RESEARCH PROPOSAL ON ANTI DIABETIC EFFECT OF
BITTER LEAF, WALNUT AND THEIR COMBINATION ON
WISTAR ALBINO RATS INDUCED WITH TYPE 1
DIABETES.
CHAPTER ONE
1.0 INTRODUCTION
Diabetes is one of the oldest diseases of human kind whose devastating effect is increasing by the day and severity almost at epidemic level (wide, et al., 2004). It is a disease of disordered metabolism of carbohydrate, that also affect protein and fat which is caused by complete or relative insufficiency of insulin action (mycek, 2000). There are three types of diabetes; two are related to insulin, which regulate blood sugar levels. Type 1diabetes called insulin-dependent diabetes mellitus (IDDM) and Type 2 diabetes called non-insulin dependent diabetes mellitus (NIDDM) are related to insulin while gestational diabetes (GDM) is not. The number of people with diabetes is increasing due to population growth, aging, urbanization, increasing prevalence of obesity and decrease physical activity (king and Rewers, 1993; Ramachnadran et al.,1999). The early symptoms of diabetes include elevated blood sugar levels (glycosuria), dehydration, weight loss, blurred vision.
Bitter leaf is a shrub or small tree of 2.5cm tall with the botanical name ‘Vernonia amygdalina’. It is commonly used in traditional medicine for various purposes. It is found in different locations in Nigeria, it is known in Yoruba as “Ewuro”, in Effik as “Etidot”, in Igbo as “Onugbu”. It is commonly used in traditional medicine for various purposes. Leaf decoctions are used to treat fever, malaria, diarrhea and diabetes. It can also be used as laxatives (Abosi and Raseroka, 2003).
Walnut single is an edible single seeded stone fruit botanically called ‘Tetracarpidium conophoram ‘.It provides commercial, aesthetic, and nutritional value for human beings, while also providing value for the ecosystem in terms of offering a habitat and nourishment for many animals. The fruit can be quite nutritious for people, being an excellent source of omega -3 fatty acids and various vitamins, minerals, proteins, fiber, plant sterols, antioxidant and has been shown to be helpful in lowering cholesterol, among other health benefit (Martinez et al., 2010) .The wood of some species of walnut is highly prized for its color and hardness, being used for furniture and other purposes. (wang and wegiel , 2004)
1.1 Justification: To assess the anti diabetic effect of bitter leaf, walnut and their combination on wistar albino rats induced with type 1 diabetics.
1.2 Aim: To assess the anti diabetic effect of leaves extracts.
1.3 Objectives
- To assess the anti diabetic effect of bitter leaf on wistar albino rats.
- To assess the anti diabetic effect of walnut on wistar albino rats.
- To assess the anti diabetic effect of bitter leaf and walnut combination on wistar albino rats.
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1 Diabetes mellitus
Diabetes is one of the oldest diseases of human kind whose devastating effect is increasing by the day and severity almost at epidemic level (wide, et al., 2004). It is a disease of disordered metabolism of carbohydrate, that also affect protein and fat which is caused by complete or relative insufficiency of insulin action (mycek, 2000). There are three types of diabetes; two are related to insulin, which regulate blood sugar levels.Type1 diabetes called insulin-dependent diabetes mellitus (IDDM) and type 2 diabetes called non-insulin dependent diabetes mellitus (NIDDM) are related to insulin while gestational diabetes (GDM) is not. The number of people with diabetes is increasing due to population growth, aging, urbanization, increasing prevalence of obesity and decrease physical activity (king and Rewers, 1993; Ramachnadran et al.,1999). The early symptoms of diabetes include elevated blood sugar levels (glycosuria), dehydration, weight loss, blurred vision.
Diabetes mellitus is a pathophysiological condition in which there is excessive glucose in the blood. It is a disease in which homeostasis of carbohydrate, protein and lipid metabolism is improperly regulated by the hormone insulin in elevation of fasting and postprandial (after-feeding) blood glucose level (Dewanjee et al., 2008; Twari and Rao, 2002). The effect of DM include long term damage, dysfunction and failure of various organs especially the eyes, kidney, nerves, heart and blood vessels (CDA,2006).symptoms of DM include polyuria, polydipsia and weight loss. Impairment of growth and susceptibility to certain infections may also accompany chronic cases while in acute, life threatening situation of hyperglycemia with ketoacidosis or non ketotic hyperosmolar state may develop leading to stupor, coma and even death in the absence of effective treatment (diabetes care, 2008).Diabetes mellitus is the commonest non-communicable endocrine disease and is considered one of the living cause of death all over the world; affecting over 135 million people worldwide (MSMR, 2004). Hyperglycemia of sufficient degree may cause pathological and functional difference which may be present for a long time before diagnosis is made (ANAGA 2003). Long-term complications of diabetes include retinopathy leading to blindness; neuropathy with risk of foot ulcer, amputation and Charcot joint: and autonomic neuropathy causing gastrointestinal, genitourinary, cardiovascular syndrome and sexual dysfunction (Kengne et al., 2005; IDF, 2005; Diabetes care, 2004). Patients with DM have an increase incidence oatherosclerotic cardiovascular, peripheral arterial cerebrovascular disease. Hypertension and abnormalities of lipid metabolism are often found with people with diabetes (Diabetes care, 2004).
2.2 AETIOLOGY AND CLASSIFICATION
2.2.1 Type 1diabetes mellitus
Interleukin 1 (IL-I) is a protein cytokine which is the principal trigger of all immune responses. This substance is produced by macrophages as a result of antigen processing. Interleukin mobilizes B and T cells and stimulates T-helper cells to produce IL-2, another cytokine important to the immune response. Most significantly,ss the pancreatic islets of animals with spontaneous diabetes have been shown to contain inflammatory cells incorporating IL-1, and incubation of islets with IL-1, selectively destroys β-cells. Moreover, development of type 1diabetes normally occurs over a period of a few weeks, and in a few instances where this was spotted very early and the patients treated with immune suppressants such as cyclosporine, the diabetic process was ameliorated. These facts indicate that type 1 diabetes probably results from an autoimmune process involving IL-1. There are a handful of cases (Menser, et al., 1978) in which viruses have been implicated in development of type 1 diabetes. One of the most convincing evidence involved a previously healthy young boy who suddenly developed very severe diabetes and died after 7 days (Pak, et al., 1988). Coxsackie B4 virus was cultured from his body fluid, which produced diabetes when injected into animals.
2.3 CAUSES OF DIABETES
2.3.1 Causes of type 1 diabetes
(a) Type 1 diabetes usually develops due to an autoimmune disorder. This is when the body’s immune system behaves inappropriately and starts seeing one of its own tissues as foreign.
(b) The islet cells of the pancreas that produce insulin are seen as the “enemy” by mistake. The body then creates antibodies to fight the “foreign” tissue and destroys the islets cells ability to produce insulin. The lack of sufficient insulin thereby results in diabetes.
(c) It is unknown why this autoimmune diabetes develops. Most often it is a genetic tendency; sometimes it follows a viral infection such as mumps, rubella, cytomegalovirus, measles, influenza, encephalitis and polio (Menser, et al., 1978). Certain people are more genetically prone to this happening although why this occurs is not known.
(d) Other less common causes of type 1 diabetes include injury to the pancreas from toxins, trauma, or after the surgical removal of the majority (or all) of the pancreas.
2.4 Type 2 diabetes mellitus
Etiology of type diabetes is less clearly understood
There are many root causes of the diseases;
(a) Impaired insulin release – basal secretion of insulin is often normal, but the rapid release of insulin is greatly impaired, resulting in failure of normal handling of carbohydrate load.
(b) Insulin resistance – A defect in the tissue response to insulin is believed to play a major role. This phenomenon is called insulin resistance and is caused by defective insulin receptors on the target cells.
There is a much stronger genetic link in this condition than in type 1 diabetes (Nurup et al., 1994, Tattersall and Pyke, 1972).
There is also a most intriguing suggestion that mutations in the gene for the enzyme glycosidase represent the genetic defect in a form of type 2 diabetes known as maturity onset diabetes of the young (MODY). This type 2-like condition is quite rare, but very strongly genetically linked in affected families.
2.4.1 Causes of type 2 diabetes
Development of type 2 diabetes seems to be multi-factorial. That is, there are a number of issues to blame.
(a) Genetic predisposition seems to be the strongest factor.
(b) Obesity and high caloric intake
(c) Twenty percent of people with this type 2 diabetes have antibodies to their islet cells, which are detectable in their blood resulting in the possibility of incomplete islet cell destruction. These patients often tend to respond early to oral drugs to lower blood sugar but may need insulin at some point.
2.5 BIOCHEMISTRY AND PATHOGENESIS OF DIABETES: ROLE OF INSULIN
Insulin is secreted in response to elevated serum glucose levels, by the β-cells of the pancreatic islets of Langerhans. Islet -cells secrete glucagons, a hormone with actions nearly opposite those of insulin, the -cells also secrete somatostatin, and the F-cells secrete pancreatic polypeptide.The role of insulin is to stimulate the GLUT-4 glucose transporter. GLUT-4 is the most important of the glucose transporter molecules and by insertion into the muscle and adipose cell membranes serves to facilitate glucose delivering into these cells.
This is the only mechanism by which glucose can be delivered to fat, muscle, and also liver cells. Under normal circumstances, liver and muscle cells take up glucose and convert any excess to the storage form glycogen. If insulin is absent, these three types of cells will undergo “starvation, in the midst of plenty”, and have to resort to last-ditch methods, once glycogen is exhausted, to obtain glucose, which is required as an energy source by the cells. Insulin is also involved in uptake of amino acids by muscle cells.
2.5.1 Complications of Diabetes
Diabetic complications include:
I. . Ocular problems
In diabetic retinopathy, the epithelia cells undergo hyperplasia, so that the basement membrane may become three times as thick as normal. This produces vascular lesions which in turn promote the growth of small, fragile blood vessels in the retina. These are easily ruptured, producing retinopathy, for which the only treatment is laser photocoagulation. Sorbitols also cause cataracts by producing an osmotic over hydration of eye tissue.
II. . Diabetic Nephropathy
Excess sorbitol causes lesions in small blood vessels similar to those seen in the eye. Hypertension appears to exacerbate the condition, and recently it has been found that angiotensin converting enzyme (ACE) inhibitors not only prevent development of diabetic nephropathy but alleviate this condition, even if systemic hypertension is not present (Lewis et al., 1993).The proposal is that ACE inhibitors reduce possible renal hyperion.
III. Atherosclerosis and other Vascular Complications
Hardening of the arteries is very apparent in diabetics, and is associated with an increased risk of stroke, heart attack, and other complications.
Blood vessel deterioration is associated with sorbitol production. Compromised circulation in the legs can lead to non healing leg ulcers with gangrene, sometimes requiring amputation of the affected limbs. Skin infections, especially those due to Candida albicans, are also commonly observed in diabetics requiring amputation of the affected limbs.
2.5.2 Role of hormones other than insulin in diabetes
i. Glucagon
Glucagon is a 29-residue peptide, produced by the -cells of the pancreas. The role of glucagon is to prevent hypoglycemia. It interacts with specific receptors in liver to trigger glycogenolysis and an increased in gluconeogenesis through cAMP related events. It is thought that glucagon antagonist may be helpful in reducing serum glucose levels in type 2 diabetes (Livingstone and Schoen,1999).
ii. Somatostatin
It is produced by the -cells of the pancreas and is known to affect the release of other pancreatic hormones. It inhibits the release of other pancreatic hormones like. It inhibits the release of both insulin and glucagon, and when administered to untreated diabetic patient ameliorates elevation in both the postprandial and fasting serum glucose levels. It has also been shown that administration of somatostatin causes a reduction in the dose of insulin necessary to maintain type 1 diabetic patients.
iii. Pancreatic Polypeptide
These small peptides, also produced by the pancreas, appear to have a role in the control of insulin secretion and possibly of glucose metabolism.
2.6 ANTI-DIABETIC AGENTS
2.6.1 Anti-diabetic herbs
Despite the significant achievements in treatment modalities and preventive measures of diabetes, its prevalence has risen exponentially in the last decade. Because of these limitations, there is continued need for new and more effective therapies which would improve diabetic control and reduced associated risk factors like hyperlipidemia, and hypertension. A lot of alternative therapies have emerged with herbal medicine inclusive. This is why the use of herbs has more than tripled over the last ten years (Eisenberg et al., 1988).
The field of herbal medicines research has gained significant importance in the last few decades and the demand to use natural products in the treatment of diabetes is increasing worldwide. Available literature reports shows that there are more than 400 plant species showing antidiabetic activity (Rai 1995; Mukherjee, 1981). The effects of these plants have been shown to delay the development of diabetic complications and correct some metabolic abnormalities. In the past few years some of the new bioactive drugs isolated from hypoglycemic plants showed antidiabetic activity with more efficacy than oral hypoglycemic agents used in clinical therapy (Mahamed et al., 2006). Moreover, a large number of medicinal plants possess some degree of toxicity. For example, it was reported that about one third of medicinal plants used in the treatment of diabetes are considered to be toxic (Marles and Fransworth, 1994).
significantly suppressed the rise in peripheral glycemia, both in the basal (fasting) state and after glucose intake (rats rendered glucose intolerant by tetracycline-induced fatty liver). Suppression of basal blood glucose output indicated a lowering effect of the plant extract on hepatic glucose output (Nicola et al., 1996). Single doses of unroasted seeds of Cajanius cajan Mill sp. (Pigeon Pea) caused a significant reduction in serum glucose levels 1-3 h after oral administration to healthy and alloxanized mice. In contrast, roasted seeds caused a significant increase in serum glucose levels during the 3 h experimental period. This shows that roasting of seeds at high temperature for 30 min resulted in the total loss of the hypoglycaemic component (Amalraj and Ignacimuthu, 1998).
Vernonia amygdalina (bitter leaf) is a common medium sized shrub with abundant bitter principles in every part of the plant. It is a widely used local plant.
2.6.2 Anti-diabetic Drugs
Anti diabetic drugs are mediations that work to lower blood glucose concentrations, or the amount of sugar in the blood. Anti diabetic drugs exert their useful effects through:
(1) Increasing insulin level in the body.
(2) Increasing the body’s sensitivity (or decreasing its resistance) to insulin.
(3) Decreasing glucose absorption in the intestines.
The hypoglycemic effect of salicylates have been known for 100 years. The mechanism was never established with certainty, although it appears that salicylates enhance insulin secretion. Clinical use of salicylates was not feasible since the very large doses required produced intolerable side effects.
The hypoglycemic effects of the thiadiazole sulfonamide known as IPTD, used to treat typhoid fever in the 1940s were also noted. This drug produced many deaths which were subsequently attributed to prolonged drug-induced hypoglycemia. At about the same time these effects were noted, the synthesis of sulfonylureas such as carbutamide, an active hypoglycemic agents was reported (Groop, 1992). Since then about 12,000 sulfonylureas have been tested, and about 10 are currently on the market (Groop, 1992).
The hypoglycemic effects of guanidine were reported in 1918 but toxic effects prevented its use. The guanidine derivatives synthalin A and synthalin B were introduced into therapy in the 1929s, but chronic toxicity forced their abandonment in the 1930s. The widely used biguanides phenformin and metformin were prepared in the 1950s, and the later is still in widespread use. Other classes of hypoglycemic agents, the thiazolidinediones, have been introduced more recently.
In the long history of the world, plants have been used medicinally. A large and increasing number of patients use medicinal herbs or seek the advice of their physician regarding their use (‘O’ Hara et al., 1998). It has been estimated roughly, that presently more than half of the total population of the world use herbal drugs (Chang, 1987). Increasing interest in medicinal herbs has increased scientific scrutiny of their therapeutic potentials and safety thereby providing physicians with data to help patients make wise decisions about their use (‘O’ Hara et al, 1998).
2.7. Botanical profile of Vernonia amygdalina Del.
2.7.1 Taxonomy
Kingdom: Plantae
Phylum: Angiosperm
Class: Eudicots
Order: Asterales
Family: Asteraceae
Genius: Vernonia
Species: V. amygdalina
Figure 2: Vernonia amygdalina in its natural habitat
In many parts of Africa the plant is variously known as ‘Grawa’ in Amharic, ‘Ewuro’ inYoruba, ‘Etidot’ in Ibibio, ‘Onugbu’ in Igbo, ‘Ityuna’ in Tiv, ‘Oriwo’ in Edo and ‘Chusardoki’in Hausa (Egedigwe, 2010).
2.8.2 Description
Figure 2.1 :vernonia amygdalina (singha,1966)
Vernonia amygdalina Del. (family of Asteraceae) is a valuable medicinal plant that is widespread in East and West Africa (Ainslie, 1973; Burkill, 1985). It is a perennial shrub of 2-5m in height that grows throughout tropical Africa. It has a rough bark with dense black straits, and elliptic leaves that are about 6 mm in length. The leaves are green and have a characteristic bitter taste which makes it to be commonly referred to as bitter leaves (Singha,1966).
2.8.3 Geographical Distribution
In many parts of West Africa, the plant has been domesticated (Igile et al., 1994). V.amygdalina is drought tolerant (though it grows better in a humid environment). It thrives on a range of ecological zones and is used as a hedge plant in some communities (Bonsi et al.,1995).
2.8.4 Ethnomedicinal Uses
The roots and the leaves are used in ethnomedicine to treat fever, hiccups, kidney problems, and stomach discomfort (Burkill, 1985; Hamowia and Saffaf, 1994). The stem and root divested of the bark are used as chew-sticks in many West Africa countries like Cameroon, Ghana, and Nigeria. V. amygdalina leaves are one of the most widely leaf vegetables (ndole or bitter leaf) consumed by Nigerians and Cameroonians during special occasions such as marriages, baptisms, Christmas, and birthday.
2.8.5 Documented research findings on V. amygdalina
Pharmacological studies have shown that the leaf extracts of V. amygdalina have both hypoglycemic and hypolipidemic properties in experimental animals and so could justify their use in managing diabetes mellitus by local healers (Akah and Okafor, 1992). It has been reported to have anticancer activity (Izevbigie, 2003), anti-bacteria, antimalaria, and antiparasitic activities (Tadesse, 1993). The beneficial use of V. amygdalina in animal nutrition in Nigeria has been well documented (Onwuka et al., 1989; Aregheore et al., 1998). It was reported that V.amygdalina leaf extract enhanced the prophylactic and therapeutic efficacy ofchloroquine against Plasmodium berghei malaria in mice (Iwalokun, 2008). Published studies indicate that V. amygdalina have medicinal properties effective against many diseases other than breast cancer. The molecular mechanisms under which this compound exerts its therapeutic effect in cancer cells have also been reported (Izevbigie, 2003; Izevbigie et al.,2004). Reports indicate that extracts from planpoiuts are able to inhibit and even reverse carbon tetrachloride-induced hepatotoxicity in mice and rats (Ijeh et al., 1996; Babalola et al., 2001).
V. amygdalina Del. has been shown to contain significant quantities of lipids (Ejoh et al.,2007; Eleyinmi et al., 2008), proteins with high essential amino acid score (Igile et al., 1994;Udensi et al., 2002; Ejoh et al.,2007; Eleyinmi et al., 2008) that compare favorably with values reported for Telfairia occidentalis and Talinum triangulare (Ijeh et al., 1996), carbohydrates (Ejoh et al.,2007) and fiber (Udensi et al., 2002; Ejoh et al., 2007; Eleyinmi et al., 2008). The plant has also been shown to contain appreciable quantities of ascorbic acid and caroteinoids (Udensi et al.,2002; Ejoh et al., 2007). Calcium, iron, potassium, phosphorous, manganese, copper and cobalt have also been found in significant quantities in
V. amygdalina (Bonsi et al., 1995; Ejoh et al., 2007; Eleyinmi et al., 2008).
Documented pharmacological properties of V. amygdalina.
1. Antibacterial Methanol (60%) Akinpelu (1999) Crude extract Ijeh et al. (1996) Ethanol Erasto et al. (2006)Jisaka et al. (1993b).
2.Antiplasmodial/antimalarial Aqueous Njan et al. (2008) Aqueous Iwalokun.(2008) Ethanol Abosi and Raseroka (2003)- Masaba (2000).
3. Amoebicidal Moundipa et al. (2005) Huffman et al. (1996).
4. Antifungal Aqueous Alabi et al. (2005) Ethanol Erasto et al. (2006) Wedge et al. (2000).
5. Antileishmanial Chloroform andmethanolTadesse et al. (1993) - Huffman et al. (1996).
6. Antischistosomial Ogboli et al. (2000).
7 .Wound management Crude extract Giday et al. (2003)
8. Anti-Cancer/Tumor Oyugi et al. (2009)Chloroformic Kupchan et al. (1969)
Aqueous Yedjou et al. (2008) Aqueous Gresham et al. (2008)Aqueous Izevbigie (2003) (2004)Aqueous Howard et al. (2006) Aqueous and ethanol of root cultures Khalafalla et al., (2009)Jisaka et al., (1993b).
9. Venereal disease management Kambizi and Afolayin(2001).
10. Antioxidant Aqueous and ethanolic Owolabi et al., (2008).
Methanol (30%) Igile et al., (1994) Aqueous Nwanjo, (2005)Methanol Adaramoye et al. (2008)- Iwalokun et al., (2006).
11. Hypoglycemic/Antidiabetic Ethanol Ekpo et al. (2007) Aqueous Osinubi (1996) Aqueous Nwanjo and Nwokoro,(2004)Aqueous Akah and Okafor (1992)
Aqueous Uhuegbu and Ogbechi,(2004)Crude extract Atangwho et al. (2007).
12. Oxytocic Aqueous Kamatenesi-Mugisha(2004)Aqueous Kamatenesi-Mugisha et al.(2005)
13.Hepatoprotection Aqueous Arhoghro et al. (2009)Diet incorporation Ijeh and Obidoa (2004)- Babalola et al. (2001)Iwalokun et al. (2006)
14. Nephroprotection Ethanol Atangwho et al. (2007) Ethanol (80%) Atangwho et al. (2009a)
15. Serum lipid modulation Diet incorporation Egedigwe (2010) Diet incorporation Ugwu et al. (2010) Methanol Adaramoye et al. (2008)Ethanol Ekpo et al. (2007)Aqueous Nwanjo (2005)s- Ezekwe and Obidoa (2001)
16. Gastric secretion Aqueous Owu et al. (2008)
17. Analgesic Aqueous Njan et al. (2008)
18. Anti-fertility Root extract Steen-Kamp (2003)- Desta (1994)
19. Insecticidal Dust Kabeh and Jalingo (2007) Oil Asawalam and Hassanali(2006)
20. Phytotoxic Alabi et al.(2005).
The forest of some African countries is blessed with a wide range of wild oil-bearing seeds and nuts which have not been evaluated for their nutritional potentials and or toxicity risk. One of such botanicals is Tetracarpidium conophorum(walnut).T. conophorum (Mull. Arg.)Hutch. & Dalz (Euphorbiaceae), known as conophor (English), ukpa (Igbo- Eastern Nigeria ), awusa or asala(Yoruba-Western Nigeria), is a perennial climbing shrub of 3-6m long. The plant is glabrous with deciduous male flowers, leaving the females at the base of the raceme. In African, T. conophorum is known as Africa Walnut where it is found in the forest regions of Africa and india (Petrova,1980). In Nigeria, it is found in Uyo, Etinam, Akpabuyo, Lagos and Ibadan. The plant is cultivated principally for the nuts which are cooked and consumed as snacks (Oke, 1995). The leaves are used as male fertility agent and n the treatment of dysentery in southern Nigeria. The oil from the nut could serve as a source of energy for growing seedlings and has been reported to be used in the formulation of wood varnish, stand oil and vulcanized oil(Ajaiyeoba and Fadare, 2006). T.conophorum kernels which have high lipid content are often eaten as nibbles in Cameroon (Tchiegang et al., 2001).
Figure 2.2:Tetracarpidium conopphorm (MartÃnez et al., 2010)
Previous studies focused on the nutritive value of the seeds (Oke and Fafunso, 1975; Adebona et al., 1988; Akpuaka and Nwankwo, 2000), chemical and functional characteristics of conophor nuts (Enujiugha 2003), antimicrobial, chelating and antidiabetic activity of the extracts and fractions of the nut (Ajaiyeoba and Fadre, 2006). Recently, physiochemical characteristics of the nut oil revealed that the oil is edible and a good candidate for conventional oil ; the plant is medicinal and used for various purposes, including masticatory, giddiness, thrush, antihelminthic, toothache, syphilis, dysentery and as antidote to snake bite. (Oladiji et al.,2007).
The seeds of Juglans regia L.(Juglandaceae), are a highly nutritious food (MartÃnez et al., 2010). They are also used as a traditional therapy for treating cough, stomach ache (Perry, 1980) and cancer in Asia and Europe (Duke, 1989). Walnut fat is mostly unsaturated fatty acids, such as linoleic and oleic acid,which may give walnuts additional antiatherogenic properties (Fukuda et al., 2003; Feldman, 2002). Walnuts are highly enriched in omega-6 and omega3 polyunsaturated fatty acids (PUFA), which are essential dietary fatty acids. Epidemiological and clinical trials suggest that omega-3 PUFA might have a significant role in the prevention of coronary heart disease (CHD)(Harper and Jacobson, 2001; Bucher et al., 2002).
Walnut consumption improves endothelial function in type2 diabetic individuals and may therefore help reduce cardiovascular disease risk in this high-risk population (May et al., 2010). . Furthermore, the study suggested that the oil may be used as raw material for soap, paint, food and other related industries.
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