Antibacterial Effects of Leaf Extract of Nandina domestica and the Underlined Mechanism

Aim The study was conducted to investigate the antibacterial and antiasthmatic effects of Nandina domestica leaf extract, to find out its active components, and to assess its safety issue. Methods (1) Solid-phase agar dilution method was used for antibacterial activity test of nandina leaf extract and the change of bacterial morphology after treatment was observed under the transmission microscope; (2) guinea pig model of asthma was used to test the asthma prevention effect of nandina leaf extract; (3) alkaloids and flavones were separated from nandina leaf extract and were further analyzed with HPLC-MS; (4) mice model was used to assessment of the safety issue of nandina leaf extract. Results (1) Nandina leaf extract inhibited the growth of bacteria and destroyed bacterial membrane; (2) nandina leaf extract alleviated animal allergy and asthma; (3) the components reextracted by ethyl acetate were active, in which alkaloids inhibited Gram-positive bacteria and prevented asthma and flavones inhibited Gram-negative bacteria; (4) nandina leaf extract had no toxic effect on mice. Conclusion Nandina leaves inhibit bacterial growth and prevent asthma through alkaloids and flavones, which had integrated function against chronic bronchitis. This study provided theoretical basement for producing new Chinese medicine against chronic bronchitis.