Search PubMed⌕ Search

Biomedical subjects

S Arichi

Publications and source records attributed to S Arichi.

At least 73 records · Page 4Linked to original sources
PubMed1982

Selective inhibition of platelet lipoxygenase by esculetin.

The effects of coumarin and its derivatives on rat platelet lipoxygenase and cyclooxygenase activities were studied. Esculetin (6,7-dihydroxycoumarin) was found to inhibit the lipoxygenase more strongly than the cyclooxygenase; its concentration for 50% inhibition (IC50) was 0.65 microM for platelet lipoxygenase and 0.45 mM for platelet cyclooxygenase. Esculin (the 6-glucoside of esculetin) and umbelliferone (7-hydroxy-coumarin) also selectively inhibited the lipoxygenase, though less strongly (IC50 = 290 and 500 microM, respectively). 4-Hydroxycoumarin and coumarin had no inhibitory effect on either enzyme at concentrations up to 1 mM. The mechanism of the lipoxygenase inhibition by esculetin was non-competitive. Other antioxidants (hydroquinone, gallic acid and ascorbic acid) were less inhibitory to both enzymes and showed little selectivity.

4-Hydroxycoumarins↗
PubMed1982

Protective effect of saikosaponin-d isolated from Bupleurum falcatum L. on CCl4-induced liver injury in the rat.

The effects of saikosaponin-d extracted from the roots of Bupleurum falcatum L. on carbon tetrachloride-induced hepatic injury were studied in rats. Pretreatment with saikosaponin-d produced a remarkable inhibitory action on acute hepatic injury by CCl4. A significant inhibition of lipid peroxidation induced by an acute dose of CCl4 in the liver of rats pre-treated with saikosaponin-d was also noted. Continuous injection of CCl4 caused liver cirrhosis in rats but the severity of cirrhosis was reduced in rats treated simultaneously with CCl4 and saikosaponin-d.

Animals↗
PubMed1982

[Pharmacological studies on a prescription containing Bupleuri Radix (IV). Effects of saikosaponin on the anti-inflammatory action of glucocorticoid].

Effects of saikosaponin d extracted from Bupleuri Radix on the antigranulomatous action of glucocorticoid were investigated in rats by the cotton pellet method. Saikosaponin d (0.1 mg/kg/day x 4 days) and dexamethasone (0.1 mg/kg/day x 4 days) reduced the weight of cotton-induced granuloma to 89.58% and 88.54% of the control, respectively. These antigranulomatous actions failed to show a significant difference from the control. However, the combined administration of saikosaponin d and dexamethasone produced a significant antigranulomatous action, namely, the decrease in the weight of granuloma to 62.5% of the control. While the combination of saikosaponin d and dexamethasone showed an inhibitory trend against the increase in serum triglyceride as induced by dexamethasone, the cholesterol level was elevated by the combination. The body weight was significantly reduced by the combined administration as compared with the group treated with dexamethasone alone, but no apparent difference existed in the adrenal and thymus weights between them.

Animals↗
PubMed1981

Erythrocyte membrane stabilization by plant saponins and sapogenins.

Effects of saponins extracted from Bupleuri Radix (saikosaponin) and the corresponding aglycones on hypotonic or hyperthermic hemolysis were investigated. Low concentrations of saikosaponins protect or stabilize rat erythrocytes against both hypotonic and heat-induced hemolysis. Minor modifications of the aglyconic part of the saikosaponin have enormous effects on the membrane stabilizing potency. Saikogenins also protect erythrocytes from hypotonic hemolysis but do not show any prevention of heat-induced hemolysis. It is suggested that saikogenins react with erythrocyte membranes in a quite different manner from saponins and that the existence of the sugar moiety plays an important role in the reaction with membranes as does a slight modification of the molecular structure in the aglyconic part.

Animals↗