| Objective:To study the acute, chronic toxicity and genetoxicity of moxa smoke and to evaluate its safety by principles of toxicology.Methods:Animals were exposed in an automatic dynamic exposure devic, which display and control the exposed temperature, humidity, pressure, oxygen and the concentration of moxa smoke for acute toxicity and chronic toxicity study. Moxibustion Smoke was sampled by BHF7-MINIVOLTM-PM2.5and melted in DMSO and then used in vitro test, such as cytotoxicity test, chromosomal aberration tests, micronucleus test&Ames test.1Acute toxicology study:KM mice were tested in exposure devic at60%(opacity) and80%for lethal time of50%(LT50); Wistar rats were randomly divided into five groups, were tested in exposure devic at moxa smoke dosages of75%,80%,85%,90%for2h, for lethal dose of50%(LD50).2Chronic toxicity study:In Chronic toxicity study, rats were randomly divided into four groups to evaluate the toxic effects at different dosages in12weeks,24weeks after exposure and12weeks after post-exposure. Toxic reaction, dead rats number, tissue pathology, organ/body weight, haematological parameters, clinical chemistry parameters, routine urinalysis, and pulmonary function, expression of SOD, MDA, IL-2, IL-4, IL-10, IFN-y in lung was observed.3Cytotoxicity test:Different consentration treated the Chinese hamster ovary cells (CHO) cells, which were cultured in vitro, and harvested24h after MSC treatment by using MTT method, and then obtained the IC50value in CHO, to provide data for the latter the experiment.4Chromosomal aberration tests:To test the activity of MSC in vitro genetic toxicology test systems with the incidence of chromosomal aberrations in CHO. We incubated CHO with S9mix (+S9) and without S9mix (-S9) and harvested24h after treatment, and then prepared and analysed metaphase chromosome samples with addition of colchicine. Treatment group:control group-S9, mitomycin C-S9,1/2IC50MSC-S9,1/4IC50MSC-S9,1/8IC50MSC-S9, control group+S9, cyclophosphamide+S9,1/2IC50MSC+S9,1/4IC50MSC+S9,1/8IC50MSC+S9.5Micronucleus test:To test the activity of MSC in vitro genetic toxicology test systems with the high frequency of micronucleus in CHO. We incubated CHO and harvested24h after treatment, and prepared and analysed samples with addition of cytochalasin B. Treatment group:control group, cyclophosphamide group,1/2IC50MSC,1/4IC50MSC.1/8IC50MSC.6Ames test:To screen the activity of MSC in vitro genetic toxicology test systems in mutagenicity using the Ames’test. Using the plate incorporation assay, MSC were assayed for mutagenicity employing several histidine dependent salmonella strains (TA97,TA98, TA100and TA102) both with and without metabolic activation using a liver fraction (S9).Treatment group:control group-S9,62.5-S9,125-S9,250-S9,500-S9,1000-S9μg/dish, Positive control, control group+S9,62.5+S9,125+S9,250+S9,500+S9,1000+S9μg/dish, Positive control+S9. Each set up three plates. When a mutagen is added to the plate, the number of revertant colonies per plate increased, and usually is equal to or more than2times the number of spontaneously induced revertant colonies per plate, usually in a dose-related manner.Results:Results of research on toxicology of moxa smoke were as follows:1Acute toxicity study:In the acute study, the lethal dosage of50%(LD50) for a2h-exposure to moxa smoke was86.247%in wistar rats, and the lethal time of50%for85%and65%is45.41min and209.96min in KM mice.2Chronic toxicity study:There were no deaths in the chronic study. There were, however, histopathological changes in the lungs in all exposed groups although there were no functional pulmonary changes compared to control. These histopathological alterations were unchanged at36weeks. No significant abnormalities in body weight at the low dosage were observed when compared to control. however, the middle and high dosage produced decreases in body mass but returned to normal at36weeks. No significant abnormalities in blood count, blood chemistry, or routine urinalysis were observed.3Cytotoxicity test:For MSC the IC50value in Chinese hamster ovary cells (CHO) harvested24h after treatment obtained using MTS/PMS was0.087mg/ml.4Chromosomal aberration tests:Chromosomal Aberration Tests:The incidence of chromosomal aberrations in CHO, in descending order, were CP+S9, MSC+S9, MMC+S9, control group+S9, MSC-S9, control group-S9. MSC has biological activity and showed some cytotoxicity at high-dose. MSC were positive when they were activated with the S9mix.5Micronucleus test:1/2IC50MSC,1/4IC50MSC,1/8IC50MSC showed higher frequency of micronucleus in CHO compared to control group.6Ames test:Without S-9, MSC showed mutagenic activity that was not enhanced, while, with S-9MSC were found to be mutagenic for strain TA98rather than TA97,TA100,TA102. Conclusion This Ames test screened MSC a mutagenic potential. Conclusion:1Moxa smoke is not hazardous waste, and continued exposure of high concentrations of moxa smoke killed rats and mice, mainly due to CO.2the security of moxa smoke is up to the concentrations of it. Low concentration had no significant effect, while, medium and high concentrations damaged the lungs and respiratory system, affected metabolism, immune system and showed no significant effect on the blood cells, liver and kidney function. The low concentration is the NOAEL which is10%and with the respirable particulate matter level28.4mg/m3. For human the expected limit concentration is2.8mg/m3.3with high concentration and long exposure time, the moxa smoke may have a genetic toxicity, the concentration and time of exposure should be controled.4The current moxibustion environment should be improved in ventilation to enhance the security of it. |
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