Detection of lithospermate B in rat plasma at the nanogram level by LC/MS in multi reaction monitoring mode

Abstract

Low bioavailability and high binding affinity to plasma proteins led to the difficulty for the quantitative detection of lithospermate B (LSB) in plasma. This study aimed to develop a protocol for detecting LSB in plasma. A method was employed to quantitatively detect LSB of 5-500 ng/mL by LC/MS spectrometry in multi reaction monitoring mode via monitoring two major fragments with m/z values of 519 and 321 in the MS2 spectrum. To set up an adequate extraction solution to release LSB captured by plasma proteins, recovery yields of LSB extracted from rat plasma acidified by formic acid or HCl in the presence or absence of EDTA and caffeic acid were detected and compared using the above quantitative method. High recovery yield (∼90%) was achieved when LSB (5-500 ng/mL) mixed in rat plasma was acidified by HCl (5 M) in the presence of EDTA (0.5 M) and caffeic acid (400 μg/mL). The lower limit of detection and the lower limit of quantification for LSB in the spiked plasma were calculated to be 1.8 and 5.4 ng/mL, respectively. Good accuracy (within ±10%) and precision (less than 10%) of intra- and inter-day quality controlled samples were observed. Oral bioavailability of LSB in rat model was detected via this optimized extraction method, and the maximum plasma concentration (C) was found to be 1034.3 ± 510.5 μg/L at t around 10 min, and the area under the plasma concentration-time curve (AUC) was 1414.1 ± 851.2 μg·h/L.

Therapeutic Effects of Lithospermate B Complexed with Mg2+ or Zn2+ on Metabolic Syndrome Induced in Rats Fed with High-Fat Diet

“…Thus, the LSB backbone of the ZLB and MLB is assumed to be the central player for protecting from metabolic syndrome. Because of the low bioavailability of LSB [24,[39][40][41], its effect alone against metabolic syndrome was not investigated in this study. Alternatively, the beneficial effects of ZLB and MLB may come from the increase of their bioavailability.…”

“…Identification of magnesium lithospermate B (MLB) and zinc lithospermate B (ZLB) by HPLC and LC−MS. Lithospermate B (LSB), MLB, and ZLB were detected by HPLC spectrum at 280 nm and confirmed by mass spectrometric analyses on the basis of fragmentation patterns of LSB published previously[24,25].…”

“…To confirm the success of incorporation, LSB, MLB, and ZLB were subjected to HPLC/UV and MS analyses (Figure 1). LSB and MLB were identified by comparing with the HPLC/UV profiles and MS data published previously [24,25]. ZLB was identified by comparing its fragmentation pattern, m/z 780 → 736 (673 − 2 + 65) with the MLB fragmentation pattern, m/z 739 → 695 (673 − 2 + 24).…”

Development of Indirect Competitive ELISA for Lithospermic Acid B of Salvia miltiorrhiza with Its Specific Antibodies Generated via Artificial Oil Bodies

“…Without any manufacturing processes, Danshen, the original dry root of Salvia miltiorrhiza can be basically identified by observing its tissue section; however, the quality of this Chinese herb as well as its manufactory products requires further examination of the chemical contents. Several methods have been developed to evaluate the quality of Danshen, and the most reliable one is to examine its chemical contents extracted with water or organic solvent by HPLC/MS/MS [24,25]. This method provides precise detection for the content of each compound in the crude extract of Danshen resolved on the HPLC system.…”