Simultaneous separation and determination of seven biphenyl cyclooctene lignans in Schisandra chinensis and its preparations by micellar electrokinetic chromatography with dual organic solvent system

INTRODUCTION

Gomisin is a natural dibenzo cyclooctene lignan, which is mainly derived from the family Magnoliaceae. It has anti-inflammatory, antioxidant, anti-tumor, anti-aging, and hypoglycemic effects. Gomisins play important roles as medicines, nutraceuticals, food additives, and cosmetics.

OBJECTIVE

The objective of this study is to establish a micellar electrokinetic chromatography (MEKC) method for simultaneous separation and determination of seven biphenyl cyclooctene lignans (Gomisin D, E, G, H, J, N, and O) in Schisandra chinensis and its preparations.

METHODS

The method was optimized by studying the effects of the main parameters on the separation. The method has been validated and successfully applied to the determination of seven Gomisins in S. chinensis and its preparations.

RESULTS

In the separation system, the running buffer was composed of 20 mM Na2HPO4, 8.0 mM sodium dodecyl sulfate (SDS), 11% (v/v) methanol, and 6.0% (v/v) ethanol. A diode array detector was used with a detection wavelength of 230 nm, a separation voltage of 17 kV, and an operating temperature of 25°C. Under this condition, the seven analytes were separated at baseline within 20 min, and a good linear relationship was obtained with correlation coefficient ranging from 0.9919 to 0.9992. The limit of detection (LOD, S/N = 3) and the limit of quantification (LOQ, S/N = 10) ranged from 0.8 to 0.9 μg/mL and from 2.6 to 3.0 μg/mL, respectively. The recovery rate was between 99.1% and 102.5%.

CONCLUSION

The experimental results indicated that this method is suitable for the separation and determination of seven Schisandra biphenyl cyclooctene lignan compounds in real samples. At the same time, it provides an effective reference for the quality control of S. chinensis and its preparations.

The therapeutic mechanism of Yuye decoction on type 2 diabetes mellitus based on network pharmacology and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Yuye decoction (YYD) has been widely used as a folk Chinese herbal formula in clinical treatment of type 2 diabetes mellitus(T2DM) for many years. However, its mechanism is still unclear.

AIM OF THE STUDY

The aim of this study was to explore the potential mechanism of YYD against T2DM initially by UHPLC-MS/MS combining with network pharmacology, molecular docking techniques and experimental validation.

MATERIALS AND METHODS

The main ingredients in the water extract of YYD were initially identified using UHPLC-MS/MS analysis. Combined with network pharmacology and molecular docking techniques, the YYD key compounds-core targets-key signaling pathways network was constructed and the binding activity of key components to core targets was validated. The T2DM rat model was induced by Streptozotocin combined with high glucose and high fat diets. The apoptosis cell model of mouse islet β-cell of Min6 was induced by high-glucose and palmitic acid. Histopathological and immunofluorescence satining were used to evaluate pancreatic islet β-cell function and apoptosis in rats. Min6 cell viability and apoptosis ratio were evaluated by CCK-8 and TUNEL staining. The predicted targets and pathways were validated by experiments in vitro and in vivo.

RESULTS

The 56 compounds from YYD were identified by UHPLC-MS/MS. The potential targets of the above compounds were predicted by online compound target database, among of which 362 targets were associated with T2DM. Protein-protein interaction analysis identified the main targets such as SRC, MAPK1, PIK3R1, AKT1, HRAS and HSP90AA1, which were considered as the therapeutic targets of YYD on against T2DM. Functional enrichment analysis revealed that PI3K/AKT, FoxO and apoptosis signaling pathways were significantly enriched. Molecular docking results showed that compounds of monolinolein, neomangiferin, mangiferin, pelargonidin-3-O-glucoside and acacetin from YYD had high binding activities to PIK3R1, AKT1, Sirt1 and FoxO1. Therefore, PI3K/AKT1, Sirt1/FoxO1 and apoptotic signaling pathways were considered as predicted targets for experimental validation study. Animal experiments showed that YYD reduced blood glucose levels, improved pancreatic dysfunction and pancreatic islet β-cells apoptosis in T2DM rats which contributed to the activation of AKT1 and FoxO1 and their related signaling molecules. These results were confirmed in Min6 cell model induced by high-glucose and palmitic acid.

CONCLUSIONS

In summary, this study systematically visualized the possible therapeutic effects and mechanisms of YYD on T2DM through the network pharmacology approach and experimental study. The results indicated that YYD could prevent pancreatic islet dysfunction and reverse islet of β-cells apoptosis possibly via PI3K/AKT1, Sirt1/FoxO1 signaling pathways.

Authentication of Schisandra chinensis and Schisandra sphenanthera in Chinese patent medicines

Authentication of species is crucial for ensuring the safety and efficacy of herbal medicines. The fruits of Schisandra chinensis and S. sphenanthera have been used for the same traditional Chinese drug, Wuweizi, but are found to be quite different according to their constituents, pharmacological effects, and qualities. These two fruits have been recorded as Schisandrae Chinensis Fructus (Wuweizi) and Schisandrae Sphenantherae Fructus (Nan-wuweizi), respectively, by Chinese Pharmacopoeia, 2000 edition. However, Nan-wuweizi is often found to be taken as Wuweizi in some Chinese patent drugs intentionally or by mistake because of its lower price and similar characteristics to Wuweizi. In this study, the selection and validation of special chemical markers for the identification of Schisandra species were established by HPLC-DAD-MS profiling analysis. Simple TLC and HPLC methods were proposed for the accurate determination of Nan-wuweizi from Wuweizi in Chinese patent medicines, using schisandrin and anwulignan as the identifying markers for Wuweizi and Nan-wuweizi, respectively. Through the establishment of a statistical model, adulterated or misused ratios of Nan-wuweizi in Wuweizi (w/w), as well as in Fenghan Kesou pills, can be determined. The limit of detection of Nan-wuweizi in a mixture (w/w) using both TLC and HPLC methods is 5% (mixed crude drugs of 50mg and 5g in a 1000g prescribed amount). The constructed statistical model relating the HPLC peak area ratio (anwulignan/schisandrin) and adulteration ratio is suitable for mixed crude drugs and Fenghan Kesou pills, and the two fitting equations have a good correlation (r=0.9979). Furthermore, 36 commercial Chinese patent medicines containing Wuweizi or Nan-wuweizi according to their labels were checked by these methods, and Nan-wuweizi was detected in Renshen Wuweizi Granules and Fenghan Kesou Pills. The ratios of Nan-wuweizi in these mixtures (w/w) were 100:0 for both, which does not comply with the statutory prescription. This study provided a simple and reliable method to prevent the adulteration or misuse of Nan-wuweizi in crude drugs and patent medicines of Wuweizi.