RESUMO
Objective To study the effect of 5-lipoxygenase(5-LOX) inhibitor nordihyroguaiaretic acid (NDGA) combined the selective cyclooxygenase-2 (COX-2) inhibitor Celecoxib on the apoptosis of human colon carcinoma cell line HT-29. Methods Different concentration of NDGA and Celecoxib combinations were used to process cancer cell, and thiazolyl blue tetrazlium bromide (MTT) and phase contrast microscope and Annexin V/PI fluorescence staining and reverse transcription polymerase chain reaction (RT-PCR) were used to study the proliferation inhibited effect and apoptosis induced effect caused by combination of NDGA combined Celecoxib. Results MTT results showed that the viability of NDGA group, Celecoxib group and the group of NDGA combined Celecoxib (0.432±0.024,0.425±0.013,0.303±0.014 vs 0.693±0.018,t＝18.79,25.75,37.64,P＜0.01) was obviously lower than control group. The group of NDGA combined Celecoxib was significantly lower than NDGA group or Celecoxib group (t＝10.21, 14.14,P＜0.01). Under inverted phase contrast microscope, cell morphology significantly changed, and the group of NDGA combined Celecoxib changed most obviously. Apoptosis was observed by laser scanning confocal microscope (LSM) after NDGA and Celecoxib were used to process the HT-29. RT-PCR showed that up-regulation of Caspase-3 after treatment, and the combination of two drugs increased the most. Conclusions NDGA combined Celecoxib inhibited proliferation and induced apoptosis in human colon carcinoma cell line HT-29, and combined therapy had better effect than that of any drug used separate-ly. The mechanism may be associated with up-regulation of Caspase-3.
RESUMO
Objective To study the preventive effect of lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) on chronic atrophic gastritis (CAG). Methods To construct CAG rat model, 72 male rats were randomly divided into 6 groups, including normal group, CAG model group, NDGA group with different dose and positive groups (folacin). After feeding for 24 weeks, all rats were executed, their stomach mucous membrane was picked out and stained with H.E. The expression of 5-LOX and P16 protein in mucous membrane epithelia cells were detected by immunohistochemistry. Results The CAG incidence rate in model group was significant higher than normal group (77.8% vs 0% , P ＜0. 05), which indicated that C AG model rat was successfully established. The CAG incidence rate of model group was significantly higher than NDGA groups (77.8% vs 25% ,27.3% ,25%, P＜0.05), while no significant difference was found between positive group and NDGA groups (30% vs 25% ,27.3% ,25% , P＞0.05) .The expression of 5-lox in model group was higher than NDGA groups (44% vs 25% ,27% ,25%, P＜0.05). The expression of P16 protein in model group was lower than NDGA groups (66.7% vs 83.3% ,81.8% ,83.3%,P＜0.05) , and there were no significant differences between NDGA groups and positive group (83. 3%,81.8% ,83.3% vs 80%, P＞0.05). Conclusions NDGA could prevent the occurrence of N-ethyl-N-nitro-N nitrosoguanidine-induced chronic atrophic gastritis in rat. NDGA could down-regulate the expression of 5-LOX and up-regulate the expression of P16 in stomach mucous membrane of N-ethyl-N-nitro -N-nitrosoguanidine-induced chronic atrophic gastritis in rat.