摘要:
OBJECTIVE To explore the toxicity and mechanism of total annonaceous acetogenins (ACG) of the seeds from Annona squamosa Linn.in rats.METHODS The rats were randomly divided into solvent control (0.5% CMC-Na),total ACG 7 and 14 mg·kg-1 groups.Rats were ig given ACG 7 and 14 mg·kg-1,once daily,for 28 d.The histological sections of heart,liver and kidney were observed with HE staining under an optical microscope.Then,serum indexes including alanine transaminase (ALT),aspartate aminotransferase (AST),blood urea nitrogen (BUN),creatinine (Cr) and creatine kinase (CK) were detected by automatic biochemical analyzer.Besides,probable mechanisms were discussed by detecting the concentrations of protein,the activity of mitochondrial complex Ⅰ and ATP levels with BCA method,spectrophotometry and fluorescein determination method.Finally,the concentrations of intracellular calcium and reactive oxygen species (ROS) were detected by fluorescent probe method.RESULTS There was slight edema on livers of rats in ACG 14 mg·kg-1 group.Compared with solvent control group,ALT level in total ACG 14 mg· kg-1 group significantly increased from (50.0 ± 1.4) to (59.0 ±2.6)U·L-1 (P<0.05),AST level from (126 ±11) to (176 ±12) U·L-1 (P<0.05),BUN level from (6.13 ± 0.15) to (12.9 ± 2.05) mmol· L-1 (P < 0.01),and CK level from 293 ± 13 to (480 ±97)U· L-1(P <0.05).The Cr level showed statistically significant difference from solvent control group.The mitochondrial complex Ⅰ activity in heart from total ACG 14 mg· kg-1 group obviously decreased from 22.6 ±4.9 to (7.5 ± 1.7) μmol· g-1 protein,min-1 (P < 0.01),from 72 ± 10 to (54 ± 10)μmol·g-1protein·min-1 in liver(P<0.01),and 34 ±4 to (26 ±6) μmol·g-1protein·min-1 in kidney (P<0.05).ATP level in heart tissue decreased from 10.4 ±2.1 to (2.2 ±3.4)nmol·L-1 (P<0.01),while 6.8 ±1.6 to (3.4 ±1.2)nmol·L-1 in liver tissue(P<0.05),and 12.5 ±3.4 to (5.5 ±1.1)nmol·L-1 in kidney tissue(P <0.05) in total ACG 14 mg·kg-1 group.Moreover,the concentrations of intracellular calcium (fluorescence intensity) in heart of total ACG 14 mg·kg-1 group increased from 7.37 ±0.64 in solvent control group to 9.06 ±0.08,ROS (fluorescence intensity) from 14.8 ±4.1 to 110.0 ± 19.0.Compared with solvent control group,the above indexes had no obvious change in total ACG 7 mg· kg-1 group.CONCLUSION There is significant toxicity existing in heart,liver and kidney after total ACG administered,which might result from the ATP level dropping and the concentrations of intracellular calcium and ROS rising by inhibiting the activity of complex Ⅰ in rats.%目的 观察番荔枝总内酯对大鼠的毒性作用,初步探讨其毒性机制.方法 将雄性SD大鼠随机分为溶剂对照、番荔枝总内酯7和14 mg·kg-1组,分别ig给药,每天1次,连续4周,末次给药1h后取血,处死大鼠.HE染色观察大鼠心、肝和肾组织病理变化;全自动生化分析仪检测血清中丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、血清尿素氮(BUN)、肌酐(Cr)和肌酸激酶(CK)水平;BCA法、分光光度法和荧光素法分别测定心、肝和肾线粒体中蛋白质浓度、线粒体复合物Ⅰ活性和ATP含量;荧光探针法检测组织中Ca2+和活性氧类(ROS)浓度.结果 番荔枝总内酯14 mg·kg-1组大鼠肝组织中央静脉周围细胞轻微肿胀;与溶剂对照组比较,血清ALT,AST,BUN和CK水平显著升高,分别由溶剂对照组的(50.0±1.4)U·L-1,(126±11)U·L-1,(6.13±0.15) mmol· L-1和(293±13)U·L-1升高到(59.0±2.6)U·L-1(P<0.05),(176±12)U·L-1(P<0.05),(12.9±2.05)mmol·L-1(P<0.01)和(480±97)U·L-1(P<0.05),血清Cr水平无明显变化.心、肝和肾组织线粒体复合物Ⅰ活性分别由溶剂对照组的(22.6±4.9),(72±10)和(34±4) μmol·g-1蛋白·min-1降低到(7.5±1.7),(54±10)和(26±6)μmol·g-1蛋白·min-1(P<0.05,P<0.01);心、肝和肾组织ATP含量由溶剂对照组的(10.4±2.1),(6.8±1.6)和(12.5±3.4) nmol· L-1降低至(2.2±3.4),(3.4±1.2)和(5.5±1.1)nmol·L-1 (P<0.05,P<0.01);心肌细胞中Ca2+和ROS浓度增加,荧光强度分别由7.37±0.64和14.8±4.1增加到9.06±0.08和110.0±19.0(P<0.05,P<0.01),肝和肾细胞内Ca2+和ROS浓度无明显变化.番荔枝总内酯7mg·kg-1组上述指标无明显变化.结论 番荔枝总内酯对大鼠心、肝和肾具有一定的毒性,其作用机制可能是降低心、肝和肾组织中线粒体复合物Ⅰ的活性和ATP含量,升高组织细胞内Ca2+和ROS浓度,引起组织细胞损伤.