Induction of resistance to respiratory tract infection with Klebsiella pneumoniae in mice fed on a diet supplemented with tulsi (Ocimum sanctum) and clove (Syzgium aromaticum) oils.

BACKGROUND AND PURPOSE The impact of diet and specific food groups on respiratory tract infections has been widely recognized in recent years. This study was conducted to study the effect of tulsi (Ocimum sanctum) oil and clove (Syzgium aromaticum) oil on the susceptibility of experimental mice to respiratory tract infection. METHODS The effect of 2 different regimens of short-term (15 days) and long-term (30 days) feeding with tulsi oil and clove oil on the course of Klebsiella pneumoniae American Type Culture Collection 43816 infection in the lungs of mice was analyzed. The operative mechanisms of lipid peroxidation/nitrite production were studied by estimating their levels in bronchoalveolar lavage fluid (BALF). Bacterial colonization, malondialdehyde (MDA) and nitrite production in BALF, and tumor necrosis factor-alpha level in serum were assessed. RESULTS The results showed that there was a significant decrease in bacterial colonization after short-term feeding with clove oil compared with the controls (p < 0.05). For tulsi oil-fed mice, the decrease in bacterial load was significant with long-term feeding (p < 0.01). The maximum decrease in MDA levels and increase in nitrite levels were noted with long-term feeding. CONCLUSION Dietary supplementation with tulsi and clove oils protects against bacterial colonization of the lungs.