Investigation into the effect of malus domestica (apple) on the serum lipid profile

CHAPTER ONE

1.0             INTRODUCTION

1.1 BACKGROUND OF THE STUDY

Epidemiological studies have indicated possible relationships between diet and various chronic diseases, especially coronary heart disease, diabetes mellitus and some malignancies (Aprikian et al., 2001). A fruit and vegetable rich diet (at least 5 servings a day) can reduce the risk of coronary heart disease by lowering the cholesterol level ( Pajk et al., 2006).

Positive effects of fruits and vegetables have been attributed to dietary fibers, antioxidants and especially phenolic compounds. (Leontowicz et al., 2002; Alvarez-Parrilla et al., 2010).  Fibers and polyphenols are capable of improving the lipid profile in cardiovascular patients (Basu et al., 2010). Apple is one of such fruits which have been ascribed with the ability to lower incidence of and risk of coronary heart disease or cardiovascular diseases. The reason, according to research data, has to with its fiber and chemical components such as Flavonoids, Polyphenols and Carotenoids (Boyer and Liu, 2004).

The importance of apple can be explained by different factors including their availability in the market throughout the year in a variety of forms in the developed countries (fresh fruit, juice, cider, mashed apples) and also their reputation as a healthy food (Aprikian et al., 2002).

The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family (Rosaceae). It is one of the most widely cultivated tree fruits, and the most widely known of the many members of genus Malus that are used by humans. Apples grow on small, deciduous trees (Potter et al., 2007).

The proverb "An apple a day keeps the doctor away", addressing the health effect of the fruit, dates from 19^th century wales (Phillips and John, 1866)

Apples are often eaten raw; except for the seeds, which are slightly poisonous, the whole fruit including the skin is suitable for human consumption. Apples bred for this purpose are termed dessert or table apples. Apples can be canned or juiced. They are milled to produce apple cider (non-alcoholic, sweet cider) and filtered for apple juice. The juice can be fermented to make cider (alcoholic, hard cider), ciderkin, and vinegar.

          Through distillation, various alcoholic beverages can be produced, such as applejack, Calvados,and apfelwein. Pectin and apple seed oil may also be produced.

Sliced apples turn brown with exposure to air due to the conversion of natural phenolic substances into melanin upon exposure to oxygen (Boyer et al., 2004). Sliced fruit can be treated with acidulated water to prevent this effect. (Boyer et al., 2004).

Lipids are insoluble fats that are deposited in/on the walls of arteries which can lead to Coronary heart disease which is the narrowing or blockage of the coronary arteries, usually caused by atherosclerosis. Atherosclerosis (sometimes called “hardening” or “clogging” of the arteries) is the buildup of cholesterol and fatty deposits (called plaques) on the inner walls of the arteries. These plaques can restrict blood flow to the heart muscle by physically clogging the artery or by causing abnormal artery tone and function (Williams et al., 1998).

 Lipid profile is generally High density lipoprotein, Low density lipoprotein, Triglyceride and Total cholesterol. Cholesterol cannot be absorbed directly into the blood stream, it must rely on two lipoprotein to act as conductors (Candice, 2012) which are the High density lipoprotein and Low density lipoprotein.

High density lipoproteins are the body’s good cholesterol, delivery cholesterol to the cells and cleaning the artery of excess cholesterol. They are the body’s cleaner working in harmony with the body (Candice, 2012).

Low density lipoproteins are the body’s bad cholesterol and cause a plaque – like cholesterol build up along the wall of the arteries. This build up, over time, causes the arteries to narrow, thus decreasing blood flow and contributing to the possibility of stroke and heart diseases like coronary heart disease.

Apple is one of those fruits that can reduce this risk because it contains fiber and chemical components such as Flavonoids, Polyphenols and Carotenoids (Boyer and Liu, 2004).

Similarly, a study in Australia involving 1,600 adults showed apple and pear intake was associated with a decreased risk of asthma and a decrease in bronchial hypersensitivity, whereas total fruit and vegetable intake was not associated with asthma risk or severity (Woods et al., 2003).

In a study from Brazil, women consuming apples or pears 3 times daily had a lower blood glucose level when compared with women consuming oat cookies (De Oliviera et al., 2003).  From previous data’s, it had been shown that there is a link between increased blood sugar and increased lipid profile. Since apple can reduce blood sugar according to De Oliviera et al. (2003), I believe it will also have effect by reducing serum lipids.

Having known that apple has all these chemical compounds and effect, I have decided to investigate the effect of crude extract of apple on the serum lipid profile of albino rats.

1.2 AIM OF THE STUDY

To investigate the effect of crude extract of Malus domestica (apple) on the serum lipid profile of albino rat.

1.3 OBJECTIVE OF THE STUDY

To investigate the effect of crude extract of Malus domestica (apple) on Total Cholesterol (TC) of albino rats.

To investigate the effect of the crude extract of Malus domestica (apple) on Triglyceride (Trigly) of albino rats.

To investigate the effect of the crude extract of Malus domestica (apple) on High Density Lipoprotein Cholesterol (HDL-C) of albino rats.

To investigate the effect of the crude extract of Malus domestica (apple) on Low Density Lipoprotein Cholesterol (LDL-C) of albino rats.

1.4 SCOPE OF THE STUDY

This study was restricted to the use of adult albino rats due to ease at which blood sample can be gotten. It was also limited to the use of crude extract of Malus domestica (apple) on albino rats to check the effect on the serum lipid profile.

1.5 JUSTIFICATION OF THE STUDY

This study is to investigate whether or not, the crude extract of Malus domestica (apple) has effect on the serum lipid profile of albino rats.

1.6 SIGNIFICANCE OF THE STUDY

This research work will play a very significant role in the present day knowledge about the crude extract of apple and its effect on the serum lipid profile using experimental model (albino rats) and also to improve life and health by creating new drugs and food supplement from apple.