Effects of subcutaneous injection with different doses of ginseng on the rat model of chronic Pseudomonas aeruginosa pneumonia

OBJECTIVE: To observe the effect of ginseng extracts on a rat model of chronic Pseudomonas aeruginosa (PA) pneumonia.

METHODS: Subcutaneous injection with four different doses of ginseng aqueous extracts to the model rats for two weeks.

RESULTS: Milder macroscopic lung pathology and lower incidence of lung abscesses were found in all the four groups received different doses of ginseng treatment compared to the control group (P < 0.05). Histopathology of the lungs was negatively correlated with the ginseng doses (r = -0.95, P < 0.01). The mast cell number in the lung foci in group I, II and IV was significantly lower than that in the control group (P < 0.05). Bacterial clearance in group II and group III was enhanced significantly (P < 0.05) compared with that in the control group. The specific antibody responses were down-regulated in group II, III and IV (P < 0.01), and IgM level in group I was lower compared to the control group (P < 0.01). Serum IgM level was positively correlated with the ginseng doses (r = 0.93, P < 0.05). IgG2a titer in group I was higher than that in the control group (P < 0.05). Serum IgG2a level was positively correlated with the ginseng doses (r = 0.90, P < 0.02). Two weeks after PA lung infection, the serum level of IgG against PA, aeruginosa alginate in group I, II, and III was higher than that in the control and group IV (P < 0.05), and the anti-alginate IgA level in group I, III and IV was lower than that in the control (P < 0.05).

CONCLUSIONS: The ginseng dose of 2.5 mg/kg was the best dosage in the present study, and it showed an effect of stimulating T helper type I response.