title: Synergistic antibacterial effect of curcumin against methicillin-resistant Staphylococcus aureus.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) are spread among infected patients, with infection rates increasing at an alarming rate. Furthermore, increased resistance to antibiotics has resulted in serious challenges in the treatment of infectious diseases worldwide. Under the selection pressure of exposure to antibiotics, microorganisms evolve to survive against the new conditions imposed by therapy. Therefore, there exists a need to develop alternative natural or combination drug therapies. Curcumin (CCM), a natural polyphenolic flavonoid isolated from the rhizome of a plant, Curcuma longa Linné., has been found to possess many beneficial biological activities. The aim of this study was to investigate the synergistic effect of curcumin and antibiotics as well as to determine the antibacterial activity of CCM against specific MRSA strains. The antibacterial activity of CCM was assessed by the broth microdilution method (by calculating the minimal inhibitory concentration [MIC]), checkerboard dilution test, and time-kill assay. Antimicrobial activity of CCM was observed against all tested strains. The MICs of CCM against 10 strains of S. aureus ranged from 125 to 250 μg/ml. In the checkerboard test, CCM markedly reduced the MICs of the antibiotics oxacillin (OXI), ampicillin (AMP), ciprofloxacin (CIP), and norfloxacin (NOR) used against MRSA. The time-kill curves showed that a combined CCM and OXI treatment reduced the bacterial counts below the lowest detectable limit after 24h. This study suggested that CCM reduced the MICs of several antibiotics tested, notably of OXI, AMP, CIP, and NOR, and that CCM in combination with antibiotics could lead to the development of new combination of antibiotics against MRSA infection.
authors.affiliation: College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Institute of Biotechnology, Wonkwang University, Jeonbuk 570-749, Republic of Korea.
authors.forename: Su-Hyun
authors.initials: SH
authors.lastname: Mun
authors.forename: Dae-Ki
authors.initials: DK
authors.lastname: Joung
authors.forename: Yong-Sik
authors.initials: YS
authors.lastname: Kim
authors.forename: Ok-Hwa
authors.initials: OH
authors.lastname: Kang
authors.forename: Sung-Bae
authors.initials: SB
authors.lastname: Kim
authors.forename: Yun-Soo
authors.initials: YS
authors.lastname: Seo
authors.forename: Youn-Chul
authors.initials: YC
authors.lastname: Kim
authors.forename: Dong-Sung
authors.initials: DS
authors.lastname: Lee
authors.forename: Dong-Won
authors.initials: DW
authors.lastname: Shin
authors.forename: Kee-Tae
authors.initials: KT
authors.lastname: Kweon
authors.forename: Dong-Yeul
authors.initials: DY
authors.lastname: Kwon
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology; D030024:Curcuma / Q000737:chemistry*; D003474:Curcumin / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009643:Norfloxacin / Q000494:pharmacology; D010068:Oxacillin / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D027343:Rhizome / Q000737:chemistry; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D002939:Ciprofloxacin; D000667:Ampicillin; D003474:Curcumin; D009643:Norfloxacin; D010068:Oxacillin