Effect of ethanol extract of annona muricata leaves on alanine aminotransferase and aspartate aminotransferase activity of albino rats

COMPARATIVE ANALYSIS OF VITAMIN C IN FRESH FRUITS JUICE OF Malus domestica, Citrus sinensi, Ananas comosus AND Citrullus lanatus BY IODOMETRIC TITRATION

Introduction

Vitamin C or L-ascorbic acid, or simply ascorbate (the anion of ascorbic acid), is an essential nutrient for humans and certain other animal species. Vitamin C refers to a number of vitamers that have vitamin C activity in animals, including ascorbic acid and its salts, and some oxidized forms of the molecule like dehydroascorbic acid. Ascorbate and ascorbic acid are both naturally present in the body when either of these is introduced into cells, since the forms interconvert according to pH. Vitamin C is a cofactor in at least eight enzymatic reactions, including several collagen synthesis reactions that, when dysfunctional, cause the most severe symptoms of scurvy (Food standards agency, 2007). In animals, these reactions are especially important in wound-healing and in preventing bleeding from capillaries. Ascorbate may also act as an antioxidant against oxidative stress (Padayatty et al., 2003). However, the fact that the enantiomer D-ascorbate (not found in nature) has identical antioxidant activity to L-ascorbate, yet far less vitamin activity (Aboul-Enein et al., 1999) underscores the fact that most of the function of L-ascorbate as a vitamin relies not on its antioxidant properties, but upon enzymic reactions that are stereospecific. “Ascorbate” without the letter for the enantiomeric form is always presumed to be the chemical L-ascorbate. Ascorbate (the anion of ascorbic acid) is required for a range of essential metabolic reactions in all animals and plants. It is made internally by almost all organisms; the main exceptions are most bats, all guinea pigs, capybaras, and the Anthropoidea (i.e., Haplorrhini, one of the two major primate suborders, consisting of tarsiers, monkeys, and humans and other apes). Ascorbate is also not synthesized by some species of birds and fish. All species that do not synthesize ascorbate require it in the diet. Deficiency in this vitamin causes the disease scurvy in humans (Food standards agency 2007; University of Maryland Medical Center 2007; Higdon et al 2006). Ascorbic acid is also widely used as a food additive, to prevent oxidation. Fruit is a part of a flowering plant that derives from specific tissues of the flower, one or more ovaries, and in some cases accessory tissues. Fruits are the means by which these plants disseminate seeds. Many of them that bear edible fruits, in particular, have propagated with the movements of humans and animals in a symbiotic relationship as a means for seed dispersal and nutrition, respectively; in fact, humans and many animals have become dependent on fruits as a source of food (Lewis and Robert, 2002). Fruits account for a substantial fraction of the world’s agricultural output, and some (such as the apple and the pomegranate) have acquired extensive cultural and symbolic meanings.

In common language usage, “fruit” normally means the fleshy seed-associated structures of a plant that are sweet or sour and edible in the raw state, such as apples, oranges, grapes, strawberries, bananas, and lemons. On the other hand, the botanical sense of “fruit” includes many structures that are not commonly called “fruits”, such as bean pods, corn kernels, wheat grains, and tomatoes (Schlegel and Rolf, 2003; Mauseth and James, 2003). Apple (Malus domestica) 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 deciduous trees which are large if grown from seed, but small if grafted onto roots (rootstock).

The need to evaluate students after an effective teaching and learning process is necessary. To this end, educationists have introduced a method of evaluation known as continuous assessment, which forms an integral part of Nigeria’s new policy on education, published in 1977 and revised in 1981, 1983, 1987, 1989 and 2014. The new policy stipulates among other things, the use of continuous assessment for students evaluation instead of using the orthodox single end of course, of year, national or certificate examinations. According to National Policy on Education (2014) the primary education will have the duration of six years, secondary education for six years, which is further sub-divided into three years Junior Secondary School (JSS) and three years of Senior Secondary School (SSS). It enables students to acquire further knowledge and develop skills. The Senior Secondary School is for those willing to have a comprehensive education with a core curriculum designed to broaden students’ knowledge and outlook and large number of effective subjects for a choice of career.

This new policy started from 1982/1983 Academic Session. In 1976, Universal Free Primary Education (UPE) was introduced, Also in 1999 the Universal Basic Education (UBE) programme was launched and executed by the Government and people of the Federal Republic of Nigeria to eradicate illiteracy, ignorance and poverty as well as stimulate and accelerate national development, political consciousness and national integration. The programme was flagged off in Sokoto, Sokoto State. The Universal Basic Education programme is Nigeria’s programme strategy for the achievement of Education for All (EFA) and the education related Millennium Development Goals (MDGs.

The implementation process of the programme has been on since 1999 but progress was hampered by lack of an enabling law to execute certain aspects of the programme. What a big relief it was when the President of the Federal Republic of Nigeria, Chief Olusegun Obasanjo signed the Universal Basic Education Bill into Law on 26^th May, 2004, following its passage by the National Assembly. The Universal Basic Education Act 2004 makes provision for basic education. The financing of basic education is the responsibility of States and Local Governments. However, the Federal Government has decided to intervene in the provision of basic education with 2% of its Consolidated Revenue Fund. For States to fully benefit from this fund, criteria were established which States are to comply. The Act also provides for the establishment of Universal basic Education Commission (UBEC) to coordinate the implementation of the programme at the States and Local Government Areas through the State Universal Basic Education Board (SUBEB) of each State and the Local Government Education Authorities (LGEAs). The Universal Basic Education Commission (UBEC) was formally established on 7^th October, 2004. Furthermore the new policy on education popularly known as the 6-3-3-4 systems came into being. To this end most states in Nigeria desired to train teachers to be able to meet with new challenges in education but unfortunately enough trained teachers have not been available to man the education industry. The new policy on education (6-3-3-4) system concerned itself with qualified and dedicated teachers because of the emphasis on the use of continuous assessment.

• Conceptual Background

Greaney (2001) defines assessment as any procedures or activity that is designed to collect information about the knowledge, attitude or skills of the learner or group of learners. Assessment is therefore a process through which the quality of an individual’s work or performance is judged. When carried out as an on-going process, assessment is known as Continuous Assessment (CA). CA is a formative evaluation procedure concerned with finding out, in a systematic manner, the over-all gains that a student has made in terms of knowledge, attitude and skills after a given set of learning experience (Ogunniyi, 1984). According to Aggarwal (1999), CA is not simply continuous testing. Continuous assessment does not solely depend on formal tests. CA is more than giving a test, it involves every decision made by the teacher in class to improve students’ achievement. CA may take different forms such as formal questions given to students during class, take-home assignments/exercises and recapitulation exercise.

Assessment is either internal or external. Internal assessment refers to school-based assessment. Which includes class assignments, teacher-made tests, recap exercises and field studies, all these tools form part of the classroom continuous assessment strategies. A continuous assessment strategy refers to the different tools/procedures used in the classroom to understand the academic achievement levels of learners in terms of their knowledge, attitudes and values. Also, a strategy in assessment is a purposefully conceived and determined plan of action. It is a pattern of assessment that seems to attain certain outcomes and to guard against others (Aggarwal, 1999). External assessment refers to test that are produced by examining bodies away from school.

Isolation and identification of some bacterial species in well water in dutsin-ma metropolis