Ish green, with serrated edges, arranged in an alternate fashion on straight branches. The young shoots and leaves are parts that are chewed for their psychoactive properties [2]. In Ethiopia, a number of local brands are available, including Aweday, Beleche, Abo mismar, Gelemso and Wondo. It is claimed that the Aweday variety cultivated* Correspondence: [email protected] Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, Addis Ababa University, P.O, Box 1176, Addis Ababa, Ethiopiain Harar highlands of Eastern Ethiopia is the most potent and expensive among the local brands, and hence chosen for export [3,4] as well as for purpose of the present study. Central nervous system stimulation such as euphoria and alertness induced by cathinone, the main active constituent derived from khat chewing, makes it popular among large segments of the society. In addition, factors like easy transportation from village to city khat markets and affordability are thought to play an important role in widening its social use in society. People also believe that khat helps to work more effectively, particularly with manual work, due to increased energy and alertness [5]. Consumption of crude khat extract or its alkaloid fraction preceding stress has been shown to produce oxidative?2014 Shewamene and Engidawork; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Chloroquine (diphosphate) supplement Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Shewamene and Engidawork BMC Complementary and Alternative Medicine 2014, 14:66 http://www.biomedcentral.com/1472-6882/14/Page 2 ofstress in rats by altering activities of serum antioxidant enzymes [6]. Nephrotoxic and hepatotoxic effects are also reported following khat administration to New Zealand white rabbits [7,8]. The generation of free radicals is seriously implicated in khat toxicity following the observation that oral exposure of rats to khat was associated with decreased serum free radicals metabolizing enzymes such as superoxide dismutase (SOD) and catalase [9]. In addition, khat treated rats displayed hepatic enlargement, abnormal findings in serum aspartate aminotransferase, and alkaline phosphatase in both sexes as well as alterations in serum albumin and creatinine in female rats [10]. In spite of the vast published data on the pharmacology and chemistry of khat, toxicological studies with laboratory animals as well as toxicity reports in humans, particularly on the renal system, are scanty. Moreover, the effect of khat-induced redox changes, at least, in the kidney, has not yet been explored. Thus, there is a need for conducting laboratory studies to generate a sufficient body of knowledge PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/25432023 in the area. This study therefore attempted to investigate whether exposure of rats to khat had a potential to cause nephrotoxicity via alteration of the renal redox system.(400 g per flask) wrapped with aluminum foil to avoid light induced decomposition. Chloroform (150 mL) and diethyl ether (450 mL) (1: 3 v/v) were added to cover the minced leaves. The resulting mixture was shaken under dark condition for 24 h using a rotary shaker (New Bru.