Abstract:

Objective: To investigate the in vitro antimicrobial activities of commonly used sedatives, analgesics, and muscle relaxants against Mycobacterium tuberculosis (MTB). Methods: The minimum inhibitory concentrations (MICs) of five clinically common sedatives, including sevoflurane and propofol, the analgesic dezocine, and the muscle relaxants rocuronium and atracurium, were determined against the standard MTB strain H37Rv. Colony-forming unit (CFU) counting was employed to evaluate the changes in MTB colony numbers following treatment with varying concentrations of sevoflurane, which demonstrated notable antimicrobial activity in vitro. A sputum-bacterial suspension was prepared to simulate the sputum environment, and the anti-tuberculosis activity of sevoflurane was evaluated over a 4-hour period. Additionally, the cytotoxicity of sevoflurane within 4 hours was assessed using the THP-1 cell line. Results: Propofol, dexmedetomidine, rocuronium bromide, and atracurium demonstrated no significant in vitro antibacterial activity against MTB. In contrast, sevoflurane exhibited potent antibacterial activity against H37Rv in vitro, with a MIC value of 1.25%. Further analysis showed that treatment with sevoflurane at concentrations of 3%, 6%, and 9% for 8 hours reduced MTB colony counts (log₁₀CFU) to 3.086±0.196, 4.165±0.083, and 4.162±0.100, respectively. These values were significantly lower than those of the control group (4.489±0.083), with statistical significance (F=7.630, P=0.003). The colony count (log₁₀CFU) of MTB treated with 9% sevoflurane for 48 hours was 3.000±0.000, significantly lower than that of the control group (5.077±0.191), with a statistically significant difference (F=313.300, P<0.001). In sputum suspension, treatment with 9% sevoflurane for 2 and 4 hours demonstrated significant anti-MTB activity, reducing MTB colony counts (log₁₀CFU) to 5.846±0.384 and 5.947±0.280, respectively. These values were significantly lower than those in the control group (log₁₀CFU: 6.264±0.150 and 6.331±0.162, respectively), with statistically significant differences (F=4.173, P=0.025; F=6.091, P=0.006). Furthermore, CCK-8 experiments indicated that treatment with sevoflurane at concentrations ranging from 0% to 9% maintained a cell survival rate of ≥(81.033±3.190) % in THP-1 cells over 4 hours. Conclusion: Sevoflurane exhibits strong anti-MTB activity in vitro, demonstrating short-term bacteriostatic effects under simulated conditions and maintaining favorable safety profiles.

Key words: Mycobacterium tuberculosis, Antimicrobial susceptibility tests, Hypnotics and sedatives, In vitro study, Sevoflurane