Effect of aloe polysaccharides pretreatment on the cerebral inflammatory response and lipid peroxidation in severe hemorrhagic shock rats first entering high altitude

Abstract

To investigate the effect of aloe polysaccharides pretreatment on the cerebral inflammatory response and lipid peroxidation in severe hemorrhagic shock rats first entering high altitude. Forty healthy male SD rats weighing 250-300 g were randomly divided into 5 groups (n = 8 each): sham group, shock group, AP group was further divided into 3 subgroups (AP1 0.75 mg/kg; AP2 1.50 mg/kg; AP3 3.00 mg/kg). The different doses AP were given iv respectively at 30 min before hemorrhagic shock. The mean blood pressure (MAP) was maintained at (35 ± 5) mmHg (1 mmHg = 0.133 kPa) for 60 minutes. The animals were killed at 2 hours after resuscitation. Blood samples were obtained from femoral artery for detecting tumor necrosis factor α (TNF-α), IL-6 and IL-10 concentrations; the frontal and parietal lobes brain and the hippocampus were separated from brain tissues on the ice for detecting superoxide dismutase (SOD) activity and myeloperoxidase (MPO) activity, malondialdehyde (MDA) concentration, brain Wet-dry weight ratio (W/D). Compared with sham group, hemorrhagic shock significantly increased serum TNF-α ((76 ± 11) ng/L), IL-6 ((1303 ± 141) ng/L) and IL-10 concentrations ((95 ± 14) ng/L), MPO activity ((20.72 ± 2.28)×10(-2) U/g) and MDA concentration ((80 ± 13) nmol/mgprot) in the brain tissue and brain W/D (6.21 ± 0.18) (t = 6.928 - 14.565, P < 0.05), while SOD activity ((56 ± 11) U/mgprot) decreased significantly (t = -5.374, P < 0.05). There were no significant difference between shock and AP1 groups. AP2 group significantly inhibited hemorrhagic shock-induced increase serum TNF-α ((54 ± 12) ng/L), IL-6 ((846 ± 78) ng/L) and IL-10 concentrations ((66 ± 11) ng/L), MPO activity ((13.13 ± 1.23)×10(-2) U/g) and MDA concentration ((56 ± 9) nmol/mgprot) in the brain tissue and brain W/D (5.71 ± 0.18) (t = -6.905 - -3.357, P < 0.05), while SOD activity ((86 ± 12) U/mgprot) increased significantly compared to shock group (t = 4.240, P < 0.05). There were no significant difference between AP2 and AP3 groups. AP pretreatment can attenuate the cerebral ischemia and reperfusion injury in severe traumatic-hemorrhagic rats first entering high altitude through inhibiting systemic inflammatory response and leukocyte aggregation and lipid peroxidation in the brain.