benzofurans and Constriction--Pathologic

To explore the molecular biological mechanism for tanshinone II A reversing left ventricular hypertrophy, it would be studying the effect of tashinone on the endothelial nitric oxide synthase (eNOS) and protein kinase C (PKC) in the hypertrophic cadiocyte of rats suffered abdominal aorta constriction.. SD rats were operated with abdominal aorta constriction and 8 rats were done with sham surgery. After 4 weeks, all rats were divided into 4 groups: myocardial hypertrophy group, low dose tanshinone II A group (10 mg x kg(-1) x d(-1)), high dose tanshinone II A group (20 mg x kg(-1) x d(-1)) and valsartan group (10 mg x kg(-1) d(-1) intragastric administration). 8 weeks later, the rats were used to measure the left ventricular mass index (LVMI) with the tissue of left ventricle and myocardial fiber dimension (MFD) by pathological section and HE stain, to detect the nitric oxide content by nitrate reductase, to detect the genic expression of eNOS by RT-PCR and to detect the activity of protein kinase C (PKC) by Western blotting.. 1) The blood pressure in group myocardial hypertrophy [(186 +/- 13) mmHg] and tansginone II A [low and high dose (188 +/- 11,187 +/- 14) mmHg] was obviously higher than that in group sham surgery and valsartan group [vs (117 +/- 8, 136 +/- 15) mmHg, P < 0.01]. But there was no difference between group myocardial hypertrophy and group tanshinone II A (low and high dose). 2) The LVMI and MFD were obviously higher in group tanshinone II A low and high dose) and group valsartan than those in group sham surgery (P < 0.05), and lower than those in group myocardial hypertrophy (P < 0.01). 3) The NO level was obviously higher in group tanshinone II A (low and high dose) and group valsartan than that in group myocardial hypertrophy (12.78 +/- 1.66, 11.95 +/- 1.39, 12.26 +/- 2.08 vs 5.83 +/- 1.06) micromol x L(-1), (P < 0.01 ), and lower than that in group sham surgery (vs 19.35 +/- 1.47) micromol x L(-1), (P < 0.05). 4) The expressive level of eNOS mRNA and protein in myocardial hypertrophy group was less than that in other groups (P < 0.01). And valsartan group was less than tanshinone II A groups and sham surgery group (P < 0.05), but there were no difference among the two tanshinone II A groups and sham surgery group. 5) The level of PKC protein in group myocardial hypertrophy was obviously higher than that in all the other groups (1.291 +/- 0.117 vs 0.563 +/- 0.094, 0.605 +/- 0.051, 0.519 +/- 0.062, 0.827 +/- 0.086, P < 0.01), and the level in group valsartan was higher than that in group sham operation and group tanshinone II A (low and high dose).. NO/NOS system in local myocardium has close relationship with the pathological process for myocardial hypertrophy. Tanshinone II A can produce the pharmacological action to reverse myocardial hypertrophy by inhibiting the activity of PKC and promoting the genic expression of eNOS in local myocardium and the production of endogenous NO.

Topics: Animals; Aorta, Abdominal; Benzofurans; Blood Pressure; Cardiomyopathy, Hypertrophic; Constriction, Pathologic; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Endothelium, Vascular; Female; Gene Expression Regulation, Enzymologic; Heart Ventricles; Male; Myocytes, Cardiac; Nitric Oxide; Nitric Oxide Synthase; Protein Kinase C; Rats; RNA, Messenger

The synthesis of a series of 2-(phenylmethyl)-4-hydroxy-3,5-dialkylbenzofurans and their inhibitory effects against leukotriene biosynthesis and 5-lipoxygenase activity in vitro are described. Many compounds in this series were found to be potent inhibitors of LTB4 production by human polymorphonuclear leukocytes with IC50 values ranging from 7 to 100 nM. Structure-activity relationships of the series are presented. Within this series, 2-[(4'-methoxyphenyl)methyl]-4-hydroxy-3-methyl-5-propyl-7-chlorobenz ofuran (L-656,224) showed extremely potent activity, inhibiting leukotriene biosynthesis in intact human leukocytes (IC50 = 11 nM), as well as the 5-lipoxygenase reaction catalyzed by cell-free preparations from rat leukocytes (IC50 = 36 nM), human leukocytes (IC50 = 0.4 microM), and the purified enzyme from porcine leukocytes (IC50 = 0.4 microM). The compound also shows oral activity in a number of animal models in vivo.

Topics: Adult; Animals; Arachidonate Lipoxygenases; Benzofurans; Bronchi; Chemical Phenomena; Chemistry; Constriction, Pathologic; Humans; Immunoglobulin E; Leukocytes; Leukotriene B4; Lipoxygenase Inhibitors; Molecular Structure; Neutrophils; Rats; Rats, Inbred Strains; Structure-Activity Relationship