves the risk factors for cardiovascular diseases and diabetes mellitus. Soluble fiber reduces plasma cholesterol concentrations, lowers postprandial plasma glucose, insulin concentrations and ameliorates insulin resistance. Most research on soluble fiber has focused on oats.

 

Barley, another excellent soluble fiber source, has received little attention. Many forms of barley or barley extracts have not been investigated in human subjects. So, research is needed to assess the health benefits of human consumption of barley and barley products including barley co-products, germinated barley foodstuff etc¹¹.

 

Inflammatory processes involve a series of events caused by numerous stimuli such as antigen antibody interactions, thermal or physical injury, infectious agents and ischemia. Pain felt from the inflammation is caused by the release of analgesic mediators. A number of plants have been reported to display inhibition of arachidonic acid (AA) metabolism and platelet aggregation.

 

HV exhibited activities against all the human platelet agonists used except  adenine diphosphate, and inhibited both COX and LOX pathways of AA metabolism. It also elevated the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). However, these activities were distributed in various fractions of HV. Aqueous fraction of HV was most potent in elevating SOD activity; chloroform fraction had concentrated compounds responsible for COX inhibition while n-hexane seems to possess compounds responsible for LOX inhibition as well as the only fraction enhancing the activity of GPx¹².

 

Anti microbial activity:

In a study the antibacterial activity of Hordeum vulgare plant extract was detected using three methods (well, disc and OD of broth culture). The results show that extract have 4 phytochemicals compounds before modification and one compound after modification. Antibacterial activity results show variations in bacterial sensitivity and different response by different methods. The OD of broth culture show the best results; five of the pathogenic bacteria inhibited by plant extract before modification, and two of these bacteria growth was decreased by plant extract after modification. Thus the use of HV extract as antiseptic agent in topical pharmaceutical preparation can be recommended^13`.

 

Neuropharmacological Effects:

Behavioral and neuronal biochemical possible effects were studied in experimental induced chronic mild stress in male albino rats under the effect of oral barley administration in comparison to venlafaxine.

 

The study was conducted on 40 male Wister albino rats, divided to five different groups. Four groups were subjected to social chronic mild stress. Drugs or saline were daily administered orally one week before stress induction and extended up to ten weeks. Behavioral, brain biochemical tests and serum magnesium were assessed at the end of the study. The study revealed significant change in the combined group on behavioral tests; forced swim test, saccharin preference test, elevated plus maze and when compared to barley extract group. Moreover, there was significant reduction in brain malondialdehyde level, no important change in brain nitric oxide level, while significant increase in serum magnesium level. Whereas, the barley extract group recorded a lowest significant improvement in behavioral, brain and serum biochemical examinations¹⁴.

 

CONCLUSION:

This review highlights the potential of Hordeum vulgare L. (barley) as a herbal drug for healthcare applications. It is a promising medicinal plant with wide range of pharmacological activities such as antioxidant, hyperglycemia reduction, cardiovascular and neuropharmacological effects etc. Some of the studies have confirmed the earlier findings and new research discoveries have proven that HV is safe and non-toxic. With the claims in healthcare potential, it is important to carry out preclinical and clinical evaluations to substantiate the claims and further enhance the confidence in its beneficial therapeutic effects for human consumption.

 

REFERENCES:

1.       Behall KM et al. Diets containing barley significantly reduce lipids in mildly hypercholesterolemic men and women. Am J Clin Nutr 2004, 80:1185–1193.

2.       Sharifi et al., Antioxidant activity, phenol and flavonoid contents of eleven Iranian barley grain varieties (Hordeum vulgare L.). World of Sciences Journal,5:88-94.

3.       Mokhtar et al., Biochemical and Immunological Study on the Effects of Barley and its Components as Hypoglycemic Agents in Diabetic Rats. American Journal of Biochemistry and Biotechnology 2 (1): 1-8, 2006.

4.       The biology Hordeum vulgare L. (barley), Department of Health and Ageing, Office of Gene Technology Regulator Australian Government, Versio :1, April 2008.

5.       Barley Entry prepared by Gina Egbert, 08 in College Seminar 235 Food for Thought: The Science, Culture, and Politics of Food Spring 2008.

6.       OECD2004, Consensus Document On Compositional Considerations For New Varieties Of Barley (Hordeum vulgare l.): Key Food And Feed Nutrients And Anti-Nutrients. Report No.12, environmental Directorate, OECD, Paris.

7.       Khairunnisa et al., Corn Silk (Stigma maydis) in Healthcare: A Phytochemical and Pharmacological Review. Molecules 2012, 17, 9697-9715.

8.       Ryszard et al., Antioxidant and Radical Scavenging Activities of a Barley Crude Extract and its Fractions. Czech J. Food Sci. Vol. 25, No. 2: 73–80.

9.       Shah et al. Protective Effect of Hordeum vulgare Linn. on Acetaminophen-Induced Liver Damage. J Young Pharm. 2009;1(4): 336-340.

10.    Mokhtar I et al. Biochemical and Immunological Study on the Effects of Barley and its Components as Hypoglycemic Agents in Diabetic Rats. Am. J. Biochem. and Biotech., 2 (1): 1-8, 2006.

11.    Joan M et al. Health Effects of Barley Consumption. Diet and Human Performance Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Center, United States Department of Agriculture Beltsville, MD 20705.

12.    Gul et al. Multiple pathways are responsible for Anti-inflammatory and Cardiovascular activities of Hordeum vulgare L. Journal of Translational Medicine 2014, 12:316.

13.    Mohammad A et al. Characterization and antimicrobial activity of barley grain (Hordeum vulgare) extract Int. J. Curr. Microbiol. App. Sci (2013) 2(8): 41-48.

14.    Inas E et al. Behavioral and neuronal biochemical possible effects in experimental induced chronic mild stress in male albino rats under the effect of oral barley administration in comparison to venlafaxine. Int J Physiol Pathophysiol Pharmacol 2013 ;5(2): 128-136.