Development and validation of UHPLC-ESI-MS/MS bioanalytical method, ADMET profiling, and pharmacokinetic study of bioactive phytoconstituents from Ayurvedic botanical Guduchi (Tinospora cordifolia)

Tinospora cordifolia (TC) is known for its immense therapeutic applications in 'Ayurveda', which has created considerable scientific interest in pharmacology. Thus, a targeted and rapid bioanalytical UHPLC-ESI-MS/MS method was developed and validated for the extraction of its bioactive markers from diverse classes of diterpenes as tinosporide (TC1) and phytosterol-20-β-hydroxyecdysone (TC2) and isoquinoline alkaloids-jatrorrhizine (TC3), tetrahydropalmatine (TC4) from the TC stem extract (TCE) in rat plasma by solid phase extraction technique (SPE). The optimum recovery (≥ 90 %) was achieved for TC1–4 and internal standard fluoxymesterone (IS) with the SPE method on the C18 phase. The analytes were subjected to chromatographic analysis on the Agilent C18 Zorbax Eclipse Plus column (4.6 × 100 mm, 3.5 µ) with a gradient program using 0.1 % acetic acid in water (% v/v) and acetonitrile as mobile phase at a flow rate of 0.500 mL/min. The MS/MS quantification and validation were performed on the Shimadzu 8045 tandem mass spectrometer associated with the heated-ESI probe in SRM mode. The precursor to product ion transitions m/z 416.20→375.10 (TC1), 481.40→445.20 (TC2), 339.15→323.05 (TC3), 356.25→192.10 (TC4) and 337.20→91.00 (IS) were used for quantification. Also, in silico ADMET prediction and in vivo pharmacokinetics revealed that TC1–4 was well absorbed from the GI tract and could act as a P-GP substrate. In the pharmacokinetic study, TC1–4 could be detected by this validated bioanalytical method. The TC1 was found bioavailable, having an optimum half-life of > 9.0 h to exhibit therapeutic activity with other TC bioactive markers in vivo. This research is the first comprehensive study on in silico and in vivo pharmacokinetics of TC biomarkers, which may aid in further pre-clinical and clinical trial investigations.