Determination of cucumarioside A2-2 in mouse spleen by radiospectroscopy, MALDI-MS and MALDI-IMS

The distribution of triterpene glycoside cucumarioside A(2)-2, the main compound of medical lead Cumaside in immunodeficiency diseases, in mouse spleen was determined. For this purpose the stability and dynamics of glycoside content changes over time in Balb/c mouse spleen tissue homogenate as well as the study of the cucumarioside A(2)-2 spatial distribution in tissue sections were investigated using radio-spectroscopy, MALDI-MS and MALDI Imaging Mass Spectrometry (IMS), correspondingly. Cucumarioside A(2)-2 is reliably detected by MALDI-MS in the mouse spleen tissue after single intraperitoneal (i.p.) injection at a dosage of 5 mg/kg. The glycoside is stable in the spleen and does not undergo metabolic transformation in either tissue homogenates or in the intact organ within 24 h after i.p. injection. The cucumarioside A(2)-2 was absorbed fairly rapidly: the glycoside maximum concentration (C-max) in tissue homogenate was observed in the first 30 min after injection; the minimum values were registered in 3 h. These results are in agreement with those obtained in the pharmacokinetic study of H-3-cucumarioside A(2)-2. It was established by MALDI-IMS that glycoside was mainly located in the tunica serosa part of the spleen and only a small amount was detected within the red and white pulp of the organ. MALDI MS images obtained 15-30 min post dosage clearly reflect high drug concentrations in the regions surrounding the organ followed by its decline in the surface part and a very slight redistribution to the internal part of the spleen. (C) 2013 Elsevier B.V. All rights reserved.