Biomedical subjects

Kazuhisa Matsunaga

Publications and source records attributed to Kazuhisa Matsunaga.

7 recordsLinked to original sources

PubMed2006

Antiproliferative constituents from umbelliferae plants. IX. New triterpenoid glycosides from the fruits of Bupleurum rotundifolium.

The MeOH extract of the fruits of Bupleurum rotundifolium showed inhibitory activity against human gastric adenocarcinoma (MK-1) cell growth. Bioactivity-guided fractionation of the MeOH extract led to the isolation of four new triglycosides of 13beta,28-epoxy oleanane-type triterpenes, named rotundiosides O, Q, S and T; 12 new glycosides of oleanane-type triterpenes, named rotundiosides J-N, P, R, U-Y, and others; echinocystic acid 3-O-sulfate; and three known oleanane-type triterpene glycosides, rotundiosides A, F and G. The structures of the new isolates were determined based on chemical and spectroscopic evidence. The GI(50) of isolates against MK-1, HeLa and B16F10 cell lines are reported.

Antineoplastic Agents, Phytogenic↗

PubMed2005

Technetium labeling of dextran incorporating cysteamine as a ligand.

INTRODUCTION: Technetium-99m-labeled dextran is a useful imaging agent for procedures such as angiocardiography and lymphoscintigraphy. To improve the availability of 99mTc-labeled dextran, we designed a cysteamine ligand system for dextran labeling. METHODS: Cysteamine derivatized dextran was synthesized as follows. Dextran was oxidized with sodium periodate, coupled with cysteamine and reduced with sodium borohydride to provide the desired amine ligand. The cysteamine-dextran conjugate was then labeled with reduced 99mTc. Whole-body scintigraphy and biodistribution were examined following injection of the 99mTc-labeled cysteamine-conjugated dextran (99mTc-cysteamine-dextran) in ICR mice. Lymphoscintigraphy was performed after intradermal injection of 99mTc-cysteamine-dextran in SD rats. RESULTS: The cysteamine-derived dextran was easily labeled with reduced 99mTc in greater than 96% yield. 99mTc-cysteamine-dextran has a higher chelation stability against diethylenetriamine pentaacetic acid (DTPA) than the 99mTc-dextran. Axillary lymph nodes were clearly visible after intradermal injection of 99mTc-cysteamine-dextran in rats. CONCLUSION: These results suggest that 99mTc-cysteamine-dextran is available for lymphoscintigraphy. This methodology could expand the usage of 99mTc-labeled dextran, particularly for diagnostic purposes.

Animals↗

PubMed2005

Antiproliferative constituents from Umbelliferae plants VII. Active triterpenes and rosmarinic acid from Centella asiatica.

The antiproliferative constituents in the MeOH extract from the aerial parts of Centella asiatica were investigated. Activity-guided fractionation of MeOH extract resulted in the isolation of ursolic acid lactone, ursolic acid, pomolic acid, 2alpha,3alpha-dihydroxyurs-12-en-28-oic acid, 3-epimaslinic acid, asiatic acid, corosolic acid, and rosmarinic acid. Antiproliferative activity of the isolated compounds against human gastric adenocarcinoma (MK-1), human uterine carcinoma (HeLa), and murine melanoma (B16F10) cells was estimated.

Apiaceae↗

PubMed2003

Vitamin E isoforms alpha-tocotrienol and gamma-tocopherol prevent cerebral infarction in mice.

Alpha-tocopherol and its derivatives have been shown to be effective in reducing cerebral ischemia-induced brain damage. However, the effects of other vitamin E isoforms have not been characterized. In the present study, we investigated the effects of six different isoforms of vitamin E on the ischemic brain damage in the mice middle cerebral artery (MCA) occlusion model. All vitamin E isoforms were injected i.v., twice, immediately before and 3 h after the occlusion. Alpha-tocopherol (2 mM), alpha-tocotrienol (0.2 and 2 mM) and gamma-tocopherol (0.2 and 2 mM) significantly decreased the size of the cerebral infarcts 1 day after the MCA occlusion, while gamma-tocotrienol, delta-tocopherol and delta-tocotrienol showed no effect on the cerebral infarcts. These results suggest that alpha-tocotrienol and gamma-tocopherol are potent and effective agents for preventing cerebral infarction induced by MCA occlusion.

Animals↗

PubMed2003

The behavior of dihydropyrazine with DNA strand-breakage activity in vivo.

The effects on the viability of cell lines treated with 2,3-dihydro-5,6-dimethylpyrazine and its derivatives, which revealed DNA strand-breakage activity by the generation of radicals in vitro, were recognized from certain morphological changes and the detection of apoptosis-related proteins: cleaved PARP and SAPK/JNK. These results would suggest that sugar-derived dihydropyrazines induce changes in the cells of certain organs and cause various internal injuries in vivo. The biodistribution of 14C-labelled 2,3-dihydro-5,6-dimethylpyrazine was studied in mouse and the autoradiograms showed highly contrasting results. Radioactivity was high in the brain, spinal cord, salivary gland, and thymus and low in the heart, stomach, and blood. The result was supported by the activity (% dose per organ).

Animals↗

PubMed2002

Delivery systems for antioxidant nutrients.

The novel role of oxidants and antioxidants as part of cell signaling cascades has opened new areas of research in several disease states and their therapeutic strategies. For successful therapeutic manipulation of reactive oxygen species (ROS)-mediated cellular signaling pathways, it would necessitate control of the critical balance of oxidants/antioxidants in the target site by the antioxidant. Another way of controlling the critical balance is to avoid excessive generation of ROS from nutrients and/or drugs. From the viewpoint of controlling the balance between the oxidant and antioxidant status, this review focuses on the prodrug approach for delivery systems of vitamin E, a major antioxidant nutrient in the membrane, and on the reductive activation-independent delivery system of vitamin K hydroquinone by a prodrug approach, which can avoid excessive generation of ROS synchronized with the activation process of vitamin K.

Animals↗

PubMed2002

Novel d-gamma-tocopherol derivative as a prodrug for d-gamma-tocopherol and a two-step prodrug for S-gamma-CEHC.

d-gamma-Tocopherol (gamma-Toc) and its major metabolite, 2, 7, 8-trimethyl-2S-(beta-carboxyethyl)-6-hydroxychroman (S-gamma-CEHC), are currently receiving attention concerning their unique pharmacological activities. In order to achieve the efficient delivery of gamma-Toc and S-gamma-CEHC in vivo, we synthesized d-gamma-tocopheryl N,N-dimethylglycinate hydrochloride (gamma-TDMG) as a water-soluble prodrug of gamma-Toc and a two-step prodrug of S-gamma-CEHC. gamma-TDMG is a solid (mp 161-163 degrees C) and is quite soluble in water over 50 mM. The hydrolysis of gamma-TDMG was effectively catalyzed by esterases in rat and human liver microsomes. The disposition of gamma-TDMG after iv administration in rats was compared with that of gamma-Toc solubilized with the surfactant, polyoxyethylene hydrogenated castor oil. The plasma and liver levels of gamma-Toc rapidly increased after the iv administration of the gamma-TDMG. The liver availability of gamma-Toc after the administration of gamma-TDMG was two times higher than that of the gamma-Toc administration. The relative systemic availability of S-gamma-CEHC after the gamma-TDMG administration was an equivalent value (102%), and the mean residence time of S-gamma-CEHC was eight times longer than the racemic gamma-CEHC administration. Based on these results, gamma-TDMG was identified as the most promising water-soluble prodrug of gamma-Toc and the two-step prodrug of S-gamma-CEHC.

Animals↗