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Biomedical subjects

Noriko Hirata

Publications and source records attributed to Noriko Hirata.

6 recordsLinked to original sources

Melanogenesis stimulation in murine B16 melanoma cells by Kava (Piper methysticum) rhizome extract and kavalactones.

Melanogenesis stimulation activity of aqueous ethanolic extracts obtained from several different parts of five Piper species, namely Piper longum, P. kadsura, P. methysticum, P. betle, and P. cubeba, were examined by using cultured murine B16 melanoma cells. Among them, the extract of P. methysticum rhizome (Kava) showed potent stimulatory effect on melanogenesis as well as P. nigrum leaf extract. Activity-guided fractionation of Kava extract led to the isolation of two active kavalactones, yangonin (2) and 7,8-epoxyyangonin (5), along with three inactive kavalactones, 5,6-dehydrokawain (1), (+)-kawain (3) and (+)-methysticin (4), and a glucosylsterol, daucosterin (6). 7,8-Epoxyyangonin (5) showed a significant stimulatory effect on melanogenesis in B16 melanoma cells. Yangonin (2) exhibited a weak melanogenesis stimulation activity.

Cell Proliferation↗

Melanogenesis stimulation in murine b16 melanoma cells by umberiferae plant extracts and their coumarin constituents.

Melanogenesis stimulation activities of seven ethanolic extracts obtained from Umbelliferae plants used as Chinese crude drugs, namely the roots of Angelica dahurica BENTH. et HOOK., A. biserrata SHEN et YUAN, Notopterygium incisum TING, Heracleum lanatum MICHX., and H. candicans WALL., and the fruits of Cinidium monnieri (L.) CUSSON and C. formosanum YABE, were examined by using cultured murine B16 melanoma cells. Among them, the extract (5, 25 microg/ml) of H. lanatum showed a potent stimulatory effect on melanogenesis with significant enhancement of cell proliferation in a dose-dependent manner. The melanogenesis stimulatory effects of sixteen coumarins (1-16) isolated from the seven Umbelliferae crude drugs were also examined. Among them, linear-furocoumarins [psoralen (1), xanthotoxin (2), bergapten (3), and isopimpinellin (4)] and angular-furocoumarin [sphondin (13)] exhibited potent melanogenesis stimulation activity. From the view point of structure-activity relationships, it may be assumed that a linear-furocoumarin ring having a hydrogen and/or methoxyl group at 5 and 8 positions such as 1, 2, 3 and 4 was preferable for the melanogenesis stimulation activity. The introduction of a prenyl group into the furocoumarin ring was disadvantageous. Coumarin derivatives having a simple coumarin ring were inactive.

Animals↗

Melanogenesis stimulation in murine B16 melanoma cells by Piper nigrum leaf extract and its lignan constituents.

A methanolic extract from the leaves of Piper nigrum L. showed a significant stimulatory effect on melanogenesis in cultured murine B16 melanoma cells. Activity-guided fractionation of the methanolic extract led to the isolation of two known lignans, (-)-cubebin (1) and (-)-3,4-dimethoxy-3,4-desmethylenedioxycubebin (2), together with a new lignan, (-)-3-desmethoxycubebinin (3). Among these lignans, 1 and 2 showed a significant stimulatory activity of melanogenesis without any significant effects on cell proliferation.

Animals↗

Immusorba TR and PH.

Immusorba TR (IM-TR) and PH (IM-PH) were developed as adsorbents with non-biological materials as affinity ligands to remove pathogenic autoantibodies. The adsorbents of IM-TR and IM-PH are polyvinyl alcohol gel immobilized with tryptophan and phenylalanine as ligand, respectively. IM-TR is clinically applied for treatment of autoimmune neurological diseases such as myasthenia gravis and Guillain-Barre syndrome. IM-PH is used for not only neurological diseases such as GBS and multiple sclerosis but also collagen diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). As many autoantibodies with different specificities have been found to have similar affinities to the ligand of Immusorba, it is expected that Immusorba will be applied to more diseases and contribute to the clarification of the mechanisms of the development of diseases by the identification of adsorbed unknown pathogenic substances with Immusorba.

Absorption↗

Plasma separator Plasmaflo OP.

In recent years, polyethylene and polysulfone membranes have been used for plasma separation in Japan. The polyethylene membrane, manufactured by melt spinning method, has a sponge-like symmetric structure. The plasma separator Plasmaflo OP (Asahi Medical, Tokyo, Japan) with a polyethylene membrane shows excellent performance and safety for plasma separation. More than 20 indications for therapeutic plasmapheresis are reimbursed in Japan. Future development is expected in new membrane designs for new indications or advanced plasmapheresis methodologies.

Biocompatible Materials↗