Rapid Simultaneous Determination of 43 Pesticide Residues in Schizonepeta tenuifolia by Gas Chromatography Mass Spectrometry

A simple, fast, and reliable method was established for simultaneous determination of 43 pesticides in Schizonepeta tenuifolia. The samples were prepared using solid-phase extraction (SPE) method. Pesticides were extracted from Schizonepeta tenuifolia using acetonitrile, cleaned with Pesticarb/NH2, and eluted by mixed solvents of acetonitrile and toluene (3 : 1, v/v). Selected pesticides were identified using DB-35MS capillary column and detected by gas chromatography mass spectrometry. Samples were quantified by external standard method. Recoveries for the majority of pesticides at spike levels of 0.2, 0.5, and 1 mg kg−1 ranged between 70 and 120% (except for Chlorothalonil, Thiamethoxam, and Dicofol), and the relative standard deviations (RSDs n = 6) were 1.32%–13.91%. Limits of detection (LODs) were 0.0011–0.0135 mg kg−1, whereas limits of quantification (LOQs) were 0.0038–0.0451 mg kg−1. The satisfactory accuracy and precision, in combination with a good separation and few interferences, have demonstrated the strong potential of this technique for its application in Schizonepeta tenuifolia analysis.

Simultaneous determination of three active flavonoids in rat plasma by HPLC-MS/MS: Application to a comparative pharmacokinetic investigation after oral administration of Schizonepeta tenuifolia aqueous extract with and without its volatile oil

Schizonepeta tenuifolia Briq. (ST) has been used as an aromatic exterior-releasing medicine in clinical practice for thousands of years in China. Previous researches have revealed both volatile oil (STVO) and aqueous extract (STAE) from ST showed significant pharmacological activities, such as anti-virus, anti-inflammation, anti-oxidation, and immunoregulation. However, the influence between each other was still unknown. The purpose of this study was to compare the pharmacokinetic profiles of three main flavonoids (luteoloside, apigetrin, and hesperidin) in STAE to illustrate the influence of STVO. A liquid chromatography-tandem mass spectrometry (HPLC-MS) method was established to quantitatively analyze the three absorbed ingredients in the plasma of healthy rats. Biological samples were analyzed on an Agilent Eclipse Plus C18 column (3.0 mm × 150 mm, 3.5 μm) with gradient mobile phase (containing 0.2% formic acid and acetonitrile) at a flow rate of 0.8 mL/min. All the analytes and quercitrin (IS) were investigated with an electrospray ionization source (ESI) using multiple-reaction monitoring (MRM) in negative ionization mode. In addition, this quantitative method showed good linearities (r ≥ 0.9995) and the lower limits of quantification were 0.590–1.19 ng/mL. The intra- and inter-day precisions ranged 3.47–10.45% and 4.29–11.28% for the three analytes. The mean extraction recoveries were in the range of 77.41–109.79% and the average matrix effects were within 83.41–112.67%. The validated method has been fully applied to compare the pharmacokinetic parameters of the three flavonoid glycosides in rat plasma after oral administration of STAE and STAE+STVO. In comparison of luteoloside, apigetrin, and hesperidin in STAE group, it was found that different degree of increasing existed for the time to reach the maximum concentration (Tmax), elimination half-life time (T1/2), the area under the concentration curves (AUC0→t and AUC0→∞) and the maximum concentrations (Cmax) in STAE+STVO group. As can be seen from above results, STVO could improve the absorption and bioavailability of the three analytes. These findings would provide some active and strong basis of safe clinical application for ST and further exploitation for STVO from the perspective of drug–drug interaction.

Simultaneous Determination of Luteoloside, Apigetrin, And Hesperidin In Rat Plasma By UHPLC-MS/MS: Application to A Comparative Pharmacokinetic Investigation After Oral Administration Of Schizonepeta Tenuifolia Aqueous Extract With And Without Its Volatile Oil

Background: Schizonepeta tenuifolia Briq. (ST) has been used as an aromatic exterior-releasing medicine in clinical practice for thousands of years in China. Previous researches have revealed both volatile oil (STVO) and aqueous extract (STAE) from ST showed significant pharmacological activities. However, the influence between each other was still unknown. Methods: This study was designed to compare the pharmacokinetic profiles of three main flavonoids (luteoloside, apigetrin, and hesperidin) in STAE to illustrate the influence of STVO. So, an ultra-flow liquid chromatography-tandem mass spectrometry (UHPLC-MS) method was established to quantitatively analyze the three absorbed ingredients in the plasma of healthy rats. Biological samples were analyzed on an Agilent Eclipse Plus C18 column (3.0 mm × 150 mm, 3.5 μm) with gradient mobile phase (containing 0.2% formic acid and acetonitrile) at a flow rate of 0.8 mL/min. All the analytes and quercitrin (IS) were investigated with an electrospray ionization source (ESI) using multiple-reaction monitoring (MRM) in negative ionization mode. Results: This quantitative method showed good linearities (r ≥0.9995) and the lower limits of quantification were 0.590~1.19 ng/ml. The intra- and inter-day precisions ranged 3.47~10.45% and 4.29~11.28% for the three analytes. The mean extraction recoveries were in the range of 77.41~109.79% and the average matrix effects were within 83.41~112.67%. The validated method has been fully applied to compare the pharmacokinetic parameters of the three flavonoid glycosides in rat plasma after oral administration of STAE and STAE+STVO. In comparison of luteoloside, apigetrin, and hesperidin in STAE group, it was found that different degree of increasing existed for the time to reach the maximum concentration (Tmax), elimination half-life time (T1/2), the area under the concentration curves (AUC0→t and AUC0→∞) and the maximum concentrations (Cmax) in STAE+STVO group. Conclusions: As can be seen from above, STVO could improve the absorption and bioavailability of the three analytes. These findings would provide some active and strong basis of safe clinical application for ST and further exploitation for STVO from the perspective of drug-drug interaction.

Schizonepeta Tenuifolia with Alpinia Oxyphylla Alleviates Atopic Dermatitis and Improves the Gut Microbiome in Nc/Nga Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease that may be related to gut microbes. Schizonepeta Tenuifolia Briquet (STB) and Alpinia Oxyphylla Miquel (AOM) has traditionally been used for anti-inflammatory activity. We evaluated the effects of STB, AOM and STB+AOM extracts on 2,4-dinitro-1-chlorobenzene (DNCB)-induced AD skin lesions in Nc/Nga mice and action mechanism was explored. AD lesions were induced in the dorsal skin of Nc/Nga mice by topical application of 1% followed by 0.2% DNCB. After DNCB was applied, the mice had topical applications of either 30% water, 0.01% dexamethasone, 30% STB, 30% AOM, 15% STB + 15% AOM extracts in butylene glycol (BG). Each group was also fed corresponding high-fat diets with 1% dextrin (AD-Con and AD-Positive), 1% STB (AD-STB), 1% AOM (AD-AOM) and 0.5% STB + 0.5% (AD-MIX). Normal-control mice had no DNCB application. The study evaluated the skin AD severity, scratching behavior and weight changes of AD mice for 5 weeks. Compared with AD-Con, AD-STB, AD-AOM and AD-MIX alleviated the clinical AD symptoms (erythema, pruritus, edema, erosion and lichenification and scratching behaviors), normalized immune chemistry (serum IgE concentration, mast cells and eosinophil infiltration), improved skin hyperplasia and enhanced the gut microbiome. AD-STB, AD-AOM, AD-MIX and AD-positive treatments inhibited cutaneous mRNA expression of TNF-α, IL-4 and IL-13 and serum IgE concentrations. AD-MIX most effectively reduced clinical AD symptoms and proinflammatory cytokines. AD-Positive also reduced them but serum GOT and GPT concentrations were abnormally high. AD-STB and AD-MIX increased the alpha-diversity of fecal bacteria and reduced the serum acetate concentration, compared to the AD-Con. In conclusion, the mixture of STB and AOM is effective for treating AD symptoms locally and systemically without adverse effects and are potential interventions for atopic dermatitis.