It is important in the evolution of Oriental medicine that the basic research results of Kampo medicines are returned to clinical cure. Recently, we established some novel assay methods using both cell biology and molecular biology to screen Kampo medicines for the prevention of cancer relapses or to assess the safety of these medicines to treat menopausal symptoms. Our basic studies using these methods brought about some new findings, as follows: (1) maoto suppresses cancer metastasis through inhibition of cancer cell motility, and (2) the medicines used to treat menopausal symptoms have estrogen-like activities and bind directly to estrogen receptors. These studies are the first steps toward applying basic research findings about Kampo medicines to clinical cure. Further basic studies are needed to examine the use of maoto for patients with cancer or to propose the safety of the medicines used to treat menopausal symptoms. We are now preparing some new ex vivo or in vivo assays in view of the clinical application of Kampo medicines.
We recently discovered that MeOH extract from Brassica oleracea var. acephala (kale) (BO) promotes adipocyte differentiation in vitro. Furthermore, we discovered that the CHCl 3 fraction, in particular, promotes adipocyte differentiation in vitro and acts as an insulin sensitizer in vivo. BO is widely taken as juice in Japan because of its vitamins and functional compounds that are beneficial to health and wellness. However, there are no studies evaluating the antihyperglycemic activity of BO in the literature. We examined the effect of the CHCl 3 fraction on plasma glucose concentrations in obese hyperglycemic db/db mice. The CHCl 3 fraction reduced hyperglycemia in mouse models of type 2 diabetes and acted as an insulin sensitizer, as indicated by the lowered plasma glucose concentration after chronic oral administration of the CHCl 3 fraction. This fraction and thiazoridinedione antidiabetic agents, such as ciglitazone, share many biological activities: induction of adipocyte differentiation in vitro, and reduction of hyperglycemia in animal models of type 2 diabetes. This finding demonstrates that BO may contain insulin-sensitizing constituents and could lead to the discovery of novel candidates for a new type of insulin-sensitizing drug.
In Ayurvedic Medicine, some crude drugs and sugar are mixed and fermented, and developed into a herbal liquor called "Asava". During the alcoholic fermentation, the constituents of the crude drug would change chemically. There would thus be a chemical difference between Asava and tincture prepared by soaking the crude drug in alcohol. To investigate the differences between Asava and tincture, we attempted to prepare Asava in our laboratory with ginger rhizomes or jujube fruits and compared the volatile compounds of Asava with those of tincture by GC - MS. The alcohol contents of Ginger Asava and Jujube Asava prepared in the laboratory were 11 % and 9.0 %, respectively, and were almost the same as Asavas obtained in Sri Lanka. A characteristic difference between the Asava and the tincture was the relative content of phenylethanol (Asava: > 30 %, tincture: < 2 %), which is known to be a metabolite of phenylalanine during alcoholic fermentation. In the Ginger Asava, only trace aldehydes such as geranial and neral were found, whereas they were abundant in ginger tincture. Geranial and neral seemed to be reduced to geraniol and nerol. In Jujube Asava, we detected benzyl alcohol that was not detected in jujube tincture. Benzyl alcohol is an aglycon of zizybeoside I or II that was a component of jujube. Therefore, it seemed that glycosides are hydrolyzed by alcoholic fermentation. Hydrolysis of glycosides might help absorption of effective aglycones for the aged.
The Japanese Pharmacopoeia Fifteenth Edition prescribes Akebiae Caulis, Mokutsu in Japanese, should be the woody stem of Akebia quinata Decaisne and A. trifoliata Koidzumi of the family Lardizabalaceae. We examined morphologically the woody stems of 3 wild Akebia taxa growing in Japan, A. quinata, A. trifoliata, and A. × pentaphylla Makino, for the purpose of finding morphological criteria to discriminate them and for identifying Mokutsu in the market. We found that the 3 taxa could be distinguished by a combination of surface color of stem, inner morphologies of stone cells and sclerenchyma cells, etc. with an accuracy of more than 90%, though it had been reported that A. quinata and A. trifoliata could not be distinguished by only stem anatomy. Using these criteria, we found that the woody stems of all 3 Akebia taxa were circulated equally in the Japanese market. This is the first record that the stem of A. × pentaphylla is circulating in the market as Mokutsu.
Cistanche salsa (C.A. Meyer) is a parasitic plant that is used as an oriental medicinal tonic in Japan. In this study we show that the C. salsa extract dialysate (CSD), which was prepared by removing the low-molecular-weight constituents from the extract using a 3,500 Da molecular-weight-cut-off dialysis membrane, enhanced IgM production in the human B cell line BALL-1. At 100 μg/ml, CSD was shown to be able to increase IgM production 1.8-fold with the added effect of slightly inducing cell proliferation. Intracellular IgM production was also increased upon treatment with CSD. These results suggest that the high-molecular-weight constituents in C. salsa is able to activate BALL-1 extracellularly and enhance IgM production.