Isotoosendanin

Isotoosendanin exerts inhibition on triple-negative breast cancer through abrogating TGF-beta-induced epithelial-mesenchymal transition via directly targeting TGFbetaR1.[Pubmed:37521871]

Acta Pharm Sin B. 2023 Jul;13(7):2990-3007.

As the most aggressive breast cancer, triple-negative breast cancer (TNBC) is still incurable and very prone to metastasis. The transform growth factor beta (TGF-beta)-induced epithelial-mesenchymal transition (EMT) is crucially involved in the growth and metastasis of TNBC. This study reported that a natural compound Isotoosendanin (ITSN) reduced TNBC metastasis by inhibiting TGF-beta-induced EMT and the formation of invadopodia. ITSN can directly interact with TGF-beta receptor type-1 (TGFbetaR1) and abrogated the kinase activity of TGFbetaR1, thereby blocking the TGF-beta-initiated downstream signaling pathway. Moreover, the ITSN-provided inhibition on metastasis obviously disappeared in TGFbetaR1-overexpressed TNBC cells in vitro as well as in mice bearing TNBC cells overexpressed TGFbetaR1. Furthermore, Lys232 and Asp351 residues in the kinase domain of TGFbetaR1 were found to be crucial for the interaction of ITSN with TGFbetaR1. Additionally, ITSN also improved the inhibitory efficacy of programmed cell death 1 ligand 1 (PD-L1) antibody for TNBC in vivo via inhibiting the TGF-beta-mediated EMT in the tumor microenvironment. Our findings not only highlight the key role of TGFbetaR1 in TNBC metastasis, but also provide a leading compound targeting TGFbetaR1 for the treatment of TNBC metastasis. Moreover, this study also points out a potential strategy for TNBC treatment by using the combined application of anti-PD-L1 with a TGFbetaR1 inhibitor.

Toosendanin and isotoosendanin suppress triple-negative breast cancer growth via inducing necrosis, apoptosis and autophagy.[Pubmed:34742683]

Chem Biol Interact. 2022 Jan 5;351:109739.

Toosendanin (TSN) and Isotoosendanin (ITSN) are two natural triterpenoids isolated from Fructus Meliae Toosendan or Cortex Meliae. This study aims to observe the inhibition of TSN and ITSN on the growth of triple-negative breast cancer (TNBC) and the preliminary engaged mechanism. Cell viability assay showed that both TSN and ITSN had obvious cytotoxicity in a variety of tumor cells, and they had the best inhibitory effect on TNBC cells including MDA-MB-231, BT549 and 4T1. Propidium iodide (PI) staining results showed the increased number of necrotic MDA-MB-231 and 4T1 cells induced by TSN (20 nM) and ITSN (2.5 muM). Annexin V-FITC and PI double-staining results showed that TSN (20 nM) and ITSN (2.5 muM) induced cell apoptosis in both MDA-MB-231 and 4T1 cells. Moreover, TSN (20 nM) and ITSN (2.5 muM) induced the cleavage of pro-caspase-3 and pro-caspase-9, and decreased the expression of anti-apoptotic Bcl-xL in both MDA-MB-231 and 4T1 cells. Results from scanning electron microscope observation and detecting the expression of microtubule-associated protein 1 light chain 3B (LC3B) and Beclin 1 evidenced that TSN (20 nM) and ITSN (2.5 muM) induced autophagy in both MDA-MB-231 and 4T1 cells. TSN and ITSN decreased 4T1 xenograft tumor growth without inflicting toxicity on vital organs in mice. Collectively, this study shows that natural compound TSN and ITSN suppress TNBC growth via inducing necrosis, apoptosis and autophagy. TSN and ITSN could be promising drugs for TNBC treatment.

Determination of isotoosendanin in rat plasma by liquid chromatography-tandem mass spectrometry: application to pharmacokinetics study.[Pubmed:22815211]

J Chromatogr Sci. 2013 Jan;51(1):82-6.

A rapid, sensitive and accurate liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed and validated for the quantification of Isotoosendanin, an important bioactive component isolated from Meliae cortex. A Capcell PAK C18 column (100 x 4.6 mm) was used for the chromatographic elution using methanol-10 mM ammonium acetate-formic acid (80:20:0.1, v/v/v) as mobile phase at the flow rate of 0.6 mL/min. MS-MS analysis was performed on a triple quadrupole mass spectrometer equipped with an atmospheric pressure chemical ionization source in positive ion mode. Extraction of Isotoosendanin and genistein (internal standard, IS) from rat plasma was determined by precipitating protein treatment. Quantification was performed by MS in the multiple reaction monitoring mode with positive ionization at m/z 557 --> 437 for the analyte and m/z 271 --> 215 for IS, respectively. Linear Isotoosendanin calibration curves were obtained between 2.0-2,000 ng/mL with a correlation coefficient greater than 0.99. Acceptable precision and accuracy were acquired for concentrations over the standard curve range. Satisfactory results were achieved for sensitivity, specificity, recovery, freeze/thaw and stability. This analytical method was successfully applied to determine the pharmacokinetic parameters of Isotoosendanin after an oral administration of 200 mg/kg to rats.

Anti-inflammatory and analgesic activities of ethanolic extract and two limonoids from Melia toosendan fruit.[Pubmed:18384989]

J Ethnopharmacol. 2008 May 22;117(3):463-6.

AIM OF STUDY: The fruit of Melia toosendan Sieb. et Zucc. (MTF) is a traditional Chinese herbal medicine in the treatment of stomachache and many acute or chronic inflammations, as well as ascariasis. This paper aimed to investigate the anti-inflammatory and analgesic activities of the MTF extract and two main limonoid-type triterpenoids isolated from MTF. MATERIALS AND METHODS: The ethanolic extract of MTF and two limonoids, Isotoosendanin (1) and 1-O-tigloyl-1-O-debenzoylohchinal (2) were evaluated for their anti-inflammatory and analgesic activities. Acetic acid-induced vascular permeability and lambda-carrageenan-induced hind paw edema tests in mice were used to investigate anti-inflammatory activity; and acetic acid-induced writhing and hot-plate tests in mice were used to determine analgesic effect. RESULTS: Both the ethanolic extract and two limonoids displayed significant anti-inflammatory effects. Although the ethanolic extract showed remarkable analgesic effects in both writhing and hot-plate tests, the two limonoids had analgesic effects just in writhing test. CONCLUSION: The results suggested that the ethanolic extract of MTF had obvious anti-inflammatory and analgesic activities, and the two limonoids were the active constituents contributing to the anti-inflammatory and analgesic effects of MTF.