**1. Introduction**

Diabetes mellitus (DM), often simply referred to as diabetes, is a group of metabolic diseases in which a patient has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced. This high blood sug‐ ar produces the classical symptoms of polyuria (frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger). It is characterized by hyperglycaemia due to de‐ fective insulin action, insulin secretion or both. Several medicinal plants are used in the management of diabetes mellitus (Akah et al., 2002). According to the World Health Organi‐ zation (WHO), there are approximately 160,000 diabetics worldwide, the number of diabet‐ ics has double in the last few years and is expected to double once again in the year 2025 (Beretta, 2001). Due to its high prevalence and potential deleterious effect on a patient physi‐ cal and psychological state, diabetes is a major medical concern (Macedo et al., 2002). The disease remains incurable and can only be controlled with drugs. The three main types of diabetes mellitus (DM) are: Type 1 DM results from the body's failure to produce insulin, and presently requires the administration of insulin for treatment (Lambert et al., 2002). It is also referred to as insulin-dependent diabetes mellitus (IDDM) or "juvenile" diabetes). Type 2 DM results from insulin resistance, a condition in which cells fail to use insulin properly, sometimes combined with an absolute insulin deficiency (Boussageon et al., 2011). It is for‐ merly referred to as noninsulin-dependent diabetes mellitus (NIDDM) or "adult-onset" dia‐ betes). Gestational diabetes occurs when pregnant patient, who have never had diabetes before, have a high blood glucose level during pregnancy. It may precede development of type 2 DM (Sattar et al., 2010).

© 2014 Adedapo et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Several plants have been used in folkloric medicine for the treatment and prevention of in‐ fectious and non-infectious diseases in man and his animals and this has led to renewed sci‐ entific interest in the use of plants for these purposes (Oridupa et al. 2011). There is global resurgence in the use of herbal preparations and in some developing countries like Nigeria; it is being gradually integrated into the primary and secondary health care systems. Nearly all societies have used herbal materials as sources of medicines and the development of these herbal medicines depended on local botanical flora (Adedapo et al., 2009).

**2.2. Animals**

**2.3. Chemicals**

al., (2006).

so used in this study.

**2.5. Acute toxicity test**

within this period of time was recorded.

**3. Antidiabetic studies**

**3.1. Hypoglycaemic activity test**

**2.4. Phytochemical screening**

The animals used in this study were male Wistar rats weighing between 100 and 200g as well as mice weighing between 15 and 30g. They were maintained at the Experimental Ani‐ mal House of the Faculty of Veterinary Medicine, University of Ibadan in rat cages and fed on commercial rabbit cubes (Ladokun and Son Livestock Feeds, Nigeria Ltd). The animals were allowed free access to clean fresh water in bottles *ad libitum*. All experimental protocols were in compliance with University of Ibadan Ethics Committee on Research in Animals as

The Antidiabetic Activities of the Aqueous Leaf Extract of Phyllanthus Amarus in some Laboratory Animals

http://dx.doi.org/10.5772/57030

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Alloxan used in this study was obtained from Sigma-Aldrich (Chemie Gmbh, Steinheim, Denmark). The standard drug used in the various experiments was glibenclamide. The chemical and drug used were of analytical grade. Normal saline and distilled water were al‐

The phytochemical analysis was performed on the ground (powered) leaf of *P. amarus* for identification of the constituents. The constituents tested for were alkaloids, tannins, sapo‐ nins, anthraquinones, cardiac glycosides and flavonoids as described by Trease and Evans (1983); Abate (1989); Shale et al., (1999); Evans, (2002); Moody et al., (2006) and Sawadogo et

The acute toxicity of *P. amarus* aqueous was determined in mice according to the method of Hilaly *et al.* (2004) with slight modifications. Mice fasted for 16 h were randomly divided in‐ to groups of six mice per group. Graded doses of the plant's extract (100, 200, 400, 800 and 1600 mg/kg p.o.) were separately administered to the mice in each of the groups by means of bulbed steel needle. All the mice in the groups were then allowed free access to food and water and observed over a period of 48 h for signs of acute toxicity. The number of deaths

The hypoglycaemic effect of the aqueous extract was studied in alloxan-induced diabetic rats. The rats were fasted for 8 hours but allowed free access to water. At the end of the fast‐ ing period, the basal fasting blood glucose (FBG) level of the rats was determined. Subse‐ quently, diabetes was induced by single intraperitoneal injection of alloxan monohydrate (70 mg/kg) (Aruna *et al.,* 1999) and normal feeding maintained thereafter. Five days later,

well as internationally accepted principles for laboratory animal use and care.

*Phyllanthus amarus* belongs to the family Euphorbiaceae (the spurge family) of which the largest genus is the genus Euphorbia. The plant is known to originate from Malaysia. The species *Phyllanthus amarus* is a small tropical herb, which occurs widely as a rainy-season weed throughout the hotter parts of India (Bagchi et al., 1992). The widespread usage of this herb has prompted several investigations (Calixto et al., 1998; Odetola and Akojenu, 2000; Adeneye et al., 2006). The plant has a history of use in Ayurverdic medicine for over 2000 years as well as a wide variety of traditional applications. The plant is commonly found in Southern Nigeria, Sierra Leone and Equatorial Guinea. It also occurs in Ghana and other parts of tropical Africa (Irvine, 1930; Adedapo et al., 2005). It is a weed of cultivated land and in waste spaces, it is common to find it growing and spreading freely along the road sides, under flower beds and in many other places (Burkill, 1994). For this reason, grazing animals are prone to consuming this plant along with their feed particularly in drier tropical climates where lush green grass is not often available (Adedapo, 2002).

Many studies have thus been carried out on the plant in various parts of the world but there is a resurgence of interest in this plant as antidiabetic agent. The present study was therefore undertaken to investigate the phytochemical constituents, anti-diabetic and safety potentials of the aqueous leaf extract of *Phyllanthus amarus* Schum in experimental animals especially that diabetes has assumed a global dimension as a non-communicable disease.
