Experimental Study On The Pharmacodynamics Of Patchouli Oil In Treatment Of Bacteria-induced Acute Upper Respiratory Tract Infection

Objective:To investigate the effect and possible mechanism of patchouli oil against acute upper respiratory tract infection (AURTI) induced by bacteria.Methods:1. In vitro experiments were carried out to observe the antibacterial activities of patchouli oil on standard strains Staphylococcus aureus ATCC 25923, methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 and clinical isolated strains Staphylococcus aureus J2, J3, J14, J16, J17, J20.2. Using MRSA to infect mice, and then treating with patchouli oil, to detect the pathological changes of nasal mucosa, trachea and lung, and the alterations of colony count of MRSA in nasopharynx of mice.3. Rabbits fever model evoked by lipopolysaccharide (LPS) were used to observe the effect of Patchouli oil on body temperature, the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the serum, and the levels of prostaglandin E2 (PGE2) and cyclic adenosine monophosphate (cAMP) in the hypothalamus of rabbits.Results:1. The antibacterial activities of patchouli oil on Staphylococcus aureus ATCC 25923, MRSA ATCC 43300 and Staphylococcus aureus J2, J3, J14, J16, J17, J20 were strong. The minimum inhibitory concentrations (MICs) of patchouli oil on Staphylococcus aureus J2 and the other bacteria were 0.99 mg/mL and 0.49 mg/mL, respectively.2. Each dosage groups of patchouli oil (12.65,6.325,3.1625 mg/kg) could alleviate the pathological changes, erythrocyte diapedesis and inflammatory cells infiltration in nasal mucosa of mice with AURTI induced by MRSA. The amount of MRSA significantly upregulated in nasopharynx of mice after MRSA infections, however which was notably inhibited in each dosage groups of patchouli oil.3. Patchouli oil (20.24,10.12,5.06 mg/kg) notably inhibited the increased body temperature in the febrile rabbits. From 1.5 h to 5.5 h after administration, the increased body temperatures were (1.06±1.55), (1.62±±1.36), (1.38±1.22), (0.98± 0.98) and (0.48±0.95) ℃ in high patchouli oil group, respectively. From 3.5 to 5.5 h after administration, the elevated body temperatures were (1.47±0.73), (1.15± 0.68) and (0.63±0.54)℃ in middle patchouli oil group, respectively. A tendency of downregulation of the elevated body temperatures was observed at every time points after administration in low patchouli oil group. Patchouli oil significantly lowered the increased levels of TNF-a in the serum and cAMP content in the hypothalamus, and attenuated the elevatory tendency of the IL-1β level in the serum and PGE2 level in the hypothalamus.Conclusions:Patchouli oil has positive effects on AURTI model mice stimulated by bacteria. It might be related to inhibit pathogenic bacteria directly, alleviate the pathological changes, erythrocyte diapedesis and inflammatory cells infiltration in nasal mucosa. It also might be related to the antipyretic effects of patchouli oil through of inhibition of the levels of TNF-a in the serum and cAMP in the hypothalamus.