ObjectiveTo understand the influence of hot spring bathing intervention on population's antioxidation functions.

MethodsThree typical types of hot spring(metasilicic acid type, warm mineral type and temperature type)in Guizhou Province were selected for investigation. According to the inclusion-exclusion criteria, questionnaires and physical examinations results, 421 individuals were selected as observation subjects for hot spring bathing intervention, of which 311 subjects completed 40 to 50 minutes of intervention once a day, 5 days a week, and for 4 weeks. Two physical examinations before and after the intervention were conducted for the 311 subjects. The fasting venous blood samples on the mornings of two physical examinations were collected and the serum was separated. Levels of serum oxidative stress-related parameters including total superoxide dismutase(T-SOD), copper zinc superoxide dismutase(Cu-Zn SOD), glutathione sulfur transferases(GSTs)glutathione peroxidase(GSH-px), sulfhydryl(-SH)and malondialdehyde(MDA)were measured by enzymatical methods.

ResultsThe overall comparison showed that compared with before the bathing intervention, the levels of antioxidant enzymes including T-SOD, Cu-Zn SOD, GSTs and GSH-px significantly increased in serum after the intervention(all P < 0.05). There was an increasing trend of serum -SH level after the intervention, but with no statistical differences were seen(P > 0.05). MDA, a product of lipid peroxidation, significantly decreased in serum after the intervention(P < 0.05). The results of classified comparison showed that the effects of different hot spring types on antioxidant enzymes were different. Metasilicic acid type significantly increased the activities of GSTs and GSH-px in serum(all P < 0.05), warm mineral type significantly increased the activities of T-SOD and Cu-Zn SOD in serum(all P < 0.05), and temperature type significantly increased the activities of T-SOD, Cu-Zn SOD and GSTs in serum(all P < 0.05). There were increasing trends of serum -SH levels after bathing intervention of all three hot spring types, but no statistical differences were seen(all P > 0.05). The serum MDA levels decreased significantly after bathing intervention of all three types of hot springs(all P < 0.05).

ConclusionOverall, bathing intervention of hot springs can improve the activities of antioxidant enzymes and reduce lipid peroxidation products in population. The results of oxidative stress parameters are slightly different in different types of hot springs. The subjects mainly show the elevation of glutathione related enzyme(GSTs and GSH-px)activities after intervention of metasilicic acid type, the elevation of superoxide dismutase(SOD)activities after intervention of warm mineral type and temperature type, and the decline of lipid peroxidation levels after intervention of all three types. It suggests that hot spring bathing may have certain effects on improving the body's antioxidation functions.