BIOLOGIA (PAKISTAN) 2014, 60 (1), 135-138 PKISSN 0006 – 3096 (Print) ISSN 2313 – 206X (On-Line) *Corresponding author: s_nadeem77@yahoo.com Histological comparison of natural lung injury in Rattus norvegicus induced by a natural herb (Nerium oleander) and a known carcinogen (thioacetamide) MUDDASIR HASSAN ABBASI 1 , SANA FATIMA 2 AND * NADEEM SHEIKH 3 1 Department of Zoology, Govt. College of Science, Wahdat Road, Lahore 2 University of Health Sciences, Lahore. 3 Cell and Molecular Biology Lab, Department of Zoology, University of the Punjab, Lahore. ABSTRACT Plant extracts have extensively been studied to look for the treatment of various diseases but their poisoning effects have also been reported. The current study was undertaken with the objective of comparing acute toxic effect of Thioacetamide (TAA), a proven toxicant and Nerium oleander (N. oleander), a herb reported to have multiple therapeutic properties including anti-inflammatory, antifungal, antibacterial and antioxidative effects using histological parameters. Animals in group A were treated with 10 ml/kg of aqueous decoction of leaves of the plant while 300mg/kg of TAA was administered in group B and control (Con.) did not receive any treatment (n=3). Histological alterations in the lungs were then studied after 6 hours of respective treatment. There was an onset of more or less similar destruction of the tissue in both the experimental groups. Disruption of bronchus mucosal folds and alveolar cells along with significant nodule like accumulation of macrophages and mononuclear cells around arteriole were noticed. These results indicated that use of ethno-medicines, like N. oleander caused similar histological alterations in lungs as that of known carcinogen TAA. Thus, application of N. oleander may pose a serious risk for health. Keywords. Lung, Nerium oleander, Thioacetamide. ____________________________________________________________________________________ INTRODUCTION Plants are the largest source of herbal medicines worldwide and these have the potential to be both therapeutic and harmful but still masses of population rely on such remedies. Nerium oleander, (N. oleander), (Apocynaceae) an ornamental shrub commonly known as “Kaner”, has been used as a traditional medicine and is reputed to have wide spectrum of bioactivities including pharmaceutical products (Anvirzel), molluscicide, rodenticide and insecticides (Wang et al., 2000; Adome et al., 2004; Turan et al., 2006; Derwich et al., 2010). But poisoning action of this plant has also been reported with significant time-dependent cytotoxic effects in cattle, goat, man and other experimental animal models (Langford & Boor, 1996; Aslani & Rezakhani, 2000; Hughes et al., 2002; Smith et al., 2003; Barbosa et al., 2008; Abbasi et al., 2013b). Animals exposed to the plant are often found suddenly dead owing to cardiac dysfunction. Oral doses of N. oleander proved fatal to animals within 1 to 24 hours with clinical toxicosis (Aslani et al., 2007). Thioacetamide (TAA) a proven carcinogen has been extensively reported to produce toxic effects in animals and is suitable for studying and comparing the histological alterations (Abbasi et al., 2013a). The aim of this study was to compare acute toxic effect of TAA and N. oleander produced histological variations in lungs of albino rats and to find out whether the injury caused by TAA resembles with N. oleander induced injury. MATERIALS AND METHODS Animals Male wistar rats of about 200g body weights, were kept in a well ventilated hygienic animal house under standard conditions with 12-h light/dark cycles and access to fresh water and food pellets ad libitum. All the animals were acclimatized for a period of 2 weeks before the experiment. Plant Material Fresh leaves of N. oleander were collected from Govt. College of Science (GCS), Lahore, Pakistan. The plant material was identified by comparing with the reference collection available in the Herbarium of GCS, Lahore, Pakistan and had been preserved in Department of Botany, GCS for further reference. Extraction protocol Air-dried leaves were processed according to the method of Rashan et al., 2011, with modifications. Briefly, the leaves decoction was