Tsutomu Nakanishi

Bio: Tsutomu Nakanishi is an academic researcher from Setsunan University. The author has contributed to research in topics: Triterpene & Glycoside. The author has an hindex of 25, co-authored 82 publications receiving 1682 citations. Previous affiliations of Tsutomu Nakanishi include Kyoto Prefectural University of Medicine & Gifu Pharmaceutical University.

Antibacterial Activity of Extracts Prepared from Tropical and Subtropical Plants on Methicillin-Resistant Staphylococcus aureus

Abstract: The antibacterial activity of the extracts prepared from 181 species (75 families) of tropical and subtropical plants was screened against various types of pathogenic bacteria. Among the 505 extracts tested, 53 of them inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA). The active extracts obtained from barks of Shorea hemsleyana and roots of Cyphostemma bainessi were separated to their components, some of which greatly reduced the viable cell number of MRSA. These active compounds were all identified as stilbene derivatives. Hemsleyanol d, one of the stilbene tetramer isolated from S. hemsleyana, was the most effective compound and had MIC of 2 μg/ml.

Isolation and identification of hypotensive principles in red-mold rice

Abstract: During an initial search for pharmacologically active principles in red-mold rice, two hypotensive compounds were isolated and identified. The active principles, A-3 and B-1, were fractionated and purified from the EtOH extract of red-mold rice prepared with Monascus pilosus through extraction with H2O, Amberlite CG-120 column chromatographies and high-performance liquid chromatography on an ODS column. A-3 was identified as acetylcholine chloride by comparison with an authentic sample, and B-1, colorless needles of mp 203-205 °C, was proved to be identical with authentic γ-aminobutyric acid. Intravenously administered A-3 (0.5 μg/kg) and B-1 (250μg/kg) produced potent depression of the carotid arterial blood pressure in spontaneously hypotensive rats, as did the corresponding authentic samples.

Isolation of Apoptosis- and Differentiation-Inducing Substances toward Human Promyelocytic Leukemia HL-60 Cells from Leaves of Juniperus taxifolia

Abstract: A chloroform extract of the leaves of Juniperas taxifolia exhibited a marked antiproliferative effect on human promyelocytic leukemia HL-60 cells at a concentration of 2.5 μg/ml. Deoxypodophyllotoxin (4) was identified in the extract as an outstanding antiproliferative compound, and five diterpenes (1–3, 5, and 6) were isolated as known compounds with weak or no cytotoxicity. These compounds were examined for their respective apoptosis- and differentiation-inducing activities toward HL-60 cells by DNA fragmentation and NBT-reducing assays, respectively. Among them, 7α-hydroxysandaracopimaric acid (6) was found to have a potent differentiation-inducing activity in a dose-dependent manner at 0.125–2 μg/ml (0.39–6.29 μM), together with apoptosis-inducing activity at concentrations of more than 2.5 μg/ml (7.86 μM). Deoxypodophyllotoxin (4) that exerted cytotoxic and apoptosis-inducing activities at 2 ng/ml (5 nM) did not induce differentiation at the same concentration, and the other diterpenes (1–3 and 5) sh...

Pomegranate and its Many Functional Components as Related to Human Health: A Review

Abstract: Pomegranate (Punica granatum L.) is an ancient fruit that is widely consumed as fresh fruit and juice. The use of pomegranate fruit dates from ancient times and reports of its therapeutic qualities have echoed throughout the ages. Both in vitro and in vivo studies have demonstrated how this fruit acts as antioxidant, antidiabetic, and hypolipidemic and shows antibacterial, antiinflammatory, antiviral, and anticarcinogenic activities. The fruit also improves cardiovascular and oral health. These beneficial physiological effects may also have preventive applications in a variety of pathologies. The health benefits of pomegranate have been attributed to its wide range of phytochemicals, which are predominantly polyphenols, including primarily hydrolyzable ellagitannins, anthocyanins, and other polyphenols. The aim of this review was to present an overview of the functional, medical, and physiological properties of this fruit.

Novel therapeutic applications of cardiac glycosides

Abstract: Cardiac glycosides are a diverse family of naturally derived compounds that bind to and inhibit Na+/K+-ATPase. Members of this family have been in clinical use for many years for the treatment of heart failure and atrial arrhythmia, and the mechanism of their positive inotropic effect is well characterized. Exciting recent findings have suggested additional signalling modes of action of Na+/K+-ATPase, implicating cardiac glycosides in the regulation of several important cellular processes and highlighting potential new therapeutic roles for these compounds in various diseases. Perhaps most notably, the increased susceptibility of cancer cells to these compounds supports their potential use as cancer therapies, and the first generation of glycoside-based anticancer drugs are currently in clinical trials.