The antianemic potential of crude methanol extract of red creole onion cultivar was investigated in phenylhydrazine-induced anaemic albino rats. LD50 of the crude methanol extract was found to be greater than 5000mg/kg/b.w. Thirty five (35) apparently healthy albino rats were grouped into seven groups of five (5) rats per group for the determination of the antianemic effect of the crude methanol extract, and groups two (II) to six (VI) were intraperitoneally administered with phenylhydrazine (10mg/kg/b.w/day) for 4 days. The study was carried out for a period of 21 days in which there was subsequent treatment of groups four (1V) to six (V1) with crude methanol extract of red creole onions at three different doses of 200,400 and 600mg/kg/b.w/day respectively, while Bioferon (0.23ml/kg/b.w) was used as a standard drug for positive control group. Haematological parametres were determined on weekly basis. Non-significant(p>0.05) increase in Hb, PCV and RBC concentrations were observed for all the treated groups at the end of the experiment, however, the RBC of the group that receives the highest dose (600mg/kg/b.w) decreased slightly after two weeks treatment with the extract. Non-significant(p>0.05) decrease in reticulocytes counts were also observed for all the treated anemic groups. The non-significant increase in all the parameters were not comparable with the standard drug (Bioferon) which shows a significant (p<0.05) increase in Hb, PCV and RBC as well as decrease in reticulocytes counts after three weeks treatment with the drug. The phytochemicals found in red creole onion extract include alkaloids, flavonoids, cardiac glycosides and phenolics. Terpenoids, Saponins and cyanogenic glycosides were absent. These results suggest that red creole onion does not possess antianaemic effect, especially as compared with the standard drug.

CHAPTER ONE

1.1   Background of the Study
Anaemia is defined as a decrease in the number of red blood cells or less than the normal quantity of hemoglobin in the blood (Iwalewa et al, 2009). However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin deficiency. Because hemoglobin normally carries oxygen from the lungs to the capillaries, anemia leads to hypoxia in organs. Since all human cells depend on oxygen for survival, varying degrees of anemia has a wide range of clinical consequences. Anaemia is characterized by excessive destruction of erythrocytes at a rate that exceeds the bone marrow’s capability to compensate for the blood loss (Holy et al, 2015).
Anaemia is one of the clinical conditions that constitute a serious health problem in many tropical countries as a result of the prevalence of different forms of parasitic infections, including malaria (Dacie and Lewis, 1994). In the tropics, due to prevalence of malaria and other parasitic infections, between 10 to 20 % of the population are reported to possess less than 10g/dl of haemoglobin in the blood (Diallo et al, 2008).
Hemolytic Anemia is an acquired type of Anemia caused by hemolysis (premature destruction of red blood cells). Autoimmune hemolytic anemia is the primary type, in which antibodies produced by the immune system damage RBCs. The causes of hemolytic anemia is sometimes unknown or associated with disorders such as systemic lupus erythematosus, lymphoma, and paroxysmal nocturnal hemoglobinuria. Other causes are high exposure to certain metals or chemicals (lead, copper, benzene, naphthalene), snake and insect bites, malaria, transfusions, post-surgical complications, and drugs such as methyldopa. In infants, blood group incompatibility between mother and child or infections in the womb can cause hemolytic anemia. As for its treatment, corticosteroids can be used for autoimmune hemolytic anemia. Blood transfusions is also beneficial in many cases. Various immunosuppressive drugs may be tried, as well as splenectomy. Eculizumab (Soliris) is approved for treatment of paroxysmal nocturnal hemoglobinuria (Alleyne et al, 2008).
Phenylhydrazine is used for the induction of haemolytic anaemia, and its mechanism of induction had been studied in many species.Phenylhydrazine and its derivative 2, 4-dinitrophenylhydrazine are toxic agents. Their toxic action has been attributed to their ability to undergo auto oxidation. This increased oxidant potential enables them to oxidize enzymes, membrane proteins and hemoglobin. Phenylhydrazine initiates lipid peroxidation in membrane phospholipids (Jain and Hochstein,1979), while 2,4-dinitrophenylhydrazine induces lipid peroxidation and other oxidative damage in rabbits (Ologundudu and Obi, 2005; Ologundudu et al, 2006a,b) and rats (Maduka et al, 2003).
Medicinal plants are useful worldwide in the treatment of diseases. Plants have provided the basis for traditional treatment for different types of disease and still offer an enormous potential source of new chemotherapeutic agents. In a recent report released by the world health organization, more than 80% of the world population still relies on herbal medicines as their primary source of health care. Millions of Africans of all ages rely on herbal medicine for primary health care (Abubakar et al, 2005).
Antianaemic effects of plants can be assessed clinically in humans, in vivo using animal models or in vitro using a variety of test systems. Preliminary testing of a herb in an animal model can give valuable information on the type of extract to be made, a suitable dose, the likely toxic effects, and of course, the efficacy. This information can then be translated to human studies, although species differences and ethical considerations may be limiting factors. Animal and human studies are essential to determine the ultimate safety and efficacy of a herb or its components when used clinically (Amala, 2006).
Onion (Allium cepa), also known as the onion bulb or common onion, is used as a vegetable and is the most widely cultivated species of the genus Allium. This genus also contains several other species variously referred to as onions and cultivated for food. Onion is most frequently a biennial or a perennial plant, but is usually treated as an annual and harvested in its first growing season (Fritsch and Friesen, 2002). Onion is easily propagated, transported, and stored. The onion (Allium cepa L.) is one of the world’s most important vegetable crops. It is grown in a wide range of climatic conditions, from relatively hot and dry areas to fairly cool and humid zones (Tindall, 1983, Messiaen, 1992). Because of its distinctive pungent flavour, the onion is used almost daily as an essential seasoning for a wide variety of dishes and it is, therefore, a major trading vegetable commodity in all urban and rural centres.
Members of the same onion cultivar produces bulb of the same size (either small or big sizes),same texture, same flavour (stronger or mild pungent ),same keeping or storing quality, and same shape (either oblate, flat or globular) (Abdalla, 1987). Red, white and yellow are the most common bulb colours observed. Different cultivars can differ in terms of some phytochemicals and active components, for example, all onion cultivars contain quercetin, which is effective in reducing the risk of cardiovascular disease, an anticancer, and an antioxidant, however, there is difference in quecetin levels between cultivars with red and yellow onions having higher concentrations and white having a low concentration (Currah and Proctor 1990).
In Nigeria, the onion producing states are Kano, Kaduna, Jigawa, Sokoto, Plateau, Bauchi and Kebbi states, with Alieru town in Kebbi considered as onions home in Nigeria (Irabor, 2014). The onion cultivars in the northern part of the country include Kaharda, Red creole, koumassa, maikanmakwarwa, Sokoto local (Abubakar and Ado, 2013), Kano red, Kano white, Gindin tasa, Wuyan makorowa, Yar yawuri, Fara, Hauke, and Doguwa (Garba, et al, 2011).In North-eastern part of the country however, only five specie are popular, and they include: Red globe (crayon),Sweet Spanish, Yellow globe, Spring or Scallion and White globe (Ibrahim, 2010).
Red creole onion is a slightly pungent, spicy, purple red onion which is excellent for storing. It originates from united state and it produces mainly single onion with hard, flat and round bulb which is good for cooking or in salads. It is a medium size onion and it does well in hot-dry climate as well as different extremes of cold temperature (Babasaheb, 2004).
Consumption of onions is believed to benefit health in that onions contain phenolics and flavonoids, although most often not used specifically as a medicinal herb, the onion has a wide range of beneficial actions on the body and when eaten (especially raw) on a regular basis will promote the general health of the body. The bulb is antihelmintic, antibiotic, anti-inflammatory, anti-microbial, antirheumatic, antiseptic, antispasmodic, depurative, diuretic, expectorant, fungicidal, hypocholesterolemic, hypoglycemic, hypotensive, stomachic, stimulant, antiviral, antibacterial, tonic, among others, and it may be used both internally and externally for medicinal purposes (Gupta, 1994).

1.2    Statement of Research Problem
The incidence of anaemia is higher in the third world than in developed countries due to the presence of many aggravating factors such as poor nutrition, and high prevalence of blood parasites example, Plasmodium, trypanosomes and helminthes infestation (Ogbe et al, 2010). Anaemia prevalence remains high in Africa, with an overall incidence of 57% among pregnant women, 48% among non-pregnant women and 68% among preschool children (WHO, 2011). This indicates that women are more susceptible to anaemia during pregnancy due to high demand from the developing foetus (Orna, 1991).
Although there are various drugs used for the treatment of anaemia, they are not affordable to many poor people especially those in the developing countries such as Nigeria. In addition, the rural populations in various parts of the world do not have adequate access to high quality drugs for the treatment of anaemia, so they depend heavily on plants and herbal products for the treatment of many diseases including anaemia. Due to the fact that anaemia is very common and the incidence is likely to increase in future (Duff, 2008), there is need to prevent it or seek for more cost-effective and better treatment strategies.

1.3    Justification of the Study
Anaemia is the most common blood disorder in developing countries, and according to a study more than 30% of the world population experience some degree of anemia in their life time. The people at greater risk are the elderly, young women of child-bearing age, and the infants (WHO, 2008).
In Nigeria, prevalence of anaemia among women of reproductive age (15- 49 ) was 48.50 %, while that of children under five was 71.00% as of 2011 (WHO, 2011). Recently, in her media conference in Lagos, the Nutritional Society of Nigeria (NSN) revealed that 72% of Nigerian children are anaemic (NSN, 2015).
Onions are known to possess many curative value rights from the ancient time. Recently, some natural nutritionist claimed that onions and juice of onion stalk are good herbal medicine for the treatment of anaemia. Example, according to Rudy S. (2010), onion stimulates blood formation and improves haemoglobin level. Also, Oluwaseun (2015), claimed that eating onions aids in the treatment of anaemia.
A survey of literature revealed that no scientific approach has been made to back this up. Hence the challenge of this investigation is to assess the antianaemic potential of red creole onion cultivar so as to validate the ethnotherapeutic claim. Red creole onion cultivar was choosen because it is a popular standard variety in high demand due to its good keeping quality (Kuepper, 2014 ).

1.4    Aim and Objectives
The general aim of this research work is to evaluate the anti anaemic effect of
methanol extract of red creole onion (Allium cepa) in phenyl- hydrazine induced anaemic
rats. The specific objectives are to:

1. identify and quantify some of the phytochemical constituents of the crude extract.
2. assess the antianaemic potential of the crude methanol extract of red creole onions.
3. establish the fraction of the crude methanol extract that has the highest antianaemic potential.
4. characterize the most active fraction of the methanol crude extract.