THE EFFECTS OF AQUEOUS, METHANOL AND PETROLEUM ETHER EXTRACTS OF XYLOPIA AETHIOPICUM ON ISOLATED RAT ILEUM
TABLE OF CONTENT
List of tables
List of figures
Introduction and literature review
Discussion and conclusion
- The effects of Aqueous, methanol and petroleum ether extracts of Xylopia aethiopicum were examined on acetylcholine (10-7 – 10-4m) – induced contractions of the rat ileum.
- The extracts shifted the acetylcholine (Ach) dose – response curves to the right.
The extracts caused an increase in the acetylcholine contraction required to produce 50% contractile response (PE2) and a significant decrease of the maximal contractile response.
- The extracts inhibited spontaneous activity induced by histamine (10-7– 10-4m).
- The extracts also significantly reduced contractions induced by potassium chloride (4 x 10-2m KCL).
- When the antispasmodic activities of the plant extracts were compared with the activity of atropine, the effect of aqueous extract was less than that of Atropine. The effects of petroleum ether and methanol extracts were comparable to that of Atropine (10-8, 10-9m).
During the last fifty years, organic chemists have synthesised a large number of interesting chemical substances, many of which have proved useful in the treatment of diseases. This has been hailed as a therapeutic revolution.
From the beginning of life, man has always been faced with problems of curing diseases. As a result of this man has always dependent on substances with his environment for help.
In most parts of the world today, especially the remote jungles of Africa, the inhabitants depend on the curative abilities of plants for the amelioration of numerous diseases.
- Given time, the most important aspect of research would consist of investigating all reputed therapeutic values ascribed to plants by herbalists. Many plants are used by different herbalists for different diseases and at times, the same plants are used for complaints all illnesses – which in orthodox medicine it would seem to require different medicines for these –opposite effects. For example, Xylopia aethiopicum, a local condiment is reported to be useful in the treatment of constipation and of dysentery and diarrhoea.
Xylopia aethiopicum, (Dunal) A. Rich is commonly known as African pepper, (cooper and Record, 1931; Dalziel, 1937) or Ethiopian pepper (Dalziel, 1937; Dliver, 1960).
In Nigeria, it is found all over the southern rain forest regions. Different names have been given to it by different regions or states for example Oda, Uda in Ibo (Dalziel, 1937), eeru in Yoruba, Unien in Edo and Okada in Rivers.
The tree which is widely distributed all over Africa in deciduous forest zones, belongs to the family Annonaceae. The trunk is smooth, grey bark, odourous when fresh and it has short prop roots. The thick fibrous bark peels readily and yields a cudage. The bark is also used in making doors and partitions, and in Gabon to wrap around torches.
The wood is white or yellowish-brown in the heart and fairly hard. Except in Sierra Leone, where it is said to be of no commercial application because it is light and brittle, in other places it is heavily, strong and elastic, and hence used for purposes requiring resilience such as the construction of boats, masts, oars, paddles and spars,. In Togo and Gabon, it is used for bows and cross bows for hunters.
The wood is resistant to termite attack and is used in hut construction for posts, roofs, ridges and joints. In the equatorial region, pieces of the bark are added to palwine merely as a flavourer, (Dalziel, 1937; Burkhill, 1985).
A fluid extract of the bark is reported to be useful in the treatment of bronchitis and dysenteric conditions and also as a medicine for biliousness (Dalziel, 1937).
In Congo, the bark is steeped in palm wine which is given for attacks of asthma, stomach-aches and rheumatism at the rate of one of two glasses per day (Burkhill, 1985).
The roots of this plant are also useful. According to Burkhill (1985), the root wood can be used as a cork. Again, the root is strongly aromatic and a concentrated root decoction is used as a mouth-wash for toothache in Senegal. The root is also powdered and used as a dressing for sores and to rub on gums for pyorrhoea and in local treatment of cancer in Nigeria. Wh3en mixed with salt it is a cure for constipation. The powder is also dusted into ulcers, and a decoction of this leaves and roots is a general tonic in Nigeria for fevers and debility.
The leaves are pungent and have pointed pubescent hairs on the under surface. In Gabon they constitute a decoction used against rheumatism. And used in friction on the chest for bronchio-pneumonia. The leaf sap – mixed with kolanut is given at the time of epileptic fits with a suitable prayer and offspring’s (Burkhill, 1985). The flowers are greenish-white with the buds long and pointed (kenedy, 1932).
Records have shown the fruit to be the most important part of the tree (Burkhill, 1985). The fruit is being used by different countries in different ways. They are narrow, slightly torulose, dark-brown or black about 5cm long, borne (separate carpels) together on a stout peduncle.
Exported to Europe in the middle ages as a pepper, they are used as flavouraer and spice and similarly used in Great Britain for medicine (Dalziel, 1937; Burkhill, 1985). In some areas like Benin, they crush the fruit to anoint their bodies. The fruits is also used to season the food of epileptic patients. The fruits has also been useful medicinally as a cough medicine, a carminative, purgative and revulsive to counter pain for example to the Yoruba ‘’Agbo’’ of which it is a very common ingredient. In Liberia the paste of the pounded fruit is mixed with tobacco and burnt and the smoke inhaled for respiratory ailments (Dalziel, 1937). They are also recommended to women who have newly given birth as a tonic in the Ivory Coast (Burkhill, 1985). This use is also applicable in some states of Nigeria (Southern) as well as to encourage fertility. According to Burkhill (1985) this prescription was employed one time in the government hospital Ghana, and was used for inducing or increasing menstruation flow and was used accordingly deemed to have abortifacient properties.
Prominent amongst its medicinal uses are its beneficial effects in disorders of the gut, example, in Congo the bark is steeped, in palm-wine, which is given for stomach aches at the rate of one or two glasses per day (Burkhill, 1985).
Most of the other medicinal uses however, are aimed at altering the motility of the alimentary tract, especially in cases of diarrhoea and constipation, for example in Nigeria, the powdered roots mixed with salt are used in the treatment of constipation (Burkhill, 1985). In certain parts of Africa, it is used as a purgative (Dalziel, 1937). This is in line with its use in Nigeria. However, in Gabon, it has been used in the treatment of dysentery and diarrhoea which contradicts with its use in Nigeria and Europe.
This study is being carried out to determine whether there are any pharmacological basis for the use of this plant in conditions affecting the gastro intestinal tract.
The various alkaloids found in xylopia aethiopicum and their properties are presented in Table 2. The structure of the alkaloids are presented in figure 8. The aim of representing these structures is to allow comparison between these alkaloids and other known alkaloids of medicinal value. Example anonaceine is an alkaloid found in Xylopia aethiopicum, which is structurally similar to morphine and thus is reported to have some of morphine’s properties (Dalziel, 1937; Burkhill, 1985).
Xylopia aethiopicum, has been reported to contain Xylopic acid and a number of other diterenes (Boakye, et al, 1977).
The ileum is the third part of the small intestine. The wall of the ileum is thin and single. The ileum is distinguished by the presence of the antimesenteric border of elongated whitish plagues in the mucous membrane, usually but not always visible through the muscle. These ate the aggregated lymphatic follicles (Peyer’s patches).
The smooth muscle of the ileum is in a state of tonic (intrinsic) contraction. Usually most of the digestive processes end up in the ileum with the aid of secretions from its epithelium and from accessory glands. These are the serosa, muscularis, the submucosa and the mucosa. The ileum is important in the gastro intestinal tract. Many disorders of the GIT affect the functioning of the ileum. Absorption of most food substances take place in the ileum.
The ileum has both cholinergic and adrenergic innervation. The cholinergic supply is via the vagus. The Adrenergic supply is via fibers from the celiac ganglion. Stimulation of the cholinergic nervous supply to the ileum or administration of cholinomimetic agent such as acetylcholine produce marked contraction of ileal smooth muscle, which could be antagonised by atropine. (A competitive antagonist of muscarinic cholinergic receptors). (Jacoby et al, 1963; Anderson et al, 1968; Ludwich et al, 1968; Bennett, 1972; Botton, 1972; and Bowman et al, 1980).
The contractile activity of Acetylcholine on smooth cell membrane’s to potassium (K+) and sodium (Na+) ions; (Sweiss, 1961). Calcium (Ca2+) potentiates the actions of acetylcholine on intestinal smooth muscle by increasing membrane –permeability (Hurwitz et al, 1969).