IMMUNOLOGY, HEALTH, AND DISEASE Peganum harmala Can Minimize Escherichia coli Infection in Poultry, but Long-Term Feeding May Induce Side Effects N. Arshad,*† C. Neubauer,* S. Hasnain,† and M. Hess* 1 *Department for Farm Animals and Herd Management, Clinic for Avian, Reptile and Fish Medicine, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria; and †Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan ABSTRACT Peganum harmala seed extracts have been frequently reported to possess antibacterial potential through in vitro studies, but in vivo studies have acquired less attention. The present study was therefore designed to investigate its efficacy on the course of colibacillosis and effects of long-term feeding on selected parameters of general health in chickens. Two experiments were con- ducted in this regard. Experiment 1 (a pilot study) was performed to determine the dose of a field strain of Esche- richia coli (O1:K1) required to induce clinical symptoms in 4- and 15-d-old specific-pathogen-free chickens. A suc- cessful induction of colibacillosis, in terms of clinical signs, mortality, and pathological lesions in addition to reisolation of the pathogen was observed by inoculating 4- and 15-d-old chicks with 4.3 log 10 and 6.4 log 10 cfu of E. coli, respectively, by intraperitoneal injection. Using these doses experiment 2 (main study) consisting of a single experiment with 3 parts was performed. Parts A and B generated the information regarding efficacy of Key words: Peganum harmala, antimicrobial, in vivo, colibacillosis, poultry 2008 Poultry Science 87:240–249 doi:10.3382/ps.2007-00341 INTRODUCTION Bacterial infections in poultry remain of great impor- tance world-wide in terms of economic effects and public health. Antibiotic therapy and prophylaxis are widely used, keeping in mind the associated problems of devel- oping resistant pathogens (Barrow, 1997; Saenz et al., 2001; Altekruse et al., 2002). As a consequence of existing reports about multidrug resistance, the fear of the gen- eral loss of effective antimicrobials is increasing (FDA, 2001). This problem has led to an intensified research for alternative treatments. Plant products are considered as one of the active research areas in this context. Medici- nal plants are being explored with the intention of find- ©2008 Poultry Science Association Inc. Received August 17, 2007. Accepted October 22, 2007. 1 Corresponding author: michael.hess@vu-wien.ac.at 240 the extract against infection in 4- and 15-d-old chickens applying different treatment schemes, whereas the effects of continuous feeding of the extract were assessed in part C. Whereas no protective effect of the extract could be recorded in young chickens, significant differences (P < 0.05) with regard to BW, clinical score, gross lesion score, and total granulocyte counts were observed in 15-d-old birds. Bacterial recovery per gram of tissue and reisolation frequency were lower in treated birds. The continuous feeding of the extract for 6 wk resulted in an augmentation in relative liver weight and depletion in alkaline phospha- tase, protein, albumin, and globulin. It can be concluded that the crude extract of Peganum harmala possesses lim- ited antimicrobial activity against E. coli in vivo and long- term continuous feeding may induce undesired effects. Furthermore, the study underlines the value of in vivo experiments and the diverse picture that herbal products, in this case Peganum harmala, may deliver by testing them against specific pathogens. ing new antimicrobial agents, especially against drug- resistant bacteria. Some of these plants have been re- ported to possess broad-spectrum antimicrobial activity against resistant bacterial strains (Fukai et al., 2004; Dick- son et al., 2006; Kuz ´ma et al., 2007). In vitro results of many plant extracts are being reported with great frequency from different laboratories (Cowan, 1999; Rı ´os and Recio, 2005). However, fewer data are available re- garding in vivo testing of these extracts (Lamchouri et al., 2002; Guo et al., 2004; Stipkovits et al., 2004; Lamien et al., 2005). Only few studies are available on the exploi- tation of plant extracts as antimicrobial agents using in vivo infection models (Stipkovits et al., 2004; Bandyo- padhyay et al., 2005; Prakash, 2006). Peganum harmala, although considered as a noxious weed, has some beneficial effects. The smoke of its seeds is traditionally used as a disinfectant (Shahverdi et al., 2005). Its seed extracts are known to contain β-carbolin alkaloids, anthroquinons, and a small quantity of flavo- by guest on December 31, 2014 http://ps.oxfordjournals.org/ Downloaded from