Abstract

Persea americana (Avocado) is a fruit consumed globally, and in Nigeria due to its many nutritive and dietary benefits. While the nutritive properties of the fruits have been easily observed due to popular consumption, the potential nutritive properties of other parts of the plant, particular the seed– commonly discarded after consumption– is not commonly acknowledged. Ethanol (alcohol) is an organic compound which is consumed recreationally in Nigeria, with detrimental effects to various organs observed with prolonged overconsumption. An interest in the ameliorative effects of P. americana (Avocado) seed extract on the histology of ethanol-induced lung damage in albino rats propelled this study. The sample to be investigated was identified and authenticated, while alcoholic extraction of the plant was carried out. Twenty-eight (28) Albino rats were grouped and labelled (I to IV), housed in plastic cages with wire gauge for adequate ventilation, and provided with pelleted feed and water ad libitum. Room temperature and relative humidity were maintained, and the animals were acclimatized for a period of two weeks prior to the commencement of the experiment. All rats used for this study were treated by oral intubation for 20 days, with Group I administered distilled water only (positive control). Group II (negative control) was administered 1.0 ml/kg body weight of 80%ethanol as a single daily dose for the full duration of the study.  Group III initially received 1.0 ml/kg b.w.t of 80% ethanol once daily for 10 days followed by 250 mg/kg b.w.t of P. americana crude extract orally as a single daily dose for another 10 days. Group IV was administered 1.0 ml/kg b.w.t of 80% ethanol once daily for 10 days followed by 500 mg/kg b.w.t of P. americana crude extract as a single daily dose for the remaining 10 days. Animals from each group were anaesthetized with chloroform and sacrificed by fenestration 24 hours after the last day of administration. The lungs were excised from all groups with a sterile surgical blade, washed in saline, fixed in 10% neutral buffered formalin and cut into 3-5mm thick pieces. Cut tissues were processed, and general tissue structure of the lung section was demonstrated using Hematoxylin and Eosin staining method. Histopathology findings and photomicrographs obtained from positive and negative control rats were compared with those of the treated groups and revealed normal and regular lung architecture in Group I (positive control group). Distortion in lung architecture was observed in Group II (negative control), with mildly affected lung architecture in Group III. Group IV showed normal lung architecture consistent with the positive control (Group I). This study concludes that P. americana is relatively fit for consumption without posing pneumotoxic side effects. It also showed potential to alleviate alcohol induced lung damage. It is recommended that the mechanism of action of ameliorative potential of P. americana on the lungs should be further investigated.