Publications (101) View all
-
Dataset: Aginoside saponin, a potent antifungal compound, and secondary metabolite analyses from Allium nigrum L
-
Article: Corosolic acid impairs tumor development and lung metastasis by inhibiting the immunosuppressive activity of myeloid-derived suppressor cells.
[show abstract] [hide abstract]
ABSTRACT: SCOPE: Recent studies demonstrated that myeloid cells are associated with systemic immunosuppression in tumor-bearing hosts. In particular, myeloid cells positive for Gr-1 and CD11b in tumor-bearing mice are called myeloid-derived suppressor cells (MDSC) because of their suppression of T-cell activation. In this study, we investigated the antitumor effects of corosolic acid (CA) in murine sarcoma model. METHODS AND RESULTS: The results from the in vivo study showed that CA administration did not suppress the tumor proliferation index, but significantly impaired subcutaneous tumor development and lung metastasis. Furthermore, CA administration inhibited signal transducer and activator of transcription-3 (Stat3) activation and increased in the number of infiltrating lymphocytes in tumor tissues. Ex vivo analysis demonstrated that a significant immunosuppressive effect of MDSC in tumor-bearing mice was abrogated and the mRNA expressions of cyclooxygenase-2 and CCL2 in MDSC were significantly decreased by CA administration. Furthermore, CA enhanced the antitumor effects of adriamycin and cisplatin in in vitro. CONCLUSION: Since Stat3 is associated with tumor progression not only in osteosarcoma, but also in other malignant tumors, our findings indicate that CA might be widely useful in anticancer therapy by targeting the immunosuppressive activity of MDSC and through its synergistic effects with anticancer agents.Molecular Nutrition & Food Research 02/2013; · 4.30 Impact Factor -
Article: Aginoside saponin, a potent antifungal compound, and secondary metabolite analyses from Allium nigrum L.
Phytochemistry Letters 01/2013; · 1.22 Impact Factor -
Article: Screening of promising chemotherapeutic candidates from plants against human adult T-cell leukemia/lymphoma (II): apoptosis of antiproliferactive principle (24,25-dihydrowithanolide D) against ATL cell lines and structure-activity relationships with withanolides isolated from solanaceous plants.
[show abstract] [hide abstract]
ABSTRACT: Adult T-cell leukemia/lymphoma (ATL) is an incurable peripheral T-cell malignancy caused by human T-cell lymphotropic virus type I. In our preceding paper, 214 extracts from 162 plants were screened to elucidate the antiproliferative principles against ATL cell lines. Several withanolides were isolated and the structure-activity relationships (SAR) examined. To extend the search for SAR, 31 further withanolides, previously isolated from solanaceous plants, were tested against ATL cell lines. The presence of a 4β-hydroxy group as well as a 5β,6β-epoxy group appeared to be essential for the activity. In contrast, the presence of a sugar moiety at either the 3- or the 27-position led to a reduction in the activity. Furthermore, 24,25-dihydrowithanolide D (13) was identified as the most potent inhibitor, showing selective toxicity against ATL cell lines by inducing apoptotic cell death.Journal of Natural Medicines 09/2012; · 1.39 Impact Factor -
Article: Physiological functions of solanaceous and tomato steroidal glycosides
[show abstract] [hide abstract]
ABSTRACT: Solanaceous plants are widely distributed. They are used as food and in folk medicine. Our studies focused on these plants, starting with Solanum lyratum and S. nigrum, which are used as anti-cancer and anti-herpes agents. Extensive investigations in 45 Solanum plant species revealed that a considerable amount of glycosides such as spirosolane, solanidane, spirostane and furostane is in these plants, and some of the isolated glycosides showed strong anti-proliferative activity against various cancer cell lines and anti-herpes activity. Furthermore, we have discovered a few new hypothetical biosynthetic routes in which the pathways for the biosynthesis of 16-acyl-pregnane and pregnane glycosides were the most interesting. The occurrence of these pregnane compounds indicates that they might be internally biosynthesized in the plant from furostanol glycosides by a reaction that is similar to Marker degradation. Furthermore, this may imply that the administration of steroidal glycosides may result in their metabolization into pregnane derivatives possessing various activities. In order to perform metabolic experiments using the steroidal glycosides, we recently isolated tomato glycosides from ripe tomato fruits for the first time. For this experiment, we examined the metabolites in urine obtained from persons that consumed tomatoes. We obtained androstane derivatives that were probably metabolized via pregnane derivatives from tomato glycoside. Hence, when a steroidal glycoside is administered, it may be metabolized into a type of steroidal hormone with various physiological activities.Journal of Natural Medicines 04/2012; 61(1):1-13. · 1.39 Impact Factor
