title: Transformation of cinnamic acid from trans- to cis-form raises a notable bactericidal and synergistic activity against multiple-drug resistant Mycobacterium tuberculosis.
abstract: Tuberculosis (TB) is a contagious disease caused by Mycobacterium tuberculosis. The long course of treatments on TB with a combination of antibiotics leads unfavorable side effects and poor patient compliance which contributes to sustaining multiple-drug resistant tuberculosis (MDR-TB). Therefore, the development of a new effective drug or synergist to reduce the prevalence of MDR-TB is urgent to date. Cinnamic acid (CA) is a natural occurring phenolic compound with anti-microbial activity. Both trans- and cis-isoforms of CA exist in planta, and cis-cinnamic acid (c-CA) can be transformed from trans-cinnamic acid (t-CA) under sunlight. Due to the unavailability of c-CA, the literature regarding the biological functions of c-CA is still limited. We had previously developed a practicable method for the transformation of c-CA from t-CA and the isolation of c-CA. Using the techniques, sufficient c-CA was obtained to evaluate its antituberculosis activity against a MDR M. tuberculosis strain. Moreover, the synergistic effects of c-CA and t-CA with two first-line anti-TB antibiotics, isoniazid (INH) and rifampicin (RIF), were also determined. Although both of c-CA and t-CA decreased the viability of MDR-TB bacilli in a dose-dependent manner, the antituberculosis activity of c-CA was approximately 120-fold of t-CA. Furthermore, the c-CA exhibited higher synergistic effect with INH or RIF against tuberculosis than t-CA. The micrographs of scanning electron microscope (SEM) display that c-CA caused an injury on the out-layer of MDR-TB bacilli. The c-CA might be a potential anti-mycobacterial or synergistic agent that can be developed to against tuberculosis.
authors.affiliation: Graduate Institute of Applied Science of Living, Tainan University of Technology, 529 Zhongzheng Rd., Yongkang District, Tainan City 71002, Taiwan.
authors.forename: Yen-Ling
authors.initials: YL
authors.lastname: Chen
authors.forename: Shao-Tsung
authors.initials: ST
authors.lastname: Huang
authors.forename: Fang-Ming
authors.initials: FM
authors.lastname: Sun
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Chiang
authors.forename: Chia-Jung
authors.initials: CJ
authors.lastname: Chiang
authors.forename: Chiung-Man
authors.initials: CM
authors.lastname: Tsai
authors.forename: Chia-Jui
authors.initials: CJ
authors.lastname: Weng
mesh_terms: D000904:Antibiotics, Antitubercular / Q000494:pharmacology* / Q000627:therapeutic use; D002934:Cinnamates / Q000737:chemistry / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D004357:Drug Synergism; D006801:Humans; D007536:Isomerism; D007538:Isoniazid / Q000494:pharmacology / Q000627:therapeutic use; D008855:Microscopy, Electron, Scanning; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000648:ultrastructure; D012293:Rifampin / Q000494:pharmacology / Q000627:therapeutic use; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy*
chemical_list: D000904:Antibiotics, Antitubercular; D002934:Cinnamates; C029010:cinnamic acid; D007538:Isoniazid; D012293:Rifampin