Nutritional and Biological Assessment of Some Dietary Estrogen

Nutritional and Biological Assessment of Some Dietary Estrogen

¹Suzan Abd El Rhman Saad, ²Rabab, H. Salem and ³Ensaf, M. Yassin

^1,3Nutrition and Food Sciences Department, Faculty of Home Economic, Al Azhar University, Tanta, Egypt.

²Food Science and Technology Department, Faculty of Home Economic, Al- Azhar University, Tanta, Egypt.

Abstract

This study was conducted to evaluate the nutritional and biological activity of some dietary estrogen such as sunflower seeds, barley grains and its effect on adult female albino rats. Chemical proximate, minerals content, quantitation of water-soluble vitamins, tocopherols content and HPLC-MS detection of phytoestrogens of some dietary estrogen were measured. Forty adult female albino rats of Sprague Dawley strain (150 ±5 g) were used and randomly divided into 8 equal groups, one was kept as a negative control group, while the other 5 groups fed on basal diet with dietary estrogen (sunflower seeds, barley grains)( 30 ، 40 % ),  group seven fed a dose of drug(17 βeta-estradiol (E2) in a dose of 2.7µg/day), group eight fed mix from 30 % both of sunflower powder ,barley powder  and drug. The hematological analysis, lipid profile, oxidative stress and hormonal assay were examined.

The obtained results concluded that seeds of sunflower contained the highest crude protein (23.79%) content. The highest crude fiber contents (3.65%) in whole barley, minerals content in whole barley was found relatively lower than the seeds of sunflower. Tocopherol (natural antioxidants) of sunflower seeds achieved the scores of (40.49 mg/100g).Using dietary estrogen improved lipid profile, antioxidant enzymes and liver functions. According to the results, sunflower seeds, barley grains could be used for impaired lipid profile and protection from osteoporosis.

Introduction

Phytoestrogens are a group of pharmacologically active non-steroidal polyphenols found in a variety of plants and dietary products (Xu et al., 2000). Estrogen replacement therapy (ERT) is widely used for the treatment of peripheral menopausal symptoms, and the prevention of osteoporosis, with a view to appear a strong relation between mood and hormonal status in women (Halbreich and Kahn, 2001). Estrogens are steroid hormones, it's known for the effect on the female reproductive organs. The principal function is to cause cellular proliferation and growth of the external female sex organs and the uterus. Moreover, changes of the endometrium and Fallopian tubes take place under the influence of estradiol. Further, estradiol has profound effects on osteoblast and -clast activity, as illustrated by the increased prevalence of osteoporosis in postmenopausal women and on cardiovascular function (Gruber et al.,2002).

The word phytoestrogen from “phyto” meaning plant, and “estrogen” due to their ability to affect estrogenic activity in the body. Phytoestrogens are peripheral partial agonists of estradiol receptors (ER) with varying affinity for each receptor subtype but generally exert weak estrogenic activity (Mueller et al., 2003). Whether phytoestrogen intake results in clinically relevant reproductive impairment in humans is less clear. Most of the human literature concentrates on is flavones (structural and functional similarity to 17β-estradiol), a class of phytoestrogens primarily which appear to have beneficial reproductive effects among women (Krebs  et al .,2004 and Shahin  et al.,2008).

The common sunflower (Helianthus annuus L.) is a species of the Asteraceae family grown commercially worldwide offering a variety of nutritional and medicinal benefits (Prolea, 2012). The sunflower seed contain valuable antioxidant, antimicrobial, antiinflammatory, wound-healing, and cardiovascular benefits found in its phenolic compounds, flavonoids, polyunsaturated fatty acids, and vitamins(Fowler, 2006). Fisk  et al. (2006) determined the total phenolic contents in sunflower seeds and found to be 2700 mg/100g on dry weight basis. Flavonoids and phenolic acids have been identified from the sunflower seed and shown to contribute to its pharmaceutical activities (Pająk et al .,2014).

Barley (Hordeum vulgare L.) grain play an important role in meeting the nutrient needs of the human population. They are a good excellent sources of some nutrients (Newman and Newman, 2006 and Adil et al., 2012). Phytochemicals in barley may exist in free, conjugated, or bound forms and are categorized into several major classes, including phenolic acids, flavonoids, lignans, tocols, phytosterols, and folates (Fogarasi  et al ., 2015) .Barley grain contains a wide range of phenolic acids (Zielinski and Kozlowska, 2000). Kim et al., (2007) studied the flavonoid content of 127 lines of hulled and unhulled barley wherein the total flavonoid content was found to range between 62.0 and 300.8 mg/g.

The aim of this study to evaluate the nutritional and biological activity of  some dietary estrogen such as sunflower seeds, barley grains and its effect on the heamatological analysis, lipid profile, oxidative stress and hormonal assay by using female white albino rats compared with conjugated estrogen drug.

Materials and Methods

Materials

Egyptian Sunflower seeds used in this study were obtained from Oil Crops Research Dept., Field Crops Research Institute, Agricultural Research Center, Giza , Egypt. Egyptian Barley grains Giza130 (hull-less barley) were provided from Barley Research Dept., Field Crops Research Institute, Agricultural Research Center, Giza, Egypt.

17- Beta-estradiol (E2) was obtained from El-Gomhorya Company for Chemicals and Drugs, Tanta City, El -Gharbia Governorate, Egypt.

Forty adult female albino rats of Sprague Dawley strain (150 ±5 g) were obtained from the animal colony, Helwan farm, Vaccine and Immunity Organization, Ministry of Health, Cairo Governorate, Egypt.Animals were acclimatized to laboratory condition before being used at Nutrition and Food Sciences Department, Faculty of Home Economic, Al Azhar University, Tanta, Egypt.

The basal diet was composed of 12 g of casein (10 % protein); 10g of corn oil (10% fat ) ; 4 g of minerals mixture (4 % minerals);  1g of vitamins mixture (1% vitamins ); 4g cellulose (4% fiber); and 71 g of corn starch (71 % starch), as shown in (Jerome  et al., 2002). The mineral mixture used in the experiment was prepared according to (Hegsted et al., 1941 ). While, the vitamin mixture was prepared as described by (Campbell, 1963).

Methods

Preparation of dietary estrogen

            Seeds of Sunflower (after remove peels) and barley grains were grind. The samples were ground in a mill to obtain a fine and homogeneous powder (60 mesh) and stored in plastic bags until analysis.

Preparation of reference drug

17-beta estradiol was freshly prepared by grinding and suspending one tablet (50 µg) in 10 ml distilled water. The drug was given in a single dose 2.7µg/day three times per week.

Experimental design and animal groups

Animals were individually kept in wire cages under hygienic conditions in a room maintained at 70% humidity, 20–25°C temperature and 12h light-dark cycle. Diet was introduced (ad libitum) to the rats in special food containers to avoid scattering. Similarly, fresh water was provided ad-libitum and checked daily. Adapted rats were randomized into eighth groups as follow:-

The first group (5 rats): was fed on basal diet and kept as a negative control group .

The second group (5 rats) : was fed on basal diet with 30 % sunflower seed powder  (300 g sunflower  powder /kg diet).

The third group (5 rats)  : was fed on basal diet with 40 % sunflower seed powder (400 g sunflower powder /kg diet).

The fourth  group (5 rats ) : was fed on basal diet with 30 % barley grain powder (300 g barley powder /kg diet).

The fifth group(5 rats): was fed on basal diet with 40 % barley grain powder (400 g Seeds of barley powder /kg diet).

The sixth group (5 rats) : was fed on basal diet with drug, 17 βeta-estradiol (E2) in a dose of 2.7µg/day three times per week.

The seventh group (5 rats) :  was fed on basal diet with mix from 30 % both of sunflower seed powder and barley grain powder ).

The eighths group (5 rats) : was fed on basal diet with mix from 30 % both of sunflower seed powder ,barley grain powder  and drug(17 βeta-estradiol (E2) in a dose of 2.7µg/day .

Study parameters    

Chemical characteristics of some dietary estrogen

The moisture content was determined as the loss in weight of samples after drying in hot air oven at 105°C to reach a constant weight ; crude protein was analyzed using micro kjeldahl method ;crude lipid content was determined by soxhelt apparatus for 16 hours using petroleum ether (60-80^◦C, Pb) as a solvent; crude fiber was analyzed by boiling with sulphuric acid and sodium hydroxide ;total ashwas analyzed byusing muffle furnace at 550°C for 6 hours until reach constant weight (AOAC 2010). Carbohydrate content was estimated by difference as follow: Total carbohydrates % = 100- (%protein +% fat +% ash + %crude fiber+ % moisture) according to procedure of Tadrus, (1989).

Determination of minerals content

Ca, Fe, Na, K and Zn were determined using flame atomic absorption spectrometry (Victoria, A5616 , Australia), according to ISO/IEC 17025 (2005). Phosphorus content was determined colorimetrically according to the method of (Murphy and Riley, 1962), at Central laboratory of Environmental Studies, Kafr_Elsheikh University, Kafr_Elsheikh Governorate, Egypt.

Quantitation of water-soluble vitamins

An Agilent 1100 chromatographic system (Agilent Ltd., South Queensferry, UK) was used for the analysis and quantitation of water-soluble vitamins in barley extract according to the meth