Histological Studies Of The Effects Of Oral Administration Of Aspilia Africana (Asteraceae) Leaf Extract On The Ovaries Of Female Wistar Rats

摘要

Histological studies of the effects of oral administration of extract of Aspilia africana, used in ethno medical practice in Africa for the management of various ailments, on the ovarian tissues of matured female Wistar rats were carefully studied. The rats (n=24), average weight 0f 182g were randomly assigned into two treatments (n=16) and control (n=8) groups. The rats in the treatment groups received 0.5g/kg and 1g/kg of aqueous extract of Aspilia africana orally through orogastric tube for fourteen days, while the control rats received equal volume of distilled water without the extract of Aspilia added. The rats were fed with grower's mash purchased from Edo feeds and Flour Mill Ltd, Ewu, Edo state and were given water liberally. The rats were sacrificed on day fifteen of the experiment. The ovary was carefully dissected out and quickly fixed in 10% formal saline for routine histological study after H&E method.The histological findings after H&E methods indicated that the treated sections of the ovary showed some cellular hypertrophy of the Theca folliculi, complete distortion/destruction of the basement membrane. Degenerative and atrophic changes were observed in the oocyte and zona granulosa; these were more pronounced in those that received 1g/kg of aspilia africana extract. There were marked vacuolations appearing in the stroma cells when compared to the control sections. These findings indicate that Aspilia africana consumption may probably have adverse effects on the ovaries by its deleterious effects on the oocytes and stroma cells of ovary of adult Wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out. Introduction Plant materials as sources of medical compounds continue to play a dominant role in the maintenance of human health since antiquity. Over 50% of all modern chemical drugs are of natural plant product origin, and is essential in drug development programs of the pharmaceutical industry1. Like any therapeutic agent, when overdosed or incorrectly used they also have the potential to induce adverse effects. The historic role of medicinal herbs in the treatment and prevention of disease, and their role as catalysts in the development of pharmacology do not, however, assure their safety for uncontrolled use by an uninformed public2. There has been minimal research to address possible adverse reproductive, immunologic, or neurological effects or even systemic toxicity and/or carcinogenicity that might be associated with high doses or prolonged use of these products3. This concern was frequently expressed at the International Workshop to Evaluate Research Needs on the Use and Safety of Medicinal herbs could not be assumed safe because they are “natural”4. In Benin City, Nigeria, many plants are used in herbal medicine to cure diseases and heal injuries. Such medicinal plants include Aspilia Africana (Asteraceae), a perennial herb varying in height from 60cm to about 1.5m depending on rainfall. It is a common weed of field crops in West Africa and sometimes found in fallow land, especially the forest zones5. It is ligneous at the base, its fruit quadrangular akenes and leaves opposite and hairy. The plant is a weed grazed by cattle and sheep and is mostly used in the western state of Nigeria as food for rabbits and hares6. Aspilia Africana is widely used in ethno medical practice in Africa for its ability to stop bleeding, even from a severed artery, as well as promote rapid healing of wounds and sores and for the management of problems related to cardiovascular diseases7. It has also been established that Aspillia Africana has an anticoagulant activities8. Infusion of the leaves is taken by children and can also be mixed with clay as a medicine for stomach trouble9. It has been reported that the plant is effective against malaria infection10`. It has been classified among substances with low toxicity, with an LD50 averaging 6.6g/Kg body weight11. The methano