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Biomedical subjects

Hisae Oku

Publications and source records attributed to Hisae Oku.

7 recordsLinked to original sources

Antipruritic effects of the fruits of Chaenomeles sinensis.

A 35% EtOH extract of the fruits of Chaenomeles sinensis, long utilized as a folk medicine for cough, significantly inhibited the pruritogenic agent compound 48/80 (COM)-induced scratching behavior in mice. Antipruritic activity-guided fractionation and purification yielded active quercetin, apigenin, and catechin derivatives, which exhibited significant inhibitory effects on COM-induced scratching behavior. To the best of our knowledge, apigenin (5), apigenin 7-glucronide (6), and apigenin 4'-methoxy-7-glucronide (acacetin 7-glucronide) (7) were isolated from the fruits of C. sinensis for the first time. The active fraction and these compounds also inhibited serotonin-, platelet activating factor-, and prostaglandin E(2)-induced scratching behavior, but did not inhibit histamine-induced scratching behavior or locomotive behavior. This study also showed that the fruits of C. sinensis could be used to treat allergic itching sensation.

Animals↗

Bisxanthones from Hypericum japonicum: inhibitors of PAF-induced hypotension.

The CHCl3-soluble part (HJ) of the MeOH extract from Hypericum japonicum afforded new bisxanthones, jacarelhyperols A (1) and B (2). The structures were elucidated by spectral methods. These compounds and HJ showed significant inhibitory effects against PAF-induced hypotension by an in vivo evaluation method, which can reveal the pharmacological action of the test material.

Animals↗

Antipruritic effects of 1,4-naphthoquinones and related compounds.

The antipruritic effects of orally administered 1,4-naphthoquinone derivatives and related compounds on compound 48/80-induced scratching behavior in mice were studied. 2-Hydroxy-3-(2-hydroxyethyl)-1,4-naphthoquinone, ferulic acid, 2,2'-methylenebis(3-hydroxy-1,4-naphthoquinone), and 2,2'-ethylidenebis(3-hydroxy-1,4-naphthoquinone) (impatienol) all exhibited significant antipruritic activity. However, 2-methoxy-3-(2-hydroxyethyl)-1,4-naphthoquinone (balsaquinone), which was isolated from a natural source for the first time, did not show any activity. The present results indicate that these compounds are promising for treating allergic diseases with chronic and severe pruritus.

Animals↗

Anti-inflammatory and anti-allergic activities of hydroxylamine and related compounds.

The anti-inflammatory activities of several novel oximes and O-acyl oximes that we synthesized have been reported based on carrageenan-induced rat foot-pad swelling assay and histamine-induced rat vascular permeability assay. A cyclooxygenase (COX)-1 inhibitory effect has also been reported for 4'-piperidinoacetophenone and 4'-morpholinoacetophenone oximes and their O-acyl derivatives. To further search for more effective non-steroidal anti-inflammatory or anti-allergic drugs, 1-hydroxylamino-1-(4'-piperidinophenyl) ethane (P-HA) and 1-hydroxylamino-1-(4'-morpholinophenyl) ethane (M-HA) were synthesized from the corresponding oximes with sodium cyanoborohydride, and N,O-diacetyl hydroxylamines (P-HA-Ac and M-HA-Ac) were prepared from these hydroxylamines using acetyl chloride. These hydroxylamines and N,O-diacetyl hydroxylamines clearly exhibited inhibitory effects on mouse carrageenan-induced foot-pad swelling induced by oral administration (150, 37.5 mg/kg). An oral dose of P-HA-Ac (150 mg/kg) significantly inhibited the mouse anaphylactic reaction to ovalbumin measured by the abdominal wall (AW) method. Percutaneous administration of P-HA and M-HA significantly inhibited 2,4-dinitrofluorobenzene (DNFB)-induced contact hypersensitivity reaction (type IV) in mice at a dose of 0.5 and 0.1 mg/ear, respectively. All tested hydroxylamines and N,O-diacetyl hydroxylamines clearly inhibited both COX-1 and COX-2 enzyme activities with IC(50) values of 1.9-28.7 and 1.6-2.9 micro M against COX-1 and COX-2, respectively. Hydroxylamines (P-HA and M-HA) also showed a 5-lipoxygenase inhibitory effect.

Animals↗

Effects of conjugated linoleic acid on anaphylaxis and allergic pruritus.

The effects of conjugated linoleic acid (CLA) against anaphylaxis and allergic pruritus were investigated using a in vivo assay. Inhibitory effects of CLA were observed on the immediate (type 1) hypersensitivity reaction, with CLA significantly suppressing the decrease in blood pressure (BP) and blood flow (BF) induced by the hen egg-white lysozyme (HEL)-anaphylactic reaction in ddY mice. After oral administration, CLA showed antipruritic activity, with significant inhibition of scratching behavior induced by compound 48/80 (COM), a histamine-release agent. When painted onto the skin, CLA also inhibited COM, platelet-activating factor, and protease-induced scratching behavior, and COM-induced vasodilation of the skin. CLA offers promise as a drug for the treatment of allergic and inflammatory pruritus not only as an oral but also a topical agent. The present findings demonstrate that CLA can be effective for the prevention and treatment of allergic disease with severe pruritus.

Anaphylaxis↗

Preventive effects of Impatiens balsamina on the hen egg-white lysozyme (HEL)-induced decrease in blood flow.

Monitoring the blood flow of unanesthesized mice was found to be a reliable and effective method for studying their anaphylactic responses, in addition to the known method of monitoring blood pressure. Hen egg-white lysozyme (HEL)-specific anaphylaxis in mice was estimated by monitoring the decrease in blood flow with a Doppler blood flow meter. This method is convenient for searching for both anaphylaxis and anti-anaphylactic substances from natural products. Using this system, we estimated the anti-anaphylactic effects of the 35% ethanol extract (IB) of petals of Impatiens balsamina L., as well as those of anti-allergic agents currently used. Kaempferol 3-rutinoside and lawsone from IB significantly inhibited the decrease of blood flow. We also found that platelet-activating factor (PAF) and serotonin participate in decreasing the blood flow, but histamine does not.

Anaphylaxis↗

Cyclooxygenase-2 inhibitory 1,4-naphthoquinones from Impatiens balsamina L.

Significant selective cyclooxygenase-2 (COX-2) inhibitory activities were observed for two new 1,4-naphthoquinone sodium salts, sodium 3-hydroxide-2[[sodium 3-hydroxide-1,4-dioxo(2-naphthyl)]ethyl]naphthalene-1,4-dione (impatienolate) (1) and sodium 2-hydroxide-3-(2-hydroxyethyl)naphthalene-1,4-dione (balsaminolate) (2), which were isolated from the corolla of Impatiens balsamina L. (Balsaminaceae). Their structures were elucidated by spectral techniques. Our results offer evidence supporting the use of I. balsamina L. to treat articular rheumatism, pain, and swelling.

Cyclooxygenase 1↗