Journal of Ethnopharmacology 121 (2009) 286–291 Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jethpharm Bactericidal activity of medicinal plants, employed for the treatment of gastrointestinal ailments, against Helicobacter pylori Syed Faisal Haider Zaidi a,b , Kazuki Yamada b , Makoto Kadowaki a , Khan Usmanghani c , Toshiro Sugiyama b,∗ a Division of Gastrointestinal Pathophysiology, Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Japan b Department of Gastroenterology and Hematology, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan c Department of Basic Clinical Sciences, Faculty of Eastern Medicine, Hamdard University, Karachi 74600, Pakistan article info Article history: Received 15 June 2008 Received in revised form 24 September 2008 Accepted 1 November 2008 Available online 8 November 2008 Keywords: Anti-Helicobacter pylori activity Pakistani herbs Mallotus phillipinensis Minimum bactericidal concentration abstract Aim of the study: Helicobacter pylori infection plays a crucial role in the pathogenesis of peptic ulcer, and gastric cancer. The current PPI-based triple regimens for the eradication of Helicobacter pylori faces uprising resistance problem demanding for the search of novel candidates. Medicinal plants have always been a source of lead compounds for drug discovery. In the present study, we evaluated the anti-Helicobacter pylori activity of 50 commonly used Unani (traditional) medicine plants from Pakistan that are extensively utilized for the cure of gastrointestinal disorders to explore the natural source for pilot compounds against Helicobacter pylori. Materials and methods: Total seven clinical isolates and one standard strain were employed to examine the bactericidal effects of medicinal plants. Helicobacter pylori was isolated from the antral biopsy speci- mens and confirmed through the standard microbiology procedures. Minimum bactericidal concentration (MBC) of the active plants was determined at the concentration range from 7.8 to 500 g/ml. Results: Among the herbs evaluated, more than 50% inhibited the growth of eight strains at the concen- tration of 500 g/ml. The 70% aqueous-ethanol extracts of Curcuma amada Roxb., Mallotus phillipinesis (Lam) Muell., Myrisctica fragrans Houtt., and Psoralea corylifolia L. demonstrated strong anti-Helicobacter pylori activity with MBC value ranged from 15.6 to 62.5 g/ml. The most potent bactericidal activity was exhibited by Mallotus phillipinesis (Lam) Muell. which completely killed the bacteria at the concentration of 15.6–31.2 g/ml. Conclusion: The results revealed significant anti-Helicobacter pylori activity of medicinal plants which could be the potential source of new bactericidal agents. © 2008 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Helicobacter pylori, a Gram-negative bacterium, is one of the most widespread infections in human worldwide that persistently infects up to 50% of the world’s population (Suerbaum and Michetti, 2002). Infections have been reported to be higher in the develop- ing than in the developed countries with up to almost 100% of the population being infected in some developing nations (Marshal and Gilman, 1999). The infection is associated with atrophic gas- tritis, duodenal ulcer or gastric ulcer, and gastric adenocarcinoma at a later stage (Covacci et al., 1999). Eradication of the organ- ism has been shown to result in ulcer healing, prevention of peptic ulcer recurrence and may also reduce the prevalence of ∗ Corresponding author. Tel.: +81 76 434 7300; fax: +81 76 434 5027. E-mail address: tsugi@med.u-toyama.ac.jp (T. Sugiyama). gastric cancer in high-risk populations (Sepulveda and Coelho, 2002). Several short course drug regimens have been prescribed for the eradication of Helicobacter pylori with different combinations of therapeutic agents such as antibiotics, bismuth subsalicy- late, proton pump inhibitors and H 2 -blockers (Hentschel et al., 1993). However, emerging resistance to antibiotics, especially clar- ithromycin and metronidazole limits their use in the treatment of infections in developed and more in developing countries (Sullivan et al., 1990; Lind et al., 1999; Sherif et al., 2004). Furthermore, undesirable side effects of the drugs and the significant cost of com- bination therapy, require the exclusive need to search alternative approaches of eradicating or preventing infections (O’Gara et al., 2000). Phytomedicine has proved to be an untapped treasure for the discovery of model compounds to cure different diseases including gastrointestinal (GI) disorders (Thompson and Ernst, 2002). Hence, several studies have been focused to evaluate the anti-Helicobacter 0378-8741/$ – see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2008.11.001