LC–MS Determination and Pharmacokinetic Study of Salidroside in Rat Plasma after Oral Administration of Traditional Chinese Medicinal Preparation Rhodiola crenulata Extract

Encapsulation and release of salidroside in myofibrillar protein‑sodium alginate gel: Effects of different M/G ratios of sodium alginate

Myofibrillar protein‑sodium alginate (MP-SA) gels play a pivotal role in the development of functional food gels. Salidroside (SAL) is promising component but suffers from low bioavailability, necessitating effective delivery systems. This study introduces M/G ratio factor into classical theoretical MP-based gel models, and use for the SAL delivery. The findings indicate that SA significantly enhances gel properties and functions. Scanning electron microscopy, liquid chromatography, and low-field nuclear magnetic resonance confirmed that the addition of SA improved microstructure, water retention, and thus reduced SAL loss during processing. Digestion simulations revealed the influence of SA type on SAL release kinetics. Molecular docking showed that SA with lower M/G ratio binds more readily to MP, a key determinant of gel performance. These insights provide a novel theoretical basis for MP-SA gels and offer a new perspective on the delivery of bioactive compounds in functional foods.

Anti-senescence effects of Rhodiola crenulate extracts on LO2 cells and bioactive compounds

ETHNOPHARMACOLOGICAL RELEVANCE

Rhodiola crenulata (Rc) is a traditional herb, used in Tibetan medicine, has shown promise efficacy in physical performance improvement, work capacity enhancement, fatigue elimination, and altitude sickness prevention. Also, Rc exhibited therapeutic effects on aging-related diseases. However, relevant researches on Rc and their bioactive components are quite few and needs further investigation.

AIM OF THE STUDY

The objective of this study was to understand the relationship between phytochemical profiles and their activities of Rc extracts.

MATERIALS AND METHODS

Rc extracts prepared by solvents with various hydrophilicity (i.e. aqueous ethanol (70%, v/v), water, and ethyl acetate), and their chemical compositions and specific compounds were analyzed by chemical analysis method and ultra-performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-QTOF-MS). The regulate effects of Rc extracts on senescence and antioxidant activity were evaluated using the models of LO₂ cells and Caenorhabditis elegans.

RESULTS

The 70% ethanol extracts exhibited better regulating effects on senescence via the assays of senescence -associated β-galactosidase (SAβG) staining and lifespan, which was consistent with the higher antioxidant activities observed based on the results of antioxidant assays. A total of 14 phytochemicals have been identified in 70% ethanol extracts, whereas the other two extracts contained much fewer compounds in varieties. Phytochemical profile of water extract was similar to the first half (polar compounds, running time: 0-6 min) of 70% ethanol extract profile, while those of ethyl acetate extract was consistent with its second half (more nonpolar compounds, running time: 6-12 min).

CONCLUSIONS

The 14 phytochemicals in Rc might exhibit additive or synergistic effects on senescence regulating and antioxidant activities, providing theoretical basis for daily administration of Rc.

Lack of salidroside impact on selected cytochromes encoding genes transcription in the liver of ethanol induced rats

Introduction: The molecular basis of in vivo metabolism of selected representatives of phenylethanoids in the presence of ethanol has not been fully elucidated.

Objective: The aim was to estimate a salidroside (Sal) metabolism in the liver tissue in rats with induced alcohol tolerance by assessing changes in the transcription of genes encoding cytochromes: CYP1A2, 2D2, 3A1, 2C23.

Methods: cDNA was synthesized from total RNA isolated from rat liver samples. mRNA level changes were evaluated using real-time PCR (qRT-PCR) technique.

Results: Ethanol caused a significant induction of the CYP1A2 and CYP2C23 genes transcription, and a decrease in the CYP3A1 mRNA level, predominantly without statistical significance. A statistically significant increase of the CYP1A2 mRNA level was observed in the group receiving only Sal (4.5 mg/kg b.w.; p.o.) (p<0.01).

Conclusions: There was no unequivocal effect of salidroside on the transcription of investigated cytochrome genes in the liver of rats with induced alcohol tolerance.

Therapeutic potential of phenylethanoid glycosides: A systematic review

Phenylethanoid glycosides (PhGs) are generally water-soluble phenolic compounds that occur in many medicinal plants. Until June 2020, more than 572 PhGs have been isolated and identified. PhGs possess antibacterial, anticancer, antidiabetic, anti-inflammatory, antiobesity, antioxidant, antiviral, and neuroprotective properties. Despite these promising benefits, PhGs have failed to fulfill their therapeutic applications due to their poor bioavailability. The attempts to understand their metabolic pathways to improve their bioavailability are investigated. In this review article, we will first summarize the number of PhGs compounds which is not accurate in the literature. The latest information on the biological activities, structure-activity relationships, mechanisms, and especially the clinical applications of PhGs will be reviewed. The bioavailability of PhGs will be summarized and factors leading to the low bioavailability will be analyzed. Recent advances in methods such as bioenhancers and nanotechnology to improve the bioavailability of PhGs are also summarized. The existing scientific gaps of PhGs in knowledge are also discussed, highlighting research directions in the future.

An LC-MS/MS method for the determination of salidroside and its metabolite p-tyrosol in rat liver tissues

CONTEXT

Salidroside and its metabolite p-tyrosol are two major phenols in the genus Rhodiola L. (Crassulaceae). They have been confirmed to possess various pharmacological properties and are used for the prophylaxis and therapeutics of many diseases. Several analytical methods have been developed for the determination of the two compounds in plant materials and biological plasma matrices. However, these methods are not optimal for biological samples containing complex organic interferences, such as liver and brain tissues.

OBJECTIVE

This study aimed to further develop and validate a simple and specific LC-MS/MS method for the determination of salidroside and its metabolite p-tyrosol in rat liver tissues using paracetamol as the internal standard (IS).

MATERIALS AND METHODS

Salidroside and p-tyrosol with the IS paracetamol and liver tissues were used as model compounds and biological samples. Samples were processed by protein precipitation (PP) with methanol, the supernatant was dried under nitrogen and the residue was reconstituted in a mobile phase that consisted of a mixture of acetonitrile and water (1:9, v/v). Salidroside and p-tyrosol were detected in negative mode under multiple reaction monitoring (MRM) by a triple quadrupole tandem mass spectrometer coupled with electrospray ionization.

RESULTS

Standard curves were linear over the concentration range of 50-2000 ng/mL with correlation coefficients of 0.995 or better for both salidroside and p-tyrosol. The intra- and inter-day accuracy for salidroside ranged between 104.90 and 112.73% with a precision of 3.51-14.27%. For p-tyrosol, the intra- and inter-day accuracy was between 92.38 and 100.59%, and the precision was 8.54% or less. The stability data showed that no significant degradation occurred under the experimental conditions. The recoveries were 111.44, 108.10, and 102.00% for salidroside at concentrations of 50, 500 and 2000 ng/mL, respectively, and were 105.44, 105.50, and 113.04% for tyrosol at concentrations of 50, 500 and 2000 ng/mL, respectively. The matrix effects were 83.85-92.45% for salidroside and 85.61-92.49% for p-tyrosol at three QC levels. This method was successfully applied to a liver tissue distribution study of salidroside and its metabolite p-tyrosol in rats.

DISCUSSION AND CONCLUSION

This newly established method is validated as simple, reliable and accurate. It can be used as a valid analytical method for the intrinsic quality control of biological matrices, especially tissue samples.

Simultaneous determination of salidroside and its aglycone metabolite p-tyrosol in rat plasma by liquid chromatography-tandem mass spectrometry

Salidroside and its aglycone p-tyrosol are two major phenols in the genus Rhodiola and have been confirmed to possess various pharmacological properties. In our present study, p-tyrosol was identified as the deglycosylation metabolite of salidroside after intravenous (i.v.) administration to rats at a dose of 50 mg/kg, but was not detectable after intragastric gavage (i.g.) administration through HPLC-photodiode array detection (PDA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Next, an accurate and precise LC-MS/MS method was developed to quantitatively determine salidroside and p-tyrosol in rat plasma samples. Samples were analyzed by LC-MS/MS on a reverse-phase xTerra MS C18 column which was equilibrated and eluted with an isocratic mixture of acetonitrile-water (1:9, v/v) at a flow rate of 0.3 mL/min. The analytes were monitored by multiple reaction monitoring (MRM) under the negative electrospray ionization mode. The precursor/product transitions (m/z) were 299.0 → 118.8 for salidroside, 137.0 → 118.9 for p-tyrosol and 150.1 → 106.9 for the internal standard (IS), paracetamol, respectively. The calibration curve was linear over the concentration ranges of 50-2,000 ng/mL for salidroside and 20-200 ng/mL for p-tyrosol. The inter- and intra-day accuracy and precision were within ± 15%. The method has been successfully applied to the pharmacokinetic study and the oral bioavailability was calculated.