Antibacterial Effects of Urena lobata on Mice of Staphylococcus aureus Pneumonia Model in Vivo

Abstract:

Objective: To study the antibacterial activity of aqueous extract of Urena lobata (DTH) on Staphylococcus aureus in vivo. Method: One hundred and eight KM mice were randomly divided into 9 groups:the normal group, the model group, the high-, medium-, low-dose DTH groups (40, 20, 10 g·kg^-1), the cefazolin group (0.5 g·kg^-1), the DTH plus cefazolin group (DTH 20 g·kg^-1, cefazolin 0.5 g·kg^-1), the levofloxacin group (0.09 g·kg^-1), the DTH plus levofloxacin group (DTH 20 g·kg^-1, levofloxacin 0.09 g·kg^-1) of 12 each. The mouse pneumonia model of S. aureus infection was established by nasal cavity instillation. The different medicines were administrated to the mice after inoculation for 4 days. The lung tissue homogenate colony culture numbers of the mouse were monitored. The white blood cell count (WBC), the percent of neutrophile granulocyte (NEU%), absolute neutrophil count (NEU), immune globulin G (IgG) and IgM were detected. The antibacterial effects on bacterial pneumonia mice were tested. Result: The lung tissue homogenate colony culture number was (7.212±0.578), (6.210±0.570)×10⁸ CFU·g^-1, respectively, in the medium-and high-dose DTH groups, was (3.928±0.165), (2.042±0.076)×10⁸ CFU·g^-1, respectively, in the cefazolin group and DTH plus cefazolin group, which were lower than those in the model group (P <0.01). Meanwhile, the results were better in the DTH plus cefazolin group. The lung tissue homogenate colony culture number was (5.375±0.837), (4.888±0.820)×10⁸ CFU·g^-1, respectively, in the levofloxacin group and the DTH plus levofloxacin group, which were lower than those in the model group (P <0.01). Meanwhile, the results were better in the DTH plus levofloxacin group. The inflammatory exudate in the bronchial lumen and alveolar inflammatory cells infiltration decreased, alveolar structure was restored in the high-, medium-dose DTH groups and the DTH plus cefazolin, DTH plus levofloxacin groups. Moreover, the counts of WBC, NEU%,NEU and IgG, IgM decreased in the high-dose DTH group and the DTH plus cefazolin, DTH plus levofloxacin groups. Conclusion: The results suggest that DTH has a certain degree of antibacterial effects on S. aureus in vivo. There are different degrees of combination effects against S. aureus when combined with cefazolin sodium or levofloxacin.