Triphenyltin fluoride in vitro inhibition of rabbit platelet collagen-induced aggregation and ATP secretion and blockade of arachidonic acid mobilization from membrane phospholipids

Effects of traditional herbal medicine, Hwaotang, on atherosclerosis using the spontaneous familial hypercholesterolemia model, Kurosawa and Kusanagi-hypercholesterolemic rabbits and the venous thrombosis rats

Hwaotang (HOT), a traditional Korean medicinal formulation, is a dried decoctum of a mixture of seven herbal medicines, consisting of Angelica gigantis Radix, Rehmanniae Radix, Paeoniae Radix, Ciniamomi Cortex, Cnidii Rhizoma, Persicae Semen and Carthami Flos. In the present study, the inhibitory effects and anti thrombic properties of HOT on the progression of atherosclerotic lesions were studied using the spontaneous familial hypercholesterolemia (FH) model, Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits and rats. Changes in blood chemistry, pathology and low-density lipoprotein (LDL) oxidation were measured in a control and HOT group. In the control group, the area of atheromatous plaques of the aorta progressed between week 12 (36.65%) and week 14 (46.22%). This progression of atherosclerotic lesions did not occur in the HOT-treated group after 12 (24.24%) and 14 (23.34%) weeks. Antioxidative effects on LDL were seen in the HOT in weeks 12 and 14. HOT improved the hypercholesterolemia in the KHC rabbits. On the other hand, HOT and five of the seven herbs, except Cnidii Rhizoma and Carthami Flos, inhibited the endotoxin-induced hepatic venous thrombosis in high cholesterol diet-treated rats. However, Ciniamomi Cortex showed a very weak inhibitory effect on the endotoxin-induced hepatic venous thrombosis. The extract also inhibited the endotoxin-induced decrease in blood platelets and fibrinogen, and endotoxin-induced increase in fibrin degradation products (FDP) on disseminated intravascular coagulation in normal rats. In conclusion, these results suggest that HOT has inhibitory effects on the development of atheromatous plaque formation in spontaneous FH rabbits. It is also suggested that the antioxidative effects of HOT on LDL led to the beneficial effects observed in this study. The protection by HOT and its herbs on the artificially induced ischemic infarction might be related to their inhibitory effects on disseminated intravascular coagulation, platelet coagulation and thrombotic action.

Anti-thrombic activity of Korean herbal medicine, Dae-Jo-Whan and its herbs

The anti-thrombic properties of the Korean herbal medicine, Dae-Jo-Hwan (DJW), which is consisted of 11 herbs (indicated as concentrations) of Rehmanniae radix 24%, Hominis placenta 5%, Testudinis carapax 9%, Eucommiae cortex 9%, Asparagi radix 9%, Phellodendri cortex 9%, Achyranthis radix 7%, Liriopis tuber 7%, Angelicae sinensis radix 7%, Ginseng radix 6%, and Schizandrae fructus 3%, were investigated. The extracts of DJW and its 11 herbs, except G. radix, A. sinensis radix and S. Fructus, inhibited the endotoxin-induced hepatic venous thrombosis in high cholesterol diet-treated rats. Also the extract inhibited the endotoxin-induced decrease in blood platelets and fibrinogen, and endotoxin-induced increase in fibrin degradation products (FDP) on disseminated intravascular coagulation in normal rats. In in vitro experiments, the extract was shown to have inhibitory effect on collagen- and ADP-induced blood platelet aggregation, on thrombin-induced conversion of fibrinogen to fibrin and on the activity of plasminogen or plasmin. In conclusion, the protection of extracts of Korean herbs on the ischemic infarction induced artificially might be related to their inhibitory effects on DIC, platelet coagulation and thrombic action.

Effects of a Korean herbal formulation, Silsosangami, consisting of seven medicinal herbs, and its seven herbs on endotoxin-induced experimental thrombosis in rats

A traditional Korean medicine, Silsosangami (SSG), consisting of seven different herbs of Typhae Pollen, Pteropi Faeces, Paeoniae Radicis rubra, Cnidii Rhizoma, Persicae Semen, Carthami Flos and Curcumae Tuber, has been reported to have a hypolipidemic effect in human subjects. In the present study, the inhibitory effects of SSG on a thrombosis in rats, induced by endotoxin treatment were examined. The anti-thrombic properties of SSG were also investigated with respect to blood parameters. The extracts of SSG and five of the seven herbs, except Cnidii Rhizoma and Carthami Flos, inhibited both endotoxin-induced disseminated intravascular coagulation (DIC) and thrombosis in rats. The extract also inhibited the endotoxin-induced decrease in blood platelets and fibrinogen, and the endotoxin-induced increase in fibrin degradation products (FDP) on disseminated intravascular coagulation in normal rats. In conclusion, the artificially induced, protective effects of SSG on ischemic infarction might be related to their inhibitory effects on DIC, platelet coagulation and thrombotic action.

Effect of triphenyltin chloride on the release of histamine from mast cells

The effects of triphenyltin chloride (TPTC) on the release of histamine from rat and mouse mast cells in vitro and in vivo were investigated. The results obtained are summarized as follows: (a) At doses between 1 and 3 mg/kg, TPTC inhibited the dye leakage due to passive cutaneous anaphylaxis mediated by IgE antibody in mouse ear. At the same doses, TPTC inhibited the swelling due to reversed cutaneous anaphylaxis mediated by IgG antibody in rat. However, TPTC did not affect dye leakage due to histamine, serotonin, and LTC4 in rat skin; (b) Histamine release by antigen and IgE antibody in rat peritoneal cavity was inhibited by the administration of TPTC at doses between 0.3 and 3 mg/kg; (c) Histamine release by calcium ionophore A 23187 from purified rat peritoneal mast cells in vitro was inhibited by TPTC at concentrations between 10(-7) and 10(-6) M. At the same concentration, TPTC, itself, caused neither the release of histamine nor any change in cell viability which was supported by the activity of lactate dehydrogenase (LDH) from purified rat peritoneal mast cells. All this evidence suggests that TPTC has an inhibitory effect on the release of histamine from mast cells without direct cytotoxicity.

Inhibitory effects of tryptophan pyrolysis products on human platelet aggregation through inhibition of prostaglandin endoperoxide synthetase

To determine the effects of the carcinogenic heterocyclic amines on the stimulus-reaction system in cells, the effects of several such amines, including 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), on human platelet aggregation and of Trp-P-1 and Trp-P-2 on human polymorphonuclear leucocyte aggregation were investigated. Of the carcinogens studied, only Trp-P-1 and Trp-P-2 had potent inhibitory effects on human platelet aggregation induced by sodium arachidonate. The concentrations of Trp-P-1 and Trp-P-2 causing 50% inhibition of human platelet aggregation induced by sodium arachidonate were 15 and 25 microM, respectively. The heterocyclic amines examined had no significant effects on human polymorphonuclear leucocyte aggregation. Moreover, radiochemical studies of arachidonate metabolism showed that Trp-P-1 and Trp-P-2 inhibited, in a dose-dependent manner, the formation of cyclooxygenase products in platelets induced by sodium arachidonate. These results indicate that Trp-P-1 and Trp-P-2 have potent inhibitory effects on prostaglandin endoperoxide synthetase in the stimulus-reaction system of human platelets.

Miconazole inhibition of platelet aggregation by inhibiting cyclooxygenase

Platelet dysfunction was found in rabbits to which a dose of miconazole nitrate (1.6 mg/kg body wt) therapeutic for human subjects had been given intravenously. The present experiments were conducted to elucidate the mechanism of inhibitory effects of miconazole on platelet function. After administration of a single dose of miconazole, rabbit platelet aggregation induced by collagen and sodium arachidonate was inhibited significantly for approximately 24 hr. On the other hand, hypertriglycemia, one of the major side effects of this drug, was not seen during 2 days of observations, nor were any other outstanding manifestations observed. In in vitro experiments, miconazole nitrate (10 microM) also significantly inhibited rabbit and human platelet aggregation (P less than 0.01). Biochemical analyses revealed that the stimulant-induced formation of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2), metabolites via cyclooxygenase, was inhibited by miconazole nitrate in both human and rabbit platelets in vitro. PGE2 production was decreased dose-dependently with the increase of miconazole concentration (10 to 100 microM), and the decrease was in parallel with a decrease of TXB2 production. In addition, malondialdehyde (MDA) production of human and rabbit platelets induced by exogenous arachidonate and collagen was also inhibited significantly by miconazole. Chromatographic studies showed that the amount of 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid (HETE), a metabolite via lipoxygenase, was increased markedly in accordance with the miconazole-induced decrease of TXB2 and 12-L-hydroxy-5,8,10-heptadecatrienoic acid (HHT) formation in both human and rabbit platelets. These results indicate that miconazole nitrate inhibits platelet cyclooxygenase, without affecting the stimulant-induced release of arachidonic acid from platelet phospholipids. Use of this drug in the treatment of systemic fungal infection appears to be increasing. Careful attention should be paid to the inhibitory effects of miconazole on platelet function, especially in the case of intravenous treatment.