Hajime Fujimura

The anti-ulcer effect in rats of ginger constituents

The effects of ginger, a pungent stomachic natural medicine, on HCl/ethanol-induced gastric lesions in rats, were examined. The orally administered acetone extract at 1000 mg/kg and zingiberene, the main terpenoid from acetone extract, at 100 mg/kg significantly inhibited gastric lesions by 97.5 and 53.6%, respectively. 6-Gingerol, the pungent principle, at 100 mg/kg significantly inhibited gastric lesions by 54.5%. These results suggest that zingiberene, the terpenoid and 6-gingerol are important constituents in stomachic medications containing ginger.

Antianoxic action of evodiamine, an alkaloid in Evodia rutaecarpa fruit

In order to determine the antianoxic potential of evodiamine, its effects were compared to those of vinpocetine (VPT), using a series of animal models of anoxia. In mice, evodiamine was equivalent to VPT in the KCN-induced anoxia model but was greater than VPT in the low-pressure-induced anoxia model. Its effectiveness was increased by combined treatment with physostigmine, suggesting the involvement of a cholinergic mechanism in the antianoxic action of evodiamine.

Anti-ulcer action of Panax japonicus rhizome

Using HCl/ethanol-induced ulcer in rats as a screening model, an anti-ulcer effect was observed for a methanol extract of Panax japonicus rhizome, saponin fractions and chikusetsusaponin III. Results suggest that the gastric mucous membrane-protective effect of the methanol extract is likely to be due to the crude saponin fraction and chikusetsusaponin III.

Effects of alismol isolated from Alismatis Rhizoma on calcium-induced contraction in the rabbit thoracic aorta

We examined the inhibitory effects of alismol, a sesquiterpenoid isolated from Alismatis Rhizoma, on vascular contractions induced by high concentrations of K+ and Ca2+, and on 45Ca2+ retention in normal and in high K+-containing medium. Alismol affected neither the resting tension nor the 45Ca2+ retention in normal medium, but it inhibited sustained contraction and increased 45Ca2+ retention induced by high K+ concentrations. Alismol did not affect norepinephrine-induced contractions in normal medium, nor phasic contractions in Ca2+-free medium. These results suggested that alismol inhibited mainly Ca2+ influx through a voltage-dependent Ca2+ channel.

Antiulcer action of sophora flavescens root and an active constituent. I

The effect of a methanol extract of Sophora flavescens root was examined on gastric ulcers induced in rats by HCl/ethanol in order to substantiate its reputed protective properties. Oral doses of 1 g/kg completely suppressed ulceration. Results suggest that oral administration of 50 mg/kg of vexibinol, a flavanol found in the extract, inhibited ulceration more effectively than spizofurone at 100 mg/kg.

Vascular dilatory action of Artemisia capillaris bud extracts and their active constituent

In perfusion experiments, the acetone extract of Artemisia capillaris buds significantly inhibited the response to norepinephrine of helical strips of rabbit thoracic aorta. The acetone extract was fractionated by column chromatography to identify the active constituent. Kinetic experiments using rabbit thoracic aorta showed that 6,7-dimethoxycoumarin (scoparone) has a marked inhibitory effect on the contractions induced by norepinephrine, 5-hydroxytryptamine, histamine and angiotensin II. Like nitroglycerin, scoparone appeared to be a competitive antagonist of norepinephrine.

Vasodilatory active principles of Sophora flavescens root.

Flavanones vexibinol and kurarinone were isolated from an ethyl acetate extract of Sphora flavescens roots and assayed using isolated rabbit and rat thoracic aorta helical strips. These compounds inhibited KCl and norepinephrine maximum contractions in a concentration-dependent manner in the rat but only KCl contractions in the rabbit. Vexibinol and kurarinone weakly inhibited histamine- and serotonin-induced contractions in the rabbit. The results suggest that these flavanones may inhibit Ca2+ influx through a voltage-dependent Ca2+ channel.

The vasorelaxant effect of evocarpine in isolated aortic strips: mode of action

The effect of evocarpine (EVO), a quinolone alkaloid isolated from Evodiae fructus, on Ca2+-blocking activity has been examined. In the isolated rat thoracic aorta evocarpine significantly inhibited the contraction induced by 60 mM K+ with an IC50 of 9.8 microM, and that induced by external Ca2+ in the depolarized muscle in concentrations of 10-100 microM. The relaxant effect of evocarpine and verapamil was antagonized by Bay K8644. The increase of 45Ca2+-influx induced by 60 mM K+ was significantly inhibited by 100 microM evocarpine. In the isolated rabbit thoracic aorta 100 microM evocarpine had no effect on the norepinephrine-induced contraction in normal medium or on the phasic contraction in Ca2+-free medium or on the transient relaxation induced by activation of the Na+ pump. The content of cyclic AMP or cyclic GMP was unchanged. These results suggest that evocarpine inhibits Ca2+ influx through voltage-dependent calcium channels.

Analgesic and anti-inflammatory activities in rats of α-(3,5-di-t-butyl-4-hydroxybenzylidene)-γ-butyrolactone (KME-4), and its intestinal damage

α‐(3,5‐Di‐t‐butyl‐4‐hydroxybenzylidene)‐γ‐butyrolactone (KME‐4), an anti‐inflammatory drug, possesses analgesic activity in rat models. In the acetic acid‐induced writhing test, the oral ED50 values for KME‐4, indomethacin, naproxen and ibuprofen were 5.2, 3.8,7.0 and 18.6 mg kg−1, respectively, and the relative order of potency of these drugs correlated with their inhibitory effect on acetic acid‐induced vascular permeability in rats. KME‐4 also had analgesic activity in the tests of Randall‐Selitto and adjuvant arthritic flexion, but the dose required was greater than that needed in the writhing test. KME‐4 (10 mg kg−1 day−1 orally) has a preventive effect against adjuvant‐induced arthritis in rats, and its efficacy was more potent than indomethacin (2 mg kg−1 day−1) as judged from various parameters determined. When administered orally to rats once daily for 12 days, KME‐4 caused perforating ulceration of the small intestine but this action was less potent than the effect of indomethacin, naproxen and ibuprofen.