Jundishapur J Chronic Dis Care. 2019 October; 8(4):e96058. Published online 2019 October 23. doi: 10.5812/jjcdc.96058. Review Article A Review on Antibacterial Effects of Iranian Herbal Medicine on Methicillin-Resistant Staphylococcus aureus Masoumeh Baradaran 1, * and Amir Jalali 2 1 Toxicology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2 Department of Pharmacology and Toxicology, Toxicology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran * Corresponding author: Toxicology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Tel: +98-6133738383, Email: mb.baradaran@gmail.com Received 2019 July 06; Revised 2019 September 28; Accepted 2019 October 04. Abstract Context: Staphylococcus aureus (S. aureus) is an opportunistic pathogen that is able to cause different types of life-threatening infec- tions from acute bacteremia to often chronic osteomyelitis, endocarditis, infections of indwelling devices and wound infections. These chronic infections are highly recalcitrant to antibiotic treatment. Owing to the increasing incidence of S. aureus infections and resistance with long-term treatment with available antibiotics, S. aureus is notorious. Research for new drugs, especially from natural sources is ongoing. Plants were commonly used in the treatment of diseases by a primary human from ancient times. Ex- hibiting minimum side effects, ease of use, availability, and commonly cost-effective are the advantages of plants. So in the last few decades, research on herbal medicine is getting popularized. Evidence Acquisition: In this systematic review, we aimed to review antimicrobial potential of essential oil and different extracts (methanolic, ethanolic, ethyl acetate, ether or aqueous extracts) from 31 genera of medical plants, including 83 species against S. au- reus and its most frequent resistant strain, methicillin-resistant S. aureus (MRSA) for introducing them as potent therapeutic agents. To find intended articles, we searched in several databases using a list of suitable keywords. Results: The essential oil of T. caucasicus has the best inhibitory effect on S. aureus. However, extract of 8 plant species has also the acceptable inhibitory effect. Surprisingly, essential oil of some plants showed better anti-staphylococcal effect than standard antibiotics. Moreover, twelve plant species have effective inhibitory effect against MRSA. Conclusions: Some of the evaluated Iranian plants such as T. parthenium, T. vulgaris, T. eriocalyx, T. persicus, A. millefollum, P. harmala, H. scabrum, and S. urmiensis with acceptable MIC or inhibition zone have the potency of antimicrobial activity, especially against S. aureus and MRSA. According to the comparison, essential oil of Thymus caucasicus with the MIC value of 0.31 μg/mL for S. aureus and 2.5 μg/mL for MRSA has the best inhibitory effect. So the mentioned natural extract, especially essential oil of T. caucasicus can be a candidate for drug design with the goal of the treatment of S. aureus infections. Keywords: Herbal Medicine, Antimicrobial Susceptibility, Staphylococcus aureus, Chronic Infections 1. Context Infectious diseases are the second leading cause of death worldwide (1). Staphylococcus aureus (S. aureus) is one of the important and problematical infectious pathogens (2). It is an opportunistic pathogen and is the primary cause of lower respiratory tract and surgical site infections, and the second leading cause of nosocomial bacteremia, pneumonia, and cardiovascular infections (3). Moreover, S. aureus is often found among chronic and recurrent bone infections, and is often the cause of chronic osteomyelitis, endocarditis, infections of indwelling devices and postsur- gical wound infections such as chronic biofilm-associated infections in prosthetic devices (4). In recent years, the emergence of antibiotic-resistant forms of pathogenic S. aureus is a worldwide problem in clinical medicine (5). Methicillin-resistant S. aureus (MRSA) is the most common antibiotic-resistant of all antibiotic-resistant threats. The MRSA was first identified five decades ago (6). Hereafter, MRSA infections have spread in Europe, the Americas, and the Asia-Pacific region (7). Hence the search for newer, safer and more potent antimicrobials with less susceptibility to the resistance is a pressing need (8). Evidence currently shows that improved quality of life is considerably impor- tant in the treatment of chronic diseases (9). The negative effects of chronic infection induced by MRSA on the qual- ity of life increase the need to search for newer, safer, and more potent antimicrobial agents with less susceptibility to resistance is a pressing need (8). Plants were commonly used in the treatment of dis- Copyright © 2019, Jundishapur Journal of Chronic Disease Care. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.