Protective efficacy of Emblica officinalis against Klebsiella pneumoniae induced pneumonia in mice.

BACKGROUND & OBJECTIVES Emblica officinalis (amla), which is a good source of vitamin C, has been shown to be beneficial due to its immune system enhancing property coupled with its tonifying and antiageing effect. The present study was conducted to evaluate the effect of E. officinalis feeding on the susceptibility of experimental mice to respiratory tract infection induced by Klebsiella pneumoniae. METHODS The effect of short- (15 days) and long (30 days)-term feeding of amla in mice on the course of K. pneumoniae ATCC43816 infection in lungs was studied, in terms of bacterial colonization, macrophage activity, malondialdehyde (MDA) and nitrite production in broncheoalveolar lavage fluid (BALF). Tumour necrosis factor (TNF)-alpha level in serum was also assessed. RESULTS Though there was a decrease in bacterial colonization after short-term feeding, it was not significant. On the contrary, the decrease in bacterial load was significant (P < 0.05) on long-term feeding. The operative mechanisms in terms of lipid peroxidation, phagocytosis and nitrite production were studied by estimating their levels in broncheoalveolar lavage fluid (BALF). Maximum decrease in malondialdehyde (MDA) levels and increase in phagocytic activity and nitrite levels on long-term feeding was seen. INTERPRETATION & CONCLUSION These results suggest that dietary supplementation with amla protects against bacterial colonization of lungs on long-term feeding in experimental model. Further studies need to be conducted to understand the actual mechanism.