ABSTRACT
Objective To observe the effects of Soyasaponins on inflammatory factors, antioxidant activity and exercise ability in rats with severe heat stroke. Methods Eighty male Sprague-Dawley (SD) rats were randomly divided into normal control group, heat shock model group, saline control group and Soyasaponin group, The rats that died during the experiment or with a low rectal temperature (< 41℃) were excluded, and finally 54 rats were included, 18 rats remaining in each group. The rats in the heat shock model group were placed in the simulated hot climate animal cabin at 30 ℃, and the temperature within 30 minutes was raised to 39 ℃ in the cabin with 65% humidity; in the mean time, the rat models of heat shock were replicated under the following situations: let the rats exercise on a treadmill with running speed set at 15 m/min, slope degree 0°, once running for 8 minutes, interval 2 minutes and the heat shock time was 90 minutes, the rats in the normal control group were fed in an environment with temperature ranging from 23-25 ℃ and relative humidity ranging from 50%-70%. After the establishment of models, the saline control group and Soyasaponin group were given daily saline and Soyasaponin (10 mg/kg) respectively by gavage for 3 consecutive months, while the heat shock model group was not given any treatment. The femoral artery blood was collected 24 hours after the rats left the cabin. The serum levels of interleukins (IL-6, IL-1β), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), malonaldehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) were measured by enzyme-linked immunosorbent (ELISA) and the contents of serum hemoglobin (Hb), serum urea (BUN), lactate dehydrogenase (LDH) and blood lactic acid (Lac) were measured by automatie biochemical analyzer. Results The levels of IL-6, IL-1β, TNF-α, IFN-γ, MDA, Hb, BUN, LDH, Lac in heat shock model group were significantly higher than those of the normal control group [IL-6 (ng/L): 86.17±4.82 vs. 12.60±3.49, IL-1β (ng/L): 83.00±5.98 vs. 15.70±3.64, TNF-α (ng/L): 72.22±6.93 vs. 13.75±2.69, IFN-γ (ng/L): 36.22±3.02 vs. 7.35±1.60, MDA (nmol/mg): 19.78±4.56 vs. 6.40±1.35, Hb (g/L): 136.22±1.93 vs. 126.75±5.84, BUN (mmol/L):21.06±3.44 vs. 5.65±1.35, LDH (μmoL·s-1·L-1): 9.65±0.83 vs. 2.12±0.17, Lac (mmol/L): 552.56±78.33 vs. 1.32±0.18, all P ＜ 0.05], SOD and GSH-Px were significantly lower than those in normal control group [SOD (kU/L):97.89±10.57 vs. 126.65±11.35, GSH-Px (kU/L): 19.22±2.58 vs. 43.45±4.02]; however, the levels of IL-6, IL-1β, TNF-α, IFN-γ, MDA, BUN, LDH and Lac in Soyasaponin group were significantly lower than those in heat shock model group [IL-6 (ng/L): 45.28±3.54 vs. 86.17±4.82, IL-1β (ng/L): 41.61±2.93 vs. 83.00±5.98, TNF-α (ng/L):37.22±2.46 vs. 72.22±6.93, IFN-γ (ng/L): 19.22±2.60 vs. 36.22±3.02, MDA (nmol/mg): 11.28±1.74 vs. 19.78±4.56, BUN (mmol/L): 11.78±2.13 vs. 21.06±3.44, LDH (μmoL·s-1·L-1): 3.70±0.26 vs. 9.65±0.83, Lac (mmol/L): 274.56±59.08 vs. 552.56±78.33, all P < 0.01], SOD, GSH-Px and Hb were significantly higher than those of heat shock model group [SOD (kU/L): 116.11±11.28 vs. 97.89±10.57, GSH-Px (kU/L): 31.17±2.90 vs. 19.22±2.58, Hb (g/L): 141.33±3.79 vs. 136.22±1.93, all P < 0.01]; there were no significant statistical differences in above indexes between heat shock model group and saline control group (all P > 0.05). Conclusion After heat shock and exercise management, the production and release of inflammatory factors are increased, and the level of lipid peroxidation was elevated in rats. The Soyasaponin can improve the ability to withstand heat shock and strong exercise by reducing the production and release of inflammatory factors and lipid peroxidation in the rats with severe heatstroke.