title: Synergy between baicalein and penicillins against penicillinase-producing Staphylococcus aureus.
abstract: The combination of baicalein (the active constituent of Scutellaria baicalensis) with penicillin G/amoxicillin showed potent synergy against 20 clinical penicillinase-producing Staphylococcus aureus strains including 10 isolates that were additionally methicillin-resistant (MRSA). The fractional inhibitory concentration (FIC) indices of penicillins+baiclein ranged from 0.14 to 0.38. Baicalein protected penicillins (penicillin G and amoxicillin) from penicillinase and increased the susceptibility of penicillinase-supplemented S. aureus ATCC 29213 in a dose-dependent manner. The inhibition of penicillinase activity by baicalein should be responsible for the synergism and protective effect. These findings offer us good evidence that the penicillins combined with baicalein showed potent synergistic activity against penicillinase-producing S. aureus and penicillinase-producing MRSA in vitro and might provide promising implications for clinical treatment of these bacterial infections.
authors.affiliation: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Minyi
authors.initials: M
authors.lastname: Qian
authors.affiliation: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Shusheng
authors.initials: S
authors.lastname: Tang
authors.affiliation: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Congming
authors.initials: C
authors.lastname: Wu
authors.affiliation: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: He
authors.affiliation: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Chen
authors.affiliation: National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China. Electronic address: xiaoxl58@126.com.
authors.forename: Xilong
authors.initials: X
authors.lastname: Xiao
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D044950:Flavanones / Q000494:pharmacology*; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D010405:Penicillinase / Q000378:metabolism; D010406:Penicillins / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000201:enzymology
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D044950:Flavanones; D010406:Penicillins; C006680:baicalein; D010405:Penicillinase
keywords: Baicalein; MRSA; Penicillinase; Penicillinase-producing Staphylococcus aureus; Penicillins; Synergism