Akira Inada

Bio: Akira Inada is an academic researcher from Setsunan University. The author has contributed to research in topics: Triterpene & Juniperus communis. The author has an hindex of 21, co-authored 65 publications receiving 1108 citations. Previous affiliations of Akira Inada include Josai University & Indian National Association.

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...

Induction of apoptosis by hinokitiol, a potent iron chelator, in teratocarcinoma F9 cells is mediated through the activation of caspase-3.

Abstract: . Hinokitiol, a potent iron chelator, has been reported to induce differentiation in teratocarcinoma F9 cells with a reduction of viable cells. In this study, we examined the steps leading to eventual cell death by hinokitiol during differentiation. Hinokitiol induced DNA fragmentation of F9 cells in a concentration-and time-dependent manner. This effect was also observed in a cell-free system using the nuclei from intact cells and the cytosols from hinokitiol-treated cells. In contrast, hinokitiol methyl ether and hinokitiol--Fe (III) complex, which are deficient in iron-chelating activity, showed no DNA fragmentation activity in both cell culture and cell-free systems. These results suggest that iron deprivation by hinokitiol may be involved in the induction of apoptosis of F9 cells. Caspase-3, one of the key enzymes in the apoptotic cascade, was specifically activated by hinokitiol treatment, but not by the other two derivatives. In addition, its specific inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, strongly blocked hinokitiol-induced DNA fragmentation. These results indicate that iron deprivation by hinokitiol can induce apoptosis of F9 cells through the activation of caspase-3.

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.

Digoxin and other cardiac glycosides inhibit HIF-1α synthesis and block tumor growth

Abstract: A library of drugs that are in clinical trials or use was screened for inhibitors of hypoxia-inducible factor 1 (HIF-1) Twenty drugs inhibited HIF-1-dependent gene transcription by >88% at a concentration of 04 μM Eleven of these drugs were cardiac glycosides, including digoxin, ouabain, and proscillaridin A, which inhibited HIF-1α protein synthesis and expression of HIF-1 target genes in cancer cells Digoxin administration increased latency and decreased growth of tumor xenografts, whereas treatment of established tumors resulted in growth arrest within one week Enforced expression of HIF-1α by transfection was not inhibited by digoxin, and xenografts derived from these cells were resistant to the anti-tumor effects of digoxin, demonstrating that HIF-1 is a critical target of digoxin for cancer therapy

Plants used in Chinese and Indian traditional medicine for improvement of memory and cognitive function.

Abstract: In traditional practices of Ayurvedic and Chinese medicine, numerous plants have been used to treat cognitive disorders, including neurodegenerative diseases such as Alzheimer's disease (AD). An ethnopharmacological approach has provided leads to identifying potential new drugs from plant sources, including those for cognitive disorders. Many drugs currently available in Western medicine were originally isolated from plants, or are derived from templates of compounds isolated from plants. Some anticholinesterase (anti-ChE) alkaloids isolated from plants have been investigated for their potential in the treatment of AD, and are now in clinical use. Galantamine, isolated from several plants including Lycoris radiata Herb., which was used in traditional Chinese medicine (TCM), is licensed in the United Kingdom for the treatment of mild to moderate AD. Various other plant species have shown pharmacological activities relevant to the treatment of cognitive disorders, indicating potential for therapeutic use in disorders such as AD. This article reviews some of the plants and their active constituents that have been used in traditional Ayurvedic medicine and TCM for their reputed cognitive-enhancing or antiageing effects. Plants and their constituents with pharmacological activities that may be relevant for the treatment of cognitive disorders, including enhancement of cholinergic function in the central nervous system (CNS), anti-inflammatory and antioxidant activities, are discussed.