Epiberberine, a natural protoberberine alkaloid, inhibits urease of Helicobacter pylori and jack bean: Susceptibility and mechanism.
In our previous study, Rhizoma Coptidis extract was found to exert more potent inhibitory effect than its major component berberine towards urease from Helicobacter pylori (HPU) and jack bean (JBU). In continuation of our work, the present study was designed to further comparatively investigate the urease inhibitory activities of five major protoberberine alkaloids in Rhizoma Coptidis, namely berberine, palmatine, coptisine, epiberberine, jateorhizine to identify the bioactive constituent, and illuminate the potential mechanism of action. Results indicated that the five protoberberine alkaloids acted as concentration-dependent inactivators of urease with IC50values ranging between 3.0 and 5087μM for HPU and 2.3->10,000μM for JBU, respectively. Notably, epiberberine (EB) was found to be the most potent inhibitor against both ureases with IC50values of 3.0±0.01μM for HPU and 2.3±0.01μM for JBU, which was more effective than the standard urease inhibitor, acetohydroxamic acid (83±0.01μM for HPU and 22±0.01μM for JBU, respectively). Further kinetic analysis revealed that the type of EB inhibition against HPU was slow-binding and uncompetitive, with Kiof 10.6±0.01μM, while slow-binding and competitive against JBU with Kiof 4.6±0.01μM. Addition of thiol reagents, such as l-cysteine, glutathione and dithiothreitol, significantly abolished the inhibition, while Ni2+competitive inhibitors, boric acid and sodium fluoride, synergetically inhibited urease with EB, indicating the obligatory role of the active site sulfhydryl group for the inhibition. In addition, binding of EB with the urease proved to be reversible, as about 65% and 90% enzymatic activity of HPU and JBU, respectively, could be restored by dithiothreitol application. These findings highlighted the potential role of Rhizoma Coptidis protoberberine alkaloids, especially EB, as a lead urease inhibitor in the treatment of diseases associated with ureolytic bacteria. Thus, EB had good potential for further development into a promising therapeutic approach for the treatment of urease-related diseases.
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Guangdong Provincial Key Laboratory of New Chinese Medicinal Development and Research, Guangzhou 510006, People's Republic of China.
Lihua
L
Tan
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Guangdong Provincial Key Laboratory of New Chinese Medicinal Development and Research, Guangzhou 510006, People's Republic of China.
Cailan
C
Li
The First Affiliated Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510405, People's Republic of China.
Hanbin
H
Chen
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Guangdong Provincial Key Laboratory of New Chinese Medicinal Development and Research, Guangzhou 510006, People's Republic of China.
Zhizhun
Z
Mo
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Guangdong Provincial Key Laboratory of New Chinese Medicinal Development and Research, Guangzhou 510006, People's Republic of China.
Jiangtao
J
Zhou
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Guangdong Provincial Key Laboratory of New Chinese Medicinal Development and Research, Guangzhou 510006, People's Republic of China.
Yuhong
Y
Liu
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China.
Zhilin
Z
Ma
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China.
Yuyao
Y
Xu
Guangdong Provincial Key Laboratory of Clinical Research on Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou 510120, People's Republic of China.
Xiaobo
X
Yang
Guangdong Provincial Key Laboratory of Clinical Research on Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou 510120, People's Republic of China. Electronic address: xiejianhui123@aliyun.com.
Jianhui
J
Xie
School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China; Guangdong Provincial Key Laboratory of New Chinese Medicinal Development and Research, Guangzhou 510006, People's Republic of China; Dongguan Mathematical Engineering Academy of Chinese Medicine, Guangzhou University of Chinese Medicine, Dongguan 523808, People's Republic of China. Electronic address: suziren@126.com.
Ziren
Z
Su
D001599:Berberine / Q000031:analogs & derivatives* / Q000737:chemistry; D032449:Canavalia / Q000201:enzymology; D000089042:Coptis chinensis; D003545:Cysteine / Q000737:chemistry; D004229:Dithiothreitol / Q000737:chemistry; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry; D016480:Helicobacter pylori / Q000201:enzymology; D006877:Hydroxamic Acids / Q000737:chemistry; D007700:Kinetics; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D010940:Plant Proteins / Q000037:antagonists & inhibitors*; D014510:Urease / Q000037:antagonists & inhibitors* / Q000737:chemistry
D004365:Drugs, Chinese Herbal; D006877:Hydroxamic Acids; D010940:Plant Proteins; D001599:Berberine; C006358:acetohydroxamic acid; C061432:epiberberine; C107393:Coptidis rhizoma extract; D014510:Urease; D005978:Glutathione; D003545:Cysteine; D004229:Dithiothreitol
Acetohydroxamic acid (PubChem CID: 1990); Berberine (PubChem CID: 2353); Boric acid (PubChem CID: 7628); Coptisine (PubChem CID: 72322); Dithiothreitol (PubChem CID: 446094); Epiberberine; Epiberberine (PubChem CID: 160876); Glutathione (PubChem CID: 124886); Helicobacter pylori urease; Inhibitor; Jack bean urease; Jateorhizine (PubChem CID: 72323); Palmatine (PubChem CID: 73442); Protoberberine alkaloids; Sodium fluoride (PubChem CID: 5235); Sulfhydryl group; l-cysteine (PubChem CID: 5862)