Quantitative determination of four immunosuppressants by high resolution mass spectrometry (HRMS)

Protective effect of oligosaccharides isolated from Panax ginseng C. A. Meyer against UVB-induced skin barrier damage in BALB/c hairless mice and human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Skin barrier dysfunction can lead to water and electrolyte loss, triggering homeostatic imbalances that can trigger atopic dermatitis and anaphylaxis. Panax ginseng C.A. Meyer is a traditional Chinese medicinal herb with known therapeutic benefits for the treatment of skin diseases, including photodamage repair effects and reduction of pigmentation. However, few reports exist that describe effectiveness of ginseng active components for repair of skin barrier damage.

MATERIALS AND METHODS

Ginseng oligosaccharide extract (GSO) was prepared from P. ginseng via water extraction followed by ethanol precipitation and resin and gel purification. GSO composition and structural characteristics were determined using LC-MS, HPLC, FT-IR, and NMR. To evaluate GSO as a skin barrier repair-promoting treatment, skin of UVB-irradiated BALB/c hairless mice was treated with or without GSO then skin samples were evaluated for epidermal thickness, transepidermal water loss (TEWL), and stratum corneum water content. In addition, UVB-exposed skin samples and HaCaT cells were analyzed to assess GSO treatment effects on levels of epidermal cornified envelope (CE) protein and other skin barrier proteins, such as filaggrin (FLG), involucrin (IVL), and aquaporin-3 (AQP3). Meanwhile, GSO treatment was also evaluated for effects on UVB-irradiated hairless mouse skin and HaCaT cells based on levels of serine protease inhibitor Kazal type-5 (SPINK5), trypsin-like kallikrein-related peptidase 5 (KLK5), chymotrypsin-like KLK7, and desmoglein 1 (DSG1). These proteins are associated with UVB-induced skin barrier damage manifesting as dryness and desquamation.

RESULTS

GSO was shown to consist of oligosaccharides comprised of seven distinct types of monosaccharides with molecular weights of approximately 1 kDa that were covalently linked together via β-glycosidic bonds. In vivo, GSO applied to dorsal skin of BALB/c hairless mice attenuated UVB-induced epidermal thickening and moisture loss. Furthermore, GSO ameliorated UVB-induced reductions of levels of FLG, IVL, and AQP3 proteins. Additionally, GSO treatment led to increased DSG1 protein levels due to decreased expression of KLK7. In vitro, GSO treatment of UVB-irradiated HaCaT cells led to increases of FLG, IVL, and AQP3 mRNA levels and corresponding proteins, while mRNA levels of desquamation-related proteins SPINK5, KLK5, KLK7, and DSG1 and associated protein levels were restored to normal levels.

CONCLUSION

A P. ginseng oligosaccharide preparation repaired UVB-induced skin barrier damage by alleviating skin dryness and desquamation symptoms, highlighting its potential as a natural cosmetic additive that can promote skin barrier repair after UVB exposure.

Validation of a novel UPLC-HRMS method for human whole-blood cyclosporine and comparison with a CMIA immunoassay

Therapeutic drug monitoring is an essential tool when managing the therapeutic use of immunosuppressant cyclosporine A (CsA) in cases with solid organ transplantation. In China, the concentration of CsA is primarily measured using immunoassays. However, existing literature recommends mass spectrometry as the current gold standard for the quantitation of CsA. In the present study, it was attempted to develop a novel application to determine CsA concentrations by using ultra-performance liquid chromatography coupled to high-resolution mass spectrometry (UPLC-HRMS). This technique was then compared with a commercially available chemiluminescent microparticle immunoassay (CMIA) and it was investigated how clinical factors may contribute to quantitation differences between the two methods. An UPLC-Orbitrap-MS method was developed to determine CsA concentrations and this method was validated using guidelines put forward by the Food and Drug Administration from the US. In total, 127 blood samples were acquired from patients undergoing kidney transplantation and analyzed by UPLC-HRMS and CMIA assays. The novel method provided sensitive, accurate and precise results. The mean CsA concentration measured by CMIA was significantly higher than that measured by UPLC-HRMS (85.70±48.99 vs. 67.06±34.56 ng/ml, P<0.0001). Passing Bablok analysis yielded a slope of 1.34 (95% CI: 1.22-1.47) and an intercept of -2.54 (95% CI: -10.29-5.52). A group of samples with a higher metabolic ratio (hydroxylated CsA/CsA>1) exhibited larger discrepancies, while a group of samples taken from patients with a longer post-transplantation time (>10 years) featured narrow 95% CIs from -15.32 to 65.69%, as determined by Bland-Altman analysis. In summary, a reliable, accurate and rapid UPLC-HRMS method for CsA analysis was successfully developed. The measurement of CsA by the CMIA assay in renal transplant patients should be further evaluated with a specific focus on positive bias.

Sensitive UHPLC–MS/MS method for the determination of tacrolimus in minipig whole blood

Background: Tacrolimus, a potent immunosuppressant drug widely used systemically to reduce the risk of organ rejection in transplants, has been repositioned for topical treatment of atopic dermatitis. Results & methodology: This work describes the optimization of a new method for the determination of tacrolimus in whole blood after topical administration. Sample treatment consisted of an automated procedure based on protein precipitation followed by solid-phase extraction. The present method showed good performance with quantitation limits of 10 pg ml-1 and intra- and interday precision and accuracy lower than 15 and 10%, respectively. Conclusion: A new highly sensitive UHPLC–MS/MS method has been developed enabling a better characterization of the minipig blood plasma pharmacokinetic behavior of tacrolimus after topical administration.

A simple ultra-high-performance liquid chromatography-high resolution mass spectrometry assay for the simultaneous quantification of 15 antibiotics in plasma

Antibiotic (ATB) treatment of critically ill patients with pathophysiological injuries remains a challenge due to the constant increase in antimicrobial resistance. Therapeutic drug monitoring (TDM) is advised for ATB dose adjustments to avoid suboptimal concentrations and dose-related adverse effects. Therefore, a single and reliable analytical method for a broad selection of ATBs was developed using a high-resolution mass spectrometry (HRMS) platform for frequent use in intensive care units. An UHPLC assay coupled to high resolution accurate mass acquisition has been developed for the quantification of penicillins (amoxicillin, oxacillin, piperacillin, and ticarcillin), cephalosporines (cefepime, cefotaxime, ceftazidime, and ceftriaxone), carbapenems (ertapenem, imipenem, and meropenem), lincosamide (clindamycin), quinolones (ofloxacin and ciprofloxacin) and tazobactam. Plasma samples (100μL) were spiked with an internal standard solution followed by protein precipitation. Separation was achieved on an Accucore C18 column, which enabled sample analysis every 9min. All compounds were detected in electrospray positive ion mode and quantified with a linear regression between 0.5 and 32mg/L (r2>0.998). Overall precision and accuracy did not exceed 15%. No significant matrix effect was observed for the studied ATBs. Stored stock solutions at -20°C were stable for 6 months, except for amoxicillin and imipenem. Analytes in plasma were stable for 24h under ambient conditions as well as in post-preparation in an autosampler, except for amoxicillin and imipenem. This HRMS assay provides the simultaneous quantification of 15 ATB; it fulfills the usual quality criteria and was successfully applied for routine TDM of ATBs. The method is based on a full scan acquisition, and it would be easy to add other compounds to the present panel in the future, as this assay has already been proven to be efficient for different classes of compounds.