A combined dynamic inhalation device designed for moxa-smoking toxicity testing

ObjectiveTo design a combined dynamic inhalation device for testing the toxicity induced by moxa smoking.MethodsThe new apparatus (Patent No. 201120101911.5) includes air renewal and recycling systems, a gas generating device, a gas control unit, and a device to measure and control temperature and humidity. Sprague-dawley rats were tested for acute and sub-chronic toxicity after exposure to moxa-burning smoke.ResultsWe found an LC50 of 1.2 × 104 mg/m3 in the acute toxicity assays. In sub-chronic toxicity tests the organ coefficients studied showed no significant differences within rats groups of the same gender after treatment with moxa smoke or a month of recovery. However, mean gray degree of lung 70 heat shock protein (HSP70) was significantly elevated in the high dose group in comparison with the low dose group (P < 0.05); mean gray degree, mean optical density, gross area of HSP70 in other organs and caspase-9 parameters showed no significant differences between groups.ConclusionThese results suggest that moxa smoke had no overt toxicity in rats. This work provides evidence and reference for the design of dynamic inhalation exposure systems.