Protective Effects Of The Lyophiled Powder Injection Of Bear Bile On Vascular Endothelial Cells Induced By Hypoxia-reoxygenation Injury

Objective: To study the protective effects of the lyophiled powder injection of bear bile on cultured vascular epithelial cells (VEC) induced by hypoxia-reaxygenation injury, nitric oxide (NO) and lactic dehydrogenase (LDH) produced and intercellular adhesion molecule (ICAM-1) by epithelial cells, and to further study the bear bile for mechanisms of anti -atherosclerosis. Methods: By using primary culture of human umbilical vein endothelial cells (HUVEC) in vitro, the VECs were divided into three groups: (1) normal group: normal VECs, (2) hypoxia-reoxygenation group: VECs were treated with 1 mM sodium dithionite and continue to be cultured for 12 hours by adding whole M199, and (3) bear bile group: VECs were continuously cultured with different concentrations of the bear bile after hypoxia. The morphological changes of VEC in each group were observed by the inverted microscope, and the expression of ICAM-1 in each group was detected by immunocytochemistry. The optical density (OD) value of cells was detected by MTT colorimetric method, content of MDA and NO in the supernatant fluid of cultured cells was detected by spectrophotometer, and the transudatory content of LDH was detected by automatic biochemistry analyzer. Results: The results detected by immumocytochemistry showed that the expression of ICAM-1 was very strong in the hypoxia-reoxygenation group, but one was weak in the normal group and bear bile group. In addition, MTT assay showed that bear bile had the protectiveeffects for VECs induced by hypoxia-reaxygenation injury in 60-160ug/ml of concentration. The OD value was obviously decreased in the hypoxia-reoxygenation group, but one was increased in the normal and bear bile groups and was highest at 80 |ig/ml of bear bile concentration. The OD value had significant difference (P<0.01) between normal group (0.459 + 0.05), bear bile group (0,344 + 0.098) and hypoxia-reoxygenation group (0.21+0.029). The content of MDA and NO in the supernatant fluid of cultured cells also had significant different between the hypoxia-reoxygenation group and normal group, bear bile groups. Namely, MDA content (4.97 + 0.39 nmol/ml) was increased and NO content (69.44 + 14.34 umol/L) was decreased in the hypoxia-reoxygenation group, in contrast, MDA content (1.46 + 0.21 nmol/ml and 1.77 + 0.21 nmol/ml) was decreased and NO contents (102.08 + 4.29umol/L and 107.08 + 37.88umol/L) was increased in the normal and bear bile groups. The transudatory content of LDH had significant different (P<0.01) between the hypoxia-reoxygenation group and normal group, bear bile groups. but there had no significant difference (P>0.05) in the other groups except there had significant difference (P<0.05) between the bear bile group and hypoxia-reoxygenation group at 60ug/ml of concentration of bear bile. Conclusions: The results indicate that the lyophiled powder injection of bear bile has protective effects for the HUVEC induced by hypoxia-reaxygenation injury and anti-anoxic injury by the mechanisms of abating the lipid peroxidation of cell, counterpoising the content of NO and decreasing over expression of ICAM-1.